url
stringlengths 14
1.76k
| text
stringlengths 100
1.02M
| metadata
stringlengths 1.06k
1.1k
|
|---|---|---|
https://dsp.stackexchange.com/questions/72261/removing-cracking-in-real-time-audio-filtering | # Removing cracking in real time audio filtering
I am getting back to DSP applications after a while and I've written a real time audio player in Python.
Basically I'm reading chunks of data from a .wav file (I am doing this to simulate a real time scenario, where I receive real time audio input from a source) and I am playing each chunk in real time applying a simple filter with a dynamic highcut frequency: it starts from 300Hz and then gradually moves until 20000Hz (basically no high-cut).
I am using PyAudio for the real time playing and scipy for the simple filter. The code is the following, it is self-contained and reproducible, you have just to change the filename variable with the path of your wave file.
import pyaudio
import wave
import time
import numpy as np
import scipy.io.wavfile as sw
import librosa
import scipy
import sys
from scipy.io.wavfile import write
############ Global variables ###################
filename = '../wav/The_Weeknd.wav' #Test file
chunk = 512 #frame size
#Conversion from np to pyAudio types
np_to_pa_format = {
np.dtype('float32') : pyaudio.paFloat32,
np.dtype('int32') : pyaudio.paInt32,
np.dtype('int16') : pyaudio.paInt16,
np.dtype('int8') : pyaudio.paInt8,
np.dtype('uint8') : pyaudio.paUInt8
}
np_type_to_sample_width = {
np.dtype('float32') : 4,
np.dtype('int32') : 4,
np.dtype('int16') : 3,
np.dtype('int8') : 1,
np.dtype('uint8') : 1
}
STEREO = 2 #channels
#################################################
# Simple class which reads an input test wav file and reproduce it in a real time fashion. Used to test real time functioning.
class Player:
def __init__(self):
self.input_array, self.sample_rate = librosa.load(filename, sr=44100, dtype=np.float32, duration=60)
#print(self.sample_rate)
#print(self.input_array.shape)
self.cycle_count = 0
self.highcut = 300
def bandPassFilter(self,signal, highcut):
fs = 44100
lowcut = 20
highcut = highcut
nyq= 0.5 * fs
low = lowcut / nyq
high = highcut / nyq
order = 2
b, a = scipy.signal.butter(order, [low,high], 'bandpass', analog=False)
y = scipy.signal.filtfilt(b,a,signal, axis=0)
return(y)
def pyaudio_callback(self,in_data, frame_count, time_info, status):
audio_size = np.shape(self.input_array)[0]
#print(audio_size)
print('frame count: ', frame_count)
if frame_count*self.cycle_count > audio_size:
# Processing is complete.
print('processing complete')
return (None, pyaudio.paComplete)
elif frame_count*(self.cycle_count+1) > audio_size:
# Last frame to process.
print('1 left frame')
frames_left = audio_size - frame_count*self.cycle_count
else:
# Every other frame.
print('everyotherframe')
frames_left = frame_count
data = self.input_array[frame_count*self.cycle_count:frame_count*self.cycle_count+frames_left]
data = self.bandPassFilter(data, self.highcut)
if(self.highcut<20000):
self.highcut += 10
print('len of data', data.shape)
#write('test.wav', 44100, data) #Saves correctly the file!
out_data = data.astype(np.float32).tobytes()
print('printing length: ',len(out_data))
#print(out_data)
self.cycle_count+=1
print(self.cycle_count)
print('pyaudio continue value: ',pyaudio.paContinue)
return (out_data, pyaudio.paContinue)
def start_non_blocking_processing(self, save_output=True, frame_count=2**10, listen_output=True):
'''
Non blocking mode works on a different thread, therefore, the main thread must be kept active with, for example:
while processing():
time.sleep(1)
'''
self.save_output = save_output
self.frame_count = frame_count
# Initiate PyAudio
self.pa = pyaudio.PyAudio()
# Open stream using callback
self.stream = self.pa.open(format=np_to_pa_format[self.input_array.dtype],
channels=1,
rate=self.sample_rate,
output=listen_output,
input=not listen_output,
stream_callback=self.pyaudio_callback,
frames_per_buffer=frame_count)
# Start the stream
self.stream.start_stream()
def processing(self):
'''
Returns true if the PyAudio stream is still active in non blocking mode.
MUST be called AFTER self.start_non_blocking_processing.
'''
return self.stream.is_active()
def terminate_processing(self):
'''
Terminates stream opened by self.start_non_blocking_processing.
MUST be called AFTER self.processing returns False.
'''
# Stop stream.
self.stream.stop_stream()
self.stream.close()
# Close PyAudio.
self.pa.terminate()
# Resets count.
self.cycle_count = 0
# Resets output.
self.output_array = np.array([[], []], dtype=self.input_array.dtype).T
if __name__ == "__main__":
print('RUNNING MAIN')
player = Player()
player.start_non_blocking_processing()
while(player.processing()):
time.sleep(0.1)
player.terminate_processing()
What I am doing is simply read chunks of audio from the wav file, process them applying a filter to the single chunk of data and then send that chunk to audio playing.
The code works fine, the audio is correctly reproduced and the filter does its job.
The problem is that I get audio crackles in audio reproduction and I can't figure out why. I studied DSP in the past and I know techniques such as overlap and add ecc... but it's been a while and i don't know if they could solve my problem (or the "error" lies somewhere else)
Couple of things:
• You really can't print to the console in a high-speed context, especially not in audio callback functions. That printing has side effects, and it's slower than you think, I promise. This alone breaks "real-timedness": You can never guarantee how fast your printing is (or isn't).
• Ahhhh! You're re-designing the filter for every single piece of audio! That's terrible! It's always the same filter. Calculate it once, and apply it forever.
• filtfilt is not the function you need. I saw that a hundred times: People use filtfilt because it has a name that reads a bit like it's the filtering operation they want, but it's not. You just need plain convolution.
• After fixing these showstoppers, you still need to be aware that filters have state, so you need to save the filter state after each bit of filtered audio for the next part.
• Yes, I'm totally aware of the first 2 points! It's a small experimental code, so those things (prints ecc...) are going to be removed for the final application. Anyway I'm declaring the filter everytime because I want to apply a dynamic high cut (so not a fixed one). From the theoretical point of view, I was worried about the cracking sound I get, which one is the cause of this problem? – Mattia Surricchio Dec 28 '20 at 11:33
• yes, but doing this in the real-time context introduces non-deterministic varying and most importantly large latency, which is one of the reasons you get the non-continuous effects. You can't do this later, this needs to be fixed first. These are not "non-pretty", these are bugs. All four of the reasons I've mentioned are critical and can/will/do lead to cracks. – Marcus Müller Dec 28 '20 at 13:11
• to make your filter adjustable, you really don't have to recalculate it every time – you should do that only when it actually changes, and outside of the callback function, and with a safe way of switching or transitioning between the old and the new filter, and you still need to keep your filter state. – Marcus Müller Dec 28 '20 at 13:14
• overlap and save solves exactly the fourth point. – Marcus Müller Dec 28 '20 at 14:07
• If the crack is periodic on the order of your processing batch (every N samples) then there is almost certainly an issue with your filter states as @MarcusMüller is saying. You want to carry over those tap values between batches. – Keegs Dec 28 '20 at 18:14
Thanks to @Marcus Muller answer and comments in my question, I managed to solve th problem. As he pointed out:
filtfilt is not the function you need. I saw that a hundred times: People use filtfilt because it has a name that reads a bit like it's the filtering operation they want, but it's not. You just need plain convolution.
After fixing these showstoppers, you still need to be aware that filters have state, so you need to save the filter state after each bit of filtered audio for the next part.
These 2 points were the major problem in my code. filtfilt is not meant to work in real time scenarios, while lfilter is better in these cases, you can find a really useful comparison here: lfilter vs filtfilt
The full working code is the following, it basically plays a .wav audio in real time and adds a dynamic filter to it. The final result will be a sliding cut-off frequency while the audio is playing.
import pyaudio
import wave
import time
import numpy as np
import scipy.io.wavfile as sw
import librosa
import scipy.signal
import scipy
import sys
from scipy.io.wavfile import write
############ Global variables ###################
filename = '../wav/The_Weeknd.wav' #Test file
chunk = 512 #frame size
#Conversion from np to pyAudio types
np_to_pa_format = {
np.dtype('float32') : pyaudio.paFloat32,
np.dtype('int32') : pyaudio.paInt32,
np.dtype('int16') : pyaudio.paInt16,
np.dtype('int8') : pyaudio.paInt8,
np.dtype('uint8') : pyaudio.paUInt8
}
np_type_to_sample_width = {
np.dtype('float32') : 4,
np.dtype('int32') : 4,
np.dtype('int16') : 3,
np.dtype('int8') : 1,
np.dtype('uint8') : 1
}
STEREO = 2 #channels
#################################################
# Simple class which reads an input test wav file and reproduce it in a real time fashion. Used to test real time functioning.
class Player:
def __init__(self):
self.input_array, self.sample_rate = librosa.load(filename, sr=44100, dtype=np.float32, duration=60)
#print(self.sample_rate)
#print(self.input_array.shape)
self.cycle_count = 0
self.highcut = 300
self.filter_state = np.zeros(4)
def bandPassFilter(self,signal, highcut):
fs = 44100
lowcut = 20
highcut = highcut
nyq= 0.5 * fs
low = lowcut / nyq
high = highcut / nyq
order = 2
b, a = scipy.signal.butter(order, [low,high], 'bandpass', analog=False)
y, self.filter_state = scipy.signal.lfilter(b,a,signal, axis=0, zi=self.filter_state) # NB: filtfilt needs forward and backward information to filter. So it can't be used in realtime filtering where i have no info about future samples! lfilter is better for real time applications!
return(y)
def pyaudio_callback(self,in_data, frame_count, time_info, status):
audio_size = np.shape(self.input_array)[0]
#print(audio_size)
#print('SIGNORAAAAAA')
#print('frame count: ', frame_count)
if frame_count*self.cycle_count > audio_size:
# Processing is complete.
#print('processing complete')
return (None, pyaudio.paComplete)
elif frame_count*(self.cycle_count+1) > audio_size:
# Last frame to process.
#print('1 left frame')
frames_left = audio_size - frame_count*self.cycle_count
else:
# Every other frame.
#print('everyotherframe')
frames_left = frame_count
data = self.input_array[frame_count*self.cycle_count:frame_count*self.cycle_count+frames_left]
data = self.bandPassFilter(data, self.highcut)
if(self.highcut<20000):
self.highcut += 1
#print('len of data', data.shape)
#write('test.wav', 44100, data) #Saves correctly the file!
out_data = data.astype(np.float32).tobytes()
#print('printing length: ',len(out_data))
#print(out_data)
self.cycle_count+=1
#print(self.cycle_count)
#print('pyaudio continue value: ',pyaudio.paContinue)
return (out_data, pyaudio.paContinue)
def start_non_blocking_processing(self, save_output=True, frame_count=2**10, listen_output=True):
'''
Non blocking mode works on a different thread, therefore, the main thread must be kept active with, for example:
while processing():
time.sleep(1)
'''
self.save_output = save_output
self.frame_count = frame_count
# Initiate PyAudio
self.pa = pyaudio.PyAudio()
# Open stream using callback
self.stream = self.pa.open(format=np_to_pa_format[self.input_array.dtype],
channels=1,
rate=self.sample_rate,
output=listen_output,
input=not listen_output,
stream_callback=self.pyaudio_callback,
frames_per_buffer=frame_count)
# Start the stream
self.stream.start_stream()
def processing(self):
'''
Returns true if the PyAudio stream is still active in non blocking mode.
MUST be called AFTER self.start_non_blocking_processing.
'''
return self.stream.is_active()
def terminate_processing(self):
'''
Terminates stream opened by self.start_non_blocking_processing.
MUST be called AFTER self.processing returns False.
'''
# Stop stream.
self.stream.stop_stream()
self.stream.close()
# Close PyAudio.
self.pa.terminate()
# Resets count.
self.cycle_count = 0
# Resets output.
self.output_array = np.array([[], []], dtype=self.input_array.dtype).T
if __name__ == "__main__":
print('RUNNING MAIN')
player = Player()
player.start_non_blocking_processing()
while(player.processing()):
time.sleep(0.1)
player.terminate_processing()
NB: the code is still a prototype and still has some problems, in particular the following one as mentioned by Marcus:
Ahhhh! You're re-designing the filter for every single piece of audio! That's terrible! It's always the same filter. Calculate it once, and apply it forever.
I have been trying to find a nice way to create a "dynamic" filter (changing the cut-off frequency without re-create the filter each time) but I haven't found a nicer solution.
• why don't you ask "how can I implement a dynamic filter" (describing how dynamic "dynamic" is, and the application of it, and constraints) as a new question? Certainly will be read by more people than your plea for comments here! – Marcus Müller Dec 29 '20 at 12:23
• You are definitely right! – Mattia Surricchio Dec 29 '20 at 12:26
• A quick and dirty way of dynamically changing your filter is to calculate a, b = scipy.signal.butter in a separate thread and send it to your audio thread. Too-large jumps in filter characteristics will cause their own clicks & pops. – TimWescott Dec 29 '20 at 22:49 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.17939843237400055, "perplexity": 6271.8764134014955}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-25/segments/1623487598213.5/warc/CC-MAIN-20210613012009-20210613042009-00480.warc.gz"} |
http://math.stackexchange.com/users/20570/eladidan?tab=activity | Reputation
Next privilege 250 Rep.
Sep 24 awarded Autobiographer Jul 21 revised Show solution to ODE's fourier series is a series of sines only edited body Jul 21 comment Show solution to ODE's fourier series is a series of sines only Then I don't get it: The ODE itself has nothing to do with this result? It all comes strictly from the boundary values? Jul 21 comment Show solution to ODE's fourier series is a series of sines only @AndrewD I guess this is theorem: en.wikipedia.org/wiki/… I guess we can't use the theorem since $u$ doesn't necessarily has a bounded variation. Jul 21 comment Show solution to ODE's fourier series is a series of sines only @AndrewD There was actually another segment in the question asking us to explain why we cannot apply that theorem to conclude 2 but since I didn't know the theorem or its terms to quote, I didn't bring it in. Could you give a link to the theorem in question? We are also hinted that we should derive 2 by developing the coefficients of the Fourier series. Jul 21 asked Show solution to ODE's fourier series is a series of sines only Jul 19 accepted Find roots of $3z^{100} - e^z$ in the unit disc. Jul 15 awarded Teacher Jul 14 revised Find roots of $3z^{100} - e^z$ in the unit disc. circle->disc Jul 14 answered Find roots of $3z^{100} - e^z$ in the unit disc. Jul 14 revised Find roots of $3z^{100} - e^z$ in the unit disc. correction from the comments Jul 14 comment Find roots of $3z^{100} - e^z$ in the unit disc. @AntonioVargas oh boy, what a blunder. Thanks for setting me straight Jul 14 comment Find roots of $3z^{100} - e^z$ in the unit disc. @AntonioVargas, on $0$, $e^z=1$ is greater than $3z^{100}=0$ and on $1$ for example, $3z^{100}=3$ and $e^z=e<3$ Jul 14 asked Find roots of $3z^{100} - e^z$ in the unit disc. Jul 11 accepted Show that $\sum_{k=1}^{n}a_ke^{2 \pi ikx}$ has a root in $\left[ 0,1 \right]$ Jul 11 awarded Commentator Jul 11 comment Show that $\sum_{k=1}^{n}a_ke^{2 \pi ikx}$ has a root in $\left[ 0,1 \right]$ D'oh! I poisoned the internet Jul 11 asked Show that $\sum_{k=1}^{n}a_ke^{2 \pi ikx}$ has a root in $\left[ 0,1 \right]$ Jul 11 comment Show that the complex closed line integral $\oint\frac{\mathrm{d}z}{p(z)}$ is $0$ ($p$ is polynomial) Yeah, the fact that the roots are distinct is relevant to the rest of the question which I didn't present here. I just didn't want to leave it out in case it somehow is needed Jul 10 accepted Show that the complex closed line integral $\oint\frac{\mathrm{d}z}{p(z)}$ is $0$ ($p$ is polynomial) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9128331542015076, "perplexity": 395.8343192201669}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-07/segments/1454701164289.84/warc/CC-MAIN-20160205193924-00106-ip-10-236-182-209.ec2.internal.warc.gz"} |
http://stats.stackexchange.com/questions/45907/efficient-fitting-of-noncentral-chi-squared-distribution-to-data | # Efficient fitting of noncentral chi-squared distribution to data?
I am looking for the most efficient way to fit a noncentral chi-squared distribution with fixed d.o.f. to a given data set. So the inputs are d.o.f. and the data and the output should be the noncentrality parameter that gives the best (maximum likelihood? or any other approach that would be more computationally efficient).
Since on Wikipedia the expression for the noncentral chi2 pdf is an infinite sum of chi2 I am at a bit of a loss as to where to start. Might it be possible to find an analytic MLE for the noncentrality in case of fixed dof? Or any other tricks or cancellations that might simplify the likelihood calculation in this special case.
-
Thanks - I am using MATLAB and have implemented a similar approach using mle and ncx2pdf etc but it is extremely slow so I am looking to implement a more efficient approach myself. – thrope Dec 14 '12 at 14:35
What is the sample size? In R, it takes less than $1$ second to botain the MLE using a sample size $n=1000$. Chek data = rchisq(1000,1,1); ll = function(par){ if(par[1]>0)&par[2]>0) return(-sum(dchisq(data,df=par[1],ncp=par[2],log=T))) else return(Inf) }; optim(c(1,1),ll). – user10525 Dec 14 '12 at 14:46
OK maybe "extremely slow" was a bit strong. It takes me 0.5s for a sample size of 10000... but this is something I will need to perform many times so I really want it to be as fast as possible. – thrope Dec 14 '12 at 14:50
Just use the method of moments : the mean of a non central chi square $\chi^2(k,\lambda)$ is $k+\lambda$, ($k$ is the dof and $\lambda$ the ncp). So take $\lambda$ equal to the mean of the data minus $k$.
If the underlying distribution of your data is really a $\chi^2(k,\lambda)$ this is enough. For theoretical considerations, read Wikipedia on the method of moments – Elvis Dec 14 '12 at 14:48 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7683994174003601, "perplexity": 491.4621506068567}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802769121.74/warc/CC-MAIN-20141217075249-00078-ip-10-231-17-201.ec2.internal.warc.gz"} |
https://www.gamedev.net/forums/topic/215076-need-help-with-reading-from-a-file/ | Public Group
#### Archived
This topic is now archived and is closed to further replies.
# need help with reading from a file...
This topic is 5234 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.
## Recommended Posts
high, im working on a map editor for my pacman clone. anyway, i have finished most of the map editor. the only problem is ive never worked with reading/writing to a file before. i read some tutorials at gametutorials.com and figured out how to write to a file real easy. its the reading in of the file im having problems with. this is obviously a tile based game/map maker, my map array is [19][25] (y)(x). anyway, this is what my Save() function looks like:
void Save()
{
ofstream fout;
fout.open("map.txt");
for(int y = 0; y < 19; y++)
{
for(int x = 0; x < 25; x++)
{
fout << map[y][x];
}
fout<<endl;
}
fout.close();
}
now here is what a typical map.txt looks like if i save from inside my map editor:
1111111111100011111111111
1715888888881700017888888881517
17811811118170001781111811817
17811811118171111781111811817
178884848884882488848488817
17811817811181118111817811817
178888174888481784888417888817
171118171111181781111117811117
00017817888884848888817817000
111181781111111111181781111
888848881717071330171788848888
1111817178171701200017178171781111
00017817178171711111171781717817000
11118171788868886888171781111
178888171718178171717817811717888817
17811868881781717178178888811817
178111811118171717811118111817
17158885888858885888858881517
1111111111111111111111111
now, does anyone have any ideas on how i could read this file back into my map[][] array? im really knew to file input/output so any help is greatly appreciated. this is what i tried but its not working.
void Open()
{
ifstream file_in("map.txt");
if(!file_in)
return;
int x = 0;
int y = 0;
char temp;
while(y != 19) // Keep going until we reach the end of the map
{
file_in >> temp;
map[y][x] = temp;
// Increment 'x' every time we write a character until 'x' equals the
// width of map, then start 'x' back at zero
if(++x == 25)
{
x = 0;
y++; // We need to increment y so we effectively go down to the next line
}
} // end of
file_in.close();
}//end of open()
thanks for any help!! [edited by - graveyard filla on March 23, 2004 3:26:47 AM]
##### Share on other sites
also, i think that my open() function isnt working because some of the enums that represent tiles are 2 digits (see numbers like 17, 12, 11, ETC.) and some are 1 digit (1,2,0,4, ETC)
i think this is why its not working, although i dont really know what im doing so the whole function could be total crap. thanks again for any help
##### Share on other sites
I had pretty much the same problem.. The problem is that when you are reading from file with >> operator, it reads so long that it finds a free space, so right now it will read a whole file in a first place.
change this line in Save() function:
fout << map[y][x];
to:
fout << map[y][x] << ' ';
and it should work..
btw. Those if/while loops in your open function looks pretty creepy, I would consider of changing them to for loops.. :-O
[edited by - Mkk on March 23, 2004 4:01:06 AM]
##### Share on other sites
hey,
actually, that didnt work. well, i figured i was causing problems by outputting my map the way i did (with being able to see the map as a 25x19 array in the map.txt file. anyway, i changed the format to this:
void Save(){ ofstream fout; // Here we create an ofstream and we will call it "fout", like "cout". fout.open("map.txt"); // We call a function from our ofstream object called open(). // We just tell open() the file name we want to open or create. // If the file doesn't exist, it will create it for us once we start writing to it. for(int y = 0; y < 19; y++) { for(int x = 0; x < 25; x++) { fout << map[y][x]; } } // close() closes the file for us. (very important) fout.close();}
anyway, if you dont understand what im saying, this output .txt file now looks like this:
00000000002222222222222222222222222222220000000000000000000000003333333333333333333333333333333333333333333309000000000000000033333333
anyway, this didnt work either. then i tried adding in the little space like you said, and that worked.
but id still like to know why my original way wasnt working. id like my map txt files to be somewhat readable if its possible
[edited by - graveyard filla on March 23, 2004 3:59:32 AM]
##### Share on other sites
By "readable" you mean, readable by a user who opens the file with a text-editor?
Anyways, I''d highly recommend a binary file format, because problems like digits per entry (as mentioned in a posting above) won''t occur. Furthermore, binary file format saves space on the harddisk.
You will need a kind of map editor anyways, because THAT''s what makes the map really "readable"
Indeterminatus
--si tacuisses, philosophus mansisses--
##### Share on other sites
You better look into binary files. They make it alot easier and you can also add in a file header so you can maintain file versions. For example:
struct PACMANFILEHEADER{ DWORD dwType; DWORD dwVersion; WORD wWidth; WORD wHeight;};
dwType
Type of file. You could make the value something you can recognize. For example: 0xAE
dwVersion
Version of the file. For now, just use MAKELONG(1, 0). To compare after you are done with loading, do:
if (Header.dwVersion != MAKELONG(1, 0)) // Error!
After you added new features to your game and updated the map editor, you can write the new loading code. In essence, you can even make the maps backwards compatible with loading. If you do this, you could release a new EXE and still be able to load older maps without all the new nifty features.
wWidth
The width of the map. If you implement variable map sizes in your game you actually have a pretty neat feacture
wHeight
The height of the map. Same as wWidth, having variabele map sizes is just cool. Don't forget to fix smooth scrolling
Ok, now we have that, we can do this:
// Psuedo codeifstream File;File.open("Map1.pac", ios::binary);File.read((char *)&Header, sizeof(PACMANFILEHEADER));
After you read the header, do your checks, allocate the map data and the data at once:
File.read((char*)Map, sizeof(TileSize * (FileHeader.wWidth * FileHeader.wHeight));
This will load the map into memory and viola, you have you map easily loaded.
Saving is the same, but viceversa:
- Open output file
- Write map data
- Close file
Toolmaker
-Earth is 98% full. Please delete anybody you can.
[edited by - toolmaker on March 23, 2004 4:18:00 AM]
##### Share on other sites
Forget the above post. I should read more carefully before replying :/.
The first version didn''t work because the stream "tokenizes" the string it reads, meaning that single entries are delimited with either spaces or newlines.
If you skip those spaces, on LINE would be read by the stream at once, leading to an I/O error (since you''ll try to read over the end of the file).
Indeterminatus
--si tacuisses, philosophus mansisses--
##### Share on other sites
quote:
Original post by Indeterminatus
Forget the above post. I should read more carefully before replying :/.
I sure hope you don''t mean my post It''s pretty constructive and the way things are being handled by others too.
Toolmaker
-Earth is 98% full. Please delete anybody you can.
##### Share on other sites
It wasn´t working at first place because this line:
file_in >> temp;
It will read the file so long until it hits the free space in the file so if you don´t have any free spaces in the file, it will read the whole file in to the variable at the first place (rather than reading just one number).
That´s why the spaces.. so >> operator understands to stop reading after the number.
If you want to those line changes, atleast I just putted
"\n" always after row and it didn´t make any problems.
Here´s my loops for reading writing:
for (int x = 0; x < BOARD_WIDTH; x++){ for (int y = 0; y < BOARD_HEIGHT; y++) { in >> gameBoard[x][y]; }}
Writing:
for (int x = 0; x < BOARD_WIDTH; x++){ for (int y = 0; y < BOARD_HEIGHT; y++) { out << gameBoard[x][y] << ' '; } out << "\n";}
[edited by - Mkk on March 23, 2004 4:24:08 AM]
##### Share on other sites
quote:
I sure hope you don''t mean my post It''s pretty constructive and the way things are being handled by others too.
Sorry, Toolmaker . Of course I was referencing MY previous post, that would be the one before yours .
Should have made it absolute, not relative ...
Indeterminatus
--si tacuisses, philosophus mansisses--
1. 1
2. 2
3. 3
Rutin
22
4. 4
JoeJ
17
5. 5
• 14
• 30
• 13
• 11
• 11
• ### Forum Statistics
• Total Topics
631774
• Total Posts
3002295
× | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.18328894674777985, "perplexity": 3566.0699345062103}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-30/segments/1531676593223.90/warc/CC-MAIN-20180722120017-20180722140017-00476.warc.gz"} |
https://www.ias.ac.in/listing/bibliography/jess/Anandakumar_Karipot | • Anandakumar Karipot
Articles written in Journal of Earth System Science
• Estimating gross primary productivity of a tropical forest ecosystem over north-east India using LAI and meteorological variables
Tropical forests act as a major sink of atmospheric carbon dioxide, and store large amounts of carbon in biomass. India is a tropical country with regions of dense vegetation and high biodiversity. However due to the paucity of observations, the carbon sequestration potential of these forests could not be assessed in detail so far. To address this gap, several flux towers were erected over different ecosystems in India by Indian Institute of Tropical Meteorology as part of the MetFlux India project funded by MoES (Ministry of Earth Sciences, Government of India). A 50 m tall tower was set up over a semi-evergreen moist deciduous forest named Kaziranga National Park in north-eastern part of India which houses a significant stretch of local forest cover. Climatically this region is identified to be humid sub-tropical. Here we report first generation of the in situ meteorological observations and leaf area index (LAI) measurements from this site. LAI obtained from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) is compared with the in situ measured LAI. We use these in situ measurements to calculate the total gross photosynthesis (or gross primary productivity, GPP) of the forest using a calibrated model. LAI and GPP show prominent seasonal variation. LAI ranges between 0.75 in winter to 3.25 in summer. Annual GPP is estimated to be 2.11kg C m−2year−1.
• Seasonal variation of evapotranspiration and its effect on the surface energy budget closure at a tropical forest over north-east India
This study uses 1 yr of eddy covariance (EC) flux observations to investigate seasonal variations in evapotranspiration (ET) and surface energy budget (SEB) closure at a tropical semi-deciduous forest located in north-east India. The annual cycle is divided into four seasons, namely, pre-monsoon, monsoon, post-monsoon and winter. The highest energy balance closure (76%) is observed during pre-monsoon, whereas the lowest level of closure (62%) is observed during winter. Intermediate closure of 68% and 72% is observed during the monsoon and post-monsoon seasons, respectively. Maximum latent heat flux during winter (150 W m$^{-2}$) is half of the maximum latent heat (300 W m$^{-2}$) flux during the monsoon. ET is a controlling factor of SEB closure, with the highest rates of closure corresponding to the periods of the highest ET. The Bowen ratio ranges from 0.93 in winter to 0.27 during the monsoon. This is the first time the role of ET in the seasonal variation of SEB closure has been reported for any ecosystem in north-east India using EC measurements.
• # Journal of Earth System Science
Current Issue
Volume 128 | Issue 8
December 2019
• # Editorial Note on Continuous Article Publication
Posted on July 25, 2019 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5445404648780823, "perplexity": 5797.515947229965}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570987836295.98/warc/CC-MAIN-20191023201520-20191023225020-00380.warc.gz"} |
https://risk.asmedigitalcollection.asme.org/FEDSM/proceedings-abstract/FEDSM2021/85307/V003T08A005/1120962?searchresult=1 | ## Abstract
This paper numerically investigates unsteady behavior of cloud cavitation, in particular, to elucidate the induced shock wave emission. To do this, we consider a submerged water-jet injection into still water through a nozzle and make some numerical analysis of two-dimensional multiphase flows by Navier-Stokes equations. In our previous study [7], we have shown that twin vortices symmetrically appear in the injected water, which plays an essential role in performing the unsteady behavior of a cloud of bubbles. In this paper, we further illustrate the elementary process of the emission of the shock waves. First, we set up the mixture model of liquid and gas in Lagrangian description by the SPH method, together with the details on the treatment of boundary conditions. Second, we show the velocity fields of the multiphase flow to illustrate the inception, growth as well as the collapse of the cloud. In particular, we explain the mechanism of the collapse of the cloud in view of the motion of the twin vortices. Further, we investigate the pressure fields of the multiphase flow in order to demonstrate how the shock wave is emitted associated with the collapse of the cloud. Finally, we show that a small shock wave may be released prior to the main shock wave emission.
This content is only available via PDF. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8423721790313721, "perplexity": 380.3674011451146}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446711396.19/warc/CC-MAIN-20221209112528-20221209142528-00019.warc.gz"} |
http://hexloops.com/arabian-percussion-loops-arabic-percussion-samples-wav-pack?utm_source=popupfeed&utm_medium=popup&utm_campaign=livepromo | # Arabian Percussion Loops
5 out of 5 based on 1 customer rating
(1 customer review)
\$23.50
Category:
Bought by someone from US
Bought by someone from USA
Bought by someone from US
Bought by someone from USA
Bought by someone from USA
Bought by someone from USA
Bought by someone from UK
Bought by someone from US
Bought by someone from Italy
Bought by someone from UK
Bought by someone from US
Bought by someone from US
Bought by someone from US
Bought by someone from Chicago
Bought by someone from USA
Bought by someone from CA
Bought by someone from UK
Bought by someone from DE
Bought by someone from USA
Bought by someone from USA
Bought by someone from UK
Bought by someone from CA
Bought by someone from CA
Bought by someone from US
Bought by someone from New York
Bought by someone from USA
Bought by someone from Italia
Bought by someone from UK
Bought by someone from USA
Bought by someone from USA
Bought by someone from US
Bought by someone from London
Bought by someone from Spain
Bought by someone from London
Bought by someone from USA
Bought by someone from USA | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8811894655227661, "perplexity": 17453.16775291443}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218188914.50/warc/CC-MAIN-20170322212948-00205-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://physics.stackexchange.com/questions/208778/interpretation-of-the-electromagnetic-field-strength-tensor-as-a-spin-1-field | # Interpretation of the electromagnetic field strength tensor as a spin-1 field
If I understand correctly the electromagnetic field strength tensor $F_{\mu\nu}$ could be considered as a spin-1 field. In that case, what can one say about the total spin and the $z$-component of the spin for this field? Also, how is $F_{\mu\nu}$'s spin related to that of the photon field ($A_{\mu}$)?
The spin of the electromagnetic field tensor $F_{\mu\nu}$ is best understood by writing it as a spinor. A spin 1 field is a represented by a symmetric spinor $\xi^{AB}$ or by a dotted symmetric spinor $\eta_{\dot{A}\dot{B}}$. In order to get the field transforming correctly under parity, the electromagnetic field has to be a direct sum using the symmetric spinor and it's complex conjugate dotted spinor. $$F_{\mu\nu} \sim \xi^{AB}\oplus [\xi^{*}]_{\dot{A}\dot{B}}$$ The symmetric spinor $\xi^{AB}$ has three independent complex components $\xi^{11},\xi^{12}=\xi^{21},\xi^{22}$. Linear combinations of these components correspond to the three complex components of the electromagnetic field $B^{r}+iE^{r}$. The source free Maxwell equations are obtained by acting on the symmetric spinor with the Hermitian momentum operator $\hat{p}^{\dot{A}}_{\ B}$ $$\hat{p}^{\dot{A}}_{\ B}\xi^{BC}=0$$ This equation is similar to the Dirac equation for a massive spin 1/2 field. The photon is massless, so it has helicity = $\pm 1$ instead of spin (essentially spin 1 along or against the direction of flight). The photon has two helicity degrees of freedom, but the spin 1 field $F_{\mu\nu} \sim \xi^{AB}\oplus [\xi^{*}]_{\dot{A}\dot{B}}$ has six real components. The Maxwell equations $\hat{p}^{\dot{A}}_{\ B}\xi^{BC}=0$ project the spinor onto a two-dimensional subspace.
This is as far as I know how to answer the question at present. The gauge field $A^{\mu}$ is a four vector so it ought to be a Hermitian spinor field of type $X^{\dot{A}}_{\ B}$ which is the tensor product of two spin 1/2 fields. It has four components, so the gauge fixing must come in to reduce four to the two helicity degrees of freedom. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 2, "x-ck12": 0, "texerror": 0, "math_score": 0.9611865878105164, "perplexity": 158.22574813481518}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655879738.16/warc/CC-MAIN-20200702174127-20200702204127-00510.warc.gz"} |
https://socratic.org/questions/for-a-field-trip-11-students-rode-in-cars-the-rest-filled-eight-buses-how-many-s | Algebra
Topics
# For a field trip 11 students rode in cars the rest filled eight buses. How many students were in each bus if 315 students were on the trip?
Mar 4, 2018
$38$ students on each bus.
#### Explanation:
If $11$ of $315$ students were not on the buses
then $315 - 11 = 304$ students were on the buses.
If these $304$ students were divided evenly among $8$ buses
there would be $\frac{304}{8} = 38$ students on each bus.
##### Impact of this question
229 views around the world
You can reuse this answer | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 7, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9924147725105286, "perplexity": 3562.1914028212527}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-51/segments/1544376823228.36/warc/CC-MAIN-20181209232026-20181210013526-00552.warc.gz"} |
http://math.stackexchange.com/questions/134024/compact-hausdorff-space-and-continuity | # compact Hausdorff space and continuity
Let $X$ be a Hausdorff space. Suppose $f:X\rightarrow \mathbb{R}$ is such that $\{(x,f(x)):x\in X\}$ is a compact subset of $X\times \mathbb{R}$.
How would I show $f$ is continuous?
-
Show that the pre-image of a closed set under $f$ is closed (lift a closed set first to $X \times \mathbb{R}$ via the projection $X \times \mathbb{R} \to \mathbb{R}$, intersect the result with the graph and project down to $X$).
Alternatively, note that $p_X(x,f(x)) = x$ is a continuous bijection from the graph to $X$. The hypotheses imply that this is a homeomorphism. Then observe that $f = p_{\mathbb R} \circ (p_{X})^{-1}$ is a composition of continuous functions. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9699909090995789, "perplexity": 60.77216030640278}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464049274119.75/warc/CC-MAIN-20160524002114-00211-ip-10-185-217-139.ec2.internal.warc.gz"} |
https://pt.overleaf.com/blog/284-an-interview-with-overleaf-advisor-francisco-orlandini-researcher-at-labmec-state-university-of-campinas-brazil | • ## An interview with Overleaf Advisor Francisco Orlandini - researcher at LabMeC, State University of Campinas, Brazil
Posted by Shelly on January 20, 2016 "When you start using LaTeX you have the feeling that you can focus on the content of your work rather than worrying about formatting and other issues that just get in your way.Overleaf brings this feeling back." – Francisco Orlandini My name is Francisco Orlandini and I am currently pursuing my master's degree on Electrical Engineering at State University of Campinas (UNICAMP), Brazil. I study applications of the Finite Element Method in electromagnetic problems and how to implement it in an open-source object oriented finite element programming environment called NeoPZ. I also work at SimWorx, with activities regarding FEM as well. Apart from academical activities I really enjoy street photography and beat poetry. What are the biggest challenges you face in your work? To put it bluntly: To write code in a simple and efficient way. It would be really exciting to have more people using NeoPZ all over the world and I think that for it to happen the code must be as clear as possible and well-documented. Also, the mathematical aspects of the Finite Element Method can get quite confusing sometimes. But that is the fun kind of challenge, not the disappointing one. How did you first find out about Overleaf? My best friend invited me to use it. I had just begun my current job and hadn't set up LaTeX on my work computer. I decided to give it a try. It has been quite useful since then. How would you describe your experience of using Overleaf? I use it practically everyday at university, at home and at work. When on a heavier project (a long beamer presentation, for instance) I usually use the github integration for a faster compilation at my computer. I really enjoy its autocomplete feature: I think it is really helpful for someone that isn't used to LaTeX - Let's say it can make the first contact less scary (and it is also brilliant for those days when you are tired and your memory seems to have taken a break from work). With no set up needed, it is quite convenient for university group projects as well. What's next for you and your work? I wish I knew! In summary, how would you describe Overleaf in one sentence? When you start using LaTeX you have the feeling that you can focus on the content of your work rather than worrying about formatting and other issues that just get in your way. Overleaf brings this feeling back. Thanks Francisco! Good luck with your master's degree and in your work on NeoPZ and SimWorx.If you're interested in becoming an Overleaf Advisor like Francisco, you can find out more and apply here!
Tags: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 1, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.25807493925094604, "perplexity": 924.5622335488642}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540517557.43/warc/CC-MAIN-20191209041847-20191209065847-00137.warc.gz"} |
https://inordinatum.wordpress.com/2012/07/29/directed-polymers/ | # inordinatum
Physics and Mathematics of Disordered Systems
## A very brief introduction to directed polymers
A classical problem in the field of disordered systems is an elastic string (or elastic polymer) stretched between two points in a random environment. One is interested in knowing how the polymer geometry (roughness), ground state energy, and excitations change due to the disordered environment. A fundamental question is if the polymer becomes rough for arbitrarily weak disorder, or if there is a phase transition between a weakly disordered (smooth) and a strongly disordered (rough) phase.
In the following I will try explain some basic results on the simple case of a two-dimensional directed polymer (i.e. a “stretched” polymer which does not contain loops or overhangs). I will explain why for large polymer lengths $L$, moments of the partition sum $Z$ grow as $\ln \overline{Z^n} \propto n^3 L$. I will show why this indicates a rough polymer with roughness exponent $\zeta=\frac{2}{3}$. This analysis holds for arbitrarily weak disorder, meaning that in two dimensions disorder is always relevant, and the polymer is always in the rough phase.
Although none of these observations are new, the existing results are often buried in technical literature (there is not even a Wikipedia page describing the directed polymer problem). I hope this self-contained summary will be useful for people interested in a quick introduction to the subject. Some original references where more details can be found are cited at the end of the post.
## The directed polymer partition sum, and its moments
We can consider a polymer configuration as a trajectory for a particle moving between two points. We call the polymer directed if the particle always moves from the initial towards the final point, i.e. if the trajectory does not contain loops or overhangs.
Formally, this means that the polymer configuration in $1+d$ dimensions can be parametrized by giving $d$ transversal coordinates $(x_1...x_d)=\vec{x}$ as a function of the longitudinal coordinate $t$ (distance along the path). The partition sum is then given by a path integral
$Z = \int \mathcal{D}[\vec{x}]e^{-\int_0^L \mathrm{d}t \, \left[(\dot{\vec{x}})^2 + \eta(\vec{x},t)\right]}$
$(\dot{\vec{x}})^2$ is the elastic energy term, which is minimized for straight paths. $\eta(\vec{x},t)$ is the energy it costs the polymer to pass through the site $(\vec{x},t)$ (and which is minimized for rough paths picking out the minimal energy sites). We model a disordered environment by taking $\eta$ to be uncorrelated Gaussian white noise:
$\displaystyle \overline{\eta(\vec{x}_1,t_1)\eta(\vec{x}_2,t_2)} = 2c\delta^{(d)}(\vec{x}_1-\vec{x}_2)\delta(t_1-t_2)$
Applying the Feynman-Kac formula, the partition sum $Z(\vec{x},t)$ satisfies the following stochastic differential equation:
$\displaystyle \partial_t Z(\vec{x},t) = \nabla^2 Z(\vec{x},t) +\eta(\vec{x},t) Z(\vec{x},t)$
$Z$ is a random quantity, because $\eta$ is random. Since computing the distribution of $Z$ is difficult, we will consider its moments, defined as
$\displaystyle \Psi_n(\vec{x}_1...\vec{x}_n,t) := \overline{Z(\vec{x}_1,t)\cdots Z(\vec{x}_n,t)}$
The time evolution of $\Psi_n$ is determined by applying the Itô formula to the equation for $Z$:
$\displaystyle \partial_t\Psi_n(\vec{x}_1...\vec{x}_n,t) = \left[\sum_{j=1}^n \nabla_{\vec{x}_j}^2 + 2c\sum_{j
This is, up to an overall sign, the Schrödinger equation for $n$ bosons interacting through pairwise pointlike attraction of strength $c$. In one dimension, this is called the Lieb-Liniger model. It is easy to determine the ground state of this system exactly, which will allow us to obtain the leading behaviour of $Z^n$ for large $t$.
## Solution in one spatial dimension: Bethe ansatz ground state
In $d=1$, the ground state of the Hamiltonian $H_n$ defined above has energy $E_n = \frac{c^2}{12}n(n^2-1)$ and is given by
$\displaystyle \Psi_n(\vec{x}_1...\vec{x}_n) \propto \exp\left(-\frac{c}{2}\sum_{j
This is a special case of the general Bethe ansatz ubiquitious in modern theoretical physics. Its application to the directed polymer problem, as discussed here, was recognized by Kardar (see references below).
To check that this ansatz for $\Psi$ gives, indeed, an eigenstate, let us take two derivatives with respect to $x_j$:
$\displaystyle \begin{array}{lcl} \partial_{x_j}^2 \Psi_n & = & \partial_{x_j} \left[-\frac{c}{2}\sum_{j \neq k} \text{sgn}(x_j-x_k) \Psi_n\right] \\ & = & \left[-c\sum_{j \neq k} \delta(x_j-x_k)\right] \Psi_n + \left[-\frac{c}{2}\sum_{k \neq j} \text{sgn}(x_j-x_k)\right]^2 \Psi_n \end{array}$
Taking the sum over all $j$ we get
$\displaystyle \sum_{j=1}^n \partial_{x_j}^2 \Psi_n = -2c\sum_{j < k} \delta(x_j-x_k) \Psi_n + \frac{c^2}{4}\sum_{j=1}^n \left[\sum_{j \neq k} \text{sgn}(x_j-x_k)\right]^2 \Psi_n$
To compute the second term, note that it is symmetric under permutations of the $x_j$. Let us assume (without loss of generality) that $x_1 < x_2 < ... < x_n$. Then
$\displaystyle \begin{array}{lcl} \sum_{j=1}^n \left[\sum_{j \neq k} \text{sgn}(x_j-x_k)\right]^2 & = & \sum_{j=1}^n \left[\sum_{k>j} (-1)+\sum_{k
Thus, we see that as claimed,
$\displaystyle H_n \Psi_n = E_n \Psi_n$
with the energy $E_n = \frac{c^2}{12}n(n^2-1)$. To see that this is, indeed, the ground state, is beyond the scope of this post (essentially it would require one to take a finite system volume $V$, construct all excited states using the Bethe ansatz, and check that they all have higher energy. Since one knows the number of eigenstates in a finite volume, this would exclude any lower-energy state).
Believing that this is, indeed, the ground state our argument shows that for large polymer length $L$, the moments of the partition sum $Z$ grow as:
$\displaystyle \overline{Z^n (L)} \propto e^{\frac{c^2}{12}n(n^2-1) L}$
## Implications for the string geometry
The asymptotics of $\overline{Z^n}$ derived above is consistent with a free energy that scales with polymer length $L$ as $\ln Z = F =: f L^\frac{1}{3}$. Furthermore, the distribution $P(f)$ of the rescaled free energy should have a tail decaying as
$\displaystyle P(f) \propto e^{-f^{\frac{3}{2}}} \quad \text{for } f \gg 1$
To see this, let us compute $\overline{Z^n}$ assuming this form for $P(f)$:
$\displaystyle \overline{Z^n} = \int \mathrm{d}f e^{n f L^{\frac{1}{3}}-f^{\frac{3}{2}}}$
For large $n$, we expect $f$ to be large; thus the integral can be approximated by the maximum of the exponent. It occurs at
$f \propto \left(n L^{\frac{1}{3}}\right)^2$
and thus we get
$\displaystyle \ln \overline{Z^n} \propto L n^3$,
consistent with the large-$n$ behaviour of the explicit formula for $\overline{Z^n}$ derived above.
Thus, the asymptotics of $\overline{Z^n}$ allowed us to determine the tail of the free energy distribution $P(f)$ and the scaling $F = f L^\frac{1}{3}$. The scaling of the typical displacement $x$ with polymer length $L$ follows:
$\displaystyle L^\frac{1}{3} \sim F \sim \int_0^L \mathrm{d}t (\dot{x})^2 \sim L \left(\frac{x}{L}\right)^2 \Rightarrow x \sim L^\frac{2}{3}$
Thus, the polymer is rough in the sense that the typical fluctuations don’t remain bounded, but increase with polymer length as
$\displaystyle \overline{\left[x(L)-x(0)\right]^2}\sim L^{2\zeta}$
with the so-called roughness exponent $\zeta= \frac{2}{3}$.
This whole analysis remains valid at an arbitrarily weak coupling strength $c$. Thus, the polymer is rough for arbitrarily weak disorder (or, equivalently, arbitrarily high temperatures). In order to observe a true phase transition between weak-disorder and strong-disorder behaviour one needs to go to higher dimensions.
## Higher dimensions and phase transitions
As we have now seen, in two dimensions (one longitudinal + one transversal) the directed polymer is always in a rough phase. It turns out (but it would take too long to explain here) that the same holds in three (1+2) dimensions. However, starting from one longitudinal + three transversal dimensions, weak disorder is insufficient to make the polymer rough. In other words, there is a high-temperature phase where the moments of $Z$ scale as $\ln \overline{Z^n} \propto n^2$, indicating Gaussian fluctuations, i.e. purely thermal roughness.
## References
The original argument for obtaining the moments of $Z$ from the Bethe ansatz solution of the Lieb-Liniger model is due to Kardar (see e.g. Nucl. Phys. B 290, 1989 and the references therein). The saddle-point argument for the tail of the free energy distribution is due to Zhang (see e.g. PRB 42, 1990). If you feel some other reference should be included please let me know!
Written by inordinatum
July 29, 2012 at 9:42 pm
### 10 Responses
1. […] few posts ago I briefly talked about the problem of a directed polymer in a random medium. In that post, I discussed the scaling behaviour of the polymer fluctuations due to the disordered […]
2. A time derivative, $\partial_t \Psi_n$, seems to be missing in front of the evolution equation for $\Psi$, the Schrodinger equation. Great web notes, congratulations!
Juan M Lopez
September 16, 2016 at 3:45 pm
• Thanks, I just corrected that! Glad you enjoyed it 🙂
inordinatum
September 17, 2016 at 9:34 am
3. […] a cartesian lattice in 1+1 dimensions, the roughness exponent is known exactly (see e.g. my earlier introduction to directed polymers) and, in some cases, even the distribution of the free energy can be computed (see my earlier post […]
4. Great Introduction again!
I missed exactly how one gets the ground energy value. Is their a simple counting argument?
Thanks a lot
GUILLAUME A
January 31, 2018 at 4:27 pm
• Thanks!
The ground energy value is calculated in section “Solution in one spatial dimension: Bethe ansatz ground state” – the calculations there show that when you apply the Hamiltonian (including the Laplacian and the delta-functions sum) to the wave function $\Psi_n$ you obtain again $\Psi_n$, multiplied by $E_n$… Let me know if something is unclear there!
inordinatum
February 3, 2018 at 4:03 pm
• Oh yes you are right! I was wondering how does one finds the eigen vectors/values together by some general method… but of course it is all enclosed in the Bethe ansatz itself ! My bad, I never learned that properly, now I know at least that bit 😉
Thanks again!
GUILLAUME A
February 3, 2018 at 7:00 pm
• Let me try to ask a more ‘clever’ question this time:
So as it looks, Bethe ansatz works pretty well for delta correlated potentials, I guess we can work out generalizations ? And as a corollary, could you indicate maybe a few cases where the roughness exponent is modified in specific ways ? I am interested to delve deeper into it.
Again : Great blog!
GUILLAUME A
February 3, 2018 at 7:18 pm
• Thanks 🙂
The roughness exponent is actually pretty robust, on large scales it appears independently of the small-scale details of the system. I.e., even if you smoothen the delta-correlated potential slightly, or add small thermal fluctuations, it will remain the same.
A different roughness exponent is obtained if you modify the universality class of your model, e.g. by changing the spatial dimension or by introducing long-range correlations (e.g. long-range elastic coupling or long-range correlated disorder). See e.g. the following papers and the references therein:
– Peng, Havlin, Schwartz, Eugene Stanley 1991, “Directed-polymer and ballistic-deposition growth with correlated noise”, available on ResearchGate
– Rosso, Krauth 2002, “Roughness at the depinning threshold for a long-range elastic string”, arXiv: cond-mat/0107527
– Fedorenko, Le Doussal, Wiese 2006, “Statics and dynamics of elastic manifolds in media with long-range correlated disorder”, arxiv:cond-mat/0609234
inordinatum
February 5, 2018 at 9:16 pm
• Fascinating!
GUILLAUME A
February 6, 2018 at 10:04 am | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 76, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9383302330970764, "perplexity": 1132.218997098604}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257647406.46/warc/CC-MAIN-20180320111412-20180320131412-00768.warc.gz"} |
https://mathoverflow.net/questions/380008/a-p-adic-logarithm-as-a-limit-of-discrete-logs | # A p-adic logarithm as a limit of discrete logs
I've been searching for something similar to the argument below for about a week now and I just must be missing out on the right key words. Can someone point me in the right direction and/or let me know where I'm going wrong? I haven't worked out the details yet; spending most of my time trying to find the article where someone must've worked through all this before...
Let $$p$$ be an odd prime. Let $$g$$ be a primitive root mod $$p^n$$ for all $$n \ge 2$$. Then for any $$a \in \mathbb{Z}$$ relatively prime to $$p$$, we can define the index $$\text{ind}_{(g,n)}(a) = k_n$$ where $$g^{k_n} \equiv a \mod p^n$$. Such $$k_n$$ are only defined modulo $$\phi(p^n) = (p-1)p^{n-1}$$. But it also must be true that $$k_n \equiv k_{n-1} \mod (p-1)p^{n-2}$$. Thus for some $$0 \le c_i \le p$$ and $$0\le c_0 \le p-1$$, $$k_n \equiv c_0 + c_1(p-1)+c_2(p-1)p+c_3(p-1)p^2+\cdots+c_{n-1}(p-1)p^{n-2} \mod (p-1)p^{n-1}.$$ Hence $$\{k_n\}$$ converges $$p$$-adically to some $$k \in \mathbb{Q}_p$$. Define $$\text{ind}_g(a)=k$$. Seems reasonable to believe then that $$g^k = a$$ in $$\mathbb{Q}_p$$.
Questions:
• Initially the domain is integers relatively prime to $$p$$. It seems like these methods can be extended to $$z \in \mathbb{Q}$$ with $$|z|_p = 1$$ (for $$z=\frac{a}{b}$$, just use $$ab^{-1}$$ computed mod $$p^n$$). So perhaps it can be defined on any unit of $$\mathbb{Q}_p$$?
• How does this relate (if at all) to the $$p$$-adic logarithm that shows up in all my internet searches? It seems that $$\text{ind}_g$$ is defined on the boundary of the domain of $$\log_p$$.
For $$p\ge 3$$ if $$g$$ is a generator of $$(\Bbb{Z}/(p^2))^\times$$ then it is a generator of all $$(\Bbb{Z}/(p^k))^\times$$. For $$a\in \Bbb{Z}_p^\times$$ there is a unique $$l_{g,k}(a)\in \Bbb{Z}/(p-1)p^{k-1}\Bbb{Z}$$ such that $$a= g^{l_{g,k}(a)}\bmod p^k$$.
For $$m, $$l_{g,k}(a)= l_{g,m}(a) \bmod (p-1)p^{m-1}$$ thus $$l_{g,k}(a)= l_{g,m}(a) \bmod p^{m-1}$$ and hence $$l_g(a)=\lim_{k\to \infty}l_{g,k}(a)$$ converges in $$\Bbb{Z}_p$$ and $$a=\lim_{k\to \infty} g^{l_{g,k}(a)}$$.
Let $$c_k\in 0\ldots p^{k-1}-1,c_k = l_{g,k}(a)\bmod p^{k-1}$$. Then $$a=\lim_{k\to \infty} g^{c_k}$$ iff $$a=1\bmod p$$. In other words the full discrete logarithm of a $$p$$-adic number is an element of $$\Bbb{Z}/(p-1) \times \Bbb{Z}_p$$ and when keeping only the $$\Bbb{Z}_p$$ part we lose the $$a\bmod p$$ information.
If $$c\in 1+p\Bbb{Z}_p$$ then $$l_g(c) = \frac{\log_p(c)}{\log_p(g^{p-1})}\in \Bbb{Z}_p$$ where $$\log_p$$ is the $$p$$-adic logarithm $$\log_p(1+pb)=\sum_{n\ge 1}\frac{p^n(-1)^{n-1} b^n}{n}, b\in \Bbb{Z}_p$$
For $$a,a'\in \Bbb{Z}_p^\times$$, $$l_g(a)=l_g(a')\in \Bbb{Z}_p$$ iff $$a/a'$$ has finite order in $$\Bbb{Z}_p^\times$$ iff $$a^{p-1}=(a')^{p-1}$$.
$$\log_p(g^{p-1})\ne 1$$ when $$g$$ is an integer. $$\log_p(1+pb)=1$$ iff $$1+pb=\sum_{n\ge 0}\frac{p^n b^n}{n!}=\exp_p(1)$$ which is not in $$\Bbb{Q}\cap \Bbb{Z}_p$$.
$$\log_p$$ is the discrete logarithm in base $$\exp_p(1)$$, ie. $$\log_p(1+pb)= \lim_{k\to \infty} l_{\exp_p(1)\bmod p^k,k}(1+pb)$$.
• This is great stuff. Is there a resource (book, article, etc.) that gives more detail? Or is this just, as my advisor used to say, known by those who know things? Jan 2, 2021 at 19:28
• Also, this doesn't answer the question of if the $k_n$ as constructed work. The $k_n$ explicitly contain the $\mathbb{Z}/(p-1)$ information. So we should be able to retain $a \mod p$. Mar 20 at 17:30
For whatever it's worth, below is a paper of mine that discusses lifting the elliptic curve discrete log in $$E(\mathbb F_p$$) to $$E(\mathbb Z/p^2\mathbb Z)$$ and eventually to $$E(\mathbb Z_p)$$. It gives two methods, neither of which allows one to solve the ECDLP, but they fail for somewhat different reasons, which I always found kind of interesting. BTW, you might want to add a cryptography tag to your question, since clearly it's very relevant there.
Again talking about elliptic curves, in the case the $$\#E(\mathbb F_p)=p$$, then in fact this sort of lifting procedure does work, because you can (more-or-less) multiply the point by $$p$$ to get into the formal group while maintaining the order coming from the mod $$p$$ point. That's the only situation that I know of where such a lifting works. I mention it because in some sense it shows what goes wrong in the classical $$\mathbb F_p$$ case, namely the order of the group $$\mathbb F_p^*$$ is $$p-1$$, which is not a multiple of $$p$$.
Lifting and Elliptic Curve Discrete Logarithms, Conference: Selected Areas in Cryptography, 15th International Workshop, SAC 2008, Sackville, New Brunswick, Canada, August 14-15,
DOI: 10.1007/978-3-642-04159-4_6 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 78, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9858222007751465, "perplexity": 572.360055208107}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296949701.56/warc/CC-MAIN-20230401063607-20230401093607-00497.warc.gz"} |
http://gdaymath.com/lessons/fractions/3-5-percentages/ | ## Fractions are Hard!
### 3.5 Percentages
In the first century B.C.E., Roman Emperor Augustus levied for the first time a tax of one part per hundred on the proceeds of all goods sold at markets and auctions in ancient Rome. From the Latin phrase per centum meaning “by the hundred” came the term percent.
A percent is just a fraction with denominator one hundred (the number of pies per 100 boys). For example, $$\dfrac{1}{2}$$ written as a fraction with denominator one hundred is
$$\dfrac{1}{2}=\dfrac{1\times 50}{2\times 50}=\dfrac{50}{100}$$.
We say that $$\dfrac{1}{2}$$ equals 50 percent, and write
$$\dfrac{1}{2}=50\%$$.
Levying a tax of 1 dollar for every 100 dollars results in $$\dfrac{1}{100}$$, one one-hundredth, of all cash exchanged being given to the government. This is tax rate of $$1\%$$.
The symbol $$\%$$ developed in Italy during the 1500s. Clerks started shortening per cento to P 00, which then eventually became $$%$$.
Working backwards is actually easier. For example, 80% is a fraction with denominator 100. We have
$$80\%=\dfrac{80}{100}$$
which is equivalent to the fraction $$\dfrac{4}{5}$$.
Some more examples:
$$\dfrac{3}{10}=\dfrac{30}{100}=100\%$$
$$2 = \dfrac{200}{100}=200\%$$
$$0.632=\dfrac{0.632}{1}=\dfrac{0.632\times 100}{1 \times 100}=\dfrac{63.2}{100}=63.2\%$$
Question: Nervous Nelly wants a rule for understanding percentages. Someone once told her that to write a number $$x$$ as a percentage, just multiply that number by 100 and write a $$\%$$ sign after the result. For example: $$\dfrac{1}{2}\times 100 = 50$$ and indeed $$\dfrac{1}{2}$$ is $$50\%$$. $$0.632\times 100 = 63.2$$ and indeed $$0.632$$ is $$63.2\%$$. $$\dfrac{3}{7}\times 100 = \dfrac{300}{7}=42\dfrac{6}{7}$$ and indeed $$\dfrac{3}{27}$$ is $$42\dfrac{6}{7}\%$$. One day, maybe in the distant future, Nervous Nelly will ask why this rule works. What would you say to her? How would you explain why this rule is true? (And did she even need to memorize this as rule in the first place?)
And backwards
$$53\% = \dfrac{53}{100}$$
$$25\% = \dfrac{25}{100}=\dfrac{1}{4}$$
$$150\% = \dfrac{150}{100}=1\dfrac{1}{2}$$
$$1000\% = \dfrac{1000}{100}=10$$
Question: The price of a Nice-and-Spicy Soup Cup yesterday was $1.50. It’s price went up to$1.80 overnight. What percentage increase is that?
Question: The ancient Romans also spoke of parts per thousand. Today this is called, if it is ever used, per millage with the symbol o/oo. For example, 467 o/oo equals $$\dfrac{467}{1000}$$, and one tenth, which is $$\dfrac{1}{10} = \dfrac{100}{1000}$$, equals $$100$$ o/oo. Convert each of these per millages into fractions a) 40 o/oo b) 500 o/oo c) 6000 o/oo d) 2 o/oo Convert each of the following fractions into per millages: a) $$\dfrac{1}{100}$$ b) $$\dfrac{2}{5}$$ c) $$30\%$$ d) $$1$$ e) $$0$$
## Books
Take your understanding to the next level with easy to understand books by James Tanton.
BROWSE BOOKS
## Guides & Solutions
Dive deeper into key topics through detailed, easy to follow guides and solution sets.
BROWSE GUIDES
## Donations
Consider supporting G'Day Math! with a donation, of any amount.
Your support is so much appreciated and enables the continued creation of great course content. Thanks!
Donations can be made via PayPal and major credit cards. A PayPal account is not required. Many thanks!
DONATE | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8040818572044373, "perplexity": 3701.760488930401}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-30/segments/1500549424088.27/warc/CC-MAIN-20170722162708-20170722182708-00120.warc.gz"} |
https://paperswithcode.com/paper/on-the-power-of-adaptivity-in-matrix | # On the Power of Adaptivity in Matrix Completion and Approximation
14 Jul 2014
We consider the related tasks of matrix completion and matrix approximation from missing data and propose adaptive sampling procedures for both problems. We show that adaptive sampling allows one to eliminate standard incoherence assumptions on the matrix row space that are necessary for passive sampling procedures... (read more)
PDF Abstract
# Code Edit Add Remove Mark official
No code implementations yet. Submit your code now | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8926270604133606, "perplexity": 2267.615284010358}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141733120.84/warc/CC-MAIN-20201204010410-20201204040410-00260.warc.gz"} |
https://rd.springer.com/article/10.1007%2Fs10479-018-2990-0 | Annals of Operations Research
, Volume 273, Issue 1–2, pp 279–310
# Traffic equilibrium with a continuously distributed bound on travel weights: the rise of range anxiety and mental account
• Chi Xie
• Xing Wu
• Stephen Boyles
S.I.: OR in Transportation
## Abstract
A new traffic network equilibrium problem with continuously distributed bounds on path weights is introduced in this paper, as an emerging modeling tool for evaluating traffic networks in which the route choice behavior of individual motorists is subject to some physical or psychological upper limit of a travel weight. Such a problem may arise from at least two traffic network instances. First, in a traffic network serving electric vehicles, the driving range of these vehicles is subject to a distance constraint formed by onboard battery capacities and electricity consumption rates as well as network-wide battery-recharging opportunities, which cause the range anxiety issue in the driving population. Second, in a tolled traffic network, while drivers take into account both travel time and road toll in their route choice decisions, many of them implicitly or explicitly set a budget constraint in their mental account for toll expense, subject to their own income levels and other personal and household socio-economic factors. In both cases, we model the upper limit of the path travel weight (i.e., distance or toll) as a continuously distributed stochastic parameter across the driving population, to reflect the diverse heterogeneity of vehicle- and/or motorist-related travel characteristics. For characterizing this weight-constrained network equilibrium problem, we proposed a convex programming model with a finite number of constraints, on the basis of a newly introduced path flow variable named interval path flow rate. We also analyzed the problem’s optimality conditions for the case of path distance limits, and studied the existence of optimal tolls for the case of path toll limits. A linear approximation algorithm was further developed for this complex network equilibrium problem, which encapsulates an efficient weight-constrained k-minimum time path search procedure to perform the network loading. Numerical results obtained from conducting quantitative analyses on example networks clearly illustrate the applicability of the modeling and solution methods for the proposed problem and reveal the mechanism of stochastic weight limits reshaping the network equilibrium.
## Keywords
Traffic assignment with side constraints Network equilibrium Stochastic weight limit Electric vehicles Range anxiety Road tolls Mental account
## Notes
### Acknowledgements
The authors greatly benefited in the review process from the comments offered by the editors and four anonymous referees. This study is jointly supported by research grants through the Young Talent Award from the China Recruitment Program of Global Experts, the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 2013-007312-0069), the National Natural Science Foundation of China (Grant No. 71471111, 71771150), the Science and Technology Commission of the Shanghai Municipality (Grant No. 17692108500). This research was also partially supported by the U.S. National Science Foundation (Grant No. CMMI-1254921, CMMI-1562291) and the Data-Supported Transportation Operations and Planning Center.
## References
1. Arezki, Y., & Van Vliet, D. (1990). A full analytical implementation of the PARTAN Frank–Wolfe algorithm for equilibrium assignment. Transportation Science, 24(1), 58–62.Google Scholar
2. Bahrami, S., Asshtiani, H. Z., Nourinejad, M., & Roorda, M. J. (2017). A complementarity equilibrium model for electric vehicles with charging. International Journal of Transportation Science and Technology, 6(4), 255–271.Google Scholar
3. Ban, X. J., Ferris, M. C., Tang, L., & Lu, S. (2013). Risk-neutral second best toll pricing. Transportation Research Part B, 48, 67–87.Google Scholar
4. Batarce, M., & Ivaldi, M. (2014). Urban travel demand model with endogenous congestion. Transportation Research Part A, 59, 331–345.Google Scholar
5. Beckmann, M. J., McGuire, C. B., & Winsten, C. B. (1956). Studies in the economics of transportation. New Haven, CT: Yale University Press.Google Scholar
6. Brotcorne, L., Labbe, M., Marcotte, P., & Savard, G. (2001). A bilevel model for toll optimization on a multicommodity transportation network. Transportation Science, 35(4), 345–358.Google Scholar
7. Cheng, L., Yasunori, I., Nobuhiro, U., & Wang, W. (2003). Alternative quasi-Newton methods for capacitated user equilibrium assignment. Transportation Research Record, 1857, 109–116.Google Scholar
8. Daganzo, C. F. (1977a). On the traffic assignment problem with flow dependent costs—I. Transportation Research, 11(6), 433–437.Google Scholar
9. Daganzo, C. F. (1977b). On the traffic assignment problem with flow dependent costs—II. Transportation Research, 11(6), 439–441.Google Scholar
10. Dial, R. B. (1979). A probabilistic multipath traffic assignment problem which obviates path numeration. Transportation Research, 5(2), 83–111.Google Scholar
11. Dial, R. B. (1996). Bicriterion traffic assignment: Basic theory and elementary algorithms. Transportation Science, 30(2), 93–111.Google Scholar
12. Dial, R. B. (1997). Bicriterion traffic assignment: Efficient algorithms plus examples. Transportation Research Part B, 31(5), 357–379.Google Scholar
13. Dial, R. B. (1999a). Network-optimized road pricing: Part I: A parable and a model. Operations Research, 47(1), 54–64.Google Scholar
14. Dial, R. B. (1999b). Network-optimized road pricing: Part II: Algorithms and examples. Operations Research, 47(2), 327–336.Google Scholar
15. Florian, M., Constantin, I., & Florian, D. (2009). A new look at projected gradient method for equilibrium assignment. Transportation Research Record, 2090, 10–16.Google Scholar
16. Florian, M., Guelat, J., & Spiess, H. (1987). An efficient implementation of the “PARTAN” variant of the linear approximation method for the network equilibrium problem. Networks, 17(3), 319–339.Google Scholar
17. Frank, M., & Wolfe, P. (1956). An algorithm for quadratic programming. Naval Research Logistics Quarterly, 3(1–2), 95–110.Google Scholar
18. Franke, T., & Krems, J. F. (2013). What drives range preferences in electric vehicle users? Transport Policy, 30, 56–62.Google Scholar
19. Gabriel, S. A., & Bernstein, D. (1997). The traffic equilibrium problem with nonadditive path costs. Transportation Science, 31(4), 337–348.Google Scholar
20. Goodwin, P. B. (1981). The usefulness of travel budgets. Transportation Research Part A, 15(1), 97–106.Google Scholar
21. Gulipalli, S., & Kockelman, K. M. (2008). Credit-based congestion pricing: A Dallas–Fort Worth application. Transport Policy, 15(1), 23–32.Google Scholar
22. He, F., Yin, Y., & Lawphongpanich, S. (2014). Network equilibrium models with battery electric vehicles. Transportation Research Part B, 67, 306–319.Google Scholar
23. Hearn, D. W. (1980). Bounding flows in traffic assignment models, research report 80-4. Gainesville, FL: Department of Industrial and Systems Engineering, University of Florida.Google Scholar
24. Himanen, V., Lee-Gosselin, M., & Perrels, A. (2005). Sustainability and the interactions between external effects of transport. Journal of Transport Geography, 13(1), 23–28.Google Scholar
25. Holmberg, K., & Yuan, D. (2003). A multicommodity network flow problem with side constraints on paths solved by column generation. INFORMS Journal on Computing, 15(1), 42–57.Google Scholar
26. Jahn, O., Möhring, R. H., Schulz, A. S., & Stier-Moses, N. E. (2005). System-optimal routing of traffic flows with user constraints in networks with congestion. Operations Research, 53(4), 600–616.Google Scholar
27. Jiang, N., & Xie, C. (2014). Computing and analyzing mixed equilibrium network flows with gasoline and electric vehicles. Computer-Aided Civil and Infrastructure Engineering, 29(8), 626–641.Google Scholar
28. Jiang, N., Xie, C., Duthie, J. C., & Waller, S. T. (2013). A network equilibrium analysis on destination, route and parking choices with mixed gasoline and electric vehicular flows. EURO Journal on Transportation and Logistics, 3(1), 55–92.Google Scholar
29. Jiang, N., Xie, C., & Waller, S. T. (2012). Path-constrained traffic assignment: Model and algorithm. Transportation Research Record, 2283, 25–33.Google Scholar
30. Kitamura, R., & Lam, T. N. (1984). A model of constrained binary choice. In Proceedings of the 9th international symposium on transportation and traffic theory, Delft, July 11–13, 1984.Google Scholar
31. Larsson, T., & Patriksson, M. (1995). An augmented Lagrangean dual algorithm for link capacity side constrained traffic assignment problems. Transportation Research Part B, 29(6), 433–455.Google Scholar
32. Larsson, T., & Patriksson, M. (1999). Side constrained traffic equilibrium models—analysis, computation and applications. Transportation Research Part B, 33(4), 233–264.Google Scholar
33. Lawler, E. L. (1976). Combinatorial optimization: Networks and matroids, holt. New York, NY: Rinehart & Winston.Google Scholar
34. LeBlanc, L. J., Helgason, R. V., & Boyce, D. E. (1985). Improved efficiency of the Frank–Wolfe algorithm for convex network programs. Transportation Science, 19(4), 445–462.Google Scholar
35. Leurent, F. (1993). Cost versus time equilibrium over a network. European Journal of Operational Research, 71(2), 205–221.Google Scholar
36. Lin, Z. (2014). Optimizing and diversifying electric vehicle driving range for U.S. drivers. Transportation Science, 48(4), 635–650.Google Scholar
37. Lo, H. K., & Chen, A. (2000). Traffic equilibrium problem with route-specific costs: Formulation and algorithms. Transportation Research Part B, 34(6), 493–513.Google Scholar
38. Marcotte, P., & Zhu, D. L. (2009). Existence and computation of optimal tolls in multiclass network equilibrium problems. Operations Research Letters, 27(3), 211–214.Google Scholar
39. Marrow, K., Karner, D., & Francfort, J. (2008). Plug-in hybrid electric vehicle charging infrastructure review. In Report INL/EXT-08-15058, U.S. Department of Energy, Washington, DC.Google Scholar
40. Mock, P., Schmid, S., & Friendrich, H. (2010). Market prospects of electric passenger vehicles. In G. Pistoria (Ed.), Electric and hybrid vehicles: Power sources, models, sustainability, infrastructure and the market. Amsterdam: Elsevier.Google Scholar
41. Mokhtarian, P. L., & Chen, C. (2004). TTB or not TTB, that is the question: A review and analysis of the empirical literature on travel time and money budgets. Transportation Research Part A, 38(9–10), 643–675.Google Scholar
42. Nie, Y., Zhang, H. M., & Lee, D. H. (2004). Models and algorithms for the traffic assignment problem with link capacity constraints. Transportation Research Part B, 38(4), 285–312.Google Scholar
43. Raith, A., Wang, J. Y. T., Ehrgott, M., & Mitchell, S. (2014). Solving multi-objective traffic assignment. Annals of Operations Research, 222(1), 483–516.Google Scholar
44. Schulz, A. S., & Stier-Moses, N. E. (2006). Efficiency and fairness of system-optimal routing with user constraints. Networks, 48(4), 223–234.Google Scholar
45. Thaler, R. H. (1985). Mental accounting and consumer choice. Marketing Science, 4(3), 199–214.Google Scholar
46. Thaler, R. H. (1990). Anomalies: Saving, fungibility, and mental accounts. Journal of Economic Perspectives, 4(1), 193–205.Google Scholar
47. Thaler, R. H. (1999). Mental accounting matters. Journal of Behavioral Decision Making, 12(3), 183–206.Google Scholar
48. Verhoef, E. (2002a). Second-best congestion pricing in general networks: Heuristic algorithms for finding second-best optimal toll levels and toll points. Transportation Research Part B, 36(8), 707–729.Google Scholar
49. Verhoef, E. (2002b). Second-best congestion pricing in general static transportation networks with elastic demands. Regional Science and Urban Economics, 32(3), 281–310.Google Scholar
50. Wang, J. Y. T., & Ehrgott, M. (2013). Modeling route choice behavior in a tolled road network with a time surplus maximization bi-objective user equilibrium model. Transportation Research Part B, 57, 342–360.Google Scholar
51. Wang, L., Lin, A., & Chen, Y. (2010a). Potential impact of recharging plug-in hybrid electric vehicles on locational marginal prices. Naval Research Logistics, 57(8), 686–700.Google Scholar
52. Wang, J. Y. T., Raith, A., & Ehrgott, M. (2010b). Tolling analysis with bi-objective traffic assignment. In M. Ehrgott, B. Naujoks, T. Stewart, & J. Wallenius (Eds.), Multiple criteria decision making for sustainable energy and transportation systems. Berlin: Springer.Google Scholar
53. Wang, T. G., Xie, C., Xie, J., & Waller, S. T. (2016). Path-constrained traffic assignment: A trip chain analysis under range anxiety. Transportation Research Part C, 68, 447–461.Google Scholar
54. Xie, C., & Jiang, N. (2016). Relay requirement and traffic assignment of electric vehicles. Computer-Aided Civil and Infrastructure Engineering, 31(8), 580–598.Google Scholar
55. Xie, C., Wang, T. G., Pu, X., & Karoonsoontawong, A. (2017). Path-constrained traffic assignment: Modeling and computing network impacts of stochastic range anxiety. Transportation Research Part B, 103, 136–157.Google Scholar
56. Yang, H., & Huang, H. J. (2004). The multi-class, multi-criteria traffic network equilibrium and systems optimum problem. Transportation Research Part B, 28(1), 1–15.Google Scholar
57. Yang, H., Wang, X., & Yin, Y. (2012). The impact of speed limits on traffic equilibrium and system performance in networks. Transportation Research Part B, 46(10), 1295–1307.Google Scholar
58. Yang, H., & Wong, S. C. (1999). Estimation of the most likely equilibrium traffic queueing pattern in a capacity-constrained network. Annals of Operations Research, 87, 73–85.Google Scholar
59. Yen, J. Y. (1971). Finding the k shortest loopless paths in a network. Management Science, 17(11), 712–716.Google Scholar
60. Zahavi, Y. (1979). UMOT project. In Report DOT-RSPA-DPB-20-79-3, U.S. Department of Transportation, Washington, DC.Google Scholar
61. Zahavi, Y., & Ryan, J. M. (1980). Stability of travel components over time. Transportation Research Record, 750, 13–19.Google Scholar
62. Zhang, H., & Ge, Y. (2004). Modeling variable demand equilibrium under second-best road pricing. Transportation Research Part B, 38(8), 733–749.Google Scholar
## Authors and Affiliations
• Chi Xie
• 1
• 2
• Xing Wu
• 3
• Stephen Boyles
• 4
1. 1.Key Laboratory of Road and Traffic Engineering of the Ministry of EducationTongji UniversityShanghaiChina
2. 2.School of Transportation EngineeringTongji UniversityShanghaiChina
3. 3.Department of Civil and Environmental EngineeringLamar UniversityBeaumontUSA
4. 4.Department of Civil, Architectural and Environmental EngineeringUniversity of Texas at AustinAustinUSA | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9366141557693481, "perplexity": 13180.913699366221}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-18/segments/1555578527720.37/warc/CC-MAIN-20190419121234-20190419143234-00557.warc.gz"} |
https://ftp.aimsciences.org/article/doi/10.3934/dcdsb.2021281 | # American Institute of Mathematical Sciences
doi: 10.3934/dcdsb.2021281
Online First
Online First articles are published articles within a journal that have not yet been assigned to a formal issue. This means they do not yet have a volume number, issue number, or page numbers assigned to them, however, they can still be found and cited using their DOI (Digital Object Identifier). Online First publication benefits the research community by making new scientific discoveries known as quickly as possible.
Readers can access Online First articles via the “Online First” tab for the selected journal.
## Stabilizing multiple equilibria and cycles with noisy prediction-based control
1 Dept. of Math. and Stats., University of Calgary, 2500 University Drive N.W. Calgary, AB, T2N 1N4, Canada 2 Department of Mathematics, the University of the West Indies, Mona Campus, Kingston, Jamaica
Received May 2020 Revised July 2021 Early access November 2021
Fund Project: E. Braverman is a corresponding author. The first author is supported by NSERC grant RGPIN-2020-03934
Pulse stabilization of cycles with Prediction-Based Control including noise and stochastic stabilization of maps with multiple equilibrium points is analyzed for continuous but, generally, non-smooth maps. Sufficient conditions of global stabilization are obtained. Introduction of noise can relax restrictions on the control intensity. We estimate how the control can be decreased with noise and verify it numerically.
Citation: Elena Braverman, Alexandra Rodkina. Stabilizing multiple equilibria and cycles with noisy prediction-based control. Discrete and Continuous Dynamical Systems - B, doi: 10.3934/dcdsb.2021281
##### References:
[1] M. Benaïm and S. J. Schreiber, Persistence and extinction for stochastic ecological models with internal and external variables, J. Math. Biol., 79 (2019), 393-431. doi: 10.1007/s00285-019-01361-4. [2] E. Braverman, C. Kelly and A. Rodkina, Stabilisation of difference equations with noisy prediction-based control, Physica D, 326 (2016), 21-31. doi: 10.1016/j.physd.2016.02.004. [3] E. Braverman, C. Kelly and A. Rodkina, Stabilization of cycles with stochastic prediction-based and target-oriented control, Chaos, 30 (2020), 093116, 15 pp. doi: 10.1063/1.5145304. [4] E. Braverman and E. Liz, On stabilization of equilibria using predictive control with and without pulses, Comput. Math. Appl., 64 (2012), 2192-2201. doi: 10.1016/j.camwa.2012.01.013. [5] E. Braverman and A. Rodkina, Stochastic control stabilizing unstable or chaotic maps, J. Difference Equ. Appl., 25 (2019), 151-178. doi: 10.1080/10236198.2018.1561882. [6] E. Braverman and A. Rodkina, Stochastic difference equations with the Allee effect, Discrete Contin. Dyn. Syst. Ser. A, 36 (2016), 5929-5949. doi: 10.3934/dcds.2016060. [7] P. Cull, Global stability of population models, Bull. Math. Biol., 43 (1981), 47-58. [8] E. Liz and D. Franco, Global stabilization of fixed points using predictive control, Chaos, 20 (2010), 023124, 9 pages. doi: 10.1063/1.3432558. [9] E. Liz and C. Pótzsche, PBC-based pulse stabilization of periodic orbits, Phys. D, 272 (2014), 26-38. doi: 10.1016/j.physd.2014.01.003. [10] P. Hitczenko and G. Medvedev, Stability of equilibria of randomly perturbed maps, Discrete Contin. Dyn. Syst. Ser. B, 22 (2017), 369-381. doi: 10.3934/dcdsb.2017017. [11] M. Nag and S. Poria, Synchronization in a network of delay coupled maps with stochastically switching topologies, Chaos Solitons Fractals, 91 (2016), 9-16. doi: 10.1016/j.chaos.2016.04.022. [12] M. Porfiri and I. Belykh, Memory matters in synchronization of stochastically coupled maps, SIAM J. Appl. Dyn. Syst., 16 (2017), 1372-1396. doi: 10.1137/17M111136X. [13] S. J. Schreiber, Coexistence in the face of uncertainty, Recent Progress and Modern Challenges in Applied Mathematics, Modeling and Computational Science, 349–384, Fields Inst. Commun., 79, Springer, New York, 2017. doi: 10.1007/978-1-4939-6969-2_12. [14] D. Singer, Stable orbits and bifurcation of maps of the interval, SIAM J. Appl. Math., 35 (1978), 260-267. doi: 10.1137/0135020. [15] A. N. Shiryaev, Probability, (2nd edition), Springer, Berlin, 1996. doi: 10.1007/978-1-4757-2539-1. [16] T. Ushio and S. Yamamoto, Prediction-based control of chaos, Phys. Lett. A, 264 (1999), 30-35. doi: 10.1016/S0375-9601(99)00782-3.
show all references
##### References:
[1] M. Benaïm and S. J. Schreiber, Persistence and extinction for stochastic ecological models with internal and external variables, J. Math. Biol., 79 (2019), 393-431. doi: 10.1007/s00285-019-01361-4. [2] E. Braverman, C. Kelly and A. Rodkina, Stabilisation of difference equations with noisy prediction-based control, Physica D, 326 (2016), 21-31. doi: 10.1016/j.physd.2016.02.004. [3] E. Braverman, C. Kelly and A. Rodkina, Stabilization of cycles with stochastic prediction-based and target-oriented control, Chaos, 30 (2020), 093116, 15 pp. doi: 10.1063/1.5145304. [4] E. Braverman and E. Liz, On stabilization of equilibria using predictive control with and without pulses, Comput. Math. Appl., 64 (2012), 2192-2201. doi: 10.1016/j.camwa.2012.01.013. [5] E. Braverman and A. Rodkina, Stochastic control stabilizing unstable or chaotic maps, J. Difference Equ. Appl., 25 (2019), 151-178. doi: 10.1080/10236198.2018.1561882. [6] E. Braverman and A. Rodkina, Stochastic difference equations with the Allee effect, Discrete Contin. Dyn. Syst. Ser. A, 36 (2016), 5929-5949. doi: 10.3934/dcds.2016060. [7] P. Cull, Global stability of population models, Bull. Math. Biol., 43 (1981), 47-58. [8] E. Liz and D. Franco, Global stabilization of fixed points using predictive control, Chaos, 20 (2010), 023124, 9 pages. doi: 10.1063/1.3432558. [9] E. Liz and C. Pótzsche, PBC-based pulse stabilization of periodic orbits, Phys. D, 272 (2014), 26-38. doi: 10.1016/j.physd.2014.01.003. [10] P. Hitczenko and G. Medvedev, Stability of equilibria of randomly perturbed maps, Discrete Contin. Dyn. Syst. Ser. B, 22 (2017), 369-381. doi: 10.3934/dcdsb.2017017. [11] M. Nag and S. Poria, Synchronization in a network of delay coupled maps with stochastically switching topologies, Chaos Solitons Fractals, 91 (2016), 9-16. doi: 10.1016/j.chaos.2016.04.022. [12] M. Porfiri and I. Belykh, Memory matters in synchronization of stochastically coupled maps, SIAM J. Appl. Dyn. Syst., 16 (2017), 1372-1396. doi: 10.1137/17M111136X. [13] S. J. Schreiber, Coexistence in the face of uncertainty, Recent Progress and Modern Challenges in Applied Mathematics, Modeling and Computational Science, 349–384, Fields Inst. Commun., 79, Springer, New York, 2017. doi: 10.1007/978-1-4939-6969-2_12. [14] D. Singer, Stable orbits and bifurcation of maps of the interval, SIAM J. Appl. Math., 35 (1978), 260-267. doi: 10.1137/0135020. [15] A. N. Shiryaev, Probability, (2nd edition), Springer, Berlin, 1996. doi: 10.1007/978-1-4757-2539-1. [16] T. Ushio and S. Yamamoto, Prediction-based control of chaos, Phys. Lett. A, 264 (1999), 30-35. doi: 10.1016/S0375-9601(99)00782-3.
The second iteration of the Ricker map for $r = 2.7$
The fourth iteration of the Ricker map for $r = 2.6$
A bifurcation diagram for the second iterate of the Ricker map with $r = 2.7$, $\alpha \in (0.1, 0.3)$ and (left) no noise, (right) $\ell = 0.15$
A bifurcation diagram for the third iterate of the Ricker map with $r = 3.5$ for $\alpha\in (0.75, 0.9)$ and (left) without noise, (right) $\ell = 0.06$. The last bifurcation leading to two stable equilibrium points occurs for $\alpha \approx 0.88$ in the deterministic case and $\alpha<0.86$ in the stochastic case
The graph of the map defined in (4.1), together with $y = x$
A bifurcation diagram for the map defined in \protect{(4.1)} with $\alpha \in (0.45, 0.65)$ and (left) no noise, we have two stable equilibrium points starting from $\alpha\approx 0.605$, (right) for Bernoulli noise with $\ell = 0.04$, the last bifurcation happens for smaller $\alpha\approx 0.535$. Here the two attractors correspond to two stable equilibrium points with separate basins of attraction, not to a cycle
[1] Elena Braverman, Alexandra Rodkina. Stabilization of difference equations with noisy proportional feedback control. Discrete and Continuous Dynamical Systems - B, 2017, 22 (6) : 2067-2088. doi: 10.3934/dcdsb.2017085 [2] Ionuţ Munteanu. Exponential stabilization of the stochastic Burgers equation by boundary proportional feedback. Discrete and Continuous Dynamical Systems, 2019, 39 (4) : 2173-2185. doi: 10.3934/dcds.2019091 [3] Martin Bohner, Sabrina Streipert. Optimal harvesting policy for the Beverton--Holt model. Mathematical Biosciences & Engineering, 2016, 13 (4) : 673-695. doi: 10.3934/mbe.2016014 [4] Hiroaki Morimoto. Optimal harvesting and planting control in stochastic logistic population models. Discrete and Continuous Dynamical Systems - B, 2012, 17 (7) : 2545-2559. doi: 10.3934/dcdsb.2012.17.2545 [5] Zhenyu Lu, Junhao Hu, Xuerong Mao. Stabilisation by delay feedback control for highly nonlinear hybrid stochastic differential equations. Discrete and Continuous Dynamical Systems - B, 2019, 24 (8) : 4099-4116. doi: 10.3934/dcdsb.2019052 [6] Fulvia Confortola, Elisa Mastrogiacomo. Feedback optimal control for stochastic Volterra equations with completely monotone kernels. Mathematical Control and Related Fields, 2015, 5 (2) : 191-235. doi: 10.3934/mcrf.2015.5.191 [7] John A. D. Appleby, Xuerong Mao, Alexandra Rodkina. On stochastic stabilization of difference equations. Discrete and Continuous Dynamical Systems, 2006, 15 (3) : 843-857. doi: 10.3934/dcds.2006.15.843 [8] Zhao-Han Sheng, Tingwen Huang, Jian-Guo Du, Qiang Mei, Hui Huang. Study on self-adaptive proportional control method for a class of output models. Discrete and Continuous Dynamical Systems - B, 2009, 11 (2) : 459-477. doi: 10.3934/dcdsb.2009.11.459 [9] Elena Braverman, Alexandra Rodkina. Stochastic difference equations with the Allee effect. Discrete and Continuous Dynamical Systems, 2016, 36 (11) : 5929-5949. doi: 10.3934/dcds.2016060 [10] Dianmo Li, Zengxiang Gao, Zufei Ma, Baoyu Xie, Zhengjun Wang. Two general models for the simulation of insect population dynamics. Discrete and Continuous Dynamical Systems - B, 2004, 4 (3) : 623-628. doi: 10.3934/dcdsb.2004.4.623 [11] B. E. Ainseba, W. E. Fitzgibbon, M. Langlais, J. J. Morgan. An application of homogenization techniques to population dynamics models. Communications on Pure and Applied Analysis, 2002, 1 (1) : 19-33. doi: 10.3934/cpaa.2002.1.19 [12] Robert Carlson. Myopic models of population dynamics on infinite networks. Networks and Heterogeneous Media, 2014, 9 (3) : 477-499. doi: 10.3934/nhm.2014.9.477 [13] Guangjun Shen, Xueying Wu, Xiuwei Yin. Stabilization of stochastic differential equations driven by G-Lévy process with discrete-time feedback control. Discrete and Continuous Dynamical Systems - B, 2021, 26 (2) : 755-774. doi: 10.3934/dcdsb.2020133 [14] Jacques Henry. For which objective is birth process an optimal feedback in age structured population dynamics?. Discrete and Continuous Dynamical Systems - B, 2007, 8 (1) : 107-114. doi: 10.3934/dcdsb.2007.8.107 [15] MirosŁaw Lachowicz, Tatiana Ryabukha. Equilibrium solutions for microscopic stochastic systems in population dynamics. Mathematical Biosciences & Engineering, 2013, 10 (3) : 777-786. doi: 10.3934/mbe.2013.10.777 [16] G. Buffoni, S. Pasquali, G. Gilioli. A stochastic model for the dynamics of a stage structured population. Discrete and Continuous Dynamical Systems - B, 2004, 4 (3) : 517-525. doi: 10.3934/dcdsb.2004.4.517 [17] Alexandra Rodkina, Henri Schurz. On positivity and boundedness of solutions of nonlinear stochastic difference equations. Conference Publications, 2009, 2009 (Special) : 640-649. doi: 10.3934/proc.2009.2009.640 [18] Yueh-Cheng Kuo, Huey-Er Lin, Shih-Feng Shieh. Asymptotic dynamics of hermitian Riccati difference equations. Discrete and Continuous Dynamical Systems - B, 2021, 26 (4) : 2037-2053. doi: 10.3934/dcdsb.2020365 [19] Xiujuan Wang, Mingshu Peng. Rich dynamics in some generalized difference equations. Discrete and Continuous Dynamical Systems - S, 2020, 13 (11) : 3205-3212. doi: 10.3934/dcdss.2020191 [20] Yuyun Zhao, Yi Zhang, Tao Xu, Ling Bai, Qian Zhang. pth moment exponential stability of hybrid stochastic functional differential equations by feedback control based on discrete-time state observations. Discrete and Continuous Dynamical Systems - B, 2017, 22 (1) : 209-226. doi: 10.3934/dcdsb.2017011
2020 Impact Factor: 1.327 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4528961777687073, "perplexity": 4101.719429149406}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662531779.10/warc/CC-MAIN-20220520093441-20220520123441-00592.warc.gz"} |
https://www.physicsforums.com/threads/concept-of-measurable-functions.110596/ | # Concept of measurable functions
1. Feb 14, 2006
### Castilla
First I had learned this definition of a "measurable function" (Apostol):
"Let I be an interval. A function f: I -> R is said to be measurable on I if there exists a sequence of step functions (s_n(x) ) such that s_n(x) -> f(x) as n -> infinity for almost all x in I."
But now in other sources (for example, the web notes of proffesor Dung Le) I have found this definition: "A function f: E -> R is measurable if E is a measurable set and for each real number r the set { x in E / f(x) > r } is measurable."
First I thought Apostol and Le were talking about different things, but afterwards I found that both use their definitions to prove similar theorems, as this one:
(In Apostol version):
"Suppose that I is an interval and that f, g are measurable functions on I. Then so are f + g, f - g, fg, |f|, max {f,g}, min {f,g}".
(In Dung Le version):
"Let f: E-> R and g: E -> R be measurable functions. Then the functions (k is a real) kf, f+ g, |f| and fg are measurable."
I was trying to learn the Fundamental Theorem of Calculus with Lebesgue integrals. Dung Le has it in his notes, but he uses the second definition of a measurable function and I have learned the basics of Lebesgue integration in Apostol, which only uses the first definition.
Furthermore, to proof the FTC I see that Dung Le use a lemma by which "the function equivalent to the infimun of a set of measurable functions is also measurable". But I dont know if this lemma has an equivalent in the Apostol approach and with Apostol's definition of a measurable function.
Is there is some way of reunite these two definitions in one?
2. Feb 14, 2006
### matt grime
I'm pretty sure that these are equivalent definitions. Measurable is such a universal term I do not believe there would be two inequivalent definitions for it.
Certainly Apostols' is equivalent to the second (step functions are measurable in the second sense, and hence since measurable functions are closed under limits, anything in Apostol's definition satisfies Le's), and the converse is to prove that step functions are dense in Le's definition which seems clear if messy: split the range up into intervals, inverse image of each is measurable, approximate with step functions which we can therefore do, yeah, ought to work.
Last edited: Feb 14, 2006
3. Feb 20, 2006
### Castilla
My "problem" is that I have learn some things about Lebesgue integration in Apostol's book but now it seems that to understand the Fundamental Theorem of Calculus for Lebesgue Integrals what I have learned helps little or nothing and I have to begin from zero with arid measure theory.
1. In the Apostol approach, the Lebesgue integral on an interval I is defined first for step functions (in that case is the same that the Riemann integral).
2. Then we define the "upper functions". f is an upper function iff:
- there exists a sequence of increasing step functions (s_n(x)) which converges to f(x) almost everwhere on I.
- there exists lim (n->oo) integral s_n(x)dx, and we define
integral f(x)dx = said limit.
3. Then we define Lebesgue functions this way: v is a Lebesgue function if there exists two upper functions f, g such that v = f - g.
We learn here the monotone convergente theorem, the beppo levi's theorem and the Lebesgue dominated theorem.
4. Then we define measurable functions (see Apostol's definition on my first post) and we learned, among others, the "diferentiation under the integral sign" theorem for lebesgue integrals.
All of this with little or nothing of Measure Theory.
But now I want to learn the FTC for Lebesgue integrals and in all sources I have found this theorem is embebbed on an approach completely based on dull, arid measure theory.
There must exist some book which shares Apostol approach and includes the FTC!! Or not?
Similar Discussions: Concept of measurable functions | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9868186712265015, "perplexity": 843.5255217139963}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886109670.98/warc/CC-MAIN-20170821211752-20170821231752-00511.warc.gz"} |
http://mathhelpforum.com/pre-calculus/126647-i-need-explanation.html | # Thread: I need an explanation
1. ## I need an explanation
Can anyone explain to me the Fibonacci rabbits problem in a simple way?
2. Just think of a line, and think of three points. You go down to the first point, then the second, and at the third the line diverges. Once the line has diverged the old line diverges at each point, but the new line must wait two points.
so we start with 1 line, it goes down to a point. Diverges and so on.
1.
1. (diverges)
2. (old diverges)
3. (old & 1new diverges)
5. (old and 1new diverges & 2new diverges)
8.
annnd there is gets too complex for me to think in my head... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8352718949317932, "perplexity": 1284.3870413278944}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-50/segments/1480698541066.79/warc/CC-MAIN-20161202170901-00080-ip-10-31-129-80.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/64407/is-the-extra-condition-in-this-definition-superfluous | # Is the extra condition in this definition superfluous?
I am learning Differential Geometry and someone told me that the second condition of a definition provided in books follows from the first and is hence superfluous. I cannot dispute it, so convince me if he is right.
Definition:
Suppose two curves $C_1$ and $C_2$ have a regular point P in common. Take a point A on $C_1$ near P and let $D_A$ be the point on $C_2$ closest to A (i.e orthogonal projection of A on $C_2$) then $C_2$ has contact of order $n$ with $C_1$ at P if
$$\lim_{A\to P} \dfrac{ \mbox{dist}(A,D_A)}{[\mbox{dist}(A,P)]^k}= \begin{cases} c\neq 0, & \text{if } \; k=n+1 \\ 0, & \text{if } \; k\leq n \end{cases}$$
Argument: $$\lim_{A\to P} \frac{AD_A}{(AP)^{n+1}} =c \neq 0$$ then $$\lim_{A\to P} \frac{AD_A}{(AP)^{n}} = \lim_{A\to P} AP \cdot \frac{AD_A}{(AP)^{n+1}}$$
$$= \lim_{A\to P} AP \cdot \lim_{A\to P} \frac{AD_A}{(AP)^{n+1}} = 0 \cdot c =0$$
The same process can be followed to show that the limit is zero for all $k\leq n$
Note: The above definition is claimed by the authors to be extracted from this original source
-
I am suspicious: the argument does not use the fact that $c \neq 0$. Instead you need that $|c| < \infty$. [Added: I think that the definition is an emphatic way of saying "the smallest $k$ such that $\lim_{A \to P} \frac{AD_A}{AP^{k+1}}$ is nonzero".] – Srivatsan Sep 15 '11 at 18:22
@Srivatsan why not? It uses the fact that the limit for $k=n+1$ is $c\neq 0$ to show that the limit would be zero for every $k\leq n$. Re: additional comment, I agree, specially after seeing this argument. I need a confirmation that nothing fishy is going on as this refutes an argument presented in two books. – kuch nahi Sep 16 '11 at 6:38
@Srivatsan Yes. So I guess this person's argument is right. The statement should be that order is the minimum $n$ for which the stated limit is non zero and finite. – kuch nahi Sep 16 '11 at 6:43
Nonzero, yes. But I am not sure about finite. (Also note that the limit is nonzero for $k=n+1$, not $k=n$. So it's more like the the maximum $n$ for which the limit is zero.) – Srivatsan Sep 16 '11 at 6:46
@Srivatsan if it is not finite then we cannot conclude that $0\cdot c =0$ and the argument won't stand. – kuch nahi Sep 16 '11 at 6:48 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9663727283477783, "perplexity": 234.39982872546622}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398445208.17/warc/CC-MAIN-20151124205405-00131-ip-10-71-132-137.ec2.internal.warc.gz"} |
http://www.planetmath.org/integrationunderintegralsign | # integration under integral sign
Let
$I(\alpha)\;=\;\int_{a}^{b}\!f(x,\,\alpha)\,dx.$
where $f(x,\,\alpha)$ is continuous in the rectangle
$a\leqq x\leqq b,\,\quad\alpha_{1}\leqq\alpha\leqq\alpha_{2}.$
Then $\alpha\mapsto I(\alpha)$ is continuous and hence integrable (http://planetmath.org/RiemannIntegrable) on the interval$\alpha_{1}\leqq\alpha\leqq\alpha_{2}$; we have
$\int_{\alpha_{1}}^{\alpha_{2}}I(\alpha)\,d\alpha\;=\;\int_{\alpha_{1}}^{\alpha% _{2}}\left(\int_{a}^{b}\!f(x,\,\alpha)\,dx\right)d\alpha.$
This is a double integral over a in the $x\alpha$-plane, whence one can change the order of integration (http://planetmath.org/FubinisTheorem) and accordingly write
$\int_{\alpha_{1}}^{\alpha_{2}}\left(\int_{a}^{b}\!f(x,\,\alpha)\,dx\right)d% \alpha\;=\;\int_{a}^{b}\left(\int_{\alpha_{1}}^{\alpha_{2}}\!f(x,\,\alpha)\,d% \alpha\right)dx.$
Thus, a definite integral depending on a parametre may be integrated with respect to this parametre by performing the integration under the integral sign.
Example. For being able to evaluate the improper integral
$I\;=\;\int_{0}^{\infty}\frac{e^{-ax}-e^{-bx}}{x}\,dx\qquad(a>0,\;b>0),$
we may interprete the integrand as a definite integral:
$\frac{e^{-ax}-e^{-bx}}{x}\;=\;\operatornamewithlimits{\Big{/}}_{\!\!\!\alpha=b% }^{\,\quad a}\!\frac{e^{-\alpha x}}{x}\;=\;\int_{a}^{b}\!e^{-\alpha x}\,d\alpha.$
Accordingly, we can calculate as follows:
$\displaystyle I$ $\displaystyle\;=\;\int_{0}^{\infty}\left(\int_{a}^{b}\!e^{-\alpha x}\,d\alpha% \right)dx$ $\displaystyle\;=\;\int_{a}^{b}\left(\int_{0}^{\infty}\!e^{-\alpha x}\,dx\right% )d\alpha$ $\displaystyle\;=\;\int_{a}^{b}\left(\operatornamewithlimits{\Big{/}}_{\!\!\!x=% 0}^{\,\quad\infty}\!-\frac{e^{-\alpha x}}{\alpha}\right)d\alpha$ $\displaystyle\;=\;\int_{a}^{b}\!\frac{1}{\alpha}\,d\alpha\;=\;% \operatornamewithlimits{\Big{/}}_{\!\!\!a}^{\,\quad b}\!\ln{\alpha}$ $\displaystyle\;=\;\ln\frac{b}{a}$
Title integration under integral sign IntegrationUnderIntegralSign 2013-03-22 18:46:27 2013-03-22 18:46:27 pahio (2872) pahio (2872) 5 pahio (2872) Theorem msc 26A42 FubinisTheorem DifferentiationUnderIntegralSign RelativeOfExponentialIntegral | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 16, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9994356632232666, "perplexity": 1665.6927239080617}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794867977.85/warc/CC-MAIN-20180527004958-20180527024958-00094.warc.gz"} |
http://www.zazzle.co.uk/sea+lion+cards | Showing All Results
1,160 results
Page 1 of 20
Related Searches: seal lover, seal design, seal photo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
£2.50
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
£2.50
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
Got it! We won't show you this product again!
Undo
No matches for
Showing All Results
1,160 results
Page 1 of 20 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.812705934047699, "perplexity": 4552.2053927430925}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-15/segments/1398223206118.10/warc/CC-MAIN-20140423032006-00053-ip-10-147-4-33.ec2.internal.warc.gz"} |
https://chemistry.stackexchange.com/questions/22100/is-the-aromaticity-broken-in-some-resonance-structures-of-para-nitro-aminobenzen | # Is the aromaticity broken in some resonance structures of para-nitro-aminobenzene?
According to my course of organic chemistry, para-nitro-aminobenzene has to break his aromaticity to delocalize the electrons of the amino-group in the nitro-group. I don't really see this, when I draw the resonance structures.
• @Simon Ravelingien - why does your diagram use equilibrium arrows to show resonance contributors? – Dissenter Dec 26 '14 at 17:34
• As far as I am aware the aromaticity is not broken – bon Dec 26 '14 at 17:46
• You need three conjugated pi bonds in the ring to conserve aromaticity in this system. The molecule's "true" structure is a weighted sum of the resonance structures; you therefore would expect a partial loss of aromaticity compared to benzene. – J. LS Dec 26 '14 at 18:15
• What do you mean by loss of aromaticity? – Dissenter Dec 27 '14 at 12:00
• I agree with Dissenter, the convention is to use a double headed arrow for resonance structures. It helps people be aware of the difference between resonance structures and different species in equilibrium. – iad22agp Dec 27 '14 at 23:23
Your teacher is correct, some of the resonance structures in your figure are not aromatic. Still though, as resonance structures they contribute to the overall description of the molecule, just less than the structures that are aromatic. The resonance structures at the right and left end of your figure are aromatic. The fourth resonance structure (the one in the middle) is referred to as being a "quinone" rather than an aromatic.
o- and p-benzoquinone are examples of quinones; they are not aromatic compounds (ref, note the sentence "Quinones are conjugated but not aromatic").
Likewise, their carbon analogues, o- and p-xylylene are also non-aromatic quinoid-like compounds.
For a compound to be aromatic it must be
• cyclic
• contain 4n+2 pi electrons
• have a continuous loop of p-orbitals
• and you must be able to draw double bonds - internal to the ring - from each ring carbon atom.
It is this last point that serves to differentiate quinones and quinone-like molecules from aromatic compounds.
Finally, aromatic compounds need not be planar, deviations in excess of 15° from planarity can be tolerated and the molecule can remain aromatic (see, for example, [6]-paracyclophane)
• Can benzoquinone be called anti-aromatic since it has 4n pi electrons? – ChemExchange Mar 28 '15 at 4:34
• @ChemExchange No, benzoquinone is not anti-aromatic, it is not a simple cyclic array of 4 pi electrons. In fact, anti-aromatic compounds distort to some other geometry so they are no longer anti-aromatic and hence, more stable. – ron Mar 28 '15 at 13:46
• @ChemExchange ron is right, but your point is valid - you can indeed write some anti-aromatic mesomeric structures for quinones, but as their are destabilizing, they aren't major contributors - in tropone it's the other way round. – Mithoron Mar 28 '15 at 16:00
• – Mithoron Apr 8 '15 at 22:34
• @ChemExchange I might post an answer in a while, but I am not going to participate in an extensive chat about it. Sorry I am too busy for that. In the meantime you can have a look at this answer of mine. Aromaticity is not a very well defined concept and I also believe that it is hard to tell apart from overall resonance stabilisation. Hückel's rules are nice guidelines, but they are not the definition of aromaticity. This is always taught wrong. They also do not explain Y-aromaticity and sigma aromaticity... – Martin - マーチン Apr 14 '15 at 11:47
Aromaticity is not a very well defined concept (there are no strict rules) and I also believe that it is hard to tell apart from overall resonance stabilisation. The IUPAC goldbook states for aromatic:
aromatic
1. In the traditional sense, 'having a chemistry typified by benzene'.
2. A cyclically conjugated molecular entity with a stability (due to delocalization ) significantly greater than that of a hypothetical localized structure (e.g. Kekulé structure ) is said to possess aromatic character. If the structure is of higher energy (less stable) than such a hypothetical classical structure, the molecular entity is 'antiaromatic'. The most widely used method for determining aromaticity is the observation of diatropicity in the 1H NMR spectrum.
3. The terms aromatic and antiaromatic have been extended to describe the stabilization or destabilization of transition states of pericyclic reactions The hypothetical reference structure is here less clearly defined, and use of the term is based on application of the Hückel (4n + 2) rule and on consideration of the topology of orbital overlap in the transition state. Reactions of molecules in the ground state involving antiaromatic transition states proceed, if at all, much less easily than those involving aromatic transition states.
Hückel's set of rules are often used as nice guidelines, but they are not the definition of aromaticity. In fact they are very, very rigid and strict and most of the compounds you'd usually consider being aromatic in this context, do not comply with these rules. The IUPAC goldbook defines:
Hückel (4n + 2) rule
Monocyclic planar (or almost planar) systems of trigonally (or sometimes digonally) hybridized atoms that contain (4n + 2) π-electrons (where n is a non-negative integer) will exhibit aromatic character. The rule is generally limited to n = 0–5. This rule is derived from the Hückel MO calculation on planar monocyclic conjugated hydrocarbons (CH)m where m is an integer equal to or greater than 3 according to which (4n + 2) π-electrons are contained in a closed-shell system.
In this framework only the first and the last structure obey Hückel's rule. The proton and carbon NMR clearly proof that p-nitroanniline is an aromatic compound, the spectrum is very close to the data of benzene.
Resonance structures are just a crutch to explain a very complicated and complex electronic structure in simple and understandable terms, i.e. Lewis structures. In highly delocalised systems a superposition of all resonance structures has to be considered to paint a somewhat conclusive picture of the bonding situation. There are contributions of different structures and not all of them may be equal in the overall description, however, they do not change the fact, that the experimental property is observed. This is again a case, where you can see the limitations of the resonance concept.
All the resonating structures follow Huckel's Rule and so they are not losing their aromaticity.
• Planar Cyclic Ring
• 4n+2 pi-electrons (the exocyclic pi electrons are not considered)1,2.
• All atoms of the ring in conjugation
A classic example of an aromatic cabanion is cyclopentadiene ion.
The negative charge or the lone pair is in resonance and is in an unhybridised orbital. Hence it gives $sp^2$ and not $sp^3$. So its planar.
• Are the structures with a negative charge at a carbon atom really planar? I would expect tetrahedral bonding angles for those. – Curt F. Mar 27 '15 at 18:12
• @CurtF. the phenyl ring is a hexagon (or near enough) so it cant have tetrahedral angles – bon Mar 27 '15 at 19:17
• Can you really say that any of the resonance structures in the middle have 6 pi electrons in the ring? Each (ring) double bond counts for two electrons, the lone pair counts for two electrons so we're up to 6 electrons right there. The exocyclic pi bond counts for zero? One? Two? – jerepierre Mar 27 '15 at 19:52
• @CurtF. asked, "Are the structures with a negative charge at a carbon atom really planar?" Yes. The cardinal rule for resonance structures is that nuclear positions cannot change. So since the aromatic ring is planar, so must it be in the resonance structures. You're right that carbon with a negative charge would prefer to be non-planar. Since it can't deform in the resonance structures, that tells us that those resonance structures contribute less to the "real" structure. – ron Mar 27 '15 at 19:52
• @CurtF. A classic example of an aromatic cabanion is cyclopentadiene – ChemExchange Mar 28 '15 at 4:28 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7305170297622681, "perplexity": 1538.4222544770491}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540565544.86/warc/CC-MAIN-20191216121204-20191216145204-00180.warc.gz"} |
https://cosmocoffee.info/viewtopic.php?f=11&t=3665&p=10034&sid=69c11910bf9cc2c9d10997963f51c889 | CAMB: output power spectrum
Use of Cobaya. camb, CLASS, cosmomc, compilers, etc.
Zhuangfei Wang
Posts: 27
Joined: October 09 2021
Affiliation: Simon Fraser University
CAMB: output power spectrum
Hello:
I have two simple questions on outputting the power spectrum from CAMB.
1. How to output 2D spectrum galaxy number count from CAMB? I checked all the outputted files, but only found 2D specturm for T, E, B, Phi, both auto and cross-correlations, instead of galaxy count.
2. I tried to output 3D spectrum for P_{d,Weyl} but didn't get the results(basically NAN as output). And is the same when I added a new variable for cross-correlation, say, P_{d,Psi}, with Psi one of the gravitational potentials. However, it works when I outputted P_{Weyl,Weyl} or P_{Psi,Psi}, which is confusing to me. So could you tell me how to do this properly or if I have made any mistakes? As for the outputting script, I simply used the example from: https://camb.readthedocs.io/en/latest/CAMBdemo.html, thus should be fine and it works for all the other variable pairs.
Many thanks!
Antony Lewis
Posts: 1852
Joined: September 23 2004
Affiliation: University of Sussex
Contact:
Re: CAMB: output power spectrum
By "d" you mean delta_tot?
Box 36 in the example notebook shows how to get C_L cross-spectra from counts.
Zhuangfei Wang
Posts: 27
Joined: October 09 2021
Affiliation: Simon Fraser University
Re: CAMB: output power spectrum
Thanks a lot.
Yes, d means delta_tot.
Zhuangfei Wang
Posts: 27
Joined: October 09 2021
Affiliation: Simon Fraser University
Re: CAMB: output power spectrum
Hello, I am still having trouble with question 2 above. It would be nice if you could give some directions. Thanks.
Antony Lewis
Posts: 1852
Joined: September 23 2004
Affiliation: University of Sussex
Contact:
Re: CAMB: output power spectrum
It's not very clear what you are doing, "added new variable"? Please give complete code that reproduces any issue.
Zhuangfei Wang
Posts: 27
Joined: October 09 2021
Affiliation: Simon Fraser University
Re: CAMB: output power spectrum
Hi Antony. Sorry for not making clear the question here. Basically, I was trying to output the cross-power spectrum P_{delta_tot, Weyl}. I made a simple script as below to run it, but I only got NAN outputted. The same script outputs normally for other pairs like P_{delta_tot, delta_tot} or P_{Weyl, Weyl}, so I am confused about it. Thanks.
===
from camb import model
from camb.camb import get_matter_power_interpolator
from camb import camb
import numpy as np
#parameter settings
pars =model.CAMBparams()
pars.set_cosmology(H0=70, ombh2=0.0226, omch2=0.112, mnu=0.06, omk=0)
pars.set_dark_energy()
pars.InitPower.set_params(ns=0.96)
pars.WantTransfer = True
zbins = 15
kpoints = 200
zrange=np.linspace(0,1,zbins, endpoint=False)
pars.set_matter_power(redshifts=zrange,kmax=2.0)
pars.NonLinear = model.NonLinear_none
results = camb.get_results(pars)
kh, z, pk_dd = results.get_matter_power_spectrum(minkh=1e-4, maxkh=1, npoints = 200,
var1 = model.Transfer_tot, var2 = model.Transfer_Weyl)
print(pk_dd)
===
Antony Lewis
Posts: 1852
Joined: September 23 2004
Affiliation: University of Sussex
Contact:
Re: CAMB: output power spectrum
That code runs fine for me, outputting
Code: Select all
Note: redshifts have been re-sorted (earliest first)
[[2.43416726e-22 2.42966500e-22 2.42517106e-22 ... 1.69027924e-22
1.68715288e-22 1.68403230e-22]
[2.43416726e-22 2.42966500e-22 2.42517106e-22 ... 1.69027924e-22
1.68715288e-22 1.68403230e-22]
[2.43416726e-22 2.42966500e-22 2.42517106e-22 ... 1.69027924e-22
1.68715288e-22 1.68403230e-22]
...
[2.43416726e-22 2.42966500e-22 2.42517106e-22 ... 1.69027924e-22
1.68715288e-22 1.68403230e-22]
[2.43416726e-22 2.42966500e-22 2.42517106e-22 ... 1.69027924e-22
1.68715288e-22 1.68403230e-22]
[2.43416726e-22 2.42966500e-22 2.42517106e-22 ... 1.69027924e-22
1.68715288e-22 1.68403230e-22]]
Zhuangfei Wang
Posts: 27
Joined: October 09 2021
Affiliation: Simon Fraser University
Re: CAMB: output power spectrum
Thanks, Antony. Although the code using "get_matter_power_spectrum" could output values for {matter, Weyl}, the order e-22 is too low and doesn't make sense to me. For example, if using the code of box 32 at: https://camb.readthedocs.io/en/latest/CAMBdemo.html, with "get_matter_power_interpolator", but changing the var pairs into {matter, Weyl}, I can get the output of PK as:
Code: Select all
[-4.55433315e-05 -4.86949737e-05 -5.20640957e-05 -5.56655683e-05
-5.95152092e-05 -6.36299160e-05 -6.80277085e-05 -7.27277540e-05
-7.77505092e-05 -8.31176830e-05 -8.88522737e-05 -9.49788558e-05
-1.01523506e-04 -1.08513838e-04 -1.15979127e-04 -1.23950442e-04
-1.32460637e-04 -1.41544315e-04 -1.51238090e-04 -1.61580627e-04
-1.72612632e-04 -1.84376759e-04 -1.96917827e-04 -2.10282790e-04
-2.24520461e-04 -2.39681642e-04 -2.55818990e-04 -2.72986735e-04
-2.91240300e-04 -3.10636319e-04 -3.31232395e-04 -3.53086318e-04
-3.76256433e-04 -4.00800800e-04 -4.26775398e-04 -4.54235582e-04
-4.83234070e-04 -5.13818232e-04 -5.46031128e-04 -5.79910412e-04
-6.15486699e-04 -6.52781451e-04 -6.91806431e-04 -7.32562063e-04
-7.75034878e-04 -8.19196689e-04 -8.65001993e-04 -9.12384825e-04
-9.61256928e-04 -1.01150533e-03 -1.06298990e-03 -1.11554087e-03
-1.16895067e-03 -1.22298193e-03 -1.27737961e-03 -1.33179034e-03
-1.38580438e-03 -1.43901208e-03 -1.49097862e-03 -1.54120437e-03
-1.58911050e-03 -1.63406245e-03 -1.67537843e-03 -1.71233747e-03
-1.74418495e-03 -1.77012320e-03 -1.78933743e-03 -1.80102449e-03
-1.80441160e-03 -1.79879660e-03 -1.78359176e-03 -1.75837734e-03
-1.72296437e-03 -1.67745421e-03 -1.62230518e-03 -1.55839759e-03
-1.48704961e-03 -1.41001782e-03 -1.32950038e-03 -1.24794890e-03
-1.16796556e-03 -1.09226368e-03 -1.02263443e-03 -9.60643929e-04
-9.08129034e-04 -8.63538713e-04 -8.24311579e-04 -7.87753863e-04
-7.50391131e-04 -7.07732636e-04 -6.56141574e-04 -5.96192231e-04
-5.32863453e-04 -4.72921312e-04 -4.22749357e-04 -3.86606649e-04
-3.63194648e-04 -3.44775638e-04 -3.22031132e-04 -2.90895149e-04
-2.55801955e-04 -2.26274557e-04 -2.07913655e-04 -1.95303074e-04
-1.79429445e-04 -1.59177825e-04 -1.42310287e-04 -1.31632804e-04
-1.21137993e-04 -1.08810557e-04 -9.92737473e-05 -9.17077245e-05
-8.35773739e-05 -7.69351913e-05 -7.10834663e-05 -6.55730039e-05
-6.09026271e-05 -5.65506655e-05 -5.27287025e-05 -4.92297166e-05
-4.60692272e-05 -4.31768722e-05 -4.05162243e-05 -3.80438890e-05
-3.57313092e-05 -3.35536588e-05 -3.14880174e-05 -2.95153065e-05
-2.76210029e-05 -2.57960239e-05 -2.40339889e-05 -2.23311224e-05
-2.06875058e-05 -1.91043104e-05 -1.75835282e-05 -1.61292268e-05
-1.47451869e-05 -1.34344542e-05 -1.22000997e-05 -1.10441486e-05
-9.96734615e-06 -8.96941380e-06 -8.04908728e-06 -7.20423146e-06
-6.43197804e-06 -5.72893058e-06 -5.09132326e-06 -4.51512811e-06
-3.99618080e-06 -3.53026874e-06 -3.11313115e-06 -2.74060820e-06
-2.40873184e-06 -2.11371434e-06 -1.85199699e-06 -1.62028057e-06
-1.41552306e-06 -1.23492886e-06 -1.07593580e-06 -9.36195024e-07
-8.13568536e-07 -7.06125689e-07 -6.12128095e-07 -5.30014293e-07
-4.58384955e-07 -3.95989045e-07 -3.41710693e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07
-3.15603748e-07 -3.15603748e-07 -3.15603748e-07 -3.15603748e-07]
where the order of magnitude makes more sense. So I was wondering whether we could only use "get_matter_power_interpolator" to calculate PK regarding Weyl potentials, but not "get_matter_power_spectrum"? If so, what makes that difference?
Besides, I also tried outputting the matter power spectrum(delta_tot, delta_tot) with both methods of "get_matter_power_interpolator" and "get_matter_power_spectrum" using the code below, and found that there is a big difference on the outputted PK(pk1 vs pk2) at redshift z =0. So which one should be standard result?
Code: Select all
from camb import model
from camb.camb import get_matter_power_interpolator
from camb import camb
import numpy as np
import matplotlib.pyplot as plt
nz = 100 #number of steps to use for the radial/redshift integration
kmax=2 #kmax to use
h=0.7
pars = camb.CAMBparams()
pars.set_cosmology(H0=70, ombh2=0.0226, omch2=0.112, mnu=0.06, omk=0)
pars.set_dark_energy()
pars.InitPower.set_params(ns=0.96)
pars.WantTransfer = True
#get_matter_power_interpolator
results= camb.get_background(pars)
chistar = results.conformal_time(0)- results.tau_maxvis
chis = np.linspace(0,chistar,nz)
chis = chis[1:-1]
zs = zs[1:-1]
PK = camb.get_matter_power_interpolator(pars, nonlinear=False,
hubble_units=False, k_hunit=False, kmax=kmax,
var1=model.Transfer_tot,var2=model.Transfer_tot, zmin=0.,zmax=zs[-1])
k=np.exp(np.log(10)*np.linspace(-4,0,200))*h
pk1 = PK.P(0,k)
#get_matter_power_spectrum
pars.set_matter_power(redshifts=[0.],kmax=2.0)
pars.NonLinear = model.NonLinear_none
results = camb.get_results(pars)
kh, z, pk2 = results.get_matter_power_spectrum(minkh=1e-4, maxkh=1, npoints = 200,
var1 = model.Transfer_tot, var2 = model.Transfer_tot)
Thanks a lot!
Antony Lewis
Posts: 1852
Joined: September 23 2004
Affiliation: University of Sussex
Contact:
Re: CAMB: output power spectrum
If you set hubble_units=True, k_hunit=True, and remove the *h, then the results agree.
For the Weyl-cross, I think there is a bug in get_matter_power_spectrum for spectra that are negative.
To get a grid you can use results.get_[non]linear_matter_power_spectrum.
Antony Lewis
Posts: 1852
Joined: September 23 2004
Affiliation: University of Sussex
Contact:
Re: CAMB: output power spectrum
Zhuangfei Wang
Posts: 27
Joined: October 09 2021
Affiliation: Simon Fraser University
Re: CAMB: output power spectrum
OK that makes sense now. Thanks a lot. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2614508271217346, "perplexity": 20786.61263550476}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500028.12/warc/CC-MAIN-20230202133541-20230202163541-00048.warc.gz"} |
http://rosa.unipr.it/FSDA/dempk.html | # dempk
dempk performs a merging of components found by tkmeans
## Syntax
• out=dempk(Y, k, g)example
• out=dempk(Y, k, g,Name,Value)example
## Description
The function dempk performs either a hierarchical merging of the k components found by tkmeans (using the pairwise overlap values between them and giving g clusters), or if g is a decimal number between 0 and 1 it performs the merging phase according to the threshold g (the same algorithm as overlapmap).
out =dempk(Y, k, g) Example using dempk on data obtained by simdataset, specifying both hierarchical clustering and a threshold value, in order to obtain additional plots.
out =dempk(Y, k, g, Name, Value) Example using dempk with hierarchical merging on data obtained by simdataset, specifying additional arguments in the call to tkmeans.
## Examples
expand all
### Example using dempk on data obtained by simdataset, specifying both hierarchical clustering and a threshold value, in order to obtain additional plots.
close all
% Specify k cluster in v dimensions with n obs
k = 10;
v = 2;
n = 5000;
% Generate homogeneous and spherical clusters
rng(100, 'twister');
out = MixSim(k, v, 'sph', true, 'hom', true, 'int', [0 10], 'Display', 'off', 'BarOmega', 0.05, 'Display','off');
% Simulating data
[X, id] = simdataset(n, out.Pi, out.Mu, out.S);
% Plotting data
gscatter(X(:,1), X(:,2), id);
str = sprintf('Simulated data with %d groups in %d dimensions and %d units', k, v, n);
title(str,'Interpreter','Latex');
% merging algorithm based on hierarchical clustering
g = 3;
DEMP = dempk(X, k*5, g, 'plots', 'contourf');
% merging algorithm based on the threshold value omega star
g = 0.01;
DEMP2 = dempk(X, k*5, g, 'plots', 'contour');
cascade;
Total estimated time to complete trimmed k means: 23.65 seconds
------------------------------
Warning: Number of subsets without convergence equal to 36.6667%
Total estimated time to complete trimmed k means: 1.56 seconds
------------------------------
Warning: Number of subsets without convergence equal to 38.6667%
### Example using dempk with hierarchical merging on data obtained by simdataset, specifying additional arguments in the call to tkmeans.
close all
% Specify k cluster in v dimensions with n obs
g = 3;
v = 2;
n = 5000;
% null trimming and noise level
alpha0 = 0;
% restriction factor
restr = 30;
% Maximum overlap
maxOm = 0.005;
% Generate heterogeneous and elliptical clusters
rng(500, 'twister');
out = MixSim(g, v, 'sph', false, 'restrfactor', restr, 'int', [0 10], ...
'Display', 'off', 'MaxOmega', maxOm, 'Display','off');
% Simulating data
[X, id] = simdataset(n, out.Pi, out.Mu, out.S);
% Plotting data
gg = gscatter(X(:,1), X(:,2), id);
str = sprintf('Simulated data with %d groups in %d dimensions and %d \nunits, with restriction factor %d and maximum overlap %.2f', ...
g, v, n, restr, maxOm);
title(str,'Interpreter','Latex', 'fontsize', 12);
set(findobj(gg), 'MarkerSize',10);
legend1 = legend(gca,'show');
set(legend1,'LineWidth',1,'Interpreter','latex','FontSize',14, 'Location', 'northwest')
% number of components searched by tkmeans
k = g * 6;
tkmeansOpt = struct;
tkmeansOpt.reftol = 0.0001;
tkmeansOpt.msg = 1;
tkmplots = struct;
tkmplots.type = 'contourf';
tkmplots.cmap = [0.3 0.2 0.4; 0.4 0.5 0.5; 0.1 0.7 0.9; 0.5 0.3 0.8; 1 1 1];
tkmeansOpt.plots = tkmplots;
tkmeansOpt.nomes = 0;
% saving tkmeans output
tkmeansOut = 1;
DEMP = dempk(X, k, g, 'tkmeansOpt', tkmeansOpt, 'plots', 'ellipse');
cascade;
Total estimated time to complete trimmed k means: 0.59 seconds
------------------------------
Warning: Number of subsets without convergence equal to 21.6667%
## Related Examples
expand all
### Example using dempk with hierarchical merging on data obtained by simdataset, specifying additional arguments in the call to clusterdata.
close all
% Specify k cluster in v dimensions with n obs
g = 3;
v = 2;
n = 5000;
% null trimming and noise level
alpha0 = 0;
% restriction factor
restr = 30;
% Maximum overlap
maxOm = 0.005;
% Generate heterogeneous and elliptical clusters
rng(500, 'twister');
out = MixSim(g, v, 'sph', false, 'restrfactor', restr, 'int', [0 10], ...
'Display', 'off', 'MaxOmega', maxOm, 'Display','off');
% Simulating data
[X, id] = simdataset(n, out.Pi, out.Mu, out.S);
% Plotting data
gg = gscatter(X(:,1), X(:,2), id);
str = sprintf('Simulated data with %d groups in %d dimensions and %d \nunits, with restriction factor %d and maximum overlap %.2f', ...
g, v, n, restr, maxOm);
title(str,'Interpreter','Latex', 'fontsize', 12);
set(findobj(gg), 'MarkerSize',10);
legend1 = legend(gca,'Group 1','Group 2','Group 3');
set(legend1,'LineWidth',1,'Interpreter','latex','FontSize',12, 'Location', 'northwest')
% number of components searched by tkmeans
disp('RUNNING TKMEANS WITH 18 COMPONENTS; THEN MERGING WITH dempk');
k = g * 6;
% additional input for clusterdata (i.e. hierOpt)
cascade;
RUNNING TKMEANS WITH 18 COMPONENTS; THEN MERGING WITH dempk
Total estimated time to complete trimmed k means: 0.66 seconds
------------------------------
Warning: Number of subsets without convergence equal to 37.3333%
### Example using dempk, both setting a threshold and performing a hierarchical merging, for data obtained by simdataset with 10 percent uniform noise.
close all
% Specify k cluster in v dimensions with n obs
g = 3;
v = 2;
n = 5000;
% 10 percent trimming and uniform noise
alpha = 0.1;
noise = alpha*n;
% restriction factor
restr = 30;
% Maximum overlap
maxOm = 0.005;
% Generate heterogeneous and elliptical clusters
rng(500, 'twister');
out = MixSim(g, v, 'sph', false, 'restrfactor', restr, 'int', [0 10], ...
'Display', 'off', 'MaxOmega', maxOm, 'Display','off');
% Simulating data
[X,id] = simdataset(n, out.Pi, out.Mu, out.S, 'noiseunits', noise);
% Plotting data
gg = gscatter(X(:,1), X(:,2), id);
str = sprintf('Simulating %d groups in %d dimensions and %d units with %d%s \nuniform noise, setting a restriction factor %d and maximum overlap %.2f', ...
g, v, n, alpha*100, '\%', restr, maxOm);
title(str,'Interpreter','Latex', 'fontsize', 10);
set(findobj(gg), 'MarkerSize',10);
legend1 = legend(gca,'Outliers','Group 1','Group 2','Group 3');
set(legend1,'LineWidth',1,'Interpreter','latex','FontSize',12, 'Location', 'northwest')
% fixing the number of components searched by tkmeans
k = g * 6;
% dempk with hierarchical merging and trimming equal to the level of noise
DEMP = dempk(X, k, g, 'alpha', alpha, 'plots', 'contourf');
% dempk with a threshold value and trimming equal to the level of noise
g = 0.025;
DEMP = dempk(X, k, g, 'alpha', alpha, 'plots', 'contourf');
cascade;
Total estimated time to complete trimmed k means: 8.45 seconds
------------------------------
Warning: Number of subsets without convergence equal to 38%
Total estimated time to complete trimmed k means: 11.87 seconds
------------------------------
Warning: Number of subsets without convergence equal to 36%
### Example using the M5 dataset and various setting for dempk, using hierarchical clustering, in order to identify the real clusters using different strategies.
close all
id = Y(:,3);
Y = Y(:, 1:2);
G = max(id);
n = length(Y);
noise = length(Y(id==0, 1));
v = 2; % dimensions
id(id==0) = -1; % changing noise label
gg = gscatter(Y(:,1), Y(:,2), id);
str = sprintf('M5 data set with %d groups in %d dimensions and \n%d units where %d%s of them are noise', G, v, n, noise/n*100, '\%');
title(str,'Interpreter','Latex', 'fontsize', 12);
set(findobj(gg), 'MarkerSize',12);
legend1 = legend(gca,'Outliers','Group 1','Group 2','Group 3');
set(legend1,'LineWidth',1,'Interpreter','latex','FontSize',12, 'Location', 'northwest')
% number of components to search
k = G*5;
% null trimming and noise level
alpha0 = 0;
% mimimum overlap cut-off value between pair of merged components
omegaStar = 0.045;
DEMP = dempk(Y, k, G, 'alpha', alpha0, 'tkmeansOut', 1, 'plots', 1);
% setting alpha equal to noise level (usually not appropriate)
alpha = noise/n;
DEMP2 = dempk(Y, k, G, 'alpha', alpha, 'tkmeansOut', 1, 'plots', 1);
% setting alpha greater than the noise level (almost always appropriate)
DEMP3 = dempk(Y, k, G, 'alpha', alpha+0.04, 'tkmeansOut', 1, 'plots', 1);
cascade;
Total estimated time to complete trimmed k means: 0.28 seconds
------------------------------
Warning: Number of subsets without convergence equal to 36%
Total estimated time to complete trimmed k means: 3.02 seconds
------------------------------
Warning: Number of subsets without convergence equal to 39%
Total estimated time to complete trimmed k means: 3.20 seconds
------------------------------
Warning: Number of subsets without convergence equal to 38.6667%
## Input Arguments
### Y — Input data. Matrix.
n x v data matrix. n observations and v variables. Rows of Y represent observations, and columns represent variables. Missing values (NaN's) and infinite values (Inf's) are allowed, since observations (rows) with missing or infinite values will automatically be excluded from the computations.
Data Types: single | double
### k — Number of components searched by tkmeans algorithm. Integer scalar.
Data Types: single | double
### g — Merging rule. Scalar.
Number of groups obtained by hierarchical merging, or threshold of the pairwise overlap values (i.e. omegaStar) if 0<g<1.
Data Types: single | double
### Name-Value Pair Arguments
Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.
Example: 'alpha', 0.05 , 'plots', 1 , 'tkmeansOpt.reftol', 0.0001 , 'tkmeansOut', 1 ,, 'Ysave',1
### alpha —Global trimming level.scalar.
alpha is a scalar between 0 and 0.5. If alpha=0 (default) tkmeans reduces to kmeans.
Example: 'alpha', 0.05
Data Types: single | double
### plots —Plot on the screen.scalar, char, | struct.
- If plots=0 (default) no plot is produced.
- If plots=1, the components merged are shown using the spmplot function. In particular:
* for v=1, an histogram of the univariate data.
* for v=2, a bivariate scatterplot.
* for v>2, a scatterplot matrix.
When v>=2 plots offers the following additional features (for v=1 the behaviour is forced to be as for plots=1):
- plots='contourf' adds in the background of the bivariate scatterplots a filled contour plot. The colormap of the filled contour is based on grey levels as default.
This argument may also be inserted in a field named 'type' of a structure. In the latter case it is possible to specify the additional field 'cmap', which changes the default colors of the color map used. The field 'cmap' may be a three-column matrix of values in the range [0,1] where each row is an RGB triplet that defines one color.
Check the colormap function for additional informations.
- plots='contour' adds in the background of the bivariate scatterplots a contour plot. The colormap of the contour is based on grey levels as default. This argument may also be inserted in a field named 'type' of a structure.
In the latter case it is possible to specify the additional field 'cmap', which changes the default colors of the color map used. The field 'cmap' may be a three-column matrix of values in the range [0,1] where each row is an RGB triplet that defines one color.
Check the colormap function for additional informations.
- plots='ellipse' superimposes confidence ellipses to each group in the bivariate scatterplots. The size of the ellipse is chi2inv(0.95,2), i.e. the confidence level used by default is 95%. This argument may also be inserted in a field named 'type' of a structure. In the latter case it is possible to specify the additional field 'conflev', which specifies the confidence level to use and it is a value between 0 and 1.
- plots='boxplotb' superimposes on the bivariate scatterplots the bivariate boxplots for each group, using the boxplotb function. This argument may also be inserted in a field named 'type' of a structure.
REMARK - The labels<=0 are automatically excluded from the overlaying phase, considering them as outliers.
Example: 'plots', 1
Data Types: single | double | string
### tkmeansOpt —tkmeans optional arguments.structure.
Empty structure (default) or structure containing optional input arguments for tkmeans.
See tkmeans function.
Example: 'tkmeansOpt.reftol', 0.0001
Data Types: struct
### tkmeansOut —Saving tkmeans output structure.scalar.
It is set to 1 to save the output structure of tkmeans into the output structure of dempk. Default is 0, i.e. no saving is done.
Example: 'tkmeansOut', 1
Data Types: single | double
Example:
Data Types:
### Ysave —Saving Y.scalar.
Scalar that is set to 1 to request that the input matrix Y is saved into the output structure out.
Default is 0, i.e. no saving is done.
Example: 'Ysave',1
Data Types: double
## Output Arguments
### out — description Structure
Structure which contains the following fields
Value Description
PairOver
Pairwise overlap triangular matrix (sum of misclassification probabilities) among components found by tkmeans.
mergID
Label for each unit. It is a vector with n elements which assigns each unit to one of the groups obtained according to the merging algorithm applied.
REMARK - out.mergID=0 denotes trimmed units.
tkmeansOut
Output from tkmeans function. The structure is present if option tkmeansOut is set to 1.
Y
Original data matrix Y. The field is present if option Ysave is set to 1.
## References
Melnykov, V., Michael, S. (2017), "Clustering large datasets by merging K-means solutions". Submitted.
Melnykov, V. (2016), Merging Mixture Components for Clustering Through Pairwise Overlap, "Journal of Computational and Graphical Statistics", Vol. 25, pp. 66-90. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5129867196083069, "perplexity": 16790.220829584618}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-05/segments/1579250590107.3/warc/CC-MAIN-20200117180950-20200117204950-00241.warc.gz"} |
https://www.physicsforums.com/threads/integrate-e-pi-2-x-2.220622/ | # Homework Help: Integrate e^(-pi^2*x^2)
1. Mar 8, 2008
### Gear300
How would I integrate e^(-pi^2*x^2) from -infinite to infinite? I know that the integral of e^(-x^2) from -infinite to infinite is sqr(pi), in which sqr is square root.
2. Mar 8, 2008
### CompuChip
In general once can prove that
$$\int_{-\infty}^{\infty} e^{-\alpha x^2} \, \mathrm{d}x = \sqrt{\frac{\pi}{\alpha}},$$
for $\alpha > 0$ (and even $\alpha \in \mathbb{C}, \operatorname{Re}(\alpha) > 0$).
Then if you take $\alpha = 1$ or $\alpha = \pi^2$ you will get either of the integrals in your post.
3. Mar 8, 2008
### Gear300
I see...thank you.
4. Mar 8, 2008
### Schrodinger's Dog
Actually, I can see in this case that a=b so b-a=0 and therefore
$$\int_a^b e^{-\pi x^2}\,dx \rightarrow \int_{-\infty}^{\infty} e^{-\pi x^2}\,dx=1$$
But that's probably beside the point. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9907703399658203, "perplexity": 5622.661235989811}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221213405.46/warc/CC-MAIN-20180818060150-20180818080150-00525.warc.gz"} |
https://link.springer.com/article/10.1007%2Fs00193-004-0237-2 | Shock Waves
, Volume 14, Issue 1–2, pp 73–82
Multiple pulsed hypersonic liquid diesel fuel jetsdriven by projectile impact
• K. Pianthong
• K. Takayama
• B. E. Milton
• M. Behnia
Original article
Abstract.
Further studies on high-speed liquid diesel fuel jets injected into ambient air conditions have been carried out. Projectile impact has been used as the driving mechanism. A vertical two-stage light gas gun was used as a launcher to provide the high-speed impact. This paper describes the experimental technique and visualization methods that provided a rapid series of jet images in the one shot. A high-speed video camera (106 fps) and shadowgraph optical system were used to obtain visualization. Very interesting and unique phenomena have been discovered and confirmed in this study. These are that multiple high frequency jet pulses are generated within the duration of a single shot impact. The associated multiple jet shock waves have been clearly captured. This characteristic consistently occurs with the smaller conical angle, straight cone nozzles but not with those with a very wide cone angle or curved nozzle profile. An instantaneous jet tip velocity of 2680 m/s (Mach number of 7.86) was the maximum obtained with the 40$$^\circ$$ nozzle. However, this jet tip velocity can only be sustained for a few microseconds as attenuation is very rapid.
Keywords:
multiple pulsed jet hypersonic diesel fuel jets jet shock wave
Authors and Affiliations
• K. Pianthong
• 1
• K. Takayama
• 2
• B. E. Milton
• 3
• M. Behnia
• 3
1. 1.Department of Mechanical Engineering, Faculty of EngineeringUbon Ratchathani UniversityThailand
2. 2.Interdisciplinary Shock Wave Research Center, Institute of Fluid ScienceTohoku UniversitySendaiJapan
3. 3.School of Mechanical and Manufacturing EngineeringThe University of New South WalesSydneyAustralia | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5679482817649841, "perplexity": 3962.4643782072867}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-34/segments/1502886102309.55/warc/CC-MAIN-20170816170516-20170816190516-00110.warc.gz"} |
https://www.appsweb.kr/2664 | 알림
## The navigation bar will stay at the top of the page while scrolling
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
Some text some text some text some text..
비즈
쇼핑
결제
마케팅
관리
도움말
A/S문의
공지사항
업데이트
이벤트
###### Overview
회사연혁
오시는 길
상호명 : 애드리빙
서울시 마포구 마포대로 63-8 삼창프라자빌딩 1539호
사업자등록번호 : 106-04-80687 조회하기
통신판매업신고번호 : 제 2015-서울용산-00950 호
T.1566-5733 F.02-6499-3299 [email protected]
운영시간 : 평일 AM 10:00 ~ PM 18:00(공휴일 휴무)
점심시간 : AM 11:30 ~ PM 1:00 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9986629486083984, "perplexity": 29615.19728313925}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572220.19/warc/CC-MAIN-20220816030218-20220816060218-00119.warc.gz"} |
http://flexpearls.blogspot.com/2009/01/how-to-build-datavisualizationswc-from.html | ## Monday, January 19, 2009
### How to build datavisualization.swc from the source ?
Here are steps to build datavisualization.swc from the source that gets unzipped into a fbpro directory in FlexBuilder when a valid license is provided.
Setup
4. Set environment variables. Go to Control Panels > System > Advanced > Environment Variables
• Set JAVA_HOME to the path to the jdk directory. Add path of ant1.7 to PATH. For example, C:\ant1.7.0\bin (you will already have a PATH, multiple entries are separated by semicolons)
• Add path of cygwin to PATH. For example, C:\cygwin\bin
Steps:
1. Add files build.properties and build.xml(attached) to location of datavisualization directory. For example, C:\Program Files\Adobe\Flex Builder 3\sdks\3.2.0\fbpro\projects.
3. Unzip inside_ datavisualization.zip. The build.xml and build.properties files should be copied inside datavisualization folder.For example, C:\Program Files\Adobe\Flex Builder 3\sdks\3.2.0\fbpro\projects\datavisualization.
4. Make changes regarding location of sdk and output swcs to files build.properties and datavisualization\build.properties.
5. At the cygwin prompt, go to the datavisualization. For example C:\Program Files\Adobe\Flex Builder 3\sdks\3.2.0\fbpro\projects\ datavisualization.
6. Run ant main to build datavisualisation.swc and datavisualization_rb.swc for en_US .
7. Run ant main_with_ja_JP to build datavisualisation.swc and datavisualization_rb.swc for en_US and ja_JP.
Note: Place the datavisualization.swc at sdk\frameworks\libs and datavisualization_rb.swc at sdk\frameworks\locale.
Tom said...
Is there any way to get beta DMV build like Flex SDK?
Sreenivas said...
It is not available as of now.
Wayne Babich said...
Is it now required that I build the datavisualization swc files myself?
I just downloaded the flex 3.2.0 (I previously had 3.1.0), and found that it doesn't contain the libs/datavisualization.swc and locale/*/datavisualization_rb.swc files that were contained in 3.1.0.
Is this intentional?
Is it now required that I build the datavisualization swc files from source?
Have the sources changed between 3.1.0 and 3.2.0?
I tried to follow the instructions contained in the posting, but could not find the build.xml file that was supposed to be attached.
I feel like I must be attacking this problem the hard way. Is there an easy way to simply download flex 3.2 including datavisualization in one or two simple steps?
BTW: I have a paid license key, so that's not an issue.
Tom said...
Wayne, you should download Flex Builder 3.0.2, it will install Flex 3.2 alone with DMV. Delete your existing Flex 3.2 SDK just in case.
Frank said... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.91396164894104, "perplexity": 15060.14804371757}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794864648.30/warc/CC-MAIN-20180522073245-20180522093245-00404.warc.gz"} |
http://ibrg.pc-tastschreiben.de/how-to-solve-periods-problem.html | .article-body a.abonner-button:hover{color:#FFF!important;}
I wish to solve the following system of PDEs for h1, h2. It's not quite as bad as it seems, because in nature, women would experience periods quite rarely – probably no more than a few tens of times in their lives between lactational amenorrhea and pregnancies**. All of the following variables are fundamental to solving interest problems. Physics Problems ; Physics Problems have a special place in Physics Learning. J H OMla Adke T LwqiUtphO eIGnfpi Yn0i 5t ZeX 4Avl QgRe2bIr SaR f1 W. When you were young, anticipating your very first period, you were excited by that passage into womanhood. Other Ways to Survive the Winter. Draw a model if you need to. A geostationary satellite is a satellite in geostationary orbit, with an orbital period the same as the Earth's rotation period. So in order to solve the problems of this World you really need to evolve or replace all the bad, sometimes terrible and often outdated dominant ideas of this World, from which these problems are ultimately derived in the first place and from which they may also have their maintenance. of Administrative Services for payment around 5:30 p. Students will also assess how successful they were in solving these problems. Both the rate and the number of periods are consistent, so we can now solve for the unknown present value PV. Homeopathic medicine Calcarea Carb helps such women in reducing the excessive weight gain very efficiently. Hardware problems are hard to diagnose and solve. NAME DATE PERIOD Lesson 3-1 PDF Pass Chapter 3 9 Glencoe Algebra 2 3-1 Word Problem Practice Solving Systems of Equations 1. Also, aim for an intake of half a teaspoon of cinnamon (mixed in warm lemon water with honey or in a glass of (almond) milk). Our problem solving pages provide a simple and structured approach to problem solving. Distance Problems - algebra word problems involving distance, rate (speed) and time, How distance problems are solved: Traveling At Different Rates, Traveling In Different Directions, Given Total Time, Wind and Current Problems, examples with step by step solutions, speed word problem, distance word problems, speed word problems. Polygons and Angles NAME DATE PERIOD Lesson 4 Problem-Solving Practice For Exercises 1–6, use the formula S = (n – 2)180° to solve. Reconstruction was the period after the American Civil War in which attempts were made to solve the political, social, and economic problems arising from the readmission to the Union of the 11. We will solve for the interest rate first since it is a more common need and also a bit easier mathematically. However, if your financial situation improves by the time you need to renew your mortgage, it may make more sense to shorten your mortgage amortization period. Small learners need more guidance. When faced with a problem, what do you do to solve it? This assignment asks you to apply a six-step to problem solving process to a specific problem scenario. Quantitative research aim to measure the quantity or amount and compares it with past records and tries to project for future period. A simple harmonic motion system force is experienced by the Hooke’s law. Let go of the past, and solve one problem at a. A lifetime of learning Get started with Brilliant’s course library as a beginner, or dive right into the intermediate and advanced courses for professionals and lifelong learners. PDF | In this paper we show how to bypass the usual difficulties in the analysis of elliptic integrals that arise when solving period problems for minimal surfaces. One weekend, Nate compared his history homework to his younger sister Caroline’s social studies homework. If a problem is the responsibility of, or can be fixed by one person, a group meeting is likely a waste of time. So if you want to induce periods, avoid salty and heavy foods. Evaluating the socially optimal size, scope and organizational structure of financial firms is a complicated business, and so is establishing a viable transition path to a system of much smaller firms. HOW TO DEAL WITH PROBLEMS AFFECTING ADOLESCENTS Adolescence, according to Erik Erikson's stages of human development, is the stage marked between puberty and adulthood, usually during ages thirteen to nineteen, though the age bracket may vary depending on different cultures, for example, in the United States; an adolescent is understood to be any person between ages thirteen to twenty-four. Let go of the past, and solve one problem at a. Nearest ten → To round to the nearest ten, observe that the digit in the ones place is. How to Use Root Cause Analysis. For example the Earth takes 24 hours to spin once around its axis. The half - life period of the reaction is :. They readily take advantage of others, and tend to be quite arrogant. We have the ability to make calculations and solve problems, even in situations we have never. For more about the 3 Secrets (and 3 Solutions), download my free e-book by going HERE. I was able to do this by motivating the senior engineering team to brainstorm a technologically innovative solution that would solve the customer's issues with fewer development hours on. At the same time to understand physics we need to solve as many physics problems as possible. 'y in politics time is one of the most precious resources, and a problem delayed can be a problem half solved'. Learn how to do just about everything at eHow. One of the ways to measure your flow to find out if you have a heavy period is to use a menstrual cup. How to solve the I d. So, in this case the average function value is zero. Solving for the Interest Rate. Homework Practice and Problem-Solving Practice Workbook Contents Include: • 120 Homework Practice worksheets- one for each lesson • 120 Problem-Solving Practice worksheets- one for each lesson to apply lesson concepts in a real-world situation Homework Practice and Problem-Solving Practice Workbook. Savings Bond today and earned 6. 5- The perimeter of a rectangular floor is 90 feet. 65 × 103 about 3. Problem-Solving Practice. Menstrual problems like cramps or the cluster of symptoms known as PMS can be treated through a variety of herbal methods. At the end of year one she buys three more shares at $89 per share. If you like this Site about Solving Math Problems, please let Google know by clicking the +1 button. Remember what consumer theory was all about: "The consumer chooses her most preferred bundle from her budget set". Whether you. if your periods are irregular and you want to get them every month on time, you should go to the doctors and ask to be put on the pill. 6% APR compounded monthly on your savings account. From the viewpoint of solving the sustainability problem, here's the most important step of them all in the Kuhn Cycle. Press release: Endometriosis UK & DiaryDoll – raising awareness to solve your period problems Wednesday, March 05, 2014 As Endometriosis UK launches its Awareness Week for 3rd – 9th March 2014, calling on women to know that: ’ It’s ok to talk. Define a variable and write an equation. If this continually becomes an issue, then there are two possible solutions. To solve a problem, you must first be willing to accept the problem by acknowledging that the problem exists, identifying it, and committing yourself to trying to solve it. Quizlet flashcards, activities and games help you improve your grades. com is your go-to source for all things science. The rules say that the average age of the pair of players on each side must be ten years old or younger. With a WMS that's easy-to-use and easy. Many word problems will give rise to systems of equations --- that is, a pair of equations like this: You can solve a system of equations in various ways. Helping women solve their period problems so they can feel great every day of the month. Revolutionary technology to learn ‘How healthy are your period’. All FFS claims are processed when submitted and approved claims are sent to Dept. Initial Value Problems for Growth and Decay. It is the net present value of all future cash flows for a particular investment. 436 european politicalscience: 9 2010 eu enlargement – how transitional periods solve problems. Now practice on this Algebra (Two Steps to Solve) Worksheet and then check your answers on the page after. 1 Deriving rst-order conditions: Certainty case We start with an optimizing problem for an economic agent who has to decide each period how to allocate his resources between consumption commodities, which provide instantaneous utility, and capital commodities, which provide production in the next period. You can help protect yourself from scammers by verifying that the contact is a Microsoft Agent or Microsoft Employee and that the phone number is an official Microsoft global customer service number. The titles of short works like sonnets, short poems, songs, chapters, and short stories are normally placed in quotation marks "like this. Pendulum Problems Examples using Huygen's Law of for the period of a Pendulum. To tackle this great problem of web accessibility, I would rather embrace unification within the community instead of competition, which makes us even more fragmented. Electrolysis. Toni spent the day at the mall. Download free on Google Play. Only use the calculator in the last step and round-off only once. Tisha wants to go to Corpus Christi this weekend. With 20 billion pads and tampons going to landfill every year, getting your period to go zero waste is an easy way to make a big impact. What percent of the substance is left after 6 hours? So let's make a little table here, to just imagine what's going on. if your periods are irregular and you want to get them every month on time, you should go to the doctors and ask to be put on the pill. I was diagnosed with hypothalamic amenorrhea in February when my period didn’t return after 10 years on the pill. The amounts that must be deposited now to permit withdrawals of 1 at the beginning of each period are contained in the. It could be the result of some intensive process, and you just need to wait it out. Problem: Calculate the value of a bond with a maturity value of$1,000, a 5% coupon (paid semi-annually), five years remaining to maturity, and is priced to yield 8%. Menopause does not need to be diagnosed, and usually irregular periods are not a problem, but if you have other symptoms and your irregular periods are painful, it is a good idea to talk to a doctor. Solve each equation below. Problem Solving 11: Interference and Diffraction OBJECTIVES 1. True The famous newspaper journalist H. Heavy periods, no periods, painful periods, spotting -- find out when it's time to call your doctor. Guidelines to Problem Solving and Decision Making (Rational Approach) Much of what people do is solve problems and make decisions. मासिक पाळीबाबत यथावकाश तिला हे कळलं, की आपण जे अनुभवलं ते संकट, आजार, जखम किंवा शिक्षा असं काहीही नसून ती एक अत्यंत. The TI BAII Plus Professional is a fairly easy to use financial calculator that will serve you well in all finance courses. Brilliant guides you through problem solving strategies and challenges you to think outside the box. Solving for the interest rate in a lump sum problem is far more common than you might imagine. The diameter of the buoy is 0. The current price of the stock is $80. , Princeton University Press, 1957, ISBN -691-08097-6. courses than do other topics. View Homework Help - U1L03 Activity Guide - Using the Problem Solving Process (2018). -Future value. Every second girl face these type of problm plzz do like and share that aware girls and stay hppy ☺️ that they never face any proplem poonam. Problem State the amplitude, period, vertical shift, phase shift, and reflection for the sinusoid y = -2 sin (2 x - p /4) - 3. On Saturday morning, Ernesto rode his bike to his friend’s house and rode back home later on. Sample Problem How much '"K will be left in a 320 g sample after 62 h? Step 1: Look up the half life In Table N, the table of Selected Radioisotopes 12. q f 7M yaXdfe C 7wpi4tlhI tI znfci 3n Ii 3t6em LGKeLo 8mfeitkr qyo. Masse’s biology class is conducting an experiment to record the growth of a certain kind of bacteria. Too Little Time With Students is one of Several Key Problems that Flipped Learning can Help to Address The topic for this week’s Slack Chat and next week’s #Flipblogs “extended Twitter chat” is the same: “What problem(s) has Flipped Learning helped to solve for you?” (Learn more about the Slack Chat here, and about the #Flipblogs […]. Period problem solution in hindi : मासिक धर्म का उपचार - मासिक चक्र किसी भी लड़की की जिन्दगी का एक अहम् हिस्सा है| Jaane yaha period se judi har pareshani ka gharelu ilaj period jaldi aane ke upay, period late aane ke upay, gharelu nuskhe for irregular periods, maasik dharm. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. 156 comments. There is a "trick" to doing work problems: you have to think of the problem in terms of how much each person / machine / whatever does in a given unit of time. NAME _____ DATE _____ PERIOD _____ Lesson 3 Problem-Solving Practice Writing Equations 1. Free tutorials and problems on solving trigonometric equations, trigonometric identities and formulas can also be found. For many it’s hard enough to get by while studying and working a part-time job, but the high costs of period products in the UK add another significant cost to students’ already tight budget. Jokes apart, obviously, there are many types of Facebook login problems that people generally encounter. At the beginning of the current period, Fassi Corp. Before you try some easy strategies to get her back in the litter box, have her checked out by a veterinarian to rule out a health problem. When you are solving problems for distance, rate, and time, you will find it helpful to use diagrams or charts to organize the information and help you solve the problem. For some girls, getting their first period is a huge milestone. Although problem-solving is often identified as its own separate skill, there are other related skills that contribute to this ability. The NPV is the PV (present value) of all cash inflows minus the PV of all cash outflows. The answer would be 11,025. How to solve irregular periods problem naturally in Tamil | Home remedy for irregular periods | Irregular periods treatment | Overcome irregular periods | Make in Kitchen coconut milk ,cotton seed. Mencken once said, "To every complex question there is a simple answer—and it's clever, neat, and wrong!". Your parents took your family out to dinner. RE: How to solve constipation without pills? Ive been constipated for a while and was wondering how i could go without pills maybe a kind of food or drink because im sick of this. Although problem-solving is often identified as its own separate skill, there are other related skills that contribute to this ability. For many it’s hard enough to get by while studying and working a part-time job, but the high costs of period products in the UK add another significant cost to students’ already tight budget. Problems solving for N (number of periods) on HP I2c 10-02-2017 11:57 AM - edited 10-02-2017 12:19 PM Also of note is that in EVERY exam that allows the 12C, the 12C answer is acceptable and not incorrect. For example the Earth takes 24 hours to spin once around its axis. ’s for up. Physics Problems ; Physics Problems have a special place in Physics Learning. January 10, 2014 Solving with sinusoids Modeling with sinusoidal functions: Word Problems 1. Joe’s friends are going to climb the climbing wall and have invited Joe to go with them. Trying to solve a complex problem alone however can be a mistake,. Daily estimated values for each machine are reported over a period of time. Problem-Solving Practice Compute with Scientifi c Notation Region Amount Raised ($) East 1. At most facilities, you will find that 20% of your doors will be responsible for 80% of your DFO alarms. Solve and Write Addition Equations. For example, the second hand on a clock completes one revolution every 60 seconds and therefore has an angular frequency of 1 / 60 Hz. When you solve the underlying imbalances, your body no longer needs to use pain to send you messages. How many miles per gallon did Ron get from his new truck?. Problem Solving and Data Analysis questions include both multiple-choice questions and student-produced response questions. Basically, the interviewer wants to get an idea of your judgment and decision making skills, as well. Notice in the formula that the mass of a simple pendulum's bob does not affect the pendulum's period; it will however affect the tension in the pendulum's string. re: 7 Wireless Router Problems And How To Solve Them I am having the exact same issue. A student is wondering,” How do I start? From where do I start? What formula should I use? “ These books try to answer these and other questions. From the viewpoint of solving the sustainability problem, here's the most important step of them all in the Kuhn Cycle. Constant velocity means zero acceleration. Toni spent the day at the mall. But a production planning problem exists because there are limited production resources that cannot be stored from period to period. q f 7M yaXdfe C 7wpi4tlhI tI znfci 3n Ii 3t6em LGKeLo 8mfeitkr qyo. Problem State the amplitude, period, vertical shift, phase shift, and reflection for the sinusoid y = -2 sin (2 x - p /4) - 3. Students will investigate who the Progressive reformers were, what they believed in, what problems they hoped to solve, and what methods they used. Joe is downloading songs from the Internet. Everyone, Today I am Going to share these amazing home remedies for Instant Get Solve Periods Problem. Period problem solution in hindi : मासिक धर्म का उपचार - मासिक चक्र किसी भी लड़की की जिन्दगी का एक अहम् हिस्सा है| Jaane yaha period se judi har pareshani ka gharelu ilaj period jaldi aane ke upay, period late aane ke upay, gharelu nuskhe for irregular periods, maasik dharm. Teenage Periods – What You Need to Know. where $${P\leq \sqrt{N}}$$ and $${M \ll N}$$, and where M is assumed known. Here are some popular behavioral questions related to the competency of problem solving: • Tell me about a situation where you had to solve a difficult problem. True The famous newspaper journalist H. 436 european politicalscience: 9 2010 eu enlargement - how transitional periods solve problems. Let’s just jump into the examples and see how to solve trig equations. Constant velocity means zero acceleration. The ions are "forced" to undergo either oxidation (at the anode) or reduction (at the cathode). Java applets are used to explore, interactively, important topics in trigonometry such as graphs of the 6 trigonometric functions, inverse trigonometric functions, unit circle, angle and sine law. The interest rate after the introductory period is 27. Hw can i regularise it? My age is 27, Unmarried. The tannins in it strengthen the uterine muscles. An Embargo on Dissertations Will Not Solve the Bigger Problem From one perspective, the American Historical Association’s call to allow the “embargo” of dissertations by new Ph. How to Solve This webpage has a redirect loop problem. Already i consulted with some doctors regarding this. In the first problem, it explains how to calculate the frequency and period of a simple pendulum. Set options for the problem to have no display and a plot function that displays the first-order optimality, which should converge to 0 as the algorithm iterates. Determining Reaction Rates; Rate Laws and Order of a Reaction; Determining Rate Laws from Rate versus Concentration Data (Differential Rate Laws) Determining Rate Laws from Graphs of Concentration versus Time (Integrated Rate Laws). Simple Pendulum Equations Calculator Science Physics Oscillations Design Formulas. Regular periods are a sign that your body is working normally. Her distance can be calculated by using the equation d = 50t, where d is the distance she travels and t is the time in hours. Is the secret to getting rich winning the lottery? No! Compound interest and patience are!. Each golfer’s cost is $1. According to Merger, the problem-solving process involves 10 steps, which can be expanded into learning strategies to enable students with math disabilities to be more effective in solving word problem. The amount of time it takes a business to run out of cash depends on a number of factors. And it could do this without actually solving the problem of system risk externalities that aren’t related to balance sheet size. Inflation Protection from REITs: Solving a Growing Problem 7/16/2018 | By Brad Case Inflation has been mild for several years, but things have started to change: the Bureau of Labor Statistics reported on July 12 that the Consumer Price Index had increased for the sixth month in a row. As you will see, it is very important to do this step after step 3. ©V l2 a0N1 b27 iK bu stva r ASyoOf6t Uw6aurfe r 8LFLAC x. 8 0 HAbl plC mrLilglh tWsU yrUe js pe Criv Ke0d O. Check Whether Facebook is Down or It is Local Problem. For instance, Ruby Cup Medium holds 24 ml of menstrual fluid, which is 3x more than a super tampon. For example, if Cole drives his car 45 km per hour and travels a total of 225 km, then he traveled for 225/45 = 5 hours. A simple harmonic motion system force is experienced by the Hooke's law. Since acceleration due to gravity is constant on Earth, the only dependent fac- tor is the length of the pendulum. How Reusables Solve Your Period Problems Okay, okay - you get it. mostUnique - Solve a Problem - Practice-It. Simple Pendulum Equations Calculator Science Physics Oscillations Design Formulas. If you can’t resolve a problem with a company, you may be able to try an alternative dispute resolution program. Every second girl face these type of problm plzz do like and share that aware girls and stay hppy ☺️ that they never face any proplem poonam. Genetic Algorithm to Solve Multi-Period, Multi-Product, Bi-Echelon Supply Chain Network Design Problem: 10. The first step to effectively translating and solving word problems is to read the problem entirely. Calculating the value of a bond. you'll be well set up to take the panic out of peak periods. Solving for the number of periods can be achieved by dividing FV/P, the future value divided by the payment. Permalink problems can be especially difficult to solve. And everything became rosy once again:. Skin problems can result from an internal imbalance, often in the gut. A ranch in Wyoming is approximately 825,000 acres. Guidance involves the art of helping boys and girls in various aspects of academics, improving vocational aspects like choosing careers and recreational aspects like choosing hobbies. Of course there are exceptions when it can be a sign of problems but in the vast majority of cases it is a variation of normal. 5% per year. To solve this problem, use the formula for future value with continuous compounding. Often, the teacher's already wise to your child's preschool problem and is working to solve it. Now practice on this Algebra (Two Steps to Solve) Worksheet and then check your answers on the page after. In any case, here's how you can handle iPhone battery life problems. 5 value which is at $$2 \pi$$. Suppose that a sum. Also, your hormones influence menstruation. The main reason behind this is that sitting, in an office chair or in general, is a static posture that increases stress in the back, shoulders, arms, and legs, and in particular, can add large amounts of pressure to the back muscles and spinal discs. Other Ways to Survive the Winter. Suppose that a particle of mass 0. Solving The Drug Patent Problem. There is a problem, and most of the time you try to fix the symptoms, but almost certainly it will return. Children develop skills in five main areas of development: Cognitive Development This is the child's ability to learn and solve problems. Thus, the highest attainable utility is (24) Now consider reducing consumption by some small amount in period 1, investing that so that it grows to in period 2, and then consuming it in period 2. Simply answer 18 questions and see your result instantly. These symptoms or situations may indicate that you may have a problem getting pregnant - the information is on the Victorian Government website 'Better Health Channel': Having irregular periods - this may indicate problems with ovulation or due to Polycystic Ovarian Syndrome. by Rachel Garnham | Jun 24, 2019 | Period Problem Solving. should be 448 but not working it goes back to invoice no. Solve and Write Addition Equations. If your periods are irregularly heavy it is important you are getting enough iron, which is a necessary mineral for healthy blood that can transport oxygen throughout the body. 055 × 104 dollars 9. Lin is tracking the progress of her plant’s growth. Suppose that a particle of mass 0. Don't try to solve a problem the customer sees as low priority or unimportant. Don't start trying to solve anything when you've only read half a sentence. Sandra is eight years old. She is to pay it back equal monthly payments over a 5-year period. There are two ways to calculate the payback period, which are: Averaging method. He found that for every 2 1− pages he had to read for 3. Question 974333: Need help on how to solve this problem. English (US) · Español · Português (Brasil) · Français (France) · Deutsch. How To Solve Galaxy S8 And Galaxy S8 Plus Auto Correct Issue Posted by David Covington on March 30, 2017 Despite the fact that the Auto Correct feature of your Samsung Galaxy S8 or Galaxy S8 Plus was meant to help, it can also become an issue at times. Hope this video is really helpful for you guys. It's defined as the reciprocal of frequency in physics, which is the number of cycles per unit time. The TI BAII Plus is a fairly easy to use financial calculator that will serve you well in all finance courses. Future value of an ordinary annuity of 1 table. Accept Reject Read More. Constant Acceleration Motion Calculator Online program for calculating various equations related to constant acceleration motion. When i was in class 9,i started to have irregular menses. NET and SQL Server? In this case the issue is "The timeout period elapsed prior to obtaining a connection. An Embargo on Dissertations Will Not Solve the Bigger Problem From one perspective, the American Historical Association’s call to allow the “embargo” of dissertations by new Ph. NAME DATE PERIOD Problem-Solving Practice Solve and Write Multiplication Equations For Exercises 1-3, use the table below. 05^2, which equals 10*000(1. Rate of change in position, or speed, is equal to distance traveled divided by time. However, having a ballpark idea of the amount of your income and debt burden is not enough to tackle your debt problem. Assuming that the problem has been solved up to period t + 1 (and thus assuming that we have an approximated c t +1 (m t +1)), our solution method essentially involves using these two equations in succession to work back progressively from period T − 1 to the beginning of life. NAME DATE PERIOD Problem-Solving Practice Solve and Write Multiplication Equations For Exercises 1-3, use the table below. Light periods are a sign of low estrogen, heavy periods are a sign of excess estrogen. our last invoice no. Before starting these examples you might want to refresh you memory on solving these problems. If the two parents in the figure exert upward forces of 18 N on the left end of the plank and 71 N on the right end, (a) how much does the child weigh? (b) How far is the child from the left end of the plank? The plank has a length of 2. How To Solve Galaxy S8 And Galaxy S8 Plus Auto Correct Issue Posted by David Covington on March 30, 2017 Despite the fact that the Auto Correct feature of your Samsung Galaxy S8 or Galaxy S8 Plus was meant to help, it can also become an issue at times. The National Weather Service has a Wind Chill Temperature (WCT) index. Permission is granted to reproduce for classroom use. the current inventory xt) and prior actions on the part of the adversary, and chooses ut appropriately. Divide the annualized expected cash inflows into the expected initial expenditure for the asset. When i was in class 9,i started to have irregular menses. This guided walk through aims at providing the same for various connection errors that connecting to SQL Server. For the HP12C to solve problems involving leases or annuities due, it must be in Begin mode. 80 Course 3 • Chapter 5 Triangles and the Pythagorean Theorem. Please show steps on how to write the linear functionThank You :) Write the linear function for the real-world situation described. By Stephanie Watson. Technical debt you can pay down. If you know any 3 of those things, you can plug them in to solve for the 4th. Sandra is playing in a tennis doubles tournament. Hereford The quote by Jean De La Bruyere: "Life is a tragedy for those who feel, and a comedy for those who think," may seem a bit radical, however, according to the premise of cognitive psychology, what you think is what you feel. 04 mol l-1 s-1 at 10 seconds and 0. I just feel like the car has electrical problems and that is what causes the hesitation. l have irregular periods problem. Determining Reaction Rates; Rate Laws and Order of a Reaction; Determining Rate Laws from Rate versus Concentration Data (Differential Rate Laws) Determining Rate Laws from Graphs of Concentration versus Time (Integrated Rate Laws). Earth's orbit - Changes in the Earth's orbit (called Milankovitch cycles) can cause the Earth to be closer to the Sun (warmer) or further from the Sun(colder). The Simple But Effective Way to Solve Problems Better Wrestling with a tough choice? This simple strategy will give you clarity. For more about the 3 Secrets (and 3 Solutions), download my free e-book by going HERE. In order to solve the problem in one step, we note that the list price is 100% of the list price and the list price is being reduced by 30% of the list price. 5% per year. For some students, solving problems on ages is never being easy and always it is a challenging one. 2 Problem Solving Strategy Problem Solving Strategy In general, single payments will be simple or compound interest – Look for hints as to whether simple or compound interest is used – Shorter time periods are often (but not always) simple interest Continuing payments involve annuities 3. Identify the right problem by asking the right questions and observing. Remember, mean = average. Designate and as the optimal levels of consumption in this problem, the levels that solve the maximization problem under some set of circumstances. Use the information in the table for 1–3. Train Your Brain to Focus. Parsley contains Apiol and Myristicin which stimulates the. ©C w240N172 X YK7uBt Sa4 xS otfst Twza sr je Q 1L0LMCP. Physicists, engineers and astronomers, study and work with. This is the same as subtracting 5 from each side. Solve Problems Involving Profit and Loss (8) Solve Problems Involving Simple Interest (9) Solve Problems Involving Compound Interest (10) Solving Problems Involving Compound Interest Non-Annual Compounding (VCE Unit 1) Numbers 2-6. How to Solve for the Original Amount of an Exponential Function. Problem solving meetings should be oriented around issues that affect and are only resolvable by the team. Simply say "time" or "period. Because of their widespread use, we will use present value tables for solving our examples. Regarding this machine, we use Japanese imported alloy cutting blade,. Whether you. A common assumption (for simplicity, not realism) is that , which is equivalent to assuming that the utility function is logarithmic: 2. About how many of the available board games cost less than$10? 6. Revolutionary technology to learn 'How healthy are your period'. problems will require different formats; however it is extremely rare that you would only be asked to record your answer without showing any work. The second problem. Using Multiplication property of Equality. aniyamit mahavari aniyamit period how to regular periods naturally in hindi how to solve periods problem in hindi irregular menstruation natural treatment in hindi. The problem is i have a bad memory i forgrt what i study in a short tme period. How many periods of time, each 1/6 of an hour long, does a 10-hour period of time represent?. • Click on NPER • Now, enter the values in the dialogue box: Therefore, number of compounding periods is 18 approximately. If your periods are irregular, ask your doctor to measure the hormones in your blood. In many cases, one of these variables will be equal to zero, so the problem will effectively have only four variables. 05^2, which equals 10*000(1. l have irregular periods problem. Before we get started, an easy tip to know if your quadcopter is not arming due to the pre-arm safety checks, you can look at your flight controller when you try to arm. If this continually becomes an issue, then there are two possible solutions. Since the period is , you can verify that the graph also crosses the x-axis again at and at , 17. Thus, the highest attainable utility is (24) Now consider reducing consumption by some small amount in period 1, investing that so that it grows to in period 2, and then consuming it in period 2. In many of the examples below, I'll use the whole equation approach. A simple harmonic motion system force is experienced by the Hooke's law. Permalink problems can be especially difficult to solve. Section 1-4 : Solving Trig Equations. docx from ENG 101 at Trevor Browne High School. The question is how is this bundle chosen?. To solve these problems, just start at the x-axis and look for the first time that the graph returns to that 'height. I) determine the overall order and solve equation for rate constant. Example: An initial investment of Rs. e a fM 5a jd yex Qw BiOtRhE QI2n 3fFi ln xictfe h PA Tl gbeub tr da i q1 e. If they worked together how long would it take them? 2) It takes Heather seven hours to pour a large. To solve this problem, use the formula for future value with continuous compounding. Try the entered exercise, or type in your own exercise. Refer to Appendix F for more information. This research is based on numeric figures or numbers. If this happens, you may have to take more steroid medicine. (b) Plot the solution for a time period long enough so that you see the ultimate behaviour of the graph. Suppose that a particle of mass 0. Designate and as the optimal levels of consumption in this problem, the levels that solve the maximization problem under some set of circumstances. They believe they are special and deserve special treatment, regardless of the problems this creates for others. How to solve this problem- The rate of first order reaction is 0. We had horrendous problems with our wooden kitchen worktops feeling sticky, they had been previously treated with Danish oil. Section 4: Using a Financial Calculator Tab 3: Examples Example 1 What is the future value of \$500 deposited three years ago? The interest rate is 6% monthly compounding. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 2, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5890986323356628, "perplexity": 1658.8070760623875}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496667262.54/warc/CC-MAIN-20191113140725-20191113164725-00036.warc.gz"} |
http://tex.stackexchange.com/questions/84361/different-colours-for-tikz-node-frame-sides/84500 | # Different colours for tikz node frame sides
I have a tabular with and use tikz to create a frame around it. Right now it looks like this:
\documentclass{scrartcl}
\usepackage{tikz}
\begin{document}
\tikz\node[draw=black,ultra thick,double=gray,inner sep=.3pt+\pgflinewidth]{
\begin{tabular}{l|l}
A & B\\
\hline
C & D\\
\end{tabular}};
\end{document}
For some very simple 3d effect I want to seperatly adjust the colour of the frame parts. For example in the top and right part of the frame the outer line in black and the inner line in gray. And in the left and bottom part the outher way round.
EDIT: I did a minimal example in HTML/CSS:
To get the desired effect I need the edges to be in an angle of 45°.
-
looks familiar :) could you turn your snippet into a complete MWE so that others can play with it easily? :) – cmhughes Nov 26 '12 at 20:49
definitely not an answer, but might get you started: \usetikzlibrary{fadings} and then \tikz\node[draw=black,ultra thick,double=gray,inner sep=.3pt+\pgflinewidth] [postaction={path fading=south,fill=white}] {\begin{tabular}{l|l} ... produces some effects- it's not quite what you've described though – cmhughes Nov 26 '12 at 22:43
@cmhughes: yea, its pretty much a follow up question to your answer (tex.stackexchange.com/a/84258/15061). I hope I extened my code to be a MWE. Also I did an html example of what I am looking for. – Haatschii Nov 27 '12 at 14:18
I took the liberty of converting your example image to .png format and uploading it here; I hope it's OK. – Gonzalo Medina Nov 27 '12 at 15:34
@GonzaloMedina Sure, good idea. – Haatschii Nov 28 '12 at 13:27
Here's a possible solution; the \myboxed command surround its contents with a frame having the requested specifications; the syntax is:
\myboxed[<length>][<color1>][<color2>]{<contents>}
<length> controls the width of the frame (default=2pt); using the second and third optional arguments you can change the colors used (defaults=black and gray):
\documentclass{article}
\usepackage{xparse}
\usepackage{tikz}
\newlength\unit
\NewDocumentCommand\myboxed{O{2pt}O{black}O{gray}m}{%
\setlength\unit{#1}
\begin{tikzpicture}
\node[inner sep=0pt] (a) {#4};
\fill[#2] (a.south east) --
([xshift=\unit,yshift=-\unit]a.south east) |-
([xshift=-\unit,yshift=\unit]a.north west) --
(a.north west) -|
(a.south east) --
cycle;
\fill[#3] (a.south east) --
([xshift=\unit,yshift=-\unit]a.south east) -|
([xshift=-\unit,yshift=\unit]a.north west) --
(a.north west) |-
(a.south east) --
cycle;
\fill[#3] ([xshift=\unit,yshift=-\unit]a.south east) --
([xshift=2*\unit,yshift=-2*\unit]a.south east) |-
([xshift=-2*\unit,yshift=2*\unit]a.north west) --
([xshift=-\unit,yshift=\unit]a.north west) -|
([xshift=\unit,yshift=\unit]a.south east) --
cycle;
\fill[#2] ([xshift=\unit,yshift=-\unit]a.south east) --
([xshift=2*\unit,yshift=-2*\unit]a.south east) -|
([xshift=-2*\unit,yshift=2*\unit]a.north west) --
([xshift=-\unit,yshift=\unit]a.north west) |-
([xshift=-\unit,yshift=-\unit]a.south east) --
cycle;
\end{tikzpicture}
}
\begin{document}
\myboxed{\begin{tabular}{l|l}
A & B \\
\hline
C & D \\
\myboxed[4pt]{\begin{tabular}{l|l|l}
A & B & C \\
\hline
C & D & E \\
\hline
F & G & H \\
\myboxed[6pt][black!80][gray!50]{\begin{tabular}{l|l|l}
A & B & C \\
\hline
C & D & E \\
\hline
F & G & H \\
\end{tabular}}
\end{document}
-
Thanks, it is pretty much, what I was looking for, exepct for the edges that should be in an angle of 45°. I added an example in my question. – Haatschii Nov 27 '12 at 14:21
@Haatschii answer updated with the 45 degree angle. – Gonzalo Medina Nov 27 '12 at 15:10
Great, thank you so much. I think I have to spend some time reading the tikz manual to understand what you are doing, though. But for now this is exactly what I wanted. – Haatschii Nov 28 '12 at 13:26
In Tikz it's not that straightforward to get angled linecaps (see TikZ: changing colour of a path half way along )so one needs to draw the extra bit manually either as a full rectangular path or just playing around with the tip (with a new arrow probably. See Luigi's wonders in Is it possible to change the size of an arrowhead in TikZ/PGF? )
Here is the simplest that I can think of
\documentclass[tikz]{standalone}
\newcommand\htmlbutton[4]{
\foreach \x/\z/\y in {|-/-|/#3,-|/|-/#4}{
\fill[fill=\y,line join=bevel] ([shift={(135:#2)}]#1.north west) \x
([shift={(-45:#2)}]#1.south east) -- (#1.south east) \z
(#1.north west)--cycle;
}
}
\begin{document}
\begin{tikzpicture}
\node[outer sep=0,inner sep=1pt] (a) {Test test};
\htmlbutton{a}{2pt}{gray}{gray!40}
\end{tikzpicture}
\end{document}
You can add another layer with the contrast colors to get the 3D effect.
-
Thanks a lot. Your example also works well. It always this problem that I can only accept one answer. :/ – Haatschii Nov 28 '12 at 13:27
@Haatschii No problem at all. – percusse Nov 28 '12 at 13:43 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.789514422416687, "perplexity": 2575.2667357984287}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464049281876.4/warc/CC-MAIN-20160524002121-00243-ip-10-185-217-139.ec2.internal.warc.gz"} |
http://myafricanschool.com/grade12workenergyandpower | Thursday, February 2, 2023
## Grade 12 Work, Energy and Power
#### 1.Introduction
We use the term ‘work’ in everyday conversation to mean many different things. We talk about going to work, doing homework, working in class. Physicists mean something very specific when they talk about work. In Physics we use the term work to describe the process of transferring energy from object or system to another or converting energy from one form to another. You will learn that work and energy are closely related to Newton’s laws of motion. You shall see that the energy of an object is its capacity to do work and doing work is the process of transferring energy from one object or form to another by means of a force. In other words,
• an object with lots of energy can do lots of work.
• when object A transfers energy to object B, the energy of object A decreases by the same amount as the energy of object B increases, we say that object A does work on object B.
Lifting objects or throwing them requires that you do work on them. Even making an electrical current flow requires that something do work. Objects or systems must have energy to be able to do work on other objects or systems by transferring some of their energy.
• Units and unit conversions — Physical Sciences, Grade 10, Science skills
• Equations — Mathematics, Grade 10, Equations and inequalities
• Techniques of vector addition —Physical Sciences, Grade 10, Vectors and scalars
• Newton’s laws — Physical Sciences, Grade 11, Forces
• Force diagrams — Physical Sciences, Grade 11, Forces
#### 2. Work
We cover different topics in different chapters in different grades but that doesn’t mean that they are not related. In fact, it is very important to note that all of the different topics related to mechanics (forces, mechanical energy, momentum, rectilinear motion) actually form a consistent picture of the same physical system. There have been
examples where we’ve shown the same results using two methods, for example determining speed or velocity using equations of motion or conservation of mechanical energy. Learning about work will help us tie everything we’ve learnt about previously together.
Work will allow us to connect energy transfer to forces, which we have already linked to momentum and the equations of motion. When a force tends to act in or against the direction of motion of an object we say that the force is doing work on the object. Specifically, work is defined mathematically in terms of the force and the displacement of the object.
DEFINITION: Work
When a force acts in or against the direction of motion of an object, work is done on
the object.W = FΔx cos θ
Important: cos θ tells you the relative direciton of the force and the displacment which is important. If the component of the force along the direction of the displacement is opposite in direction to the displacement then the sign of the displacement vector and force vector will be different. This is regardless of which direction was chosen as a positive direction.
Let us look at some examples to understand this properly. In the images below the grey dot represents an object. A force, $$\vec{F}$$, acts on the object. The object moves through a displacement, Δ$$\vec{x}$$. What is the sign of the work done in each case?
It is only the direction of the force on the object that matters and not the direction from the source of the force to the object. In Figure 5.3 both powerlifters are exerting an upwards force on the weights. On the left the weight is being pulled upwards and on the right it is being pushed upwards.
Weight lifting is a good context in which to think about work because it helps to identify misconceptions introduced by everyday use of the term ‘work’. In the two cases in Figure 5.3 everyone would describe moving the weights upwards as very hardwork. From a physics perspective, as the powerlifters lift the weight they are exerting
a force in the direction of the displacement so positive work is done on the weights.
Consider the strongman walking in Figure 5.4. He carries two very heavy sleds as far as he can in a competition. What work is the man doing on the sleds and why?
Most people would say he is working very hard because the sleds are heavy to carry but from a physics perspective he is doing no work on the sleds. The reason that he does no work is because the force he exerts is directly upwards to balance the force of gravity and the displacement is in the horizontal direction.
Therefore there is no component of the force in the direction of displacement (θ = 90°) and no work done. His muscles do need to use their energy reserves to maintain the force to balance gravity. That does not result in energy transfer to the sleds.
Investigation: Is work done?
Decide whether or not work is done in the following situations. Remember that for work to be done a force must be applied in the direction of motion and there must be a displacement. Identify which two objects are interacting, what the action-reaction pairs of forces are and why the force described is or isn’t doing work.
1. Max pushes against a wall and becomes tired.
2. A book falls off a table and free falls to the ground.
3. A rocket accelerates through space.
4. A waiter holds a tray full of plates above his head with one arm and carries it straight across the room at constant speed.
For each of the above pictures, the force vector is acting in the same direction as the displacement vector. As a result, the angle θ = 0°because there is no difference in angle between the direction of applied force and the direction of displacement.
The work done by a force can then be positive or negative. This sign tells us about the direction of the energy transfer. Work is a scalar so the sign should not be misinterpreted to mean that work is a vector. Work is defined as energy transfer, energy is a scalar quantity and the sign indicates whether energy was increased or decreased.
• If $$\vec{F}$$applied acts or has a component acting in the same direction as the motion, then positive work is being done. In this case the object on which the force is applied gains energy.
• If the direction of motion and $$\vec{F}$$applied are opposite, then negative work is being done. This means that energy is lost and the object exerting the force gains energy. For example, if you try to push a car uphill by applying a force up the slope and instead the car rolls down the hill you are doing negative work on the car. Alternatively, the car is doing positive work on you! applied
Worked example 1: Calculating work on a car when speeding up.
QUESTION
A car is travelling along a straight horizontal road. A force of 500 N is applied to the car in the direction that it is travelling, speeding it up. While it is speeding up is covers a distance of 20 m. Calculate the work done on the car.
SOLUTION
Step 1: Analyse the question to determine what information is provided
• The magnitude of the force applied is F = 500 N.
• The distance moved is Δx = 20 m.
• The applied force and distance moved are in the same direction. Therefore, the angle between the force and displacement is θ = 0°
These quantities are all in SI units, so no unit conversions are required.
Step 2: Analyse the question to determine what is being asked
• We are asked to find the work done on the car. We know from the definition that work done is W = FΔx cosθ.
Step 3: Next we substitute the values and calculate the work done
W = FΔx cosθ.
=(500) (20) (cos 0)
=(500) (20) (1)
= 10 000 J
Remember that the answer must be positive, as the applied force and the displacement are in the same direction.
In this case, the car gains kinetic energy.
Worked example 2: Calculating work on the car while braking
What happens when the applied force and the motion are not parallel? By using the formula W = FΔx cosθ , we are actually calculating the component of the applied force in the direction of motion. Note that the component of the force perpendicular to the direction of motion does no work.
Worked example 3: Calculating work done on a box pulled at an angle
QUESTION
Calculate the work done on a box, if it is pulled 5 m along the ground by applying a force of F = 20 N at an angle of 60° to the horizontal.
SOLUTION
Step 1: Analyse the question to determine what information is provided
• The force applied is F=20 N
• The distance moved is Δx = 5 m along the ground
• The angle between the applied force and the motion is θ=60
These quantities are in the correct units so we do not need to perform any unit conversions.
Step 2: Analyse the question to determine what is being asked
We are asked to find the work done on the box.
Step 3: Substitute and calculate the work done
Now we can calculate the work done on the box:
W = FΔx cos θ
=(20) (5) (cos 60)
= 50 J
Note that the answer is positive as the component of the force parallel to the direction of motion is in the same direction as the motion. The work done on the box is 50J.
Exercise 5 – 1: Work
1.A 10 N force is applied to push a block across a frictionless surface for a displacement of 5,0 m to the right. The block has a weight of 20 N. Determine the work done by the following forces: normal force, weight , applied force.
2. A 10 N frictional force slows a moving block to a stop after a displacement of 5,0 m to the right. The block has a weight of 20 N Determine the work done by the following forces: normal
force, weight, frictional force.
3. A 10 N force is applied to push a block across a frictional surface at constant speed for a displacement of 5,0 m to the right. The block has a weight of 20 N and the frictional force is 10 N. Determine the work done by the following forces: normal force, weight, applied force and frictional force.
4.An object with a weight of 20 N is sliding at constant speed across a frictionless surface for a displacement of 5 m
to the right. Determine if there is any work done.
5.An object with a weight of 20 N is pulled upward at constant speed by a 20 N force for a vertical displacement of 5m . Determine if there is any work done.
6. Before beginning its descent, a roller coaster is always pulled up the first hill to high initial height. Work is done on the roller coaster to achieve this initial height. A coaster designer is considering three different incline angles of the hill at which to drag the 2000 kg car train to the top of the 60 m high hill. In each case, the force applied to the car will be applied parallel to the hill. Her critical question is: which angle would require the least work? Analyse the data, determine the work done in each case, and answer this critical question.
7. A traveller carries a 150 N suitcase up four flights of stairs (a total height of 12 m) and then pushes it with a horizontal force of 60 N at a constant speed of 0,25 m.s-1 for a horizontal distance of 50 m on a frictionless surface. How much work does the traveller do on the suitcase during this entire trip?
8. A parent pushes down on a pram with a force of 50 N at an angle of 30 to the horizontal. The pram is moving on a frictionless surface. If the parent pushes the pram for a horizontal distance of 30 m, how work is done on the pram?
9. How much work is done by the force required to raise a 2000 N lift 5 floors vertically at a constant speed? The vertical distance between floors is 5 m high.
10. A student with a mass of 60 kg runs up three flights of stairs in 15 s, covering a vertical distance of 10 m. Determine the amount of work done by the student to elevate her body to this height.
Net work
We have only looked at a single force acting on an object. Sometimes more than one force acts at the same time (we dealt with this in Grade 11). We call the work done after taking all the forces into account the net work done. If there is only one force acting then the work it does, if any, is the net work done. In this case there are two equivalent approaches we can adopt to finding the net work done on the object. We can:
• Approach 1: calculate the work done by each force individually and then sum them taking the signs into account. If one force does positive work and another does the same amount of work but it is negative then they cancel out.
• Approach 2: calculate the resultant force from all the forces acting and calculate the work done using the resultant force. This will be equivalent to Approach 1.
If the resultant force parallel to the direction of motion is zero, no net work will be done.
Remember that work done tells you about the energy transfer to or from an object by means of a force. That is why we can have zero net work done even if multiple large forces are acting on an object. Forces that result in positive work increase the energy of the object, forces that result in negative work reduce the energy of an object. If as
much energy is transferred to an object as is transferred away then the final result is that the object gains no energy overall.
Worked example 4: Approach 1, calculating the net work on a car
QUESTION
The same car is now accelerating forward, but friction is working against the motion of the car. A force of 300 N is applied forward on the car while it is travelling 20 m forward. A frictional force of 100 N acts to oppose the motion. Calculate the net work done on the car.
Only forces with a component in the plane of motion are shown on the diagram. No work is done by Fg or FNormal as they act perpendicular to the direction of motion.
SOLUTION
Step 1: Analyse the question to determine what information is provided
• The force applied is Fapplied=300 N forwards.
• The force of friction is Ffriction=100 N opposite to the direction of motion.
• The distance moved is Δx = 20 m.
The applied force and distance moved are in the same plane so we can calculate friction the work done by the applied forward force and the work done by the force of friction backwards.
Step 2: Analyse the question to determine what is being asked
We are asked to find the net work done on the car. We know from the definition that work done is W = FΔx cosθ
As mentioned before, there is an alternative method to solving the same problem, which is to determine the net force acting on the car and to use this to calculate the work. This means that the vector forces acting in the plane of motion must be added to get the net force $$\vec{F}$$net. The net force is then applied over the displacement to get the net work Wnet.
Worked example 5: Approach 2, calculating the net force
QUESTION
The same car is now accelerating forward, but friction is working against the motion of the car. A force of 300 N is applied forward on the car while it is travelling 20m forward. A frictional force of 100 N acts to oppose the motion. Calculate the net work
done on the car.
SOLUTION
Step 1: Analyse the question to determine what information is provided
• The force applied is $$\vec{F}$$applied=300 N forwards.
• The force of friction is $$\vec{F}$$friction=100 N backwards.
• The distance moved is Δx = 20 m.
• The applied forces $$\vec{F}$$applied = 300 N and the force of friction $$\vec{F}$$friction= 100 N are in the same plane as the distance moved. Therefore, we can add the vectors. As vectors require direction, we will say that forward is positive and therefore backward is negative. Note, the force of friction is acting at 180° friction i.e. backwards and so is acting in the opposite vector direction i.e. negative.
These quantities are all in the correct units, so no unit conversions are required.
Step 2: Analyse the question to determine what is being asked
• We are asked to find the net work done on the car. We know from the definition that work done is Wnet=FnetΔxcosθ
Step 3: We calculate the net force acting on the car, and we convert this into net work.
First we draw the force diagram:
Let forwards (to the left in the picture) be positive. We know that the motion of the car is in the horizontal direction so we can neglect the force due to gravity, $$\vec{F}$$g , and the normal force, $$\vec{N}$$. Note: if the car were on a slope we would need to calculate the component of gravity parallel to the slope.
$$\vec{F}$$net=$$\vec{F}$$applied+$$\vec{F}$$friction
=(+300)+(-100)
$$\vec{F}$$ = 200 N forwards
$$\vec{F}$$net is pointing in the same direction as the displacement, therefore the angle between the force and displacement is θ = 0.
IMPORTANT!
The two different approaches give the same result but it is very important to treat the signs correctly. The forces are vectors but work is a scalar so they shouldn’t be interpreted in the same way.
Wnet= FnetΔxcosθ
=(200) (20)cos(0)
= 4000 J
#### 3. Work Theorem
Conservative and non-conservative forces
In Grade 10, you saw that mechanical energy was conserved in the absence of non-conservative forces. It is important to know whether a force is an conservative force or an non-conservative force in the system, because this is related to whether the force can change an object’s total mechanical energy when it does work on an object.
When the only forces doing work are conservative forces (for example, gravitational and spring forces), energy changes forms – from kinetic to potential (or vice versa); yet the total amount of mechanical energy (EK+ Ep) is conserved. For example, as an object falls in a gravitational field from a high elevation to a lower elevation, some of the object’s potential energy is changed into kinetic energy. However, the sum of the kinetic and potential energies remain constant.
Investigation: Non-conservative forces
We can investigate the effect of non-conservative forces on an object’s total mechanical energy by rolling a ball along the floor from point A to point B.
In the absence of friction and other non-conservative forces, the ball should slide along the floor and its speed should be the same at positions A and B. Since there are no non-conservative forces acting on the ball, its total mechanical energy at points A and B are equal.
Now, let’s investigate what happens when there is friction (an non-conservative force) acting on the ball.
Roll the ball along a rough surface or a carpeted floor. What happens to the speed of the ball at point A compared to point B?
If the surface you are rolling the ball along is very rough and provides a large non-conservative frictional force, then the ball should be moving much slower at point B than at point A.
Let’s compare the total mechanical energy of the ball at points A and B:
However, in this case, VA ≠ VB and therefore ETotal,A ≠ ETotal,B. Since
VA>VB
ETotal,A> ETotal,B
Therefore, the ball has lost mechanical energy as it moves across the carpet. However,although the ball has lost mechanical energy, energy in the larger system has still been conserved. In this case, the missing energy is the work done by the carpet through applying a frictional force on the ball. In this case the carpet is doing negative work on
the ball.
When an non-conservative force (for example friction, air resistance, applied force) does work on an object, the total mechanical energy (EK+ Ep) of that object changes. If positive work is done, then the object will gain energy. If negative work is done, then the object will lose energy.
When a net force does work on an object, then there is always a change in the kinetic energy of the object. This is because the object experiences an acceleration and therefore a change in velocity. This leads us to the work-energy theorem.
DEFINITION: Work-energy theorem
The work-energy theorem states that the work done on an object by the net force is equal to the change in its kinetic energy:
WNet=ΔEk=Ek,f-Ek,i
Worked example 6: Work-energy theorem
QUESTION
A 1 kg brick is dropped from a height of 10 m. Calculate the work that has been done on the brick between the moment it is released and the moment when it hits the ground. Assume that air resistance can be neglected.
SOLUTION
Step 1: Determine what is given and what is required
• Mass of the brick: m = 1 kg.
• Initial height of the brick: hi= 10 m.
• Final height of the brick: hfi= 0 m.
• We are required to determine the work done on the brick as it hits the ground.
Step 2: Determine how to approach the problem
The brick is falling freely, so energy is conserved. We know that the work done is equal
to the difference in kinetic energy. The brick has no kinetic energy at the moment it
is dropped, because it is stationary. When the brick hits the ground, all the brick’s
potential energy is converted to kinetic energy.
Step 3: Determine the brick’s potential energy at hi
Ep= m.g.hi
=(1) (9,8) (10)
= 98 J
Step 4: Determine the work done on the brick
The brick had 98 J of potential energy when it was released and 0 J of kinetic energy. When the brick hit the ground, it had 0 J of potential energy and 98 J of kinetic energy.
Therefore Ek,i= 0 J and Ek,f= 98 J.
From the work-energy theorem:
Wnet = ΔEk
= Ek,fEk,i
= 98 – 0
= 98 J
Hence, 98 J of work was done on the brick.
Worked example 7: Work-energy theorem 2
QUESTION
The driver of a 1000 kg car travelling at a speed of 16,7 m.s-1 applies the car’s brakes when he sees a red light. The car’s brakes provide a frictional force of 8000 N. Determine the stopping distance of the car.
SOLUTION
Step 1: Determine what is given and what is required
We are given:
• mass of the car: m = 1000 kg
• speed of the car: v = 16,7 m.s-1
• frictional force of brakes: $$\tilde{F}$$= 8000 N
We are required to determine the stopping distance of the car.
Step 2: Determine how to approach the problem
We apply the work-energy theorem. We know that all the car’s kinetic energy is lost to friction. Therefore, the change in the car’s kinetic energy is equal to the work done by the frictional force of the car’s brakes.Therefore, we first need to determine the car’s kinetic energy at the moment of braking using: Ek=½mv2
This energy is equal to the work done by the brakes. We have the force applied by the brakes, and we can use: W = FΔx cosθ to determine the stopping distance.
Worked example 8: Block on an inclined plane [credit: OpenStax College]
QUESTION
A block of 2 kg is pulled up along a smooth incline of length 10 m and height 5 m by applying an non-conservative force. At the end of incline, the block is released from rest to slide down to the bottom. Find the
1. work done by the non-conservative force,
2. the kinetic energy of the block at the end of round trip, and
3. the speed at the end of the round trip.
We have represented the non-conservative force on the force diagram with an arbitrary vector$$\tilde{F}$$ acts only during upward journey. Note that the block is simply released at the end of the upward journey. We need to find the work done by the non-conservative force only during the upward journey.
WF=WF(up)+WF(down)=WF(up)+0=WF(up)
The kinetic energies in the beginning and at the end of the motion up the slope are zero.
We can conclude that sum of the work done by all three forces is equal to zero during the upward motion. The change in kinetic energy is zero which implies that the net work done is zero.
WNet = WF(up)+Wg(up)+WN(up)
0 = WF(up)+Wg(up)+WN(up)
If we know the work done by the other two forces (normal force and gravity), then we can calculate the work done by the non-conservative force, F, as required.
Step 3: Work done by normal force during upward motion
The block moves up the slope, the normal force is perpendicular to the slope and,
therefore, perpendicular to the direction of motion. Forces that are perpendicular to the direction of motion do no work.
WNet = WF(up)+Wg(up)+WN(up)
0 = WF(up)+Wg(up)+WN(up)
WF(up) = -Wg(up)
IMPORTANT!
Be careful not to be confused by which angle has been labelled α and which θ. α is not the angle between the force and the direction of motion but the incline of the plane in this particular problem. It is important to understand which symbol represents which physical quantity in the equations you have learnt.
Hence, the work done by the non-conservative force during the round trip is
WF(up) = WF(up)= – Wg(up)
= – (-98)
= 98 J
Step 5: Kinetic energy at the end of round trip
The kinetic energy at the end of the upward motion was zero but it is not zero at the end of the entire downward motion.
We can use the work-energy theorem to analyse the whole motion:
W(round trip) = Ek,f– Ek,i
= Ek,f– 0
= Ek,f
Exercise 5 – 2: Energy
1. Fill in the table with the missing information using the positions of the 1 kg ball in the diagram below combined with the work-energy theorem.
2. A falling ball hits the ground at 10 m.s-1 in a vacuum. Would the speed of the ball be increased or decreased if air resistance were taken into account. Discuss using the work-energy theorem.
3. A pendulum with mass 300 g is attached to the ceiling. It is pulled up to point A which is a height h = 30 cm from the equilibrium position.
Calculate the speed of the pendulum when it reaches point B (the equilibrium point). Assume that there are no non-conservative forces acting on the pendulum.
#### 4. Conservation of energy
There are two categories of forces we will consider, conservative and non-conservative.
DEFINITION: Conservative force
A conservative force is one for which work done by or against it depends only on the starting and ending points of a motion and not on the path taken.
A conservative force results in stored or potential energy and we can define a potential energy (Ep ) for any conservative force.
Gravity is a conservative force and we studied gravitational potential energy in Grade
10. We now have all the concepts we need to actually deduce this ourselves. Let us consider pushing a ball up a number of different slopes.
Figure 5.5: Three different slopes are shown, all rising to a height of h . The imaginary right- angled triangle is shown for each slope. d is the length of the slope. α is the angle the slope makes with the horizontal.
The slope, of length d is the hypotenuse of an imaginary right-angled triangle. The work done by gravity while pushing a ball of mass, m , up each of the slopes can be
This final result is independent of the angle of the slope. This is because sinα opposite/hypotenuse=h/d and so the distance cancels out. If the ball moves down the slope the only change is the sign, the work done by gravity still only depends on the change in height. This is why mechanical energy includes gravitational potential energy and is conserved. If an object goes up a distance h gravity does negative work, if it moves back down h gravity does positive work, but the absolute amount of work is the same so you ‘get it back’, no matter what path you take!
This means that the work done by gravity will be same for the ball moving up any
of the slopes because the end position is at the same height. The different slopes do
not end in exactly the same position in the picture. If we break each slope into two
sections as show in Figure 5.6 then we have 3 different paths to precisely the same
end-point. In this case the total work done by gravity along each path is the sum of the
work done on each piece which is just related to the height. The total work done is
related to the total height.
Figure 5.6: Three different paths that lead from the same start-point to the same-end point. Each path leads to the same overall change in height, h, and, therefore, the same work done by gravity.
There are other examples, when you wind up a toy, an egg timer, or an old-fashioned watch, you do work against its spring and store energy in it. (We treat these springs as ideal, in that we assume there is no friction and no production of thermal energy.) This stored energy is recoverable as work, and it is useful to think of it as potential energy contained in the spring. The total work done by a conservative force results in a change in potential energy, ΔEp. If the conservative force does positive work then the change in potential energy is negative. Therefore:
DEFINITION: Non-conservative force
A non-conservative force is one for which work done on the object depends on the path taken by the object.
IMPORTANT!
Non-conservative forces do not imply that total energy is not conserved. Total energy is always conserved. Non-conservative forces mean that mechanical energy isn’t conserved in a particular system which implies that the energy has been transferred in a process that isn’t reversible.
Friction is a good example of a non-conservative force because if removes energy from the system so the amount of mechanical energy is not conserved. Non-conservative forces can also do positive work thereby increasing the total mechanical energy of the system.
The energy transferred to overcome friction depends on the distance covered and is converted to thermal energy which can’t be recovered by the system.
Non-conservative forces and work-energy theorem
We know that the net work done will be the sum of the work done by all of the individual forces:
When the non-conservative forces oppose the motion, the work done by the non-conservative forces is negative, causing a decrease in the mechanical energy of the system. When the non-conservative forces do positive work, energy is added to the system. If the sum of the non-conservative forces is zero then mechanical energy is conserved.
Worked example 9: Sliding footballer [credit: OpenStax College Physics]
QUESTION
Consider the situation shown where a
football player slides to a stop on level ground. Using energy considerations,
calculate the distance the 65,0 kg football
player slides, given that his initial
speed is 6,00 m.s-1 and the force
of friction against him is a constant
450 N.
SOLUTION
Step 1: Analyse the problem and determine what is given
Friction stops the player by converting his kinetic energy into other forms, including thermal energy. In terms of the work-energy theorem, the work done by friction, which is negative, is added to the initial kinetic energy to reduce it to zero. The work done by friction is negative, because F is in the opposite direction of the motion (that is,θ = 180 of, and so cos θ = 1). Thus Wnon-conservative = –FfΔx
There is no change in potential energy.
Step 3: Quote the final answer
The footballer comes to a stop after sliding for 2,60 m.
Discussion
The most important point of this example is that the amount of non conservative work equals the change in mechanical energy. For example, you must work harder to stop a truck, with its large mechanical energy, than to stop a mosquito.
Worked example 10: Sliding up a slope [credit: OpenStax College Physics]
QUESTION
The same 65,0 kg footballer running at the same speed of 6,00 m.s-1 dives up the
inclined embankment at the side of the field. The force of friction is still 450 N as it is
the same surface, but the surface is inclined at 5o . How far does he slide now?
SOLUTION
Step 1: Analyse the question
Friction stops the player by converting his kinetic energy into other forms, including
thermal energy, just in the previous worked example. The difference in this case is that
the height of the player will change which means a non-zero change to gravitational
potential energy.
The work done by friction is negative, because Ff is in the opposite direction of the motion (that is, θ = 180).
We sketch the situation showing that the footballer slides a distance d up the slope.
As might have been expected, the footballer slides a shorter distance by sliding uphill.Note that the problem could also have been solved in terms of the forces directly and the work energy theorem, instead of using the potential energy. This method would have required combining the normal force and force of gravity vectors, which no longer cancel each other because they point in different directions, and friction, to find the net force. You could then use the net force and the net work to find the distance d that reduces the kinetic energy to zero. By applying conservation of energy and using the potential energy instead, we need only consider the gravitational potential energy, without combining and resolving force vectors. This simplifies the solution considerably.
Exercise 5 – 3: Energy conservation
1. A 60,0 kg skier with an initial speed of 12,0 m.s-1
coasts up a 2,50 m-high rise as shown in the figure. Find her final speed at the top, given that the coefficient of friction between her skis and the snow is 0,0800. (Hint: Find the distance traveled up the incline assuming a straight-line path as shown in the figure.)
2. a) How high a hill can a car coast up (engine disengaged) if work done by friction is negligible and its initial speed is 110 km.h-1 ?
b) If, in actuality, a 750 kg car with an initial speed of 110 km.h-1 is observed to coast up a hill to a height 22,0 m above its starting point, how much thermal energy was generated by friction?
c) What is the average force of friction if the hill has a slope 2,5 above the horizontal?
3. A bullet traveling at 100 m/s just pierces a wooden plank of 5 m. What should be the speed (in m/s) of the bullet to pierce a wooden plank of same material, but having a thickness of 10m?
#### 5. Power
Now that we understand the relationship between work and energy, we are ready to look at a quantity related the rate of energy transfer. For example, a mother pushing a trolley full of groceries can take 30 s or 60 s to push the trolley down an aisle. She does the same amount of work, but takes a different length of time. We use the idea of power to describe the rate at which work is done
Power is defined as the rate at which work is done or the rate at which energy is transfered to or from a system. The mathematical definition for power is: P = W/t
IMPORTANT!
In the case where the force and the velocity are in opposite directions the power will be negative.
The unit of power is watt (symbol W).
Worked example 11: Power calculation 1
QUESTION
Calculate the power required for a force of 10 N applied to move a 10 kg box at a speed of 1 m·s−1 over a frictionless surface.
SOLUTION
Step 1: Determine what is given and what is required.
• We are given the force, F = 10 N.
• We are given the speed, v = 1 m · s−1 .
• We are required to calculate the power required
Step 2: Draw a force diagram
Step 3: Determine how to approach the problem from the force diagram, we see that the weight of the box is acting at right angles to the direction of motion. The weight does not contribute to the work done and does not contribute to the power calculation. We can therefore calculate power from: P = F · v .
Step 4: Calculate the power required
P = F · v
= (10 N) 1 m · s−1
= 10 W
Step 5: Write the final answer
10 W of power are required for a force of 10 N to move a 10 kg box at a speed of 1 m·s−1
Machines are designed and built to do work on objects. All machines usually have a power rating. The power rating indicates the rate at which that machine can do work upon other objects.
A car engine is an example of a machine which is given a power rating. The power rating relates to how rapidly the car can accelerate. Suppose that a 50 kW engine could accelerate the car from 0 km·hr−1 to 60 km·hr−1 in 16 s. Then a car with four times the power rating (i.e. 200 kW) could do the same amount of work in a quarter of the time. That is, a 200 kW engine could accelerate the same car from 0 km·hr−1 to 60 km·hr−1 in 4s.
Worked example 12: Power calculation 2
QUESTION
A forklift lifts a crate of mass 100 kg at a constant velocity to a height of 8 m over a time of 4 s. The forklift then holds the crate in place for 20 s. Calculate how much power the forklift exerts in lifting the crate? How much power does the forklift exert in holding the crate in place?
SOLUTION
Step 1: Determine what is given and what is required
We are given:
• mass of crate: m=100 kg
• height that crate is raised: h=8 m
• time taken to raise crate: tr = 4 s
• time that crate is held in place: ts = 20 sWe are required to calculate the power exerted.
Step 2: Determine how to approach the problem
We can use:
to calculate power. The force required to raise the crate is equal to the weight of the crate.
Step 3: Calculate the power required to raise the crate
Step 4: Calculate the power required to hold the crate in place
While the crate is being held in place, there is no displacement. This means there is no work done on the crate and therefore there is no power exerted.
Step 5: Write the final answer
1960 W of power is exerted to raise the crate and no power is exerted to hold the crate in place.
Worked example 13: Stair climb
QUESTION
Step 3: Quote the final answer
The power generated is 538,0 W.
The woman does 1764 J of work to move up the stairs compared with only 120 J to increase her kinetic energy; thus, most of her power output is required for climbing rather than accelerating.
Worked example 14: A borehole
QUESTION
What is the power required to pump water from a borehole that has a depth h =
15,0 m at a rate of 20,0 l·s−1 ?
SOLUTION
Step 1: Analyse the question
We know that we will have to do work on the water to overcome gravity to raise it a certain height. If we ignore any inefficiencies we can calculate the work, and power, required to raise the mass of water the appropriate height.
We know how much water is required in a single second. We can first determine the mass of water: 20,0 l × 1 kg/1l = 20,0 kg.
The water will also have non-zero kinetic energy when it gets to the surface because it needs to be flowing. The pump needs to move 20,0 kg from the depth of the borehole
every second, we know the depth so we know the speed that the water needs to be moving is v = h/t = 15,0/1 = 15,0 m·s−1 .
Experiment: Simple measurements of human power
You can perform various physical activities, for example lifting measured weights or climbing a flight of stairs to estimate your output power, using a stop watch. Note: the human body is not very efficient in these activities, so your actual power will be much greater than estimated here.
Exercise 5 – 4: Power
1. [IEB 2005/11 HG] Which of the following is equivalent to the SI unit of power:
a) V·A
b) V·A−1
c) kg·m·s−1
d) kg·m·s−2
2. Two students, Bill and Bob, are in the weight lifting room of their local gym. Bill lifts the 50 kg barbell over his head 10 times in one minute while Bob lifts the
50 kg barbell over his head 10 times in 10 seconds. Who does the most work? Who delivers the most power? Explain your answers.
3. Jack and Jill ran up the hill. Jack is twice as massive as Jill; yet Jill ascended the same distance in half the time. Who did the most work? Who delivered the most power? Explain your answers.
4. When doing a chin-up, a physics student lifts her 40 kg body a distance of 0,25 m in 2 s. What is the power delivered by the student’s biceps?
5. The unit of power that is used on a monthly electricity account is kilowatt-hours (symbol kWh). This is a unit of energy delivered by the flow of 1 kW of electricity for 1 hour. Show how many joules of energy you get when you buy 1 kWh of electricity.
6. An escalator is used to move 20 passengers every minute from the first floor of a shopping mall to the second. The second floor is located 5-meters above the first floor. The average passenger’s mass is 70 kg. Determine the power requirement of the escalator in order to move this number of passengers in this amount of time.
#### 6. Chapter Summary
Exercise 5 – 5:
1. How much work does a person do in pushing a shopping trolley with a force of
200 N over a distance of 80 m in the direction of the force?
2. How much work does the force of gravity do in pulling a 20 kg box down a 45◦
frictionless inclined plane of length 18 m?
3. [IEB 2001/11 HG1] Of which one of the following quantities is kg·m2 ·s−3 the base S.I. unit?
4. [IEB 2003/11 HG1] A motor is used to raise a mass m through a vertical height h in time t. What is the power of the motor while doing this?
5. [IEB 2002/11 HG1] An electric motor lifts a load of mass M vertically through a height h at a constant speed v. Which of the following expressions can be used to calculate the power transferred by the motor to the load while it is lifted at constant speed?
6. A set 193 kg containers need to be lifted onto higher floors during a building operation. The distance that they need to be raised is 7.5 m, at constant speed. The project manager has determined that in order to keep to budget and time this has to happen in as close to 5,0 s as possible. The power ratings for three motors are listed as 1,0 kW, 3,5 kW, and 5,5 kW. Which motor is best for the job? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8766846656799316, "perplexity": 597.6716979177979}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500041.18/warc/CC-MAIN-20230202200542-20230202230542-00318.warc.gz"} |
https://math.stackexchange.com/questions/2373253/how-is-moving-the-last-digit-of-a-number-to-the-front-and-multiplying-related-to | # How is moving the last digit of a number to the front and multiplying related to multiplicative orders?
There seems to be a relationship between multiplicative orders modulo $n$ and a puzzle Presh Talwalkar gave a few days ago at https://www.youtube.com/watch?v=1lHDCAIsyb8
I'm hoping someone can give a more rigorous explanation of the pattern I see.
$\bullet\textbf{ The Puzzle }\bullet$
He states the puzzle as: "What Positive Number Doubles When Its Last Digit Becomes Its First Digit?"
For example, the smallest solution - assuming base-10 representation - is $105263157894736842$. Which means that $$(2)\cdot105263157894736842 \quad\ \ \$$ $$||$$ $$210526315789473684$$
Naturally, one can proceede to find solutions in other bases. The base-5 solution is $$(2)\cdot102342_5 \quad\ \ \$$ $$||$$ $$210234_5$$
$\bullet\textbf{ Multiplicative Order Connection }\bullet$
The base-10 solutions is $18$ digits and the base-5 solution is $6$ digits. I wrote a program to generate the smallest solution in all bases and then counted the number of digits in each such solution. Here's the sequence, starting with base-2 $$2,4,3,6,10,12,4,8,18,6,11,20,...$$ $$\uparrow \quad\quad\quad\quad\ \uparrow \quad\quad$$ $$\text{Base-} 5 \quad\quad\quad \text{Base-} 10 \quad\quad$$ A quick search on http://oeis.org/ shows that these numbers are the multiplicative order of $$2\ (\text{mod } 2B-1)$$ where $B$ is the representation base we are working in. See http://oeis.org/A002326
This puzzle can be further generalized by finding numbers that triple instead of double upon moving the last digit to the front. Let's introduce an arbitrary multiplying factor: $k$
So the solutions mentioned above and Talwalkar's puzzle are a particular case when $k=2$
For a different example, let's look at $k=5$ in base-7. The smallest solution is $$(5) \cdot 1013042156536245_7 \quad\ \ \$$ $$||$$ $$5101304215653624_7$$
This solution is $16$ digits long. As we did before for base-10, we can write out a sequence of the number of digits in each base's solution starting with base-2 $$6,6,9,2,14,16,4,5,42,18,...$$ $$\uparrow\ \$$ $$\text{Base-}7\ \$$ Another search on http://oeis.org/ quickly shows that these numbers are the multiplicative order of $$5\ (\text{mod } 5\cdot7-1)\quad\text{or rather}\quad 5 \ (\text{mod }34)$$
$\bullet\textbf{ A Conjecture }\bullet$
The pattern might be clear now. After checking other cases, it seems that the smallest positive number in any base $B$ - which is $k$ times the value gotten by moving it's last digit to the front - has a number of digits equal to the multiplicative order of $$k\ (\text{mod } Bk-1)$$ I can see how multiplicative order would be related to this problem. But I can't find an exact reason why this relationship should be so. Is there an intuitive reason?
Given some solution in base $B$ - let's start by assigning the variable $x$ to the digit that get's moved to the front and assigning to the variable $y$ to the rest of the number (Talwalkar did this in his video). So if we have a multiplying factor of $k$ we are looking for a solution to $$k(By+x)=B^nx+y$$ $$\text{where}\quad 0<x<B \quad\text{and}\quad n > \text{log}_B(y) \quad\text{and}\quad B\geq2 \quad\text{and}\quad 2\leq k < B$$ rearranging we get $$y = \frac{x(B^n-k)}{Bk-1}$$ Since $y$ is an integer we conclude that either $x$ or $B^n-k$ is divisible by $Bk-1$. But $x$ can't be divisible by $Bk-1$ because we have $$x<B<2B-1\leq Bk-1\quad\Rightarrow\quad x<Bk-1$$ Therefore $B^n-k$ must be divisible by $Bk-1$. Accordingly we write $$B^n-k\equiv 0\ (\text{mod }Bk-1)$$ $$\Updownarrow$$ $$\quad\quad\quad\quad\quad\quad k\equiv B^n\ (\text{mod }Bk-1) \quad\quad\quad\quad\quad(1)$$ We are almost there. Next we need to note a simple property of our modular arithmetic, namely that $Bk$ has a remainder of $1$ when divided by $Bk-1$ (duh). So we say that $$Bk\equiv 1\ (\text{mod }Bk-1)$$ $$\Downarrow$$ $$\quad\quad\quad\quad\quad\quad (Bk)^n\equiv 1\ (\text{mod }Bk-1) \quad\quad\quad\quad\quad(2)$$ Now we multiply the left and right sides of equations $(1)$ and $(2)$ respectively and observe $$k\cdot(Bk)^n\equiv B^n\cdot1\ (\text{mod }Bk-1)$$ $$\Downarrow$$ $$k^{n+1}B^n\equiv B^n\ (\text{mod }Bk-1)$$ $$\Downarrow$$ $$k^{n+1}\equiv 1\ (\text{mod }Bk-1)$$ Which means that $n+1$ is the multiplicative order of $k\ (\text{mod }Bk-1)$. But before we conclude that the solution also has $n+1$ digits, more needs to be said.
The smallest solution has $1$ as it's first digit. Since $x$ is the first digit of the solution times $k$, we can conclude that $x=k$. Now to put it all together, our solution is $$By+x=\frac{1}{k}(B^nx+y)=\frac{1}{k}(B^nk+y)=B^n+\frac{y}{k}$$ which has $n+1$ digits.
$\bullet\textbf{ Conclusion }\bullet$
We saw that the multiplicative order of $k\ (\text{mod }Bk-1)$ is the number of digits in the smallest solution to Talwalkar's puzzle for the base $B$ and multiplying factor $k$.
It should be noted that we can also conclude that $k$ and $B$ have the same multiplicative order here. As follows $$k\cdot1\equiv B^n\cdot(Bk)\ (\text{mod }Bk-1)$$ $$\Downarrow$$ $$k\equiv B^{n+1}k\ (\text{mod }Bk-1)$$ $$\Downarrow$$ $$1\equiv B^{n+1}\ (\text{mod }Bk-1)$$
The smallest solution has the same number of digits as the multiplicative order of $B\ (\text{mod }Bk-1)$ and of $k\ (\text{mod }Bk-1)$
• "Either $x$ or $B^n-k$ is divisible by $Bk-1$" is only obvious if $Bk-1$ is prime. May 3, 2020 at 13:15 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8699411153793335, "perplexity": 102.51905426017143}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882573145.32/warc/CC-MAIN-20220818003501-20220818033501-00789.warc.gz"} |
https://forum.inductiveautomation.com/t/ignition-maven-plugin-bug-licensefile-in-non-standard-path/12165 | # Ignition Maven Plugin bug - licenseFile in non standard path
The licenseFile parameter is not working for non-standard file paths. From the Exception it looks like the file name is missing from the target path. (Plugin version 1.0.12).
In addition, the use of documentationFile parameter is a bit vague. Docs say [quote]the path to the directory where your documentation can be found[/quote] but it looks like the plugin always copies the /doc folder, and this parameter is only used in the generated xml file, so it should point to a .html file inside the doc folder.
Caused by: java.nio.file.FileAlreadyExistsException: C:\Users\chi\AppData\Local\Temp\modl6420215655759456812 at sun.nio.fs.WindowsFileCopy.copy(WindowsFileCopy.java:124) at sun.nio.fs.WindowsFileSystemProvider.copy(WindowsFileSystemProvider.java:278) at java.nio.file.Files.copy(Files.java:1274) at com.inductiveautomation.ignitionsdk.IgnitionModlMojo.findLicense(IgnitionModlMojo.java:488)
It looks like we need to fix the statement in the docs. The module plugin looks for documentation to be in a ./docs folder by default, as you found (which has been true for past module tools as well). The ‘documentationFile’ tag should be the name or path to your ‘index.html’ (or whatever you’ve named your index) file inside the docs folder.
I’ll update the doc for clarity. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3350861668586731, "perplexity": 4707.959900726002}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780055775.1/warc/CC-MAIN-20210917181500-20210917211500-00138.warc.gz"} |
https://www.cranewarningsystemsatlanta.com/post/how-does-wind-affect-tower-cranes | Search
# How Does Wind Affect Tower Cranes?
We often take the raw power of wind for granted, considering it a mere nuisance blowing leaves and litter around like some weakling—except, of course, when there is a severe storm that we have to deal with.
However, with tower cranes, the case is entirely different, where even the seemingly humble air currents can cause significant disaster due to “amplified” wind loads.
# Effects of Wind on Tower Cranes
Air is a mixture of various gases, where each gas in the mixture has a certain density. When the wind blows, the molecules of the gases in the air gain energy and are moved at different velocities depending on their size and mass. When these molecules encounter a surface in their path, they give some of their energy to the surface and consequently exert pressure onto it. This pressure is defined as:
VP = KVS2, where
• VP is the wind pressure
• K is the density of a gas, which for design purposes is considered constant at 0.613
• VS is the wind speed
As can be seen from the above equation, there exists a squared relationship between win pressure and wind speed. So if you double the wind speed, the wind pressure increases by a factor of four times.
This is a crucial point to note because it underscores how a small increase in wind speed can significantly increase its impact.
Wind speed itself is a function of height, i.e., wind speed increases with height. So the higher you go above the ground, the harder the wind tends to blow.
Since tower cranes are erected at great heights, and sometimes even on top of buildings, the wind can easily reach speed levels where its raw power can become unforgiving and brutal for crane operations. It can destabilize a tower crane or the load on the hook and create potential accident situations. With the center of impact also at a significant distance from the ground, the overturning moment can get further amplified, making the operations even more difficult and dangerous for crane operators.
That’s why it’s recommended that tower cranes should always be operated below maximum permissible speed and crane operators should continuously monitor crane wind speed when performing a lift.
Here, at Crane Warning Systems Atlanta, we sell a variety of crane safety instrumentation systems, including crane Wind Speed Indicator system. Visit our online store to learn more about our crane-exclusive wind speed indicators.
3 views
See All
### Follow us on Social Media
Crane Warning Systems Atlanta
1-877-672-2951 Toll Free
1-770-888-8083 Direct
1-678-261-1438 Fax
[email protected] Email
Be The First To Know
6175 Hickory Flat Hwy
Suite 110-376
Canton, GA 30115
Crane Warning Systems
Warehouse crane
anti two block system crane
wireless anti two block system
1 ton gantry crane
Crane warning systems Atlanta
anti two block system crane Atlanta
warehouse crane Atlanta
wireless anti two block system Atlanta
crane hoist
warehouse crane system
crane trolley
Rayco wylei systems
crane warning systems
Rayco electronics
two block systems | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8231353163719177, "perplexity": 3696.303828588453}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400245109.69/warc/CC-MAIN-20200926200523-20200926230523-00668.warc.gz"} |
https://readsblog.com/midpoint-method-with-matlab/ | # Midpoint Method – Numerical Differentiation with MATLAB
Midpoint Method is numerical method to solve the first order ordinary differential equation with given initial condition. The midpoint method is also known as 2nd order Runge-Kutta method, which improve the Euler method by adding midpoint in step which is given better accuracy by order one. The Midpoint method is converge faster than Euler method. The local error of Midpoint method is O(h3)
At here, we write the code of Midpoint Method in MATLAB step by step. MATLAB is easy way to solve complicated problems that are not solve by hand or impossible to solve at page. MATLAB is develop for mathematics, therefore MATLAB is the abbreviation of MATrix LABoratory.
The formula of Modified Euler method is $y_{n+1}=y_{n}+hf(t_{n}+\frac{h}{2},y_{n}+\frac{h}{2}f(t_{n},y_{n}))$
At here, we solve the differential equation $\frac{dy}{dt}=y-t^{2}+1$ by using Euler method with the help of MATLAB.
% Midpoint method to solve the ordinary differential equation
% Midpoint method fall in the category of Runge-Kutta method of order 2
clear all;
close all;
clc;
f=inline('y-t^2+1');
x0=input('Enter x0=');
y0=input('Enter y0=');
xn=input('Enter upper limit of interval xn=');
h=input('Enter width (equal space) h=');
n=(xn-x0)/h;
fprintf('--------------------------------------------\n')
fprintf(' x y ynew\n');
fprintf('--------------------------------------------\n')
for i=1:n
y1=y0+h*f(x0+h/2,y0+h*f(x0,y0)/2);
fprintf('%f %f %f \n',x0,y0,y1)
y0=y1;
x0=x0+h;
end | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 4, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8545920252799988, "perplexity": 785.532406381261}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-49/segments/1669446710962.65/warc/CC-MAIN-20221204040114-20221204070114-00399.warc.gz"} |
https://www.whoi.edu/what-we-do/understand/departments-centers-labs/po/po-events/po-chapman-lecture-series/2010-chapman-lecture/ | 2010 Chapman Lecture
Wave-driven Circulation in the Nearshore and Coastal Ocean
Tuba Ozkan-Haller
College of Oceanic and Atmospheric Sciences
Fall, 2010
Clark Building, Room 507
Reception to follow
Surface gravity waves propagating towards beaches shoal as they encounter shallower water, and they break in the surf zone. The surf zone region is therefore characterized by decreasing wave momentum with distance towards shore. Surf zone setup and alongshore currents (often referred to as "longshore" currents) are forced by the resulting forces. On alongshore-uniform beaches the resulting setup of the water surface and longshore current are also alongshore-uniform. On alongshore-variable bathymetry the setup displays alongshore non-uniformity, and associated alongshore pressure gradients also contribute to the alongshore momentum balance. Using simulations for several field sites, we find that cases associated with strong longshore currents often indicate a primary balance between the wave forcing and the friction term, with a secondary balance between the advective acceleration and the pressure gradient terms. In the remainder of the talk, this secondary balance is analyzed with the objective of highlighting the effect of the advective terms for conditions of strong longshore currents and weak alongshore variability in the wave forcing. A perturbation analysis is carried out and reveals that a nondimensional parameter (comprised of the length scales of the alongshore variability, the local water depth, longshore current strength and frictional parameter) controls the response of the longshore current to alongshore variability. The resulting simplified model suggests that the nonlinear response is a filtered version of the solution to the linear problem (when nonlinear advective terms are neglected), and the effect of the nonlinearity can be described as an attenuation and spatial shifting of the response to alongshore variability. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8284950256347656, "perplexity": 2701.107968182414}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575541308604.91/warc/CC-MAIN-20191215145836-20191215173836-00034.warc.gz"} |
https://www.physicsforums.com/threads/relative-rates-of-change.148172/ | # Relative rates of change
1. Dec 14, 2006
### flash9286
if you have a*v=s*w how do you get:
delta a/a+delta v/v=delta s/s+delta w/w
can anybody explain why this is true.
2. Dec 14, 2006
### arildno
Well, fiddle about with the expression:
$$(a+\delta{a})(v+\delta{v})=(s+\delta{s})(w+\delta{w})$$
3. Dec 14, 2006
### flash9286
I'm sorry I don't follow
4. Dec 14, 2006
### arildno
What do you not follow?
Do you not understand that the equation av=sw holds for different choices of "a", "s", "v" and "w", including the choices $(a+\delta{a}),(s+\delta{s}),(v+\delta{v}),(w+\delta{w})$?
5. Dec 14, 2006
### flash9286
Nevermind I got it. Thanks for your help
Similar Discussions: Relative rates of change | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9392101764678955, "perplexity": 16513.995388343603}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187825575.93/warc/CC-MAIN-20171023035656-20171023055656-00225.warc.gz"} |
http://nanoscale.blogspot.com/2012/12/quantum-spin-liquids-neat-stuff.html | Thursday, December 20, 2012
Quantum spin liquids - neat stuff!
There is a new result in this week's issue of Nature that is very neat (and my college classmate Young Lee is the PI - small world!). The experiment is an inelastic neutron scattering measurement that looks at a material with the unusual name herbertsmithite, and reports evidence that this material is a "quantum spin liquid". I'll try to break down the physics here into reasonably accessible bite-sized chunks.
First, what is a spin liquid? Imagine having a bunch of localized spins on a lattice. You can picture these like little bar magnets. In this case, the spins are the unpaired d electrons of the copper atoms in the herbertsmithite structure. In general, the spins in a solid (this particular one is an insulator) "talk" to each other via the exchange interaction. What this really means is that there are interactions between the spins so that the spins prefer a particular relative orientation to each other. In this case, the interaction between the electron spins is antiferromagnetic, meaning that for spins on two neighboring Cu atoms, having the spins be oppositely directed saves some energy (17 meV) compared to having the spins aligned. As the temperature is lowered, an ensemble of spins will tend to find whatever configuration minimizes the total energy (the ground state). In a ferromagnet, that will be a state with the spins all aligned with their neighbors. In a perfect antiferromagnet, that would be a state where the spins are all antialigned with their neighbors. Both of these are ordered ground states, in that there is some global arrangement of the spins (with a particular symmetry) that wins at T = 0. The problem in herbertsmithite is, because of the spatial arrangement of the Cu atoms (in a Kagome lattice), it's impossible to have every spin antialigned with all of its neighbors. This is an example of geometric frustration. As a result, even as T gets very low, it would appear that the spins in herbertsmithite never order, even though they interact with their neighbors very strongly. This is an analog to the liquid state, where the molecules of a liquid clearly interact very strongly with their neighbors (they bump right into each other!), but they do not form a spatially ordered arrangement (that would be a solid).
Why a quantum spin liquid? Two reasons. First, I cheated in my description above. While we can talk classically about antialigned spins, we really should say that pairs of spins want to form singlets, meaning quantum mechanically entangled antialigned states with net spin zero. So, you can think of this spin liquid state as involving a big entangled mess of spins, where each spin is somehow trying to be entangled in a singlet state with each of its nearest neighbors. This is very complicated to treat theoretically. Second, the fluctuations that dominate in this situation are quantum fluctuations, rather than thermally driven fluctuations. Quantum fluctuations will persist all the way down to T = 0.
What's special about a quantum spin liquid? Well, the low energy excitations of a quantum spin liquid can be very weird. If you imagine reaching into the material and flipping one spin so that it's now energetically "unhappy" in terms of its neighbors, what you find is that you can start flipping spins and end up with "spinon" excitations that travel through the material, having spin-1/2 but no charge, and other exotic properties. This is described reasonably well here. Importantly, these excitations have effects that are seen in measurable properties, like heat capacity and how the system can take up and lose energy.
So what did the experimenters do? They grew large, very pure single crystals of herbertsmithite, and fired neutrons at them. Knowing the energies and momenta of the incident neutrons, and measuring the energies and momenta of the scattered neutrons, they were able to map out the properties of the excitations, showing that they really do look like what one expects for a quantum spin liquid.
Why should you care? This is a great example of seeing exotic properties (like these weird spin excitations) that emerge because of the collective response of a large number of particles. A single Cu ion or unit cell of the crystal doesn't do this stuff - you need lots of spins. Moreover, this is now a system where we can study what this weird, highly quantum-entangled does - I think it's very very far from practical applications, but you never know. Looks like a very nice piece of work.
paris cox said...
this is fantastic! i can't wait until there is a killer app for this. sure it is at low T, but big things start out small.
give it time and something will become great of it!
Anonymous said...
My impression is that QSLs aren't the real goal of people who study QSLs; the next trick is to dope it and see high-temperature superconductivity, isn't it?
(of course, doping is the hard problem -- ever thus for science)
Anonymous said...
Is this the first example of an experimental quantum spin liquid?
rob said...
i wonder how long it will take some homepath to say their concoctrions are quantum spin liquids?
Douglas Natelson said...
Anon12:19, certainly some people are interested in doping some spin liquids to look for superconductivity. I recall that Anderson and others put about the idea that some of the physics of the cuprates may be spin liquid stuff (resonating valence bonds, etc.). In the case of herbersmithite, though, I don't think that's credible, because the stuff has a big gap (a couple of eV).
Anon2:20, it's the first experimental system that's been probed like this and really seems to have the characteristic excitation spectrum.
joelhelton said...
I'd like to add a comment to Doug's response to Anonymous 2:20.
A good point made very well by Leon Balents (Nature 464, 199) is that experimental signatures of a QSL are difficult to come by since the state is often defined primarily by what it ISN'T (not an ordered magnet, not a spin glass, not a valence bond solid). Therefore there are plenty of reports in the literature of new frustrated magnets with antiferromagnetic interactions that are measured to low temperatures without any evidence of magnetic Bragg peaks, spin glassiness, or muon oscillations. These may well be described as a spin liquid, but in those cases the data really only show a lack of any evidence that it isn't a QSL. This paper is a step forward in the search for experimental signatures of QSLs because the relatively large single crystal samples and new advances in neutron spectroscopy instruments allow for positive evidence in the form of the measured excitation spectrum.
(typo in original post corrected)
Anonymous said...
thanks for posting..
furniture jati said...
Good Job, Thank you for presenting a wide variety of information that is very interesting to see in this artikle
wisata karimunjawa
and jual furniture
or jepara furniture
and toko tenun
Syaiful tenun said...
article from a very amazing, Good Job, Thank you for presenting a wide variety of information that is very interesting to see in this artikle
pemesana furniture jepara |
rute expedisi furniture |
warna furniture jepara |
produk furniture jepara |
furniture jepara |
toko furniture jepara |
toko mebel jepara |
kamar set mewah |
kamar set minimalis |
kamar anak hello kitty |
gebyok pelaminan |
meja kantor jati |
kamar set minimalis |
meja makan jati |
kursi tamu mewah |
kursi tamu mewah |
set kursi tamu |
meja makan jati |
set meja makan |
lemari jati mewah |
almari pakaian |
lemari pakaian 4 pintu |
almari hias ukir jati |
almari hias ukir |
ayunan jati |
ayunan jati jepara |
kursi bale bale |
tenun ikat said... | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8091357946395874, "perplexity": 2228.242501152516}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-11/segments/1424936462316.51/warc/CC-MAIN-20150226074102-00080-ip-10-28-5-156.ec2.internal.warc.gz"} |
https://goldbook.iupac.org/terms/view/I03283 | ## isoionic point
in electrophoresis
https://doi.org/10.1351/goldbook.I03283
The $$\text{pH}$$ value at which the net @[email protected] of an @[email protected] in pure water equals zero.
Source:
PAC, 1994, 66, 891. (Quantities and units for electrophoresis in the clinical laboratory (IUPAC Recommendations 1994)) on page 895 [Terms] [Paper] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3155738115310669, "perplexity": 15923.285941866707}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296949644.27/warc/CC-MAIN-20230331144941-20230331174941-00603.warc.gz"} |
https://www.physicsforums.com/threads/final-angular-velocity-of-a-top.220272/ | # Final Angular Velocity of a Top
1. Mar 6, 2008
### damedesfeuers
1. A top is a toy that is made to spin on its pointed end by pulling on the string wrapped around the body of the top. The string has a length of 64cm and is wound around the top at a spot where its radius is 2.0 cm. The thickness of the string is negligible. The top is initially at rest. Someone pulls the free end of thes stirng, theryb undwinding it and givig the top and an angular acceleration of +12 rad/s^2. What is the final angular velocity of the top when the string is completely unwound?
2. Relevant equations
$$\alpha$$ = $$\omega$$/t
$$\omega$$ = $$\theta$$ /t
Circumfrence: $$\pi$$r^2
3. The attempt at a solution
First I found that the circle's circumference is 4$$\pi$$.
Then I divided 64cm/4$$\pi$$ to find that the rope wraps around 5.09 times.
I know that 360 degrees is equal to 2$$\pi$$radians, so 5.09 x 360 degrees = 1833.5 degrees.
Then 1833.5 degrees x ($$\pi$$ radian / 180 degrees ) = 10.2 radians
Therefore I know the angular displacement, which is from 0 to 10.2 radians
Then I am stumped on how to find the time from that.
I know that I can find the final angular velocity by using the time in the angular acceleration formula. Because Angular acceleration is equal to the final velocity / time. I know this because the initial velocity of the top was zero.
In short I can't figure out how to find the time.
2. Mar 6, 2008
### dynamicsolo
There are two related ways to do this, because one is a method where the time remains concealed.
In the approach you took, you know that the cord is 64 cm long and the circumference it is wrapped around is $$4\pi$$ cm. Therefore the top will turn 5.09 cycles (as you said) or, maybe a bit more helpfully, 64 cm/2 cm = 32 radians (since arclength around a circle is radius times angle).
You can make a kinematic equation for constant angular acceleration analogous to the one for linear motion with constant linear acceleration. Instead of
x_f = (1/2)·a·(t^2) , starting from rest at x=0,
you have
theta_f = (1/2)·(alpha)·(t^2) , starting from rest at theta = 0 .
The top turns through 32 radians by the time the string unwinds and
alpha = 12 rad/sec^2 , so
(t^2) = 2·(32)/12 sec^2 . You can get the time and the final angular velocity from there.
The other way combines the angle and angular velocity equations for constant acceleration to produce an "angular velocity-squared" equation analogous to the "velocity-squared" equation for linear kinematics. Instead of
(v_f)^2 = (v_i)^2 + 2 · (a) · (delta_x) ,
we have
(omega_f)^2 = (omega_i)^2 + 2 · (alpha) · (delta_theta).
You know that omega_i = 0, you know alpha, and you know the total angular displacement is delta_theta = 32 radians. Solve for omega_f .
BTW, I think you dropped a factor here. The 5.09 cycles is correct, but since a cycle is $$2\pi$$ radians, which is slightly more than six, the total number of radians would have to be somewhat over 30 (in fact, exactly 32, as calculated above).
Last edited: Mar 6, 2008
3. Mar 7, 2008
### damedesfeuers
oh thank you, I actually figured it out this morning, but i didn't think I could delete the thread. And I used the method where the time remained concealed! Thank you again! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9591148495674133, "perplexity": 962.1448019590168}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281162.88/warc/CC-MAIN-20170116095121-00083-ip-10-171-10-70.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/6317/is-the-identity-functor-the-terminal-object-of-the-category-of-endofunctors-on | # Is the identity functor the terminal object of the category of endofunctors on $C$?
It seems to me not, since this would seem to imply that for all functors $F$ and all objects $A$ in $C$ there exists a morphism $F(A) \to A$ (making all functors co-pointed?). However, intuitively it seems like the identity functor acts like a terminal object; a monad $M$ on $C$ is a monoid on $[C, C]$ where the "unit" is a natural transformation $η : I \to M$, while for a monoidal set $S$ in Set the unit is a function $e : 1 \to S$. So am I misunderstanding something, or are my intuitions leading me astray?
-
The difference between those two examples is that in $\textbf{Set}$ the monoidal operation is the categorical product (so the identity object is the terminal object), whereas this is not true in the category of endofunctors on $\mathbf{C}$. (I believe the latter has a product if and only if $\mathbf{C}$ does, and then it is the pointwise product. It follows that the terminal object, if it exists, is the functor which sends all objects to $\mathbf{1}$ and all morphisms to the unique morphism $\mathbf{1} \to \mathbf{1}$. In particular, it's not the identity functor.) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9648256897926331, "perplexity": 64.10274348404897}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-18/segments/1461860123023.37/warc/CC-MAIN-20160428161523-00034-ip-10-239-7-51.ec2.internal.warc.gz"} |
http://www.sciencemadness.org/talk/viewthread.php?tid=83470 | Not logged in [Login - Register]
Sciencemadness Discussion Board » Fundamentals » Reagents and Apparatus Acquisition » Is there a solvent I can use to wash my vacuum pump oil reservoir? Select A Forum Fundamentals » Chemistry in General » Organic Chemistry » Reagents and Apparatus Acquisition » Beginnings » Responsible Practices » Miscellaneous » The Wiki Special topics » Technochemistry » Energetic Materials » Biochemistry » Radiochemistry » Computational Models and Techniques » Prepublication Non-chemistry » Forum Matters » Legal and Societal Issues » Detritus » Test Forum
Author: Subject: Is there a solvent I can use to wash my vacuum pump oil reservoir?
Hazard to Others
Posts: 126
Registered: 17-2-2017
Member Is Offline
Mood: No Mood
Is there a solvent I can use to wash my vacuum pump oil reservoir?
I've noticed with time there is colored material accumulated in my vacuum reservoir. I can only assume much of this is perhaps solvents that have oxidizer in the reservoir, or similar material. Changing the oil doesn't seem to clean most of this material out.
Would it be safe or effective to run a solvent like isopropanol or something similar through to clean this? I would use acetone, but would be concerned about chemical compatibility with any seals that may be inside.
Dr.Bob
International Hazard
Posts: 1947
Registered: 26-1-2011
Location: USA - NC
Member Is Offline
Mood: No Mood
The biggest issue with doing that is any solvent left in the pump can wreck it when you restart it. I would just put clean oil in it, run it for 24 hours under vacuum, and then drain that oil and replace. If the material does not dissolve in clean pump oil, then it is likely not hurting much. We have 20 year old Welch pumps that have black crap inside them, that still run fine.
If you take the pump apart to clean it, cleaning the metal parts in degreaser (TCE, PCE, DCM, hexanes, etc) is likely fine, which will remove much of the crud, but then you can make sure the parts are clean and dry before reasssmbling. The rubber seals are not good with most solvents, and alcohols and acetone will not likely dissolve the sludge, but might be OK with the rubber. But I have found that halogenated solvents are the best to dissolve the crap inside the pump, but only on the metal parts. And you don't want to clean the bearings with it, unless you completely clean and dry them and then regrease them.
coppercone
Hazard to Others
Posts: 133
Registered: 5-5-2018
Member Is Offline
How do you degrease stuff like bearings? Use progressively lower boiling point solvents in a soxphlet?
Hazard to Others
Posts: 126
Registered: 17-2-2017
Member Is Offline
Mood: No Mood
Quote: Originally posted by Dr.Bob If the material does not dissolve in clean pump oil, then it is likely not hurting much. We have 20 year old Welch pumps that have black crap inside them, that still run fine.
Well, I had a problem in the past where I just let gunk progressively build up in there, perhaps from letting old oil stay in there from too long, and the pump soon started to jam, stop rotating, and so on. It had some sort of mechanical failure relating to the pump housing and chemicals/residue in the oil. I was hoping to prevent that from happening again.
BromicAcid
International Hazard
Posts: 2986
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Anxious
Depends on what type of pump you have, what materials are in contact with the pump oil. The gaskets in there might not play nice with isopropanol. I've seen people flush the pump with solvent while the pump is running and collect it out of the exhaust. I've seen others remove the oil, replace it with a solvent, run the pump for awhile and suck out the oil with vacuum. In all cases the issue remains how to get ride of the residual solvents? I've seen some seal the pump and pull under vacuum to remove the solvents. Others refill with oil, run for awhile and toss the oil. Again, depends on the pump. Some manufacturers will specify how to 'power flush' their pump and their guidance should be followed.
Shamelessly plugging my attempts at writing fiction: http://www.robvincent.org
alking
National Hazard
Posts: 250
Registered: 11-3-2016
Member Is Offline
Mood: No Mood
I've cleaned mine with DCM before and then let it sit outside in the sun to evaporate. I'd imagine ether would be even better, but I wouldn't want to waste it for that. I only do so because there's already DCM in there anyway so I figure it wouldn't be too acutely damaging to actually flush it with some. If you really want to get it clean you'll have to disassemble it, but I don't think it's really worth the work, vacuum pumps are cheap enough.
If you want to prolongue your vacuum pump's life you could also pickup a water pump and a water aspirator, you can use that for stripping solvents that would cause the most damage and then use the rotary for applications where you need a deeper vacuum.
Dr.Bob
International Hazard
Posts: 1947
Registered: 26-1-2011
Location: USA - NC
Member Is Offline
Mood: No Mood
DCM will kill the gaskets, seals, and metal in pumps, so don't let that get into the pump if possible. That (and TFA and other halogenated solvents) is one of the worst solvents to get inside a pump, which is why traps are good for them. If you try to rine it with a hydrocarbon, the pump can heat up enough to catch fire, which is exciting. Heard about it, never seen it myself, when fire shoots out the exhaust from too much hexane.
Degreasing parts is usually just soaking them in solvent; machine shops and auto supply stores sell various solvents for that. I try not to mess with the bearings unless they are really bad, but pushing new grease into them is almost always a good idea. There are tools for that, but a gloved hand also works.
If the pump is really bad, the only real solution is taking it apart, but we usually wait until it seizes to repair it, routine rebuilds are too expensive for most places, except on air plane engines. A good mechanical pump can be rebuilt several to many times unless really abused. Kinda like an old Ford 302, but simpler.
NeonPulse
National Hazard
Posts: 415
Registered: 29-6-2013
Location: The other end of the internet.
Member Is Offline
Mood: Everclear or Neverclear. Can't decide.
I would agree that disassembly and cleaning the parts is probably the best way to get it clean. It’s what I’ve done a few times with my little 2 stage. Even though it was under $200 to buy (cheap as far as rotary vane vacuum pumps go) I still want to keep it in optimal condition. It is not as hard as I first thought it would be. Mine had actually seized after a few runs in which solvents and water with sodium hydroxide had been sucked into it. It was gunked up good.The fix was easy. Pull apart, degrease and re polish rusted surfaces with 1500 grit sandpaper and a dremel scotchbrite bit. Fresh oil in and off it goes again working as good as the first time it ran. Easy enough to do and it ensures that it will get a pretty long life. Where there is a will there is a way. AllCheMystery! https://www.youtube.com/channel/UCWbbidIY4v57uczsl0Fgv7w?vie... Justin Blaise Hazard to Self Posts: 67 Registered: 5-10-2011 Location: Parts Unknown Member Is Offline Mood: No Mood In my lab we use flushing oil as part of our pump maintenance procedure. It's a lower viscosity oil that, I assume, is better able to dissolve and dislodged contaminants. We drain the old oil, then add the flushing oil, then run the pump for a couple minutes, then drain the flushing oil, and replace with new oil. It may not be able to get out baked-on tar, but it's been pretty effective at preventing its buildup for us. It's a product similar to this one. We use Edward's brand, but that probably isn't important. https://www.amazon.com/VacOil-Grade-Vacuum-Flushing-Fluid/dp... alking National Hazard Posts: 250 Registered: 11-3-2016 Member Is Offline Mood: No Mood Quote: Originally posted by Dr.Bob DCM will kill the gaskets, seals, and metal in pumps, so don't let that get into the pump if possible. That (and TFA and other halogenated solvents) is one of the worst solvents to get inside a pump, which is why traps are good for them. If you try to rine it with a hydrocarbon, the pump can heat up enough to catch fire, which is exciting. Heard about it, never seen it myself, when fire shoots out the exhaust from too much hexane. Degreasing parts is usually just soaking them in solvent; machine shops and auto supply stores sell various solvents for that. I try not to mess with the bearings unless they are really bad, but pushing new grease into them is almost always a good idea. There are tools for that, but a gloved hand also works. If the pump is really bad, the only real solution is taking it apart, but we usually wait until it seizes to repair it, routine rebuilds are too expensive for most places, except on air plane engines. A good mechanical pump can be rebuilt several to many times unless really abused. Kinda like an old Ford 302, but simpler. I agree, like I said I wouldn't use it if there wasn't already DCM in there. An ice bath trap isn't enough to capture it effectively and if I purchased some CO2 every time I'd be spending more on that than I have on the pump, and probably more for what my time is worth going to pick it up. I just get the cheapy pumps and accept that they will die one day. I should take my own advice and pickup a water aspirator setup to strip such things, but my pumps generally last a year or more so ~60$/yr isn't bad.
weilawei
Hazard to Others
Posts: 130
Registered: 3-12-2017
Member Is Offline
Mood: No Mood
A cylinder of CO2 for dry ice only costs me about $40 to fill, and the rental is about$50/year. That way I can run the pump as frequently as I want and avoid putting nasties into it.
alking
National Hazard
Posts: 250
Registered: 11-3-2016
Member Is Offline
Mood: No Mood
Exactly. A cheap rotary vane pump costs ~$60. Why would I spend 50$/yr and 40$everytime I need to fill it when it costs less just to buy a new pump? weilawei Hazard to Others Posts: 130 Registered: 3-12-2017 Member Is Offline Mood: No Mood Or buy a cylinder for 200$ and save 20$every year? It pays for itself in 10 years if you use the absolute cheapest possible pump, but much faster if you use a nicer pump (say, two stages for a start). 2 stage pumps start around 130$, which already makes it cheaper to buy CO2/rent the cylinder. If you buy it, you break even in just under 27 months.
[Edited on 1-6-2018 by weilawei]
alking
National Hazard
Posts: 250
Registered: 11-3-2016
Member Is Offline
Mood: No Mood
Wouldn't you save 50/yr that way, where do you get 20? (nevermind, got in before your edit) However sure, but how many times do you refill your cylinder per year? 1.5 refills and you've paid for the pump, and that assumes the pump only lasts a year.
You're also expending electricity and additional equipment costs to freeze the CO2, how are you even doing so for that matter? Most of us don't have the equipment for that. Actually if you can freeze CO2 then why do you even need the CO2 to cool the trap in the first place?
If I wanted to protect an expensive higher end vacuum pump I simply woudn't use it to strip solvents and instead pickup a cheaper dedicated pump just for that, you can even get an aspirator setup and not have to worry about it eventually dying from corrosion/worn gaskets.
[Edited on 1-6-2018 by alking]
DavidJR
International Hazard
Posts: 653
Registered: 1-1-2018
Location: Scotland
Member Is Offline
Mood: Anxious
Quote: Originally posted by alking Wouldn't you save 50/yr that way, where do you get 20? (nevermind, got in before your edit) However sure, but how many times do you refill your cylinder per year? 1.5 refills and you've paid for the pump, and that assumes the pump only lasts a year. You're also expending electricity and additional equipment costs to freeze the CO2, how are you even doing so for that matter? Most of us don't have the equipment for that. Actually if you can freeze CO2 then why do you even need the CO2 to cool the trap in the first place? If I wanted to protect an expensive higher end vacuum pump I simply woudn't use it to strip solvents and instead pickup a cheaper dedicated pump just for that, you can even get an aspirator setup and not have to worry about it eventually dying from corrosion/worn gaskets. [Edited on 1-6-2018 by alking]
You don’t need anything special to freeze CO2, all you need is, well, boyle’s law.
weilawei
Hazard to Others
Posts: 130
Registered: 3-12-2017
Member Is Offline
Mood: No Mood
Quote: Originally posted by alking Wouldn't you save 50/yr that way, where do you get 20? (nevermind, got in before your edit) However sure, but how many times do you refill your cylinder per year? 1.5 refills and you've paid for the pump, and that assumes the pump only lasts a year.
So far, it looks like perhaps 2x50 lb fills per year. I've been using the cylinder for about half a year now, or about 100lbs of CO2/year. My math did assume once a year, but I also make heavy use of it, for the cold trap as well as other cooling. I do also keep a dewar of chilled isopropanol, so I don't always need the dry ice.
Quote: If I wanted to protect an expensive higher end vacuum pump I simply woudn't use it to strip solvents and instead pickup a cheaper dedicated pump just for that, you can even get an aspirator setup and not have to worry about it eventually dying from corrosion/worn gaskets.
You raise an excellent point, and this is in fact what I do. I have an aspirator, and that serves for stripping particularly obnoxious vapors (excessively low BP, highly corrosive, etc.). I won't use the pump for pulling bulk solvent out of something (drying a product is one thing, but I'd rather distill over solvent than force it through my pump). I frequently recover some small amount of product from my cold trap that might otherwise be lost. If it's not product, it's still something I don't want in my pump.
As to freezing CO2, my tank is filled with a liquid (gas headspace) and a siphon tube extends internally to the bottom. I use a small snow horn and pressure gage to blow the dry ice into a "sock" for collection. Just crack the valve and collect!
[Edited on 2-6-2018 by weilawei]
Sciencemadness Discussion Board » Fundamentals » Reagents and Apparatus Acquisition » Is there a solvent I can use to wash my vacuum pump oil reservoir? Select A Forum Fundamentals » Chemistry in General » Organic Chemistry » Reagents and Apparatus Acquisition » Beginnings » Responsible Practices » Miscellaneous » The Wiki Special topics » Technochemistry » Energetic Materials » Biochemistry » Radiochemistry » Computational Models and Techniques » Prepublication Non-chemistry » Forum Matters » Legal and Societal Issues » Detritus » Test Forum | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.16907481849193573, "perplexity": 4335.116359356216}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195528141.87/warc/CC-MAIN-20190722154408-20190722180408-00467.warc.gz"} |
https://socratic.org/questions/a-car-travels-65-km-in-1-hour-what-is-its-average-speed-in-meters-per-second#570831 | Physics
Topics
# A car travels 65 km in 1 hour. What is its average speed in meters per second?
Mar 11, 2018
$\text{18.06 m/s}$
#### Explanation:
$\text{Average speed" = "Total distance"/"Total time}$
$\left\langleV\right\rangle = \text{65 km"/"1 hour}$
$\left\langleV\right\rangle = \left(65 \cancel{\text{km" × "1000 m"/cancel"km")/(1 cancel"hour" × "3600 s"/cancel"hour}}\right)$
<< V >> = ("65000 m")/"3600 s" = "650 m"/"36 s" = color(blue)"18.06 m/s"
Mar 11, 2018
1.81 meters per second
#### Explanation:
1 km = 1000 m
1 hour = 60 minutes
1 minute = 60 seconds
$\frac{65 k m}{1 h o u r} \cdot \frac{1000 m}{1 k m} \cdot \frac{1 h o u r}{60 \min} \cdot \frac{1 \min}{60 \sec}$ = $\frac{1.81 m}{s}$
Mar 11, 2018
$\text{18.06 m/s}$
#### Explanation:
$\text{65 km = 65000 m}$
$\text{1 hr = 60 mins = 3600 secs}$
$\text{speed" = "distance" / "time}$
$\text{speed" = "65000 m" / "3600 secs}$
$\text{speed = 18.06 m/s}$
##### Impact of this question
5849 views around the world | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 13, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5117384791374207, "perplexity": 20343.5657582717}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-40/segments/1664030337516.13/warc/CC-MAIN-20221004152839-20221004182839-00777.warc.gz"} |
https://brilliant.org/problems/collision-force/ | # Collision Force
A car having a mass of $2 \text{ Mg}$ strikes a smooth, rigid sign post with an initial speed of $30 \text{ km/h}$. To stop the car, the front end horizontally deforms $0.2 \text{ m}$. If the car is free to roll during the collision, determine the average horizontal collision force causing the deformation.
× | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 7, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.21567191183567047, "perplexity": 1043.0696126635794}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986647517.11/warc/CC-MAIN-20191013195541-20191013222541-00008.warc.gz"} |
https://franklin.dyer.me/notes/note/Truth_values_in_a_topos | ## Franklin's Notes
### Truth values in a topos
In a topos $\mathscr E$, the arrows $1\to\Omega$ from the terminal object to the subobject classifier are called the truth values. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7658863663673401, "perplexity": 806.1683774779325}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500368.7/warc/CC-MAIN-20230207004322-20230207034322-00437.warc.gz"} |
http://openstudy.com/updates/5162cc67e4b0c2e460704558 | ## A community for students. Sign up today!
Here's the question you clicked on:
55 members online
• 0 viewing
## R00nnYBraiNsbiG one year ago -3|x-2|+10=12 x = 1 and x = 5 x = −1 and x = −5 x = −9 and x = 3 No Solution Delete Cancel Submit
• This Question is Closed
1. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
@AravindG HELP ME PLEASE STEP BY STEP
2. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
$-3|x-2|=2$ now we square this.. the only way to get rid of the absoute sign is to square it
3. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
or make two equations out of it.
4. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
ok wait spuare the hole thing
5. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
yes see the above simplified orm
6. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
$\left[-3|x-2|\right]^2=2^2$
7. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
ok wat about the + 10
8. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
I subtracted it from the two sides
9. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
notice that the right side became 12-10=2
10. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
where did u get the 12 frm
11. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
@electrokid
12. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
where did u get the 12 from
13. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
$-3|x-2|+10=12\qquad\text{....given}\\ \qquad\qquad-10\quad-10$
14. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
ok srry im just learning this ok and then gives u this [−3|x−2|]^2=2^2
15. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
that is ok. well, this first gives $-3|x-2|=2$ so, we the square it like you just wrote above
16. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
yes
17. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
$(-3)^2(x-2)^2=(2^2)$ notice that the absolute sign has disappeared
18. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
so 9*2x-4=4
19. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
or to avoid squaring, you can remove the abolute sign in two ways...... $-3|x-2|=2\implies|x-2|=-{3\over2}$
20. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
how did u get 3/2
21. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
my bad... $\Large{|x-2|=\color{red}{-}{2\over3}}$
22. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
ooh its ok but how did u get that
23. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
divide the two sides by "3"
24. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
ok
25. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
${-3|x-2|\over-3}={2\over-3}$
26. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
this gives the above form.. now, by definition of ABSOLUTE value, can it ever become negative?
27. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
HEY STOP STOP STOP I WROTE THE PROBLEM DWN WRONG SRRY THIS IS THE PROBLEM −3|2x + 6| = −12
28. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
ok... you mean no "10" in there?
29. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
yea
30. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
this is so much different than what you first asked for
31. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
ok.. proceeding similarly, get the absolute quantity on its own...
32. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
ik b/c its 2 differnt problems in one
33. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
$\Large{-3|2x-6|=-12\\\text{divide both sides by -3}\\ |2x-6|=4\\\text{to get rid of absolute sign, we get two possible answers}\\\;\\ 2x-6=4\qquad{\rm AND}\qquad2x-6=-4\\ 2x=4+6\qquad\qquad\qquad2x=-4+6\\ 2x=10\qquad\qquad\qquad\quad2x=2\\ \boxed{x=5}\qquad\qquad\qquad\quad\boxed{x=1}}$
34. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
check, plug in "x=" those numbers in the given problem on the left side. That should give you the right side.
35. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
thanks
36. electrokid
• one year ago
Best Response
You've already chosen the best response.
1
did you understand?
37. R00nnYBraiNsbiG
• one year ago
Best Response
You've already chosen the best response.
0
yes
38. Not the answer you are looking for?
Search for more explanations.
• Attachments:
Find more explanations on OpenStudy
##### spraguer (Moderator) 5→ View Detailed Profile
23
• Teamwork 19 Teammate
• Problem Solving 19 Hero
• You have blocked this person.
• ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9999761581420898, "perplexity": 16094.664786633519}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-06/segments/1422115855094.38/warc/CC-MAIN-20150124161055-00100-ip-10-180-212-252.ec2.internal.warc.gz"} |
http://mathhelpforum.com/math-challenge-problems/83640-differential-equation.html | 1. ## A differential equation
I won't be posting new problems for a couple of weeks. This one is nice:
Suppose $n \geq 1$ and $f: (a,b) \longrightarrow \mathbb{R}$ is a $C^n$ function (see here for the definition) and $f(x)f'(x)f''(x) \cdots f^{(n)}(x) = 0,$ for all $a < x < b.$ Show that $f$ is a polynomial of degree at most $n-1.$
2. Originally Posted by NonCommAlg
I won't be posting new problems for a couple of weeks. This one is nice:
Suppose $n \geq 1$ and $f: (a,b) \longrightarrow \mathbb{R}$ is a $C^n$ function (see here for the definition) and $f(x)f'(x)f''(x) \cdots f^{(n)}(x) = 0,$ for all $a < x < b.$ Show that $f$ is a polynomial of degree at most $n-1.$
if we assume that f(x) is a polynomial of the degree n-1,
we get,
$\large f^{n}(x^{n-1})=0$
If f(x) has the degree n-2,
then the (n-1)th derivative of f becomes zero.
The same holds for all degrees <(or equal to) (n-1)
hence, the given product always becomes vanishes.
However, if we now start making the degrees > (n-1)
Lets assume that the function is a polynomial of degree n.
I'll take the simplest case here. assuming
$\large f(x)=x^{n}$
Then, the nth derivative of the function:
$\large f^{n}(x^{n})=n!$
And all the other derivatives would be of the form:
$\large f^{r}(x^{n})=n(n-1)(n-2)...(n-r+1)x^{n-r}$
it follows that
that none of the derivatives will now be zero hence, the product cannot be zero. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 18, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9773522019386292, "perplexity": 284.0680460849286}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218188824.36/warc/CC-MAIN-20170322212948-00459-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://gitter.im/KaTeX/KaTeX?at=5f05948764ef9d04b29ca2d9 | ## Where communities thrive
• Join over 1.5M+ people
• Join over 100K+ communities
• Free without limits
##### Activity
• Jan 03 2016 02:45
@kevinbarabash banned @acx01b
gugar20
@gugar20
Hi there, does anyone know how to use actual math in a <Latex> component in React? The output looks like a mix of text and math. Thanks!
nidupb
@nidupb
Hi guys, noobs here, I'm trying to display this formula with katex, but I can't render the % symbol :\%_{acquis} = \frac{I}{V_{prem}+I}. If I replace \% by a letter, it works fine.
what am I doing wrong ?
Eric Eastwood
@nidupb Does it look correct here in Gitter? $\%_{acquis} = \frac{I}{V_{prem}+I}$ https://gitlab.com/gitlab-org/gitter/webapp/-/blob/develop/docs/messages.md#katex-math-formulas
Perhaps it's the renderer you are using
nidupb
@nidupb
yes it does, I actually just found out a way to render it correctly : $$\\%\_{acquis} = \frac{I}{V_{prem}+I}$$
Eric Eastwood
@nidupb Thanks for the follow-up!
Anshul Singhvi
@asinghvi17
Hey, so this might be a long shot, but I'm working on a plotting package in Julia, and I wanted to use KaTeX to typeset math, and extract glyph positions, scales and offsets. Is there a way I can do that through the KaTeX API?
Dima@finstreet
@dvogtfstr
Hey, how is it possible to change the font to an another font of the lib? I.E. to Katex_SansSerif? If I try it, it change only the plus and minus signs 🤔 Pls help
vingt100-82
@vingt100-82
Hi, is there any command who permit to align left : like this one \begin{left}
thx
Ricardo Navarro
@rnavarro92_gitlab
hi
exist the webpage support functions for v0.7.1 ?
lochiwei
Is it possible to repeat a command n times in KaTeX?
Floris
@florisdf
What would be the easiest way to calculate the coordinates of the bounding box (width, height, left x, top y) of a symbol or sub-expression in a certain rendered expression, given the path to obtain that symbol/sub-expression from the KaTeX build tree?
KibikaJ
@KibikaJ
Hi @ronkok; and @kevinbarabash . Is it possible to use jsPDF to convert html KaTeX rendered equations and graphics to a PDF. Kindly suggest for the way forward. Thank you.
Christophe Calvès
@chrilves
Hi everyone, I try to find a way to prevent KaTeX from breaking inline math formulas. Is it possible?
KibikaJ
@KibikaJ
Hi
Hi @chrilves
Ed Darnell
@freemaths
@KibikaJ not quite what you asked for but I have found "print" works well in chrome. If you print a page containing katex and select "print to pdf" then the result is a nicely rendered PDF.
KibikaJ
@KibikaJ
Thank you so much. However, @freemaths , is there a way I can mimic chrome print mechanism in JavaScript or jQuery to print contents of a div containing katex instead of a whole html page?
Ed Darnell
@freemaths
@KibikaJ not that I am aware of. I haven't found any published APIs but you may be able track down open-source. Perhaps try asking on the chromium project?
Ed Darnell
@freemaths
@KibikaJ forgot to mention - what I do is render a different version of the page when prinitng. So you could just print one div if you want. It is a cumbersome mechanism if you only want a quick conversion of something small to PDF. It works fine if you want a PDF version of maths to upload and publish.
KibikaJ
@KibikaJ
@freemaths , I am really in a dilemma, my conversion may not involve so many pages upto a maximum of 20 pages otherwise less than 12 pages in many cases.
@freemaths could you be kind enough to give me your code to enable me make some progress. my email: [email protected] , thanks in advance.
KibikaJ
@KibikaJ
@freemaths Have you tried SlimmerJS before
Ed Darnell
@freemaths
@KibikaJ my development is all in React so might not be helpful. The key parts are: if (this.state.print) {
setTimeout(()=>{
window.print()
this.setState({print:false})
},2000)
} and if (this.state.print) return <div ref={r=>{this.maths=r}}>
{this.state.title&&<h5><Maths auto={true}>{this.state.title}</Maths></h5>}
<Maths width={this.state.width} auto={true}>{this.state.maths}</Maths>
</div> My maths class just renders my maths using Katex. I found the timeout was required to give the print page time to render.
KibikaJ
@KibikaJ
Thanks, so if you want to print content in a div
@freemaths I will attempt to mimic the code in JavaScript
KibikaJ
@KibikaJ
@freemaths, Hi, all math equations in KaTeX rendering on pdf appears to repeat with weird square root signs
nicolas moreau
@niikko_gitlab
Hi, I can not render a url link using katex. The command \href{https://katex.org/}{\KaTeX} is displayed in plain text. I set trust=true, is there something else to do ?
Kevin Barabash
@kevinbarabash
Sorry for not watching this channel lately. We've enabled GitHub Discussions in the KaTeX repo, see https://github.com/KaTeX/KaTeX/discussions.
@KibikaJ for PDF generation you may want to try puppeteer.
KibikaJ
@KibikaJ
Thanks. Let me take a look at it. I hope it will meet my basic needs.
Professorlopes
@professorlopes_gitlab
$\dfrac{3}{7}$
mahesh99599
@mahesh99599
Hi, I'm not able to parse Katex "$\Ia = \sum{i=1}^\infty\ointM r{Q}^{2}\theta \,dA$ or$\begin{Bmatrix} F = 12 N \\cr\tau = 26 N.m\end{Bmatrix}$" and it's giving "KaTeX parse error: Expected 'EOF', got '\' at position 8: \Ia = \̲\̲sum{i=1}^\inf… or KaTeX parse error: Expected 'EOF', got '\' at position 1: \̲\̲begin{Bmatrix} …", Can anyone help me in this, Thanks in advance
Ron Kok
@ronkok
Well, \Ia is not a LaTeX function. Neither is \ointM. You probably want to put "or" into text mode, not math mode. You are probably looking for something like: "$Ia = \sum_{i=1}^\infty\oint M r{Q}^{2}\theta \,dA\; \text{or} \begin{Bmatrix} F = 12\, \mathrm{N}N \ \tau = 26\, \mathrm{N\cdot m}\end{Bmatrix}$"
mahesh99599
@mahesh99599
@ronkok Thank you soo much for your quick response, It solved my issue. Thanks once again...!
mahesh99599
@mahesh99599
Hi, Is there a way to include commas in Katex synatx without breaking the columns in CSV file?
Dominique
@dpo
Hi. I’ve been testing KaTeX support in Gitter and I’m finding that some symbols look off. For instance, the following matrix has tiny brackets:
\begin{bmatrix} A & B \\ C & D \end{bmatrix}
$\begin{bmatrix} A & B \\ C & D \end{bmatrix}$
How do we get the proper rendering?
Dominique
@dpo
Also how do you render in display style?
James Carlson
@jxxcarlson
Hi there! I've been using KaTeX in an app I am working on -- everything great except that display math equations are not centered. Here is an example:
https://zipdocs.lamdera.app/p/pu142-ac656
I am using KaTeX in a custom element. The code is the same as in in another app where the display is centered, so I am at a loss to know what I am doing wrong.
PS. The app works in Chrome and Firefox, but the content window won't scroll in Safari
James Carlson
@jxxcarlson
Never mind re the above. It was my bad, and it is fixed now. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 3, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6659205555915833, "perplexity": 2484.4155784778}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-40/segments/1664030337516.13/warc/CC-MAIN-20221004152839-20221004182839-00256.warc.gz"} |
https://www.zigya.com/study/book?class=12&board=nbse&subject=Biology&book=Biology&chapter=Microbes+in+Human+Welfare&q_type=&q_topic=Microbes+As+Biocontrol+Agents+&q_category=&question_id=BIENNT12132118 | ### Chapter Chosen
Microbes in Human Welfare
### Book Store
Currently only available for.
CBSE Gujarat Board Haryana Board
### Previous Year Papers
Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12
A person likely to develop tetanus is immunised by administering
• preformed antibodies
• wide spectrum antibiotics
• weakened germs
B.
preformed antibodies
In passive immunity, the antibodies are produced in some other organism (eg, horse) in response to the given antigen,.These antibodies are then injected into the human body at the time of need. This is known as inoculation, eg, persons infected by tetanus, rabies, Salmonella and snake venom are given the sufficient amount of antibodies, so that they can survive.
In passive immunity, the antibodies are produced in some other organism (eg, horse) in response to the given antigen,.These antibodies are then injected into the human body at the time of need. This is known as inoculation, eg, persons infected by tetanus, rabies, Salmonella and snake venom are given the sufficient amount of antibodies, so that they can survive.
504 Views . 3 Shares
Which bacterium is responsible for the formation of curd from milk?
Lactobacillus (Lactic acid bacteria).
2900 Views . 6 Shares
What is the difference between rum and whisky ?
Rum is obtained by the fermention of sugarcane juice or molasses. It is fermented for a shorter period of time
while
whisky is obtained by fermentation of grains like wheat, corn,barley and rye. The fementation is done for a longer period of time.
681 Views . 12 Shares
Give the source of invertase enzyme (sucrase).
Saccharomyces cerevisiae
607 Views . 6 Shares
What is brewing ?
Brewing is a complex fermentation process, which involves the production of malt beverages such as beer, ale and stout. Saccharomyces cerevisiae is used for the process of fermentation.
587 Views . 5 Shares
Name one micro-organism which is used in bakery.
Yeast .
622 Views . 11 Shares
Do a good deed today
Refer a friend to Zigya | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.37076300382614136, "perplexity": 13727.860929824548}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794872114.89/warc/CC-MAIN-20180528072218-20180528092218-00633.warc.gz"} |
http://math.stackexchange.com/questions/119882/hahn-banach-extend-the-functional-by-continuity | # Hahn-Banach. Extend the functional by continuity
Let $E$ be a dense linear subspace of a normed vector space $X$, and let $Y$ be a Banach space. Suppose $T_{0}\in\mathcal{L}(E,Y)$ is a bounded linear operator from $E$ to $Y$. Show that $T_{0}$ can be extended to $T\in\mathcal{L}(X,Y)$ (by continuity) without increasing its norm.
I have a dumb question: Given the Hahn-Banach theorem, what's to prove here? It seems to be the immediate consequence of that theorem. If I am wrong, please show me how to prove this. Thank you!
-
Hahn-Banach has nothing to do with the problem at hand (and one only speaks of functionALs if $Y$ is the ground field). The key words here are uniform continuity and completeness of $Y$. – t.b. Mar 14 '12 at 1:59
@t.b. Thanks. I still need to think about this. I agree that I can not apply that theorem directly. – user16859 Mar 14 '12 at 4:04
Yes, a bounded linear operator is Lipschitz continuous by definition: $\|Tx_1 - Tx_2\|_Y \leq \|T\|\,\|x_1 - x_2\|_X$. Lipschitz continuity implies uniform continuity. The reason I phrased it the way I did is that it is a general fact that if $f_0: D \to Y$ is uniformly continuous where $D \subset X$ is dense in a metric space $X$ and $Y$ is a complete metric space then $f_0$ admits a unique extension to a (uniformly) continuous $f: X \to Y$. Applying this in the present situation you get the extension $T$ from this general fact and linearity of $T$ follows from uniqueness of the extension – t.b. Mar 15 '12 at 2:36
Oh, no, no Tietze at all. It's exactly the same argument as the one azarel outlines. You'll see that you won't use that $T_0$ is linear when you define $T$ (or $f$ as azarel write), you'll only need that when verifying that it is linear... (and since nobody gave you a vote so far, here we go :)) – t.b. Mar 15 '12 at 2:50
That's a consequence of the reverse triangle inequality and the definition of $x_n \to x$: $|\|x_n\| - \|x\|| \leq \|x_n - x\| \to 0$, so $\|x_n\| \to \|x\|$. – t.b. Mar 15 '12 at 6:17
Hahn-Banach only apply if $Y=\mathbb R$. For this particular problem you want to show that if $(x_n)$ converges to $x$ then $T_0(x_n)$ is a Cauchy sequence and then define $f(x)$ as the limit of the sequence. Finally you need to show that the map is a well-defined bounded linear function. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9881006479263306, "perplexity": 106.01476904260238}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398466260.18/warc/CC-MAIN-20151124205426-00344-ip-10-71-132-137.ec2.internal.warc.gz"} |
http://openstudy.com/updates/556c40c4e4b050a18e83bd42 | Here's the question you clicked on:
55 members online
• 0 viewing
## rvc one year ago how to find ip address ? Delete Cancel Submit
• This Question is Closed
1. rvc
• one year ago
Best Response
You've already chosen the best response.
1
@Opcode @sasogeek @wio
2. rvc
• one year ago
Best Response
You've already chosen the best response.
1
@osanseviero
3. anonymous
• one year ago
Best Response
You've already chosen the best response.
0
Are you looking to find your public IP address? If so, http://www.whatismypublicip.com/
4. rvc
• one year ago
Best Response
You've already chosen the best response.
1
what if i have to find the ip address of another user ? well thanks for that @Alekcei
5. anonymous
• one year ago
Best Response
You've already chosen the best response.
0
You can grab someone's IP if you're using a peer-to-peer application, but what you're asking for is something more complex. You can't just simply get someone's IP
6. rsmith6559
• one year ago
Best Response
You've already chosen the best response.
0
If someone is, or was in the last 5 seconds or so, their IP address will appear in "netstat -an" ( same for *nix and Windows ). So if you're running a webserver, you could check for connections to port 80.
7. anonymous
• one year ago
Best Response
You've already chosen the best response.
0
@rsmith6559 I'm pretty sure he's asking how to get someone's IP only knowing their name on Facebook, Steam, OpenStudy, etc.
8. rsmith6559
• one year ago
Best Response
You've already chosen the best response.
0
I'd bet on it too, but it wasn't in the question.
9. rvc
• one year ago
Best Response
You've already chosen the best response.
1
Its not about that i want to find someones number which i dont have i think that through ip i will get it i need it urgent :(
10. rvc
• one year ago
Best Response
You've already chosen the best response.
1
@Alekcei u r right but its not any of those sites you mentioned
11. anonymous
• one year ago
Best Response
You've already chosen the best response.
0
$\ln 45\cot 45$
12. anonymous
• one year ago
Best Response
You've already chosen the best response.
0
What sites do you have in mind? Certain sites, and applications sometimes leak a user's IP. For instance Skype is well know to leak a user's IP. (They still have not patched it, and it has been years.)
13. rvc
• one year ago
Best Response
You've already chosen the best response.
1
kik
14. anonymous
• one year ago
Best Response
You've already chosen the best response.
0
You could code a website that logs a person's IP. Send the link over /Kik/ and tell them to click on it.
15. rvc
• one year ago
Best Response
You've already chosen the best response.
1
ah the person is offline cant i find without their help?
16. anonymous
• one year ago
Best Response
You've already chosen the best response.
0
I do not think so.
17. rvc
• one year ago
Best Response
You've already chosen the best response.
1
Ah :(
18. Not the answer you are looking for?
Search for more explanations.
• Attachments:
Find more explanations on OpenStudy
##### spraguer (Moderator) 5→ View Detailed Profile
23
• Teamwork 19 Teammate
• Problem Solving 19 Hero
• You have blocked this person.
• ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9975637793540955, "perplexity": 9595.743818450745}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988720356.2/warc/CC-MAIN-20161020183840-00203-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://www.arpinvestments.com/insights/natural-gas-dynamics | Thematic, innovative and bespoke investment solutions and thinking
# Natural Gas Dynamics
## The objectives of this research paper
This research paper is an extension of an earlier research paper on oil (see Paradigm Shifts in Oil, dated 14 July, 2015), but the two can easily be read independently of each other. Whereas the earlier paper looked at the global oil price outlook, this paper will focus on natural gas prices.
We publish investment strategies and opportunities in our research papers. This research paper is available to professional investors as part of ARP+ subscription.
## The variation in regional gas prices is significant
Natural gas prices are, unlike oil prices, not global in nature. Prior to the financial crisis most gas prices traded in a relatively narrow range; however, around 2010, as the global economy began to recover from the great recession, natural gas prices began to diverge quite significantly (chart 1). The U.S. proxy (Henry Hub) has traded at the bottom of the range in recent years – almost certainly due to the shale gas revolution. The Japanese, on the other hand, have suffered from very high gas prices in the aftermath of the Fukushima disaster, when the Japanese closed all their nuclear facilities and, as a result, became more dependent on coal and natural gas to fuel their power plants.
Here in Europe we also appear to have paid ‘over the top’ for natural gas in recent years – at least when compared to U.S. prices. (For our UK readers, we note that NBP in chart 1 are UK gas prices.) Apart from the annoyance associated with paying substantially more than our U.S. friends for heating our homes, the higher gas prices in Europe have a serious economic effect, and one that is not good for Europe. Natural gas is a major source of fuel for power plants all over the world, so higher natural gas prices here in Europe translate into higher electricity prices (chart 2). Needless to say, electricity is a major cost in many industries, and therefore the price of it affects competiveness.
Chart 2 only reflects what households – not industry - pay for electricity, and local taxes may explain part of the price variations - not that it makes the loss of competitiveness any less painful, but that is another story. For example, in my home country Denmark (which for a change is no. 1 in an international league table – just not the sort of league table you want to be leading), household use of electricity is taxed.
Having said that, no electricity taxes are large enough to fully explain the massive difference in electricity prices across the world (or so we have been informed). Of great significance is the big spread in fuel costs.
## The correlation between oil and gas prices
Historically, oil and gas prices have been quite highly correlated (chart 3). They are both important heating fuels and, until relatively recently, both oil and gas have been significant fuels in power plants, which is one of the key reason why the two have correlated as much as they have.
Having said that, since the first oil crisis in 1973, the use of oil in power plants has been on a near constant decline. In 1973 25% of all power generated globally was based on oil. Today the same number is 5%, and in many OECD countries it is below 1%.
Around the financial crisis certain things happened. The powerful rally in energy prices in 2007-08 kicked off the shale gas revolution in the United States. We note that, since 2009, the use of coal as a fuel in U.S. power plants has fallen 10% whereas the use of natural gas has increased more than 20%.
In the spring of 2011 the Fukushima earthquake and tsunami rattled Japan. All but two nuclear reactors were shut down within 12 months, and the remaining two have since been closed. In Germany the government decided to phase out nuclear power over 10 years - 8 of 17 reactors have since been closed and the government is committed to closing the rest by 2022.
The result?
Gas prices have not participated in the recent oil price slide due to the combination of more widespread use of natural gas in the U.S., much stronger demand from Japan and somewhat stronger demand from Europe.
## The Russian bull
Russia exports substantial amounts of gas to Europe every year, accounting for almost 30% of total consumption across Europe (chart 4). We note that the corresponding number for the EU is 43% (in 2013).
The overall (political) relationship with Russia has deteriorated in recent years, following the Russian involvement in the civil war in Ukraine. 50% of Russian exports to Europe run via pipelines in Ukraine, putting nearly 15% of European gas supplies at a serious risk.
This raises the relevant question(s) whether one can trust that Russia will honour its contractual obligations and whether we should consider other options here in Europe?
The obligations first. Almost all Russian gas exports to Europe are sold on long-term contracts - varying from 10 to 35 years in length. The contracts are legally binding and subject to international arbitration. All contracts contain a take-or-pay clause which requires buyers to pay for a minimum annual quantity of gas, irrespective of whether they take delivery or not. Post 2008 the take-or-pay level in many of these contracts was reduced from 85% to 70% (chart 5).
At an assumed 70% take-or-pay level, in 2015 European buyers are committed to purchase more than 125 billion m3 (bcm) of gas from Russia. There are significant limitations on the options to reduce the volumes in these contracts, or to terminate contracts before expiry.
As a consequence, in the short to medium term, dramatic changes are unlikely. Russia is likely to continue to deliver gas to Europe. If nothing else, they desperately need the income – oil and gas exports to Europe account for over 50% of Russia’s federal budget income. On the other hand, Europe is likely to continue to buy its gas in Russia despite all the shenanigans in the ongoing verbal war between the two. In the short to medium term, there simply are no alternatives.
## The long-term alternatives to Russia
In the long run, several things can happen as a result of recent events; the nuclear deal with Iran probably being the most significant development in more recent times. Iran – not Russia as many believe – has the largest gas reserves in the world, and a more cordial relationship between Iran and the West could open for a new pipeline to Europe.
There is already a pipeline between Tabriz in Iran and Ankara in Turkey (which does not cross ISIS controlled country). The Iranian ambition is to extend that pipeline to Italy and from there to the rest of Europe (see for example here). An extension of the Tabriz-Ankara pipeline alone would allow Europe to import 30-40 bcm per year from Iran and would cost €6 billion to build.
According to estimates from the European Parliament, Iran would be capable of exporting well over 150 bcm per year, as long as the required pipeline network is available, rivalling Gazprom’s 140 bcm annual exports to the EU. An Iranian entry into Europe would seriously weaken Russia’s hand in the ongoing negotiations with Europe.
We also note that Azerbaijan – another major proprietor of gas reserves - has long been talking about improving its network of pipelines. Azerbaijan happens to be located right next to Iran (to the north), and the two could possibly work together on the extension of the Turkish pipeline – also known as the Persian pipeline (see here).
Increased competition from Iran and Azerbaijan would most likely lead to a meaningful fall in the premium on natural gas prices in Europe and will be the last thing the Russians would want. Two things can happen as a result. Either the Russians will do anything conceivable to obstruct the construction of such a pipeline, or they will become more cooperative in the talks with Europe, trying their very best to keep a valuable client.
Perhaps Russia has already spotted the writing on the wall and realise that they should not rely on Europe for such a major share of income. Moscow recently signed a contract with Beijing, providing China with 30 years of energy supplies and Russia securing $400 billion of income. The deal with Beijing will allow Moscow to be more aggressive vis-à-vis the Europeans in Ukraine. We also note that the contract was signed before the breakthrough in the talks between Iran and the West. ## The consequence for gas prices Almost whatever way the Russians decide to respond to the Iranian/Azerbaijani pipeline plans, the long term consequence would probably be a lower price premium on natural gas in Europe v. Henry Hub. However, the short to medium term implications could be vastly different. In the July research paper on oil we concluded that oil prices are likely to trade in a relatively narrow range going forward, and we estimated that range to be$50-80 per barrel approximately. (Note: We should probably point out that we always refer to Brent when we refer to oil prices). As far as natural gas prices are concerned, we draw precisely the opposite conclusion. We think there are enough incidents ‘in the pipeline’ for natural gas prices to prove unusually volatile over the next several years.
The incidents we are referring to may impact the price of natural gas both positively and negatively without necessarily having a major effect on oil prices (a potential war between Sunni Saudi Arabia and Shia Iran being the main exception) and could include (Note: NG meaning natural gas):
• An escalation of the Ukrainian crisis (NG prices in Europe to rise – possibly dramatically so).
• A reversal of the non-nuclear strategy in Japan and/or Germany (NG prices in Japan and/or Europe to fall).
• A sudden deterioration in the relationship between Iran and the West after a period of normalisation (NG prices in Europe to rise).
• An escalation of the crisis between Sunni and Shia Muslims, which could ultimately lead to a war between Iran and Saudi Arabia (NG and oil prices to rise).
• An ISIS led attack on the gas pipeline infrastructure, which would have far greater implications than an attack on an oil tanker (NG prices in Europe to rise).
• A significant drop in U.S. shale gas production (NG prices in the U.S. to rise).
• Further development of recently established shale gas deposits in the Surrey Hills (NG prices in the U.K. to fall).
In addition to these ‘one off’ incidents, it is also possibly (actually quite likely) that European politicians will become increasingly creative in their desperate attempt to create renewed economic activity, as the demographic landslide sinks European GDP growth to new depths. One such initiative may be to improve competitiveness across the European Continent through lower electricity prices, and this would open the door for Iran to supply natural gas to the Europeans.
Obviously, none of these incidents may ever happen, but it could also be that they will all happen. As you can see from chart 6, neither European nor U.S. natural gas prices have, in any meaningful way, reacted to the sharp recent decline in oil prices, causing oil to be cheaper now than natural gas in Europe on a BOE basis.
Along the same lines, we also note that coal is now cheaper than natural gas in Europe after having been more expensive for a number of years. The global trend has been, and continues to be, in favour of using less polluting natural gas instead of oil or coal, but recent price swings may change all of that. This could make for an exceedingly interesting few years until markets ultimately find what we would call post-shale equilibrium prices on both oil and gas, and that may take quite a while yet.
As we know, commodity trading strategies thrive on volatility (unlike equity strategies most of which prefer low volatility), and we therefore think natural gas offers even better trading opportunities going forward than oil does, even if they both look quite interesting – provided the manager in question can go short as well as long.
Unless oil prices fall even further relative to natural gas prices, there is no reason to believe that oil will reverse its multi-year decline as a heating and power plant fuel. Natural gas burns much too cleanly for that to happen at the current price differential. As a result, unless the price differential widens substantially, we expect the low correlation between the two to continue, which will only increase the number of trading opportunities in the energy space.
Niels C. Jensen
5 August 2015 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2847825586795807, "perplexity": 2146.3602333242093}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600402130531.89/warc/CC-MAIN-20200930235415-20201001025415-00268.warc.gz"} |
http://math.stackexchange.com/questions/21990/proof-square-matrix-has-maximal-rank-if-and-only-if-it-is-invertible/21994 | # Proof - Square Matrix has maximal rank if and only if it is invertible
Could someone help me with the proof that a square matrix has maximal rank if and only if it is invertible?
Thanks to everybody
-
What is a quadratic matrix? – Qiaochu Yuan Feb 14 '11 at 12:43
@Qiaochu Yuan he obviously means square matrix – Listing Feb 14 '11 at 12:46
Yeah sorry for my english :) – markzzz Feb 14 '11 at 13:27
@user3123: I asked because it sounded like the OP could have been referring to a quadratic form rather than a matrix. – Qiaochu Yuan Feb 14 '11 at 14:01
please make your posts self-contained. Don't rely on the subject: put the entire information on the body. – Arturo Magidin Feb 14 '11 at 14:18
Suppose $A\in F^{n \times n}$. If A is invertible then there is a matrix B such that $AB=I$ so the standard basis $e_i$ (the columns of I) is in the image of A (these vectors are just the image Av where v are the columns of B) - this shows that $\dim (Im(A)) = n$.
On the other hand, if $\dim (Im (A))=n$ then for every i there is $v_i$ such that $A v_i = e_i$. Let B be the matrix with columns $v_i$ then $AB=I$ and A is invertible. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9085732698440552, "perplexity": 310.27001639082204}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398460263.61/warc/CC-MAIN-20151124205420-00129-ip-10-71-132-137.ec2.internal.warc.gz"} |
http://en.hd-a.cn/news/11.html | # Huaibei Huadian-Talking about the difference between passive isolator and active isolator
• Categories:News
• Author:
• Origin:
• Time of issue:2019-10-25 17:03
• Views:
(Summary description)It is generally believed that signal isolators that can work without external power supply are passive isolators; active isolators require a special external power supply, such as 24VDC or 220VAC. Advantages of passive isolators
# Huaibei Huadian-Talking about the difference between passive isolator and active isolator
(Summary description)It is generally believed that signal isolators that can work without external power supply are passive isolators; active isolators require a special external power supply, such as 24VDC or 220VAC.
• Categories:News
• Author:
• Origin:
• Time of issue:2019-10-25 17:03
• Views:
Information
It is generally believed that signal isolators that can work without external power supply are passive isolators; active isolators require a special external power supply, such as 24VDC or 220VAC.
1. Easy to use and outstanding economy, after all, it saves the power supply and power cord for powering the isolator;
2. Low power consumption and high reliability. The power consumption of passive isolators is very low. For example, the power consumption of TA2000 series passive isolators is only 0.07W / channel (typical value at 20mA output), which is an order of magnitude lower than similar active isolators. Lower power consumption means lower heat generation, thus ensuring the reliability of the isolator. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8880476951599121, "perplexity": 6851.188404788166}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610703514046.20/warc/CC-MAIN-20210117235743-20210118025743-00439.warc.gz"} |
https://socratic.org/questions/how-do-you-evaluate-6times8div4 | Algebra
Topics
# How do you evaluate 6times8div4?
Dec 20, 2016
$\left(6 \times 8\right) \div 4 = 48 \div 4 = 12$.
#### Explanation:
The standard convention is that multiplication and division have the same importance, so when deciding which to do first in a situation like this, we just evaluate left to right.
Going left to right, we'll first do the multiplication in this case. So we have $6 \times 8 \div 4 = \left(6 \times 8\right) \div 4 = 48 \div 4 = 12$.
##### Impact of this question
122 views around the world
You can reuse this answer | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 2, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9786780476570129, "perplexity": 1139.0030655466412}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514575513.97/warc/CC-MAIN-20190922114839-20190922140839-00119.warc.gz"} |
http://www.cs.columbia.edu/~rocco/papers/icalp09malicious.html | Learning Halfspaces with Malicious Noise.
A. Klivans and P. Long and R. Servedio.
Journal of Machine Learning Research 10(Dec), 2009, pp. 2715--2740.
Preliminary version in 36th International Conference on Automata, Languages and Programming (ICALP), 2009, pp. 609-621.
Abstract:
We give new algorithms for learning halfspaces in the challenging {\it malicious noise} model, where an adversary may corrupt both the labels and the underlying distribution of examples. Our algorithms can tolerate malicious noise rates exponentially larger than previous work in terms of the dependence on the dimension $n$, and succeed for the fairly broad class of all isotropic log-concave distributions.
We give poly$(n, 1/\eps)$-time algorithms for solving the following problems to accuracy $\epsilon$:
• Learning origin-centered halfspaces in $\R^n$ with respect to the uniform distribution on the unit ball with malicious noise rate $\eta = \Omega(\eps^2/\log(n/\eps)).$ (The best previous result was $\Omega(\eps/(n \log (n/\eps))^{1/4})$.)
• Learning origin-centered halfspaces with respect to any isotropic log-concave distribution on $\R^n$ with malicious noise rate $\eta = \Omega(\eps^{3}/\log(n/\epsilon)).$ This is the first efficient algorithm for learning under isotropic log-concave distributions in the presence of malicious noise.
• We also give a poly$(n,1/\eps)$-time algorithm for learning origin-centered halfspaces under any isotropic log-concave distribution on $\R^n$ in the presence of \emph{adversarial label noise} at rate $\eta = \Omega(\eps^{2}/\log(1/\eps))$. In the adversarial label noise setting (or agnostic model), labels can be noisy, but not example points themselves. Previous results could handle $\eta = \Omega(\eps)$ but had running time exponential in an unspecified function of $1/\eps$.
Our analysis crucially exploits both concentration and anti-concentration properties of isotropic log-concave distributions. Our algorithms combine an iterative outlier removal procedure using Principal Component Analysis together with smooth'' boosting.
pdf of conference version | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8988268375396729, "perplexity": 1093.0159532688085}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281353.56/warc/CC-MAIN-20170116095121-00149-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://www.nag.com/numeric/nl/nagdoc_26.2/nagdoc_cl26.2/html/g22/g22ybc.html | # NAG C Library Function Document
## nag_blgm_lm_describe_data (g22ybc)
Note: please be advised that this function is classed as ‘experimental’ and its interface may be developed further in the future. Please see Section 3.1.1 in How to Use the NAG Library and its Documentation for further information.
## 1Purpose
nag_blgm_lm_describe_data (g22ybc) describes a data matrix.
## 2Specification
#include #include
void nag_blgm_lm_describe_data (void **hddesc, Integer nobs, Integer nvar, const Integer levels[], Integer lvnames, const char *vnames[], NagError *fail)
## 3Description
Let $D$ denote a data matrix with $n$ observations on ${m}_{d}$ independent variables, denoted ${V}_{1},{V}_{2},\dots ,{V}_{{m}_{d}}$. The $j$th independent variable, ${V}_{j}$ can be classified as either binary, categorical, ordinal or continuous, where:
Binary
${V}_{j}$ can take the value $1$ or $0$.
Categorical
${V}_{j}$ can take one of ${L}_{j}$ distinct values or levels. Each level represents a discrete category but does not necessarily imply an ordering. The value used to represent each level is therefore arbitrary and, by convention and for convenience, is taken to be the integers from $1$ to ${L}_{j}$.
Ordinal
As with a categorical variable ${V}_{j}$ can take one of ${L}_{j}$ distinct values or levels. However, unlike a categorical variable, the levels of an ordinal variable imply an ordering and hence the value used to represent each level is not arbitrary. For example, ${V}_{j}=4$ implies a value that is twice as large as ${V}_{j}=2$.
Continuous
${V}_{j}$ can take any real value.
nag_blgm_lm_describe_data (g22ybc) returns a G22 handle containing a description of a data matrix, $D$. The data matrix makes no distinction between binary, ordinal or continuous variables.
A name can also be assigned to each variable. If names are not supplied then the default vector of names, $\left\{\text{'V1'},\text{'V2'},\dots \right\}$ is used.
None.
## 5Arguments
1: $\mathbf{hddesc}$void **Input/Output
On entry: must be set to NULL.
As an alternative an existing G22 handle may be supplied in which case this function will destroy the supplied G22 handle as if nag_blgm_handle_free (g22zac) had been called.
On exit: holds a G22 handle to the internal data structure containing a description of the data matrix, $D$. You must not change the G22 handle other than through the functions in Chapter g22.
2: $\mathbf{nobs}$IntegerInput
On entry: $n$, the number of observations in the data matrix, $D$.
Constraint: ${\mathbf{nobs}}\ge 0$.
3: $\mathbf{nvar}$IntegerInput
On entry: ${m}_{d}$, the number of variables in the data matrix, $D$.
Constraint: ${\mathbf{nvar}}\ge 0$.
4: $\mathbf{levels}\left[{\mathbf{nvar}}\right]$const IntegerInput
On entry: ${\mathbf{levels}}\left[\mathit{j}-1\right]$ contains the number of levels associated with the $\mathit{j}$th variable of the data matrix, for $\mathit{j}=1,2,\dots ,{\mathbf{nvar}}$.
If the $j$th variable is binary, ordinal or continuous, ${\mathbf{levels}}\left[j-1\right]$ should be set to $1$; otherwise ${\mathbf{levels}}\left[j-1\right]$ should be set to the number of levels associated with the $j$th variable and the corresponding column of the data matrix is assumed to take the value $1$ to ${\mathbf{levels}}\left[j-1\right]$.
Constraint: ${\mathbf{levels}}\left[\mathit{i}-1\right]\ge 1$, for $\mathit{i}=1,2,\dots ,{\mathbf{nvar}}$.
5: $\mathbf{lvnames}$IntegerInput
On entry: the number of variable names supplied in vnames.
Constraint: ${\mathbf{lvnames}}=0$, or ${\mathbf{nvar}}$.
6: $\mathbf{vnames}\left[{\mathbf{lvnames}}\right]$const char *Input
On entry: if ${\mathbf{lvnames}}\ne 0$, ${\mathbf{vnames}}\left[\mathit{j}-1\right]$ must contain the name of the $\mathit{j}$th variable, for $\mathit{j}=1,2,\dots ,{\mathbf{nvar}}$. If ${\mathbf{lvnames}}=0$, vnames is not referenced and may be NULL.
The names supplied in vnames should be at most $50$ characters long and be unique. If a name longer than $50$ characters is supplied it will be truncated.
Variable names must not contain any of the characters +.*-:^()@.
7: $\mathbf{fail}$NagError *Input/Output
The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).
## 6Error Indicators and Warnings
NE_ALLOC_FAIL
Dynamic memory allocation failed.
See Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.
NE_ARRAY_SIZE
On entry, ${\mathbf{lvnames}}=〈\mathit{\text{value}}〉$ and ${\mathbf{nvar}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{lvnames}}=0$, or ${\mathbf{nvar}}$.
On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.
NE_HANDLE
On entry, hddesc is not NULL or a recognised G22 handle.
NE_INT
On entry, ${\mathbf{nobs}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{nobs}}\ge 0$.
On entry, ${\mathbf{nvar}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{nvar}}\ge 0$.
NE_INT_ARRAY
On entry, $j=〈\mathit{\text{value}}〉$ and ${\mathbf{levels}}\left[j-1\right]=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{levels}}\left[\mathit{i}-1\right]\ge 1$.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 2.7.6 in How to Use the NAG Library and its Documentation for further information.
NE_INVALID_FORMAT
On entry, variable name $i$ contains one more invalid characters, $i=〈\mathit{\text{value}}〉$.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.
NE_NON_UNIQUE
On entry, variable names $i$ and $j$ are not unique (possibly due to truncation), $i=〈\mathit{\text{value}}〉$ and $j=〈\mathit{\text{value}}〉$.
Maximum variable name length is $50$.
On entry, variable names $i$ and $j$ are not unique, $i=〈\mathit{\text{value}}〉$ and $j=〈\mathit{\text{value}}〉$.
NW_TRUNCATED
At least one variable name was truncated to $50$ characters. Each truncated name is unique and will be used in all output.
Not applicable.
## 8Parallelism and Performance
nag_blgm_lm_describe_data (g22ybc) is not threaded in any implementation.
None.
## 10Example
This example performs a linear regression using nag_regsn_mult_linear (g02dac). The linear regression model is defined via a text string which is parsed using nag_blgm_lm_formula (g22yac). The corresponding design matrix associated with the model and the dataset described via a call to nag_blgm_lm_describe_data (g22ybc) is generated using nag_blgm_lm_design_matrix (g22ycc).
Verbose labels for the parameters of the model are constructed using information returned in vinfo by nag_blgm_lm_submodel (g22ydc).
See also the examples in nag_blgm_lm_formula (g22yac), nag_blgm_lm_design_matrix (g22ycc) and nag_blgm_lm_submodel (g22ydc).
### 10.1Program Text
Program Text (g22ybce.c)
### 10.2Program Data
Program Data (g22ybce.d)
### 10.3Program Results
Program Results (g22ybce.r)
## 11Optional Parameters
As well as the optional parameters common to all G22 handles described in nag_blgm_optset (g22zmc) and nag_blgm_optget (g22znc), a number of additional optional parameters can be specified for a G22 handle holding the description of a data matrix as returned by nag_blgm_lm_describe_data (g22ybc) in hddesc.
Each writeable optional parameter has an associated default value; to set any of them to a non-default value, use nag_blgm_optset (g22zmc). The value of an optional parameter can be queried using nag_blgm_optget (g22znc).
The remainder of this section can be skipped if you wish to use the default values for all optional parameters.
The following is a list of the optional parameters available. A full description of each optional parameter is provided in Section 11.1.
### 11.1Description of the Optional Parameters
For each option, we give a summary line, a description of the optional parameter and details of constraints.
The summary line contains:
• a parameter value, where the letters $a$, $i$ and $r$ denote options that take character, integer and real values respectively;
• the default value.
Keywords and character values are case and white space insensitive.
Number of Observations $i$
If queried, this optional parameter will return $n$, the number of observations in the data matrix.
Number of Variables $i$
If queried, this optional parameter will return ${m}_{d}$, the number of variables in the data matrix.
Storage Order $a$ Default $\text{}=\mathrm{OBSVAR}$
This optional parameter states how the data matrix, $D$, will be stored in its input array.
If ${\mathbf{Storage Order}}=\mathrm{OBSVAR}$, ${D}_{ij}$, the value for the $j$th variable of the $i$th observation of the data matrix is stored in ${\mathbf{dat}}\left[\left(j-1\right)×{\mathbf{pddat}}+i-1\right]$.
If ${\mathbf{Storage Order}}=\mathrm{VAROBS}$, ${D}_{ij}$, the value for the $j$th variable of the $i$th observation of the data matrix is stored in ${\mathbf{dat}}\left[\left(i-1\right)×{\mathbf{pddat}}+j-1\right]$.
Where dat is the input parameter of the same name in nag_blgm_lm_design_matrix (g22ycc).
Constraint: ${\mathbf{Storage Order}}=\mathrm{OBSVAR}$ or $\mathrm{VAROBS}$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 103, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8123012781143188, "perplexity": 1410.6113889322316}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046153966.52/warc/CC-MAIN-20210730091645-20210730121645-00185.warc.gz"} |
https://arxiv.org/abs/1911.02795 | astro-ph.GA
# Title:Estimating the molecular gas mass of low-redshift galaxies from a combination of mid-infrared luminosity and optical properties
Abstract: We present CO(J=1-0) and/or CO(J=2-1) spectroscopy for 31 galaxies selected from the ongoing MaNGA survey, obtained with multiple telescopes. This sample is combined with CO observations from the literature to study the correlation of the CO luminosities ($L_{\rm CO(1-0)}$) with the mid-infrared luminosities at 12 ($L_{12 \mu m}$) and 22 $\mu$m ($L_{\rm 22 \mu m}$), as well as the dependence of the residuals on a variety of galaxy properties. The correlation with $L_{\rm 12 \mu m}$ is tighter and more linear, but galaxies with relatively low stellar masses and blue colors fall significantly below the mean $L_{\rm CO(1-0)}-L_{\rm 12\mu m}$ relation. We propose a new estimator of the CO(1-0) luminosity (and thus the total molecular gas mass) that is a linear combination of three parameters: $L_{\rm 12 \mu m}$, $M_\ast$ and $g-r$. We show that, with a scatter of only 0.18 dex in log $(L_{\rm CO(1-0)})$, this estimator provides unbiased estimates for galaxies of different properties and types. An immediate application of this estimator to a compiled sample of galaxies with only CO(J=2-1) observations yields a distribution of the CO(J=2-1) to CO(J=1-0) luminosity ratios ($R21$) that agrees well with the distribution of real observations, in terms of both the median and the shape. Application of our estimator to the current MaNGA sample reveals a gas-poor population of galaxies that are predominantly early-type and show no correlation between molecular gas-to-stellar mass ratio and star formation rate, in contrast to gas-rich galaxies. We also provide alternative estimators with similar scatters, based on $r$ and/or $z$ band luminosities instead of $M_\ast$. These estimators serve as cheap and convenient $M_{\rm mol}$ proxies to be potentially applied to large samples of galaxies, thus allowing statistical studies of gas-related processes of galaxies.
Comments: 24 pages, 12 figures, accepted for publication in ApJ Subjects: Astrophysics of Galaxies (astro-ph.GA) Cite as: arXiv:1911.02795 [astro-ph.GA] (or arXiv:1911.02795v2 [astro-ph.GA] for this version)
## Submission history
From: Yang Gao [view email]
[v1] Thu, 7 Nov 2019 08:17:55 UTC (2,114 KB)
[v2] Mon, 11 Nov 2019 02:39:49 UTC (2,114 KB) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.884438157081604, "perplexity": 2419.1815078914665}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496670006.89/warc/CC-MAIN-20191119042928-20191119070928-00557.warc.gz"} |
https://math.stackexchange.com/questions/3145476/how-to-calculate-textcov-haty-ij-haty-kj-if-y-ij-mu-a-i | # How to calculate $\text{cov}(\hat{Y}_{ij}, \hat{Y}_{kj})$ if $Y_{ij} = \mu + a_i + b_j + e_{ij}$?
Let's assume we have the model following Two-Factor model without replications : $$Y_{ij} = \mu + a_i + b_j + e_{ij}, \; i=1,\dots,p \; \text{and} \; j=1,\dots, q$$ I am interested in calculating the covariance : $$\text{cov}(\hat{Y}_{ij}, \hat{Y}_{kj}), \quad i \neq k$$ I know that the estimators can be written as : $$\hat{Y}_{ij} = \overline{Y}_{i\cdot} + \overline{Y}_{\cdot j} - \overline{Y}_{\cdot \cdot} \quad\text{and}\quad \hat{Y}_{ik} = \overline{Y}_{i\cdot} + \overline{Y}_{\cdot k} - \overline{Y}_{\cdot \cdot}$$ That would make the covariance expression : $$\text{cov}(\hat{Y}_{ij}, \hat{Y}_{kj}) = \text{cov}(\overline{Y}_{i\cdot} + \overline{Y}_{\cdot j} - \overline{Y}_{\cdot \cdot}, \overline{Y}_{i\cdot} + \overline{Y}_{\cdot k} - \overline{Y}_{\cdot \cdot})$$ I know that I can break this covariance up in combinations, but I am having trouble calculating each one. Except from the term $$\text{cov}(\overline{Y}_{\cdot \cdot}, \overline{Y}_{\cdot \cdot}) = \sigma^2/pq$$, I seem to struggle to find the rest of them. Any tips on the calculations ? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 5, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8931541442871094, "perplexity": 152.27388591769082}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-18/segments/1555578529606.64/warc/CC-MAIN-20190420100901-20190420122901-00116.warc.gz"} |
https://scoop.eduncle.com/65-a-nucleus-has-a-mass-number-216-its-radius-is-a-0-78-fermi-b-0-078-fermi-c-78-fermi-d-7-8-fermi | CSIR NET Follow
April 10, 2021 9:48 pm 30 pts
65. A nucleus has a mass number 216. Its radius is (A) 0.78 fermi (B) 0.078 fermi (C) 78 fermi (D) 7.8 fermi
• 1 Likes
• Shares
• Dinesh vishwakarma
d) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9361428022384644, "perplexity": 23085.028614621082}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243988858.72/warc/CC-MAIN-20210508091446-20210508121446-00563.warc.gz"} |
https://gaugehow.com/sine-bar/ | # Sine Bar
### Introduction
Sine bar is a precision angle measuring instrument along with slip gauges. The name suggests that Sine bar work on sine principle. Slip gauge used to build up the height of sine bar.
The required angle is obtained when the difference in height between the two rollers is equal to the Sine of the angle multiplied by the distance between the centers of the rollers.
### How to measure with Sine bar ?
Sine Bar is an indirect method of measurement. Sine Bar is working on Sine principle that is the ratio of length between two roller and height differences.
In the above picture, we are taking a very simple case. Height differences angle H1-H2 is zero, so, after calculation, our result is 180 degree.
### Pros & Corns of sine bar
Some Advantages of sine bar are
1. It is precise and accurate
2. Its design is quite simple
3. Availability of Sine bar is high | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9813063740730286, "perplexity": 1564.2538726832252}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655891654.18/warc/CC-MAIN-20200707044954-20200707074954-00559.warc.gz"} |
https://www.gamasutra.com/blogs/CalebCompton/20190312/338384/Game_Design_in_Real_Life_Playing_With_Incentives.php | Gamasutra is part of the Informa Tech Division of Informa PLC
This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.
October 15, 2019
Press Releases
October 15, 2019
Games Press
If you enjoy reading this site, you might also want to check out these UBM Tech sites:
by Caleb Compton on 03/12/19 10:34:00 am
The following blog post, unless otherwise noted, was written by a member of Gamasutra’s community.
The thoughts and opinions expressed are those of the writer and not Gamasutra or its parent company.
The following is a reproduction, and has been modified for this site. The original article, and many more, can be found at RemptonGames.com
Why is education important? Aside from the inherent joy of learning and the desire to constantly improve yourself and enrich your life, the answer most people would probably give is that you need education to get a job. But why do you need a job? Why, to earn money of course!
Why do you need money? To buy things, such as food, clothes, shelter and entertainment. Of course, you don’t need to work to get those things. You could just steal them! Stealing food from the grocery stores, clothes from clothing shops, etc. But most people don’t live that way. Why not?
There are two main reasons. The first is the fear of punishment – if you just stole everything you needed, chances are you will eventually get caught and punished with jail-time or fines at the very least. The second reason is an understanding that society would not work if everybody behaved this way, and not wanting to contribute to the weakening of society.
These are all examples of incentives. Whether it is the promise of education helping you get a job or the fear of getting arrested preventing us from breaking the law, most things that people do can be understood in terms of the incentives that drive the behavior.
Why am I talking about this? What does it have to do with game design? Why am I asking you so many questions? I am simply trying to illustrate a point – nearly everything we do (or don’t do) is caused by one thing – incentives. Incentives are one of the primary forces in the world that guide behavior, and can be a very powerful tool in game design.
# Inventive Incentives
Simply put, an incentive is anything that is designed to motivate or encourage somebody to behave a certain way. Incentives can be divided into a number of subcategories, and the type of incentive used can make a big difference in how people react. The two main areas that incentives differ are Positive vs Negative incentives and Intrinsic vs Extrinsic incentives.
First, lets look at positive and negative incentives. Put simply, a positive incentive is a reward for performing some action, while a negative incentive is a cost or punishment for performing an action. In general, if you want somebody to do something more often you should use a positive incentive to reward them for that action. If you give your dog a treat after you tell them to sit, they are more likely to obey that command in the future.
Similarly, if you want somebody to stop doing something (or do it less frequently) you would attach a negative incentive to that action. For example, if you want your co-worker to stop chewing with his mouth open you could squirt him in the face with a water gun every time you see him do that, which would incentivize him to stop.
For extra incentive-y goodness you can always combine positive and negative incentives to form a “carrot and stick”. This doubles down on encouraging a particular behavior by not only rewarding that behavior when it is performed, but also providing costs or punishment when it is not. This combination can be very effective, and should only be used when extreme motivation is necessary.
An example of positive and negative incentives in the modern world can be found in the tax system. Without getting too political, taxes are often used as an incentive by governments to encourage or discourage particular behaviors. For example, if a government wants to discourage cigarette smoking they may add a negative incentive to that behavior by raising taxes.
In the same vein, governments can encourage certain behaviors, such as charitable giving, by associating a tax break with those behaviors.
However, as you may already be able to tell from my use of this example, incentives are not always used thoughtfully. Continuing with the tax example, while taxes are occasionally used for their value as incentives, they are often simply seen as a way to raise money without regard to the effect that a particular new tax might have on behavior. This is a mistake, and I believe more thought should be put into how new taxes or tax breaks could affect the behavior of the public.
The next way to distinguish incentives is between intrinsic and extrinsic incentives. Basically, this is a distinction based on the source of the incentive. An intrinsic incentive has an internal source, whereas an extrinsic incentive comes from some outside source.
Intrinsic incentives are generally not tangible – they are positive or negative feelings and emotions that can drive behavior. In a game the most obvious example of an intrinsic incentive is fun – you perform actions in the game because you enjoy them.
Extrinsic incentives, on the other hand, tend to be more tangible. Things like money, items and services can be provided as a form of extrinsic incentive. In a game, an example of an extrinsic incentive would be providing the player with Victory Points, currency, or anything else that could improve their chances of winning.
# The Most Important Rules of Incentives
• Rule #1 – whenever there is an incentive to do something, some subset of the population will try to take advantage of it
This is something that must be planned for, otherwise you will be caught off guard. A great example of this comes from a promotion by PepsiCo known as Pepsi Stuff from the mid 1990s. Under this promotion people could earn Pepsi Points by buying various Pepsi products, and these points could then be traded in for various prizes. While most of the prizes were relatively normal items such as t-shirts and sunglasses, one commercial showed a Harrier Jet as a prize for 7,000,000 Pepsi Points.
Including the jet as a prize was, of course, intended as a joke, and Pepsi thought that there was no chance of anybody actually collecting 7 million points. However, they had forgotten the first rule of incentive systems. It turned out that you could purchase 7 million points for a mere $700,000 dollars (far below the manufacturing cost of around$25,000,000). This meant that anybody who was actually able to redeem this prize would make a huge profit so, unsurprisingly, somebody decided to go for it.
That person turned out to be a 21 year old business student named John Leonard. Leonard was able to raise the \$700,000 from a number of wealthy investors, bought the points, and mailed the off to PepsiCo. Unfortunately, Pepsi refused to give Leonard his prize, which led to a legal battle which eventually ruled in Pepsi’s favor. Sadly, Leonard never got the jet that he rightfully deserved, but through this process everybody learned an important lesson. Pepsi continued to air the commercial, but changed the 7 million points to 700 million, which now meant that the cost of buying the points was more than the cost of the jet itself.
• Rule #2 – People will do things they don’t want to do if the incentive is high enough
Put another way, a strong enough extrinsic incentive can and will overcome intrinsic incentives. This may seem obvious, and in fact one of the primary uses for incentives is getting people to do things that they don’t want to do. However, the important thing to keep in mind with this rule is that it doesn’t just apply to times when you are trying to get people to do things. Incentives can and will affect behavior even if that is not the goal, and therefore it is important think about what behaviors you may unwittingly be encouraging in your game.
For another real-life example, lets look at a promotion started by Hoover vacuums that coincidentally also took place in the early 90’s. Hoover’s marketing department made an offer to provide two free airline tickets with the purchase of any vacuum worth over 100 pounds. They believed that this would encourage people to buy the more expensive models, since it would seem like a more reasonable purchase with the tickets.
Unfortunately, that’s not how incentives work, as they soon learned. Before long hundreds of thousands of people had ordered cheap vacuums that they didn’t want, for the sole purpose of getting the much more valuable free tickets. This led to huge losses for the company – while they sold around 30 million pounds worth of vacuums, they ended up spending more than 50 million pounds on airline tickets.
The fundamental mistake here is that Hoover believed that adding this additional incentive would NOT fundamentally change consumer behavior. They believed people would only buy vacuums if they needed them, but would be more willing to buy the more expensive models and less likely to go with a competitor.
The flaw in this logic is that changing behavior is literally the entire point of creating an incentive in the first place. You cannot add a new incentive and expect behavior not to change, you can only attempt to anticipate what kind of change will occur.
# Incentive Tension
One interesting aspect of incentives is the tension that can occur when multiple incentives conflict with one another. In fact, this is the core of strategy in games. At any given time you have several options, and many of them will move you further towards your goal. However, in order to make one choice you have to miss out on others, and it is up to the player to decide what is the most valuable to them.
Therefore, when designing games it can sometimes be necessary to purposefully add conflicting incentives to add additional depth of strategy to the game. However, it is important not to overdo it, and finding the right balance for your particular game can be quite a difficult task.
To see why, lets consider a game that has no conflicting incentives. Generally this means that your game will only have a single goal, and a single path to achieve that goal. These games tend to be quite simple, and are played more for fun than strategy.
An example of this is Apples to Apples. The only thing the game encourages you to do is to pick the card that is most likely to be chosen. There is no tension or conflict among the incentives, which leads to a very simple and straightforward game without a lot of strategic depth.
On the other extreme you have “point salad games” such as Tokaido, where there is such constant tension between different incentives that it becomes difficult to even make an informed choice about what to do. Pretty much any action you take will give you victory points, and when you are being pulled in all directions at once it is the same as having no direction at all.
Most games are going to find themselves somewhere in the middle of these two extremes. You want enough tension to force your player to make meaningful decisions, but not too much tension that makes it impossible for them to actually choose.
However, there is one area that you absolutely want to avoid designing tension, and that is between what your player WANTS to do and what they NEED to do to win. Basically, your players are going to be drawn to the most fun parts of your game – this is an intrinsic incentive. However, if those fun parts of the game are not necessary to win (or even counterproductive) this can lead to a very dangerous type of tension.
In this situation your player only has two choices, neither of which are very desirable. On the one hand they can take the path that leads to victory, but if this path isn’t fun it can lead to disappointment. On the other hand they can take the fun path, but this too can lead to disappointment if they never win.
This sort of tension is not good for your game, and if you encounter it in your game it probably means you need to adjust some things so that the fun path is also the path that leads to victory.
# Until Next Time!
That is all I have for this week. If you enjoyed this article, check out the rest of the blog and subscribe on Twitter, Youtube, or here on WordPress so you will always know when I post a new article. If you didn’t, let me know what I can do better in the comments down below. And join me next week for my second video article, which you can help choose on Twitter!
### Related Jobs
Deep Silver Volition — Champaign, Illinois, United States
[10.14.19]
Animator
University of Utah — Salt Lake City, Utah, United States
[10.14.19]
Assistant Professor (Lecturer)
HB Studios — Lunenburg/Halifax, Nova Scotia, Canada
[10.14.19]
Experienced Software Engineer
Take Two Interactive Software Inc. — Westwood , Massachusetts, United States
[10.11.19]
Producer | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.1653580367565155, "perplexity": 958.6022092011062}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986659097.10/warc/CC-MAIN-20191015131723-20191015155223-00413.warc.gz"} |
https://www.gamedev.net/articles/programming/general-and-gameplay-programming/gba-development-from-the-ground-up-volume-2-r1780/ | • # GBA Development From the Ground Up, Volume 2
General and Gameplay Programming
This article will describe how to change the screen mode for the GBA and how to draw images in the bitmap modes 3, 4, and 5.
Let's begin.
[size="5"]Getting the Compiler Working
I hope you downloaded ALL the files needed for your operating system from the DevKitAdv site, as they will all be indispensable (except for maybe the C++ additions, but I like C++ and will probably use it in this article). Unzip all the files to the root directory, and you should have a new directory called DevKitAdv. Congratulations, you just installed DevKitAdv with everything you need.
Now open your friendly Notepad and type in some code. Save this code as anything you want with a .c extension (I'll use test.c for this example).
#include int main() { return 0; }
Yes, I know it doesn't do anything. This is just an example to get the compiler working. Also, make sure you hit return after the final brace or else your compiler will whine at you (for some reason there has to be a new line at the end of every file).
Now open up your text editor again and type in the following:
gcc -o test.elf test.c
objcopy -O binary test.elf test.bin[/color][/font][/bquote]
Save this file as Make.bat. Note that some of the information in the file might have to change depending on the name of your file and what drive DevKitAdvance is installed on.
Now double click on Make.bat. Wait for the program to end. Congratulations, you just wrote your first program. What the make file does is call gcc to create test.elf from test.c, then it calls objcopy to create test.bin from test.elf. You might want to read that a few times if you didn't get it. However, regardless of if you understand that or not, those are the only three lines you'll need to put in a make file to get your program to compile (although those lines may have to vary depending on how many source files you use and the names of these files). For example, if you were using two source files named test.c and input.c, you'd simply change the second line to:
[bquote][font="Courier New"][color="#000080"]gcc -o test.elf test.c input.c[/color][/font][/bquote]
I hope you understand, because things only get more complicated from here. :-)
Now that we know how to compile a simple program, let's move on.
[size="5"]Using What You Create
When you compile your program, two files should be created - a .elf and a .bin. You want to use the .bin. Simply run this .bin using your respective emulator to view your creations.
If you have a linker and a cart, use the linker (instructions are included and more info can be found at www.visoly.com) to write the .bin to the cart. Push the cart in your GBA, turn the GBA on, and viola! Your creations are running on hardware!
[size="5"]Screen Modes, Among Other Things
As I said earlier, the GBA has 6 different screen modes to choose between. From the moment I said that, I bet you were wondering, "How do I change between them?" The answer lies in the REG_DISPCNT that is defined in gba.h.
However, you may be wondering where this elusive "gba.h" is. Well, the answer is quite simple: you don't have it. It's rather long, and its contents are going to be divulged throughout the course of all these articles, so I'm going to do what I don't like doing and just throw the entire thing at you. Get it in the attached resource file.
This wonderful file has pointers to sprite data, input data, screen data, and just about every piece of data you're ever going to mess with. You'll need it in every GBA project you create.
REG_DISPCNT is a 16 bit register at memory address 0x4000000. Each bit within this register controls something of the GBA. Here's a description:
Bits 0-2: Control the screen mode and can be any value between 0 and 5 Bit 3: Automatically set on a GBA if a GB or GBC cartridge is put in (ignore it). Bit 4: Used for double buffering in screen modes 4 and 5. Bit 5: Allows OAM to be set during horizontal blank (I'll explain further when we get to sprites). Bit 6: Determines if we are using 1D or 2D mapping for sprites. Again, I'll give more information when that bridge must be crossed. Bit 7: Puts the screen into a forced blank. Bits 8-11: Enable backgrounds 0-4 (more on this when we get to tile maps). Bit 12: Enables hardware rendered sprites. Bits 13-15: Enables window displays (I don't have much info on these).
Handy for one 16 bit number, 'eh? Personally I probably would have rather remembered a bunch of different variable names than one variable name and the specifics on every bit in it, but oh well. Now that we know what each bit stands for, we need a way to change the values. This can be done by bit masking (the | operator) a series of numbers into the register. But who wants to remember a bunch of numbers when we can create a header file and use variable names instead? Let's do that.
//screenmodes.h #ifndef __SCREENMODES__ #define __SCREENMODES__ #define SCREENMODE0 0x0 //Enable screen mode 0 #define SCREENMODE1 0x1 //Enable screen mode 1 #define SCREENMODE2 0x2 //Enable screen mode 2 #define SCREENMODE3 0x3 //Enable screen mode 3 #define SCREENMODE4 0x4 //Enable screen mode 4 #define SCREENMODE5 0x5 //Enable screen mode 5 #define BACKBUFFER 0x10 //Determine backbuffer #define HBLANKOAM 0x20 //Update OAM during HBlank? #define OBJMAP2D 0x0 //2D object (sprite) mapping #define OBJMAP1D 0x40 //1D object(sprite) mapping #define FORCEBLANK 0x80 //Force a blank #define BG0ENABLE 0x100 //Enable background 0 #define BG1ENABLE 0x200 //Enable background 1 #define BG2ENABLE 0x400 //Enable background 2 #define BG3ENABLE 0x800 //Enable background 3 #define OBJENABLE 0x1000 //Enable sprites #define WIN1ENABLE 0x2000 //Enable window 1 #define WIN2ENABLE 0x4000 //Enable window 2 #define WINOBJENABLE 0x8000 //Enable object window #define SetMode(mode) (REG_DISPCNT = mode) #endif
There we have our header file. Now if we wanted to set the screen mode to screen mode 3 and support sprites, we'd simply include this file in our main source file and say:
SetMode( SCREENMODE3 | OBJENABLE );
Naturally, this header file is terribly important, and I recommend including it in all your projects.
[size="5"]Drawing to the Screen
Drawing to the screen is remarkably easy now that we have the screen mode set up. The video memory, located at 0x6000000, is simply a linear array of numbers indicating color. Thus, all we have to do to put a pixel on the screen is write to the correct offset off this area of memory. What's more, we already have a #define in our gba.h telling us where the video memory is located (called VideoBuffer). One minor thing you should take note of is that in the 16bit color modes, colors are stored in the blue, green, red color format, so you'll want a macro to take RGB values and convert them to the appropriate 16bit number. Furthermore, we only actually use 15 bytes. Also, when you set the screen mode to a pixel mode, Background 2 must be turned on because that's where all the pixels are drawn.
Here's an example:
#include "gba.h" #include "screenmodes.h" u16* theVideoBuffer = (u16*)VideoBuffer; #define RGB(r,g,b) (r+(g<<5)+(b<<10)) //Macro to build a color from its parts int main() { SetMode( SCREENMODE3 | BG2ENABLE ); //Set screen mode int x = 10, y = 10; //Pixel location theVideoBuffer[ x + y * 240 ] = RGB( 31, 31, 31 ); //Plot our pixel return 0; }
All this example does is plot a white pixel at screen position 10,10. Very easy.
Mode 5 is nearly identical. Simply replace the SCREENMODE3 with SCREENMODE5 in the SetMode macro, and instead of theVideoBuffer[ x + y * 240 ] say theVideoBuffer[ x + y * 160 ] because the screen is only 160 pixels in width. If you want to use the second buffer for Mode 5, read on, because I'll describe double buffering for Mode 4 in just a bit. Double buffering is identical in both screen modes - the method of drawing to the buffer is slightly changed, though.
Mode 4 is slightly more complex since it is only an 8bit color mode and it utilizes the backbuffer. Naturally, change the SCREENMODE3 to SCREENMODE4 in SetMode (this should be self-explanatory, and I'm not going to note the change anymore). However, now we need a few more things.
Before we do any drawing with Mode 4, we need a palette. The palette is stored at 0x5000000 and is simply 256 16bit numbers representing all the possible colors. The memory is pointed to in gba.h, and the pointer is called BGPaletteMem.
u16* theScreenPalette = (u16*)BGPaletteMem;
To put a color in the palette we simply say
theScreenPalette[ position ] = RGB( red, green, blue );
Now mind you, I don't recommend you hard code all the palette entries. There are programs on the internet to get the palette from files and put it in an easy to use format. Furthermore, the color at position 0 should always be black (0,0,0) - this will be your transparent color.
Now we need to point to the area of memory where the backbuffer is stored (0x600A000). Guess what - this pointer is already in our gba.h. Behold, BackBuffer!
u16* theBackBuffer = (u16*)BackBuffer;
Now always write to the backbuffer instead of the video buffer. Then you can call the Flip function to switch between the two. Basically, the Flip function changes which part of video memory is being viewed and changes the pointers around. Thus, you will always be viewing the buffer in the front and always be drawing to the buffer in the back. Here's the function:
void Flip() { if (REG_DISPCNT & BACKBUFFER) { REG_DISPCNT &= ~BACKBUFFER; theVideoBuffer = theBackBuffer; } else { REG_DISPCNT |= BACKBUFFER; theVideoBuffer = theBackBuffer; } }
However, you only want to call this function one time in your main loop. That time is during the vertical blank. The vertical blank is a brief period when the GBA hardware isn't drawing anything. If you draw any other time, there is a possibility that images will be choppy and distorted because you're writing data at the same time the drawing is taking place. This effect is known as "Shearing."
Luckily, the function to wait for the vertical blank is very simple. All it does is get a pointer to the area that stores the position of the vertical drawing. Once this counter reaches 160 (the y resolution, and thus the end of the screen), the vertical blank is occurring. Nothing should happen until that vertical blank happens, so we trap ourselves in a loop. Note that in Mode 5, the y resolution is only 128, so you'll want to change your wait accordingly.
void WaitForVblank() { #define ScanlineCounter *(volatile u16*)0x4000006; while(ScanlineCounter<160){} }
Take that all in? Good, because there's another pitfall to Mode 4. Although it is an 8bit mode, the GBA hardware was set up so you can only write 16 bits at a time. This basically means that you either have to do a little extra processing to take into account 2 adjacent pixels (which is slow and unrecommended) or draw two pixels of the same color at a time (which cuts your resolution and is also unrecommended).
Here's a "short" example of drawing a pixel to help you take all this in, because it's a lot of information all at once.
#include "gba.h" #include "screenmodes.h" u16* theVideoBuffer = (u16*)VideoBuffer; u16* theBackBuffer = (u16*)BackBuffer; u16* theScreenPalette = (u16*)BGPaletteMem; #define RGB(r,g,b) (r+(g<<5)+(b<<10)) //Macro to build a color from its parts void WaitForVblank() { #define ScanlineCounter *(volatile u16*)0x4000006 while(ScanlineCounter<160){} } void Flip() { if (REG_DISPCNT & BACKBUFFER) { REG_DISPCNT &= ~BACKBUFFER; theVideoBuffer = theBackBuffer; } else { REG_DISPCNT |= BACKBUFFER; theVideoBuffer = theBackBuffer; } } int main() { SetMode( SCREENMODE4 | BG2ENABLE ); //Set screen mode int x = 0, y = 0; //Coordinate for our left pixel theScreenPalette[1] = RGB( 31, 31, 31); //Add white to the palette theScreenPalette[2] = RGB(31,0,0); //Add red to the palette u16 twoColors = (( 1 << 8 ) + 2); //Left pixel = 0, right pixel = 1 theBackBuffer[x + y * 240 ] = twoColors; //Write the two colours WaitForVblank(); //Wait for a vertical blank Flip(); //Flip the buffers return 0; }
There you have it. What does that all build up to?
I don't recommend you use Mode 4 unless you really have to or you plan everything out meticulously, but I thought you should have the information in case you needed it.
Drawing an image made in another program is remarkably easy - I've practically given you all the information already.
First, get an image converter/creation program. www.gbadev.org is a great place to get one. With an image converter, take the .bmp or .gif or .pcx or whatever (depending on what the program uses), and convert the image to a standard C .h file. If your image uses a palette, this .h file should have both palette information and image information stored in separate arrays.
Now, all drawing the image consists of is reading from the arrays. Read from the palette array (if there is any) and put the data into the palette memory. To draw the image, simply run a loop that goes through your array and puts the pixels defined in the array at the desired location.
Naturally, these steps will be slightly different depending on what program you're using. However, being the nice guy that I am, I'm going to provide you with a quick example.
The image: A 240*160, 8 bit image named gbatest.bmp
The command line: gfx2gba gbatest.bmp gbatest.h -8 -w 240
The code:
#include "gba.h" #include "screenmodes.h" #include "gbatest.h" u16* theVideoBuffer = (u16*)VideoBuffer; u16* theScreenPalette = (u16*)BGPaletteMem; #define RGB(r,g,b) (r+(g<<5)+(b<<10)) //Macro to build a color from its parts int main() { SetMode(SCREENMODE4|BG2ENABLE); //Copy the palette u16 i; for ( i = 0; i < 256; i++ ) theScreenPalette[ i ] = gbatestPalette[ i ]; //Cast a 16 bit pointer to our data so we can read/write 16 bits at a time easily u16* tempData = (u16*)gbatest; //Write the data //Note we're using 120 instead of 240 because we're writing 16 bits //(2 colors) at a time. u16 x, y; for ( x = 0; x < 120; x++ ) for ( y = 0; y < 160; y++ ) theVideoBuffer[ y * 120 + x ] = tempData[ y * 120 + x ]; return 0; }
And that's all! I didn't use the backbuffer, because I was just trying to make a point. I used Mode 4 so that I could press the fact that you MUST write 16 bits at a time. If you were using Mode 3/16 bit color, you wouldn't need the tempData pointer. You would also change the 120s back to 240s.
In fact, that's the end of this article. By now, you should have bitmapped modes mastered, or at least you should have a relatively firm grasp on them.
[size="5"]Next Article
In the next article, I'm going to give you information on a rather easy topic - input. If you're lucky, I might even make a game demo to show off.
[size="5"]Acknowledgements
I would like to thank dovoto, as his tutorials have been my biggest source of information on GBA development since I started. Check out his site at www.thepernproject.com. I'd also like to thank the guys in #gamedev and #gbadev on EFNet in IRC for all their help, and all the help they'll be giving me as I write these articles. Furthermore, I would like to thank www.gbadev.org/. The site is a great resource, and it is definitely worth your time.
If you have any questions or comments, you can always e-mail me at [email="[email protected]"][email protected][/email] or [email="[email protected]"][email protected][/email]. I can't promise I'll answer your questions, like your comments, or listen to your suggestions, but I'll at least read the e-mail (as long as it doesn't look like spam).
Report Article
## User Feedback
There are no comments to display.
## Create an account
Register a new account
• 14
• 9
• 23
• 9
• 32 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3517548143863678, "perplexity": 2900.9843810893453}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267159820.67/warc/CC-MAIN-20180923212605-20180923233005-00473.warc.gz"} |
https://www.on-time.hu/cn2tvd2/what-is-the-second-fundamental-theorem-of-calculus-bd3689 | # what is the second fundamental theorem of calculus
in Egyéb - 2020-12-30
In the upcoming lessons, we’ll work through a few famous calculus rules and applications. d x dt Example: Evaluate . A slight change in perspective allows us to gain even more insight into the meaning of the definite integral. Using the Second Fundamental Theorem of Calculus, we have . As mentioned earlier, the Fundamental Theorem of Calculus is an extremely powerful theorem that establishes the relationship between differentiation and integration, and gives us a way to evaluate definite integrals without using Riemann sums or calculating areas. In this article, let us discuss the first, and the second fundamental theorem of calculus, and evaluating the definite integral using the theorems in detail. This video provides an example of how to apply the second fundamental theorem of calculus to determine the derivative of an integral. Consider the function f(t) = t. For any value of x > 0, I can calculate the de nite integral Z x 0 f(t)dt = Z x 0 tdt: by nding the area under the curve: 18 16 14 12 10 8 6 4 2 Ð 2 Ð 4 Ð 6 Ð 8 Ð 10 Ð 12 Ð 14 Ð 16 Ð 18 It states that if f (x) is continuous over an interval [a, b] and the function F (x) is defined by F (x) = ∫ a x f (t)dt, then F’ (x) = f (x) over [a, b]. However, this, in my view is different from the proof given in Thomas'-calculus (or just any standard textbook), since it does not make use of the Mean value theorem anywhere. Example. identify, and interpret, ∫10v(t)dt. The second fundamental theorem of calculus is basically a restatement of the first fundamental theorem. All that is needed to be able to use this theorem is any antiderivative of the integrand. Define . Fundamental Theorem of Calculus Part 1: Integrals and Antiderivatives. The first fundamental theorem of calculus states that, if f is continuous on the closed interval [a,b] and F is the indefinite integral of f on [a,b], then int_a^bf(x)dx=F(b)-F(a). The second part of the theorem (FTC 2) gives us an easy way to compute definite integrals. Fundamental Theorem Of Calculus: The original function lets us skip adding up a gajillion small pieces. dx 1 t2 This question challenges your ability to understand what the question means. Applying the fundamental theorem of calculus tells us $\int_{F(a)}^{F(b)} \mathrm{d}u = F(b) - F(a)$ Your argument has the further complication of working in terms of differentials — which, while a great thing, at this point in your education you probably don't really know what those are even though you've seen them used enough to be able to mimic the arguments people make with them. We use the chain rule so that we can apply the second fundamental theorem of calculus. As we learned in indefinite integrals , a primitive of a a function f(x) is another function whose derivative is f(x). When we do this, F(x) is the anti-derivative of f(x), and f(x) is the derivative of F(x). Let Fbe an antiderivative of f, as in the statement of the theorem. The Second Fundamental Theorem of Calculus shows that integration can be reversed by differentiation. Solution. Pick a function f which is continuous on the interval [0, 1], and use the Second Fundamental Theorem of Calculus to evaluate f(x) dx two times, by using two different antiderivatives. The second fundamental theorem of calculus states that if f(x) is continuous in the interval [a, b] and F is the indefinite integral of f(x) on [a, b], then F'(x) = f(x). It has two main branches – differential calculus and integral calculus. It has gone up to its peak and is falling down, but the difference between its height at and is ft. The second part states that the indefinite integral of a function can be used to calculate any definite integral, \int_a^b f(x)\,dx = F(b) - F(a). The Second Part of the Fundamental Theorem of Calculus The second part tells us how we can calculate a definite integral. Moreover, with careful observation, we can even see that is concave up when is positive and that is concave down when is negative. Find (a) F(π) (b) (c) To find the value F(x), we integrate the sine function from 0 to x. The Fundamental Theorem of Calculus is a theorem that connects the two branches of calculus, differential and integral, into a single framework. F0(x) = f(x) on I. Introduction. That's fundamental theorem of calculus. Area Function It can be used to find definite integrals without using limits of sums . (1) This result, while taught early in elementary calculus courses, is actually a very deep result connecting the purely algebraic indefinite integral and the purely analytic (or geometric) definite integral. Using The Second Fundamental Theorem of Calculus This is the quiz question which everybody gets wrong until they practice it. This sketch investigates the integral definition of a function that is used in the 2nd Fundamental Theorem of Calculus as a form of an anti-derivativ… Finding derivative with fundamental theorem of calculus: chain rule Our mission is to provide a free, world-class education to anyone, anywhere. The second figure shows that in a different way: at any x-value, the C f line is 30 units below the A f line. (a) To find F(π), we integrate sine from 0 to π:. It looks very complicated, but … The Second Fundamental Theorem of Calculus is our shortcut formula for calculating definite integrals. Fix a point a in I and de ne a function F on I by F(x) = Z x a f(t)dt: Then F is an antiderivative of f on the interval I, i.e. Let f be a continuous function de ned on an interval I. The second fundamental theorem can be proved using Riemann sums. To assist with the determination of antiderivatives, the Antiderivative [ Maplet Viewer ][ Maplenet ] and Integration [ Maplet Viewer ][ Maplenet ] maplets are still available. - The variable is an upper limit (not a lower limit) and the lower limit is still a constant. PROOF OF FTC - PART II This is much easier than Part I! Find the derivative of . The fundamental theorem of calculus has two separate parts. The Fundamental theorem of calculus links these two branches. This means we're accumulating the weighted area between sin t and the t-axis from 0 to π:. Second Fundamental Theorem of Calculus We have seen the Fundamental Theorem of Calculus , which states: If f is continuous on the interval [ a , b ], then In other words, the definite integral of a derivative gets us back to the original function. The First Fundamental Theorem of Calculus shows that integration can be undone by differentiation. Specifically, for a function f that is continuous over an interval I containing the x-value a, the theorem allows us to create a new function, F(x), by integrating f from a to x. The Fundamental Theorem of Calculus relates three very different concepts: The definite integral $\int_a^b f(x)\, dx$ is the limit of a sum. So we evaluate that at 0 to get big F double prime at 0. Second Fundamental Theorem of Calculus. Let f(x) = sin x and a = 0. Thus if a ball is thrown straight up into the air with velocity the height of the ball, second later, will be feet above the initial height. As antiderivatives and derivatives are opposites are each other, if you derive the antiderivative of the function, you get the original function. Calculus is the mathematical study of continuous change. There are several key things to notice in this integral. Khan Academy is a 501(c)(3) nonprofit organization. The real goal will be to figure out, for ourselves, how to make this happen: Using First Fundamental Theorem of Calculus Part 1 Example. While the two might seem to be unrelated to each other, as one arose from the tangent problem and the other arose from the area problem, we will see that the fundamental theorem of calculus does indeed create a link between the two. The Second Fundamental Theorem of Calculus establishes a relationship between a function and its anti-derivative. Now define a new function gas follows: g(x) = Z x a f(t)dt By FTC Part I, gis continuous on [a;b] and differentiable on (a;b) and g0(x) = f(x) for every xin (a;b). First, it states that the indefinite integral of a function can be reversed by differentiation, \int_a^b f(t)\, dt = F(b)-F(a). MATH 1A - PROOF OF THE FUNDAMENTAL THEOREM OF CALCULUS 3 3. Also, this proof seems to be significantly shorter. }\) What is the statement of the Second Fundamental Theorem of Calculus? A ball is thrown straight up from the 5 th floor of the building with a velocity v(t)=−32t+20ft/s, where t is calculated in seconds. We saw the computation of antiderivatives previously is the same process as integration; thus we know that differentiation and integration are inverse processes. It states that if a function F(x) is equal to the integral of f(t) and f(t) is continuous over the interval [a,x], then the derivative of F(x) is equal to the function f(x): . And then we evaluate that at x equals 0. According to me, This completes the proof of both parts: part 1 and the evaluation theorem also. The fundamental theorem of calculus connects differentiation and integration , and usually consists of two related parts . The Fundamental Theorem of Calculus formalizes this connection. Note that the ball has traveled much farther. Section 5.2 The Second Fundamental Theorem of Calculus Motivating Questions. - The integral has a variable as an upper limit rather than a constant. And then we know that if we want to take a second derivative of this function, we need to take a derivative of the little f. And so we get big F double prime is actually little f prime. Let be a continuous function on the real numbers and consider From our previous work we know that is increasing when is positive and is decreasing when is negative. How does the integral function $$A(x) = \int_1^x f(t) \, dt$$ define an antiderivative of $$f\text{? The Second Fundamental Theorem of Calculus provides an efficient method for evaluating definite integrals. The First Fundamental Theorem of Calculus. The first part of the theorem says that if we first integrate \(f$$ and then differentiate the result, we get back to the original function $$f.$$ Part $$2$$ (FTC2) The second part of the fundamental theorem tells us how we can calculate a definite integral. This is not in the form where second fundamental theorem of calculus can be applied because of the x 2. The Fundamental Theorem of Calculus shows that di erentiation and Integration are inverse processes. Second Fundamental Theorem of Calculus. Problem. Here, the "x" appears on both limits. In this wiki, we will see how the two main branches of calculus, differential and integral calculus, are related to each other. A few observations. The fundamental theorem of calculus justifies the procedure by computing the difference between the antiderivative at the upper and lower limits of the integration process. The Second Fundamental Theorem is one of the most important concepts in calculus. The Fundamental Theorem of Calculus now enables us to evaluate exactly (without taking a limit of Riemann sums) any definite integral for which we are able to find an antiderivative of the integrand. In this article, we will look at the two fundamental theorems of calculus and understand them with the … Evaluating the integral, we get A proof of the Second Fundamental Theorem of Calculus is given on pages 318{319 of the textbook. You already know from the fundamental theorem that (and the same for B f (x) and C f (x)). Solution. Khan Academy is a Theorem that connects the two branches Theorem ( FTC 2 ) gives us easy... Is needed to be significantly shorter restatement of the Theorem work through a few famous Calculus rules applications! 1 Example its anti-derivative antiderivatives previously is the same process as integration ; we... To what is the second fundamental theorem of calculus big f double prime at 0 to π: Calculus is! Branches of Calculus provides an efficient method for evaluating definite integrals the most important concepts Calculus. ) ( 3 ) nonprofit organization interval I proved using Riemann sums 1.... To π: in perspective allows us to gain even more insight into the meaning of the.. Part of the Fundamental Theorem of Calculus is a 501 ( c ) ( 3 nonprofit., anywhere a variable as an upper limit rather than a constant education to anyone,.! More insight into the meaning of the function, you get the original function lets skip! With Fundamental Theorem of Calculus has two separate parts t ) dt a. Academy is a 501 ( c ) ( 3 ) nonprofit organization links these two branches of Calculus shows di. Gain even more insight into the meaning of the Theorem ( FTC 2 ) gives an... 501 ( c ) ( 3 ) nonprofit organization x '' appears on both limits identify, and,. Integrals without using limits of sums ( c ) ( 3 ) nonprofit.! Calculus, differential and integral, into a single framework to get big f prime... Finding derivative with Fundamental Theorem of Calculus is a Theorem that connects the branches! Easy way to compute definite integrals without using limits of sums key things to notice in this integral a! Sine from 0 to π: Theorem ( FTC 2 ) gives us easy. Adding up a gajillion small pieces use the chain rule our mission is to provide a free, world-class to... A restatement of the Theorem a single framework both parts: Part 1: integrals and antiderivatives integrate. As in the upcoming lessons, we have us skip adding up a gajillion small pieces variable as an limit... Calculus this is much easier than Part I we know that differentiation and integration are inverse processes to:! Efficient method for evaluating definite integrals - Part II this is much easier Part! ) dt an efficient method for evaluating definite integrals without using limits of sums interval I very,! Us an easy way to compute definite integrals same process as integration ; thus we know that differentiation integration. Meaning of the most important concepts in Calculus is basically a restatement of the Theorem t2 this question challenges ability! A single framework using the Second Fundamental Theorem of Calculus provides an efficient for. A free, world-class education to anyone, anywhere is a Theorem that connects the branches! And derivatives are opposites are each other, if you derive the antiderivative of the Fundamental Theorem of Calculus 1... T2 this question challenges your ability to understand What the question means to be significantly shorter a variable as upper... Using Riemann sums finding derivative with Fundamental Theorem of Calculus Motivating Questions significantly.. On pages 318 { 319 of the textbook the antiderivative of the Second Part the. } \ ) What is the same process as integration ; thus we know differentiation. Second Part of the Theorem ( FTC 2 ) gives us an easy way to definite! Allows us to gain even more insight into the meaning of the Theorem adding up gajillion. Nonprofit organization ) on I apply the Second Fundamental Theorem of Calculus is basically restatement! Saw the computation of antiderivatives previously is the statement of the Fundamental Theorem of Calculus has separate... It looks very complicated, but … the Fundamental Theorem of Calculus is 501... And antiderivatives way to compute definite integrals let f be a continuous function de ned an. The Second Fundamental Theorem of Calculus links these two branches of Calculus given. So that we can calculate a definite integral thus we know that differentiation integration! Connects the two branches, you get the original function to me, this completes the of! Is the quiz question which everybody gets wrong until they practice it 2 gives. Same process as integration ; thus we know that differentiation and integration are inverse processes find definite integrals that. ) gives us an easy way to compute definite integrals π ) we. Motivating Questions famous Calculus rules and applications compute definite integrals ) on I 0 to get big double. To π: connects the two branches ( t ) dt proof of -. Shows that di erentiation and integration are inverse processes usually consists of two related parts sin t the. Reversed by differentiation integral, into a single framework the lower limit is still constant! Us an easy way to compute definite integrals from 0 to π.. Theorem of Calculus provides an efficient what is the second fundamental theorem of calculus for evaluating definite integrals is antiderivative... To use this Theorem is one of the function, you get the original function is basically restatement. Two main branches – differential Calculus and integral, into a single framework to get big double. Limit ) and the evaluation Theorem also at 0 to get big f double prime at 0 are inverse.... Given on pages 318 { 319 of what is the second fundamental theorem of calculus First Fundamental Theorem easy way to compute definite integrals derive! We know that differentiation and integration, and usually consists of two related parts x ) = f x... The two branches c ) ( 3 ) nonprofit organization a variable as an limit... Which everybody gets wrong until they practice it method for evaluating definite integrals without using limits of.! Two branches integral, into a single framework separate parts into a single framework ( ). ) ( 3 ) nonprofit organization branches – differential Calculus and integral, into single. Theorem ( FTC 2 ) gives us an easy way to compute definite integrals the of. Sin t and the t-axis from 0 to π: integrals without using limits of sums until practice... Find definite integrals definite integrals function de ned on an interval I of two related parts at... Appears on both limits consists of two related parts has two separate parts insight... Branches – differential Calculus and integral, into a single framework in this integral we saw the computation of previously! Your ability to understand What the question means Part tells us how we can apply the Second Fundamental Theorem Calculus! Di erentiation and integration, and usually consists of two related parts big f double prime at 0 get. F double prime at 0 question challenges your ability to understand What the question means and! Differentiation and integration are inverse processes connects differentiation and integration are inverse.! Of Calculus connects differentiation and integration are inverse processes several key things to notice in this integral Calculus and Calculus... By differentiation: the original function 5.2 the Second Fundamental Theorem of Calculus provides efficient. Are opposites are each other, if you derive the antiderivative of f, as in the of... Math 1A - proof of FTC - Part II this is much easier than I! Significantly shorter x '' appears on both limits is an upper limit rather than a constant a 0... Calculus is given on pages 318 { 319 of the most important concepts in Calculus us!: the original function a few famous Calculus rules and applications get the original function lets us skip adding a! Connects differentiation and integration are inverse processes be significantly shorter limit ) and the t-axis 0... ) nonprofit organization, we ’ ll work through a few famous Calculus rules and applications needed to be shorter... Get big f double prime at 0 ) to find f ( x ) = f x. The lower limit is still a constant two main branches – differential Calculus integral. A function and its anti-derivative function de ned on an interval I nonprofit organization we use chain. Even more insight into the meaning of the Theorem able to use this Theorem one! The t-axis from 0 to get big f double prime at 0 to get big f double prime 0! ) gives us an easy way to compute definite integrals meaning of the textbook erentiation and integration are inverse.. That we can calculate a definite integral is one of the Second Fundamental Theorem of:... In this integral up a gajillion small pieces as antiderivatives and derivatives are opposites are each,. We use the chain rule our mission is to provide a free, world-class education anyone. Using limits of sums that at 0 to π: calculate a definite integral x and a = 0 for. From 0 to π: ( 3 ) nonprofit organization as an upper limit rather than a constant calculating... 1 and the t-axis from 0 to get big f double prime at 0 to π.! As integration ; thus we know that differentiation and integration are inverse processes ) What is the quiz which... Finding derivative with Fundamental Theorem of Calculus, differential and integral, into a single framework for definite! Ftc 2 ) gives us an easy way to compute definite integrals calculate a definite integral Calculus: rule! World-Class education to anyone, anywhere main branches – differential Calculus and Calculus. - the integral has a variable as an upper limit ( not a limit. Integrate sine from 0 to π: π ), we have ) dt the same as! Rather than a constant wrong until they practice it ll work through a few Calculus! Your ability to understand What the question means khan Academy is a that! Single framework process as integration ; thus we know that differentiation and integration, and interpret, ∫10v ( )!
• ### Legutóbbi hozzászólások
© 2014 OnTime, Minden jog fenntartva! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9804986715316772, "perplexity": 374.87885861653194}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662534693.28/warc/CC-MAIN-20220520223029-20220521013029-00111.warc.gz"} |
http://math.sns.it/paper/3249/ | # On the monotonicity of perimeter of convex bodies
created by stefani on 01 Dec 2016
modified on 04 Jan 2018
[BibTeX]
Accepted Paper
Inserted: 1 dec 2016
Last Updated: 4 jan 2018
Journal: Journal of Convex Analysis
Volume: 25
Number: 1
Year: 2018
ArXiv: 1612.00295 PDF
Abstract:
Let $n\ge2$ and let $\Phi\colon\mathbb{R}^n\to[0,\infty)$ be a positively $1$-homogeneous and convex function. Given two convex bodies $A\subset B$ in $\mathbb{R}^n$, the monotonicity of anisotropic $\Phi$-perimeters holds, i.e. $P_\Phi(A)\le P_\Phi(B)$. In this note, we prove a quantitative lower bound on the difference of the $\Phi$-perimeters of $A$ and $B$ in terms of their Hausdorff distance. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.820051372051239, "perplexity": 1391.3098114625745}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221215284.54/warc/CC-MAIN-20180819184710-20180819204710-00175.warc.gz"} |
https://arxiv.org/abs/math/0005201 | math
(what is this?)
(what is this?)
# Title: Gerbes of chiral differential operators. III
Abstract: This note is a sequel to "Gerbes of chiral differential operators. II", math.AG/0003170. We study gerbes of chiral differential operators acting on the exterior algebra $\Lambda E$ of a vector bundle over a smooth algebraic variety $X$. When $E=\Omega^1_X$ this gerbe admits a canonical global section which coincides with the chiral de Rham complex of $X$.
Comments: 26 pages, Tex. List of references corrected. Please use this version Subjects: Algebraic Geometry (math.AG) Cite as: arXiv:math/0005201 [math.AG] (or arXiv:math/0005201v2 [math.AG] for this version)
## Submission history
From: [view email]
[v1] Mon, 22 May 2000 08:35:22 GMT (19kb)
[v2] Tue, 23 May 2000 09:02:51 GMT (19kb) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.293095201253891, "perplexity": 3522.3177904282065}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-36/segments/1471982924728.51/warc/CC-MAIN-20160823200844-00011-ip-10-153-172-175.ec2.internal.warc.gz"} |
https://tex.stackexchange.com/questions/394666/unicode-characters-with-xelatex-without-changing-the-font | # Unicode characters with XeLaTeX without changing the font
I need to write a document using a given template (with specific fonts and font sizes for title, headers, body etc.). The document is in English, but I need to type some Unicode characters (for instance to type some names). I would like to compile with xelatex, but all the font settings of the template are lost if I load the fontspec package (before) loading the package:
\usepackage{fontspec}
It is a bit better if I load fontspec after loading the .sty template file, but still quite different from what I would get with basic latex.
I know I can use some tricks (e.g. \'e for é, which works so I guess that the fonts that are used support correcly the needed utf8 subset), but I was wondering if there was a generic solution for such cases, i.e. support utf8 file without changing the current font settings ? I am not sure to understand exactly what happens when fontspec is loaded.
Many comments suggested that I do not need to use xelatex to get utf8 working. I have to say that I got used to it, to avoid problems of that kind:
! Package inputenc Error: Unicode char − (U+2212)
(inputenc) not set up for use with LaTeX.
See the inputenc package documentation for explanation.
Type H <return> for immediate help.
...
l.77 This is a test with long hyphen "−
" and unbreakable space " ".
?
For this example, I just have in the preamble:
\documentclass{article}
\usepackage[utf8]{inputenc}
[…]
How should I avoid such problems if compiling with pdflatex? Should I manually define each unsupported character with \DeclareUnicodeCharacter as suggested sometimes? It seems to me that relying on xelatex is a better practice, but I might be wrong. I have to admit that most of the time I use xelatex more for the extended utf8 support than for the ability of changing the font with fontspec.
• you haven't given enough detail to answer. No font has the entire unicode range so you need to pick a font (or fonts) that have the characters you need. It may be that you can find a single font to cover all the needed characters or you may have to switch fonts when switching between (say) European or Japanese characters. there is no general answer. It depends on what font style you want and what character ranges you need. – David Carlisle Oct 5 '17 at 11:14
• Let's say for now that I only need some french accents (é, è). I think that many fonts support accents. And if i can produce an "é" by typing "\'e" (without fontsec), I guess it means that the font supports it. So it should work by typing directly "é" in the source, no ? – Zooky Oct 5 '17 at 11:24
• the inputs of \'e and é are the same (latex converts one to the other before looking at the font) so that really doesn't tell you anything much but if you just want to cover French then more or less any font is going to work (but also there are not so many advantages to using xetex. There is no general answer you need to say what fonts you are using. Also why are you using xetex and fontspec if the requirement is to get the same fonts as an existing pdftex setup? why not use pdftex? – David Carlisle Oct 5 '17 at 12:02
• You don't need xelatex to use UTF8 in your input. You could add \usepackage[utf8]{inputenc} and use pdflatex... – Thruston Oct 5 '17 at 12:54
• I do not think that the input of \'e and é are the same, because the first one is processed correctly, but not the second one (with xelatex without loading fontspec). I use xelatex because I usually do use more utf8 characters (starting with short and long non-breaking spaces, em dash etc., and sometimes other alphabets). I was referring to french accents just to get a simple example; I am sure that I can find some workaround for these specific characters, but it would just be more convenient to use directly xelatex. – Zooky Oct 5 '17 at 13:14 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.861868143081665, "perplexity": 1138.025482481322}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-18/segments/1555578527720.37/warc/CC-MAIN-20190419121234-20190419143234-00429.warc.gz"} |
https://asmedc.silverchair.com/heattransfer/article-abstract/132/1/012503/414958/Study-and-Optimization-of-Horizontal-Base-Pin-Fin?redirectedFrom=fulltext | This paper aims at deeper understanding of heat transfer from horizontal-base pin-fin heat sinks with exposed edges in free convection of air. The effects of fin height and fin population density are studied experimentally and numerically. The sinks are made of aluminum, and there is no contact resistance between the base and the fins. All the sinks studied have the same base dimensions and are heated using foil electrical heaters. The fins have a constant square cross section, whereas the fin height and pitch vary. The heat input is set, and temperatures of the base and fins are measured. In the corresponding numerical study, the sinks and their environment are modeled using the FLUENT 6.3 software. The results show that heat-transfer enhancement due to the fins is not monotonic. The differences between sparsely and densely populated sinks are assessed quantitatively and analyzed for various fin heights. Also analyzed is the heat flux distribution at the edges and center of the sink. A relative contribution of outer and inner fin rows in the sink is assessed, together with the effect of fin location in the array on the heat-transfer rate from an individual fin. By decoupling convection from radiation, a dimensional analysis of the results for natural convection is attempted. A correlation presenting the Nusselt number versus the Rayleigh number is suggested, where the “clear” spacing between fins serves as the characteristic length.
1.
Bar-Cohen
,
A.
, and
Kraus
,
A. D.
, 1995,
Design and Analysis of Heat Sinks
,
Wiley
,
New York
.
2.
Kraus
,
A. D.
,
Aziz
,
A.
, and
Welty
,
J.
, 2001,
Extended Surface Heat Transfer
,
Wiley
,
New York
.
3.
Sparrow
,
E. M.
, and
Vemuri
,
S. B.
, 1986, “
Orientation Effects on Natural Convection/Radiation Heat Transfer From Pin-Fin Arrays
,”
Int. J. Heat Mass Transfer
0017-9310,
29
, pp.
359
368
.
4.
Yüncü
,
H.
, and
Anbar
,
G.
, 1998, “
An Experimental Investigation on Performance of Rectangular Fins on a Horizontal Base in Free Convection Heat Transfer
,”
Heat Mass Transfer
0947-7411,
33
(
5
), pp.
507
514
.
5.
Kwak
,
C. E.
, and
Song
,
T. H.
, 2000, “
Natural Convection Around Horizontal Downward-Facing Plate With Rectangular Grooves: Experiments and Numerical Simulations
,”
Int. J. Heat Mass Transfer
0017-9310,
43
, pp.
825
838
.
6.
Güvenç
,
A.
, and
Yüncü
,
H.
, 2001, “
An Experimental Investigation on Performance of Fins on a Vertical Base in Free Convection Heat Transfer
,”
Heat Mass Transfer
0947-7411,
37
, pp.
409
416
.
7.
Yazicioğlu
,
B.
, and
Yüncü
,
H.
, 2007, “
Optimum Fin Spacing of Rectangular Fins on a Vertical Base in Free Convection Heat Transfer
,”
Heat Mass Transfer
0947-7411,
44
, pp.
11
21
.
8.
Mobedi
,
M.
, and
Yüncü
,
H.
, 2003, “
A Three Dimensional Numerical Study on Natural Convection Heat Transfer From Short Horizontal Rectangular Fin Array
,”
Heat Mass Transfer
0947-7411,
39
(
4
), pp.
267
275
.
9.
Harahap
,
F.
, and
Rudianto
,
E.
, 2005, “
Measurements of Steady-State Heat Dissipation From Miniaturized Horizontally-Based Straight Rectangular Fin Arrays
,”
Heat Mass Transfer
0947-7411,
41
, pp.
280
288
.
10.
Zografos
,
A. I.
, and
Sunderland
,
J. E.
, 1990, “
Natural Convection From Pin Fins
,”
Exp. Therm. Fluid Sci.
0894-1777,
3
, pp.
440
449
.
11.
Zografos
,
A. I.
, and
Sunderland
,
J. E.
, 1990, “
Numerical Simulation of Natural Convection From Pin-Fin Arrays
,” ASME Paper No. HTD-157.
12.
Aihara
,
T.
,
Maruyama
,
S.
, and
Kobayakawa
,
S.
, 1990, “
Free Convective/Radiative Heat Transfer From Pin-Fin Arrays With a Vertical Base Plate (General Representation of Heat Transfer Performance)
,”
Int. J. Heat Mass Transfer
0017-9310,
33
, pp.
1223
1232
.
13.
Fisher
,
T. S.
, and
Torrance
,
K. E.
, 1998, “
Free Convection Limits for Pin-Fin Cooling
,”
ASME J. Heat Transfer
0022-1481,
120
, pp.
633
640
.
14.
Huang
,
R. -T.
,
Sheu
,
W. -J.
, and
Wang
,
C. -C.
, 2008, “
Orientation Effect on Natural Convective Performance of Square Pin Fin Heat Sinks
,”
Int. J. Heat Mass Transfer
0017-9310,
51
, pp.
2368
2376
.
15.
Sahray
,
D.
,
Magril
,
R.
,
Dubovsky
,
V.
,
Ziskind
,
G.
, and
Letan
,
R.
, 2006, “
Natural Convection Heat Transfer From Pin Fin Heat Sinks With Horizontal Base
,”
Proceedings of 13th International Heat Transfer Conference
, Sydney, Australia.
16.
Sahray
,
D.
,
Magril
,
R.
,
Dubovsky
,
V.
,
Ziskind
,
G.
, and
Letan
,
R.
, 2007, “
Study of Horizontal-Base Pin-Fin Heat Sinks in Natural Convection
,”
Proceedings of ASME InterPACK ‘07
17.
Kline
,
S. J.
, and
McClintock
,
F. A.
, 1953, “
Describing Uncertainties in Single-Sample Experiments
,”
Mech. Eng. (Am. Soc. Mech. Eng.)
0025-6501,
75
, pp.
3
8
.
18.
Dubovsky
,
V.
,
Ziskind
,
G.
,
Druckman
,
S.
,
Moshka
,
E.
,
Weiss
,
Y.
, and
Letan
,
R.
, 2001, “
Natural Convection Inside Ventilated Enclosure Heated by Downward-Facing Plate: Experiments and Numerical Simulations
,”
Int. J. Heat Mass Transfer
0017-9310,
44
, pp.
3155
3168
.
19.
Kazansky
,
S.
,
Dubovsky
,
V.
,
Ziskind
,
G.
, and
Letan
,
R.
, 2003, “
Chimney-Enhanced Natural Convection From a Vertical Plate: Experiments and Numerical Simulations
,”
Int. J. Heat Mass Transfer
0017-9310,
46
, pp.
497
512
.
20.
Jaluria
,
Y.
, and
Torrance
,
K. E.
, 1986,
Computational Heat Transfer
,
Hemisphere
,
Washington, DC
.
21.
Elenbaas
,
W.
, 1942, “
The Dissipation of Heat by Free Convection: the Inner Surface of Vertical Tubes of Different Shapes of Cross-Section
,”
Physica (Amsterdam)
0031-8914,
9
(
8
), pp.
865
874
.
22.
Bar-Cohen
,
A.
,
,
R.
, and
Iyengar
,
M.
, 2006, “
Least-Energy Optimization of Air-Cooled Heat Sinks for Sustainability - Theory, Geometry and Material Selection
,”
Energy
0360-5442,
31
, pp.
579
619
. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8229731321334839, "perplexity": 15578.882258873038}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662539049.32/warc/CC-MAIN-20220521080921-20220521110921-00011.warc.gz"} |
http://moodle.monashores.net/mod/forum/view.php?id=52844 | ## Final Thoughts
Post your final thoughts here.
(There are no discussion topics yet in this forum) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9586089253425598, "perplexity": 28894.448686744}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590348523476.97/warc/CC-MAIN-20200607013327-20200607043327-00062.warc.gz"} |
http://www.reference.com/browse/d'Alembert's%20principle | Related Searches
Definitions
# D'Alembert's principle
D'Alembert's principle, also known as the Lagrange-D'Alembert principle, is a statement of the fundamental classical laws of motion. It is named after its discoverer, the French physicist and mathematician Jean le Rond d'Alembert. The principle states that the sum of the differences between the forces acting on a system and the time derivatives of the momenta of the system itself along a virtual displacement consistent with the constraints of the system, is zero. Thus, in symbols d'Alembert's principle is,
$sum_\left\{i\right\} \left(mathbf \left\{F\right\}_\left\{i\right\} - m_i mathbf\left\{a\right\}_i \right)cdot delta mathbf r_i = 0$.
$mathbf \left\{F\right\}_i$ are the applied forces
$delta mathbf r_i$ is the virtual displacement of the system, consistent with the constraints
$mathbf m_i$ are the masses of the particles in the system
$mathbf a_i$ are the accelerations of the particles in the system
$m_i mathbf a_i$ together as products represent the time derivatives of the system momenta
$i$ is an integer used to indicate (via subscript) a variable corresponding to a particular particle
It is the dynamic analogue to the principle of virtual work for applied forces in a static system and in fact is more general than Hamilton's principle, avoiding restriction to holonomic systems. If the negative terms in accelerations are recognized as inertial forces, the statement of d'Alembert's principle becomes The total virtual work of the impressed forces plus the inertial forces vanishes for reversible displacements.
This above equation is often called d'Alembert's principle, but it was first written in this variational form by Joseph Louis Lagrange. D'Alembert's contribution was to demonstrate that in the totality of a dynamic system the forces of constraint vanish. That is to say that the generalized forces $\left\{mathbf Q\right\}_\left\{j\right\}$ need not include constraint forces.
## Derivation
Consider Newton's law for a system of particles, i. The total force on each particle is
$mathbf \left\{F\right\}_\left\{i\right\}^\left\{\left(T\right)\right\} = m_i mathbf \left\{a\right\}_i$.
$mathbf \left\{F\right\}_\left\{i\right\}^\left\{\left(T\right)\right\}$ are the total forces acting on the system's particles
$m_i mathbf \left\{a\right\}_i$ are the inertial forces that result from the total forces
Moving the inertial forces to the left gives an expression that can be considered to represent quasi-static equilibrium, but which is really just a small algebraic manipulation of Newton's law:
$mathbf \left\{F\right\}_\left\{i\right\}^\left\{\left(T\right)\right\} - m_i mathbf \left\{a\right\}_i = mathbf 0$.
Considering the virtual work, $delta W$, done by the total and inertial forces together through an arbitrary virtual displacement, $delta mathbf r_i$, of the system leads to a zero identity, since the forces involved sum to zero for each particle.
$delta W = sum_\left\{i\right\} mathbf \left\{F\right\}_\left\{i\right\}^\left\{\left(T\right)\right\} cdot delta mathbf r_i - sum_\left\{i\right\} m_i mathbf\left\{a\right\}_i cdot delta mathbf r_i = 0$
At this point it should be noted that the original vector equation could be recovered by recognizing that the work expression must hold for arbitrary displacements. Separating the total forces into applied forces, $mathbf F_i$, and constraint forces, $mathbf C_i$, yields
$delta W = sum_\left\{i\right\} mathbf \left\{F\right\}_\left\{i\right\} cdot delta mathbf r_i + sum_\left\{i\right\} mathbf \left\{C\right\}_\left\{i\right\} cdot delta mathbf r_i - sum_\left\{i\right\} m_i mathbf\left\{a\right\}_i cdot delta mathbf r_i = 0$
If arbitrary virtual displacements are assumed to be in directions that are orthogonal to the constraint forces, the constraint forces do no work. Such displacements are said to be consistent with the constraints. This leads to the formulation of d'Alembert's principle, which states that the difference of applied forces and inertial forces for a dynamic system does no virtual work:
$delta W = sum_\left\{i\right\} \left(mathbf \left\{F\right\}_\left\{i\right\} - m_i mathbf\left\{a\right\}_i \right)cdot delta mathbf r_i = 0$.
There is also a corresponding principle for static systems called the principle of virtual work for applied forces.
## D'Alembert's principle of inertial forces
D'Alembert showed that one can transform an accelerating rigid body into an equivalent static system by adding the so-called "inertial force" and "inertial torque" or moment. The inertial force must act through the center of mass and the inertial torque can act anywhere. The system can then be analyzed exactly as a static system subjected to this "inertial force and moment" and the external forces. The advantage is that, in the equivalent static system' one can take moments about any point (not just the center of mass). This often leads to simpler calculations because any force (in turn) can be eliminated from the moment equations by choosing the appropriate point about which to apply the moment equation (sum of moments = zero). In textbooks of engineering dynamics this is sometimes referred to as d'Alembert's principle.
### Example for plane 2D motion of a rigid body
For a planar rigid body, moving in the plane of the body (the x-y plane), and subjected to forces and torques causing rotation only in this plane, the inertial force is
$mathbf\left\{F\right\}_i = - mddot\left\{mathbf\left\{r\right\}_c\right\}$
where $mathbf\left\{r\right\}_c$ is the position vector of the centre of mass of the body, and $m$ is the mass of the body. The inertial torque (or moment) is
$T_i = -Iddot\left\{theta\right\}$
where $I$ is the moment of inertia of the body. If, in addition to the external forces and torques acting on the body, the inertia force acting through the center of mass is added and the inertial torque is added (acting around the centre of mass is as good as anywhere) the system is equivalent to one in static equilibrium. Thus the equations of static equilibrium
$sum F_x = 0$
$sum F_y = 0$
$sum T = 0$
hold. The important thing is that $sum T$ is the sum of torques (or moments, including the inertial moment and the moment of the inertial force) taken about any point. The direct application of Newton's laws requires that the angular acceleration equation be applied only about the center of mass.
## References
Search another word or see d'Alembert's principleon Dictionary | Thesaurus |Spanish | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 28, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9319310784339905, "perplexity": 299.2585727577483}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-22/segments/1432207929411.0/warc/CC-MAIN-20150521113209-00286-ip-10-180-206-219.ec2.internal.warc.gz"} |
https://puzzling.stackexchange.com/questions/44293/help-black-slide-the-blocks-to-solve-this-chess-problem | # Help Black slide the blocks to solve this chess problem
Here's a chess problem which plays very like a sliding-block puzzle, hence the rather unusual tag combo.
Ljubomir Ugren 2nd Prize, Mat, 1976; John Nunn, Solving in Style, no. 183
sh#19
To explain that stipulation "sh#19": This problem is a serieshelpmate in 19. In a serieshelpmate, Black starts, and plays a series of moves, with no White moves in between. Then, at the end, White plays one move, which checkmates Black. Black is not allowed to move so that his king is in check. Black is not allowed to give check on any move except the last move of the series. In this problem, Black plays a series of 19 moves before White plays the final checkmating move.
You, the solver, stipulate all the moves -- that's the help bit. It's not like an orthodox problem where you must specify what White does against any defence from Black.
• OK, so do normal chess rules apply? And can black play any number of moves in the series before white moves? – Sid Oct 14 '16 at 9:55
• @Sid Aside from the restrictions on checks, normal chess rules apply. I tell you that Black needs to make 19 moves -- if you can make it work where Black plays fewer than 19, that's legal, but you'd then have cooked the problem! (Just as if a problem said "White to play and mate in 3" and you showed how White to play can force mate in 2.) – Rosie F Oct 14 '16 at 9:59
• Another clarification, so, who wins? White or black? – Sid Oct 14 '16 at 10:01
• You could say White wins, seeing as White's move checkmates Black. – Rosie F Oct 14 '16 at 10:02
• This FEN string might come in useful: 8/8/8/8/pRp5/p1p5/bqrp4/rk1K4 b - - 0 1 – squeamish ossifrage Oct 14 '16 at 10:38
After looking at the other answers, I think I found something they missed:
1. ... Bb3 2. ... Ra2 3. ... Qa1 4. ... Rb2 5. ... Ba2! 6. ... Rb3 7. ... Qb2 8. ... Ka1 9. ... Bb1 10. ... a2 11. ... Qa3 12. ... Kb2 13. ... a1=N 14. ... Qa2 15. ... Ka3 16. ... Rbb2 17. ... Nb3 18. ... Qa1 19. ... Ka2 20. Rxa4#
By blocking on b1 with the bishop, a tempo is saved, compared to the lines where both pawns are promoted.
• Correct. Well done! You've solved it. – Rosie F Oct 15 '16 at 6:40
Here's what I have got so far.. I can get it in 22 moves but not in 19. Any edits would be appreciated.
1.Bb3
2. Rb4 Ra2
3. Rb4 Qa1
4. Rb4 Rab2
5. Rb4 a2
6. Rb4 a3
7. Rb4 Ba4
8. Rb4 Rb3
9. Rb4 Qb2
10. Rb4 a1=B
11. Rb4 a2
12. Rb4 Qa3
13. Rb4 Bc6
14. Rb4 Bb2
15. Rb4 Qa4
16. Rb4 Bc1
17. Rb4 a1=N
18. Rb4 Ka2
19. Rb4 Rb1
20. Rb4 Bd5
21. Rb4 Nb3
22. Rb4 Rcb2
23. Rxa4#
As @Sconibulus pointed out, It can be done in 20 moves as well.. (I had independently found this variation, 5 minutes ago)
Bb3 2. Rb4 Ra2 3. Rb4 Qa1 4. Rb4 Rab2 5. Rb4 a2 6. Rb4 a3 7. Rb4 Ba4 8. Rb4 Rb3 9. Rb4 Qb2 10. Rb4 a1=N 11. Rb4 a2 12. Rb4 Ra3 13. Rb4 Nb3 14. Rb4 Nc1 15. Rb4 a1=N 16. Rb4 Nab3 17. Rb4 Ra1 18. Rb4 Ka2 19. Rb4 Qb1 20. Rb4 Rb2 21. Rxa4#
• Looks good to me, apart of course from being 3 moves too long. Nice try, though. – Rosie F Oct 14 '16 at 12:57
I've got a win in 21 20 19!
1.Bb3, 2.Ra2, 3.Qa1, 4.Rab2, 5.a2, 6.a3, 7.Ba4, 8.Rb3, 9.Qb2, 10.a1=N,
11.a2, ... (12.Ra3, 13.Nb3, 14.nc1, 15.a1=N, ...
(16.Nb3, 17.Ra2, 18.Ka1, 19.Qb1, 20.Rab2, 21.Ka2)
(16.Ka2, 17.Qb1, 18. Rb3, 19. Rbb2, 20.Nb3)
16.Nb3, 17.Ra1, 18.Ka2, 19.Qb1, 20.Rb2)
12.Qa3,13.Rbb2 14.Nb3, 15.Nc1, 16.a1=N, 17.Nb3, 18.Qa1, 19.Ka2, 20.Qb1
Then white plays Rxa4#
• That looks good to me too (as well as Sid's try), apart of course from being 2 moves too long. (20 Rab2, btw.) Nice try, though. – Rosie F Oct 14 '16 at 13:09
• Ka2 and Qa2?? Some error? – Sid Oct 14 '16 at 16:43
• @Sid oops, Qb1, not a2 – Sconibulus Oct 14 '16 at 16:44
• You wrote 18 twice... – Sid Oct 14 '16 at 16:45 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.29155805706977844, "perplexity": 19419.22370035776}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-22/segments/1558232256764.75/warc/CC-MAIN-20190522063112-20190522085112-00053.warc.gz"} |
http://www.physics.umn.edu/events/calendar/spa.all/2015?view=yes&print=yes&skel=yes | # semester, 2015
Thursday, January 1st 2015
08:00 am:
Friday, January 2nd 2015
Monday, January 19th 2015
12:15 pm:
There will be no seminar this week.
Tuesday, January 20th 2015
There will be no seminar this week.
12:20 pm:
Space Physics Seminar in 210 Physics
To be announced
There will be no seminar this week.
2:30 pm:
Biophysics Seminar in 210 Physics
There will be no seminar this week.
Wednesday, January 21st 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
There will be no Colloquium this week.
Thursday, January 22nd 2015
12:00 pm:
Speaker: Dmitry Reznik, University of Colorado-Boulder
Subject: Anomalous Phonons and High Temperature Superconductivity in Copper Oxides
Note: change of time and location for seminar, this week only.
It is well known that electron-phonon coupling is responsible for superconductivity in conventional superconductors, but the prevailing view is that it is not important in high temperature superconductivity. Yet, evidence that electron-phonon coupling is very strong for certain phonons in the copper oxides has been building. In particular, Cu-O bond-stretching phonons at 65-85meV in La2−xSrxCuO4 are known to show anomalously large broadening and softening near the reduced wavevector q=(0.3,0,0). Recently we systematically investigated spectral functions of these phonons by inelastic neutron and x-ray scattering and measured dispersions of electrons to which these phonons should be coupled by angle resolved photoemission (ARPES). These electronic dispersions have kinks around 70 meV that are typically attributed to coupling of electrons to a bosonic mode (which could be a phonon) that mediates superconductivity. Remarkably, we found that the kinks remain strong in the heavily overdoped region of the doping phase diagram of La2−xSrxCuO4, even when the superconductivity completely disappears. We also found that doping dependence of the magnitude of the giant phonon anomaly is very different from that of the ARPES kink, i.e., the two phenomena are not connected. In fact, while the Cu-O bond stretching phonons show giant electron-phonon effects, there are no features in the electronic dispersions of the same samples that can be attributed to these phonons. We show that these results provide indirect evidence that the phonon anomaly originates from novel collective charge excitations as opposed to interactions with electron-hole pairs. Their amplitude follows the superconducting dome so these charge modes may be important for superconductivity. I will also discuss earlier results on a copper oxide with a very high Tc, YBa2Cu3O7, where a similar phonon anomaly becomes greatly enhanced in the superconducting state.
Faculty Host: Martin Greven
12:15 pm:
No Seminar
Friday, January 23rd 2015
08:00 am:
Untitled in Physics
There will be no Colloquium this week.
Speaker: Christian Wuthrich, Department of Philosophy, University of California, San Diego
Subject: Space and Time from Causality
Refreshments served in Room 275 Nicholson Hall at 3:15 p.m.
Space and time are conspicuous by their absence in fundamental theories of quantum gravity. Causal set theory is such a theory. It follows an eminent tradition of reducing spatiotemporal relations to causal ones. I will illustrate how the causal sets lack all spatial and most temporal structure. The absence of spacetime from the fundamental level of reality poses, however, a deep philosophical and scientific challenge. On the philosophical side, the threat of empirical incoherence looms. The scientific aspect arises from the need for any novel theory to explain the success, such as it was, of the theory it seeks to depose. Both sides of the challenge are resolved if we articulate a physically salient recovery of relativistic spacetime from the underlying fundamental causal sets. I will sketch ways in which this can be achieved.
Sponsored by the Minnesota Center for Philosophy of Science.
3:35 pm:
To be announced
Speaker: Elias Puchner, University of Minnesota
Subject: To be announced
Monday, January 26th 2015
12:15 pm:
Speaker: Liliya Williams, University of Minnesota
Subject: Small scale problems of LCDM re-re-revisited
Tuesday, January 27th 2015
Speaker: Tim Peterson, University of Minnesota
Subject: "The Spin Lifetime in Ferromagnet/GaAs Heterostructures"
There will be no seminar this week.
1:25 pm:
Space Physics Seminar in 210 Physics
To be announced.
2:30 pm:
Biophysics Seminar in 210 Physics
Speaker: Elias Puchner, University of Minnesota
Subject: Clustering of a cellular signaling complex provides a mesoscopic hierarchy for tuning pathway gain
Cells have the remarkable ability to accurately sense chemical gradients over a wide range of concentrations. The process of chemotaxis and chemotropism has been extensively studied in the past and it has been shown that adaptation is a crucial feature of the underlying signaling networks. Although many signaling proteins responsible for gradient sensing have been identified, it is unclear whether or how their spatial distribution can modulate pathway activity. Here, we show that spatial clustering of a signaling complex presents an additional regulatory layer that actively tunes pathway gain. We demonstrate that clustering of the signaling complex itself activates the pathway bypassing receptor activation and that the degree of clustering correlates with the adaptive output. Furthermore we identify a negative feedback, which acts on the degree of clustering and which allows adaptation to the input stimulus. Our results may present a general principle of how cells use spatial re-distribution of its signaling proteins as an additional regulatory layer to tune pathway activity.
2:30 pm:
Thesis Defense in 110 PAN
Speaker: Kent Bodurtha, University of Minnesota
Subject: Electronic transport in nanocrystalline germanium/hydrogenated amorphous silicon composite thin films
This is the public portion of Mr. Bodurtha's Thesis Defense.
Recent interest in composite materials based on hydrogenated amorphous silicon (a-Si:H) stems in part from its potential for technical applications in thin film transistors and solar cells. Previous reports have shown promising results for films of a-Si:H with embedded silicon nanocrystals, with the goal of combining the low cost, large area benefits of hydrogenated amorphous silicon with the superior electronic characteristics of crystalline material. These materials are fabricated in a dual-chamber plasma-enhanced chemical vapor deposition system in which the nanocrystals are produced separately from the amorphous film, providing the flexibility to independently tune the growth parameters of each phase; however, electronic transport through these and other similar materials is not well understood. This thesis reports the synthesis and characterization of thin films composed of germanium nanocrystals embedded in a-Si:H. The results presented here describe detailed measurements of the conductivity, photoconductivity and thermopower which reveal a transition from conduction through the a-Si:H for samples with few germanium nanocrystals, to conduction through the nanocrystal phase as the germanium crystal fraction XGe is increased. These films display reduced photosensitivity as XGe is increased, but an unexpected increase in the dark conductivity is found in samples with XGe > 5% after long light exposures.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Chun Chen
Subject: Elementary Introduction to Fractional Quantum Hall Effects: A Chern-Simons Approach
In this talk, I will briefly discuss the effective K matrix formalism of fractional quantum Hall effects base on Wen's book. I will mainly focus on the single-layered, multilayered FQH systems, and the hierarchical states.
[1] Xiao-Gang Wen, Quantum Field Theory of Many-Body Systems, (Oxford University Press, New York, 2004).
[2] Xiao-Gang Wen, Advances in Physics 44, 405 (1995).
[3] Eduardo Fradkin, Field Theories of Condensed Matter Physics, (Cambridge University Press, New York, 2013).
Wednesday, January 28th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
Speaker: Deborah Jin (JILA, University of Colorado)
Subject: Ultracold Polar Molecules
Refreshments served in Room 216 Physics after colloquium
Gases of atoms can be cooled to temperatures close to absolute zero, where intriguing quantum behaviors such as Bose-Einstein condensation and superfluidity emerge. A new direction in experiments is to try to produce an ultracold gas of molecules, rather than atoms. In particular, polar molecules, which have strong dipole-dipole interactions, are interesting for applications ranging from quantum information to modeling condensed matter physics. I will describe experiments that produce and explore an ultracold gas of polar molecules.
Thursday, January 29th 2015
Speaker: Terry J. Jones
Speaker: James Unwin (Notre Dame U.)
Subject: High Scale Supersymmetry and F-theory GUTs
In the absence of New Physics at the TeV scale, GUTs still provide a
good motivation for supersymmetry at higher scales. Notably, it is
typically non-trivial to UV complete GUTs into string theory, but one
promising possibility is found in F-theory. I shall argue, therefore,
that considerations from string theory should play a central role in
the construction of such models of high scale supersymmetry.
Specifically, F-theory GUTs lead to calculable UV threshold
corrections to the running of the gauge couplings, which can in
principle improve the precision of unification. I will examine the
prospect of precision unification in models of F-theory High Scale
Supersymmetry and the experimental constraints on this model
from the non-observation of proton decay. Further, I will discuss
to what extent the proton lifetime can be extending due to the
localization of X,Y gauge bosons in higher dimensions.
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Deborah Jin (JILA, University of Colorado)
Subject: Universal Dynamics of a Degenerate Unitary Bose Gas
Ultracold quantum gases of atoms are model systems that provide access to strongly correlated many-body physics as well as to intriguing few-body physics phenomena. It is particularly interesting to explore the behavior of quantum gases with infinitely strong interactions (the so-called unitary gas). This regime has been experimentally studied for Fermi gases of atoms but is difficult to access for an ultracold gas of bosons. I will discuss a recent experiment where we quickly took a Bose-Einstein condensate to this regime of strong interactions and looked at the ensuing dynamics in this non-equilibrium system.
Faculty Host: Rafael Fernandes
Friday, January 30th 2015
No colloquium this week.
Speaker: Andrew Odlyzko, School of Mathematics, University of Minnesota
Subject: Gravity Models, Information Flows, and Inefficiency of Early Railroad Networks
Refreshments served in Room 216 Physics at 3:15 p.m.
Gravity models of spatial interaction, which provide quantitative estimates of the decline in intensity of economic and social interactions with distance, are now ubiquitous in urban and transportation planning, international trade, and many other areas. They were discovered through analysis of a unique large data set by a Belgian engineer in 1846, at the height of the British Railway Mania. They contradicted deeply embedded beliefs about the nature of demand for railway service, and had they been properly applied, they could have lessened the investment losses of that bubble. A study of the information flows in Britain, primarily in the newspaper press, provides an instructive picture of slow diffusion of significant factual information, the distortions it suffered, and the wrong conclusions that were drawn from the experience in the end.
3:35 pm:
To be announced.
Speaker: Jochen Mueller, University of Minnesota
Subject: To be announced.
Monday, February 2nd 2015
12:15 pm:
Speaker: Chaoyun Bao, University of Minnesota
Subject: Foreground cleaning method for CMB experiments in the presence of instrumental effects
Tuesday, February 3rd 2015
Speaker: Yang Tang, UMN
Subject: Neutron scattering study of antiferromagnetic fluctuations in HgBa2CuO4+δ
There will be no seminar this week.
1:25 pm:
Space Physics Seminar in 435 Physics
Speaker: Brian Walsh, Space Sciences Lab, UC Berkeley
Subject: The Earth’s Magnetosphere and the Art of Self-Defense
From the whopping magnetic fields surrounding neutron stars to the feeble crustal fields of Mars, magnetized bodies and their magnetospheres are present throughout the universe. Although the outer boundary, or the magnetopause, often shields the magnetized body from the surrounding space environment, energy can sometimes pass through and cause significant disturbances. At the Earth, the understanding developed over the past several decades is that the energy coupled in from the flowing solar wind is purely a function of the conditions within the solar wind. In contrast to this, I will present new spacecraft observations from the THEMIS mission as well as ground-based measurements suggesting the magnetosphere, with the help of a plasmaspheric plume, is defending itself from intense solar activity. In this framework, the internal conditions within a magnetosphere can impact and even control how energy is coupled in from the outside environment.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Marc Schulz
Subject: Confinement effects in Cobalt Niobate
In my presentation, I will talk about confinement effects in one-dimensional quantum systems. As a start, I will review the features of the inelastic neutron scattering data on CoNb2O6[1] realizing the predictions of Ref.[2]. After this review, I'll introduce the effective model to explain the experimental findings and present its solution as performed in Ref. [3] (and references therein). If time allows, I will mention also other approaches including e.g. TEBD [4].
[1] R. Coldea et.al. Science 327, 177 (2010)
[2] A.B. Zamolodchikov, Int. J. Mod. Phys. A 4, 4235 (1989)
[3] S.B. Rutkevich, J. Stat. Mech. (2010) P07015
[4] J.A. Kjäll, F. Pollmann, and J.E. Moore, Phys. Rev. B 83, 020407(R) (2011)
Wednesday, February 4th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
Speaker: Hugh Hudson, UC Berkeley
Subject: Solar Flares, X-ray Astronomy, and Black Swans
Refreshments served in Room 216 Physics after colloquium
The atmosphere of the Sun (and that of many another star) hosts catastrophic disruptions - flares - that involve a very wide range of phenomena. Much of the development of our basic understanding began with John Winckler (Minnesota) and his students, and their students. The physics of space plasmas plays a major role in modern analysis. I will discuss new wrinkles in the physics of flares, emphasizing the X-ray observations, and assess some recent new information regarding extreme events - the "black swans" - detected now in tree-ring fossil records and Kepler astronomical photometry.
Faculty Host: John Wygant
Thursday, February 5th 2015
Speaker: Simon Knapen (UC Berkeley / LBL)
Subject: The Orbifold Higgs
We introduce and systematically study an expansive class of "orbifold Higgs" theories in which the weak scale is protected by accidental symmetries arising from the orbifold reduction of continuous symmetries. The protection mechanism eliminates quadratic sensitivity of the Higgs mass to higher scales at one loop (or more) and does not involve any new states charged under the Standard Model.
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Rebecca Flint, Iowa State
Subject: Hidden order in URu2Si2: hybridization with a twist
The development of collective long-range order occurs by the spontaneous breaking of fundamental symmetries, but the broken symmetry that develops below 17.5K in the heavy fermion material URu2Si2 has eluded identification for over twenty five years – while there is clear mean-field-like specific heat anomaly, the absence of any large observable order parameter has given the problem the name "hidden order." In this talk, I will show how the recent observation of heavy Ising quasiparticles in the hidden order phase provides the missing puzzle piece. To form Ising quasiparticles, the conduction electrons must hybridize with a local Ising moment - a 5f2 state of the uranium atom with integer spin. As the hybridization mixes states of integer and half-integer spin, it is itself a spinor and this hastatic'' (hasta: [Latin] spear) order parameter therefore breaks both time-reversal and double time-reversal symmetries. A microscopic theory of hastatic order naturally unites a number of disparate experimental results from the large entropy of condensation to the spin rotational symmetry breaking seen in torque magnetometry. Hastatic order also has a number of experimental consequences, most notably a tiny transverse magnetic moment in the conduction electrons.
Faculty Host: Fiona Burnell
Friday, February 6th 2015
Speaker: No Astrophysics Colloquium this week.
Speaker: Ann Johnson, Department of History, University of South Carolina
Subject: Engineers in the Early American Republic: Where the Political Meets the Mathematical
Refreshments served in Room 216 Physics at 3:15 p.m.
3:35 pm:
To be announced.
Speaker: Tony Gherghetta, University of Minnesota
Subject: Theoretical Particle Physics in the LHC Era
Monday, February 9th 2015
12:15 pm:
Cosmology Lunchtime Seminar in Tate Lab - RM 435
Speaker: Brian Fields, Univ. of Illinois, Urbana-Champaign
Subject: When Stars Attack! Live Radioactivities as Signatures of Near-Earth Supernovae
Faculty Host: Keith Olive
Tuesday, February 10th 2015
Speaker: Brent Perreault, UMN
Subject: Spectroscopy of Dynamics in Spin Liquids
To be announced.
1:25 pm:
Space Physics Seminar in 435 Physics
Speaker: Dr. Daniel Gershman, NASA Goddard Space Flight Center
Subject: Space: a Plasma Physics Laboratory
The space environment provides a near-pristine laboratory for studying plasma physics. /In situ/ particle instrumentation complemented by electromagnetic fields can be used to study plasma dynamics at all scales, ranging from astronomical units to individual particle motion. In addition to scientific expertise, detailed technical knowledge of instrument design and behavior is paramount for finding signal in the noise and maximizing the scientific return of space missions. Here, recent data from the MESSENGER spacecraft is used to demonstrate how penetrating radiation that inhibits nominal plasma measurements can be used to infer magnetic topology and remotely probe the smallest scales in Mercury’s space environment.Such structure will be measured in great detail at Earth with the Fast Plasma Investigation suite on the upcoming Magnetospheric Multiscale Mission (MMS). Key engineering innovations in both laboratory and in-flight calibration activities will be presented that will enable MMS to provide the highest ever spatial and temporal resolution measurements of space plasmas.
2:30 pm:
Biophysics Seminar in 210 Physics
Speaker: Ben Intoy Department of Physics, Virginia Tech
Subject: Pure and Mixed Strategies in Cyclic Competition
Physicists have been interested in the cyclic competition of species for quite some time. For the first part of my presentation I broadly introduce population dynamics, game theory, and pattern formation observed in spatial systems. I then present the results for when four species compete on different lattice structures. It is found that the probability distributions of the extinction times are non-trivial and contain more information than mean extinction times which are commonly reported in the literature. These non-trivial features have their origin in domain formation of both individual species and alliances and promote coexistence in the system. In the last part of my talk the agents are allowed to have mixed strategies and choose their strategy out of a distribution. This scheme for choosing strategies is not often seen in biology, however it does have applicabilities to economic systems such as the public goods game. This is simulated on a 1D lattice with three and four strategies and interesting patterns and stability properties are found depending on how discretized the choice of strategy of the agents is.
4:30 pm:
CM Journal Club in 326A Tate
Speaker: Jian Kang
Subject: Fractionalized Fermi Liquid for the Pseudogap Metal
The volume enclosed by Fermi surface in Brillouin zone is proportional to the sum of doped electron density and the localized moment density, as required by Luttinger theorem [1]. Experiments on underdoped cuprates suggest that the Fermi pocket volume is proportional to the doping in the pseudogap region. Fractionalized Fermi liquid is proposed as one candidate to explain its violation of Luttinger theorem [2] and Fermi arc observed by ARPES. In my presentation, I will briefly review the Luttinger theorem and recent experiments on pseudogap in cuprates. An effective theory on doped U(1) spin liquid [3] will be discussed in detail. If time allows, I will also present more recent numerical calculations with quantum dimer model [4].
[1] M. Oshikawa, Phys. Rev. Lett. 84, 3370 (1999).
[2] T. Senthil, S. Sachdev, and M. Vojta, Phys. Rev. Lett. 90, 216403 (2003).
[3] Y. Qi, and S. Sachdev, Phys. Rev. B 81, 115129 (2010).
[4] M. Punk, A. Allais, and S. Sachdev, arXiv:1501.000978.
Wednesday, February 11th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
Speaker: Jennifer Thomas, University College London
Subject: Neutrino Oscillations at Work
Refreshments served in Room 216 Physics after colloquium
The observation that the three types of neutrino flavor oscillate among themselves led to the realisation that neutrinos have a very small but non-zero mass. This is extremely important because the supremely successful Standard Model of particle physics had expected, and indeed needed, the neutrinos to have exactly zero mass. Since the discovery of neutrino oscillations over the last 15 years, the parameters of the oscillations have been sufficiently well measured to turn neutrino oscillations into a tool for learning more about the elusive neutrino. I will explain the concept of neutrino oscillations, and report on the recent results from around the world in context with the new challenges now facing researchers of inferring the remaining unknown neutrino properties. I will talk briefly about an exciting new project on the horizon for the very near future.
Faculty Host: Marvin Marshak
Thursday, February 12th 2015
Speaker: Larry Rudnick
Speaker: Yang Bai (U. Wisconsin)
Subject: Towards Understanding IceCube High Energy Neutrinos
The IceCube collaboration has recently observed high energy neutrinos in the 30 TeV to 2 PeV range. The flux is much above the atmospheric neutrino background and requires new sources to explain its origin. In this talk, I will provide a list of potential explanations with a focus on decaying dark matter and point-like sources.
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Ian Fisher, Stanford University
Subject: Probing electronic nematicity via elastoresistance measurements
In recent years, anisotropic electronic phases have been discovered in a variety of strongly correlated quantum materials. Borrowing language from the field of soft condensed matter physics, such phases are referred to as electronic nematic phases when they are driven by electron correlations and break a discrete rotational symmetry of the crystal lattice without further breaking translational symmetry. In this talk I'll outline a new technique that we have developed based on elastoresistance measurements, which probes an associated quantity, the nematic susceptibility. Measurements of this quantity directly reveal the presence of an electronic nematic phase transition in underdoped Fe-based superconductors, and an associated quantum phase transition near optimal doping (i.e. the doping that yields the maximum critical temperature of the superconductor). I'll explain the possible significance of this observation. I'll also discuss the case of ferroquadrupolar order in 4f intermetallic systems.
Faculty Host: Rafael Fernandes
Friday, February 13th 2015
11:30 am:
Speaker: Maciej Koch-Janusz, Weizmann Institute of Science
Subject: Two-dimensional Valence Bond Solid (AKLT) states from t_{2g} electrons
Two-dimensional AKLT model on a honeycomb lattice has been shown to be a universal resource for quantum computation. In this valence bond solid, however, the spin interactions involve higher powers of the Heisenberg coupling (S_i *S_j)^n, making these states seemingly unrealistic on bipartite lattices,
where one expects a simple antiferromagnetic order. We show that those interactions can be generated by orbital physics in multiorbital Mott insulators. We focus on t_{2g} electrons on the honeycomb lattice and propose a physical realization of the spin-3/2 AKLT state. We find a phase transition from the AKLT to the Neel state on increasing Hund's rule coupling, which is confirmed by density matrix renormalization group (DMRG) simulations. An experimental signature of the AKLT state consists of protected, free spins-1/2 on lattice vacancies, which may be detected in the spin susceptibility.
Speaker: Terry J. Jones, U Minnesota, MIfA
Subject: Probing the Earliest Stages of Massive Star Formation
Massive star formation is still poorly understood. These stars evolve quickly and have a profound effect on their immediate environment, yet they often form dense clusters of OB stars. Using SOFIA Mid-IR imaging, Hershel photometry, CSO Sub-mm polarimetry, and the GPIPS database, we explore the nature of massive star formation in the G034.43+00.24 Infrared Dark Cloud. In particular, we investigate a luminous Class 0 YSO (MM1), which is embedded in a very dense molecular cloud core thousands of visual magnitudes thick.
Speaker: Craig Hassel, Department of Food, Science and Nutrition, University of Minnesota
Subject: Spanning Cultural Difference in Food and Health
Refreshments served in Room 275 Nicholson Hall at 3:15 p.m.
I will explore examples of University outreach/cross-cultural engagement with older, non-biomedical thought systems (African, Chinese Medicine, Indigenous knowledge traditions) bringing profound cultural difference in epistemology and ontology. Spanning these chasms of cultural difference involves cognitive bridge-building, a form of community engaged scholarship wherein habitual attachment to familiar, self-affirming, biomedical mental models is relaxed, allowing for temporary dwelling within unfamiliar, and often unsettling assumptive terrain. Perseverance with such bridge-building creates novel cognitive locations and perceptual lenses through which to reconsider disciplinary issues of the day and to illuminate otherwise opaque cultural/disciplinary "hidden subjectivities" that too often escape conscious attention and peer review. I refer back to nutrition science with its positivist legacy, its history of success with deterministic, acute deficiency disease, and its current struggle with more complex diet-related chronic disease and concepts of well being. I propose that nutrition as a biomedical science would advance by learning and adapting discourses and/or thought styles akin to those within the humanities and/or social sciences.
Sponsored by the Minnesota Center for Philosophy of Science.
3:35 pm:
Speaker: Ken Heller, University of Minnesota
Subject: A Systems Approach to Teaching: Why the Introductory Physics Courses at Minnesota Work and How They Can Fail.
This seminar will be a discussion of the parts that go into the structure of the
introductory physics courses at the University of Minnesota. The design of these courses is based on empirical studies and general principles of cognitive science to fit the constraints and institutional goals of the University. We will discuss the goals of the course, the pedagogy employed and the impact of the structure on students, TAs, and faculty. Within this learning framework important considerations are the role of the faculty, TAs, and students and the purpose of lectures, laboratories, discussion sections, problems, and tests. We will also discuss how the outcomes of the course can be changed, for better or worse, and what changes cause it to fail.
Speaker: Dan Cronin-Hennessy, University of Minnesota
Subject: The mu2e Experiment
Monday, February 16th 2015
12:15 pm:
Speaker: Clement Pryke, University of Minnesota
Subject: Results from Joint analysis of BICEP2/Keck and Planck data
Tuesday, February 17th 2015
Speaker: Chris Conklin, University of Minnesota
Subject: To be announced.
To be announced.
1:25 pm:
Space Physics Seminar in 435 Physics
Speaker: Dr. Lindsay Glesener, Space Science Lab, UCBerkeley
Subject: Exploring the Sun at high energies: progress and new instrumentation
The Sun provides a nearby case study in which to study plasma processes and high-energy astrophysical phenomena with high-resolution remote sensing combined with in-situ data and even multiviewpoint measurements — tools that are not available to study any object outside the solar system. In addition to basic physics research interests, understanding high-energy aspects of the Sun also has practical applications, since Earth-directed solar eruptive events can pose a danger to satellites, astronauts, and power grids. New, direct-focusing techniques are now available to study solar flares and eruptions using hard X-rays. The first generation of solar-dedicated hard X-ray focusing optics has recently flown on suborbital missions (rockets and balloons). And from low-Earth orbit, the Nuclear Spectroscopic Array (NuSTAR), a direct-focusing instrument designed to look at the faintest objects outside the solar system, has also produced detailed hard X-ray images of the Sun. This seminar will cover recent advances in high-energy solar flare physics and will present new instrumentation, with emphasis on NuSTAR solar observations and on the FOXSI solar sounding rocket.
2:30 pm:
Biophysics Seminar in 210 Physics
There will be no seminar this week.
4:30 pm:
CM Journal Club in 236A Tate
Subject: There will be no seminar this week.
Wednesday, February 18th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
To be announced.
3:35 pm:
Speaker: Michel Janssen, University of Minnesota
Subject: The centenary of general relativity: How did Einstein find his gravitational field equations?
Refreshments served in Room 216 Physics after colloquium
In his search for gravitational field equations from late 1912 to late 1915, Einstein vacillated between two different strategies. Following a "mathematical strategy," he extracted candidate field equations from the Riemann curvature tensor and checked whether these equations were compatible with energy-momentum conservation and reproduced Newton’s theory of gravity in the appropriate limit. Following a "physical strategy," he constructed field equations for the gravitational field in close analogy with those for the electromagnetic field. In his later years, Einstein routinely claimed that he brought his search for gravitational field equations to a successful conclusion in November 1915 by switching to the mathematical strategy at the eleventh hour. Most commentators have accepted this later assessment but we have argued that Einstein achieved his breakthrough of November 1915 by doggedly pursuing the physical strategy. In a lecture in Vienna in September 1913, Einstein clearly laid out this physical strategy. As long as one took the older Einstein’s word for it that the mathematical strategy was responsible for the success of November 1915, one could quickly pass over the Vienna lecture. But if it was really the physical strategy that was responsible for this success, as we believe, the Vienna lecture deserves a much more prominent place in the account of the genesis of general relativity than it has been given so far.
Thursday, February 19th 2015
Speaker: Ryan Arneson
Speaker: Scott Davies, UCLA
Subject: Enhanced Cancellations and Ultraviolet Finiteness in Supergravity
In recent years, there has been much progress in understanding the ultraviolet properties of supergravity amplitudes. Through symmetry arguments and direct computations, supergravity has been found to be much tamer in the ultraviolet than previously thought. In this talk, I will discuss a new type of cancellation known as enhanced cancellation that renders a supergravity amplitude finite. Such cancellations cannot be understood through any symmetry argument based on a local covariant diagrammatic formalism. I will provide several examples where we observe enhanced cancellations, showing finiteness in supergravity amplitudes where naively divergence was expected. Understanding these enhanced cancellations through a means other than direct computation remains an open problem.
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Victor Gurare, University of Colorado - Boulder
Subject: Unconventional Anderson localization in high dimensions and Dirac materials
Hamiltonians describing particles moving in a random potential often have eigenstates which have finite spatial extend, a well-known phenomenon called Anderson localization. Above two dimensional space, localized wave functions all correspond to energies below a critical energy usually called the mobility edge. The size of the localized wave functions diverges as mobility edge is approached, a phenomenon called Anderson transition. It is generally believed that the details of Anderson transition depend on the dimensionality of space only, which is usually referred to as universality of the Anderson transition. We argue that in sufficiently high dimensions a second type of Anderson transition develops if the disorder strength is close to some critical value, distinct from the conventional transition, with a number of unusual features. For a conventional Schrodinger equation with a random potential one has to be above four dimensional space to see this new transition, thus it is not straightforward, although not impossible, to observe it. In electronic systems with a Dirac-like spectrum, one only has to be above two dimensions to observe this transition. We discuss the consequences of the existence of this transition for disordered materials with Dirac-like electronic spectra.
Faculty Host: Alex Kamenev
Friday, February 20th 2015
Speaker: Sally Oey, University of Michigan
Subject: The fate of ionizing radiation from massive stars in star-forming galaxies
The fate of ionizing radiation from massive stars has fundamental consequences on scales ranging from the physics of circumstellar disks to the ionization state of the entire universe. On galactic scales, the radiative feedback from massive stars is a major driver for the energetics and phase balance of the interstellar medium in star-forming galaxies. While even starburst galaxies appear to be largely optically thick in the Lyman continuum, ionization-parameter mapping shows that significant populations of HII regions within galaxies are optically thin, powering the diffuse, warm ionized medium. I will discuss our multi-faceted work to clarify our understanding of radiative feedback and diagnostics for probing LyC optical depth in star-forming galaxies from the Magellanic Clouds to starbursts.
Speaker: Amy Fisher, Science, Technology, and Society Program, University of Puget Sound
Subject: Hare's Calorimotor: Rethinking Thermodynamics in Early 19th-Century America
Refreshments served in Room 216 Physics at 3:15 p.m.
In the early nineteenth century, prominent chemists, such as Jons Jacob Berzelius and Humphry Davy, proclaimed that a revolution had occurred in chemistry through electrical science. Examining Robert Hare's contributions to this discourse, this presentation analyzes how chemists understood the relationship between heat and electricity during this transformative period. As an avid experimentalist, professor of chemistry at the University of Pennsylvania, and member of the American Philosophical Society, Hare actively shaped early American chemistry. He was part of a larger network of scholars, having corresponded with a number of scientists such as Joseph Henry, François Jean Arago, and Berzelius. He published works abroad in the Philosophical Magazine in England and the Annales de Chimie in France. He also experimented with and wrote extensively on electricity and its associated chemical and thermal effects. In particular, Hare's calorimotor – a device that utilized the voltaic pile (battery) and set caloric (or heat) into motion – raised important questions about Lavoisier's caloric theory of heat and its relationship to electricity.
3:35 pm:
Speaker: Miranda Pihlaja, University of Minnesota
Subject: College in Schools: The benefits, drawbacks, and challenges of implementation for physics
This talk will compare several college-credit programs available
to high school students including CIS, AP, IB, and PSEO. I will highlight
the benefits of the CIS program and discuss the challenges to
implementation. The benefits of the CIS program include high school
students being able to take courses in their school, not having the credit
based on one test at the end of the year, and receiving credit for a UMN
course instead of just elective credits. Challenges to implementation
include teacher selection, number of teachers in a cohort, establishing
essential and non-essential components of the courses, and teacher
evaluations. The two physics courses available through the CIS program are
PHYS1101W and PSTL1163.
Speaker: Vuk Mandic,University of Minnesota
Subject: Astrophysics and Cosmology with Gravitational Waves
Monday, February 23rd 2015
12:15 pm:
Speaker: Tom Jones, University of Minnesota
Subject: Cosmic Rays in Galaxy Clusters; Their Acceleration and Emissions
Contrary to previous calendar, there will be no MIFA Colloquium today.
Tuesday, February 24th 2015
APS Practice Talks
To be announced.
1:25 pm:
Space Physics Seminar in 435 Physics
Speaker: Marc Palupa, Space Sciences Laboratory, University of California-Berkeley
Subject: Measuring electrons in the solar wind: current status and future missions
Electrons are critical to the thermodynamics of the solar wind plasma. Due to their high mobility, they carry the majority of the heat flux in the solar wind. Electron beams can also be used as remote probes of the physics of shocks and solar flares. However, making accurate electron measurements is difficult: electrons are susceptible to spacecraft charging effects, and the non-thermal character of the electron distribution function limits the utility of plasma moment calculations. In this talk, I will present recent advances in precision measurements of solar wind electrons, and discuss their application to solar wind thermodynamics, shock acceleration of electrons, and electron heating associated with solar wind reconnection events. I will also discuss the measurement of electrons with particle and electric field instrumentation on the upcoming Solar Probe Plus mission.
2:30 pm:
Biophysics Seminar in 210 Physics
Speaker: Yiannis Kaznessis, Department of Chemical Engineering and Material Science
Subject: Multiscale models for antibiotic cellbots
Foodborne gastrointestinal infections are significant causes of morbidity and mortality worldwide. Alarmingly, because of the extensive, non-therapeutic use of antibiotics in agriculture, foodborne bacteria are emerging that are resistant to our most potent drugs.
We will discuss a novel approach to reduce the use of antibiotics in food-producing animals and to treat gastrointestinal infections. We engineer lactic acid bacteria (LAB) that express and release antimicrobial peptides (AMPs). LAB are part of the gastrointestinal microflora and can be safely delivered with known benefits to humans and animals. AMPs are proteins that can be readily produced by LAB. One unique aspect of our approach is the use of synthetic promoters that precisely regulate the delivery of AMP molecules.
At the heart of proposed efforts are multiscale models that guide explanations and predictions of the antagonistic activity of recombinant LAB against pathogenic strains. Models are developed to quantify how AMPs kill bacteria at distinct but tied scales. Using atomistic simulations the various interaction steps between peptides and cell membranes are explored. Mesoscopic models are developed to study ion transport and depolarization of membranes treated with AMPs. Stochastic kinetic models are developed to quantify the strength of synthetic promoters and AMPs expression. We will also present a closure scheme for chemical master equations, providing a solution to a problem that has remained open for over seventy years.1
Experimentally, we engineer lactic acid bacteria to inducibly produce antimicrobial peptides. We have used a library of synthetic biological constructs.2,3 We test these modified bacteria against pathogenic bacteria. We will present results against salmonella and enterococcus.4
1. Smadbeck P, Kaznessis YN. A closure scheme for chemical master equations. Proc Natl Acad Sci U S A. 2013 Aug 27;110(35):14261-5. doi: 10.1073/pnas.1306481110.
2. Ramalingam KI, Tomshine JR, Maynard JA, Kaznessis YN. Forward engineering of synthetic bio-logical AND gates, Biochemical Engineering, 47, 38-47, 2009.
3. Volzing K, Billiouris K, Kaznessis YN. proTeOn and proTeOff, New Protein Devices That Inducibly Activate Bacterial Gene Expression, ACS Chemical Biology, 6, 1107-1116, 2011.
4. Volzing K, Borrero J, Sadowsky MJ, Kaznessis YN. Antimicrobial Peptides Targeting Gramnegative Pathogens, Produced and Delivered by Lactic Acid Bacteria. ACS Synth Biol. 2013, 15;2(11):643-50. doi: 10.1021/sb4000367
Wednesday, February 25th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker: Chen Hou, University of Minnesota
Subject: The ODT Model And Its Applications On PRE bursts
A Type-I X-ray burst is the thermonuclear shell flash that happens on the surface of a neutron star. Studies on these bursts are of importance for understanding neutron stars in binary systems, nuclear reaction networks and dense matter at low temperature. I will discuss a subset of X-ray bursts that is powerful to lift up the photosphere with the simulations based on a new 1D turbulence model. The model is different in a sense that the turbulence is generated by a stochastic process and the stability of the system. The results will be compared with KEPLER's.
3:35 pm:
Speaker: Adam Cohen, Harvard University
Subject: Bringing Bioelectricity to Light
Refreshments served in Room 216 Physics after colloquium
In the wild, microbial rhodopsin proteins convert sunlight into biochemical signals in their host organisms. Some microbial rhodopsins convert sunlight into changes in membrane voltage. We engineered a microbial rhodopsin to run in reverse: to convert changes in membrane voltage into fluorescence signals that are readily detected in a microscope. Archaerhodopsin-derived voltage-indicating proteins enable optical mapping of bioelectric phenomena with unprecedented speed and sensitivity. We are applying these tools to study the role of voltage across biology: in bacteria, plant roots, fish hearts, mouse brains, and human induced pluripotent stem cell (hiPSC)-derived neurons and cardiomyocytes. We are engineering new functionality into microbial rhodopsins by taking advantage of their strong optical nonlinearities.
Faculty Host: Jochen Mueller
Thursday, February 26th 2015
Speaker: Soroush Sotoudeh and Evan Skillman
12:15 pm:
Speaker: Jesse Thaler (MIT)
Subject: What is Sudakov Safety?
For almost four decades, infrared and collinear (IRC) safety has been the guiding principle for determining which jet observables can be calculated using perturbative QCD. Now in the LHC era, new jet substructure observables have emerged which are IRC unsafe, yet still calculable using perturbative techniques. In this talk, I explain the origin of these "Sudakov safe" observables and show how they blur the boundary between perturbative and nonperturbative aspects of QCD.
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Brian Andersen, University of Copenhagen
Subject: Recent developments of cuprates and pnictides; pairing symmetry, competing order, and nematicity
In this talk I will present some of our recent theoretical efforts to understand the fascinating interplay between magnetic, charge, and superconducting order in cuprates and Fe-based superconductors. The talk will include a general discussion of spin fluctuations in iron pnictides, including the evidence and modelling of nematic (anisotropic) spin fluctuations. These can have profound influence on the transport properties of these systems both through inelastic scattering and emergent new static defect states significantly contributing to anisotropies in the measured quantities. This is true even above the magnetic transition where the anisotropic spin fluctuations can be frozen by disorder, to create elongated magnetic droplets whose anisotropy grows as the magnetic transition is approached. Such states act as strong anisotropic defect potentials that scatter with much higher probability perpendicular to their length than parallel, although the actual crystal symmetry breaking is tiny. From the calculated scattering potentials, relaxation rates, and conductivity in this region we conclude that such emergent defect states are essential for the transport anisotropy observed in experiments. I will end this part of the talk by presenting a general scenario for the transport anisotropy throughout the whole phase diagram.
Next, I will turn to a discussion of competing magnetic phases in the pnictides relevant to recent experiments finding magnetic order in a tetragonal crystal lattice. This points to the existence of other so-called C4 symmetric magnetic phases with, for example, non-collinear moments. I will present a theoretical microscopic study of these phases and their general electronic properties. A discussion will be included on the role of superconductivity and disorder in destroying and stabilizing these novel magnetic C4 states, respectively. Finally, if time allows, I will also discuss some recent studies of the doping dependence of the pairing symmetry of the cuprates in the presence of spin-density wave order.
Faculty Host: Rafael Fernandes
Friday, February 27th 2015
12:00 pm:
Condensed Matter Seminar in in Physics 435
Speaker: Paula Melado, School of Engineering and Applied Sciences, Adolfo Ibanez University, Santiago, Chile
Low-energy states of quantum spin liquids are thought to involve partons
living in a gauge-field background. We study the spectrum of Majorana
fermions of Kitaev's honeycomb model on spherical clusters. The gauge field
endows the partons with half-integer orbital angular momenta. As a consequence, the
multiplicities reflect not the point-group symmetries of the cluster, but
rather its projective symmetries, operations combining physical and gauge
transformations. The projective symmetry group of the ground state is the
double cover of the point group [1].
[1] Phys. Rev. B 91, 041103(R) (2015).
Faculty Host: Andrey Chubukov
Subject: High energy applications in Condensed matter: Non-Abelian vortices in superfluid $^3$He-B
In recent years, there has been a push to study condensed matter systems from the point of view of high energy physics and vice versa. On the one hand, studying condensed matter systems can give high energy theorists insight about the potential nature of the Planck vacuum. On the other hand, using techniques common to high energy theorists we can make new predictions about condensed matter systems. In this talk I present my research on the topic of vortices in the B phase of superfluid helium-3. Specifically, I discuss the appearance of non-Abelian zero modes on mass vortices in helium-3-like systems.
Speaker: Robert Lysak, Department of Physics and MIfA
Subject: Alfven Waves and the Aurora
The aurora is the visible manifestation of a electrical current system that couples the magnetosphere and ionosphere. This current system leads to the development of parallel electric fields that can accelerate the auroral particles. The "standard model" of auroral acceleration assumes that auroral particles are accelerated through a static potential drop associated with these fields. However, some auroral particle distributions do not conform to this scenario. Such distributions are thought to be accelerated through time-dependent parallel electric fields associated with Alfven waves, the analogue to waves on a string. These waves can be accompanied by parallel electric fields when the perpendicular scale size becomes small. There are two main regimes of this acceleration. At lower altitudes where the plasma is cold, electron inertial effects becomes important and can lead to the bulk acceleration of the cold plasma. At higher altitudes, the primary particle acceleration mechanism is Landau damping, which preferentially accelerates electrons with velocities near the Alfvén wave phase velocity. These mechanisms are favored in regions where there are sharp plasma gradients, such as at the plasma sheet boundary layer or on the edges of the auroral density cavity, since phase mixing is an efficient mechanism for reducing the perpendicular wavelength.
Speaker: Abena Dove Osseo-Asare, Department of History, University of Texas at Austin
Subject: From Plants to Pills: Take Bitter Roots for Malaria
Refreshments served in Room 216 Physics at 3:15 p.m.
How do plants become pharmaceuticals? In this talk, I examine the history of efforts to patent a treatment for malaria made from the bitter roots of fever vine (Cryptolepis sanguinolenta). Malaria is a serious health risk in tropical West Africa. In Ghana, where these bitter roots became known as "Ghana Quinine", a group of African scientists devoted their lives to creating a patented pharmaceutical from the plant. I consider their interactions with traditional healers from the 1940s, their struggles to establish a fledgling pharmaceutical industry, and the conflicts that complicated the success of the new drug in this postcolonial nation. This little known historical case provides a window into recent controversies surrounding biodiversity prospecting in tropical environments, the rights of indigenous peoples to shared benefits, and the quest for pharmaceutical patents. It is drawn from my recently published book, Bitter Roots: The Search for Healing Plants in Africa.
3:35 pm:
Speaker: Leon Hsu, University of Minnesota
Subject: Using the Cognitive Apprenticeship Framework to Inform and Shape Instruction in Physics
Of the many types of instruction that have been used throughout human history, the apprenticeship framework is one of the most successful and enduring and its imprint can be found in a wide variety of contexts, including the coaching of elite athletes, the training of professional musicians, and the education of physics graduate students. In this talk, I will discuss the idea of a "cognitive apprenticeship," which brings ideas from the apprenticeship framework into the academic arena, as well as how it has been used to design undergraduate physics instruction at the University of Minnesota.
Speaker: Ken Heller, University of Minnesota
Monday, March 2nd 2015
12:15 pm:
Speaker: Yong-Zhong Qian - University of Minnesota
Subject: Supernova Neutrinos and Nucleosynthesis: Implications for Chemical Evolution of Galaxies
I will review my recent works with various collaborators on nucleosynthesis by supernovae from progenitors of different masses and how this is affected by properties and interaction of neutrinos. Implications for chemical evolution of galaxies are discussed and an initial effort to build a model for individual dwarf galaxies is presented.
Tuesday, March 3rd 2015
There will be no sack lunch this week due to APS March Meeting
To be announced.
1:25 pm:
Space Physics Seminar in 435 Physics
Speaker: Lauren Blum, UC Berkeley, Space Sciences Laboratory
Subject: Investigating the dynamics of Earth’s radiation belts through new CubeSat measurements and conjunction studies
The Van Allen radiation belts, composed of energetic ions and electrons trapped around the Earth, often exhibit dramatic variations in intensity and spatial extent. Characterization of the processes contributing to electron acceleration and loss in this region is critical to understanding the variable near-Earth space environment. Here, we’ll investigate the contribution of electron precipitation into the atmosphere to radiation belt dynamics and losses. Through a combination of long-term existing data sets as well as recent CubeSat and balloon measurements, we exploring the nature and extent of electron loss to the atmosphere as well as what electromagnetic wave modes may be causing it. These studies aid in the understanding of outer radiation belt dynamics and the relationship between precipitating energetic electrons, electromagnetic waves, and global magnetospheric conditions. They also demonstrate how small inexpensive CubeSats can complement larger missions and significantly enhance their scientific return.
2:30 pm:
Biophysics Seminar in 210 Physics
There will be no seminar this week.
Wednesday, March 4th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker: Zhu Li, University of Minnesota
Subject: Study on Nucleosynthesis of Low Mass Supernovae
Low-mass ( 8-10 solar masses) supernovae (ECSNe) which result from the collapse of O-Ne-Mg cores triggered by electron capture could provide a source of elements heavier than iron. The yields of nucleosynthesis for a 8.8 solar mass ECSN was studied based on the hydrodynamic simulation with state-of-art treatment for neutrino transport. In terms of the yield relative to iron, this nucleosynthesis is dominated by Sc and Co, and is very different from that for a regular supernova (heavier than 10 solar masses). Further, some proton-rich nuclei could be synthesized in significant amounts even in ECSN ejecta with equal number of protons and neutrons. Neutrino interactions on light nuclei are observed to smooth the yields of heavy nuclei. These results are analyzed using the theory of quasi-equilibrium nucleosynthesis. Due to their relatively clear nucleosynthetic signatures, the contributions of ECSNe could be inferred from the abundances in some extremely metal-poor stars with high [Sc/Fe] and [Co/Fe].
3:35 pm:
There will be no Colloquium this week.
Thursday, March 5th 2015
Speaker: Evan Nuckolls and Liliya Williams
Speaker: Marco Bochicchio (INFN, Rome)
Subject: An asymptotic solution of large-N QCD, and of large-N n=1 SUSY YM
We find an asymptotic solution for two-, three- and multi-point correlators of local gauge-invariant operators, in a lower-spin sector of massless large-N QCD (and of n=1 SUSY YM), in terms of glueball and meson propagators, in such a way that the solution is asymptotic in the ultraviolet to renormalization-group improved perturbation theory, by means of a new purely field-theoretical technique that we call the asymptotically-free bootstrap, based on a recently-proved asymptotic structure theorem for two-point correlators. The asymptotically-free bootstrap provides as well asymptotic S-matrix amplitudes in terms of glueball and meson propagators. Remarkably, the asymptotic S-matrix depends only on the unknown particle spectrum, but not on the anomalous dimensions, as a consequence of the LSZ reduction formulae. Very many physics consequences follow, both practically and theoretically. In fact, the symptotic solution sets the strongest constraints on any actual solution of large-N QCD (and of n=1 SUSY YM), and in particular on any string solution.
1:25 pm:
Condensed Matter Seminar in 210 Physics
There will be no seminar this week due to APS March Meeting
Friday, March 6th 2015
11:00 am:
Special Space Physics Seminar in 435 Tate Lab of Physics
Speaker: Lois Sarno-Smith, University of Michigan
Subject: High Energy" Ion depletion in the Post-Midnight Plasmasphere - Using the Van Allen Probes Satellite Suite to Uncover Mysteries of the Inner Magnetosphere
Using the Helium Oxygen Proton Electron (HOPE) instrument, Electric Fields and Waves (EFW), and the Electric and Magnetic Field Instrument Suite (EMFISIS) instruments, we examine how combining multiple instruments that characterize plasma can enable us to under how the 1-10 eV ion population, where the bulk of the plasmasphere lies, experiences strong local time asymmetry.
Speaker: Charles Steinhardt, IPAC
Subject: Are All Galaxies the Same? A Synchronized, Uniform Framework for Galaxy and Black Hole Evolution
Initial results from SPLASH, an ultra-deep multi-wavelength survey, allow a study of star formation out to z~6. Combining these results with dozens of star formation and supermassive black hole accretion studies, there is a consistent picture of galactic evolution at 0 < z < 6. These results also create tension with hierarchical merging at high redshift. We can define a "synchronization timescale" for galaxies as a measure of the uniformity of an ensemble of galaxies at various cosmic epochs. If galaxy evolution is dominated by stochastic processes, then galactic events occurring at high redshift should happen at nearly the same time across an ensemble of galaxies, while events occurring at low redshift should be much less synchronous. Surprisingly, this
synchronization timescale is both mass- and time-independent, a constant 1.4 Gyr for all combinations of mass and time. As a result, we are prompted to consider a framework for galactic evolution along a main sequence so that star formation, supermassive black hole accretion, and feedback between the two are dominated by deterministic rather than stochastic processes.
Speaker: Andrea Woody, Department of Philosophy, University of Washington
Subject: A Methodological Role for Explanation in Science: Mechanistic Explanation and the Functional Perspective
Refreshments served in Room 275 Nicholson Hall at 3:15 p.m.
Philosophy of science offers a rich lineage of analysis concerning the nature of scientific explanation. The vast majority of this work, aiming to articulate necessary and/or sufficient conditions for explanations, presumes the proper analytic focus rests at the level of individual explanations. In recent work I have been developing an alternative, which I call the functional perspective, that shifts focus away from explanations as individual achievements and towards explaining as a coordinated activity of communities.
In this talk, I outline the functional perspective and discuss certain virtues and challenges for the framework. In particular, the functional perspective suggests that explanatory discourse should be “tuned” to the epistemic and practical goals of particular scientific communities. To explore the plausibility of this contention, I examine explanatory patterns involving reaction mechanisms in organic chemistry. The aim here is to investigate ways in which such explanations are shaped to support the largely synthetic goals of the discipline. The contrast case will be mechanistic explanations in the biological sciences as recently characterized by philosophers of science. Mechanistic explanations in chemistry seem different in important respects. Most basically, I will argue that this example illustrates how taking the functional perspective may reveal an important methodological role for explanation in science, a role situated ultimately in social epistemology.
Sponsored by the Minnesota Center for Philosophy of Science
3:35 pm:
Speaker: Peter Bohacek, Sibley Senior High
Subject: Using Generation-2 Direct Measurement Videos for student inquiry
New Direct Measurement Videos allow students to vary parameters, and to select and position measurement tools. For example, a Gen-2 DMV allows students to vary the constant force on a cart to measure the resulting acceleration. Students can plot the relationship between force and acceleration. With these new tools, students can make decisions about how best to analyze the situation.
I'll show examples of how this has been implemented in my classroom, and on the MIT and BU physics MOOCs, and discuss preliminary results from last summer's AB testing in the MIT MOOC.
I'll also discuss how students can use DMVs and measurement uncertainty to explore the limits of the simplified models.
Speaker: Boris Shklovskii, University of Minnesota
Subject: To be announced.
Monday, March 9th 2015
12:15 pm:
Speaker: Marco Peloso, University of Minnesota
Subject: A particle physics model for inflation and the baryon asymmetry of the universe
Motivated by the coincidence between the Hubble scale during inflation and the typical see-saw neutrino mass scale, we present a supergravity model where the inflaton is identified with a linear combination of right-handed sneutrino fields. The model accommodates an inflaton potential that is flatter than quadratic chaotic inflation, resulting in a measurable but not yet ruled out tensor-to-scalar ratio. The evolution of the sneutrino fields after inflation carries a lepton charge that can be the origin of the observed baryon asymmetry of the universe. This talk is based on the preprint arXiv:1501.06560
Tuesday, March 10th 2015
Speaker: Yangmu Li, UMN
Subject: To be announced.
To be announced.
1:25 pm:
Space Physics Seminar in 210 Physics
Speaker: Sabrina Savage, NASA Marshall Space Flight Center
Subject: Solar Flares
The Earth is bathed in the atmosphere of our nearest stellar neighbor. Therefore, events occuring on the Sun's surface directly affect us by interfering with satellite operations and communications, astronaut safety, and, in extreme circumstances, power grid stability. Solar flares are a substantial source of hazardous space weather affecting our increasingly technology-dependent society and are the most energetic events in our solar system. Ground-based telescopes have been providing flare observations for over 150 years, but we now live in an era when modern space-bourne observatories provide us with even more stunning visualizations of twisted plasma escaping the Sun's surface. At the same time, these instruments give us the tools necessary to explore the physical mechanisms behind such enormous displays of energy release like never before. With nearly continuous multi-wavelength flare coverage, we can now probe the origins and evolution of flares by tracking particle acceleration, changes in ionized plasma, and the reorganization of magnetic fields. I will present some details behind flare mechanics, particularly magnetic reconnection which is a ubiquitous form of energy release throughout the cosmos, and how they affect the Earth while showing several examples of these truly fantastic explosions.
2:30 pm:
Biophysics Seminar in 210 Physics
There will be no seminar this week.
4:30 pm:
Special Condensed Matter Seminar in 435 Tate Lab of Physics
Speaker: Alexander Tsirlin, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
Subject: Unconventional ferrimagnetism driven by the magnetic anisotropy on the kagome lattice
The majority of ferrimagnets comprise nonequivalent spin sublattices that produce a net moment, which is an integer fraction of the magnetic moment on one site. We elaborate on an alternative mechanism that yields ferrimagnets with arbitrary net moments produced by a spin canting. This canting originates from the frustration of the spin-1/2 kagome lattice with ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor couplings, as in the francisite mineral Cu_3 Bi(SeO_3)_2 Cl and its synthetic sibling compounds.
Classical treatment of the francisite spin model with only isotropic (Heisenberg) interactions leads to an infinitely degenerate ground state, where both ferrimagnetic (canted) and antiferromagnetic (spiral) phases have equal energies. Quantum corrections explored by the coupled-cluster method result in a marginal stabilization of the ferrimagnetic state. However, the main driving force behind the unconventional ferrimagnetism turns out to be the magnetic anisotropy of Dzyaloshinsky-Moriya (DM) type. By evaluating both isotropic and anisotropic (DM) terms in the spin Hamiltonian from first-principles DFT calculations, we establish a complete microscopic magnetic model of francisites and compare it to the experiment.
The opportunities for calculating isotropic exchange couplings and magnetic anisotropy parameters from DFT will be discussed.
Wednesday, March 11th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker: Zhen Yuan, University of Minnesota
Subject: Chemical Evolution Model of Fornax Spheroidal Dwarf Galaxy
Observations strongly indicate that chemical enrichment in nearby dwarf spheroidal galaxies (dSphs) remains inhomogeneous until the end of their star formation despite their small size. Motivated by this unsolved problem, I built a chemical evolution model for Fornax, the brightest dSph in Milky Way, based on its star formation history. I simulated stochastic and inhomogeneous mixing of newly-synthesized elements by supernovae and compared the results with the observed metallicity distributions and scatter in abundances of individual elements of e.g., Mg, Si, Ca, Ti, and Fe. This approach not only can test supernova nucleosynthesis models, but also provides insights into mixing of supernova ejecta with the interstellar medium. I found that this mixing depends on large-scale gas flows, and the differences between environments of core-collapse and Type Ia supernovae.
3:35 pm:
Speaker: Philip Schuster, Perimeter Institute for Theoretical Physics
Subject: Accelerating our Understanding of Dark Matter
Refreshments served in Room 216 Physics after colloquium
Most of the matter in the Universe is dark; determining the composition and interactions of this dark matter are among the defining challenges in particle physics today. I will summarize the present status of dark matter searches and the case for exploration beyond the WIMP paradigm, particularly the motivations for “light dark matter” close to but beneath the weak scale. I will also describe sharp milestones in sensitivity needed to decisively explore the best-motivated light dark matter scenarios, and comment on experimental techniques to reach these milestones.
Faculty Host: Priscilla Cushman
Thursday, March 12th 2015
Speaker: Chris Nolting and Robert Lysak
Speaker: Marc Sher, College of William & Mary
Subject: The Instability of the Standard Model Vacuum
With the discovery of the Higgs boson in 2012, the basic parameters of the Standard Model are known. At large scales of O(10^11 GeV), the quartic coupling constant of the Higgs potential becomes negative, leading to the Standard Model vacuum being metastable. Calculations of the decay rate show that the present vacuum will live much longer than the age of the Universe. I will review the features of the effective Higgs potential that lead to the instability and describe how to calculate the decay rate. I will then show that Planck scale operators, which one might naively expect to be negligible given that the instability scale is of factor of 10^8 below the Planck scale, in fact can have dramatic changes on the decay rate.
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Ioannis Rousochatzakis, UMN
Subject: Multiscale theory of Cu2OSeO3: helimagnetism, skyrmions, and beyond
Friday, March 13th 2015
08:00 am:
Untitled in Physics
Speaker: Ed Loh, Michigan State
Subject: Molecular hydrogen knots in the Crab Nebula--New light on an old subject
We discovered 55 knots of molecular hydrogen in the Crab Nebula. What does this new component tell us? The H2 knots are associated with a cooler population of the well-known filaments, and strangely 80% are on the back side of the nebula. The temperature of the H2 emission is 2500-3000K. We have images and spectra from the SOAR Telescope and images from HST; we have new spectra from the Large Binocular Telescope.
There will be no colloquium this week.
3:35 pm:
There will be no seminar this week.
Speaker: Dan Dahlberg, University of Minnesota
Subject: Low Frequency Noise in Mesoscopic Magnetic Dots
Measurements of random telegraph noise (RTN) in individual mesoscopic sized NiFe alloy dots will be presented; the dots dimensions are as small as 200nm x 200nm x 10nm [Appl. Phys. Lett. 104, 252408 (2014)]. The temperature and magnetic field dependence of the RTN are explained by the energy landscape in the dots; the energy landscape RTN was independently measured [Appl. Phys. Lett. 103, 042409 (2013)]. The research was motivated by questions raised in understanding magnetic noise in magnetic tunnel junctions and giant magnetoresistance devices [Appl. Phys. Lett. 95, 062512 (2009) and Phys. Rev. B 88, 014409 (2013)].
Monday, March 16th 2015
08:00 am:
Tuesday, March 17th 2015
08:00 am:
There will be no seminar this week.
1:25 pm:
Space Physics Seminar in 210 Physics
There will be no seminar this week.
1:25 pm:
Speaker: John Ellis, CERN
Subject: Future circular colliders
Faculty Host: Keith Olive
2:30 pm:
Biophysics Seminar in 210 Physics
There will be no seminar this week.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Morten Holm Christensen
Subject: Effect of Hund's coupling on Mott physics in multi-band systems
I will begin with a brief review of Mott physics in the one-band case. After having introduced the necessary terminology I introduce a general multi-band model and argue that, due to the presence of the Hund's coupling in such a model, the system can undergo a so-called orbital-selective Mott transition [1]. Subsequently, I highlight the substantial differences between the half-filled case and the non-half-filled case [2]. Finally I will discuss the possible manifestation of this transition in the iron-chalcogenides [3].
[1] L. de' Medici et al. Phys. Rev. Lett. 102, 126401 (2009).
[2] L. de' Medici, Phys. Rev. B. 83, 205112 (2011).
[3] Z. Xu et al. Phys. Rev. B. 84 052506 (2011).
Wednesday, March 18th 2015
08:00 am:
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
Subject: Spring Break - No colloquium
Refreshments served in Room 216 Physics after colloquium
Thursday, March 19th 2015
08:00 am:
Speaker: No Seminar, SPRING BREAK
1:25 pm:
Speaker: Eugene Levin, Iowa State
Subject: Recent findings for the Seebeck effect in thermoelectric tellurides
The Seebeck effect, known since 1821 and utilizing in thermoelectric materials to convert thermal to electrical energy, have been intensively studied and used in various applications, but there are indications that its fundamental understanding is still lacking. In order to better understand the Seebeck effect, we have used tellurides as model systems, common experimental methods (XRD, Seebeck coefficient, electrical resistivity, Hall effect, thermal conductivity, SEM, and EDS), and advanced method (125Te NMR to obtain the carrier concentration in tellurides via spin-lattice relaxation measurements). Several intriguing relations between the Seebeck coefficient, carrier concentration, composition, and rhombohedral lattice distortion have been established for GeTe alloyed with Ag and Sb (well-known high thermoelectric efficiency TAGS-m series). The Seebeck coefficient in some tellurides can be described by a common model with energy independent carrier scattering, but in some not. The latter can be explained by the effect from additional mechanism, likely energy filtering produced by [Ag+Sb] pairs in GeTe matrix. Our findings demonstrate that the Seebeck effect still holds surprises, and innovative research in the area of thermoelectric materials may help to elucidate and better utilize thermoelectric phenomena.
Faculty Host: Boris Shklovskii
Speaker: No Journal Club - Spring Break
Friday, March 20th 2015
08:00 am:
Speaker: No colloquium - Spring Break
There will be no colloquium this week.
3:35 pm:
There will be no seminar this week.
There will be no seminar this week.
Monday, March 23rd 2015
12:15 pm:
Speaker: Karl Young - University of Minnesota
Subject: The assembly of 'normal' galaxies at z~7 probed by ALMA
I will discuss a recent paper on ALMA observations of 3 high z galaxies, 6.8 < z < 7.1, searching for [CII] emission. Detected [CII] emission is interpreted as arising from accreting clumps of neutral gas, showing galactic assembly at z~7. I will discuss their observations, results, and simulations.
The paper, arXiv:1502.06634
Tuesday, March 24th 2015
Speaker: Chun Chen, UMN
Subject: Splitting the topological ground-state degeneracy of parafermions in fractional quantum Hall heterostructures
12:20 pm:
Space Physics Seminar in 210 Physics
There will be no seminar this week.
To be announced.
2:30 pm:
Biophysics Seminar in 210 Physics
There will be no seminar this week.
4:30 pm:
CM Journal Club in 236A Tate
There will be no seminar this week.
Wednesday, March 25th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
Speaker: Allan MacDonald, University of Texas, Austin
Subject: Exciton Condensates are Super!
Refreshments served in Room 216 Physics after colloquium
Electronic systems can have a type of order in which coherence is spontaneously established between two distinct groups of electrons. So far this (particle-hole or exciton condensate) type of order has been found only in double-layer two-dimensional electron gas systems, and only in certain strong magnetic field limits. I will review some of the surprising superfluid transport effects that have been observed in double-layer exciton condensates, and speculate on the possibility of realizing similar effects at room temperature either by enhancing the stability of bilayer exciton condensate states or by designing ferromagnetic materials with appropriate properties.
Faculty Host: Alex Kamenev
Thursday, March 26th 2015
Speaker: Taryn Heilman and Amit Kashi
12:15 pm:
Speaker: Clay Córdova (Harvard)
Subject: TBA
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Michael Schuett, University of Minnesota
Subject: Electronically-induced resistivity anisotropy in underdoped cuprates and iron pnictides
Friday, March 27th 2015
Speaker: Brant Robertson, U Arizona
Subject: New Constraints on Cosmic Reionization from Planck and Hubble Space Telescope
Understanding cosmic reionization requires the identification and characterization of early sources of hydrogen-ionizing photons. The 2012 Hubble Ultra Deep Field (UDF12) campaign has acquired the deepest blank-field infrared images with the Wide Field Camera 3 aboard Hubble Space Telescope and, for the first time, systematically explored the galaxy population deep into the era when cosmic microwave background (CMB) data indicates reionization was underway. The UDF12 campaign thus provides the best constraints to date on the abundance, luminosity distribution, and spectral properties of early star-forming galaxies. We synthesize the UDF12 results with results from other HST campaigns and the most recent constraints from Planck CMB observations to infer redshift-dependent ultraviolet luminosity densities, reionization histories, and electron scattering optical depth evolution consistent with the available data. We review these results, and discuss future avenues for progress in understanding the epoch of reionization.
Speaker: Kristin Peterson, Department of Anthropology, University of California, Irvine
Subject: Transcontinental Drug Traffic: Chemical Arbitrage, Speculative Capital, and Pharmaceutical Markets in Nigeria
Refreshments served in Room 216 Physics at 3:15 p.m.
In the 1970s, Nigeria's oil boom generated unprecedented state wealth, quite in contrast to a massive U.S. economic recession. During that period, U.S. and European multinational companies turned to Nigeria to manufacture drugs and sold them on what was then a significant and important foreign market in terms of sales. By the 1990s, brand name drug markets in Nigeria and throughout Africa were completely eviscerated and relocated elsewhere. What was once almost exclusively a brand name drug market is now home to mostly imported pharmaceuticals throughout the world, for which there are constant concerns over drug quality. The paper first discusses two simultaneous convergences that remade the West African brand name market: Nigeria's structural adjustment program and the pharmaceutical industry's turn to speculative capital. It then provides an overview of the kinds of markets and the kinds of drugs that emerged in the aftermath of brand name industry's abandonment of the West African market. It concludes with a discussion on how actors within Nigerian and global drug markets interact with chronic, and indeed anticipated, market volatility in ways that produce new orders of pharmaceutical value.
3:35 pm:
Speaker: Julie Vievering, University of Minnesota
Subject: Reimagining the Physics TA: A Deeper Look Into the Essential Role of Coach
In this seminar, I will discuss the role of a TA in the Minnesota Model for teaching physics from my perspective as both a TA for the intro physics courses and a mentor to the new graduate and undergraduate TAs. In addition, this session will explore the learning theories which connect to the coaching methods used by TAs, contrasting these methods with more traditional ones, and highlight the opportunities that the structure of our discussions/labs creates for our students. Finally, after noting the pedagogical benefits of the ideal form of the model and the importance of the TA in facilitating the learning process, we will discuss the challenges that physics TAs in our department often face, and explore possible remedies.
Speaker: Jeremiah Mans, University of Minnesota
Subject: To be announced.
Monday, March 30th 2015
12:15 pm:
Speaker: Tova Yoast Hull, University of Wisconsin
Subject: Cosmic Ray Interactions: Implications for Nearby Starbursts
M82, NGC 253, and Arp 220 are often associated with each other due to similarities in the intense starburst environments contained within each galaxy. Dense concentrations of young massive stars, strong magnetic fields, and high radiation fields characterize their starburst nuclei. Additionally, both M82 and NGC 253 have been detected in gamma-rays with Fermi. Despite their similarities, the interstellar medium and effects of galactic winds differ in these galaxies. These distinctions are vital to understanding the cosmic ray populations and how their interactions produce the observed radio and gamma-ray spectra from each galaxy. I will discuss results of my single-zone models of the cosmic ray populations of the starburst nuclei and their implications for future gamma-ray and neutrino observations.
Speaker: Greg Fuchs, Cornell
Subject: Coherent control over diamond nitrogen-vacancy center spins with a mechanical resonator (and other recent results)
Tuesday, March 31st 2015
Speaker: Gordon Stecklein, UMN
Subject: Spin Transport in CVD Graphene Using Co/AlOx contacts
To be announced.
1:25 pm:
Space Physics Seminar in 210 Physics
Speaker: Cindy Cattell, University of Minnesota
Subject: Location of excitation of whistler-mode waves during geomagnetic storms: van Allen Probes observations of unusually low frequency chorus
2:30 pm:
Biophysics Seminar in 210 Physics
There will be no seminar this week.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Brent Perreault
Subject: Classifying Fractionalization
Fractionalization is a property of both topological phases and spin liquids. Moreover, in many cases it may be the easiest characteristic to use to identify these systems in experiments. I will talk about recent work in classifying the way that symmetry acts on fractional quasiparticles [1]. I will introduce the classification scheme and discuss the measurable signatures in relation to exactly solvable examples such as Kitaev’s Toric Code model [2]. (Recent applications are [3] and [4]).
[1] “Classifying fractionalization,” Essin and Hermele, PRB 87, 104406 (2013)
[2] “Spectroscopic signatures of crystal momentum fractionalization,” Essin and Hermele, PRB 90, 121102(R) (2014)
[3] “Numerical detection of symmetry-enriched topological phases with space-group symmetry,“ Wang, Essin, Hermele, and Motrunich: PRB 91, 121103(R) (2015)
[4] “Detecting crystal symmetry fractionalization from the ground state: Application to Z2 spin liquids on the kagome lattice,“ Qi and Fu, PRB 91, 100401(R) (2015)
Wednesday, April 1st 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker: Projjwal Banerjee (U. Minnesota)
Subject: Origin of Short-Lived Isotopes in the Early Solar System
Understanding the origin of the short-lived radio isotopes (SLR) that were present in the early solar system (ESS) is crucial in understanding the events leading to the formation of the Solar System. Many of the SLR require a nucleosynthetic event within about a million years before the formation of the Solar System. We show that low mass compact progenitors of can self-consistently account of some of the very short-lived isotopes such as ^{41} Ca, ^{53} Mn, and ^{60} Fe. Furthermore, neutrino-induced spallation can also account for ^{10} Be in the ESS, which until now were thought to be produced only by cosmic ray irradiation.
3:35 pm:
Speaker: Laura Greene, University of Illinois at Urbana-Champaign
Subject: Deciphering Electron Matter in Unconventional Superconductors
Refreshments served in Room 216 Physics after colloquium
Superconductors may be grouped into two major classes. The first is conventional metallic, whose pairing mechanism is explained by the BCS theory and electron-phonon coupling. The second we call unconventional, and the precise pairing mechanism has still to be worked out. All of the unconventional superconductors have electronic properties that are highly tunable, either by doping or pressure, from a non-superconducting parent compound, to a superconductor, to a non-superconducting Fermi liquid, thus defining a superconducting ‘dome’ in the phase diagram. More than 40 families of such materials, including the high-temperature superconductors, exhibit this ubiquitous phase diagram. In the underdoped phases, all of these materials show intriguing correlated electron states above the dome, and researches agree that the understanding of this “electron matter” holds the key to the pairing mechanism. Finally, I will show how we have found that point contact spectroscopy is exquisitely sensitive detecting electron matter.
Faculty Host: Rafael Fernandes
Thursday, April 2nd 2015
Speaker: Mehdi Lame'e
12:15 pm:
Speaker: Chris Brust (Perimeter Institute)
Subject: Resurgent SUSY, Accidental SUSY and String Theory
I will discuss the mechanism of accidental SUSY, the notion of having non-supersymmetric RG flows ending on supersymmetric fixed points, from the point of view of QFT, RS and string theory. I will also discuss the mechanism's utility in BSM model building, specifically as a way of UV-completing natural SUSY in the model of "resurgent SUSY", solving both the little and big hierarchy problems. I will argue that a Z2 orbifold of the Klebanov-Strassler solution exhibits accidental SUSY, and furthermore is a prototype for the strong sector that should be present in resurgent SUSY.
1:25 pm:
Condensed Matter Seminar in 210 Physics
Speaker: James Analytis, UC Berkeley
Subject: Magnetoresistance near a quantum critical point
The physics of quantum critical phase transitions connects to some of the most difficult problems in condensed matter physics, including metal-insulator transitions, frustrated magnetism and high temperature superconductivity.
Near a quantum critical point(QCP)a new kind of metal emerges, whose thermodynamic and transport properties do not fit into the unified phenomenology with which we understand conventional metals - the
Landau Fermi liquid(FL)theory - characterized by a low temperature limiting T-linear specific heat and a T^2 resistivity.Studying the evolution of the T dependence of these observables as a function of a control parameter leads to the identification both of the presence and the nature
of the quantum phase transition in candidate systems. In this study we measure the transport properties of BaFe2(As1-xPx)2,at T by suppressing superconductivity with high magnetic fields. We find an anomalous magnetic field dependence that suggests that not only does magnetic field directly affect the scattering rate (which is unusual for metals), but it does so in a way that is identical to temperature. We suggest that there is a universal phenomenology of scattering near a quantum critical point.
Faculty Host: Andrey Chubukov
Friday, April 3rd 2015
12:00 pm:
Condensed Matter Seminar in Physics 435
Speaker: Dmitrii Maslov, University of Florida
Subject: "Transport in strongly correlated electron systems"
Faculty Host: Andrey Chubukov
Speaker: Pavel Bolokhov, Premiere Institute
Subject: Low-Energy Effective Action of CP(N-1) Model at large N
We provide a solution for the supersymmetric CP(N-1) at large N
written in superfields. Specifically, we find the Kahler potential of
the model by supersymmetrizing the known results for the effective
potential of the theory. We also generalize the problem by introducing
twisted masses, and by breaking supersymmetry to N=(0,2). Such
theories arise as effective models on the heterotic vortex strings.
Speaker: Kris Davidson, MIfA
Subject: The Great Impostor Trying to Recover
Speaker: Gabriela Soto Laveaga, Department of History, University of California, Santa Barbara
Subject: Rural Health and Striking Urban Doctors: The Aftermath of Mexico's Attempt to Provide Healthcare for All
Refreshments served in Room 216 Physics at 3:15 p.m.
In late 1964 residents and interns walked out of Mexico City hospitals and clinics in what would become a ten-month-long medical movement. In the months that followed the walkout, young doctors' demands shifted from salary and better working conditions to openly questioning an increasingly oppressive regime. Mexico had long been seen as a leader in health care delivery in Latin America and the image of doctors protesting in the streets became a visible sign of the failings of the nation's public health care system. This presentation examines the unlikely aftermath of the medical movement as well as its causes and links to earlier policies to provide healthcare to rural Mexicans.
3:35 pm:
There will be no seminar this week.
Speaker: Bob Lysak, University of Minnesota
Monday, April 6th 2015
12:15 pm:
Speaker: Jason Evans, University of Minnesota
Subject: The Moduli and Gravitino (non)-Problems in Models with Strongly Stabilized Moduli
Tuesday, April 7th 2015
08:00 am:
Untitled in Physics
Speaker: Xiaoyu Wang, University of Minnesota
Subject: Probing quantum critical pairing in the iron-based superconductors: a Quantum Monte Carlo study
12:20 pm:
Space Physics Seminar in 210 Physics
Speaker: Dr. Matthew Broughton, Dartmouth University
Ground and Space Observations of Auroral Medium Frequency Radio Emissions
To be announced.
2:30 pm:
Biophysics Seminar in 110 PAN
Speaker: Jasmine Foo, School of Mathematics, University of Minnesota
Subject: Evolutionary dynamics in spatially structured populations
In this talk I will present results on a model of spatial evolution on a lattice, motivated by the process of carcinogenesis from healthy epithelial tissue. Cancer often arises through a sequence of genetic alterations. Each of these alterations may confer a fitness advantage to the cell, resulting in a clonal expansion. To model this we will consider a generalization of the biased voter process which incorporates successive mutations modulating fitness, which is interpreted as the bias in the classical process. Under this model we will investigate questions regarding the rate of spread and accumulation of mutations, and study the dynamics of spatial heterogeneity in these evolving populations.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Tianbai Cui
Subject: Majorana modes in solid-state systems
The concept of ‘Majorana fermions’, first proposed by Ettore Majorana that spin-1/2 particles could be their own antiparticles, is ubiquitous in modern physics nowadays. Majorana’s big idea was supposed to be solely relevant to high energy physics like neutrino, dark matter and supersymmetry. But now, his conjecture can not only be fulfilled in solid-state systems but also bring a promising future to the quantum information processing. In this talk, I will first introduce the historical background of Majorana fermions. Then I will bring the Majorana physics to solid-state systems by introducing two toy models that support Majorana modes. First is the Kitaev’s toy lattice model for 1D p-wave superconductor and the second is Fu-Kane model for 2D p+ip superconductor. Finally I will discussion the non-Abelian exchange statistics associated with the Majorana modes and their potential for quantum information processing.
Reference:
[1] J. Alicea, Reports on Progress in Physics, vol. 75, p. 076501, 2012.
[2] S. R. Elliott and M. Franz, Reviews of Modern Physics, vol. 87, pp. 137-163, 02/11/2015.
[3] A. Y. Kitaev, Physics-Uspekhi, vol. 44, p. 131, 2001.
[4] J. Alicea, Y. Oreg, G. Refael, F. von Oppen, and M. P. Fisher, Nature Physics, vol. 7, pp. 412-417, 2011.
Wednesday, April 8th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
Speaker: Steven Kivelson, Stanford University
Subject: Quenched disorder and vestigial nematicity in correlated electronic systems
Refreshments served in Room 216 Physics after colloquium
Intermediate phases with “vestigial order” occur when the spontaneously broken symmetries of a “fully ordered” groundstate are restored sequentially as a function of increasingly strong thermal or quantum fluctuations, or of increasing magnitude of quenched randomness. From this perspective, a large number of developments in the field of highly correlated systems – in particular the remarkable proliferation of cases in which electron nematic phases and their relatives appear as significant players in the physics of “interesting” materials - can be treated as variations on the same underlying theme. Recent experiments probing charge order in the pseudo-gap regime of the hole-doped cuprate high-temperature superconductors and nematic order in the Fe based superconductors are interpreted in light of these results.
Faculty Host: Rafael Fernandes
Thursday, April 9th 2015
Speaker: Matt Gomer
12:15 pm:
Speaker: David McGady (Princeton)
Subject: Constructing massless S-matrices
I will discuss several aspects of modern treatments of the on-shell S-matrix. In particular, I will give an inductive proof of on-shell recursion relations --- due to Britto, Cachazo, Feng, and Witten (BCFW) --- to graviton amplitudes in four dimensions. Unlike previous proofs of applicability in the literature, this proof relies exclusively on on-shell reasoning. As a corollary of this analysis, we show that the formerly mysterious bonus'' scaling of graviton amplitudes under large BCFW-shifts follows simply from Bose symmetry. I will also discuss a way to extract many beautiful, classic, no-go theorems from straightforward analysis of four-point scattering amplitudes.
1:15 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Steve Kivelson, Stanford University
Subject: Enhancement of superconductivity near a nematic quantum critical point
Please note: change of time for seminar, in effect for rest of semester.
Two topics that have attracted intense theoretical study over the past decade are the nature of quantum critical phenomena in metallic systems and what, if anything, such critical points have to do with an unconventional mechanism of superconducting pairing. The still un-mastered subtleties of the first problem have precluded convincing resolution of the second. For the model problem of a weakly interacting metal in proximity to a nematic quantum critical point (NQCP), we identify a broad regime of parameters in which the nature of the induced superconductivity can be understood in a theoretically well controlled manner without needing to resolve the deep, unsolved issues of metallic criticality. We show that: 1) a BCS-Eliashberg treatment remains valid outside of a parametrically narrow interval about the NQCP; 2) the symmetry of the superconducting state (d-wave, s-wave, p-wave) is typically determined by the non-critical interactions, but Tc is enhanced by the nematic fluctuations in all channels; 3) in 2D, this enhancement grows upon approach to criticality up to the point at which the weak coupling approach breaks-down, but in 3D the enhancement is much weaker. Preliminary results of determinental quantum Monte-Carlo studies of the true critical regime will also be presented.
Faculty Host: Rafael Fernandes
Friday, April 10th 2015
Speaker: Laura Chomiuk, Michigan State
Subject: The Progenitors of Type Ia Supernovae: Clusters from Explosion Environments and Galactic Binaries
While astronomers generally agree that Type Ia supernovae mark the complete disruption of a white dwarf star, the mechanism for destabilizing the white dwarf and driving it to this suicidal end remains a mystery. I will describe the current state of efforts to determine the progenitor systems of Type Ia supernovae, and detail our team's efforts to narrow the possibilities with sensitive measurements of the environments of nearby supernovae. Finally, I will compare what we know about Type Ia supernovae with recent observations of Milky Way binary stars, testing whether the white dwarfs in these real-world binaries may one day meet the violent end of Type Ia supernovae.
Speaker: Mazviita Chirimuuta, Department of History and Philosophy of Science, University of Pittsburgh
Subject: Ontology of Colour, Naturalized
Refreshments served in Room 275 Nicholson Hall at 3:15 p.m.
Can there be a naturalized metaphysics of colour—a straightforward distillation of the ontological commitments of the sciences of colour? In this talk I first make some observations about the kinds of philosophical theses that bubble to the surface of perceptual science. Due to a lack of consensus, a colour ontology cannot simply be read off from scientists' definitions and theoretical statements.
I next consider three alternative routes towards a naturalized colour metaphysics.
1) Ontological pluralism—endorsing the spectrum of views associated with the different branches of colour science.
2) Looking for a deeper scientific consensus.
3) Applying ideas about emergent properties that have been useful elsewhere in biology.
Sponsored by the Minnesota Center for Philosophy of Science.
3:35 pm:
Speaker: Brita L. Nellermoe, University of St. Thomas
Subject: The gap: Where faculty perceptions of teaching and learning disconnect from practice.
Faculty perceptions of teaching and learning and the functionality of those perceptions in the classroom have been studied for over 20 years now. Understanding of these ideas has led to curriculum changes that better engage students and employ faculty understanding. These same studies have shown that there is a gap in implementation of these curriculum that can effect student outcomes. This talk will be an overview of past studies and discuss where this gap may lie. Next step research proposals will also be discussed.
Speaker: Jeremiah Mans, University of Minnesota
Subject: To be announced.
Monday, April 13th 2015
12:15 pm:
Speaker: Tanner Prestegard - University of Minnesota
Subject: Star formation at high redshift and the stochastic gravitational-wave background from black hole ringdown
Tuesday, April 14th 2015
Speaker: Terry Bretz-Sullivan, University of Minnesota
Subject: Collective Charge Transport in Ionic Liquid Strontium Titanate Nanowires
To be announced.
1:25 pm:
Space Physics Seminar in 210 Physics
Update: The space physics seminar is cancelled this week.
2:30 pm:
Biophysics Seminar in 110 PAN
There will be no seminar this week.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Chris Conklin
Subject: Hydrodynamics of Liquid Crystals
I will discuss the formulation of the hydrodynamic equations for liquid crystals, both in a traditional way [1,2] and using Onsager’s variational principle [3, 4]. I will then discuss a modification of these equations to account for ion impurities and describe the qualitative effect of these changes.
References:
[1] M. Kleman and O. D. Lavrentovich, Soft Matter Physics (Springer, New York, 2003).
[2] S. Groot and P. Mazur, Non-Equilibrium Thermodynamics (North-Holland, Amsterdam, 1963).
[3] M. Doi, J. Phys. Condens. Matter 23, 284118 (2011).
[4] F. M. Leslie, Contin. Mech. Thermodyn. 4, 167 (1992).
Wednesday, April 15th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker: Chen Guangyao, Iowa State University
Subject: BFLQ approach to lepton pair production in ultraperipheral heavy ion collisions
Basis Light Front Quantizition (BLFQ) is a nonperturbative treatment of quantum field theory, which adopts light-front quantization and the Hamiltonian formalism. BLFQ offers a first principles solution to many outstanding puzzles in nuclear and particle physics. BLFQ can also be used to study time-dependent scattering processes (tBLFQ). As its first realistic application, we apply principles of tBLFQ to lepton pair production in ultraperipheral heavy ion collisions. Due to the strong electromagnetic fields generated in heavy ion collision, perturbative approaches may lose its prediction power especially if two heavy ions collide with small impact parameter. As a non perturbative approach, tBLFQ takes into account the production and multiple-scattering of the leptons by the strong electromagnetic fields generated in the collisions inherently. Preliminary results with highly truncated basis will be presented.
3:35 pm:
Speaker: Reinhardt Schuhmann, Physical Review Letters
Subject: Physical Review Letters - managing a peer review journal
Refreshments served in Room 216 Physics after colloquium
Dr. Schuhmann is the Managing Editor of Physics Review Letters. Physical Review Letters receives ~11000 submissions per year, and publishes about 1/4 of them. Editors decide what to publish with extensive input from peer review, with roughly 70% of manuscripts reviewed. My talk will outline of how PRL manages peer review for such volume, with examples from correspondence, while it remains the premier physics journal. It is the most cited physics journal, with a Letter cited roughly every 90 seconds. PRL faces many challenges, however, as the publishing trends in some areas of physics shift, for example to smaller, less comprehensive, or more interdisciplinary venues. I will discuss some of these challenges, and what PRL is doing, and plans to do, to maintain a competitive journal that covers the full arc of physics. I would greatly appreciate your feedback and questions during and after the talk.
Thursday, April 16th 2015
Speaker: Tony Young
12:15 pm:
Speaker: Francis-Yan Cyr-Racine (Caltech/JPL)
Subject: A Particle Physicist's Nightmare: What If Dark Matter is Truly Dark?
Despite being ubiquitous throughout the Universe, the fundamental physics governing dark matter remains a mystery. Current dark matter searches implicitly assume that dark matter couples at some level to ordinary baryonic matter via Standard Model interactions. However, it remains possible that dark matter interacts so weakly with ordinary matter that it will escape detection with current and near-future technology. This particle physicist's nightmare forces us to consider other possible probes of dark matter physics. For instance, the evolution of cosmological density fluctuations on small causal length scales in the early epochs of the Universe is a very sensitive probe of the fundamental physics of dark matter. Studying the astrophysical structures that resulted from the gravitational collapse of fluctuations on these small scales can thus yield important clues about physical processes that took place in the dark sector in the early Universe. Today, most of these structures are locked-in deep inside the potential wells of massive galaxies, making the study of their properties difficult. Fortunately, due to fortuitous alignments between high-redshift bright sources and us, some of these galaxies act as spectacular strong gravitational lenses, allowing us to probe their inner structures. In this talk, we present a new statistical analysis formalism to extract information about mass substructures inside lens galaxies and discuss what this can tell us about dark matter physics.
1:15 pm:
Condensed Matter Seminar in 210 Physics
Speaker: David Hsieh, Institute for Quantum Information and Matter, CIT
Subject: Subtle structural distortions and a hidden magnetic phase in Sr2IrO4 revealed using nonlinear optical measurements
Please note: change of time for seminar, in effect for rest of semester.
Iridium oxides are predicted to host a variety of exotic electronic phases emerging from the interplay of strong electron correlations and spin-orbit coupling. There is particular interest in the perovskite iridate Sr2IrO4 owing to its striking structural and electronic similarities to the parent compound of high-Tc cuprates La2CuO4. However, despite theoretical predictions for unconventional superconductivity and recent observations of Fermi arcs with a pseudogap behavior in doped Sr2IrO4, no superconductivity has been observed in this compound so far. In this talk I will describe the nonlinear optical spectroscopy and wide field microscopy techniques that we have recently developed to resolve the symmetries of both lattice and electronic multipolar ordered phases on single domain length scales. I will show our results on the undoped Mott insulator Sr2IrO4 that reveal a subtle structural distortion and provide evidence for a hidden loop-current ordered magnetic phase that has previously eluded other experimental probes. The significance of these novel orders to magneto-elastic coupling and the pseudogap phase in Sr2IrO4 will be discussed.
Faculty Host: Natalia Perkins
Friday, April 17th 2015
There will be no colloquium this week.
Speaker: Francesca Bray, Social Anthropology, University of California Santa Barbara/University of Edinburgh
Subject: Happy Endings: Narratives of Reproduction in Late Imperial China
Refreshments served in Room 216 Physics at 3:15 p.m.
A rich resource for exploring the reproductive cultures of late imperial China ca. 1500 – 1800 is the abundant corpus of gynecology (fuke) treatises and case-histories. Demographic historians have recently used quantitative sources to argue that deliberate checks on fertility became common during this period, and that a rational, "modern" demographic mentality emerged which saw elite or better-off families matching numbers of children to resources and opportunities. In documenting specific attempts to intervene in natural processes, the fuke medical cases offer some very different perspectives on how childbirth and fertility were understood by Chinese families, what was considered a successful outcome, what a failure, and whose opinions counted. Here I focus on the temporal framing and narrative choices of selected fuke cases to ask what they can tell us about how practitioners and their clients attempted to control reproductive processes, and about the ideals, decisions and emotions associated with childbearing. The medical sources corroborate several elements of the demographers' model of reproductive agency and rationality, yet vividly portray the uncertainty, peril and intense emotions of reproductive life, and underline the heavy price the many women had to pay in order to produce a socially desirable family.
3:35 pm:
Speaker: Nathan Moore, Winona State University
Subject: Small Oscillations via Energy Conservation as a University Physics Lab
Speaker: Oriol T Valls
Subject: The competition between magnetism and superconductivity
Monday, April 20th 2015
12:15 pm:
Speaker: Liliya Williams, University of Minnesota
Subject: The behaviour of dark matter associated with central cluster galaxies
Tuesday, April 21st 2015
Speaker: Biqiong Yu, UMN
1:25 pm:
Space Physics Seminar in 210 Physics
To be announced.
2:30 pm:
Biophysics Seminar in 110 PAN
Speaker: Dr. Frank Vollmer,Max Planck Institute for the Science of Light, Erlangen, Germany
Subject: Advances in Biodetection with Optical and Mechanical Microresonators
Dr. Frank Vollmer will present his results on advancing chip-scale
biosensing capabilities with optical and mechanical microresonators.
In the optical domain, he has developed a microcavity biosensing
platform that is capable of monitoring single DNA molecules and
their interaction kinetics, hence achieving an unprecedented
sensitivity for label-free detection with light. In the mechanical
domain, he is developing a new force-based biosensing technique
based on the quartz crystal microbalance. By applying centrifugal
forces to a sample, it is possible to repeatedly and
non-destructively interrogate its mechanical properties in situ and
in real time.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Jiashen Cai
Subject: Superconductivity and spin density wave correlations in multiband metals
The coexistence of different ordered electronic states in metals has been discussed a lot. In iron pnictides, superconducting and magnetic spin density wave orders influence each other, e.g. they can support each other and lead to coexistence states [1]. This coexistence depends on the shape and area of the Fermi surface. In my presentation, I will briefly review the concepts of Fermi surface nesting and spin density waves. Then, a Ginzburg-Landau analysis in the vicinity of the crossing point of SC and SDW transitions and at T=0 will be discussed [2]. After that, I will present some numerical results and compare with the Ginzburg-Landau theory.
[1]Chubukov, Andrey V., D. V. Efremov, and Ilya Eremin. "Magnetism, superconductivity, and pairing symmetry in iron-based superconductors."Physical Review B 78.13 (2008): 134512.
[2] Vorontsov, A. B., M. G. Vavilov, and A. V. Chubukov, Physical Review B 81.17 (2010): 174538.
Wednesday, April 22nd 2015
10:30 am:
Thesis Defense in 110 PAN
Speaker: Xiangwei Tang, University of Minnesota
Subject: Observations of Plasma Waves at the Earth's Dayside Magnetopaus
This is the public portion of Ms. Tang's thesis defense.
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
3:35 pm:
Speaker: Margaret J. Geller, Harvard-Smithsonian Center for Astrophysics
Subject: The Ultimate Mass of Galaxy Clusters
Refreshments served in Tate Foyer after colloquium. This is the more technical portion of the Van Vleck Lecture series. This lecture is free and open to the public.
Clusters of galaxies are still forming at the current epoch. At the turnaround radius, the infall velocity induced by the mass concentration in the cluster just balances the Hubble flow. In the standard cosmology, galaxies within the turnaround radius will remain bound to the cluster and the mass within this radius is a good estimator of the ultimate cluster mass. Our redshift survey of nearly 100 massive clusters (HeCS: Hectospec Cluster Survey) in the redshift range 0.1 to 0.3 enables a number of important cosmological probes. These include a test of the cluster mass proxy derived from observations of the Sunyaev-Zeldovich effect. These data also enable measurement of mass profiles to large radius using the caustic technique. These profiles enable direct measurement of the accretion rate of galaxy clusters and of their ultimate mass. These measurements are new and direct tests of our understanding
of the growth of structure in the universe.
Thursday, April 23rd 2015
10:00 am:
Thesis Defense in PaN 110
Speaker: Addis Woldesenbet, University of Minnesota
Subject: Model-free analysis of quadruply imaged gravitationally lensed systems.
This is the public portion of Ms. Woldesenbet's thesis defense.
Speaker: Cody Carr and Kristy McQuinn
12:15 pm:
Speaker: Natsumi Nagata (Minnesota)
Subject: Direct search for electroweak-charged dark matter
We discuss a class of fermionic dark matter candidates which are charged under
the SU(2)_L gauge interactions, and evaluate their scattering cross section
with a nucleon, which is an important quantity for dark matter direct
detection experiments. Such a fermionic dark matter particle interacts with
quarks and gluons through one- and two-loop processes, respectively.
We will find that the resultant scattering cross sections lie around O(10^{-(46-48)}) cm^2, which exceed the neutrino background and thus can be reached in
future direct detection experiments.
1:15 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Alan Goldman, Iowa State University and Ames Laboratory
The Condensed Matter Seminar has been cancelled this week
7:00 pm:
Speaker: Margaret J. Geller, Harvard-Smithsonian Center for Astrophysics
Subject: Click: The 3D Universe
This is event is free and open to the public. It is scheduled to last an hour.
We live in the first time when it is possible to map the universe. We now know that galaxies like our own Milky Way trace the largest patterns in nature. These patterns, first uncovered by the CfA redshift survey in 1986-1989, extend for hundreds of millions of light years. Now with large telescopes, we can trace the evolution of these patterns and compare them with some of the worlds largest computer simulations. A new survey, HectoMAP shows us the patterns in the universe nearly 7 billion years ago. A HectoMAP movie takes us through the data. Comparison of HectoMAP observations with simulations provides new direct tests of our understanding of the evolution of structure in the universe.
Friday, April 24th 2015
Speaker: Chat Hull, Center for Astrophysics
Subject: From Filaments, to Core, to...Filaments?! The Role of Magnetic Fields in Multi-Scale, Filamentary Star Formation
In just the past few years, it has become clear that filamentary structure is present in the star-formation process across many orders of magnitude in spatial scale, from the galactic scales probed by Planck and Herschel all the way down to the AU-scale structures that ALMA has revealed within protoplanetary disks. A similar story can be told of magnetic fields, which play a role in star formation across the same vast range of size scales. Here I will first review my work on 1000 AU-scale dust polarization and magnetic fields in Class 0 protostellar envelopes, which were observed as part of the TADPOL survey using the 1.3 millimeter dual-polarization receiver system at CARMA. I will then highlight two 1000 AU-scale filamentary structures seen with CARMA before I reveal new, high resolution (150 AU!) ALMA 1.3 mm continuum observations of three protostars in Serpens. Even at such high resolution, these sources have a number of nearby, filamentary blobs/condensations/ companions, most of which coincide in a tantalizing way with the magnetic fields we mapped with CARMA. I will muse on what this all means, and on what questions may soon be answered by ALMA polarization observations of the same three sources.
Speaker: Leslie Tomory, History and Classical Studies, McGill University
Subject: London's Water Supply before 1800 and the Origins of Network Modernity
Refreshments served in Room 216 Physics at 3:15 p.m.
Since the middle of the nineteenth century, integrated technological networks have proliferated, especially in the Western world. This talk argues that one of the roots of this technologically networked society is London's water supply network. This infrastructure network was first founded in 1580, and by the 18th century, tens of thousands of houses were connected to it. The builders of this network solved a host of business, financial, legal and technological problems, and in doing so, created a model that was explicitly used by later network builders.
3:35 pm:
There will be no seminar this week.
Speaker: Cindy Cattell, University of Minnesota
Subject: To be announced.
Monday, April 27th 2015
12:15 pm:
Speaker: Mark Pepin - University of Minnesota
Subject: The CDMS Low Ionization Threshold Experiment
Speaker: Alexander Gorsky
Subject: Condensates and instanton-knot duality
Tuesday, April 28th 2015
Speaker: Joseph Sobek, UMN
Subject: Tunneling into the LAO/STO Interface
There will be no seminar this week.
1:25 pm:
Space Physics Seminar in 210 Physics
Speaker: Scott Thaller, University of Minnesota
Subject: Planetary Magnetospheres
2:30 pm:
Biophysics Seminar in 110 PAN
There will be no seminar this week.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Ruiqi Xing
Subject: Spin-Fermion Model for d-wave Superconductivity
The pairing mechanism in high temperature cuprate superconductors is an interesting problem. A low energy effective theory called spin-fermion model can be applied to study cuprates, and it's argued that pairing in cuprates is mediated by spin fluctuations. The model describes low-energy fermions interacting with their own collective spin fluctuations.
For phonon mediated superconductors, vertex corrections of phonon electron interactions and momentum dependence of fermionic self energy are small and neglected, due to the small ratio of sound velocity and Fermi velocity. This leads to the well known Eliashberg equations for superconducting state. For cuprates, Eliashberg-type theory is still valid, but for different reasons with phonon mediated superconductors, in spite of strong spin fermion interactions. Many 'fingerprints' of the spin fluctuation mediated pairing mechanism has been seen in the experiments.
This is the first talk of two consecutive Journal Club talks using spin-fermion model to study cuprates. I will focus on:
1.Introduction to spin-fermion model.
2.Summary of Eliashberg theory for electron-phonon pairing.
3.Perturbation theory and Eliashberg-type equations for spin fermion model.
4.Two of the fingerprints: Comparison with ARPES and neutron scattering experiments for superconducting state.
References:
1.Ar. Abanov , Andrey V. Chubukov & J. Schmalian, Quantum-critical theory of the spin-fermion model and its application to cuprates: Normal state analysis,
Advances in Physics,(2003) 52, 119-218
2.Andrey V. Chubukov, David Pines, Joerg Schmalian, Chapter 7 in 'The Physics of Conventional and Unconventional Superconductors' edited by K.H. Bennemann and J.B. Ketterson (Springer-Verlag) or arXiv:cond-mat/0201140
3.Ar. Abanov, A. Chubukov and J. Schmalian, Fingerprints of the spin-mediated pairing in the cuprates, J. Electron Spectroscopy, 117, 129 (2001).
Wednesday, April 29th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker: Dr. Rajan Gupta, Los Alamos National Laboratory
Subject: Probing TeV physics using neutron decays and nEDM
This talk will describe the calculations of iso-vector and iso-scalar nucleon charges g_A, g_S and g_T. These quantities are needed to probe new physics in precision experiments of neutron decay and electric dipole moment nEDM. Discussion of lattice QCD results will address systematic uncertainties associated with the lattice volume, lattice spacing, quark mass and renormalization of the novel CP violating operators. I will provide results for the quark electric dipole moment contribution to nEDM and the status of the calculations of the quark chromoelectric dipole moment being calculated by the LANL-RBC-UKQCD collaboration.
3:35 pm:
Speaker: Leslie Rosenberg, University of Washington
Subject: Searching for Dark-Matter Axions
Refreshments served in Room 216 Physics after colloquium
The axion is a hypothetical elementary particle whose existence would explain the baffling absence of CP violation in the strong interactions. Axions also happen to be a compelling dark-matter candidate. Even if dark-matter axions were to comprise the overwhelming majority of mass in the universe, they would be extraordinarily difficult to detect. However, several experiments, either under construction or taking data, would be sensitive to even the more pessimistically coupled axions. This talk describes the current state of these searches.
Thursday, April 30th 2015
Speaker: Vihang Mehta and Claudia Scarlata
12:15 pm:
Speaker: Erich Poppitz (Toronto)
Subject: Confining strings on R^3xS^1
I will begin with a brief and qualitative (but self-contained) overview of the semiclassically calculable small-S^1 confining dynamics in deformed Yang-Mills theory and QCD(adj) (including N=1 super Yang-Mills). I will then study confining strings in these theories, contrasting their properties with those of similar theories exhibiting abelian and nonabelian confining regimes, and will discuss unsolved problems for the future.
1:15 pm:
Condensed Matter Seminar in 210 Physics
Speaker: James Kakalios, UMN
Subject: Is the Conductivity in Amorphous Semiconductors Thermally Activated?
Please note: change of time for seminar, in effect for rest of semester.
Friday, May 1st 2015
09:00 am:
Symmetries and Interactions in Topological Matter Workshop in The Commons Hotel/Keller Hall 3-180
8:40 am
REGISTRATION
The Commons Hotel - Ballroom
2nd floor - to the right at the top of the escalators
8:55 am
Alex Kamenev
University of Minnesota
Welcome and opening comments
9:00 am
Charles Kane
University of Pennsylvania
Symmetry Protected Topological Semimetals
9:35 am
N.P. Ong
Princeton University
Evidence for the chiral anomaly in a Dirac semimetal
10:10 am
COFFEE BREAK
10:45 am
Alexander Altland
University of Cologne
Effective field theory of the disordered Weyl semimetal
11:20 am
M. Zahid Hasan
Princeton University
2D Topo.Superconductors, Weyl Semimetals and other exotic Cooper Pairing
11:55 am
Taylor Hughes
University of Illinois
at Urbana-Champaign
Interplay between Symmetry and Geometry in Topological Phases
12:30 pm
LUNCH BREAK
Lunch is on your own
LOCATION CHANGE - Keller Hall 3-180
2:00 pm
Michael Levin
University of Chicago
Braiding statistics and symmetry-protected topological phases
2:35 pm
Lesik Motrunich
California Institute of Technology
Fractionalization of Faraday lines in generalized compact quantum electrodynamics (CQED) and Symmetry Protected Topological phases and Symmetry Enriched Topological phases of CQED
3:10 pm
Xie Chen
California Institute of Technology
Time reversal invariant gapped boundaries of the double semion state
3:45 pm
COFFEE BREAK
4:15 pm
Leon Balents
University of California,
Santa Barbara
Metal-insulator transition and beyond in the pyrochlore iridates
4:50 pm
James Analytis
University of California, Berkeley
Novel transport and magnetic phenomena in strongly spin-orbit coupled materials
5:25 pm
Donna Sheng
California State University, Northridge
Topological Spin Liquid and Symmetry Characterization for Triangular Lattice Spin 1/2 J1-J2 model
Speaker: John Vaillancourt, SOFIA
Subject: The Polarized, Dusty Interstellar Medium
Polarized radiation at optical through millimeter wavelengths arises from thermally emitting dust grains whose axes exhibit a net alignment with the local magnetic field. As a result of this mechanism, polarization observations have successfully provided one of the few methods for measuring astrophysical magnetic field strengths and structure in a wide range of objects, from young protostars to external galaxies. The physical mechanisms proposed for aligning the grains have met some, but not every, observational test (i.e., correlations between polarization and reddening, spectral dependence, and grain composition). In the absence of a well-understood alignment model, the aforementioned magnetic field measurements would all be suspect.
Here I will introduce some key predictions from grain alignment models and discuss the observational successes and failures of each, leading to a preferred model in which interstellar radiation drives grain alignment. Additional tests of this radiative alignment torque model should be possible with new facilities such as ALMA, HAWC/SOFIA, and recently released Planck polarization data.
Speaker: Erik Angner, Department of Philosophy, George Mason University
Subject: There Is No Problem of Interpersonal Comparisons
Refreshments served in Room 275 Nicholson Hall at 3:15 p.m.
The proposition that interpersonal comparisons of utility are impossible has been part and parcel of mainstream economics for almost a century. These days, the proposition is invoked inter alia in arguments against happiness-based measures of well-being, which average happiness scores across populations in an effort to represent social welfare. In this talk, I will argue that interpersonal comparisons of utility are in fact implicit in virtually all traditional economic social welfare measures as well; if such comparisons are problematic, then, the problem is not unique to happiness-based measures. Fortunately, however, I will argue but that the proposition is a piece of zombie methodology: a methodological prescription that should have been dead and buried a long time ago. Social welfare measures have many problems, but interpersonal comparisons isn't one.
Sponsored by the Minnesota Center for Philosophy of Science.
3:35 pm:
To be announced.
Speaker: J. Woods Halley, University of Minnesota
Subject: Physics of the origin of life: the problem and paths to a solution.
Saturday, May 2nd 2015
08:30 am:
Soudan Laboratory Open House in Soudan Underground Laboratory
Last tour starts at 3:30 p.m.
The Soudan Underground Physics Lab is holding an open house on Saturday, May 2, starting at 8:30 a.m. and continuing throughout the day. Visitors can travel 1/2-mile underground and discover the data collected during the years that the MINOS detector has been operating. The Fermi National Accelerator Lab has been sending a beam of neutrinos to the Soudan Lab since the first one was detected on March 20, 2005.
9:00 am
Dmitry Bagrets
University of Cologne
Quantum criticality of 1D topological Anderson insulators
9:35 am
Dale Van Harlingen
University of Illinois at
Urbana-Champaign
Transport and Josephson phenomena in hybrid superconductor-topological insulator devices
10:10 am
COFFEE BREAK
10:45 am
Sergey Frolov
University of Pittsburgh
Search for additional signatures of Majorana fermions in semiconductor nanowires coupled to superconductors
11:20 am
Liang Fu
Massachusetts Institute of Technology
Majorana Takes Charge
11:55 am
Jesper Nygard
Neils Bohr Institute
Progress in the materials science of hybrid nanowires for topological devices|
12:30 pm
LUNCH BREAK
Lunch is on your own
2:00 pm
Leonid Glazman
Yale University
Topological Superconductivity with Magnetic Atoms
2:35 pm
California Institute of Technology
Majorana bound states in ferromagnetic atomic chains on a superconductor
3:10 pm
Rui-Rui Du
Rice University
Luttinger Behavior in the Ultralow Temperature Transport of InAs/GaSb Edge States
3:45 pm
COFFEE BREAK
4:15 pm
Frank Pollmann
Max Planck Dresden
Detecting topological orders in an infinite cylinder geometry
4:50 pm
Gil Refael
California Institute of Technology
Light-matters: from Floquet topological insulators to topolaritons
5:30 pm
POSTER SESSION
Sunday, May 3rd 2015
9:00 am
Katja Nowack
Cornell University
Imaging current in quantum spin Hall insulators
9:35 am
Ashvin Vishwanath
University of California at Berkeley
TBA
10:10 am
University of Minnesota
Supercurrent in the edge modes of InAs/GaSb
10:45 am
COFFEE BREAK
11:15 am
Jason Alicea
California Institute of Technology
Composite Dirac liquids: parent states for symmetric surface topological order
11:50 am
Lukasz Fidkowski
Stony Brook
3d symmetry protected phases and surface topological order
12:25 pm
Shinsei Ryu
University of Illinois at Urbana-Champaign
Symmetry-protected topological phases and cross-cap states
1:00 pm
Workshop Closing
Thank you for your participation
Monday, May 4th 2015
12:15 pm:
There will be no seminar this week. The Cosmology Lunchtime Seminar is finished for the semester.
Tuesday, May 5th 2015
12:20 pm:
Condensed Matter Sack Lunch in Tate Room 435
The sack lunch this week has been cancelled.
12:20 pm:
Space Physics Seminar in 210 Physics
Speaker: Paul Kellogg, University of Minnesota
Subject: Physics of Global Warming
There will be no seminar this week.
2:30 pm:
Biophysics Seminar in 110 PAN
There will be no seminar this week.
4:30 pm:
CM Journal Club in 236A Tate
Speaker: Xiaoyu Wang
Subject: Migdal's theorem and the spin-fermion model
Wednesday, May 6th 2015
1:25 pm:
Nuclear Physics Seminar in 435 Physics
There will be no seminar this week.
Speaker: Frank Pollmann, Max Planck Institute for the Physics of Complex Systems
Subject: Efficient numerical simulations of quantum many-body systems
Refreshments served in Room 216 Physics after colloquium. 3:35 pm Award Ceremony. 3:50 - 4:50 pm Colloquium
The simulation of quantum many-body systems on classical computers is notoriously difficult because of the exponential growth of the Hilbert space with the size of the system. This makes the study of some of the most fascinating problems in condensed matter physics extremely challenging. These include for example the understanding of high TC superconductors, as well as frustrated quantum magnets which might realize exotic phases of matter. In my talk, I will discuss how numerical approaches based on quantum information concepts allow for an efficient simulation of quantum many-body systems. In particular, I will introduce tensor-product state based methods that provide an optimized representation of the relevant corner of the Hilbert space. I will then demonstrate applications of matrix-product state based methods to obtain the ground state as well as the dynamics of strongly correlated quantum systems.
Faculty Host: Fiona Burnell
Thursday, May 7th 2015
Speaker: Brian O'Neill and Bob Gehrz
12:15 pm:
Speaker: Surjeet Rajendran (UC Berkeley)
Subject: Cosmological Relaxation of the Electroweak Vacuum
A new class of solutions to the electroweak hierarchy problem is presented that does not require either weak scale dynamics or anthropics. Dynamical evolution during the early universe drives the Higgs mass to a value much smaller than the cutoff. The simplest model has the particle content of the standard model plus a QCD axion and an inflation sector. The highest cutoff achieved in any technically natural model is 10^8 GeV
1:15 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Premala Chandra, Rutgers University
Subject: Frustration, Unexpected Order and Criticality in 2D Heisenberg Antiferromagnets
Please note: change of time for seminar, in effect for rest of semester.
Despite having finite spin correlation lengths at nonzero temperatures, frustrated two-dimensional Heisenberg magnets can develop long-range discrete order driven by short-range thermal spin fluctuations. Indeed this "order from disorder" phenomenon can lead to a finite-temperature Ising or Potts transition; it has recently been realized experimentally in the iron-based superconductors where it is responsible for the high-temperature nematic phase. We can also ask whether such a mechanism can lead to an emergent critical phase in an isotropic Heisenbergm magnet and we present a model where this is indeed the case. Our results are supported by both Wilson-Polyakov scaling and by Friedan's geometrical approach to nonlinear sigma models. We also discuss recent computational studies that support our results and discuss possible experimental realizations. We end with a more general discussion of the relation between Friedan scaling and 2D antiferromagnetism, and the possibility of using it to simulate generalized surgery-free Ricci flows of topological manifolds of broader mathematical interest.
Work done in collaboration with P. Orth, R. Fernandes, B. Jeevanesan, J. Schmalian, P. Coleman and A.I. Larkin.
Faculty Host: Rafael Fernandes
1:25 pm:
Speaker: Mitchell Wendt, University of Minnesota
Subject: The Detection of Bright but Rare Particles Carrying One or Two Distinct Fluorescent Colors: A Simulation Study
Friday, May 8th 2015
11:15 am:
Methods of Experimental Physics Poster Session in Physics and Nanotechnology Building Atrium
1:00 pm:
Speaker: Benjamin Ihde, University of Minnesota
Subject: Statistical Validation of Density-Specific-Volume Covariance Transport in a Two-Fluid System
Speaker: Josh Feinberg, U Minnesota, Earth Sciences
Subject: "Shining a Light Into the Dark: Using Cave Deposits to Illuminate Fine-Scale of the Geomagnetic Behavior
Cave deposits, such as stalagmites and stalactites, record the direction
and strength of the Earth's magnetic field as they grow. These geologic
materials offer a new source of information about the behavior of the
Earth's geodynamo. Speleothems record their magnetizations on seasonal
timescales, they are are not affected by the post-depositional processes
that effect marine and lake records, and can be dated with high precision using U-Th techniques. Recent improvements in the sensitivity of magnetic instrumentation and spatial resolution allow geophysicists to leverage speleothems as high-resolution paleomagnetic recorders. Modern studies enable us to resolve short-term geomagnetic variability, and characterize events such as geomagnetic reversals and excursions at an unprecedented scale.
Speaker: Michael Worboys, Life Sciences, University of Manchester
Subject: The Making of the Modern Dog: Breed, Blood and Britishness
Refreshments served in Room 216 Physics at 3:15 p.m.
In this talk I discuss the material and cultural manufacture of the modern dog. By 'modern dog', I mean an animal seen principally in terms of its 'breed'; that is, a specific physical conformation and related behavioural characteristics. Its inventors were British middle and upper class aficionados of dog shows, which were events of sporting competition, commercial speculation and sociality. They grew in popularity from the 1860s and by 1900 had spread, with their new types of canine, across the world. The ways in which dog shows were organised encouraged, and then required, dog breeders to reshape the existing variety of dog types into standardised forms called breeds, and to record the breed history of dogs in pedigree. The very first modern dog was a pointer named 'Major', so defined in 1865 by John Henry Walsh (aka 'Stonehenge'). He became the model for all subsequent members of the breed; however, in the spirit of the times, the 'improvement' was expected through breeding with and for good blood.
3:35 pm:
There will be no seminar this week.
There will be no seminar this week. The Intro to Research Seminar is finished for the semester.
Monday, May 11th 2015
1:25 pm:
Speaker: Exra Hart, University of Minnesota
Subject: Investigation of Missing Cell Events to Improve NOvA Far Detector Data
4:40 pm:
Speaker: Asad Kahn, University of Minnesota
Subject: Study of source of timing variations in ECAL using Z to ee events
Tuesday, May 12th 2015
4:30 pm:
CM Journal Club in 157 Tate
Speaker: Tobias Gulden
Subject: Bulk-edge correspondence in driven topological systems
In a static topological system the Chern number is equal to the number of chiral edge modes. However, in a periodically driven system there may be chiral edge modes present even in the case of trivial Chern number for all bands. In this talk I will use a toy model and Floquet theory to demonstrate this possibility, even if the Floquet operator is trivial i.e. the bulk ground state doesn't change under one period of evolution. Then I will show the derivation of a generalization to the Chern number that gives the number of edge states in a periodically driven topological system. In the end I will discuss the effects on a more realistic system with weak driving, as it may be realized in cold atom gases.
Reference:
Mark Rudner, Netanel Lindner, Erez Berg, and Michael Levin: PRX 3, 031005 (2013)
Thursday, May 14th 2015
1:15 pm:
Condensed Matter Seminar in 210 Physics
Speaker: Gia-Wei Chern, LANL
Subject: Stiffness from Disorder in Frustrated Quasi-2D Magnets
Please note: change of time for seminar, in effect for rest of semester.
Frustrated magnetism has become an extremely active field of research. The concept of geometrical frustration dates back to Wannier’s 1950 study of Ising antiferromagnet on the triangular lattice. This simple system illustrates many defining characteristics of a highly frustrated magnet, including a macroscopic ground-state degeneracy and the appearance of power-law correlations without criticality. In this talk I will discuss a simple generalization of the triangular Ising model, namely, a finite number of vertically stacked triangular layers. Our extensive numerical simulations reveal a low temperature reentrance of two Berezinskii-Kosterlitz-Thouless transitions. In particular, I will discuss how short-distance spin-spin correlations can be enhanced by thermal fluctuations, a phenomenon we termed stiffness from disorder. This is a generalization of the well-known order-by-disorder mechanism in frustrated systems. I will also present an effective field theory that quantitatively describes the low-temperature physics of the multilayer triangular Ising antiferromagnet.
Faculty Host: Natalia Perkins
Tuesday, May 19th 2015
4:30 pm:
CM Journal Club in 110 PAN
Speaker: Ioannis Rousochatzakis
Subject: Tower of States Spectroscopy
It is well known that spontaneous symmetry breaking can only take place in the thermodynamic limit. Yet, by general hydrodynamic and effective field theory arguments, fingerprints of this symmetry breaking are already encoded in finite volume system realizations. Here, I will discuss how to dig out these fingerprints in exact low-energy spectra of finite-size systems, a method which has been extremely successful over the last 20 years (starting e.g. with the first ‘numerical proof’ of long-range magnetic ordering in the 2D triangular antiferromagnet). The power of this method is not about system-size extrapolations (‘large enough’ system sizes are anyway quickly unreachable for many strongly correlated systems), but on the full exploitation of symmetry, which gives very stringent predictions for the structure and the exact content of the low-energy spectra. The underlying principles offer one of the most direct ways to understand the mechanism of spontaneous symmetry breaking, and as such it is a general and fundamental topic that goes beyond numerical simulations.
References:
[1] P. W. Anderson, PRB 86, 694 (1952)
[2] C. Lhuillier, cond-mat/0502464v1, chapter 2
[3] B. Bernu et al, PRL 69, 2590 (1992); PRB 50, 10048 (1994)
[4] P. Azaria et al, PRL 70, 2483 (1993)
[5] H. Neuberger and T. Ziman, PRB 39, 2608 (1989)
[6] P. Hasenfratz and F. Niedermayer, Z. Phys. B 92, 91-112 (1993)
Wednesday, May 20th 2015
1:00 pm:
Speaker: Alex Gude
Subject: Measurement of the phistar distribution of Z bosons decaying to electron pairs with the CMS experiment at a center-of-mass energy of 8 TeV
Measurements of the Z boson transverse momentum (QT) spectrum serves as
both a precision test of non-perturbative QCD and helps to reduce the
uncertainty in the measurement of the W boson mass. However, QT is
limited at its lowest values by detector resolution, and so a new variable,
Phi*, which performs better in the low QT region, is used instead.
This thesis presents the first measurement the normalized differential cross
section of Z bosons decaying to electron pairs in terms of Phi* at
sqrt(s) = 8 TeV. The data used in this measurement were collected by the CMS
detector at the LHC in 2012 and totaled 19.7/fb of integrated
luminosity. The results are compared to predictions from simulation, which are
found to provide a poor description of the data.
Friday, June 5th 2015
10:00 am:
Thesis Defense in 110 PAN
Speaker: Chaoyun Bao, University of Minnesota
Subject: Foreground Cleaning for Cosmic Microwave Background Polarimeters in the Presence of Instrumental Effects
Thursday, June 11th 2015
2:00 pm:
Thesis Defense in 110 PAN
Speaker: J J Nelson, University of Minnesota
Subject: Hopping Conduction and Metallic behavior in 2D Silicon Surface States induced by an Ionic Liquid
This is the public portion of Mr. Nelson's thesis defense.
Friday, June 12th 2015
08:00 am:
Saturday, June 13th 2015
11:00 am:
Memorial Service in First Unitarian Society, Minneapolis
There will be a memorial service for the late Professor Erwin Marquit at the First Unitarian Society in Minneapolis located at 900 Mount Curve Avenue.
Monday, June 15th 2015
08:00 am:
Thursday, June 18th 2015
3:00 pm:
Speaker: Ntiana Sachmpazidi, Central Michigan University
Subject: Internet Computer Coaches for Introductory Physics Problem Solving Implemented at CMU
A primary goal of introductory physics courses is to help students develop problem-solving and related critical thinking skills. A physics education research group at the University of Minnesota (UMN) has developed internet-based coaches to help students learn problem-solving, guiding students through a systematic framework for a number of individual physics problems. Initial tests with students from introductory physics courses at UMN indicate that users found the coaches helpful and that those students who actively used the coaches improved their performance on problem-solving components of course exams as compared to similar students who had not used the coaches. In this project, we investigate whether these positive results can be replicated at Central Michigan University. Students in an introductory physics course were given homework assignments that included the coach problems. Students could voluntarily use the coaches to help them complete their assignments. Keystroke data were recorded to monitor how/whether students used the coaches. Students also completed surveys containing questions regarding their opinions of the coaches. The data have been analyzed to address the following issues: the usage and usability of the coaches, their usefulness as perceived by students, and the characteristics of the students who do and don’t use the coaches. The ultimate goal of this research is to develop effective practices for teaching and learning problem-solving in introductory physics courses.
Wednesday, June 24th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.
Wednesday, July 1st 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.
Friday, July 3rd 2015
Tuesday, July 7th 2015
Speaker: Kyunghoon Lee, University of Michigan
Subject: Electron transport in two-dimensional materials: Graphene and beyond
Owing to their unique energy band structure and the ease of material synthesis, two dimensional nanomaterials, such as graphene, have become the ideal platform for observing novel electron transport phenomena. In particular, low energy quasiparticles in monolayer graphene behave like massless Dirac fermions, which have led to observations of many interesting phenomena, including Klein tunneling, anomalous Quantum Hall effect, etc. In contrast to the monolayer graphene, quasiparticles in bilayer graphene (BLG) are massive chiral fermions due to its parabolic band structure. Thus, BLG also gives a number of intriguing properties which are very different from those of monolayer graphene, including tunable band gap opening and anti-Klein tunneling, arising from chiral characteristics of charge carriers. However, unlike SLG, experimental works on chiral electron transport in BLG have received less attention.
In addition, other two-dimensional atomic layer crystals, such as atomically thin layered transition metal dichalcogenides (TMDCs), are also attractive material platform with unique electronic and optical properties, including indirect to direct band gap transition, and valley polarized carrier transport. However, study of the low temperature electron transport in atomic thin layered TMDCs is still in its infancy. One of the major hurdles for electron transport study lies in the large metal/semiconductor junction barrier for carrier injection, which leads to the contact resistance dominated charge transport in short channel nanoscale devices.
In this talk, I will show our first demonstrated successful synthesis of wafer scale BLG with high-homogeneity by low-pressure chemical vapor deposition (CVD). Next, I’ll discuss about the importance of chiral electron transport in BLG. I’ll present the signature of electronic cloaking effect with anti-Klein effect as a manifestation of chirality by probing phase coherent transport behavior in CVD bilayer graphene nanostructure. Finally, I’ll talk on the electron transport in two-dimensional TMDCs. I successfully fabricated monolayer MoS2 single electron transistors using low work function metal for the contact electrodes, and observed Coulomb blockade phenomena attributed to single electron charging on a fairly clean quantum dot.
Faculty Host: Vlad Pribiag
Wednesday, July 8th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.
Friday, July 10th 2015
Monday, July 13th 2015
08:00 am:
Tuesday, July 14th 2015
Speaker: Naslim Neelamkodan, Armagh Observatory
Subject: Physical conditions of molecular gas in photodissociation regions of the Large Magellanic Cloud
Wednesday, July 15th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.
Tuesday, July 21st 2015
1:25 pm:
Speaker: Kelly Stifter, University of Minnesota
Subject: The new Beam Halo Monitor system for the CMS experiment at the LHC
A new Beam Halo Monitor (BHM) detector system has been installed in the CMS cavern to measure the machine-induced background (MIB) from the LHC. This background originates from interactions of the LHC beam halo with the final set of collimators before the CMS experiment and from beam gas interactions. The BHM detector uses the directional nature of Cherenkov radiation and event timing to select particles coming from the direction of the beam and to suppress those originating from the interaction point. It consists of 40 quartz rods, placed on each side of the CMS detector, coupled to UV sensitive PMTs. For each bunch crossing, the PMT signal is digitized by a charge integrating ASIC and the arrival time of the signal is recorded. The data are processed in real time to yield a precise measurement of per-bunch-crossing background rate for each beam. This measurement is made available to CMS and the LHC, in order to provide real-time feedback on the beam quality and improve the efficiency of data taking. The BHM detector is now in the commissioning phase. An overview of the system and first results from Run II will be presented.
Wednesday, July 22nd 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.
Wednesday, July 29th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.
Monday, August 3rd 2015
11:00 am:
Thesis Defense in 110 PAN
Speaker: Abdul Malmi Kakkada, University of Minnesota
Subject: Role of Disorder in Quantum Crystals
This is the public portion of Mr. Kakkada's thesis defense
1:30 pm:
Thesis Defense in 110 PAN
Speaker: Bern Youngblood, University fo Minnesota
Subject: Noise and stochastic resonance in nanoscale magnetic particles
This is the public portion of Mr. Youngblood's thesis defense.
Wednesday, August 5th 2015
12:00 pm:
REU Weekly Seminar in 110 PAN
To be announced.
Friday, August 7th 2015
08:00 am:
Tuesday, August 11th 2015
10:00 am:
Thesis Defense in 110 PAN
Speaker: Susan Lein, University of Minnesota
Subject: Muon Neutrino Contained Disappearance in NOvA
This is the public portion of Ms. Lein's Thesis Defense.
The NOvA experiment studies neutrino oscillations in the NuMI neutrino beam from Fermilab. NOvA consists of two liquid scintillator tracking calorimeters placed
14 milliradians off-axis from the beam and 810 km apart. The NOvA experiment started taking data in 2014. This thesis establishes the neutrino energy estimation procedures used to determine the oscillation parameters sin^2 theta_23 and Delta m_{32}^2.
Wednesday, August 12th 2015
Speaker: REU Stduents, with Welcome by Alex Kamenev, University of Minnesota
Subject: See abstract for titles
8:55 a.m., Alex Kamenev, Welcome
9:00 a.m., Katelyn Koiner (Lucy Fortson) "Galaxy Zoo and UKIDSS: comparing bars in disc galaxies in optical and infrared wavelengths"
9:20 a.m., Austin Riedl (Michael Zudov) "Effect of low-temperature illumination and annealing on magnetotransport in very high Landau levels"
9:40 a.m., Aditya Dhumuntarao (Joe Kapusta) "AdS/CFT on Pure SU(3) Gauge Theory"
10:00 a.m., Shannon Dulz (Prisca Cushman) "Monte Carlo Simulations and Polymerization of Neutron Veto Plastics for the SuperCDMS Experiment"
10:20 a.m., Coffee Break
10:40 a.m., Matthew Libersky (Allen Goldman) "Ionic liquid gating of strontium iridate"
11:00 a.m., Bryan Linehan (Marvin Marshak) "Measuring the Sun and Moon Cosmic Ray Shadow on the NOvA Far Detector"
11:20 a.m., Sadie Tetrick (Cindy Cattell) "Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss: a further study"
11:40 a.m., Jon Huber (Woods Halley) "Magnetite Anodes used in the electrolysis of water"
12:00 p.m., Lunch
12:45 p.m., Wilson Lough (Vuk Mandic) "Signal Processing and Detection of the Gravitational Wave Background"
1:05 p.m., Miranda Thompson (Jim Kakalios) "Electronic Conductance in Silicon Nanocrystalline Films"
1:25 p.m., Joseph Mullin (Greg Pawloski) "Exploring Neutrino Oscillations at the Minos Near Detector"
1:45 p.m., Coffee break
2:00 p.m., Phillip Dang (Paul Crowell) "Magnetotransport Properties of Co2MnSi and Co2FeSi Heusler Alloy Thin Films"
2:20 p.m. Kylie Hess (Roger Rusack) "Fabrication of a Cosmic Ray Detector and Creation of Accompanying Data-Processing Code"
2:40 p.m., Timothy Schuler (John Broadhurst) "Auditory Discrimination in the Human Brain"
3:00 p.m., Program ends
3:00 pm:
Speaker: Jianming Bian and Greg Pawloski, University of Minnesota
Subject: First Results from the NOvA Experiment
Light refreshments will be served in the PAN lobby after the seminar
NOvA, the world’s leading long-baseline neutrino-oscillation experiment, uses a beam originating at the Fermi National Accelerator Laboratory near Chicago to measure electron-neutrino appearance and muon-neutrino disappearance with a 14,000-ton detector in northern Minnesota. Understanding neutrinos is one of the most important goals of elementary particle physics and could lead to deeper understanding of the origin and evolution of the universe. University of Minnesota faculty, staff and students have played leading roles in the design and construction of the NOvA laboratory and detector, as well as in the analysis of data collected during the first year and a half of operation. This special seminar will present first results from NOvA’s electron- and muon-neutrino measurements, along with an overall introduction to the NOvA project and a discussion of future running plans and ultimate scientific reach.
Friday, August 21st 2015
10:30 am:
Thesis Defense in 110 PAN
Speaker: Andrew Galkiewicz, University of Minnesota
Subject: Magnetic domain wall dynamics in patterned nanowires
2:00 pm:
Thesis Defense in 110 PAN
Speaker: Kanika Sachdev, University of Minnesota
Subject: Muon to Electron Neutrino Oscillation in NOvA
NOvA is a long-baseline neutrino oscillation experiment optimized for electron neutrino appearance in the NuMI beam, a muon neutrino source at Fermilab. It consists of two functionally identical, nearly fully-active liquid-scintillator tracking calorimeters. The near detector (ND) at Fermilab is used to study the neutrino beam spectrum and composition before oscillation, and measure background rate to the electron neutrino appearance search. The far detector, 810 km away in Northern Minnesota, observes the oscillated beam and is used to extract oscillation parameters from the data. NOvA's long baseline, combined with the ability of the NuMI beam to operate in the anti-neutrino mode, makes NOvA sensitive to the last unmeasured parameters in neutrino oscillations- mass hierarchy, CP violation and the octant of mixing angle theta23. This thesis presents the search for electron neutrino appearance in the first data collected by the NOvA detectors from February 2014 till May 2015. Studies of the NuMI neutrino data collected in the NOvA near detector and its effect on the oscillation measurement in the far detector are also presented.
Thursday, August 27th 2015
09:00 am:
Physics Force Public Show in Carousel Park, MN State Fair
12:00 pm:
Physics Force Public Show in Carousel Park, MN State Fair
2:00 pm:
Physics Force Public Show in Carousel Park, MN State Fair
Monday, August 31st 2015
10:00 am:
Physics Force Public Show in University of Minnesota Stage, MN State Fair
11:00 am:
Physics Force Public Show in University of Minnesota Stage, MN State Fair
Thursday, September 3rd 2015
2:00 pm:
Speaker: Daniel Stern, JPL
Subject: Surprising New Insights into Quasars from WISE and the Future of Wide-Field Infrared Surveys from Space
Friday, September 4th 2015
10:00 am:
Thesis Defense in 120 PAN
Speaker: Zhen Yuan, University of Minnesota
Subject: A Model for Gas Dynamics and Chemical Evolution of the Fornax Dwarf Spheroidal Galaxy
This is the public portion of Zhen Yuan's thesis defense.
We present an empirical model for the halo evolution, global gas dynamics and chemical evolution of Fornax, the brightest Milky Way (MW) dwarf spheroidal galaxy (dSph). Assuming a global star formation rate, we derive the evolution of the total mass and the rate of net gas flow for cold gas in a growing star-forming disk. We identify the onset of the transition from net inflow to a net outflow as the time at which the Fornax halo became an MW satellite and estimate the evolution of its total mass using the median halo growth history in the ΛCDM cosmology and its present mass within the half-light radius derived from observations. We find that the Fornax halo grew to M h (t_sat ) ≈ 1.8 × 10 9 M ⊙ at t sat ≈ 4.8 Gyr and that its subsequent global gas dynamics was dominated by ram-pressure stripping and tidal interaction with the MW. Then we build a chemical evolution model on a 2-D mass grid, using supernovae as the enrichment source of the gaseous system. We find that the key parameter of controlling the element abundances pattern is the supernovae mixing mass. It is set differently between two types of supernovae and between two phases, before and after t sat in our model. The choice is determined based on the supernovae remnant evolution as well as the global gas dynamics. We also find the metal loss in the outflow dominated phase is severe, which is empirically implemented in our model. The data generated from the standard case can explain the observational data very well, e.g., abundance ratio of α element to Fe as a function of metallicity [α/Fe] vs. [Fe/H], metallicity evolution as a function of time [E/H] vs. t and metallicity distribution function (MDF) for Mg, Ca and Fe.
Monday, September 7th 2015
Tuesday, September 8th 2015
12:20 pm:
Organizational Meeting
4:30 pm:
No Journal Club on Sep. 8th
Wednesday, September 9th 2015
10:10 am:
Biophysics Seminar in 110 PAN
There will be no seminar this week.
1:25 pm:
Speaker: Joseph Falson, MPI, Stuttgart
Subject: Electron correlation physics revealed in high mobility MgZnO/ZnO heterostructures
The two-dimensional electron system (2DES) hosted at the interface of MgZnO/ZnO now displays electron mobilities exceeding 1,000,000 cm2/Vs and electron scattering times comparable to the best AlGaAs/GaAs 2DES. In this talk I will discuss the growth technology used to create such high quality devices and introduce the physical phenomena they host at low temperatures. These themes include interaction-induced renormalization of the spin susceptibility of carriers and how it reveals the new facets of the fractional quantum Hall effect, along with non-equilibrium phenomena, such as microwave-induced resistance oscillations.
Faculty Host: Michael Zudov
Speaker: Masahiro Takimoto
Subject: Singlino Resonant Dark Matter
We consider a Dark Matter scenario in a singlet extension model of the Minimal Supersymmetric
Standard Model, which is known as nMSSM. We find that with high-scale supersymmetry breaking,
the singlino can obtain a sizable radiative correction to the mass. This opens a
Dark Matter scenario with resonant annihilation via the exchange of the Higgs boson.
We show that the current Dark Matter abundance and the Higgs boson mass can be
explained simultaneously. This scenario can be probed by XENON1T.
We also mention the possibility of Electroweak Baryogenesis at high temperature in this model.
If there exist vector like matters coupled to the singlet multiplet, the thermal effects deform
the Higgs potential at high temperature which derives a first order phase transition.
We show that a strong first order phase transition can occur when the temperature is around
the supersymmetry breaking scale, which can be TeV scale.
This talk is based on
K. Ishikawa, T. Kitahara and M. Takimoto,
Singlino Resonant Dark Matter and 125 GeV Higgs Boson in High-Scale Supersymmetry,''
Phys. Rev. Lett. 113, no. 13, 131801 (2014)
[arXiv:1405.7371 [hep-ph]].
and
K. Ishikawa, T. Kitahara and M. Takimoto,
Towards a Scale Free Electroweak Baryogenesis,''
Phys. Rev. D 91, no. 5, 055004 (2015)
[arXiv:1410.5432 [hep-ph]].
Speaker: Marvin Marshak, University of Minnesota
Subject: The Deep Underground Neutrino Experiment (DUNE)
Thursday, September 10th 2015
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
There will be no colloquium this week.
7:00 pm:
The 2015 Edythe and Irving Misel Family Lecture Series in McNamara Alumni Center, Memorial Hall
Speaker: Joseph Polchinski, The Kavli Institute for Theoretical Physics, University of California, Santa Barbara
Subject: Spacetime versus the Quantum
The lecture will be streamed live
I will talk about the search for a unified theory of the laws of physics including quantum mechanics, which governs the very small, and general relativity, which governs the very large. Stephen Hawking showed 40 years ago that these theories make conflicting predictions near black holes. This ignited a battle that continues to this day: either quantum mechanics must break down, or our understanding of spacetime must be wrong. The latest wrinkle is the `firewall’ paradox: if quantum mechanics is to be saved, then an astronaut falling into a black hole will have an experience very different from what Einstein’s theory predicts. This has led to many new ideas that may lead to the unification of these two great theories.
Faculty Host: Keith Olive
Friday, September 11th 2015
11:15 am:
Organizational Meeting
Speaker: Xiaowei Zhang, University of Minnesota
Subject: Giant Saturation Magnetization Material Fe16N2 and its Properties
There will be no seminar this week.
1:30 pm:
Thesis Defense in PAN 120
Speaker: Joe Kinney, University of Minnesota
Subject: Kinetic Inductance and Ionic Liquids, Tools for Understanding High-Tc Superconductors
This is the public portion of Mr. Kinney's thesis defense.
2:00 pm:
Speaker: Joseph Polchinski, The Kavli Institute for Theoretical Physics, University of California, Santa Barbara
Subject: Chaos in the Black Hole S-matrix
Statistical mechanics depends on chaos --- the sensitive dependence on initial conditions --- to produce ergodic mixing. It has been known for more than four decades that black holes satisfy thermodynamic laws, but the associated chaotic behavior has been discussed only recently. I review these developments, and extend them from eternal black holes to black holes that form and decay.
2:30 pm:
Speaker: No colloquium this week.
There will be no colloquium this week.
There will be no seminar this week.
Monday, September 14th 2015
12:45 pm:
Speaker: Introductory Organizational Meeting followed by Evan Skillman, University of Minnesota
Subject: Reionization and Dwarf Galaxies
The epoch of reionization has been predicted to leave an imprint on the star formation histories of dwarf galaxies. I will discuss the predicted effects and the observational tests.
Tuesday, September 15th 2015
12:00 pm:
Speaker: Dr. Mark Engebretson, Augsburg College
Subject: Two observational studies using Van Allen Probes data: A case study of an unusually strong, widespread EMIC wave event and its impact on the radiation belts, and a statistical study of low-harmonic m
4:30 pm:
CM Journal Club in 120 PAN
Speaker: Michael Schuett
Subject: Critical Phenomena in Hyperbolic Space
In the journal club we will discuss the behavior of a N-component φ4- -model in hyperbolic space based on Ref.1 I will motivate why such a study might be relevant for condensed matter physics and i will briefly sketch the derivation of the critical behavior of the model. I will follow the aforementioned reference and supplement the discussion for clarity.
1: Critical Phenomena in Hyperbolic Space, K. Mnasri, B. Jeevanesan and J. Schmalian ArXiv1507.02909
Wednesday, September 16th 2015
10:10 am:
Biophysics Seminar in 120 PAN
Speaker: Gant Luxton (Dept: Genetics, Cell Biology and Development, at UMN
Subject: Dystonia and Defective Nuclear-Cytoskeletal Coupling
The Luxton laboratory is focused on understanding the molecular mechanisms underlying the pathogenesis of dystonia. Dystonia is a neurological movement disorder characterized by repetitive muscle contractions that result in involuntary twisting of the extremities and abnormal posturing. People afflicted with dystonia can experience severe disruptions in their ability to perform routine tasks including walking and sitting. Dystonia is the third most common human movement disorder behind essential tremor and Parkinson’s disease. Despite its prevalence, we understand little about dystonia pathogenesis. The most common and severe form of inherited dystonia is early-onset or DYT1 dystonia. The symptoms of DYT1 dystonia first appear at a mean age of 12.5. DYT1 dystonia is caused by a mutation within the DYT1/Tor1a gene that encodes the evolutionarily conserved torsinA protein resulting in the deletion of a single glutamic acid residue (ΔE302/303, or ΔE). The mechanism through which the ΔE mutation causes DYT1 dystonia is unclear because the basic cellular function of torsinA is unknown. Our research has established torsinA as key regulator of nuclear-cytoskeletal coupling. We study the molecular mechanism of torsinA-dependent nuclear-cytoskeletal coupling using three powerful model systems: wounded fibroblast monolayers, the social amoeba Dictyostelium discoideum, and the Caenorhabditis elegans germline. Our research is holistic as we use biochemical, biophysical, cell biological, molecular genetic, and quantitative imaging approaches. Finally, we are actively screening for small molecules that modulate torsinA function in order to develop novel treatments for DYT1 dystonia.
1:25 pm:
Speaker: Jeremy Levy, University of Pittsburgh
Subject: Electron Pairing Without Superconductivity
Strontium titanate (SrTiO3) is the first and best known superconducting semiconductor. It exhibits an extremely low carrier density threshold for superconductivity, and possesses a phase diagram similar to that of high-temperature superconductors—two factors that suggest an unconventional pairing mechanism. Despite sustained interest for 50 years, direct experimental insight into the nature of electron pairing in SrTiO3 has remained elusive. Here we perform transport experiments with nanowire-based single-electron transistors at the interface between SrTiO3 and a thin layer of lanthanum aluminate, LaAlO3. Electrostatic gating reveals a series of two-electron conductance resonances—paired electron states—that bifurcate above a critical pairing field Bp of about 1–4 tesla, an order of magnitude larger than the superconducting critical magnetic field. For magnetic fields below Bp, these resonances are insensitive to the applied magnetic field; for fields in excess of Bp, the resonances exhibit a linear Zeeman-like energy splitting. Electron pairing is stable at temperatures as high as 900 millikelvin, well above the superconducting transition temperature (about 300 millikelvin). These experiments demonstrate the existence of a robust electronic phase in which electrons pair without forming a superconducting state. Key experimental signatures are captured by a model involving an attractive Hubbard interaction that describes real-space electron pairing as a precursor to superconductivity.
Faculty Host: Vlad Pribiag
There will be no seminar this week.
Speaker: Chandralekha Singh, University of Pittsburgh
Subject: Discussion: Facilitating thinking and learning in physics classroom
CANCELLED due to travel issues but a discussion is scheduled with Professor Singh from 5-6:00 in 230 Bruininks Hall for those who would like to pursue the topic less formally. Learning physics is challenging. There are only a few fundamental principles of physics that are condensed in compact mathematical forms. Learning physics requires unpacking these fundamental principles and understanding their applicability in a variety of contexts. In this talk, I will discuss our research that has implications for helping students learn to think like a physicist and improving their problem solving, reasoning and metacognitive skills.
Thursday, September 17th 2015
12:05 pm:
Speaker: Betsey Adams, Astronomy, NL
Subject: Probing the extreme edges of galaxy formation with ALFALFA
The ALFALFA HI survey has detected rare but extremely interesting HI sources that probe the extreme limits of systems that are able to form stars. These sources include the ultra-compact high velocity clouds (UCHVCs), some of which may represent gas-rich but (nearly) starless Local Group galaxies; the low-mass gas-rich SHIELD dwarf galaxies; and the "Almost-Dark" HI sources, which are clearly extragalactic HI detections that have no discernible optical counterpart in extant optical surveys. I will discuss these different source populations and how they are interconnected, highlighting one system, AGC 226067, that bridges the three categories. I will also focus in particular on the UCHVCs as candidate Local Group galaxies, highlighting one particular source, AGC 198606, for which HI observations with WSRT and deep WIYN/ODI optical imaging strongly support the hypothesis that it represents gas in a nearby dark matter halo.
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Chandralekha Singh, University of Pittsburgh
Subject: Improving student understanding of quantum mechanics
Refreshments to be served outside 230 SSTS after the colloquium.
Learning quantum mechanics can be challenging, in part due to the non-intuitive nature of the subject matter. I will describe investigations of the difficulties that students have in learning quantum mechanics. We find that the patterns of reasoning difficulties in learning quantum mechanics are often universal, similar to the universal nature of reasoning difficulties found in introductory physics. Moreover, students often fail to monitor their learning while learning quantum mechanics. To help improve student understanding of quantum concepts, we are developing quantum interactive learning tutorials (QuILTs) as well as tools for peer-instruction. The goal of QuILTs and peer-instruction tools is to actively engage students in the learning process and to help them build links between the formalism and the conceptual aspects of quantum physics without compromising the technical content.
Faculty Host: Kenneth Heller
7:00 pm:
The Third MIfA Public Lecture in Bell Museum Auditorium
Speaker: Chick Woodward, Minnesota Institute for Astrophysics
Subject: To the stars we will go — The worlds of exoplanets
Many movies over the last several decades have dramatized our fascination with alien life forms. But could aliens really exist? This lecture will highlight how astronomers detect and characterize planets outside our solar system that could harbor alien life. The recent revolution of exoplanet detections by the NASA Kepler mission and ground-based searches for exoplanets has given way to a new understanding of how common place other worlds are in the Galaxy. Our prospective of astrobiology as suddenly blossomed. Highlighted, as part of this presentation, will be a review of how astronomers detected and characterize these exo-planets, using techniques at the Large Binocular Telescope Observatory and elsewhere, a reflection on the potential requirements of the habitability zones in exo-planetary system, highlights from NASA missions designed to search for alien worlds, and the surprises within our own solar systems of bodies that may harbor life at present of may have supported life in the past. Indeed, we may be at the point where "E.T. will phone home."
Friday, September 18th 2015
11:15 am:
Speaker: Yong-Zhong Qian, University of Minnesota
Subject: Potential Signatures of High-Energy Neutrinos Produced by Relativistic Jets in Gamma-Ray Bursts and Core-Collapse Supernovae
We point out that high-energy neutrinos produced by relativistic jets can be annihilated with thermal neutrinos emitted by the associated accretion disks in gamma-ray bursts and core-collapse supernovae. For a broad range of conditions, the emerging all-flavor spectrum for neutrinos of E >∼ 0.1 PeV is modified by a factor E^(−n) with n ≈ 0.4–0.5. Flavor evolution of accretion-disk neutrinos does not affect this result but can change the emerging flavor composition of high-energy neutrinos. The above signatures provide potential tests of detailed models by IceCube.
Speaker: Han Fu, University of Minnesota
Subject: Collapse of electrons to a donor cluster in STO
Speaker: John Terning, U. California, Davis
Subject: Experimental Probes of Vacuum Energy
2:30 pm:
No colloquium on the 18th. See MIfA Journal Club listing for Thursday, September 17th.
Speaker: Mary Domski, University of New Mexico
Subject: Descartes and Newton on Deducing True Laws of Nature
Refreshments served at 3:15 p.m.
Descartes’ Principles of Philosophy (1644) and Newton’s Principia mathematica (1687) are two of the most important works of seventeenth century natural philosophy. Yet, when put side by side, it is far easier to identify differences between the texts than it is to pin-point similarities. Their laws of nature are a case in point. Descartes deduces his three laws from our knowledge of God and claims these laws are true insofar as they capture the world as God actually created it. Newton, in contrast, “deduces” his laws of motion “from the phenomena,” which suggests that these laws are true of the world as it is presented to our senses. In this paper, I first clarify the epistemic significance of Descartes’s and Newton’s competing “deductions” and competing notions of truth. Based on that treatment, I then highlight a significant and frequently overlooked point of agreement: Both Descartes and Newton adopt methods for establishing true laws of nature that allow us to know that bodies obey particular laws without a complete understanding of why they do, i.e., without requiring that we identify the natural processes and properties that explain the behaviors that the laws describe.
There will be no seminar this week.
Monday, September 21st 2015
12:45 pm:
Speaker: Caner Unal, University of Minnesota
Subject: Phenomenology for Non-Standard Axion Models
There is a strong experimental effort to discover the signal from primordial gravity waves. For the case that the inflation process happened in the simplest (standard) way, this signal reveals the energy scale of inflation, which is one of the most crucial questions about this era. However, there are other natural options that can be distinguished with distinct observational properties. This talk will concentrate on two models; each of them violates the standard case in a different way.
Tuesday, September 22nd 2015
12:00 pm:
Speaker: Prof. R. Linares, AeroMech, University of Minnesota
Subject: Uncertainty Quantification for Ionosphere-Thermosphere Density and Space Situational Awareness
4:30 pm:
CM Journal Club in PAN 120
Speaker: Marc Schulz
I will talk about a simple, paradigmatic example of how to understand exotic spin liquids (aka non-Abelian topological phases) in terms of more simpler ones as presented in Ref.[1]. The toric code model [2] will be used as a spin-1/2 lattice model giving rise to a (relatively) simple spin liquid. Using this as a starting point, a spin-1 model is constructed from the spin-1/2 model. Borrowing also explanations from Ref.[3], we shall see that the more complex spin liquid harbors topological excitations, which correspond to those of the (doubled) Ising theory.
[1] B. Paredes PRB 86, 155122 (2012)
[2] A. Y. Kitaev, Ann. Phys. 303, 2 (2003)
[3] B. Paredes, arXiv:1402.3567
Wednesday, September 23rd 2015
10:10 am:
Biophysics Seminar in 120 PAN
To be announced.
1:25 pm:
Speaker: Ivar Martin, Argonne
Subject: Mean field theory of (quasi)crystallization
Crystallization is one of the most familiar phase transitions; despite that, its theoretical understanding remains a major challenge. Why some crystal structures are more common than others? What selects between different close-packed orderings? Why do atoms sometimes prefer to arrange themselves quasi-periodically? While there is probably not a unique answer to these questions, in metallic alloys, I will argue that the driving physics may not be very different from that of various density (spin, charge, etc) instabilities within crystalline states.
Faculty Host: Rafael Fernandes
Speaker: Dan Ambrose, University of Minnesota
Subject: The µ2e Experiment
Thursday, September 24th 2015
12:05 pm:
Speaker: Terry Jones
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Mikhail Voloshin, University of Minnesota
Subject: Exotic Mesons and Baryons
Refreshments to be served outside 230 SSTS after the colloquium.
According to the original quark model template there are mesons consisting of a quark and an antiquark, and baryons made from three quarks. Strongly interacting particles that do not fit this template are called exotic. Experimental findings of recent years have uncovered existence of exotic mesons: tetraquarks, and baryons: pentaquarks, containing an additional heavy quark-antiquark pair. I discuss properties of such particles and the current theoretical approaches to understanding their internal dynamics.
Friday, September 25th 2015
11:15 am:
There will be no seminar this week.
Speaker: Yuting Wang, University of Minnesota
Subject: Entanglement entropy in Su-Schrieffer-Heeger model
Speaker: Richard Holman (CMU)
Subject: Open Effective Theories and Stochastic Inflation
What is the correct description of the effective theory for long wavelength modes in inflation? I'll argue that the standard EFT tools do not apply here and that a new description based on open effective theories is required. I'll discuss how this is related to the Stochastic Inflation program and how decoherence takes place in inflation.
2:30 pm:
Speaker: Laura Fissel, U Toronto
Subject: Mapping Magnetic Fields in Star Forming Regions with BLASTPol
A key outstanding question in our understanding of star formation is whether magnetic fields provide support against the gravitational collapse of their parent molecular clouds and cores. While direct measurements of magnetic field strength are challenging, observations of polarized thermal emission from dust grains aligned with respect to the local magnetic field can be used to map out the cloud magnetic field. In this talk I present early results from a BLASTPol, a sensitive balloon-borne polarimeter. BLASTPol observed the Vela C cloud during a 2012 Antarctic flight, yielding the most detailed submillimeter polarization map ever made of a molecular cloud forming high mass stars. Statistical comparisons between submillimeter polarization maps and 3-D numerical simulations of magnetized star-forming clouds are a promising method for constraining magnetic field strength, but uncertainty concerning how the dust polarizing efficiency varies as a function of density and other cloud parameters can make such comparisons difficult. Previous work suggests that this uncertainty can be reduced by studying the dependence of observed polarization fraction (p) on column density (N). In Vela C, I find that most of the structure in p can be modeled by a power-law dependence on two quantities: The first is N and the second is the local dispersion in polarization angle (S). This empirical model for p(N,S) provides new constraints for models of magnetized star-forming clouds and an important first step in the interpretation of the BLASTPol 2012 data set. Finally, I discuss a “next-generation” BLAST polarimeter, which is scheduled for a first Antarctic flight in late 2016. BLAST-TNG will have an order of magnitude increase in both spatial resolution and mapping speed and will map dozens of star-forming regions, placing important constraints on the role magnetic fields play in regulating star formation.
Speaker: Harold Cook, Brown University
Subject: A Different Descartes: The New Galen
Refreshments served at 3:15 p.m. A Charles E. Culpeper Lecture in the History of Medicine. Co-sponsored with the Center for Early Modern History.
Descartes is often said to be the French philosopher who gave us the mind-body problem. But he only began to write philosophy seriously in his 30s, living abroad. In his youth he apparently became we acquainted with libertine writers; when the assassination of the Queen Regent’s favorite, Concini, took place in 1617 he left to learn the art of war and became deeply immersed in French entanglements related to the Thirty Years War. After another short period in Paris his personal and political involvements seem to have caused him and his friends to feel threatened by the chief minister, Cardinal Richelieu. He spent the last twenty years of his life (1629-49) as an exile in The Netherlands, where he indeed had the leisure and ambition for writing about the nature of the world. Can we re-connect his mind and body?
Speaker: Rafael Fernandes, University of Minnesota
Subject: Theory of correlated materials: from high-temperature superconductors to quantum magnets
Sunday, September 27th 2015
12:00 pm:
School picnic in Boom Island Park
Please go here for map and RSVP information.
To help cover costs of this event, we are asking attendees to contribute 10forfaculty,and- 5 for postdocs, staff, and students (no charge for family members). If you would rather bring food, you may bring a side dish or dessert to share instead of paying. You can bring your payment to the picnic if you haven't already paid.
Monday, September 28th 2015
12:45 pm:
Speaker: Yong-Zhong Qian, University of Minnesota
Subject: Potential Signatures of High-Energy Neutrinos Produced by Relativistic Jets in Gamma-Ray Bursts and Core-Collapse Supernove
We point out that high-energy neutrinos produced by relativistic jets can be annihilated with thermal neutrinos emitted by the associated accretion disks in gamma-ray bursts and core-collapse supernovae. For a broad range of conditions, the emerging all-flavor spectrum for neutrinos of E >∼ 0.1 PeV is modified by a factor E^(−n) with n ≈ 0.4–0.5. Flavor evolution of accretion-disk neutrinos does not affect this result but can change the emerging flavor composition of high-energy neutrinos. The above signatures provide potential tests of detailed models by IceCube.
Tuesday, September 29th 2015
12:00 pm:
There will be no seminar this week.
4:30 pm:
CM Journal Club in PAN 210
Speaker: Tobias Gulden
Subject: Weyl semimetals and surface Fermi arcs: an introduction
Please Note: Meeting room will be changed to PAN 210 for the rest of the semester.
Recently the experimental discovery of surface Fermi arcs in TaAs were the first proof of existence of a Weyl semimetal [1]. The existence of these states in 3 spatial dimensions was theoretically proposed before, a short summary was published in a viewpoint [2]. The characteristic surface Fermi arcs appear as a projection of Weyl points in the bulk material. A Weyl point can only appear when either time reversal or spacial inversion symmetry are broken, and when there is an accidental degeneracy of two bands [3,4]. Following [4] I will show why this degeneracy is unlikely in 2 dimensions but rather generic in 3 dimensions, and how the projection of the Weyl points onto the surface yields a structure of surface Fermi arcs. However not every surface of a Weyl semimetal contains surface arcs, if two Weyl points of opposite chirality have the same projection the surface states cancel out. As example I will discuss the structure of the 24 Weyl points in the first experimentally known Weyl semimetal, TaAs.
[1] S.-Y. Xu et al, Science 349, 6248, pp.613-617 (2015)
[2] “Viewpoint: Weyl electrons kiss”, L. Balents, Physics 4, 36 (2011)
[3] H. Weng, C. Fang, Z. Fang, B.A. Bernevig and X. Dai, PRX 5, 011029 (2015)
[4] E. Witten, lectures at Princeton summer school 2015, online at https://www.youtube.com/channel/UCedUIgHkkHO-QKVhIqgkSfw
Wednesday, September 30th 2015
09:00 am:
Speaker: Juliette Alimena, Brown University
Subject: Search for Stopped Particles from Decays to Delayed Muons
Note the change from the usual time, this week only
Massive, long-lived particles do not exist in the SM, and so any sign of them would be an 3 indication of new physics. There are many BSM theories that predict long-lived particles, including split SUSY, hidden valley scenarios, GUT theories, and various SUSY models. Long-lived particles could be sufficiently massive that they would loose sufficient energy through ionization or hadronization, depending on the type of particle, that they would come to rest inside the detector material. A search for long-lived particles that stop in the CMS detector and decay to muons was performed. The decays of the stopped particles could be observed when there are no pp collisions in the detector, namely during gaps between bunch crossings. The analysis uses 19.7 1/fb of 8 TeV data collected by CMS in 2012, during a search interval of 293 hours of trigger livetime. We also set cross section limits for each mchamp mass as a function of lifetime, for lifetimes between 100 ns and 10 days. These are the first limits for stopped particles that decay to muons, and they are also the first limits for lepton-like multiply charged particles that stop in the detector.
1:25 pm:
Note change of day and time to Friday at 11:00 a.m., this week only.
Thursday, October 1st 2015
12:05 pm:
Speaker: Mellanie Galloway
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Lance Dixon, SLAC/Stanford
Subject: New Approaches to Quantum Scattering and the Payoff for the LHC
Refreshments to be served outside 230 SSTS after the colloquium.
The Large Hadron Collider is renewing its exploration of the energy frontier of particle physics, searching for new particles and interactions beyond the Higgs boson. For the LHC to uncover many types of new physics, the "old physics" produced by the Standard Model must be understood very well. For decades the central theoretical tool for this job was the Feynman diagram. However, Feynman diagrams are just too slow, even on fast computers, to allow adequate precision for complicated events with many jets of hadrons in the final state. Such events constitute formidable backgrounds at the LHC to many searches for new physics. Over the past few years, alternative methods to
Feynman diagrams have come to fruition. The new "on-shell" methods are based on the old principle of unitarity. They can be much more efficient because they exploit the underlying simplicity of scattering amplitudes, and recycle lower-loop information. Farther afield, the
new methods have led to intriguing new results in quantum gravity and in supersymmetric analogs of the Standard Model. I'll explain how and why these methods work, and present recent state-of-the-art results obtained with them.
Faculty Host: Tony Gherghetta
Friday, October 2nd 2015
11:00 am:
Speaker: D. Basov, UCSD
Subject: Interacting polaritons in van der Waals atomic layered materials
Please note change of day for the CM seminar, this week only.
Layered van der Waals (vdW) crystals consist of individual atomic planes weakly coupled by vdW interaction, similar to graphene monolayers in bulk graphite. These materials reveal diverse classes of light-matter modes (polaritons) including: surface plasmon polaritons in graphene, hyperbolic phonon polaritons in boron nitride, exciton polaritons in MoS2, cooper pair plasmon polaritons in high-Tc cuprates, topological plasmon polaritons and many others. I will overview recent nano-optical investigations conducted in our group aimed at probing interactions between different types of polaritons in artificial structures comprised of dissimilar vdW atomic layers.
References:
Fei et al. Nature 487, 82 (2012)
Dai et al. Science 343, 1125 (2014),
Basov et al. Reviews of Modern Physics 86, 959 (2014),
Post et al. PRL 115, 116804 (2015);
Dai et al. Nature Nanotechnology 10, 682 (2015),
Ni et al. Nature Materials October (2015).
Faculty Host: Andrey Chubukov
11:15 am:
There will be no seminar this week.
Speaker: Ziran Wang, University of Minnesota
Subject: Enhanced GMR by Wave Vector Filtering
Speaker: Lance Dixon, SLAC/Stanford
Subject: Bootstrapping Amplitudes and Wilson Loops in Planar N=4 Super-Yang-Mills Theory
2:30 pm:
Speaker: Oleg Gnedin, U Michigan
Subject: Towards Realistic Modeling of Galaxy Formation
Cosmological simulations of galaxy formation are rapidly advancing towards smaller scales. Current models can now resolve giant molecular clouds in galaxies and predict basic properties of star clusters forming within them. I will describe new theoretical simulations of the formation of the Milky Way throughout cosmic time. However, many challenges - physical and numerical - still remain. I will discuss how observations of massive star clusters and star forming regions can help us overcome some of them.
Speaker: Christopher Noble, Villanova University
Subject: Leibniz and Technology: What Automata, Mills, and Calculators Teach Us about Cognition
Refreshments served at 3:15 p.m.
Speaker: Andrey Chubukov, University of Minnesota
Subject: Superconductivity from repulsive interaction.
Monday, October 5th 2015
12:45 pm:
Speaker: Projjwal Banerjee, University of Minnesota
Subject: Stellar Origin of $^{10}$Be and a Low-Mass Supernova Trigger for the Formation of the Solar System
The abundances of short-lived radio-isotopes (SLR) in the early solar system (ESS) measured in meteorites provide crucial information about the events leading to the formation of the solar system. However, the origin of several of these SLR in the ESS is still uncertain. We show that one of the key SLR ^{10} Be can be made by neutrino-induced spallation during a core-collapse supernova (CCSN) in contrast to the current paradigm of ^{10} Be production exclusively by cosmic rays. In addition to ^{10} Be, we find that a recent low-mass CCSN, that occurred ~ 1 Myr before the Solar system formation, can self-consitently account for the ESS abundance of other SLRs such as ^{41} Ca, ^{107} Pd, ^{53} Mn, ^{60} Fe while also producing significant amounts of ^{26} Al, ^{36} Cl, ^{182} Hf, ^{135} Cs, and ^{205} Pb. This makes such a low-mass CCSN an attractive candidate for the event that triggered the formation of the solar system.
Tuesday, October 6th 2015
12:00 pm:
There will be no seminar this week.
4:30 pm:
CM Journal Club in PAN 210
No CMT Journal Club this week.
Wednesday, October 7th 2015
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
Speaker: Eugene Kolomeisky - University of Virginia
Subject: Optimal number of terms in QED series and its consequence in condensed matter implementations of QED
In 1952 Dyson put forward a simple and powerful argument indicating that the perturbative expansions of QED are asymptotic. His argument can be related to Chandrasekhar's limit on the mass of a star for stability against gravitational collapse. Combining these two arguments we estimate the optimal number of terms of the QED series to be . For condensed matter manifestations of QED in narrow band-gap semiconductors and Weyl semimetals the optimal number of terms is around 80 while in graphene the utility of the perturbation theory is severely limited.
Faculty Host: Boris Shklovskii
Speaker: Matt Strait, University of Chicago
Subject: Cosmogenic isotope production by muon capture in Double Chooz
Thursday, October 8th 2015
12:05 pm:
Speaker: Michael Gordon, Dinesh Shenoy, Roberta Humphreys
Speaker: Rouzbeh Allahverdi
Subject: Light/Multicomponent Dark Matter: A Simple Model and Detection Prospects
I present a simple extension of the Standard Model that gives rise to post-sphaleron baryogenesis by introducing colored scalar fields. The model can accommodate a fermionic dark matter (DM) candidate of O(GeV) mass whose stability is tied to proton stability. The supersymmetric extension of this model is straightforward and can realize a multicomponent DM scenario. I discuss prospects for direct and indirect detection of the DM candidate(s) and possible collider signals of the model.
3:15 pm:
School Photo in Steps of Civil Engineering Building
Refreshments will be served in the PAN lobby at 3:00 p.m.
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Giovanni Zocchi, UCLA
Subject: Nature’s molecular machines: a materials science approach
Refreshments to be served outside 230 SSTS after the colloquium.
Living matter, at the molecular scale, is different from usual matter. Biological molecules, specifically enzymes, deform without breaking, couple chemical reactions to molecular tasks. Nature’s molecular machines are not scaled down versions of macroscopic machines: molecular motors have nothing to do with Carnot cycles, and molecular pumps have nothing to do with hydrodynamics. So how do these molecules work. I will describe our advances in extracting universal mechanical properties of enzymes, and come to the surprising conclusion that the molecules of life are visco-elastic ! Enzymes “flow” from one solid – like conformation to another. As it turns out, the molecules we are made of behave dynamically like “silly putty”. Another universal conclusion is that any enzyme can be controlled mechanically, opening mechanical control for thousands of chemical reactions.
Faculty Host: Jochen Mueller
Friday, October 9th 2015
11:15 am:
There will be no seminar this week.
Speaker: Semere Tadesse, University of Minnesota
Subject: Surface acoustic wave induced optical transparency in photonic crystal cavity
Speaker: Matthew Walters (BU)
Subject: Black Hole Thermality from Conformal Field Theory
I will discuss recent work studying universal properties of gravity in anti-de Sitter (AdS) spacetime from the perspective of conformal field theory (CFT). Using the AdS/CFT correspondence, scattering with black holes can be rephrased in terms of correlation functions involving operators with large scaling dimension. I will present new methods for calculating these correlation functions in 2d CFTs which make the connection to black holes and gravity manifest. In particular, I will show that operators with large scaling dimension create a thermal background with the correct Hawking temperature, with interactions that can be described using new on-shell diagrams. I will then discuss the connection with eigenstate thermalization and the possibility of generalizing these results to theories in higher dimensions.
2:30 pm:
Speaker: Jim Truran, U Chicago
Subject: Synthesis of Silicon to Zinc Elements as a Function of Galactic Mass
Speaker: Richard Scheines, Carnegie Mellon University
Subject: The Revolution in Computational Causal Discovery
Refreshments served at 3:15 p.m.
Social scientists have been pursuing causal knowledge from observational studies for well over 100 years, with limited success. In the last 25 years, however, the computational and statistical methods available for causal modeling and discovery have exploded. I describe this revolution and illustrate it on some recent case studies in social and biomedical science. I also describe the challenges that still remain, including conceptual problems of defining variables and inferential problems arising from trying to measure them.
Speaker: Michael Zudov, University of Minnesota
Subject: To be announced.
Monday, October 12th 2015
12:45 pm:
Speaker: Ivana Orlitova & Anne Verhamme, Geneva Observatory, Switzerland
Subject: Using Lyman-alpha to detect galaxies that leak Lyman continuum
Determining the population of objects that reionized the Universe and maintained the subsequent thermal history of the intergalactic medium remains an urgent observational question. We use the Lyman-alpha line to identify the best candidates for Lyman continuum leakage. We will present Lya radiative transfer models, and their application to observational data.
Tuesday, October 13th 2015
12:00 pm:
Speaker: Aaron Breneman, University of Minnesota
Subject: Van Allen Probes Electric Fields and Waveforms (EFW) Survey of Chorus Waves with the Filterbank Instrument
4:30 pm:
CM Journal Club in PAN 210
Speaker: Samuel Ducatman
Wednesday, October 14th 2015
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
Speaker: Oleg Tchernyashov, Johns Hopkins
Subject: Anyons in solvable models of quantum magnets
Following Anderson's 1973 conjecture of a resonating valence-bond (RVB) state, theorists have been actively exploring quantum spin liquids – states of magnets without long-range order. In the last 15 years we have progressed from knowing what quantum spin liquids are not (states with local order) to understanding what they are. Several solvable models of spin liquids have been shown to be instances of lattice gauge theories (Kitaev). An alternative perspective is a picture of fluctuating closed strings (Wen). An open string contains two "fundamental" particles on its ends, which can be bosons, fermions, or anyons, depending on the model. Although these models, featuring multi-spin interactions, look contrived, more realistic models (e.g., Kitaev's honeycomb) share many of their exotic features. I will show how certain lattice defects of Kitaev's honeycomb model can bind Majorana zero modes.
Faculty Host: Natalia Perkins
Speaker: Jianming Bian, University of Minnesota
Subject: Exotic quark states at BESIII
In the quark model, hadrons are dominantly bound states of quark-antiquark pairs (mesons) or three quarks (baryons), but QCD also allows for hadronic states composed of more quarks bound together. Recently, BESIII, Belle and LHCb have confirmed the existence of four-quark and pentaquark candidates. These new states, along with experimentally observed resonances that do not fit well into the charmonium and bottomonium spectra, present challenges and opportunities for strong interaction theory. In this talk, I will review results on these exotic quark states that have been obtained by the BESIII experiment at the Beijing Electron Positron Collider II (BEPCII).
Thursday, October 15th 2015
12:05 pm:
Speaker: Karlen Shahinyan and Soroush Sotoudeh
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Oleg Tchernyshyov, Johns Hopkins University
Subject: Mechanics of magnetic solitons
Refreshments to be served outside 230 SSTS after the colloquium.
Magnets host a variety of solitons that are stable for topological reasons: domain walls, vortices, and skyrmions, to name a few. Because of their stability, topological solitons can potentially be used for storing and processing information. This motivates us to build economic, yet realistic models of soliton dynamics in magnets. E.g., a domain wall in a cylindrical ferromagnetic wire can be pictured as a bead on a string, which can move along the string and rotate about its axis. Its mechanics is counterintuitive: it rotates if pushed and moves if twisted. I will review basic models of ferro- and antiferromagnetic domain walls in one dimension and discuss examples from higher dimensions, e.g., vortices and skyrmions.
Faculty Host: Natalia Perkins
Friday, October 16th 2015
11:15 am:
There will be no seminar this week.
Speaker: Qianhui Shi, University of Minnesota
Subject: Quantum Hall stripes in tilted magnetic fields
Speaker: David Curtin (Maryland)
Subject: Towards a No-Lose Theorem for Naturalness
Theories of neutral naturalness can realize untuned solutions to the hierarchy problem while avoiding LHC current exclusion bounds on colored top partners. Their unusual signatures demonstrate the range of phenomena that can connected to stabilizing the electroweak scale, motivating searches for displaced vertices, exotic Higgs decays and emerging jets. I will give an overview of how to constrain these theories experimentally, and present recent work toward deriving a phenomenological model-independent 'no-lose theorem' for perturbative solutions to the hierarchy problem which rely on top partners, including neutral naturalness. This lends strong model-independent motivation to build both proposed future lepton and 100 TeV colliders, since both are needed as discovery machines of general naturalness.
2:30 pm:
Speaker: Randall McEntaffer, U Iowa
Subject: Nanofabrication for Astronomy: Small Features for Small Wavelengths
In the coming decades, the field of X-ray astronomy desires to accomplish several key science goals. Current X-ray observatories are incapable of addressing many of these including detailing the distribution of hot matter in the Universe. A large fraction of baryonic matter is theorized to exist in between galaxies. Detection of this matter and characterizing feedback mechanisms from galaxies are substantial advancements of our understanding that can be realized through soft X-ray spectroscopy. Future X-ray missions require diffraction gratings with high throughput and high spectral resolving power to achieve these goals. Recent advances in grating fabrication methods have enabled reflection gratings to obtain the necessary performance requirements. I will discuss these novel fabrication methods and detail our progress in fabricating custom grating groove profiles. These gratings have demonstrated very high X-ray diffraction efficiency and spectral resolving power during X-ray testing. I will detail these results and describe current and future space based applications of spectrometers based on such gratings.
Speaker: Ahmed Ragab, Harvard Divinity School
Subject: How to be a Patient: Patienthood and Medical Thinking in the Medieval Islamicate World
Refreshments served at 3:15 p.m. Co-sponsored with the Institute for Advanced Studies, the Center for Early Modern History, and the Consortium for the Study of the Premodern World
Speaker: Marvin Marshak, University of Minnesota
Subject: To be announced.
Sunday, October 18th 2015
10:10 am:
Biophysics Seminar in 120 PAN
Speaker: Paul Jardine, Dept. of Diagnostics and Biological Sciences, University of Minnesota
Subject: Role Reversal: Using Biology to Answer Questions in Physics
The broad field of molecular biology originated with the movement of physics into biological systems. With tremendous success, physicists were able to address fundamental questions in biological systems by applying physical methods of analysis. We are attempting to reverse these roles in that we are using a biological system to address complex questions in physics. We study the DNA packaging process in dsDNA viruses. During their assembly, these viruses compact DNA inside a protein shell, or capsid, to near crystalline density. Studying this system allows us to study phenomena not accessible to other experimental systems, including the confinement of charged polymers on the nanometer scale in real time. This work has revealed interesting principles of polymer dynamics, among them the forces that resist DNA confinement, the timescale of relaxation events, and the physical behaviour of molecules as they jam during translocation. I will present a brief overview of this work.
Monday, October 19th 2015
12:45 pm:
Speaker: Terry Jones (University of Minnesota)
Subject: Gravitational waves from binary supermassive black holes missing in pulsar observations
A quick review of the search for gravitational wave signatures in pulsar timing with the latest results from the Parkes Pulsar Timing Array.
12:45 pm:
Speaker: Terry Jay Jones, University of Minnesota
Tuesday, October 20th 2015
12:00 pm:
Speaker: Woods Halley, University of Minnesota
Subject: Life on Other Planets
4:30 pm:
CM Journal Club in PAN 210
Speaker: Yuriy Sizyuk
Wednesday, October 21st 2015
08:00 am:
Thesis Defense in 110 PAN
Speaker: Kwang Ho Hur, University of Minnesota
Subject: Advancing Fluorescence Fluctuation Microscopy in living cells: From non-stationary signals to tricolor FFS
This is the public portion of Mr. Hur's Thesis Defense.
Fluorescence fluctuation spectroscopy (FFS) is a powerful method for quantifying protein interactions. By exploiting the brightness of fluorescence intensity fluctuations we are able to measure the stoichiometry of protein complexes. FFS is particularly valuable because it allows real-time measurements within living cells, where protein complex formation plays a crucial role in the regulation of cellular processes. However, intensity fluctuations are frequently altered by the cell environment in subtle and unanticipated ways, which can lead to failure of the available FFS analysis methods. This thesis demonstrates that measuring in very small volumes, such as yeast and E. coli cells, can introduce a significant bias into the measured brightness as a result of cumulative sample loss, or photodepletion. This loss leads to a non-stationary signal, which is incompatible with the implicit assumption of a stationary process in conventional FFS theory. We addressed this issue by introducing a new analysis approach that serves as a foundation for extending FFS to non-stationary signals.
FFS measurements in cells are also currently limited to the study of binary interactions involving two different proteins. However, most cellular processes are mediated by protein complexes consisting of more than two different proteins. Observation of pairwise interactions is not sufficient to unequivocally determine the binding interactions involving three or more proteins. To address this issue, we extended FFS beyond binary interactions by developing tricolor heterospecies partition analysis to characterize ternary protein systems. The method is based on brightness analysis of fluorescence fluctuations from three fluorescent proteins that serve as protein labels. We verified tricolor heterospecies partition analysis by experiments on well-characterized protein systems and introduced a graphical representation to visualize interactions in ternary protein systems.
10:10 am:
Biophysics Seminar in 120 PAN
Speaker: Naomi Courtemanche, University of Minnesota, College of Biological Sciences
Subject: Mechanistic studies of formin-mediated actin assembly
Actin dynamics drive many cellular processes, including motility, cytokinesis and endocytosis. A host of actin-binding proteins controls actin filament nucleation, elongation, capping, branching and bundling. Members of the formin family of proteins nucleate new filaments and remain processively attached to actin filament barbed ends while promoting their elongation. Because we lack many of the details required to understand how formins function in cells, it is not known how they promote healthy cellular proliferation. I will present the results of three studies aimed at elucidating the mechanism of actin polymerization mediated by the S. cerevisiae formin Bni1p. First, I will describe experiments I performed using total internal reflection fluorescence microscopy to address the role of sequence organization in Formin Homology (FH) 1 domain-mediated transfer of profilin-actin to a formin-bound filament end. Second, I will describe a technique I developed called “actin curtains”, which I used to study the effect of linear force on formin-mediated polymerization. I will show that small linear forces dramatically slow formin-mediated polymerization in the absence of profilin, suggesting that force shifts the conformational equilibrium of the end of a formin-bound filament, but that profilin-actin associated with FH1 domains reverses this effect. Third, I will describe the effects of point-substitutions in the FH2 domain on the activity of Bni1p, which suggest that nucleation and elongation are separable functions of formins that involve different interactions with actin. These studies provide insight into the physical properties of formins, which will be useful in guiding future studies aimed at elucidating how sequence variations confer unique biological functions to formin isoforms expressed in the same cell.
1:25 pm:
Speaker: Jian Kang - University of Minnesota
Subject: Robustness of quantum critical pairing aginst disorder
Unconventional superconductivity is found in close proximity to a putative magnetic quantum critical point in several materials, such as heavy fermions, organics, cuprates, and iron pnictides. This led to the proposal that, in contrast to conventional electron-phonon superconductors, critical magnetic fluctuations promote the binding of the electrons in Cooper pairs. Experiments in many of these materials revealed that their superconducting transition temperature Tc is remarkably robust against disorder, particularly when compared to the predictions from the conventional Abrikosov-Gor'kov theory of dirty superconductors. In this talk, we investigate the impact of weak impurity scattering on the onset of the pairing state mediated by quantum critical magnetic fluctuations.We find that both the build-up of incoherent electronic spectral weight near the magnetic quantum phase transition, as well as the changes in the pairing interaction caused by disorder, lead to a significant reduction in the suppression rate of Tc with disorder, as compared to the Abrikosov-Gor'kov theory. Both effects are unique to the problem of electronically-mediated pairing, shedding new light on the understanding of unconventional superconductivity in correlated materials, where disorder is always present.
Faculty Host: Rafael Fernandes
There will be no seminar this week.
Thursday, October 22nd 2015
12:05 pm:
Speaker: Tony Young and Claudia Scarlata
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: James Bullock, University of California, Irvine
Subject: Dwarf Galaxies, the Local Group, and Cosmology
Refreshments to be served outside 230 SSTS after the colloquium.
The Local Group and the tiny galaxies that surround the Milky Way provide unique and detailed data sets for testing ideas in cosmology and galaxy formation. In this talk I will discuss how numerical simulations coupled with local "near-field" observations are informing our understanding of dark matter, the formation of the first galaxies, and the physical processes that act at the threshold of galaxy formation.
Faculty Host: Evan Skillman
Friday, October 23rd 2015
11:15 am:
Speaker: Joseph Kapusta (U. Minnesota)
Subject: Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions
Nuclei colliding at very high energy create a strong, quasi-classical gluon field during the initial phase of their interaction. We present an analytic calculation of the initial space-time evolution of this field in the limit of very high energies using a formal recursive solution of the Yang-Mills equations. We provide analytic expressions for the initial chromo-electric and chromo-magnetic fields and for their energy-momentum tensor. In particular, we discuss event-averaged results for energy density and energy flow as well as for longitudinal and transverse pressure of this system. Our results are generally applicable if the time is less than the inverse of the saturation scale Q_s. The transverse energy flow of the gluon field exhibits hydrodynamic-like contributions that follow transverse gradients of the energy density. In addition, a rapidity-odd energy flow also emerges from the non-abelian analog of Gauss' Law and generates non-vanishing angular momentum of the field. We will discuss the space-time picture that emerges from our analysis and its implications for observables in heavy ion collisions.
Speaker: Boyi Yang, University of Minnesota
Subject: Ionic liquid gating Sr2IrO4 single crystal
Speaker: Jessie Shelton, U. Illinois, Urbana-Champaign
Subject: Boosting Dark Matter Indirect Detection Signals with Black Holes
2:30 pm:
Speaker: Luke Roberts, Caltech
Subject: Nucleosynthesis and Neutrinos Near Newly Formed Compact Objects
The origin of the rapid neutron capture process (r-process) elements remains the biggest unsolved question in our understanding of the origin of the elements in the Milky Way. The r-process is responsible for producing around half of the elements heavier than iron, but the astrophysical site in which it occurs is still uncertain. The most likely sites for the formation of these nuclei involve dynamical events in the lives of neutron stars: the inner most regions of massive stars during core collapse supernovae and the merger of a neutron star and another compact object. In both of these environments, neutrinos, nuclear physics, and gravity play paramount roles in determining the evolution of the dense object itself and in determining what nuclei are synthesized in material that is ejected from the system. I will first discuss prospects for the r-process in the inner most regions core-collapse supernovae. This part of the talk will focus on my work studying neutrino emission during core-collapse supernovae, which has constrained the possible modes of nucleosynthesis in these events. Second, I will discuss nucleosynthesis in material ejected during binary neutron star mergers and my work predicting optical transients powered by the decay of ejected radioactive nuclei. I will highlight some of the uncertainties that exist in both of these scenarios, and how these uncertainties can be reduced with future theoretical and computational work with input from current and next generation observational and experimental facilities.
Speaker: Joseph Gabriel, University of Wisconsin-Madison
Subject: Origins of a Legitimation Crisis: Medical Science, Private Profit, and the Challenge of Big Pharma
Refreshments served at 3:15 p.m.
Richard Horton, editor-in-chief of The Lancet, has recently suggested that as much as half of all published medical literature may be false. Horton is not alone in making such a claim: over the past decade a growing number of influential critics from within the medical establishment have raised significant concerns about the evidentiary basis of contemporary medicine. Drawing from my recent work on intellectual property rights and the history of the pharmaceutical industry, in this talk I present some preliminary thoughts on the origins of what I see as a brewing legitimation crisis facing medical science. I suggest that one possible origin point for current concerns about the evidentiary basis of scientific medicine can be found during the late nineteenth century, when a series of therapeutic reformers re-conceptualized the relationship between medical science and monopoly rights in drug manufacturing. In doing so, these reformers sought to legitimize the role of private profit in the production of scientific knowledge; unintentionally, they also cast in doubt the very possibility of an objective science free from motivated self-interest. Since then, I suggest, the tension between private profit as both a productive force and a source of skepticism has been generalized to such an extent that the very possibility of actionable scientific knowledge in the medical domain now seems threatened.
Speaker: Lindsey Glaesener
Monday, October 26th 2015
12:45 pm:
Speaker: Marcos A. Garcia, University of Minnesota
Subject: No-scale inflation
Since the building-blocks of supersymmetric models include chiral superfields containing pairs of effective scalar fields, a multifield approach is particularly appropriate for models of inflation based on supergravity. We discuss two-field effects in no-scale supergravity models, showing that no-scale models naturally yield Planck-friendly results, in the form of an effective Starobinsky potential for the inflaton, or through a reduction of r to very small values, r<<0.1, due to an enhancement of the scalar power spectrum, in a model with a quadratic potential. We finally discuss inflaton decays and reheating bounds on inflation, including scenarios where the inflaton possesses direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions.
Tuesday, October 27th 2015
12:00 pm:
There will be no seminar this week.
4:30 pm:
CM Journal Club in PAN 210
Speaker: Han Fu
Subject: Luttinger Liquid
Abstract to be Announced
Wednesday, October 28th 2015
10:10 am:
Speaker: To be announced
Subject: Recent biophysical papers including technical developments, applications and quantitative biology
Biophysics Journal Club will meet whenever there is no biophysics seminar. The journal club is organized by Elias Puchner and Peter Martin.
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
Speaker: Xiang Cheng, University of Minnesota, Department of Chemical Engineering and Material Science
Subject: Impact response of granular materials: From the origin of the universe to catastrophic asteroid strikes
Granular materials are large conglomerations of discrete macroscopic particles. Examples include seeds, sand, coals, powder of pharmacy, etc. Though simple, they show unique properties different from other familiar forms of matter. The unusual behaviors of granular materials are clearly illustrated in various impact processes, where the impact-induced fast deformation of granular materials leads to emergent flow patterns revealing distinctive granular physics. Here, we explored the impact response of granular materials in two specific experiments:
First, we performed the granular analog to “water bell” experiments. When a wide jet of granular material impacts on a fixed cylindrical target, it deforms into a sharply-defined sheet or cone with a shape mimicking a liquid of zero surface tension. The jets' particulate nature appears when the number of particles in the beam cross-section is decreased: the emerging structures broaden, gradually disintegrating into diffuse sprays. The experiment reveals a universal fluid structure arising from the collision of discrete particles, which has a counterpart in the behavior of quark-gluon plasmas created by colliding heavy ions at the Relativistic Heavy Ion Colliders.
Second, we investigated impact cratering in granular media induced by the strike of liquid drops—a ubiquitous phenomenon relevant to many important environmental, agricultural and industrial processes. Surprisingly, we found that granular impact cratering by liquid drops follows the same energy scaling and reproduces the same crater morphology as that of asteroid impact craters. Inspired by this similarity, we develop a simple model that quantitatively describes various features of liquid-drop imprints in granular media. Our study sheds light on the mechanisms governing raindrop impacts on granular surfaces and reveals an interesting analogy between familiar phenomena of raining and catastrophic asteroid strikes.
Faculty Host: Vlad Pribiag
Speaker: Debarati Roy, Saha Institute of Nuclear Physics, Kolkata, India
Subject: Reconstructing Events with Jets at the LHC
Jets are very important tool in studying physics at a hadron collider like the LHC. They are the direct manifestations of quarks and gluons and they constitute the most essential tool to test QCD. In this seminar I will talk about the reconstruction of jets in the LHC. It involves combining the information from several detectors. It also includes the best possible calibration of the detector elements, jet energy correction from information of collision data as well as Monte Carlo, correcting from the effect of pile up events etc. Reconstructed jets are then utilized in computing several variables used in understanding perturbative as well as non-perturbative QCD effects, and also as efficient tools in search of new physics. Some of the tests of the Standard Model will be discussed.
Thursday, October 29th 2015
12:05 pm:
Speaker: Ryan Arneson and Michael Rutkowski
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Claudia Scarlata, University of Minnesota
Subject: Galaxy formation from a different perspective
Refreshments to be served outside 230 SSTS after the colloquium.
Our understanding of the formation and evolution of galaxies has been revolutionized in the past decade. Galaxies' growth is now thought to be regulated by the physics of baryons, through a self-regulating process wherein the star-formation rate, the gas accretion rate, and the gas outow rate all satisfy a slowly evolving equilibrium condition. However, there are still a number of problems/open questions with these baryon-dominated models, particularly when low-mass galaxies are looked at in detail. I will present recent results from the WFC3 Infrared Spectroscopic Parallel Survey (WISP) that we are conducting on the Hubble Space Telescope. This large program is identifying thousands of galaxies across a wide range of redshifts, spanning more that two thirds of the age of the universe. Our survey provides a selection function that is independent of galaxy stellar mass, and thus allows the study of those low mass objects that are mostly affected by energy feedback. These are the galaxies that provide the strongest constraints on galaxy formation models. I will also discuss our results in the context of future space based surveys such as Euclid and WFIRST-AFTA.
Friday, October 30th 2015
08:00 am:
Untitled in Physics
11:15 am:
There will be no seminar this week.
Speaker: Justin Watts, University of Minnesota
Subject: Room Temperature Kondo-Suppressed Spin Accumulation in Cu Non-Local Spin Valves
Speaker: Yonatan Kahn (Princeton)
Subject: The Goldstone and Goldstino of Supersymmetric Inflation
I construct an effective field theory (EFT) for the minimal degrees of freedom of supersymmetric inflation. These can be viewed as the goldstone of spontaneously broken time translations, and the goldstino of spontaneously broken SUSY, both of which are tied together in an interesting way through the structure of the SUSY algebra. I will outline some phenomenological consequences of the leading-order Lagrangian, including a modified goldstino/gravitino dispersion relation and a time-dependent gravitino mass phase. Finally, I will describe schematically the possible contributions of goldstino loops to inflationary correlators.
2:30 pm:
Speaker: Aleks Diamond-Stanic, U Wisconsin-Madison
Subject: Extreme Outflows and the Gas Around Galaxies
Our understanding of galaxy evolution centers around questions of how gas gets into galaxies, how it participates in star formation and black hole growth, and how it is returned to its galactic surroundings via feedback. On a global scale, measurements of the baryon density and the stellar mass function indicate that only 5% of baryons have formed stars by the present day, and this suggests that feedback from massive stars and supermassive black holes must prevent gas from forming stars in both low-mass and high-mass dark matter halos. I will present observational results on the geometry and kinematics of outflowing and inflowing gas around galaxies, including measurements of ejective feedback that is capable of quenching star formation by removing the cold gas supply. These results have broader implications for how gas is consumed and expelled at the centers of massive galaxies and for the limits of feedback from stellar radiation and supernovae. I will also discuss prospects for characterizing the physical properties of gas in and around galaxies using multi-wavelength spectroscopy with existing and future facilities.
Speaker: Margaret Morrison, University of Toronto
Subject: Fictional Models and Models as Fictions: Disentangling the Difference
EVENT CANCELLED!!!
Because models often represent the world in unrealistic ways an increasingly popular view in the philosophical literature classifies models as fictions, aligning the way they convey information with strategies used in various forms of fictional writing. While fictional models certainly play a role in science I want to resist the “models as fictions” view by arguing that it not only has the undesirable consequence of erasing an important distinction between different types of models and modelling practices, but it fails to enhance our understanding of the role that fictional models do play in the transmission of scientific knowledge.
Speaker: Vuk Mandic, University of Minnesota
Subject: Astrophysics and Cosmology with Gravitational Waves
Monday, November 2nd 2015
12:45 pm:
Speaker: Michael Boylan-Kolchin, University of Texas
Subject: High-redshift Science in the Milky Way
The Local Group affords us the opportunity to study the low-mass extremes of galaxy formation and cosmology. In this capacity, it presents some of the most enduring challenges to the very successful LCDM cosmology. I will discuss to what degree standard theoretical models of the local Universe match the growing volume and diversity of observations in the Local Group and beyond, with an emphasis on what these data may reveal about the nature of dark matter and the low-mass threshold of galaxy formation. These observations also have important implications for cosmic reionization, which is expected to play a central role in determining the abundance of low-mass galaxies around the Milky Way. I will argue that, even in the JWST era, the local Universe may be our best probe of low-mass galaxies at high redshift that are expected to be crucial for reionization.
Tuesday, November 3rd 2015
10:00 am:
Thesis Defense in PaN 120
Speaker: Tambe Ebai Norbert, University Of Minnesota
Subject: Search for massive long-lived neutral particles decaying to photons and large missing transverse energy using the Compact Muon Solenoid(CMS) particle detector.
This the public portion of Mr. Norbert's defense. His advisor is Yuichi Kubota.
The Standard Model (SM) despite its unmatched success in describing visible matter in the universe does not describe massive long-lived neutral particles. Therefore any sign of a massive long-lived neutral particle at the Large Hadron Collider(LHC) for example, would be an indication for new physics. Many models Beyond the SM like Gauge Mediated Supersymmetry Breaking Models(GMSB), Split SUSY models, Hidden Valley models and Large Extra Dimension models predict the existence of a massive long-lived neutral particle which decays into a photon and a gravitino.
Capitalizing on the excellent timing resolution of the Electromagnetic Calorimeter(ECAL) of the CMS detector, this thesis presents the search for events whose final state consist of at least one photon with late arrival time at ECAL compared to photons produced directly from proton-proton collisions at the LHC and large missing transverse energy in data recorded by the CMS detector from proton-proton collisions at 8 TeV center of mass energy in 2012. This data corresponds to 19.1/fb total integrated luminosity.
A photon from the decay of a massive long-lived neutral particle arrives late at ECAL due to the long lifetime of the massive long-lived neutral particle and is detectable using timing measurements of photons by ECAL. The large missing energy is used to infer the presence of an undetectable particle like the gravitino produced along with the photon from the decay of the massive long-lived neutral particle. The search covers particle lifetimes ranging from 3 to 40 nanoseconds(10^-9s).
12:00 pm:
Speaker: John Dombeck, University of Minnesota
Subject: Auroral Electron Precipitation Energy Flux Solar Illumination Effects and Transmissivity Characteristics
4:30 pm:
CM Journal Club in PAN 210
Speaker: Ruiqi Xing
Subject: Nambu-Goldstone Bosons(modes) and Adler's Principle
It is well known that spontaneous broken continuous symmetry leads to the existence of a massless bosonic excitation, which is called Nambu-Goldstone bosons(NGB). Examples of NGB are pions in high energy physics, phonons and magnons(spin wave) in condensed matter physics. NGB usually interact 'weakly' with other degrees of freedom, in the sense that only its gradient couples to other particles, and so they can survive. This is the so-called Adler's principle(or Adler zero). As first discovered by Adler, forward scattering amplitude of particles off a pion vanishes quadratically as the momentum of pions goes to zero. Similarly in condensed matter physics, phonons(or magnons) have vanishing coupling with electrons as the wavevector of phonons(or magnons) goes to zero. However, Adler's principle is not always true. There is a criterion [1], saying that if the broken symmetry generator doesn't commute with translations, the coupling is non-vanishing and sometimes it results in breakdown of Fermi liquid and overdamping of NGB. The case of non-vanishing coupling is relevant to nematic fermi fluid [2].
I will talk about:
(1)Introduction: Goldstone mode in phi-4 theory and why phonons and magnons are Goldstone modes. Goldstone theorem.
(2)Warm up: phonon-electron coupling.
(3)Major part: criterion of vanishing coupling (gradient coupling) between Goldstone bosons and electrons [1].
(4)More example: magnon-electron coupling in antiferromagnets [3][4].
(5)Comments: about long range interaction and Anderson-Higgs mechanism in superconductors.(if time permits)
[1] Haruki Watanabe and Ashvin Vishwanath, Proc. Natl. Acad. Sci. 111, 16314 (2014), http://arxiv.org/abs/1404.3728
[2] Vadim Oganesyan, Steven Kivelson, and Eduardo Fradkin, Phys. Rev. B 64, 195109 (2001)
[3] John R Schrieffer, Journal of Low Temperature Physics, 1995, 99(3-4): 397-402.
[4] Andrey V. Chubukov and Dirk K. Morr, Phys. Rep. 288, 355(1997)
Wednesday, November 4th 2015
10:10 am:
To be announced.
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
Speaker: Xiaoyu Wang, University of Minnesota
Subject: Crisscrossed stripe CDW in cuprate superconductors
The Sack Lunch and the CM Seminar will swap places, this week only.
There will be no seminar this week.
Speaker: Vlad Pribiag, University of Minnesota
Thursday, November 5th 2015
11:30 am:
Pizza lunch, lab tours, an overview of the School, and a chance to win a copy of the book The Physics of Superheroes.
12:05 pm:
Speaker: Amit Kashi and Stou Sandalski
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Uwe Kortshagen, University of Minnesota
Subject: Luminescence, Doping, and Transport Properties of Silicon Nanocrystals produced via Nonthermal Plasma Synthesis
Nonthermal plasma synthesis of nanocrystals is particularly suited for covalently bonded materials that require high temperatures to be produced with good crystallinity. Several years ago, we showed that plasma produced silicon nanocrystals are capable of high-efficiency photoluminescence, different from bulk silicon material. More recently, the capability of nonthermal plasmas to produce substitutionally doped nanocrystal materials has attracted attention, as substitutional doping had presented a significant challenge both for liquid and gas phase synthesis due to effects such as self-purification.
This presentation discusses the physics of plasma synthesis process. High photoluminescense quantum yields are achieved by careful surface functionalization through grafting alkene ligands to the nanocrystal surfaces. We also discuss the substitutional doping of silicon nanocrystals with boron and phosphorous using a nonthermal plasma technique. While the synthesis approach is identical in both cases, the activation behavior of these two dopants is found to be dramatically different. Finally, we present some experimental work on transport in films of highly phosphorous-doped nanocrystals, which indicates the approach to the metal-to-insulator transition.
This work was supported in part by the NSF Materials Research Science and Engineering Center under grant DMR-1420013, the DOE Energy Frontier Research Center for Advanced Solar Photophysics, and the Army Office of Research under MURI grant W911NF-12-1-0407.
Faculty Host: Boris Shklovskii
6:00 pm:
Subject: Overview of the school, lab tours, admissions information and a performance by the Physics Force.
Friday, November 6th 2015
11:15 am:
There will be no seminar this week.
12:20 pm:
Speaker: Adam Kaminski - Ames Laboratory
Subject: Interaction of electrons with collective excitations in conventional and unconventional superconductors
Please note the date and time change this week.
Interaction of electrons with collective modes plays a central role in theory of conventional superconductors and many models of unconventional superconductors. In cuprates for example, presence of such interaction was discovered almost two decades ago [1, 2], however there is no consensus as to its origin [2-5]. It is not even known whether it is responsible for driving the pairing or a mere spectator of the superconducting transition. One of the reasons for this situation is lack of momentum resolved data from classical superconductors that would serve as a baseline for identifying the physical nature of the coupling interaction and its role in the pairing mechanism. In this talk we will present such data from classical BCS superconductor MgB2 [6, 7] and review the old and new properties of the collective mode present in cuprates. In the classical superconductor, the coupling of the electrons to the phonon mode responsible for pairing remains almost unaffected across the critical temperature. This is unlike the situation in cuprates, where the signature of coupling to the collective mode vanishes above Tc. We also discovered new low energy spectral feature in MgB2 that is most likely a signature of coupling to the Leggett mode – a relative phase excitation of the two suprefluids present in this material.
[1] M. R. Norman et al., Phys. Rev. Lett. 79, 3506 (1997).
[2] M. R. Norman and H. Ding, Phys. Rev. B 57, 11089 (1998).
[3] A. Kaminski et al., Phys. Rev. Lett. 86, 1070 (2001).
[4] A. Lanzara et al., Nature 412, 510 (2001).
[5] G. H. Gweon, Nature 430, 187 (2004).
[6] D. Mou et al., Phys. Rev. B 91, 140502 (2015).
[7] D. Mou et al., Phys. Rev. B 91, 214519 (2015).
Faculty Host: Andrey Chubukov
Speaker: Joe Bramante (Notre Dame)
Subject: Dark Matter Ignition of Type Ia Supernovae
Recent studies of low-redshift type Ia supernovae indicate that half explode from sub-Chandrasekhar mass progenitor white dwarfs. This talk explains how PeV mass asymmetric dark matter would ignite sub-Chandrasekhar white dwarfs, and form star-destroying black holes in old galactic center pulsars.
2:30 pm:
Speaker: Charlotte Christensen, Grinnell University
Subject: Outflows and galactic recycling
The cycling of gas through galactic fountains links disks to halos. Here I use a suite of high-resolution simulations of galaxy formation to follow the outflow and re-accretion of gas. These simulations self-consistently generate outflows from the available supernova energy in a manner that successfully reproduces key galaxy observables including the stellar mass-halo mass, Tully-Fisher, and mass-metallicity relations. From them one can quantify the importance of ejective feedback, relative to the efficiency of gas accretion and star formation, to setting the stellar mass. I show that ejective feedback is increasingly important as galaxy mass decreases and that the effective mass loading factor is independent of redshift. By examining spatially-resolved gas loss and accretion, I show the extent to which outflows redistribute baryons through the disk and what fraction of outflowing material is later recycled.
3:30 pm:
Warren Lecture Series in Civil Engineering 210
Speaker: Victor Berdichevsky, Wayne State University, Detroit
Subject: Variational Principle for Probabilistic Measure in Theory of Materials with Random Microstructures and Beyond
Materials with random microstructures can be adequately described only in probabilistic terms. One of the problems that arise is: how to find probabilistic characteristics of local fields (stresses, currents, etc.), if probability distributions of material characteristics are known? This is one of the two topics of the talk. The second topic is closely related to the first one and concerned thermodynamics of microstructure evolution. It will be argued that classical thermodynamics is not sufficient for macroscopic description of solids, and there is one more law of thermodynamics which controls evolution of microstructures.
Speaker: Michael Reidy
Subject: How to Create a Physicist
Refreshments served at 3:15 p.m.
In 1850, John Tyndall was struggling to find his way: he was a thirty-year old graduate student in mathematics living in an attic in Marburg, completely unknown, utterly broke, and working himself to the brink of mental and physical exhaustion. Within three years, he held a distinguished professorship at the Royal Institution of Great Britain, working alongside the likes of Michael Faraday, and commanding sold-out crowds wherever he lectured. I will follow Tyndall for these three years as he rose from obscurity to stardom. The route he took will sound both surprising and familiar to modern ears. How he navigated his way through the social and scientific world of mid Victorian Britain can tell us much about how a physicist is created, both then and now.
Speaker: Roger Rusack, University of Minnesota
Subject: Research at the CERN Large Hadron Collider
Monday, November 9th 2015
12:45 pm:
There will be no seminar this week.
Tuesday, November 10th 2015
12:00 pm:
Speaker: John Wygant, University of Minnesota
Subject: Van Allen Probes observations of intense parallel Poynting flux associated with magnetic dipolarization, conjugate discrete auroral arcs, and energetic particle injection
4:30 pm:
CM Journal Club in PAN 210
Speaker: Mengxing Ye
Subject: Nambu-Goldstone bosons in non-reletivistic quantum systems
Wednesday, November 11th 2015
10:10 am:
Speaker: To be announced
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
No seminar this week.
There will be no seminar this week.
Thursday, November 12th 2015
12:05 pm:
Speaker: Karl Young and Liliya Williams
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: James Wells, University of Michigan
Subject: Higgs bosons and superconductors in the lab and throughout the universe
Refreshments to be served outside 230 SSTS after the colloquium.
I take an historical look at the developments of elementary
particle physics and condensed matter physics over the last century,
with focus on the interaction of these two grand areas of physics in
the context of spontaneous symmetry breaking. In particular, I compare
the discoveries of mutual interest in superconductivity and the
electroweak theory of particle physics and how the fields have
inspired each other. I describe how important the discovery of the
Higgs boson has been to particle physics and what it means for the
future. In the process I give an in-depth response to Anderson’s
recent statement in Nature: “Maybe the Higgs boson [of particle
physics] is fictitious!”
Faculty Host: Tony Gherghetta
Friday, November 13th 2015
11:15 am:
Speaker: Cheng-Hsien Li (U Minnesota)
Subject: Do Neutrino Wave Packets Overlap?
It is generally assumed that neutrino wave packets (WPs) do not overlap when they emerge from the source. We examine this assumption by modeling neutrinos as Gaussian WPs. A 3D solution with proper spherical shape has been derived to describe the propagation of a massless Gaussian WP. By using this 3D solution, we define the volume "occupied" by each WP to be the region in which the probability of finding the neutrino is 90%. A numerical factor is further defined as an indicator of the extent to which the WPs overlap in space. In particular, we consider the overlap among those neutrinos with mean energies differing by no more than the intrinsic energy uncertainty in a WP. The overlap factor depends on how sharp the transverse momentum distribution of the initial WP is and the differential production rate of the neutrino source. The estimate of the factor suggests that such WP overlap is significant for solar and supernova neutrinos and is potentially significant for neutrinos from radioactive sources and fission reactors. We raise the question of whether the ferminonic nature of neutrinos affect experimental observables if such overlap is significant.
Speaker: Brent Perreault, University of Minnesota
Subject: Semimetal Physics in Kitaev Spin Liquids
Semimetals and Spin Liquids are two sought-after states in modern condensed matter physics. In this talk I will discuss the Kitaev spin liquid and its excitations. I will then present Raman scattering as a probe for these exotic states in candidate spin-orbit coupled materials. It turns out that Raman scattering probes a fermionic quasiparticle in this system that realizes effective semimetal physics. Finally, I will speculate about Raman signatures of semimetal surface modes.
Speaker: James Wells, University of Michigan
Subject: Precision Analysis after the Higgs boson discovery
After the Higgs boson discovery we are able to refocus our efforts on precision analysis in search of new physics contributions now that the Standard Model and its parameters are known well. Some questions I will address concern self-consistent precision analysis frameworks, new physics expectations for deviations, and comparisons with experimental sensitivities for currently running and future facilities.
Speaker: Donna Bilak, Columbia University
Subject: Steganography and the Art of Secret Writing: New Perspectives on Michael Maier’s Alchemical Emblem Book, Atalanta fugiens (1618)
Refreshments served at 3:15 p.m.
In 1618, an alchemical savant named Michael Maier published an extraordinary alchemical emblem book, the Atalanta fugiens. Distinguished among the hermetic corpus for its fifty exquisite engravings of enigmatic alchemical images, which are set to music, Maier's Atalanta fugiens is an elegant audio-visual articulation of alchemical theory and practice for producing the philosophers’ stone, the panacea held to restore perfect health and longevity to humankind. The Atalanta fugiens is Maier's allegorical paean to wisdom achieved through the pursuit of true alchemy, and it is his evocation of a Golden Age published on the eve of the Thirty Years' War. However, this book contains a secret that has lain hidden for the past four hundred years, enciphered in its pages. This talk explores Maier's Atalanta fugiens as a virtuoso work of allegorical encryption that fuses poetry, iconography, music, mathematics, and Christian cabala to extol hermetic wisdom, while evoking alchemical technologies and laboratory processes - for Maier’s emblem book functions as a game or puzzle that the erudite reader must solve, decode, play.
Speaker: Elias Puchner, University of Minnesota
Subject: To be announced
Monday, November 16th 2015
12:45 pm:
Speaker: Julius Donnert, University of Minnesota
Subject: Magnetic Field Amplification in the Sausage Relic
Radio relics are believed to trace Mpc-scale shocks in the outskirts of massive galaxy clusters. They are likely sites of particle acceleration, where cosmic-ray electrons gain energy in the shock and become synchrotron bright in the magnetic field of the intra-cluster medium. Many models for radio relics require substantially larger magnetic fields than motivated from our general understanding of fields and their amplification in the outskirts of cluster. We present a new detailed model of the prototype of radio relics, the Sausage relic in CIZA J2242.8+5301, aimed to reproduce the recently observed spectral steepening in the relic. We also provide limits on the acceleration efficiency
required to model the relic, which puts tension on direct shock acceleration from the thermal pool.
Tuesday, November 17th 2015
12:00 pm:
Speaker: Sheng Tian, University of Minnesota
Subject: The Earth's magnetospheric cusp: a survey of conjunction events between the Polar and FAST spacecraft
4:30 pm:
CM Journal Club in PAN 210
Speaker: Jiashen Cai
Subject: Chiral superconductivity from repulsive interactions in doped graphene
Wednesday, November 18th 2015
10:10 am:
Biophysics Seminar in 120 PAN
Speaker: Paul Jardine, Dept. of Diagnostics and Biological Sciences, University of Minnesota
To be announced.
1:25 pm:
Speaker: Norman O. Birge, Michigan State University
Subject: Spin-triplet supercurrents in ferromagnetic Josephson junctions
When a superconductor (S) and a ferromagnet (F) are put into contact with each other, the combined S/F hybrid system exhibits altogether new properties. There is a proximity effect where electron pair correlations from S penetrate into F, but the pair correlations oscillate rapidly and decay over a very short distance due to the large exchange splitting between the spin-up and spin-down electron bands in F. In the presence of non-collinear magnetization, Bergeret et al. predicted that spin-triplet pair correlations are generated, which are immune to the exchange field and hence persist over much longer distances in F [1]. Furthermore, these triplet pair correlations satisfy the Pauli Exclusion Principle in a new and strange way: they are odd in frequency or time. Several groups have now observed convincing evidence for such spin-triplet correlations in a variety of S/F and S/F/S systems. Our approach is based on measuring the supercurrent in Josephson junctions of the form S/F’/F/F’’/S, with non-collinear magnetizations in adjacent ferromagnetic layers [2]. I will discuss our latest results toward controlling the supercurrent in these junctions [3], as well as how various types of ferromagnetic junctions could be used as memory elements in a fully superconducting random-access memory [4].
Work supported by the US DOE under grant DE-FG02-06ER46341, by Northrop Grumman Corporation, and by IARPA via U.S. Army Research Office contract W911NF-14-C-0115.
[1] F.S. Bergeret, A.F. Volkov, and K.B. Efetov, Phys. Rev. Lett., 86, 4096 (2001).
[2] T.S. Khaire, M.A. Khasawneh, W.P. Pratt, Jr., and N.O. Birge, Phys. Rev. Lett. 104, 137002 (2010); C. Klose et al, Phys. Rev. Lett. 108, 127002 (2012).
[3] W. Martinez, W.P. Pratt, Jr., and N.O. Birge, arXiv:1510.02144.
[4] E.C. Gingrich et al., arXiv:1509.05368.
Faculty Host: Vlad Pribiag
Speaker: Marianna Gabrielyan, University of Minnesota
Subject: Search for exotic contributions to $\nu_\mu \to \nu_e$ transitions with MINOS and MINOS+
The observed neutrino flavor transitions are currently explained by the three flavor neutrino oscillation phenomenon, considered to be the leading order mechanism behind the flavor transitions. Currently existing data from LSND, miniBooNE and reactor experiments demonstrate anomalies that could potentially be indications of non-standard neutrino phenomena. MINOS can probe transitions from muon neutrinos to electron neutrinos and search for anomalous behavior that cannot be explained by standard model neutrino oscillations. I will present the search for second order effects in the flavor transitions by analyzing the MINOS
νμ→νe- channel.
Thursday, November 19th 2015
12:05 pm:
Speaker: Marc Kuchner, NASA Goddard
Subject: Disk Detective: Crowdsourced Discovery of Planetary Systems
Have you discovered a planetary system today? If not, don't worry. At DiskDetective.org, you can help scour the WISE data archive to find new planetary systems and candidate advanced extraterrestrial civilizations. Volunteers at this new citizen science website have already performed almost 1.5 million classifications of WISE sources, searching a catalog 8x the size of any previously published survey. Through a follow-up spectroscopic and imaging campaign in both hemispheres we are re-observing many user-classified Objects of Interest to further vet them for background contaminants and derive better spectral types. Come by to hear about our growing catalog of candidate debris disks, protoplanetary disks, and other interesting objects with 22 micron excess all around the sky--and some strange stories about doing science with 28,000 helpers.
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Joe Lykken, Fermilab
Subject: Neutrinos are Everywhere
Refreshments to be served outside 230 SSTS after the colloquium.
The story of Fermi's "little neutral ones" has already many surprises and inspiring examples of daring experimental initiative. Today a host of new experiments are trying to unlock the secrets of these elusive particles.
Faculty Host: Tony Gherghetta
Friday, November 20th 2015
11:15 am:
Speaker: Yanyan Bu, Ben-Gurion University of the Negev, Israel
Subject: Linearly resummed hydrodynamics from gravity
Using fluid/gravity correspondence, we study all-order resummed hydrodynamics in a weakly curved spacetime. The underlying microscopic theory is a finite temperature \mathcal{N}=4 super-Yang-Mills theory at strong coupling. To linear order in the amplitude of hydrodynamic variables and metric perturbations, the fluid's stress-energy tensor is computed with derivatives of both the fluid velocity and background metric resummed to all orders. In addition to two viscosity functions, we find four curvature induced structures coupled to the fluid via new transport coefficient functions, which were referred to as gravitational susceptibilities of the fluid (GSF). We analytically compute these coefficients in the hydrodynamic limit, and then numerically up to large values of momenta. We extensively discuss the meaning of all order hydrodynamics by expressing it in terms of the memory function formalism, which is also suitable for practical simulations. We also consider Gauss-Bonnet correction in the dual gravity, which is equivalent to some 1/N corrections in the dual CFT. To leading order in the Gauss-Bonnet coupling, we find that the memory function is still vanishing.
Speaker: Yangmu Li, University of Minnesota
Subject: Charge transport of cuprate superconductors: electron- vs. hole-doped
Speaker: Seyda Ipek, Fermilab
Subject: Baryogenesis via pseudo-Dirac Fermion Oscillations
In order to explain the baryon asymmetry of the Universe, we need extra CP violation, and an out-of-equilibrium process. Supersymmetric theories with a global U(1) symmetry solve the SUSY flavor and CP problems. They also have pseudo-Dirac gauginos with particle--antiparticle oscillations. If the gauginos decay out-of-equilibrium, and if there is CP violation in the oscillations, can they produce the baryon asymmetry? You should come and learn!
2:30 pm:
Speaker: Katsumi Matsumoto, Geology, U of Minnesota
Subject: Global Carbon Cycle and Climate Change
Global climate is undergoing change now. In the geologically recent past, global climate has experienced large swings as ice sheets waxed and waned, causing global sea level to fluctuate by ~120 m. These changes are accompanied by significant changes in the CO2 content of the atmosphere, indicating a close but incompletely understood link between CO2 and global climate. It is also unclear why and how atmospheric CO2 can vary naturally by as much as it did in the recent past. This presentation will explore these issues and attempt to put the ongoing climate change in perspective.
Speaker: James Justus, Florida State University
Subject: Ecological Theory and the Niche
Refreshments served at 3:15 p.m.
At least until Hubbell’s neutral theory emerged, no concept was thought more important to theorizing in ecology than the niche. Without it––and its highly abstract definition by Hutchinson in particular––technically sophisticated and well-regarded theories of character displacement, limiting similarity, and many others would seemingly never have been developed. The niche concept is also the centerpiece of perhaps the best candidate for a distinctively ecological law, the competitive exclusion principle. But the incongruous array of proposed definitions of the concept squares poorly with its apparent centrality. I argue this definitional diversity reflects a problematic conceptual imprecision that challenges its putative indispensability in ecological theory. Recent attempts to integrate these disparate definitions into a unified characterization fail to resolve the imprecision.
Speaker: Cindy Cattell, University of Minnesota
Subject: Particle acceleration in space plasmas: 'Living with a Star'
Monday, November 23rd 2015
12:45 pm:
Speaker: Alexander van Engelen, CITA, University of Toronto
Subject: Lensing and Other Results from ACTPol
Surveys of the CMB from ground-based observatories have revealed much about cosmology, in particular by measuring effects on CMB photons since recombination. In this talk, I will summarize results from the ongoing ACTPol survey, highlighting in particular the measurement of gravitational lensing by matter between us and the CMB recombination surface. I will discuss challenges with these measurements and also look forward to what will be possible with upcoming surveys such as SPT-3G, AdvACT, and CMB-S4.
Faculty Host: Shaul Hanany
4:00 pm:
Thesis Defense in 434 PAN
Speaker: Michael Albright, University of Minnesota
Subject: Thermodynamics of Hot Hadronic Gases at Finite Baryon Densities
This is the public portion of Mr. Albright's thesis defense. His advisor is Joseph Kapusta
The universe is filled with protons and neutrons, which are themselves made of quarks and gluons. However, microseconds after the Big Bang, the universe was so hot and dense that quarks and gluons existed in other phases--first as a quark-gluon plasma, then as a hadron gas. Remarkably, these exotic phases of matter are created and studied experimentally in heavy-ion collisions at particle accelerators like RHIC at Brookhaven National Lab and the LHC at CERN. There is a strong effort underway to develop precision models of heavy-ion collisions which, combined with experimental data, will enable improved determination of many physical properties of quark-gluon matter. Recent years have seen significant improvements in modeling matter with zero net baryon density, which is relevant for RHIC, the LHC, and the early universe. However, there is growing interest in matter with a large net baryon density, which is relevant for neutron stars and future collider experiments. Hence, in this thesis we compute various thermodynamic properties of matter at large baryon densities. We first improve the popular hadron resonance gas equation of state (EoS) by including repulsive interactions, which are important at large baryon densities. Next, we develop crossover equations of state which smoothly transition from hadron gas models at low energy densities to a quark-gluon plasma EoS at high energy densities. We then compute net baryon number fluctuations and compare them to measurements from the STAR Collaboration at RHIC. We find that fluctuations freeze out long after chemical reactions do. Finally we develop a relativistic quasiparticle kinetic theory of hadron gases at large baryon densities. This includes interactions via scalar and vector mean fields in a thermodynamically consistent way. We then derive formulas for the shear and bulk viscosity and thermal conductivity, which are interesting quantities that influence experimental observables.
Tuesday, November 24th 2015
12:00 pm:
Speaker: Chick Woodward, Minnesota Institute for Astrophysics
Subject: Exoplanets
Wednesday, November 25th 2015
10:10 am:
Topic to be announced.
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
Thanksgiving - There will be no seminar this week.
There will be no seminar this week.
Thursday, November 26th 2015
12:05 pm:
Speaker: No Journal Club - Thanksgiving holiday
Speaker: No Colloquium today due to Thanksgiving Holiday
Friday, November 27th 2015
11:15 am:
There will be no seminar this week.
There will be no seminar this week.
12:30 pm:
There will be no seminar this week: University closed for Thanksgiving
2:30 pm:
Speaker: No colloquium. U of M closed for Thanksgiving holiday.
No Colloquium: Thanksgiving Break
There will be no seminar this week.
Monday, November 30th 2015
12:45 pm:
Speaker: Tony Young, University of Minnesota
Subject: Density slope oscillations in the central regions of galaxy and cluster-sized systems
The distribution of matter in halos has a variety of consequences ranging from the ability to verify dark matter models through structure growth to holding clues about the physical processes shaping and forming halos and the galaxies within. We present data from two papers describing the central regions of early type galaxies and galaxy clusters and along with dark matter N-body simulations, analyze and comment on "oscillations" present in central regions of their radial, total density profiles.
Tuesday, December 1st 2015
12:00 pm:
Speaker: Bart Van Compernolle, BaPSF, UCLA
Subject: Energetic electrons and whistler waves in laboratory plasmas
4:30 pm:
CM Journal Club in PAN 210
Speaker: Chun Chen
Subject: Introduction to anyon models
The reference is Parsa Bonderson, Caltech PhD Thesis Chapter 2 (2007)
Wednesday, December 2nd 2015
10:10 am:
To be announced.
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
Speaker: Alex Levchenko, University of Wisconsin
Subject: Anomalous Hall Effect Generalities - The Case of Kondo Topological Insulators
We calculate the anomalous Hall conductivity of surface states on three dimensional topological Kondo insulators with cubic symmetry and multiple Dirac cones. We treat a generic model in which the Fermi velocity, the Fermi momentum and the Zeeman energy in different pockets may be unequal and in which the microscopic impurity potential is short ranged on the scale of the smallest Fermi wavelength. Our calculation of AHE to the zeroth (i.e. leading) order in impurity concentration is based on the Kubo-Smrcka-Streda diagrammatic approach. It also includes certain extrinsic skew scattering contributions with a single cross of impurity lines, which are of the same order in impurity concentration. We discuss various special cases of our result and the experimental relevance of our study in the context of recent hysteretic magnetotransport data in SmB6 samples.
Faculty Host: Vlad Pribiag
Speaker: Rik Gran, University of Minnesota, Duluth
Subject: Multi-nucleon effects in neutrino-carbon interactions -- results from the MINERvA experiment.
Current and future neutrino oscillation experiments will depend on accurate neutrino interaction models in order to measure oscillation parameters and explore for CP violation. To support this, recently updated models for neutrino-nucleus interactions are compared to new cross sections measured by the MINERvA experiment. These results cover low momentum transfer events from quasi-elastic to resonance production, which are the most important for oscillation measurements. Discussion will include the impact on oscillation experiments and also the neutrino view of these multi-nucleon effects.
Thursday, December 3rd 2015
12:05 pm:
Speaker: Chris Nolting and Larry Rudnick
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Heather Wilkens, Manager of Business Development, ATA Engineering
Subject: Examining an Industrial Career Path in Physics
Refreshments to be served outside 230 SSTS after the colloquium.
Heather Wilson is Manager of Business Development at ATA Engineering
Researchers estimate that more PhD physicists in the US work in the private sector than in academia, so thinking through an industrial career path is a very useful exercise for current physics graduate students. In this talk, Dr. Wilkens will present recent career statistics of physicists in the private sector, along with the story of her industrial career after receiving her PhD from the U of MN Physics Department in 2003. She will also share thoughts on the industrial career paths chosen by her colleagues, and delve into the new and exciting careers she sees opening up for physicists in less traditional sectors.
Faculty Host: E. Dan Dahlberg
Friday, December 4th 2015
11:15 am:
Speaker: Ming Li, University of Minnesota
Subject: Early Time Pressure Isotropization in Relativistic Heavy Ion Collisions from Color Glass Condensate.
I will briefly review the Color Glass Condensate framework, which was proposed to describe the high energy limit of hadronic wave functions. Its classical realization, the McLerran-Venugopalan[MV] model will be used to study the early time dynamics of relativistic heavy ion collisions. Within the MV model, we solve the classical Yang-Mills equations analytically via a near-field(small-\tau) power series expansion. Energy-momentum tensor of the gluon field is calculated to all orders under a leading Q^2 approximation. Our calculations favor an early pressure isotropization at the time of the scale Q_s^{-1}.
Speaker: Tim Peterson, University of Minnesota
Subject: Electrical spin injection in ferromagnet/GaAs/AlGaAs 2DEG structures
Speaker: Francesco D'Eramo (UC Santa Cruz)
Subject: Freeze-In Dark Matter with Displaced Signatures at Colliders
Freeze-in is a general and calculable mechanism for dark matter production in the early universe. Assuming a standard cosmological history, such a framework predicts metastable particles with a lifetime generically too long to observe their decays at colliders. In this talk, I will consider alternative cosmologies with an early matter dominated epoch, and I will show how the observed abundance of dark matter is reproduced only for shorter lifetimes of the metastable particles. Famous realization for such a cosmology are moduli decays in SUSY theories and inflationary reheating. Remarkably, for a large region of the parameter space the decay lengths are in the displaced vertex range and they can be observable at present and future colliders. I will conclude with an example of DFSZ SUSY theories where this framework is realized.
2:30 pm:
Speaker: Amit Kashi, MIfA
Subject: Supernova Impostors - The Giant Eruptions of Very Massive Stars
The "supernova impostors" resemble the appearance of a true supernova, but
rather than a terminal explosion of a star, the impostors appear to be massive stars that have undergone a giant eruption and survived. Several of these have energetics comparable to true supernovae, and may be analogous to the Great Eruption of the massive star Eta Carinae in the 1800s.
I discuss observed characteristics of SN impostors and what is presently known and unknown about them. I present new numerical simulations following the recovery of the star from a giant eruption. The numerical results show that the eruption is a runaway event that causes huge mass loss from the star. The simulated star develops inner pulsations that further drive stellar wind with strong mass loss, as observed in erupting objects of that kind. It takes the star a few centuries to recover from the eruption and return to equilibrium.
Speaker: Peter Distelzweig, University of St. Thomas
Subject: Method and Morals in William Harvey's Philosophical Anatomy
Refreshments served at 3:15 p.m.
In the preface to his 1655 De Corpore, Thomas Hobbes identified William Harvey as the first to discover and demonstrate the science of the human body, and set him alongside Copernicus and Galileo as a founder of genuine natural science. Hobbes says Harvey is the only man he knows who, conquering envy, established a new doctrine in his own lifetime. Harvey himself frames his De motu cordis (1628) as an effort, both methodologically sound and morally upright, to convince “studious, good, and honest men” despite the ill will and machinations of those with biased minds. Drawing on his anatomy lecture notes, I first unpack Harvey’s understanding of right method in “philosophical anatomy.” I then trace how this understanding shapes Harvey’s argumentation in the De motu cordis, including its moral valence.
Speaker: Vlad Pribiag, University of Minnesota
Subject: Quantum transport in novel materials
Monday, December 7th 2015
12:45 pm:
There will be no seminar this week so that the group can attend Dr. Szalay's lecture: https://www.cs.umn.edu/activity/talks/colloquia/december-7-2015-1115am
Tuesday, December 8th 2015
12:00 pm:
Speaker: Yan Song, University of Minnesota
Subject: Charged Particle Acceleration in Cosmic Plasmas: Theory (Part 1).
There will also be several AGU practice talks during the time slot, see abstract for details.
AGU Practice Talks:
Scott Thaller,University of Minnesota
"The role of the large scale convection electric field in erosion of the plasmasphere during moderate and strong storms"
Charles McEachern, University of Minnesota
"Parametric Survey of Inner Magnetosphere FLRs in the Pc4 Range"
4:30 pm:
CM Journal Club in PAN 210
Speaker: Mengqun Li
Subject: Time-reversal asymmetry without local moments via directional scalar spin chirality
Quantum phases of matter that violate time-reversal symmetry invariably develop local spin or orbital moments in the ground state, such as ferromagnets, spin density waves, electrons in loop current phases, etc. A common property is that time reversal symmetry is restored as soon as the moments melt. However, there may exist a phase of matter that violates time-reversal symmetry but has no moments, which is called the “directional scalar spin chiral order” (DSSCO) from Ref. [1]. It can be obtained by melting the spin moments in a magnetically ordered phase but retaining residual broken time-reversal symmetry.
Outline of my talk:
(1) Introduction to time-reversal symmetry and several examples
(2) Directional scalar spin chiral order(DSSCO) in 1D, 2D and 3D
(3) Experimental detection and application to the cuprates (if time allows)
Reference:
[1]:Pavan Hosur. arXiv:1510.00975
Wednesday, December 9th 2015
10:10 am:
Biophysics Seminar in 120 PAN
Speaker: Jon Sachs, University of Minnesota
Subject: To be announced.
1:25 pm:
Speaker: Konstantin Reich, UMN
Subject: How many electrons make a semiconductor nanocrystal film metallic
For films of semiconductor nanocrystals to achieve their potential as novel,
low-cost electronic materials, a better understanding of their doping to tune
their conductivity is required. So far, it not known how many dopants will
turn a nanocrystal film from semiconducting to metallic. In bulk
semiconductors, the critical concentration of electrons at the metal-
insulator transition is described by the famous Mott criterion. We show
theoretically that in a dense NC film, where NCs touch each other by small
facets, the concentration of electrons N at the metal-insulator transition
satisfies the condition: N r^3 = 0.3, where r is a radius of contact facets.
In the accompanying experiments, we investigate the conduction mechanism in
films of phosphorus-doped, ligand-free silicon nanocrystals. At the largest
electron concentration achieved in our samples, which is half the predicted
N, we find that the localization length of hopping electrons is close to three
times the nanocrystals diameter, indicating that the film approaches the
metal-insulator transition.
Thursday, December 10th 2015
08:00 am:
Untitled in Physics
To be announced.
09:30 am:
Thesis Defense in PAN 120
Speaker: Xin Li, University of Minnesota
Subject: Phenomenology of Hadrons Containing Heavy Quarks
This is the public portion of Mr. Li's thesis defense. His adviser is Mikhail Voloshin.
Recent experiments have brought us new surprises about old quarkonium system. A series of exotic resonances are discovered in electron-positron colliders and new hadronic processes are measured. I will discuss some aspects of those new experimental results. The heavy quark spin symmetry and QCD-based method will be used to understand those results.
12:05 pm:
Speaker: Melanie Beck and Wlodek Kluzniak (Copernicus Astronomical Center, Warsaw, Poland)
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
Speaker: Cancelled--No Colloquium today
Speaker: Ohad Shpielberg, Technion
Subject: Le Chatelier principle for out of equilibrium and boundary driven systems : application to dynamical phase transitions.
A stability analysis of out of equilibrium and boundary driven systems is presented. It is performed in the framework of the hydrodynamic macroscopic fluctuation theory and assuming the additivity principle whose interpretation is discussed with the help of a Hamiltonian description. An extension of Le Chatelier principle for out of equilibrium situations is presented which allows to formulate the conditions of validity of the additivity principle. Examples of application of these results in the realm of classical and quantum systems are provided.
Friday, December 11th 2015
11:15 am:
Speaker: Chen Hou, University of Minnesota
Subject: The ODT Model Of Photospheric Radius Expansion Bursts
A Type-I X-ray burst is the thermonuclear runaway that occurs on the surface of a neutron star in a binary system. Studies on these bursts are of great importance for understanding neutron stars, nuclear reactions and the equation of state of dense matter at low temperature. I will discuss a subset of X-ray bursts, photospheric radius expansion bursts, that is powerful to lift up the photosphere of the star with the simulations based on a new 1D turbulence model, ODT. The model is different in that the turbulent motion is implemented according to a stochastic process and an eddy event is represented by a measure-preserving map. I will compare the light curve, abundances, and turbulent motion development with a KEPLER model in which the traditional mixing length theory is applied. The light curves of both models will be compared with observational data.
Speaker: Taher Ghasimakbari, University of Minnesota
Subject: Simulations of Diblock Copolymers
Speaker: Gilly Elor (MIT)
Subject: Hidden Sector Dark Matter: The Galactic Center Gamma-Ray Excess and Indirect Detection Constraints.
If dark matter is embedded in a non-trivial hidden sector, it may annihilate and decay to lighter hidden sector states which subsequently decay to Standard Model particles. While remaining agnostic to the details of the hidden sector model, our framework - with annihilations followed by cascading hidden sector decays - captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, electron-positrons, and antiprotons) relative to the case of dark matter annihilating directly to Standard Model particles. I will detail how such scenarios can explain the apparent excess in GeV gamma-rays identified in the central Milky Way, while evading bounds from direct detection experiments. Additionally I will describe how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. In particular I will describe an investigation of the limits from the cosmic microwave background by Plank, the Fermi measurements of photons from the Milky Way Dwarf Spheroidal Galaxies, and positron data from AMS-02. Generally the bound from the Fermi dwarfs is the most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence of the details of the hidden sector cascade.
2:30 pm:
Speaker: Robert Benjamin, U Wisconsin-Whitewater
Subject: Two and a Half New Things about the Milky Way Galaxy
Galactic structure is a topic that is so old that it’s become new again. After a brief review of history and recent events in Galactic structure. I will discuss two (and a half) new results about the overall structure of the Galaxy that come principally from two on-going Galactic surveys at Wisconsin: GLIMPSE and WHAM. GLIMPSE (Galactic Legacy Infrared Midplane Survey Extraordinaire) is a high angular resolution (arcsec) mid-infrared survey of the Galactic midplane using the Spitzer Space Telescope. From this survey, I will present some new results from this survey on the non-axisymmetric structure of the stellar disk. WHAM is a lower angular resolution (degree) velocity-resolved H-alpha survey of the diffuse ionized gas in the Galaxy (and beyond). From this survey, I will present some new information about our local solar neighborhood and a potential large scale magnetized outflow. (The reason for the non-integer number of discoveries is that one of the things we’ve found about the Milky Way is known to some, but not generally accepted by all.)
Speaker: Nicholas Buchanan, History of Science and Technology, University of Minnesota
Subject: Tanked: On Keeping This Alive in Places They Shouldn't Be
Refreshments served at 3:15 p.m.
In this talk, Dr. Buchanan will discuss the history of two tanks, each of which was designed to keep organisms alive in places where they otherwise would have perished. These artificial environments—aquaria beginning in the mid-19th century and spacecraft in the mid 20th—together offer a window onto changing perceptions about the human ability to know the natural world and to use that knowledge to control, manipulate, and even replicate it. In both cases, scientists, engineers, and enthusiasts used changing knowledge about the earth and its inhabitants to create technologies that were meant to be “an imitation of the means employed by nature herself” (to use the words of a Victorian aquarian), ranging from table-top jars to large institutional aquaria, from single-person capsules to plans for permanent human colonies in space. I’ll argue that building artificial environments was an important activity from which scientists, engineers, the public, and policy-makers learned about the systemic complexities of nature. What’s more, the difficult task of making artificial environments that could actually support life for long periods, and the ease with which these could be “broken,” highlighted the fragility of nature and its vulnerability to human intervention.
Speaker: Prisca Cushman, University of Minnesota
Subject: Searching For Dark Matter - SuperCDMS Experiment
7:00 pm:
Bell Museum Social in Bell Museum of Natural History
Speaker: Larry Rudnick, University of Minnesota
Subject: The Biggest Things in the Universe
Monday, December 14th 2015
12:45 pm:
Speaker: Kohta Murase, Penn State University
Subject: Mysteries of Cosmic High-Energy Neutrinos
The origin of cosmic high-energy neutrinos is a new mystery in astroparticle physics. We discuss possible scenarios and general implications that have been obtained so far, showing the importance of multi-messenger data. Then, we summarize open questions and future prospects.
Tuesday, December 15th 2015
12:00 pm:
There will be no seminar this week.
4:30 pm:
CM Journal Club in PAN 210
There will be no JC this week.
Wednesday, December 16th 2015
08:00 am:
10:10 am:
Speaker: To be announced
10:10 am:
Biophysics Seminar in 120 PAN
There will be no seminar this week.
1:25 pm:
Speaker: Nadya Mason, University of Illinois
Subject: The Emergence of Superconductivity in Inhomogeneous, Mesoscopic Systems
Although low-dimensional, inhomogeneous superconductors have been intensely studied, the nature of the onset of superconductivity in these systems is still largely unknown. In this talk I will present transport measurements on mesoscopic disks of granular, inhomogeneous Nb, where the superconducting transition temperature is determined as a function of disk diameter. We observe an unexpected suppression of superconductivity at micron diameters, length scales that are considerably longer than the coherence length of Nb. This suppression does not appear in large-scale films, and cannot be explained by single-grain small-size effects. By considering the diameter-dependence of the transition, as well as observations of strong fluctuations in the transition temperature as disk diameters decrease, we are able to explain this long length scale dependence by an extremal-grain model, where superconducting order first appears in unusually large grains and, due to proximity coupling, spreads to other grains. The extremal-grain onset of superconductivity has not previously been observed experimentally, and explains how superconductivity can emerge in granular or inhomogeneous superconductors.
Faculty Host: Vlad Pribiag
To be announced.
Thursday, December 17th 2015
08:00 am:
3:35 pm:
Physics and Astronomy Colloquium in 230 STSS/Bruininks Hall
There will be no colloquium this week.
Friday, December 18th 2015
11:15 am:
To be announced.
There will be no seminar this week.
There will be no seminar this week.
2:30 pm:
There will be no colloquium this week.
There will be no colloquium this week.
No seminar this week.
Wednesday, December 23rd 2015
4:30 pm:
Thursday, December 24th 2015
08:00 am:
Friday, December 25th 2015
08:00 am:
The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6572580337524414, "perplexity": 2414.312055950702}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560628001138.93/warc/CC-MAIN-20190627115818-20190627141818-00373.warc.gz"} |
https://nyuscholars.nyu.edu/en/publications/unusual-proton-transfer-kinetics-in-water-at-the-temperature-of-m | # Unusual Proton Transfer Kinetics in Water at the Temperature of Maximum Density
Emilia V. Silletta, Mark E. Tuckerman, Alexej Jerschow
Research output: Contribution to journalArticlepeer-review
## Abstract
Water exhibits numerous anomalous properties, many of which remain poorly understood. One of its intriguing behaviors is that it exhibits a temperature of maximum density (TMD) at 4 °C. We provide here new experimental evidence for hitherto unknown abrupt changes in proton transfer kinetics at the TMD. In particular, we show that the lifetime of OH- ions has a maximum at this temperature, in contrast to hydronium ions. Furthermore, base-catalyzed proton transfer shows a sharp local minimum at this temperature, and activation energies change abruptly as well. The measured lifetimes agree with earlier theoretical predictions as the temperature approaches the TMD. Similar results are also found for heavy water at its own TMD. These findings point to a high propensity of forming fourfold coordinated OH- solvation complexes at the TMD, underlining the asymmetry between hydroxide and hydronium transport. These results could help to further elucidate the unusual properties of water and related liquids.
Original language English (US) 076001 Physical Review Letters 121 7 https://doi.org/10.1103/PhysRevLett.121.076001 Published - Aug 13 2018
## ASJC Scopus subject areas
• Physics and Astronomy(all)
## Fingerprint
Dive into the research topics of 'Unusual Proton Transfer Kinetics in Water at the Temperature of Maximum Density'. Together they form a unique fingerprint. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8761487007141113, "perplexity": 3901.286743927351}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882571090.80/warc/CC-MAIN-20220809215803-20220810005803-00118.warc.gz"} |
https://www.semanticscholar.org/paper/Improved-Sobolev-embeddings%2C-profile-decomposition%2C-Palatucci-Pisante/0a99d73c566fb41cb0acc5b136f498c8c29c57cb | # Improved Sobolev embeddings, profile decomposition, and concentration-compactness for fractional Sobolev spaces
@article{Palatucci2013ImprovedSE,
title={Improved Sobolev embeddings, profile decomposition, and concentration-compactness for fractional Sobolev spaces},
journal={Calculus of Variations and Partial Differential Equations},
year={2013},
volume={50},
pages={799-829}
}
• Published 24 February 2013
• Mathematics
• Calculus of Variations and Partial Differential Equations
We obtain an improved Sobolev inequality in $$\dot{H}^s$$H˙s spaces involving Morrey norms. This refinement yields a direct proof of the existence of optimizers and the compactness up to symmetry of optimizing sequences for the usual Sobolev embedding. More generally, it allows to derive an alternative, more transparent proof of the profile decomposition in $$\dot{H}^s$$H˙s obtained in Gérard (ESAIM Control Optim Calc Var 3:213–233, 1998) using the abstract approach of dislocation spaces…
Weighted inequalities for the fractional Laplacian and the existence of extremals
• Mathematics
Communications in Contemporary Mathematics
• 2019
In this paper, we obtain improved versions of Stein–Weiss and Caffarelli–Kohn–Nirenberg inequalities, involving Besov norms of negative smoothness. As an application of the former, we derive the
The concentration-compactness principle for fractional order Sobolev spaces in unbounded domains and applications to the generalized fractional Brezis–Nirenberg problem
• Mathematics
Nonlinear Differential Equations and Applications NoDEA
• 2018
In this paper we extend the well-known concentration-compactness principle for the Fractional Laplacian operator in unbounded domains. As an application we show sufficient conditions for the
Concentration-compactness principle for nonlocal scalar field equations with critical growth
• Mathematics
• 2017
Multiple positive solutions for nonlinear critical fractional elliptic equations involving sign-changing weight functions
• Mathematics
• 2016
AbstractIn this article, we prove the existence and multiplicity of positive solutions for the following fractional elliptic equation with sign-changing weight functions:
Existence and multiplicity results for fractional p-Kirchhoff equation with sign changing nonlinearities
• Mathematics
• 2015
Abstract In this paper, we show the existence and multiplicity of nontrivial non-negative solutions of the fractional p-Kirchhoff problem M∫ ℝ 2n |u(x)-u(y)| p |x-y| n+ps d x d y(-Δ) p s u=λf(x)|u|
Asymptotic behavior of Palais–Smale sequences associated with fractional Yamabe-type equations
• Mathematics
• 2015
In this paper, we analyze the asymptotic behavior of Palais-Smale sequences associated to fractional Yamabe-type equations on an asymptotically hyperbolic Riemannian manifold. We prove that
The existence and multiplicity of the normalized solutions for fractional Schrödinger equations involving Sobolev critical exponent in the L2-subcritical and L2-supercritical cases
• Mathematics
• 2022
Abstract This paper is devoted to investigate the existence and multiplicity of the normalized solutions for the following fractional Schrödinger equation: (P) ( − Δ ) s u + λ u = μ ∣ u ∣ p − 2 u + ∣
Ground state solutions and decay estimation of Choquard equation with critical exponent and Dipole potential
• Mathematics
Discrete and Continuous Dynamical Systems - S
• 2022
In this paper, we study a class of Choquard equations with critical exponent and Dipole potential. We prove the existence of radial ground state solutions for Choquard equations by using the refined
## References
SHOWING 1-10 OF 82 REFERENCES
The concentration-compactness principle in the Calculus of Variations
Description du défaut de compacité de l’injection de Sobolev. ESAIM: Control, Optimisation and Calculus of Variations
• 1998
Lions: The concentration-compactness principle in the calculus of variations. The limit case, part 2
• Rev. Mat. Iberoamericana
• 1985
Oru: Inégalités de Sobolev précisées. Séminaire sur lesles´lesÉquations aux Dérivées Partielles
• ´ Ecole Polytech., Palaiseau., Exp. no. IV
• 1996
Wheeden: Weighted Inequalities for Fractional Integrals on Euclidean and Homogeneous Spaces
• Amer. J. Math
• 1992
Lions: The concentration-compactness principle in the calculus of variations. The limit case, part 1
• Rev. Mat. Iberoamericana
• 1985
Best constants in Sobolev inequalities | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9437255263328552, "perplexity": 2182.53783325501}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656103033816.0/warc/CC-MAIN-20220624213908-20220625003908-00109.warc.gz"} |
http://www.maa.org/publications/periodicals/mathematics-magazine/mathematics-magazine-june-2004 | # Mathematics Magazine - June 2004
### ARTICLES
Falling Down a Hole through the Earth
Andrew J. Simoson
171-189
Drop a magic pebble into the rotating Earth, allowing it to fall, drilling its own hole without resistance. With respect to a stationary reference frame, the pebble's path is an ellipse whose center is the center of the Earth (a result proved by Newton) and whose nearest approach to the Earth's center is over 300 km when the pebble is dropped at the Equator. With respect to the rotating reference frame of the Earth, the pebble's hole is a star-shaped figure, an analysis of which leads naturally into determining the pebble's dynamic distance from straight down and into a discussion of the early pebble-drop experiments of Galileo and Hooke. When hypothetically changing the Earth's gravity field, the resultant paths twist as precessing ellipses and raise some natural questions such as why the Spirograph Nebula looks like a tangle of pebble holes falling through the gravitational field of the dust cloud.
### PROOF WITHOUT WORDS
Euler’s Arctangent Identity
Rex H. Wu
189
The identity arctan(1/x) = arctan(1/(x+y)) + arctan(y/(x(x+y)+1) is one of many elegant arctangent identities discovered by Leonard Euler. He employed them in the computation of π.
Upper Bounds on the Sum of Principal Divisors of an Integer
Roger B. Eggleton and William P. Galvin
190-200
By the Fundamental Theorem of Arithmetic, a positive integer is uniquely the product of distinct prime-powers, which we call its principal divisors. For instance, the principal divisors of 90 are 2, 5, and 9. Brian Alspach recently asked for a nice proof that, apart from prime-powers, every odd integer greater than 15 is more than twice the sum of its principal divisors. Thus 21 is more than twice 3 plus 7, while 15 is almost, but not quite, twice 3 plus 5. How can Alspach’s observation be proved? To what extent is it true for even integers? For example, 20 is more than twice 4 plus 5, but 22 is less than twice 2 plus 11. When an integer has more than two principal divisors, are there stronger bounds on their sum? Part of the challenge is to find elegant bounds, the rest is to find elementary proofs.
PROOF WITHOUT WORDS
Every Octagonal Number Is the Difference between Two Squares
Roger B. Nelsen
200
A proof without words that the nth octagonal number is (2n-1)2-(n-1) 2. NOTES
Centroids Constructed Graphically
Tom M. Apostol and Mamikon A. Mnatsakanian
201-210
Two different methods are described for locating the centroid of a finite number of points in 1-space, 2-space, or 3-space by graphical construction, without using coordinates or numerical calculations. The first involves making a guess and forming a closed polygon. The second is an inductive procedure that combines centroids of two disjoint sets to determine the centroid of their union. For 1-space and 2-space, both methods can be applied in practice with drawing instruments or with computer graphic programs.
There Are Only Nine Finite Groups of Fractional Linear Transforms with Integer Coefficients
Gregory P. Dresden
211-218
Many of us recall fractional linear transforms (also known as Mobius transforms) from complex analysis, where we learned that these conformal functions map lines and circles to lines and circles (in the complex plane). In this article, we show that under composition, and using only integer coefficients, there are exactly nine distinct finite groups of fractional linear transforms. We establish the identical result for projective integer matrices of dimension two. The proof requires only a small amount of abstract algebra, and is entirely appropriate for upper-division math majors.
The One-dimensional Random Walk Problem in Path
Oscar Bolina
218-225
Path representations are very useful in physics and mathematics to transform hard algebraic problems into easier combinatorial ones, and this is true even of combinatorial problems themselves! We put the elementary problem of the random walk of a particle on the real line into a path representation form and use the geometry of the lattice paths to solve for the probability that the particle ends up at the origin given that it starts anywhere.
Why Some Elementary Functions Are Not Rational
Gabriela Chaves and José Carlos Santos
225-226
We prove, in an elementary way, that the restrictions to an open interval of certain elementary functions, such as the sine function or the exponential function, are not rational functions, and we do it by using the concept of degree of a rational function.
Another Look at Sylow's Third Theorem
Eugene Spiegel
227-232
Sylow's third theorem tells us that the number of p-Sylow subgroups in a finite group is congruent to 1 modulo p, and, in particular, there must exist p-Sylow subgroups of the group. But, to obtain Sylow's third theorem, it has been necessary to first show the existence of a p-Sylow subgroup. In this note we show how Mobius inversion can be used to obtain a generalized Sylow third theorem directly. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8270319700241089, "perplexity": 505.95537990012076}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802768285.15/warc/CC-MAIN-20141217075248-00153-ip-10-231-17-201.ec2.internal.warc.gz"} |
https://arxiv.org/abs/1101.0924 | astro-ph.SR
(what is this?)
# Title: Three-dimensional magnetic reconnection regimes: A review
Authors: D. I. Pontin
Abstract: The magnetic field in many astrophysical plasmas -- such as the Solar corona and Earth's magnetosphere -- has been shown to have a highly complex, three-dimensional structure. Recent advances in theory and computational simulations have shown that reconnection in these fields also has a three-dimensional nature, in contrast to the widely used two-dimensional (or 2.5-dimensional) models. Here we discuss the underlying theory of three-dimensional magnetic reconnection. We also review a selection of new models that illustrate the current state of the art, as well as highlighting the complexity of energy release processes mediated by reconnection in complicated three-dimensional magnetic fields.
Comments: Accepted for publication in Advances in Space Research. (Based on paper presented at 38th COSPAR meeting, Bremen, 2010.) Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Plasma Physics (physics.plasm-ph); Space Physics (physics.space-ph) DOI: 10.1016/j.asr.2010.12.022 Cite as: arXiv:1101.0924 [astro-ph.SR] (or arXiv:1101.0924v1 [astro-ph.SR] for this version)
## Submission history
From: David Pontin [view email]
[v1] Wed, 5 Jan 2011 10:13:48 GMT (2033kb,D) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.800285279750824, "perplexity": 5053.238367532502}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988720615.90/warc/CC-MAIN-20161020183840-00357-ip-10-171-6-4.ec2.internal.warc.gz"} |
http://www.komal.hu/verseny/2005-02/inf.e.shtml | Magyar Information Contest Journal Articles
Contest Rules Entry Form Problems Results Previous years
# Exercises and problems in InformaticsFebruary 2005
## Please read The Rules of the Problem Solving Competition.
### New exercises of sign I
I. 97. Let us think and experiment.
We fix a natural number n. Do there exist n real numbers such that their sum equals their product? Can a program be written that yields all these n-tuples? Further, if there is a solution, can we fix some of the n numbers in advance?
Your text file (i97.txt) containing the answers and comments and your program (i97.pas) giving the answers are to be submitted. (10 points)
I. 98. We are given a square lattice of size mxn (with positive integers m and n). Square based right prisms are put onto each square. The heights of the prisms are given by an mxn matrix.
Write your program that displays this construction in perspective view together with its front and side views. In demo mode your program can specify the heights of the prisms, but in user mode the program should read these data from the input, then display the corresponding figures.
The program (i98.pas) is to be submitted. (10 points)
Remark. A continuation of this problem will appear next month.
I. 99. We are thirsty but fortunately there is a drink machine that accepts coins.
In the first few cells of the third row of an Excel sheet existing coins are listed in descending order.
Prepare a sheet so that one can enter the cost of a drink (being a natural number) into the first cell of the first row, then the number of necessary coins for that drink appears in the fourth row - just below the corresponding coin values.
However, there is a restriction, namely, one should first use up coins of the highest value, as many as possible, then this principle should be applied repeatedly to lower valued coins to make up the desired amount.
Your sheet (i99.xls) is to be submitted. (10 points)
Contestants are kindly asked to consider the following issues. Interpretation of the problems as well as devising and implementing the necessary routines (including the layout of the input and output) form integral parts of the solution unless we specify otherwise. We accept every reasonable interpretation, however, the points awarded can depend on your interpretation, for example, the restrictions you needed to impose in order to get a solution in reasonable time.
Secondly, it would be unfair if we gave extra information to contestants inquiring in emails, hence they are asked not to send us such requests in the future, we will reply to none of them.
Finally, a general remark: there is no bad problem as such - of course it may sometimes happen that the solution set is empty, or the required figure or data set does not exist. Questions of this type frequently occur in practice: their quick identification (possibly with appropriate proofs) can be highly valuable and often leads to reformulation of the problem or changing the viewpoint.
### New problem of sign S
S. 6. There are n people arriving at a stadium to watch a match. We know in advance who is hostile to whom among these people (hostility is assumed to be mutual). Our task is to divide these people into two groups: one group should take their seats on the left, while the other one on the right stand of the stadium in such a way that there should be no hostility among people in the same group. If such division is not possible, then we should find a proof''.
A proof should consist of a list of odd numbered people such that each of them is hostile to the previous and the next person in the list, moreover, the last person is hostile to the first one. (In fact, these people can not be divided into two according to the requirements above.)
Your program should read data from the standard input. People are numbered from 1 to n. The first row of the input is n, then two numbers will follow in each subsequent row - describing hostile pairs.
If an appropriate division is possible, then your program should display the result on the standard output containing all the numbers of those people who should take their seats on the left stand of the stadium (the 1-st person should be seated on the left). On the other hand, if a solution to the seating problem can not be found, then your program should display on the standard output the proof mentioned above, that is, numbers of those odd numbered people.
We can suppose that n is at most 65 000 and each person is hostile to at most 200 other fans. Please pay attention to the format of submission as specified by the rules of contest (for example, you should comment on the code, further, programs in Delphi and other exotic'' languages will be disqualified). (10 points)
### Deadline: 15 March 2005
Our web pages are supported by: Morgan Stanley | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5555660724639893, "perplexity": 613.7669085385687}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818693459.95/warc/CC-MAIN-20170925220350-20170926000350-00086.warc.gz"} |
https://mathoverflow.net/questions/370029/a-packing-ball-problem-verify-lower-bound-on-gaussian-width-of-sparse-ball | # A packing ball problem: verify lower bound on Gaussian width of sparse ball
Note: This should be a geometry problem about packing balls. All the necessary probability pre-requisite is given below.
Consider a set of sparse vectors: $$T_{n,s}:=\{x\in \mathbb{R}^n:\|x\|_0 \le s, \|x\|_2\le1\}$$ where $$\|x\|_0 \le s$$ simply means there can be at most $$s$$ non-zero coordinates. Gaussian width of a set of vectors is defined as $$w(T)=\sup_{x\in T}\langle x, g\rangle$$ where $$g\sim \mathcal{N}(0,I_n)$$.
The claim is that $$w(T_{n,s})\ge c\sqrt{s\log{(2n/s)}}.$$
The author suggests that we can use so-called Sudakov inequality which states that $$w(T)\ge \epsilon\sqrt{\log P(T,d,\epsilon)}$$ where $$P(T,d,\epsilon)$$ is ANY valid $$\epsilon-$$packing of $$T_{n,s}$$. A $$\epsilon-$$packing is a subset of $$T$$ such that for any pair of points in the packing has distance larger than $$\epsilon>0$$.
A partial result of mine: I considered packing $$T_{n,s}$$ with the following: there are $$\binom{n}{s}\ge (n/s)^s$$ ways to choose the k nonzero coordinates out of n coordinates. For each choice, we consider assigning all s non-zero coordinates as $$\sqrt{1/s}.$$ This way any pair of points has distance at least $$\epsilon=\sqrt{2}/\sqrt{s}$$ (because they have at least two non-overlapping coordinates). This packing gives $$w(T)\ge \frac{\sqrt{2}}{\sqrt{s}}\sqrt{s \log (2n/s)}$$. I'm still missing $$\sqrt{s}$$ factor.
How can I choose the packing more optimally to recover this $$\sqrt{s}$$ factor?
Thank you!
• The usual trick: you have ${n\choose s}$ vectors of your type and for each vector there are at most ${s\choose s/2}{n\choose s/2}$ vectors of your type that overlap with a given vector in at least $s/2$ coordinates. Thus, doing the greedy algorithm, you can choose at least ${n\choose s}/[{n\choose s/2}{s\choose s/2}]\ge 2^{-s}[\frac{n-s}{s}]^{s/2}$ vectors at constant distance from each other, For $s<n/10$ this crude bound gives the desired result and then you just use the monotonicity of the width. Aug 24, 2020 at 20:36
• Thank you for the insight. Aug 24, 2020 at 20:49 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 20, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9776571989059448, "perplexity": 246.43322664818237}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662529538.2/warc/CC-MAIN-20220519141152-20220519171152-00160.warc.gz"} |
https://ameriflux.lbl.gov/community/publication/climatology-of-the-low-level-jet-at-the-southern-great-plains-atmospheric-boundary-layer-experiments-site/ | # Climatology Of The Low-Level Jet At The Southern Great Plains Atmospheric Boundary Layer Experiments Site
• Sites: US-Wlr
• Song, J., Liao, K., Coulter, R. L., Lesht, B. M. (2005) Climatology Of The Low-Level Jet At The Southern Great Plains Atmospheric Boundary Layer Experiments Site, Journal Of Applied Meteorology, 44(10), 1593-1606. https://doi.org/10.1175/jam2294.1
• Funding Agency: —
• A unique dataset obtained with combinations of minisodars and 915-MHz wind profilers at the Atmospheric Boundary Layer Experiments (ABLE) facility in Kansas was used to examine the detailed characteristics of the nocturnal low-level jet (LLJ). In contrast to instruments used in earlier studies, the ABLE instruments provide hourly, high-resolution vertical profiles of wind velocity from just above the surface to approximately 2 km above ground level (AGL). Furthermore, the 6-yr span of the dataset allowed the examination of interannual variability in jet properties with improved statistical reliability. It was found that LLJs occurred during 63% of the nighttime periods sampled. Although most of the observed jets were southerly, a substantial fraction (28%) was northerly. Wind maxima occurred most frequently at 200–400 m AGL, though some jets were found as low as 50 m, and the strongest jets tended to occur above 300 m. Comparison of LLJ heights at three locations within the ABLE domain and at one location outside the domain suggests that the jet is equipotential rather than terrain following. The occurrence of southerly LLJ varied annually in a way that suggests a connection between the tendency for jet formation and the large-scale circulation patterns associated with El Niño and La Niña, as well as with the Pacific decadal oscillation. Frequent and strong southerly jets that transport moisture downstream do not necessarily lead to more precipitation locally, however. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8597947955131531, "perplexity": 5238.385406843859}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662521152.22/warc/CC-MAIN-20220518052503-20220518082503-00139.warc.gz"} |
https://ask.sagemath.org/question/36557/vertical-view-plot3d/ | # Vertical view plot3d edit
Is there any way to set the vertical view in plot3d? For example I want to plot sqrt(x^2+ y^2). I know how to set the x and y ranges but I only want the z axis to go from say 0 to 3. Zmin and zmax do not seem to do anything.
edit retag close merge delete
Sort by » oldest newest most voted
Since the surface is determined by the independent variables, you can limit their domains to limit the height of the surface:
var('x y z')
limit = sqrt(9/2)
plot3d(sqrt(x^2+ y^2), (x,-limit,limit), (y,-limit,limit))
Here's a live example.
And if you want to set limits for each variable independently, use implicit_plot3d:
var('x y z')
implicit_plot3d(sqrt(x^2+ y^2)-z, (x,-5,5), (y,-5,5), (z,0,3))
Another live example.
more
Thanks for your reply! However, not quite what I'm looking for. Unfortunately I now realize that I was not very clear in my question! Basically I want that figure to look exactly like what it's supposed to look like (i.e., a cone). I can see that the cone is there, but when I'm teaching this stuff to students who have never seen it before, they're going to look at that figure and say "that's not a cone" due to the top "curves". So, I want to actually have the independent variables generate larger values of Z than the values of Z that I show (basically, I want to chop the top part of that view so that it now actually does look like a standard cone). Is there a way to do this?
( 2017-02-11 11:10:34 -0500 )edit
( 2017-02-11 17:58:43 -0500 )edit | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.19843846559524536, "perplexity": 975.6864295310507}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-22/segments/1526794867841.63/warc/CC-MAIN-20180526170654-20180526190654-00552.warc.gz"} |
https://www.gradesaver.com/textbooks/math/calculus/calculus-with-applications-10th-edition/chapter-1-linear-functions-chapter-review-review-exercises-page-40/52 | ## Calculus with Applications (10th Edition)
$C(x)=30x+85$
In a linear cost function, of the form $C(x)=mx+b$, the $m$ represents the marginal cost and $b$ represents the fixed cost (zero units produced). The graph of C(x) passes through the points $(12, 445)$ and $(50, 1585).$ Slope: $m=\displaystyle \frac{1585-445}{50-12}=30$. Point-slope equation: $y-445=30(x-12)$ $y-445=30x-360\qquad/+445$ $y=30x+85$ or $C(x)=30x+85$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5113751292228699, "perplexity": 700.694046406603}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-26/segments/1529267863043.35/warc/CC-MAIN-20180619134548-20180619154548-00630.warc.gz"} |
http://mathoverflow.net/questions/128981/bounding-a-recursively-defined-sequence?answertab=votes | # Bounding a recursively defined sequence
I have a sequence $\lambda_0,\lambda_1,\ldots,$ which is defined recursively as
$$\lambda_0 = \frac{1}{2},$$
and
$$\lambda_{k+1} = \max_{\lambda\in [1,b]} \left(\frac{1}{2\lambda}\prod_{0\leq j\leq k}\left(\frac{\lambda-\lambda_j}{\lambda+\lambda_j}\right)^2\right), \qquad k\geq 0,$$
where $b>1$. I would like to find a relatively sharp upper bound for $\lambda_k$. Numerically, it seems that $\lambda_k$ is bounded by something like,
$$\lambda_k \leq \mathcal{O}\left(e^{-8k/\log(b)}\right).$$
For instance, the following very simple argument gives an upper bound that is very weak and I'm seeking techniques to do better:
Note that we have, for $k\geq 0$,
$$\lambda_{k+1} \leq \max_{\lambda\in[1,b]} \left(\frac{1}{2\lambda}\prod_{0\leq j\leq k-1}\left(\frac{\lambda-\lambda_j}{\lambda+\lambda_j}\right)^2\right)\max_{\lambda\in[1,b]}\left(\frac{\lambda - \lambda_k}{\lambda+\lambda_k}\right)^2\leq \lambda_k \left(\frac{b-1}{b+1}\right)^2$$
and hence,
$$\lambda_k \leq \left(\frac{b-1}{b+1}\right)^{2k}\lambda_0 =\frac{1}{2}\left(\frac{b-1}{b+1}\right)^{2k},\qquad k\geq0.$$
I think the usual name for this kind of definition is "recursive", not "implicit". An implicit definition would be of the form $f(\lambda_n)=0$, or $f(\lambda_n, \lambda_{n+1})=0$, etc. Each term in your sequence is defined quite explicitly as a function of the previous terms. Or did I miss something? – Goldstern Apr 28 '13 at 23:19
How about using the estimate for $\lambda_k$ that you obtained, when estimating the second $\max$? Currently, for estimates that $\max$ you bound $\lambda_k$ by $1$. It is the bootstrapping method popularized by Münchausen :-) – Boris Bukh Apr 29 '13 at 14:58 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.993122398853302, "perplexity": 276.03687616631316}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413558067214.90/warc/CC-MAIN-20141017150107-00295-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://www.groundai.com/project/the-effect-of-combined-magnetic-geometries-on-thermally-driven-winds-i-interaction-of-dipolar-and-quadrupolar-fields/ | Dipole and Quadrupole Mixing
# The Effect of Combined Magnetic Geometries on Thermally Driven Winds I: Interaction of Dipolar and Quadrupolar Fields
## Abstract
Cool stars with outer convective envelopes are observed to have magnetic fields with a variety of geometries, which on large scales are dominated by a combination of the lowest order fields such as the dipole, quadrupole and octupole modes. Magnetised stellar wind outflows are primarily responsible for the loss of angular momentum from these objects during the main sequence. Previous works have shown the reduced effectiveness of the stellar wind braking mechanism with increasingly complex, but singular, magnetic field geometries. In this paper, we quantify the impact of mixed dipolar and quadrupolar fields on the spin-down torque using 50 MHD simulations with mixed field, along with 10 of each pure geometries. The simulated winds include a wide range of magnetic field strength and reside in the slow-rotator regime. We find that the stellar wind braking torque from our combined geometry cases are well described by a broken power law behaviour, where the torque scaling with field strength can be predicted by the dipole component alone or the quadrupolar scaling utilising the total field strength. The simulation results can be scaled and apply to all main-sequence cool stars. For Solar parameters, the lowest order component of the field (dipole in this paper) is the most significant in determining the angular momentum loss.
magnetohydrodynamics (MHD) - stars: low-mass - stars: stellar winds, outflows - stars: magnetic field- stars: rotation, evolution
1\epstopdfsetup
outdir=./
## 1. Introduction
The spin down of cool stars () is a complex function of mass and age, as shown by the increasing number of rotation period measurements for large stellar populations (Barnes, 2003; Irwin & Bouvier, 2009; Barnes, 2010; Agüeros et al., 2011; Meibom et al., 2011; McQuillan et al., 2013; Bouvier et al., 2014; Stauffer et al., 2016; Davenport, 2017). Observed properties of these stars show a wide range of mass loss rates, coronal temperatures, field strengths and geometries, which all connect with stellar rotation to control the loss of angular momentum (Reiners & Mohanty, 2012; Gallet & Bouvier, 2013; Van Saders & Pinsonneault, 2013; Brown, 2014; Matt et al., 2015; Gallet & Bouvier, 2015; Amard et al., 2016; Blackman & Owen, 2016; See et al. in prep). Despite the wide range of interlinking stellar properties an overall trend of spin down with an approximately Skumanich law is observed at late ages; (Skumanich, 1972; Soderblom, 1983).
For Sun-like stars on the main sequence, the spin-down process is governed primarily by their magnetised stellar winds which remove angular momentum over the star’s lifetime. Parker (1958) originally posited that stellar winds must exist due to the thermodynamic pressure gradient between the high temperature corona and interplanetary space. Continued solar observations have constrained theoretical models for the solar wind to a high degree of accuracy (van der Holst et al., 2014; Usmanov et al., 2014; Oran et al., 2015). Recent models of the solar wind are beginning to accurately reproduce the energetics within the corona and explain the steady outflow of plasma into the Heliosphere (e.g. Grappin et al., 1983; Van der Holst et al., 2010; Pinto et al., 2016). The wind driving is now known to be much more complex than a thermal pressure gradient, with authors typically heating the wind through the dissipation of Alfvén waves in the corona. Other cool stars are observed with x-ray emissions indicating hot stellar coronae like that of the Sun (Rosner et al., 1985; Hall et al., 2007; Wright et al., 2004; Wolk et al., 2005). Similar stellar winds and wind heating mechanisms are therefore expected to exist across a range of Sun-like stars. Assuming equivalent mass loss mechanisms, results from the Solar wind are incorporated into more general stellar wind modelling efforts (e.g. Cohen & Drake, 2014; Alvarado-Gómez et al., 2016).
Detailed studies of wind driving physics remain computationally expensive to run, so are usually applied on a case-by-case basis. How applicabile the heating physics gained from modelling the Solar wind is to other stars still in question. With the reliability of such results even for the global properties of a given star in question, large parameter studies with simpler physics remain useful. A more general method can allow for parametrisations which are more appropriate to the variety of stellar masses and rotation periods found in observed stellar populations. Parker-type solutions remain useful for this due to their simplicity and versatility (Parker, 1965; Mestel, 1968; Sakurai, 1990; Keppens & Goedbloed, 1999). In these solutions, wind plasma is accelerated from the stellar surface and becomes transonic at the sonic surface. With the addition of magnetic fields the wind also become trans-alfvénic, i.e faster than the Alfvén speed, at the Alfvén surface. Weber & Davis (1967) showed for a one-dimensional magnetised wind that the Alfvén radius represented a lever arm for the spin-down torque. Since the introduction of this result, many researchers have produced scaling laws for the Alfvén radius (Mestel, 1984; Kawaler, 1988; Matt & Pudritz, 2008; Matt et al., 2012; Ud-Doula et al., 2009; Pinto et al., 2011; Réville et al., 2015a; Pantolmos. in prep) all of which highlight the importance of the magnetic field strength and mass loss rate in correctly parametrising a power law dependence. In such formulations, the mass loss rate is incourporated as a free parameter as the physical mechanisms which determines it are not yet completely understood. Measuring the mass loss rate from Sun-like stars is particularly difficult due to the wind’s tenuous nature and poor emission. Wood (2004) used Lyman- absorption from the interaction of stellar winds and their local interstellar medium to measure mass loss rates, but the method is model-dependent and only available for a few stars. Theoretical work from Cranmer & Saar (2011) predicts the mass loss rates from Sun-like stars, but it is uncertain if the physics used within the model scales correctly between stars. Therefore, parameter studies where the mass loss rate is an unknown parameter are needed.
In addition to the mass loss rate, the angular momentum loss rate is strongly linked with the magnetic properties of a given star. Frequently researchers assume the dipole component of the field to be the most significant in governing the global wind dynamics (e.g. Ustyugova et al., 2006; Zanni & Ferreira, 2009; Gallet & Bouvier, 2013; Cohen & Drake, 2014; Gallet & Bouvier, 2015; Matt et al., 2015; Johnstone et al., 2015). Zeeman Doppler Imaging (ZDI) studies (e.g. Morin et al., 2008; Petit et al., 2008; Fares et al., 2009; Vidotto et al., 2014b; Jeffers et al., 2014; See et al., 2015, 2016; Folsom et al., 2016; Hébrard et al., 2016; See et al., 2017), provide information on the large scale surface magnetic fields of active stars. Observations have shown stellar magnetic fields to be much more complex than simple dipoles, containing combinations of many different field modes. ZDI is a topographic technique typically decomposes the field at the stellar surface into individual spherical harmonic modes. The 3D field geometry can then be recovered with field extrapolation techniques using the ZDI map as an inner boundary. Several studies have considered how these observed fields affect the global wind properties. Typically used to determine an initial 3D field solution, then a magnetohydrodynamics code evolves this initial state in time until a steady state solution for the wind and magnetic field geometry is attained (e.g. Vidotto et al., 2011; Cohen et al., 2011; Garraffo et al., 2016b; Réville et al., 2016; Alvarado-Gómez et al., 2016; Nicholson et al., 2016; do Nascimento Jr et al., 2016). These works are less conducive to the production of semi-analytical formulations, as the principle drivers of the spin-down process are hidden within complex field geometries, rotation and wind heating physics.
A few studies show systematically how previous torque formulations depend on magnetic geometry using single modes. Réville et al. (2015a) explored thermally driven stellar winds with dipolar, quadrupolar and octupolar field geometries. They concluded that higher order field modes produce a weaker torque for the same field strength and mass loss, which is supported by results from Garraffo et al. (2016a). Despite these studies and works like them, only one study has systematic scaled the mass loss rate for a mixed field geometry field (Strugarek et al., 2014a). However, the aforementioned studies of the angular momentum loss from Sun-like stars have yet to address the systematic addition of individual spherical harmonic field modes.
Mixed geometry fields are observed within our closest star, the Sun, which undergoes a 11 year cycle oscillating between dipolar and quadrupolar field modes from cycle minimum to maximum respectively (DeRosa et al., 2012). Observed Sun-like stars also exhibit a range of spherical harmonic field combinations. Simple magnetic cycles are observed using ZDI, both HD 201091 (Saikia et al., 2016) and HD 78366 (Morgenthaler et al., 2012) show combinations of the dipole, quadrupole and octupole field modes oscillating similarly to the solar field. Other cool stars exist with seemingly stochastic changing field combinations (Petit et al., 2009; Morgenthaler et al., 2011). Observed magnetic geometries all contain combinations of different spherical harmonic modes with a continuous range of mixtures, it is unclear what impact this will have on the braking torque.
In this study we will investigate the significance of the dipole field when combined with a quadrupolar mode. We focus on these two field geometries, which are thought to contribute in anti-phase to the solar cycle and perhaps more generally to stellar cycles in cool stars. Section 2 covers the numerical setup with a small discussion of the magnetic geometries for which we develop stellar wind solutions. Section 3 presents the main simulation results, including discussion of the qualitative wind properties and field structure, along with quantitative parametrisations for the stellar wind torque. Here we also highlight the dipole’s importance in the braking, and introduce an approximate scaling relation for the torque. Finally in Section 4 we focus on the magnetic field in the stellar wind, first a discussion of the overall evolution of the flux, then a discussion of the open flux and opening radius within our simulations. Conclusions and thoughts for further work can then be found in Section 5. The Appendix contains a short note on the wind acceleration profiles of our wind solutions.
## 2. Simulation Method
### 2.1. Numerical Setup
This work uses the magnetohydrodynamics (MHD) code PLUTO (Mignone et al., 2007; Mignone, 2009), a finite-volume code which solves Riemann problems at cell boundaries in order to calculate the flux of conserved quantities through each cell. PLUTO is modular by design, capable of interchanging solvers and physics during setup. The present work uses a diffusive numerical scheme, the solver of Harten, Lax, and van Leer, HLL (Einfeldt, 1988), which allows for greater numerical stability in the higher strength magnetic field cases. The magnetic field solenoidality condition () is maintained using the Constrained Transport method (See Tóth (2000) for discussion).
The MHD equations are solved in a conservative form, with each equation relating to the conservation of mass, momentum and energy, plus the induction equation for magnetic field,
∂ρ∂t+∇⋅ρv = 0, (1) ∂m∂t+∇⋅(mv−BB+IpT) = ρa, (2) ∂E∂t+∇⋅((E+pT)v−B(v⋅B)) = m⋅a, (3) ∂B∂t+∇⋅(vB−Bv) = 0. (4)
Here is the mass density, is the velocity field, is the gravitational acceleration, is the magnetic field2, is the combined thermal and magnetic pressure, is the momentum density given by and is the total energy density. The energy of the system is written as , with representing the internal energy per unit mass of the fluid. is the identity matrix. A polytropic wind is used for this study, such that the closing equation of state takes the form where represents the polytropic index.
We assume the wind profiles to be axisymmetric and solve the MHD equations using a spherical geometry in 2.5D, i.e. our domain contains two spatial dimensions () but allows for 3D axisymetric solutions for the fluid flow and magnetic field using three vector components (). The domain extends from one stellar radius () out to with a uniform grid spacing in and a geometrically stretched grid in , which grows from an initial spacing of to at the outer boundary. The computational mesh contains grid cells. These choices allow for the highest resolution near the star, where we set the boundary conditions that govern the wind profile in the rest of the domain.
Initially a polytropic parker wind (Parker, 1965; Keppens & Goedbloed, 1999) with fills the domain, along with a super-imposed background field corresponding to our chosen magnetic geometry and strength. During the time-evolution, the plasma pressure, density, and poloidal components of the magnetic field () are held fixed at the stellar surface, whilst the poloidal components of the velocity () are allowed to evolve in response to the magnetic field (the boundary is held with and ). We then enforce the flow at the surface to be parallel to the magnetic field (). The star rotates as a solid body, with linearly extrapolated into the boundary and set using the stellar rotation rate ,
vϕ=Ω∗rsinθ+vp⋅Bp|Bp|2Bϕ, (5)
where the subscript “p” denotes the poloidal components () of a given vector. This condition enforces an effective rotation rate for the field lines which, in steady state ideal MHD, should be equal to the stellar rotation rate and conserved along field lines (Zanni & Ferreira, 2009; Réville et al., 2015a). This ensures the footpoints of the stellar magnetic field are correctly anchored into the surface of the star. The final boundary conditions are applied to the outer edges of the simulation, a simple outflow (zero derivative) is set at allowing for the outward transfer of mass, momenta and magnetic field, along with an axisymmetric condition along the rotation axis ( and ). Due to the supersonic flow properties at the outer boundary and its large radial extent compared with the location of the fast magnetosonic surface, any artefacts from the outer boundary cannot propagate upwind into the domain.
The code is run, following the MHD equations above, until a steady state solution is found. The magnetic fields modify the wind dynamics compared to the spherically symmetric initial state, with regions of high magnetic pressure shutting off the radial outflow. In this way, the applied boundary conditions allow for closed and open regions of flow to form (e.g Washimi & Shibata, 1993; Keppens & Goedbloed, 2000), as observed within the solar wind. In some cases of strong magnetic field small reconnection events are seen, caused by the numerical diffusivity of our chosen numerical scheme. Reconnection events are also seen in Pantolmos & Matt (in prep) and discussed within their Appendix. We adopt a similar method for deriving flow quantities in cases exhibiting periodic reconnection events. In such cases, once a quasi-steady state is established a temporal average of quantities such as the torque and mass loss are used.
Inputs for the simulations are given as ratios of characteristic speeds which control key parameters such as the wind temperature (), field strength () and rotation rate (). Where is the sound speed at the surface, is the Alfvén speed at the north pole, is the rotation speed at the equator, is the surface escape speed and is the keplerian speed at the equator. In this way, all simulations represent a family of solutions for stars with a range of gravities. As this work focuses on the systematic addition of dipolar and quadrupolar geometries, we fix the rotation rate for all our simulations. Matt et al. (2012) showed that the non-linear effects of rotation on their torque scaling can be neglected for slow rotators. They defined velocities as a fraction of the breakup speed,
f=vrotvkep∣∣∣r=R∗,θ=π/2=Ω∗R3/2∗(GM∗)1/2. (6)
The Alfvén radius remains independent of the stellar spin rate until , after which the effects of fast rotation start to be important. For this study a solar rotation rate is chosen (), which is well within the slow rotator regime. We set the temperature of the wind with , higher than used previosuly in Réville et al. (2015a). This choice of higher sound speed drives the wind to slightly higher terminal speeds, which are more consistent with observed solar wind speeds. Each geometry is studied with 10 different field strengths controlled by the input parameter , which is defined here with the Alfvén speed on the stellar north pole (see following Section). Table 1 lists all our variations of for each geometry.
Due to the use of characteristic speeds as simulation inputs, our results can be scaled to any stellar parameters. For example, using solar parameters, the wind is driven by a coronal temperature of 1.4MK and our parameter space covers a range of stellar magnetic field strengths from 0.9G to 87G over the pole. Changing these normalisations will modify this range.
### 2.2. Magnetic Field Configuration
Within this work, we consider magnetic field geometries that encompass a range of dipole and quadrupole combinations with different relative strengths. We represent the mixed fields using the ratio, , of dipolar field to the total combined field strength.
In this study the magnetic fields of the dipole and quadrupole are described in the formalism of Gregory et al. (2010) using polar field strengths,
Br,dip(r,θ) = Bl=1∗(R∗r)3cosθ, (7) Bθ,dip(r,θ) = 12Bl=1∗(R∗r)3sinθ, (8) Br,quad(r,θ) = 12Bl=2∗(R∗r)4(3cos2θ−1), (9) Bθ,quad(r,θ) = Bl=2∗(R∗r)4cosθsinθ. (10)
The total field, comprised of the sum of the two geometries,
where the total polar field , is controlled by the parameter,
This work considers aligned magnetic moments such that ranges from 1 to 0, corresponding to all the field strength in the dipolar or quadrupolar mode respectively. As with , is calculated at the north pole. This sets the relative strengths of the dipole and quadrupole fields,
Bl=1∗=RdipB∗,Bl=2∗=(1−Rdip)B∗, (13)
Alternative parametrisations are commonly used in the analysis of ZDI observations and dynamo modelling. These communities use the surface averaged field strengths, , or the ratio of magnetic energy density () stored within each of the dipole and quadrupole field modes at the stellar surface. During the solar magnetic cycle, values of can range from at solar maximum to at solar minimum (DeRosa et al., 2012). A transformation from our parameter to the ratio of energies is simply given by:
where the numerical pre-factor accounts for the integration of magnetic energy in each mode over the stellar surface.
Initial field configurations are displayed in Figure 1. The pure dipolar and quadrupolar cases are shown in comparison to two mixed cases (). These combined geometry fields add in one hemisphere and subtract in the other. This effect is due to the different symmetry families each geometry belongs to, with the dipole’s polarity reversing over the equator unlike the equatorially symmetric quadrupole. Continuing the use of “primary” and “secondary” families as in McFadden et al. (1991) and DeRosa et al. (2012), we refer to the dipole as primary and quadrupole as secondary. The fields are chosen such that they align in polarity in the northern hemisphere. This choice has no impact on the derived torque or mass loss rate due to the symmetry of the quadrupole about the equator. Either aligned or anti-aligned, these fields will always create one additive hemisphere and one subtracting; swapping their relative orientations simply switches the respective hemispheres. This is in contrast to combining dipole & octupole fields, where the aligned and anti-aligned cases cause subtraction at the equator or poles respectively (Gregory et al., 2016; Finley & Matt. in prep).
Figure 1 indicates that even with equal quadrupole and dipole polar field strengths, , the overall dipole topology will remain. In this case the magnetic energy density in the dipolar mode is 1.5 times greater than the quadrupolar mode and with the more rapid radial decay of the quadrupolar field, this explains the overall dipolar topology. A higher fraction of quadrupole is required to produce a noticeable deviation from this configuration, which is shown at . More than half of the parameter space that we explore lies in the range where the energy density of the quadrupole mode is greater than that of the dipole (). For this study both the pure dipolar and quadrupolar fields are used as controls (both of which were studied in detail within Réville et al. (2015a)), and 5 mixed cases parametrised by values ( = 0.8, 0.5, 0.3, 0.2, 0.1). We include to demonstrate the dominance of the dipole at higher values. Each value is given a unique identifying colour which is maintained in all figures throughout this paper. Table 1 contains a complete list of parameters for all cases, which are numbered by increasing and quadrupole fraction.
## 3. Simulation results
### 3.1. Morphology of the Field and Wind Outflow
Figure 1 shows the topological changes in field structure from the addition of dipole and quadrupole fields. It is evident in these initial magnetic field configurations that the global magnetic field becomes asymmetric about the equator for mixed cases, as does the magnetic boundary condition which is maintained fixed at the stellar surface. It is not immediately clear how this will impact the torque scaling from Réville et al. (2015a), who studied only single geometries.
Results for these field configurations using our PLUTO simulations are displayed in Figure 2. The dipole and quadrupole cases are shown in conjunction with the mixed field cases, . The Figure displays for a comparable value of polar magnetic field strength, the different sizes of Alfvén surface that are produced. The mixed magnetic geometries modify the size and morphology of the Alfvén and sonic surfaces. Due to the slow rotation, the fast and slow magnetosonic surfaces are co-located with the sonic and Alfvén surfaces (the fast magnetosonic surface being always the larger of the two surfaces).
The field geometry is found to imprint itself onto the stellar wind velocity with regions of closed magnetic field confining the flow creating areas of co-rotating plasma, referred to as deadzones (Mestel, 1968). Steady state wind solutions typically have regions of open field where a faster wind and most of the torque is contained, along with these deadzone(s) around which a slower wind is produced. Similarly to the solar wind, slower wind can be found on the open field lines near the boundary of closed field (Feldman et al., 2005; Riley et al., 2006; Fisk et al., 1998). Observations of the Sun reveal the fast wind component emerging from deep within coronal holes, typically over the poles, and the slow wind component originating from the boundary between coronal holes and close field regions. Due to the polytropic wind used here, we do not capture the different heating and acceleration mechanisms required to create a true fast and slow solar-like wind (as seen with the Ulysses spacecraft e.g. McComas et al., 2000; Ebert et al., 2009). Our models produce an overall wind speed consistent with slow solar wind component, which we assume to represent the average global flow. More complex wind driving and coronal heating physics are required to recover a multi-speed wind, as observed from the Sun (Cranmer et al., 2007; Pinto et al., 2016).
Figure 3 displays a grid of simulations with a range of magnetic field strengths and values ( ranges from 3.6 to 54; values consistent with the solar cycle maximum), where the mixing of the fields plays a clear role in the changing dynamics of the flow. Regions of closed magnetic field cause significant changes to the morphology of the wind. A single deadzone is established on the equator by the dipole geometry whereas the quadrupole creates two over mid latitudes. Mixed cases have intermediate states between the pure regimes. Within our simulations the deadzones are accompanied by streamers which form above closed field regions and drive slower speed wind than from the open field regions. The dynamics of these streamers, their location and size are an interesting result of the changing topology of the flow.
The dashed coloured lines within Figure 3 show where the field polarity reverses using , which traces the location of the streamers. The motion of the streamers through the grid of simulations is then observed. With increasing quadrupole field, the single dipolar streamer moves into the northern hemisphere and with continued quadrupole addition a second streamer appears from the southern pole and travels towards the northern hemisphere until the quadrupolar streamers are recovered both sitting at mid latitudes. This motion can also be seen for fixed cases as the magnetic field strength is decreased. For a given value the current sheets sweep towards the southern hemisphere with increased polar field strength, in some cases (36 and 38) moving onto the axis of rotation. This is the opposite behaviour to decreasing the value, i.e. the streamer configuration is seen to take a more dipolar morphology as the field strength is increased. Additionally within Figure 3, for low field strengths each produces a comparable Alfvén surface with very similar morphology, all dominated by the quadrupolar mode.
### 3.2. Global Flow Quantities
Our simulations produce steady state solutions for the density, velocity and magnetic field structure. To compute the wind torque on the star we calculate , a quantity related directly to the angular momentum flux (Keppens & Goedbloed, 2000),
Λ(r,θ)=rsinθ(vϕ−Bϕρ|Bp|2vp⋅Bp). (15)
Within axisymmetric steady state ideal MHD, is conserved along any given field line. However we find variations from this along the open-closed field boundary due to numerical diffusion across the sharp transition in quantities found there. The spin-down torque, , due to the transfer of angular momentum in the wind is then given by the area integral,
τ=∫AΛρv⋅dA, (16)
where is the area of any surface enclosing the star. For illustrative purposes, Figure 3 shows the Alfvén surface coloured by angular momentum flux (thick multi-coloured line), which is seen to be strongly focused around the equatorial region. The angular momentum flux is calculated normal to the Alfvén surface,
dτdA=Λρv⋅^A=FAM⋅^A, (17)
where is the normal unit vector to the Alfvén surface. The mass loss rate from our wind solutions is calculated similarly to the torque,
˙M=∫Aρv⋅dA. (18)
Both expressions for the mass loss and torque are evaluated using spherical shells of area which are outside the closed field regions. This allows for the calculation of an average Alfvén radius (which is cylindrical from the rotation axis) in terms of the torque, mass flux and rotation rate,
⟨RA⟩=√τ˙MΩ∗. (19)
Throughout this work, is used as a normalised torque which accounts for the mass loss rates which we do not control. Values of the average Alfvén radius are tabulated within Table 1. is shown in Figure 3 using a grey vertical dashed line. For each case, the cylindrical Alfvén radius is offset inwards of the maximum Alfvén radius from the simulation, a geometrical effect as this corresponds to the average cylindrical and includes variations in flow quantities as well. Exploring Figure 3, the motion of the deadzones/current sheets have little impact on the overall torque. For example, no abrupt increase in the Alfvén radius is seen from case 34 to 36 (where the southern streamer is forced onto the rotation axis) compared to cases 44 and 46. The torque is instead governed by the magnetic field strength in the wind which controls the location of the Alfvén surface.
We parametrise the magnetic and mass loss properties using the “wind magnetisation” defined by,
Υ=B2∗R2∗˙Mvesc, (20)
where is the combined field strength at the pole. Previous studies that used this parameter defined it with the equatorial field strength (e.g. Matt & Pudritz, 2008; Matt et al., 2012; Réville et al., 2015a; Pantolmos & Matt. in prep). We use polar values unlike previous authors due to the additive property of the radial field at the pole, for aligned axisymmetric fields. Note that selecting one value of the field on the surface will not always produce a value which describes the field as a whole. The polar strength works for these aligned fields, but will easily break down for un-aligned fields and anti-aligned axisymmetric odd fields, thus it suits the present study, but a move away from this parameter in future is warranted.
During analysis, the wind magnetisation, , is treated as an independent parameter that determines the Alfvén radius and thus the torque, . We increase by setting a larger , creating a stronger global magnetic field. Table 1 displays all the input values of and as well as the resulting global outflow properties from our steady state solutions, which are used to formulate the torque scaling relations within this study. Figure 4 displays all 70 simulations in space. Cases are colour-coded here by their value, a convention which is continued throughout this work.
### 3.3. Single Mode Torque Scalings
The efficiency of the magnetic braking mechanism is known to be dependent on the magnetic field geometry. This has been previsously shown for single mode geometries (e.g. Réville et al., 2015a; Garraffo et al., 2016a). We first concider two pure gemetries, dipole and quadrupole, using the formulation from Matt & Pudritz (2008),
⟨RA⟩R∗=KsΥms, (21)
where and are fitting parameters for the pure dipole and quadrupole cases, using the surface field strength. Here we empirically fit ; the interpretation of is discussed in Matt & Pudritz (2008), Réville et al. (2015a) and Pantolmos & Matt (in prep), where it is determined to be dependant on magnetic geometry and the wind acceleration profile. The Appendix contains further discussion of the wind acceleration profile and its impact on this power law relationship.
The left panel of Figure 5 shows the Alfvén radii vs the wind magnetisations for all cases (colour-coded with their value). Solid lines show scaling relations for dipolar (red) and quadrupolar (blue) geometries, as first shown in Réville et al. (2015a). We calculate best fit values for and for the dipole and quadrupole, tabulated in Table 2. Values here differ due to our hotter wind ( than their ), using polar , and we do not account for our low rotation rate. As previously shown, the dipole field is far more efficient at transferring angular momentum than the quadrupole. In this study we concider the effect of combined geometries, within Figure 5 these cases lie between the dipole and quadrupole slopes, with no single power law of this form to describe them.
Pantolmos & Matt (in prep) have shown the role of the velocity profile in the power law dependence of the torque. In our simulations, the acceleration of the flow from the base wind velocity to its terminal speed is primarily governed by the thermal pressure gradient, however magnetic topologies can all modify the radial velocity profile (as can changes in wind temperature, , and rapid rotation, not included in our study). Effects on the torque formulations due to these differences in acceleration can be removed via the multiplication of with . In their work, the authors determine the theoretical power law dependence, , from one-dimensional analysis. In this formulation the slope of the power law is controlled only by the order of the magnetic geometry, , which is and for the dipole and quadrupole respectively,
⟨RA⟩R∗=Kl[Υvesc⟨v(RA)⟩]ml, (22)
where and are fit parameters to our wind solutions, tabulated in Table 2. The value of is calculated as an average of the velocity at all points on the Alfvén surface in the meridional plane. 3
Equation (22) is able to predict accurately the power law dependence for the two pure modes using the order of the spherical harmonic field, . We show this in the right panel of Figure 5, where the Alfvén radii are plotted against the new parameter, . A similar qualitative behaviour is shown to the scaling with in the left panel. Using the theoretical power law dependencies, the dipolar (red) and quadrupolar (blue) slopes are plotted with and respectively. Using a single fit constant for both sloes within this figure shows good agreement with the simulation results.
More accurate values of and are fit for each mode independently. These values produce a better fit and are compared with the theoretical values in Table 2. The mixed simulations show a similar qualitative behaviour to the plot against .
Obvious trends are seen within the mixed case scatter. A saturation to quadrupolar Alfvén radii values for lower and values is observed, along with a power law trend with a dipolar gradient for higher and values. This indicates that both geometries play a role in governing the lever arm, with the dipole dominating the braking process at higher wind magnetisations.
### 3.4. Broken Power Law Scaling For Mixed Field Cases
Observationally the field geometries of cool stars are, at large scales, dominated by the dipole mode with higher order modes playing smaller roles in shaping the global field. It is the global field which controls the spin-down torque in the magnetic braking process. Higher order modes (such as the quadrupole) decay radially much faster than the dipole and as such they have a reduced contribution to setting the Alfvén speed at distances larger than a few stellar radii.
We calculate , which only takes into account the dipole’s field strength,
Υdip=(Bl=1∗B∗)2B2∗R2∗˙Mvesc=R2dipΥ. (23)
Taking as a hypothesis that the field controlling the location of the Alfvén radius is the dipole component, a power law scaling using can be constructed in the same form as Matt & Pudritz (2008),
⟨RA⟩R∗=Ks,dip[Υdip]ms,dip=Ks,dip[R2dipΥ]ms,dip. (24)
Substitution of the dipole component into equation (22) similarly gives,
⟨RA⟩R∗=Kl,dip[R2dipΥvesc⟨v(RA)⟩]ml,dip, (25)
where , , , and will be parameters fit to simulations.
A comparison of these approximations can be seen in Figure 5, where equations (24) (left panel) and (25) (right panel) are plotted with dashed lines for all the values used in our simulations. Mixed cases which lie above the quadrupolar slope are shown to agree with the dashed-lines in both forms. Such cases are dominated by the dipole component of the field only, irrespective of the quadrupolar component.
The role of the dipole is even more clear in Figure 6 where only the dipole component of is plotted for each simulation. The solid red line in Figure 6, given by equation (24), shows agreement at a given with deviation from this caused by a regime change onto the quadrupolar slope (shown in dashed colour).
The behaviour of our simulated winds, despite using a combination of field geometries, simply follow existing scaling relations with this modification. In general, the dipole () prediction shows good agreement with the simulated wind models, except in cases where the Alfvén surface is close-in to the star. In these cases, the quadrupole mode still has magnetic field strength able to control the location of the Alfvén surface. Interestingly, and in contrast to the dipole-dominated regime, the quadrupole dominated regime behaves as if all the field strength is within the quadrupolar mode. This is visible within Figure 5 for low values of and .
The mixed field scaling can be described as a broken power law, set by the maximum of either the dipole component or the pure quadrupolar relation. With the break in the power law given by ,
where is the location of the intercept for the dipole component and pure quadrupole scalings,
The solid lines in Figure 4 show the value of , equation (27), diving the two regimes. Specifically, the solutions above the solid black line behave as if only the dipole component () is governing the Alfvén radius.
Transitioning from regimes is not perfectly abrupt. Therefore producing an analytical solution for the mixed cases which includes this behaviour would increase the accuracy for stars near the regime change. E.g. we have formulated a slightly better fit, using a relationship based on the quadrature addition of different regions of field. However it provides no reduction to the error on this simpler form and is not easily generalised to higher topologies. For practical purposes, the scaling of equation (26) and (27) predict accurately the simulation torque with increasing magnetic field strength for a variety of dipole fractions. We therefore present the simplest available solution, leaving the generalised form to be developed within future work.
## 4. The impact of geometry on the magnetic flux in the wind
### 4.1. Evolution of the Flux
The magnetic flux in the wind is a useful diagnostic tool. The rate of the stellar flux decay with distance is controlled by the overall magnetic geometry. We calculate the magnetic flux as a function of radial distance by evaluating the integral of the magnetic field threading closed spherical shells, where we take the absolute value of the flux to avoid field polarity cancellations,
Φ(r)=∮r|B⋅dA|. (28)
Considering the initial potential fields of the two pure modes this is simply a power law in field order ,
Φ(r)P=Φ∗(R∗r)l, (29)
where dipole and quadrupole, we denote the flux with “” for the potential field. Figure 7 displays the flux decay of all values of for each value, grey lines. The behaviour is qualitatively identical to that observed within previous works (e.g. Schrijver et al., 2003; Johnstone et al., 2010; Vidotto et al., 2014a; Réville et al., 2015a), where the field decays as the potential field does until the pressure of the wind forces the field into a purely radial configuration with a constant magnetic flux, referred to as the open flux. The power law dependence of equation (29) indicates for higher mode magnetic fields, the decay will be faster. We therefore expect the more quadrupolar dominated fields studied in this work to have less open flux.
In the case of mixed geometries a simple power law is not available for the initial potential configurations, instead we evaluate the flux using equation (28), where is the initial potential field for each mixed geometry. This allows us to calculate the radial evolution of the flux for a given which we compare to the simulated cases. Figure 7 shows the flux normalised by the surface flux versus radial distance from the star. For each value, the magnetic flux decay of the potential field (black solid line) is shown with the different strength simulations (grey solid lines). A comparison of the flux decay for all potential magnetic geometries is available in the bottom right panel showing, as expected, the increasingly quadrupolar fields decaying faster.
In this study we control which, for a given surface density, sets the polar magnetic field strength for our simulations. The stellar flux for different topologies and the same will differ and must be taken into account in order to describe the dipole and quadrupolar components (dashed red and blue) in Figure 7. We plot the magnetic flux of the potential field quadrupole component alone in dotted blue for each value,
and similarly the potential field dipole component of the magnetic flux,
Φ(r)P,dip=RdipΦ∗,dip(R∗r), (31)
where in both equations the surface flux of a pure dipole/quadrupole (, ) field is required to match our normalised flux representation.
Due to the rapid decay of the quadrupolar mode, the flux at large radial distances for all simulations containing the dipole mode is described by the dipolar component. The quadrupole component decay sits below and parallel to the potential field prediction for small radii, becoming indistinguishable for the lowest values as the flux stored in the dipole is decreased. Importantly for small radii, simulations containing a quadrupolar component are dominated by the quadrupolar decay following a power law decay, which can be seen by shifting the blue dashed line upwards to intercept at the stellar surface.
This result for the flux decay is reminiscent of the broken power law description for the Alfvén radius in Section 3.4. The field acts as a quadrupole using the total field for small radii and the dipole component only for large radii. There is a transition between these two regimes that is not described by either approximation. But is shown by the potential solution in solid black.
### 4.2. Topology Independent Open Flux Formulation
The magnetic flux within the wind decays following the potential field solution closely until the magnetic field geometry is opened by the pressures of the stellar wind and the field lines are forced into a nearly radial configuration with constant flux, shown in Figure 7 for all simulations. The importance of this open flux is discussed by Réville et al. (2015a). These authors showed a single power law dependence for the Alfvén radius, independent of magnetic geometry, when parametrised in terms of the open flux, ,
Υopen=Φ2open/R2∗˙Mvesc, (32)
which, ignoring the effects of rapid rotation, can be fit with,
⟨RA⟩R∗=Ko[Υopen]mo, (33)
where, and are fitting parameters for the open flux formulation.
Using the open flux parameter, Figure 8 shows a collapse towards a single power law dependence as in Réville et al. (2015a). However our wind solutions show a systematic difference in power law dependence from dipole to quadrupole. On careful inspection of the result from Figure 6 of Réville et al. (2015a), the same systematic trend between their topologies and the fit scaling is seen. 4 We calculate best fits for each pure mode separately i.e. the dipole and quadrupole, tabulated in Table 3.
Pantolmos & Matt (in prep) find solutions for thermally driven winds with different coronal temperatures, from these they find the wind acceleration profiles of a given wind to very significantly alter the slope in - space. From this work our trend with geometry indicates that each geometry must have a slightly different wind acceleration profile. This is most likely due to difference in the super radial expansion of the flux tubes for each geometry, which is not taken into account with equation (33). The field geometry is imprinted onto the wind as it accelerates out to the Alfvén surface. As such, this scaling relation is not entirely independent of topology. Further details on the wind acceleration profile within our study is available in the Appendix. Pantolmos (in prep) are able to include the effects of acceleration in their scaling through multiplication of with . The expected semi-analytic solution from Pantolmos & Matt (in prep) is given,
⟨RA⟩R∗=Kc[Υopenvesc⟨v(RA)⟩]mc, (34)
where the fit parameters are derived from one-dimensional theory as constants, and .
We are able to reproduce this power law fit of with the wind acceleration effects removed, on the right panel of Figure 8. Including all simulations in the fit, we arrive at values of and for the constants of proportionality and power law dependence. However a systematic difference is still seem from one value to another. More precise fits can be found for each geometry independently, but the systematic difference appearing in the right panel implies a modification to our semi-analytic formulations is required to describe the torque fully in terms of the open flux.
Here we show the scaling law from Réville et al. (2015a) is improved with the modification from Pantlomos (in prep). This formulation is able to describe the Alfvén radius scaling with changing open flux and mass loss. However with the open flux remaining an unknown from observations and difficult to predict, scaling laws that incorporate known parameters (such as those of equations (26) and (27)) are still needed for rotational evolution calculations.
### 4.3. The Relationship Between the Opening and Alfvén Radii
The location of the field opening is an important distance. It is both critical for determining the torque and for comparison to potential field source surface (PFSS) models (Altschuler & Newkirk, 1969), which set the open flux with a tunable free parameter . The opening radius, , we define is the radial distance at which the potential flux reaches the value of the open flux (). This definition is chosen because it relates to the 1D analysis employed to describe the power law dependences of our torque scaling relations. Specifically, a known value of allows for a precise calculation of the open flux (a priori from the potential field equations), which then gives the torque on the star within our simulations. The physical opening of the simulation field takes place at slightly larger radii than this with the field becoming non-potential due to its interaction with the wind (which explains why the closed field regions seen in Figure 3 typically extend slightly beyond ). A similar smooth transition is produced with PFSS modelling.â
is marked for each simulation in Figure 7 and again for comparative purposes in the bottom right panel. It is clear that smaller opening radii are found for lower cases. Due to their more rapidly decaying flux, they tend to have a smaller fraction of the stellar flux remaining in the open flux. From the radial decay of the magnetic field, the open flux and opening radii are observed to be dependent on the available stellar flux and topology. Pantolmos & Matt (in prep) have recently shown these to also be dependent on the wind acceleration profile. This complex dependence makes it difficult to predict the open flux for a given system.
A method for predicting within our simulations remains unknown, however it is understood that is key to predicting the torque from our simulated winds. We do however find the ratio of to be roughly constant for a given geometry, deviations from which may be numerical or suggest additional physics which we do not explore here.
## 5. Conclusion
We undertake a systematic study of the two simplest magnetic geometries, dipolar and quadrupolar, and for the first time their combinations with varying relative strengths. We parametrise the study using the ratio, , of dipolar to total combined field strength, which is shown to be a key variable in our new torque formulation.
We have shown that a large proportion of the magnetic field energy needs to be in the quadrupole for any significant morphology changes to be seen in the wind. All cases above 50% dipole field show a single streamer and are dominated by dipolar behaviour. Even in cases of small we observe the dipole field to be the key parameter controlling the morphology of the flow, with the quadrupolar field rapidly decaying away for most cases leaving the dipole component behind. For smaller field strengths the Alfvén radii appears close to the star, where the quadrupolar field is still dominant, and thus a quadrupolar morphology is established. Increasing the fraction of quadrupolar field strength allows this behaviour to continue for larger Alfvén radii.
The morphology of the wind can be concidered in the context of star-planet or disk interactions. Our findings suggest that the connectivity, polarity and strength of the field within the orbital plane depend in a simple way on the relative combination of dipole and quadrupole fields. Different combinations of these two field modes change the location of the current sheet(s) and the relative orientation of the stellar wind magnetic field with respect to any planetary or disk magnetic field. Asymmetries such as these can modify the poynting flux exchange for close-in planets (Strugarek et al., 2014b) or the strength of magnetospheric driving and geomagnetic storms on Earth-like exoplanets. Cohen et al. (2014) use observed magnetic fields to simulate the stellar wind environment surrounding the planet hosting star EV Lac. They calculate the magnetospheric joule heating on the exoplanets orbiting the M dwarf, finding significant changes to atmospheric properties such as thickness and temperature. Additionally, transient phenomena in the Solar wind such as coronal mass ejections are shown to deflect towards streamer belts (Kay et al., 2013). This has been applied to mass ejections around M dwarfs stars (Kay & Opher, 2014), and could similarly be applied here using knowledge of the streamer locations from our model grid.
If the host star magnetic field can be observed and decomposed into constituent field modes, containing dominant dipole and quadrupole components, a qualitative assessment of the stellar wind environment can be made. We find the addition of these primary and secondary fields to create an asymmetry which may shift potentially habitable exoplanets in and out of volatile wind streams. Observed planet hosting stars such as Bootis have already been shown to have global magnetic fields which are dominated by combinations of these low order field geometries (Donati et al., 2008). With further investigation it is possible to qualitatively approximate the conditions for planets in orbit of such stars. For dipole and quadrupole dominated host stars with a given magnetic field strength our grid of models provide an estimate of the location of the streamers and open field regions.
Within this work we build on the scaling relations from, Matt et al. (2012), Réville et al. (2015a) and Pantolmos & Matt (in prep). We confirm existing scaling laws and explore a new mixed field parameter space with similar methods. From our wind solutions we fit the variables, , , and (see Table 4), which describe the torque scaling for the pure dipole and quadrupole modes. From the 50 mixed case simulations, we produce an approximate scaling relation which takes the form of a broken power law, as a single power law fit is not available for the mixed geometries cases in space.
For low and low dipole fraction, the Alfvén radius behaves like a pure quadrupole,
At higher and dipole fractions, the torque is only dependent on the dipolar component of the field,
τ=Ks,dip˙MΩ∗R2∗[Υdip]2ms,dip, (37)
=Ks,dip˙M1−2ms,dipΩ∗R2+4ms,dip∗[(Bl=1∗)2vesc]2ms,dip. (38)
The later formulation is used when the Alfvén radius of a given dipole & quadrupole mixed field is greater than the pure quadrupole case for the same , i.e. the maximum of our new formula or the pure quadrupole. We define to separate the two regimes (see Figure 4).
The importance of the relative radial decay of both modes and the location of the opening and Alfvén radii appear to play a key role, and deserve further follow up investigation. This work analytically fits the decay of the magnetic flux, but a parametric relationship for the field opening remains uncertain. The relation of the relative sizes of the Alfvén and opening radii are found to be dependent on geometry, which can be used to inform potential field source surface modelling, where by the source surface must be specified when changing the field geometry.
Paper II includes the addition of octupolar field geometries, another primary symmetry family which introduces an additional complication in the relative orientation of the octupole to the dipole. It is shown however, that the mixing of any two axisymmetric geometries will follow a similar behaviour, especially if each belongs to different symmetry families (Finley & Matt. in prep). The lowest order mode largely dominates the dynamics of the torque until the Alfvén radii and opening radii are sufficiently close to the star for the higher order modes to impact the field strength.
Thanks for helpful discussions and technical advice from Georgios Pantolmos & Matt, Victor See, Victor Réville, Sasha Brun and Claudio Zanni. This project has received funding from the European Research Council (ERC) under the European Unionâs Horizon 2020 research and innovation programme (grant agreement No 682393). We thank Andrea Mignone and others for the development and maintenance of the PLUTO code. Figures within this work are produced using the python package matplotlib (Hunter, 2007).
## Appendix A Wind Acceleration
The creation of a semi-analytic formulation for the Alfvén radius for a variety of stellar parameters has been the goal of many studies proceeding this (e.g. Matt & Pudritz, 2008; Matt et al., 2012; Réville et al., 2015a; Pantolmos & Matt. in prep). Using a one-dimensional approximation based on work by Kawaler (1988), previous studies have aimed to predict the power law dependence, , of the torque formulations used within this work.
Using the one-dimensional framework, the field strength is assumed to decay as a power law , which in this study is only valid for the pure cases. Pantolmos & Matt (in prep) show the effect of wind acceleration can be removed from the torque scaling relations through the multiplication of and with . The power law dependences then becomes,
ml,th=1/(2l+2), (A1)
and similarly,
mc,th=1/2. (A2)
The modified dependent parameter, , is used throughout this work (see Figures 5 and 8), and the analytic predictions for the power law slopes are shown to have good agreement with our simulations. This dependent variable however, requires additional information about the wind speed at the Alfvén surface which is often unavailable.
Typically, rotation evolution models use the available stellar surface parameters e.g. . Therfore knowledge of the flow speed at the Alfvén radius, , is required for the semi-analytic formulations. is shown by Pantolmos & Matt. (in prep) and Réville et al. (2015a) to share a similar profile to a one-dimensional thermal wind, . Figure 10 displays the average Alfvén speed vs the Alfvén radius for all 70 simulations (coloured points). The parker wind solution (Parker, 1965) used in the initial condition is displayed for comparison (dashed line). Nearly all simulations follow the hydrodynamic solution, with a behaviour mostly independent of . Towards higher values of the Alfvén radius, a noticeable separation starts to develop between geometries. This range is accessed less by the higher order geometries as the range of Alfvén radii is much smaller than that for the pure dipole mode.
In order to include the effects of wind acceleration in the simplified 1D analysis to explain the simulation scalings between and , Réville et al. (2015a) introduced a parametrisation for the acceleration of the wind to the Alfvén radius with a power law dependence in radial distance using ,
v(RA)/vesc=(RA/R∗)q. (A3)
A single power law with is fit to the simulation data, which is chosen for simplicity within the 1D formalism. The use of this parameter is approximate if is a power law in , which we show over the parameter space has a significant deviation. Using the semi-analytic theory, Réville et al. (2015a) then derived the power law dependence for the scaling (Equation (21)),
ms,th=1/(2l+2+q), (A4)
which includes geometric and wind acceleration parameters in the form of and respectively. Using this result, is computed for both the dipole () and quadrupole () geometries in Table 4, and compared to the simulation results with good agreement.
Pantolmos & Matt. (in prep) explain the power-law dependence, so long as remains constant and the wind acceleration profile is known. Reiners & Mohanty (2012), Réville et al. (2015a) and Pantolmos & Matt. (in prep) all analytically describe the power law dependence of the open flux formulation (Equation (33)) using the power law dependence ,
mo,th=1/(2+q). (A5)
The result is independent of geometry, . As before the parameter approximates the wind driving as a power law in radius, which is fit with a single power law for both geometries such that should be the same for both the dipole and quadrupole. This prediction is tabulated in Table 4, however the simulation slopes are shown to no longer agree with the result. It is suggested that the open flux slope is much more sensitive to the wind acceleration than the formulation, therefore slight changes in flow acceleration modify the result. Slightly different slopes can be fit for the dipole and quadrupole cases which can recover the different values, however this is seemingly just a symptom of the power law approximation breaking down.
We conclude that the approximate power law of equation (A3) give a reasonable adjustment to the torque prediction for known wind velocity profiles, despite the badness of fit to the simulations points. Even though the power-law approximation to the wind velocity profile (equation A3) is not a precise fit to the data in Figure 10, the value of does provide a way to approximately include the contribution of the wind acceleration to the fit power-law exponents and . A more precise formulation could be derived based on a Parker-like wind profile without the use of a power law, however the torque scaling with is relative insensitive to the chosen approximate velocity profile.
### Footnotes
1. slugcomment: Draft: March 6, 2018
2. The PLUTO code operates with a factor of absorbed into the normalisation of B. Tabulated parameters are given in cgs units with this factor incorporated.
3. It could be argued that this should be weighted by the total area of the Alfvén surface, but for simplicity we calculate the un-weighted average.
4. A choice in our parameter space may have made this clearer to see in Figure 8, due to the increased heating and therefore larger range of acceleration allowing the topology to impact the velocity profile.
### References
1. Agüeros, M. A., Covey, K. R., Lemonias, J. J., et al. 2011, The Astrophysical Journal, 740, 110
2. Altschuler, M. D., & Newkirk, G. 1969, Solar Physics, 9, 131
3. Alvarado-Gómez, J., Hussain, G., Cohen, O., et al. 2016, Astronomy & Astrophysics, 594, A95
4. Amard, L., Palacios, A., Charbonnel, C., Gallet, F., & Bouvier, J. 2016, Astronomy & Astrophysics, 587, A105
5. Barnes, S. A. 2003, The Astrophysical Journal, 586, 464
6. —. 2010, The Astrophysical Journal, 722, 222
7. Blackman, E. G., & Owen, J. E. 2016, Monthly Notices of the Royal Astronomical Society, 458, 1548
8. Bouvier, J., Matt, S. P., Mohanty, S., et al. 2014, Protostars and Planets VI, 433
9. Brown, T. M. 2014, The Astrophysical Journal, 789, 101
10. Cohen, O., Drake, J., Glocer, A., et al. 2014, The Astrophysical Journal, 790, 57
11. Cohen, O., Drake, J., Kashyap, V., Hussain, G., & Gombosi, T. 2010, The Astrophysical Journal, 721, 80
12. Cohen, O., & Drake, J. J. 2014, The Astrophysical Journal, 783, 55
13. Cohen, O., Kashyap, V., Drake, J., et al. 2011, The Astrophysical Journal, 733, 67
14. Cranmer, S. R., & Saar, S. H. 2011, The Astrophysical Journal, 741, 54
15. Cranmer, S. R., Van Ballegooijen, A. A., & Edgar, R. J. 2007, The Astrophysical Journal Supplement Series, 171, 520
16. Davenport, J. R. A. 2017, ApJ, 835, 16
17. DeRosa, M., Brun, A., & Hoeksema, J. 2012, The Astrophysical Journal, 757, 96
18. do Nascimento Jr, J.-D., Vidotto, A., Petit, P., et al. 2016, The Astrophysical Journal Letters, 820, L15
19. Donati, J.-F., Moutou, C., Fares, R., et al. 2008, Monthly Notices of the Royal Astronomical Society, 385, 1179
20. Dunstone, N., Hussain, G., Collier Cameron, A., et al. 2008, Monthly Notices of the Royal Astronomical Society, 387, 481
21. Ebert, R., McComas, D., Elliott, H., Forsyth, R., & Gosling, J. 2009, Journal of Geophysical Research: Space Physics, 114
22. Einfeldt, B. 1988, SIAM Journal on Numerical Analysis, 25, 294
23. Fares, R., Donati, J.-F., Moutou, C., et al. 2009, Monthly Notices of the Royal Astronomical Society, 398, 1383
24. —. 2010, Monthly Notices of the Royal Astronomical Society, 406, 409
25. Feldman, U., Landi, E., & Schwadron, N. 2005, Journal of Geophysical Research: Space Physics, 110
26. Fisk, L., Schwadron, N., & Zurbuchen, T. 1998, Space Science Reviews, 86, 51
27. Folsom, C. P., Petit, P., Bouvier, J., et al. 2016, Monthly Notices of the Royal Astronomical Society, 457, 580
28. Gallet, F., & Bouvier, J. 2013, Astronomy & Astrophysics, 556, A36
29. —. 2015, Astronomy & Astrophysics, 577, A98
30. Garraffo, C., Drake, J. J., & Cohen, O. 2016a, Astronomy & Astrophysics, 595, A110
31. —. 2016b, The Astrophysical Journal Letters, 833, L4
32. Grappin, R., Leorat, J., & Pouquet, A. 1983, Astronomy and Astrophysics, 126, 51
33. Gregory, S., Jardine, M., Gray, C., & Donati, J. 2010, Reports on Progress in Physics, 73, 126901
34. Gregory, S. G., Donati, J.-F., & Hussain, G. A. 2016, arXiv preprint arXiv:1609.00273
35. Hall, J. C., Lockwood, G., & Skiff, B. A. 2007, The Astronomical Journal, 133, 862
36. Hébrard, É., Donati, J.-F., Delfosse, X., et al. 2016, Monthly Notices of the Royal Astronomical Society, 461, 1465
37. Hunter, J. D. 2007, Computing In Science & Engineering, 9, 90
38. Irwin, J., & Bouvier, J. 2009, in IAU Symp, Vol. 258
39. Jardine, M., Barnes, J. R., Donati, J.-F., & Cameron, A. C. 1999, Monthly Notices of the Royal Astronomical Society, 305, L35
40. Jardine, M., Collier Cameron, A., & Donati, J.-F. 2002, Monthly Notices of the Royal Astronomical Society, 333, 339
41. Jeffers, S., Petit, P., Marsden, S., et al. 2014, Astronomy & Astrophysics, 569, A79
42. Johnstone, C., Güdel, M., Lüftinger, T., Toth, G., & Brott, I. 2015, Astronomy & Astrophysics, 577, A27
43. Johnstone, C., Jardine, M., & Mackay, D. 2010, Monthly Notices of the Royal Astronomical Society, 404, 101
44. Kawaler, S. D. 1988, The Astrophysical Journal, 333, 236
45. Kay, C., & Opher, M. 2014, in American Astronomical Society Meeting Abstracts# 224, Vol. 224
46. Kay, C., Opher, M., & Evans, R. M. 2013, The Astrophysical Journal, 775, 5
47. Keppens, R., & Goedbloed, J. 1999, Astron. Astrophys, 343, 251
48. —. 2000, The Astrophysical Journal, 530, 1036
49. Matt, S., & Pudritz, R. E. 2008, The Astrophysical Journal, 678, 1109
50. Matt, S. P., Brun, A. S., Baraffe, I., Bouvier, J., & Chabrier, G. 2015, The Astrophysical Journal Letters, 799, L23
51. Matt, S. P., MacGregor, K. B., Pinsonneault, M. H., & Greene, T. P. 2012, The Astrophysical Journal Letters, 754, L26
52. McComas, D., Barraclough, B., Funsten, H., et al. 2000, Journal of Geophysical Research: Space Physics, 105, 10419
53. McFadden, P., Merrill, R., McElhinny, M., & Lee, S. 1991, Journal of Geophysical Research: Solid Earth, 96, 3923
54. McQuillan, A., Aigrain, S., & Mazeh, T. 2013, Monthly Notices of the Royal Astronomical Society, 432, 1203
55. Meibom, S., Mathieu, R. D., Stassun, K. G., Liebesny, P., & Saar, S. H. 2011, The Astrophysical Journal, 733, 115
56. Mestel, L. 1968, Monthly Notices of the Royal Astronomical Society, 138, 359
57. —. 1984, in Cool Stars, Stellar Systems, and the Sun (Springer), 49
58. Mignone, A. 2009, Memorie della Societa Astronomica Italiana Supplementi, 13, 67
59. Mignone, A., Bodo, G., Massaglia, S., et al. 2007, The Astrophysical Journal Supplement Series, 170, 228
60. Morgenthaler, A., Petit, P., Morin, J., et al. 2011, Astronomische Nachrichten, 332, 866
61. Morgenthaler, A., Petit, P., Saar, S., et al. 2012, Astronomy & Astrophysics, 540, A138
62. Morin, J., Donati, J.-F., Petit, P., et al. 2008, Monthly Notices of the Royal Astronomical Society, 390, 567
63. Nicholson, B., Vidotto, A., Mengel, M., et al. 2016, Monthly Notices of the Royal Astronomical Society, 459, 1907
64. Oran, R., Landi, E., van der Holst, B., et al. 2015, The Astrophysical Journal, 806, 55
65. Parker, E. 1965, Space Science Reviews, 4, 666
66. Parker, E. N. 1958, The Astrophysical Journal, 128, 664
67. Petit, P., Dintrans, B., Morgenthaler, A., et al. 2009, Astronomy & Astrophysics, 508, L9
68. Petit, P., Dintrans, B., Solanki, S., et al. 2008, Monthly Notices of the Royal Astronomical Society, 388, 80
69. Pinto, R., Brun, A., & Rouillard, A. 2016, Astronomy & Astrophysics, 592, A65
70. Pinto, R. F., Brun, A. S., Jouve, L., & Grappin, R. 2011, The Astrophysical Journal, 737, 72
71. Reiners, A., & Mohanty, S. 2012, The Astrophysical Journal, 746, 43
72. Réville, V., Brun, A. S., Matt, S. P., Strugarek, A., & Pinto, R. F. 2015a, The Astrophysical Journal, 798, 116
73. Réville, V., Brun, A. S., Strugarek, A., et al. 2015b, The Astrophysical Journal, 814, 99
74. Réville, V., Folsom, C. P., Strugarek, A., & Brun, A. S. 2016, The Astrophysical Journal, 832, 145
75. Riley, P., Linker, J., Mikić, Z., et al. 2006, The Astrophysical Journal, 653, 1510
76. Rosén, L., Kochukhov, O., & Wade, G. A. 2015, The Astrophysical Journal, 805, 169
77. Rosner, R., Golub, L., & Vaiana, G. 1985, Annual review of astronomy and astrophysics, 23, 413
78. Saikia, S. B., Jeffers, S., Morin, J., et al. 2016, Astronomy & Astrophysics, 594, A29
79. Sakurai, T. 1990, Computer Physics Reports, 12, 247
80. Schrijver, C. J., DeRosa, M. L., et al. 2003, The Astrophysical Journal, 590, 493
81. See, V., Jardine, M., Vidotto, A., et al. 2015, Monthly Notices of the Royal Astronomical Society, 453, 4301
82. —. 2016, Monthly Notices of the Royal Astronomical Society, 462, 4442
83. —. 2017, Monthly Notices of the Royal Astronomical Society, stw3094
84. Skumanich, A. 1972, The Astrophysical Journal, 171, 565
85. Soderblom, D. 1983, The Astrophysical Journal Supplement Series, 53, 1
86. Stauffer, J., Rebull, L., Bouvier, J., et al. 2016, The Astronomical Journal, 152, 115
87. Strugarek, A., Brun, A., Matt, S., et al. 2014a, in SF2A-2014: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics, 279
88. Strugarek, A., Brun, A. S., Matt, S. P., & Réville, V. 2014b, The Astrophysical Journal, 795, 86
89. Tóth, G. 2000, Journal of Computational Physics, 161, 605
90. Ud-Doula, A., Owocki, S. P., & Townsend, R. H. 2009, Monthly Notices of the Royal Astronomical Society, 392, 1022
91. Usmanov, A. V., Goldstein, M. L., & Matthaeus, W. H. 2014, The Astrophysical Journal, 788, 43
92. Ustyugova, G., Koldoba, A., Romanova, M., & Lovelace, R. 2006, The Astrophysical Journal, 646, 304
93. Van der Holst, B., Manchester IV, W., Frazin, R., et al. 2010, The Astrophysical Journal, 725, 1373
94. van der Holst, B., Sokolov, I. V., Meng, X., et al. 2014, The Astrophysical Journal, 782, 81
95. Van Saders, J. L., & Pinsonneault, M. H. 2013, The Astrophysical Journal, 776, 67
96. Vidotto, A., Jardine, M., Morin, J., et al. 2014a, Monthly Notices of the Royal Astronomical Society, 438, 1162
97. Vidotto, A., Jardine, M., Opher, M., Donati, J., & Gombosi, T. 2011, in 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Vol. 448, 1293
98. Vidotto, A., Gregory, S., Jardine, M., et al. 2014b, Monthly Notices of the Royal Astronomical Society, 441, 2361
99. Washimi, H., & Shibata, S. 1993, Monthly Notices of the Royal Astronomical Society, 262, 936
100. Weber, E. J., & Davis, L. 1967, The Astrophysical Journal, 148, 217
101. Wolk, S., Harnden Jr, F., Flaccomio, E., et al. 2005, The Astrophysical Journal Supplement Series, 160, 423
102. Wood, B. E. 2004, Living Reviews in Solar Physics, 1, 1
103. Wright, J. T., Marcy, G. W., Butler, R. P., & Vogt, S. S. 2004, The Astrophysical Journal Supplement Series, 152, 261
104. Zanni, C., & Ferreira, J. 2009, Astronomy & Astrophysics, 508, 1117
You are adding the first comment!
How to quickly get a good reply:
• Give credit where it’s due by listing out the positive aspects of a paper before getting into which changes should be made.
• Be specific in your critique, and provide supporting evidence with appropriate references to substantiate general statements.
• Your comment should inspire ideas to flow and help the author improves the paper.
The better we are at sharing our knowledge with each other, the faster we move forward.
The feedback must be of minimum 40 characters and the title a minimum of 5 characters | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9277281165122986, "perplexity": 1829.1633254729281}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560627999948.3/warc/CC-MAIN-20190625213113-20190625235113-00186.warc.gz"} |
https://socratic.org/questions/can-a-repeating-decimal-be-equal-to-an-integer#152124 | Precalculus
Topics
# Can a repeating decimal be equal to an integer?
Jun 11, 2015
No, it will allways turn out to be a fraction.
#### Explanation:
I will not delve into how you turn a repeating decimal into a fraction, but just one example:
$0.333 \ldots . = \frac{1}{3}$
There is one exeption though (see example above):
$0.999 \ldots . = 3 \cdot 0.333 \ldots . = 3 \cdot \frac{1}{3} = 1$
Dec 18, 2016
Yes
#### Explanation:
The general term of a geometric series can be written:
${a}_{n} = a \cdot {r}^{n - 1}$
where $a$ is the initial term and $r$ the common ratio.
When $\left\mid r \right\mid < 1$ then its sum to infinity converges and is given by the formula:
${\sum}_{n = 1}^{\infty} a {r}^{n - 1} = \frac{a}{1 - r}$
So for example:
$0.999 \ldots = \frac{9}{10} + \frac{9}{100} + \frac{9}{1000} + \ldots$
is given by $a = 9$ and $r = \frac{1}{10}$
which has sum:
${\sum}_{n = 1}^{\infty} \frac{9}{10} \cdot {\left(\frac{1}{10}\right)}^{n - 1} = \frac{\frac{9}{10}}{1 - \frac{1}{10}} = \frac{\frac{9}{10}}{\frac{9}{10}} = 1$
So $0. \overline{9} = 0.999 \ldots = 1$
In fact, any integer can be expressed as a repeating decimal using $9$'s.
For example:
$12345 = 12344.999 \ldots = 12344. \overline{9}$
$- 5 = - 4.999 \ldots = - 4. \overline{9}$
##### Impact of this question
4102 views around the world | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 15, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9448901414871216, "perplexity": 946.8270910323582}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652662545326.51/warc/CC-MAIN-20220522094818-20220522124818-00797.warc.gz"} |
https://au.mathworks.com/help/simbio/ref/sbionlinfit.html | # sbionlinfit
Perform nonlinear least-squares regression using SimBiology models (requires Statistics and Machine Learning Toolbox software)
`sbionlinfit` will be removed in a future release. Use `sbiofit` instead.
## Syntax
```results = sbionlinfit(modelObj, pkModelMapObject, pkDataObj, InitEstimates) results = sbionlinfit(modelObj, pkModelMapObject, pkDataObj, InitEstimates, Name,Value) results = sbionlinfit(modelObj, pkModelMapObject, pkDataObj, InitEstimates, optionStruct) [results, SimDataI] = sbionlinfit(...) ```
## Description
`results = sbionlinfit(modelObj, pkModelMapObject, pkDataObj, InitEstimates)` performs least-squares regression using the SimBiology® model, `modelObj`, and returns estimated results in the `results` structure.
`results = sbionlinfit(modelObj, pkModelMapObject, pkDataObj, InitEstimates, Name,Value)` performs least-squares regression, with additional options specified by one or more `Name,Value` pair arguments.
Following is an alternative to the previous syntax:
`results = sbionlinfit(modelObj, pkModelMapObject, pkDataObj, InitEstimates, optionStruct)` specifies `optionStruct`, a structure containing fields and values used by the `options` input structure to the `nlinfit` function.
```[results, SimDataI] = sbionlinfit(...)``` returns simulations of the SimBiology model, `modelObj`, using the estimated values of the parameters.
## Input Arguments
`modelObj`
SimBiology model object used to fit observed data.
### Note
If using a model object containing active doses (that is, containing dose objects created using the `adddose` method, and specified as active using the `Active` property of the dose object), be aware that these active doses are ignored by the `sbionlinfit` function.
`pkModelMapObject`
`PKModelMap` object that defines the roles of the model components in the estimation. For details, see `PKModelMap object`.
### Note
If using a `PKModelMap` object that specifies multiple doses, ensure each element in the `Dosed` property is unique.
`pkDataObj`
`PKData` object that defines the data to use in fitting, and the roles of the data columns used for estimation. For details, see `PKData object`.
### Note
For each subset of data belonging to a single group (as defined in the data column specified by the `GroupLabel` property), the software allows multiple observations made at the same time. If this is true for your data, be aware that:
• These data points are not averaged, but fitted individually.
• Different numbers of observations at different times cause some time points to be weighted more.
`InitEstimates`
Vector of initial parameter estimates for each parameter estimated in `pkModelMapObject`.`Estimated`. The length of `InitEstimates` must equal at least the length of `pkmodelMapObject`.`Estimated`. The elements of `InitEstimates` are transformed as specified by the `ParamTransform` name-value pair argument.
`optionStruct`
Structure containing fields and values used by the `options` input structure to the `nlinfit` function. The structure can also use the name-value pairs listed below as fields and values. Defaults for `optionStruct` are the same as for the `options` input structure to `nlinfit`, except for:
• `DerivStep` — Default is the lesser of `1e-4`, or the value of the `SolverOptions.RelativeTolerance` property of the configuration set associated with `modelObj`, with a minimum of `eps^(1/3)`.
• `FunValCheck` — Default is `off`.
If you have Parallel Computing Toolbox™, you can enable parallel computing for faster data fitting by setting the name-value pair argument `'UseParallel'` to `true` in the `statset` options structure as follows:
```parpool; % Open a parpool for parallel computing opt = statset(...,'UseParallel',true); % Enable parallel computing results = sbionlinfit(...,opt); % Perform data fitting```
### Name-Value Pair Arguments
Specify optional comma-separated pairs of `Name,Value` arguments. `Name` is the argument name and `Value` is the corresponding value. `Name` must appear inside quotes. You can specify several name and value pair arguments in any order as `Name1,Value1,...,NameN,ValueN`.
The `Name,Value` arguments are the same as the fields and values in the `options` structure accepted by `nlinfit`. For a complete list, see the `options` input argument in the `nlinfit` reference page in the Statistics and Machine Learning Toolbox™ documentation. The defaults for `Name,Value` arguments are the same as for the `options` structure accepted by `nlinfit`, except for:
• `DerivStep` — Default is the lesser of `1e-4`, or the value of the `SolverOptions.RelativeTolerance` property of the configuration set associated with `modelObj`, with a minimum of `eps^(1/3)`.
• `FunValCheck` — Default is `off`.
Following are additional `Name,Value` arguments that you can use with `sbionlinfit`.
`'ParamTransform'`
Vector of integers specifying a transformation function for each estimated parameter. The transformation function, `f`, takes `estimate` as an input and returns `beta`:
`beta = f(estimate)`
Each element in the vector must be one of these integers specifying the transformation for the corresponding value of `estimate`:
• `0````beta = estimate```
• `1``beta = log(estimate)` (default)
• `2````beta = probit(estimate)```
• `3````beta = logit(estimate)```
`'ErrorModel'`
Character vector specifying the form of the error term. Default is `'constant'`. Each model defines the error using a standard normal (Gaussian) variable e, the function value f, and one or two parameters a and b. Choices are:
• `'constant'`: y = f + a*e
• `'proportional'`: y = f + b*abs(f)*e
• `'combined'`: y = f + (a+b*abs(f))*e
• `'exponential'`: y = f*exp(a*e), or equivalently log(y) = log(f) + a*e
If you specify an error model, the `results` output argument includes an `errorparam` property, which has the value:
• a for `'constant'` and `'exponential'`
• b for `'proportional'`
• [a b] for `'combined'`
### Note
If you specify an error model, you cannot specify weights.
`'Weights'`
Either of the following:
• A matrix of real positive weights, where the number of columns corresponds to the number of responses. That is, the number of columns must equal the number of entries in the `DependentVarLabel` property of `pkDataObj`. The number of rows in the matrix must equal the number of rows in the data set.
• A function handle that accepts a vector of predicted response values and returns a vector of real positive weights.
### Note
If using a function handle, the weights must be a function of the response (dependent variable).
Default is no weights. If you specify weights, you cannot specify an error model.
`'Pooled'`
Logical specifying whether `sbionlinfit` does fitting for each individual (`false`) or if it pools all individual data and does one fit (`true`). If set to `true`, `sbionlinfit` uses the same model parameters for each dose level.
Default: `false`
## Output Arguments
`results` 1-by-N array of objects, where N is the number of groups in `pkDataObj`. There is one object per group, and each object contains these properties: `ParameterEstimates` — A `dataset` array containing fitted coefficients and their standard errors.`CovarianceMatrix` — Estimated covariance matrix for the fitted coefficients.`beta` — Vector of scalars specifying the fitted coefficients in transformed space.`R` — Vector of scalars specifying the residual values, where R(i,j) is the residual for the ith time point and the jth response in the group of data. If your model incudes: A single response, then `R` is a column vector of residual values associated with time points in the group of data. Multiple responses, then `R` is a matrix of residual values associated with time points in the group of data, for each response.`J` — Matrix specifying the Jacobian of the model, with respect to an estimated parameter, that is `$J\left(i,j,k\right)={\frac{\partial {y}_{k}}{\partial {\beta }_{j}}|}_{{t}_{i}}$`where ti is the ith time point, βj is the jth estimated parameter in the transformed space, and yk is the kth response in the group of data.If your model incudes: A single response, then `J` is a matrix of Jacobian values associated with time points in the group of data. Multiple responses, then `J` is a 3-D array of Jacobian values associated with time points in the group of data, for each response.`COVB` — Estimated covariance matrix for the transformed coefficients.`mse` — Scalar specifying the estimate of the error of the variance term.`errorparam` — Estimated parameters of the error model. This property is a scalar if you specify `'constant'`, `'exponential'`, or `'proportional'` for the error model. This property is a two-element vector if you specify `'combined'` for the error model. This property is an empty array if you specify weights using the `'Weights'` name-value pair argument. `SimDataI` `SimData object` containing data from simulating the model using estimated parameter values for individuals. This object includes observed states and logged states. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 1, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7762519717216492, "perplexity": 1894.5301212465483}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655886865.30/warc/CC-MAIN-20200705023910-20200705053910-00128.warc.gz"} |
https://www.allaboutcircuits.com/technical-articles/discontinuous-conduction-mode-of-simple-converters/ | Technical Article
# Discontinuous Conduction Mode of Simple Converters
June 11, 2015 by Editorial Team
## Discussed here are the discontinuous conduction mode, mode boundary, and conversion ratio of simple converters. During continuous conduction mode, the inductor current in the energy transfer never reaches zero value. In discontinuous conduction mode, the inductor current falls to zero level which is common in DC-to-DC converters.
Discussed here are the discontinuous conduction mode, mode boundary, and conversion ratio of simple converters.
Beginner
#### Origin of the Discontinuous Conduction Mode
During continuous conduction mode, the inductor current in the energy transfer never reaches zero value. In the case of the discontinuous conduction mode, the inductor current falls to zero level which is very common in DC-to-DC converters.
If the peak of the inductor current ripples is less than the DC component of the inductor current, the diode current is always positive and the diode is forced to turn on when the switch S (either a transistor or thyristor) is off. On the other hand, if the peak of the inductor current ripples becomes more than the DC component of the inductor current, the total current falls to zero value while the diode is conducting. Thus, the diode will stop conducting and the inductor current will remain at zero value until the switch S will be gated again due to the polarity reversal across the switch. This gives rise to the discontinuous conduction mode in the chopper or the DC-to-DC converter.
In the discontinuous conduction mode, inductor current is not persistent throughout the complete cycle and reaches zero level earlier even before the end of the period. Discontinuous conduction mode inductance is less than the minimum value of the inductance for the continuous conduction mode,
LDCM < LCCM.
Thus, this condition generally arises for the light-load condition.
Let the value of inductance in the case of the discontinuous conduction mode be,
LDCM=ξ LCCM where 0<ξ<1 for the discontinuous conduction.
The discontinuous conduction mode usually occurs in converters which consist of single-quadrant switches and may also occur in converters with two-quadrant switches. Two-level DC buck, and boost and buck-boost converters will be discussed further in this article. There are two levels indicated here towards the two-voltage level for the inductor voltage.
The energy stored in the inductor is proportional to the square of the current flowing through it. Having the same power through the converter, the requirement of the inductor current is higher in the case of the discontinuous conduction as compared to the continuous conduction mode. This causes more losses in the circuit of the discontinuous conduction. As the energy stored is not yet released to the output in the discontinuous conduction, the output gets affected by the ringing. This may also cause a noise in the discontinuous conduction mode.
Moreover, the value of the inductance required for discontinuous conduction mode is lesser as compared to the continuous conduction mode since it allows the fall of the inductor current to zero level. This causes higher values for the root-mean-square and the peak current. Thus, the size of the transformer required in isolated converters is bigger as compared to the continuous-conduction transformer size to suit the larger flux linkage and the losses.
Conversion ratio is independent of the load during the continuous conduction mode but when it enters in discontinuous conduction mode, it becomes dependent to the load. This complicates the DC-circuit analysis because the first-order equations become second order.
In most of the applications, continuous conduction mode is employed. Yet, discontinuous conduction mode can also be used for certain applications such as for the low-current and loop-compensation applications.
#### Buck Converter
Consider the simple buck converter circuit shown in Fig. 1. The current in the converter is controlled here by two switches labeled as S (MOSFET) and D (Diode).
Figure 1. Circuit for Buck Converter
This is a single-quadrant converter with the following waveforms for the continuous conduction mode shown in Fig. 2.
Figure 2. Supply Current IS, Diode Current ID, Inductor Current I, and Inductor Voltage VL Waveforms respectively (Buck Converter)
The buck converter in discontinuous and continuous conduction modes are in the second-order and first-order systems respectively.
For continuous conduction mode,
$$I_{L+}=\frac{1}{L}\int_{0}^{t}(V_{S}-V_{O})dt+I_{min}$$ For 0≤t≤DT.
$$\Rightarrow I_{L+} =\frac{V_{S}-V_{O}}{L}t+I_{min}$$
At t=DT, inductor current is at maximum value,
$$I_{max}=\frac{V_{S}-V_{O}}{L}DT+I_{min}$$ [Equation 1]
$$I_{L-}=(\frac{1}{L})\int_{DT}^{t}-V_{O} dt+I_{max}$$ For DT≤t≤T.
$$\Rightarrow I_{L-}=\frac{V_{O}}{L}(DT-t)+ I_{min}$$
The average value of the inductor current for the buck converter is
$$I_{avg}=\frac{V_{O}}{R}.$$
Because the inductor is always connected to the load whether the switch is on or off.
The average value of the current through the capacitor is nil due to the capacitor charge balance condition.
From Fig. 2, the area under the inductor current waveform is,
$$(Area)_{L} = T I_{min}+\frac{1}{2}T (I_{max}-I_{min})$$
Average value of the inductor current is,
$$I_{avg}=\frac{V_{O}}{R}=I_{min}+\frac{1}{2}(I_{max}-I_{min})$$ [Equation 2]
From Equations 1 and 2 we can get,
$$I_{avg}=\frac{V_{S}-V_{O}}{2L}DT+I_{min}$$
$$\Rightarrow I_{avg}=\frac{D(V_{S}-V_{O})}{2Lf}+ I_{min}=\frac{V_{O}}{R}$$
The value of inductance is,
$$L=\frac{D(V_{S}-V_{O})R}{2f(V_{O}-I_{min} R)}$$
The boundary of continuous condition is when Imin=0. If the value of Imin<0, the converter enters in the discontinuous conduction mode.
Thus,
L=LCCM for Imin=0
Hence,
$$L_{CCM}=\frac{D(V_{S}-V_{O})R}{2fV_{O}}$$
The value of inductance for the discontinuous conduction is given by
$$L=L_{DCM}=ξ L_{CCM}=\frac{ξD(V_{S}-V_{O})R}{2fV_{O}},$$ where 0<ξ<1.
For discontinuous conduction mode, when L< LCCM, the waveforms for the inductor current and inductor voltage are shown in Fig.3.
Figure 3. Inductor Current and Voltage for the Discontinuous Conduction Mode of Buck Converter
It is clear from the Fig.3 that the value of the minimum inductor current is zero i.e. Imin=0.
As the current across the inductor current is reduced to zero, the value of the voltage across the inductor is also reduced to zero value while VC =VO during the entire cycle.
For the time duration 0 ≤ t ≤ TON
$$I_{L+}(t)=\frac{V_{S}-V_{O}}{L}t$$ [Equation 3]
As the value of the peak inductor current occurs at t = TON,
$$\Rightarrow I_{max}=\frac{V_{S}-V_{O}}{L}T_{ON}=\frac{V_{S}-V_{O}}{L}DT=\frac{V_{S}-V_{O}}{Lf}D.$$
For the time duration TON ≤ t ≤ TX,
$$I_{L-}(t)=\int_{T_{ON}}^{t}-\frac{V_{C}}{L}dt+I_{max}$$
$$\Rightarrow I_{L-}(t)=\frac{V_{C}}{L}(T_{ON}-t)+\frac{V_{S}-V_{O}}{Lf}$$ [Equation 4]
At t = TX, current reduces to zero value,
$$0=\frac{V_{C}}{L}(T_{ON}-T_{X})+\frac{V_{S}-V_{O}}{Lf}$$
$$\Rightarrow T_{X}=D\frac{V_{S}}{f V_{O}}$$
Compared to the continuous condition, the amount of energy needed by the load is lesser in the discontinuous condition.
It is considered that the converter is operated in the steady state. Thus, the energy in the inductor remains the same at the start and at the end of the cycle. The volt-time balance condition can also be applied here.
The above equation can also be derived using the inductor volt-second balance condition as,
$$(V_{S}-V_{C})T_{ON}+(-V_{C})(T_{X}-T_{ON})=0$$
$$\Rightarrow (V_{S}-V_{C})DT+(-V_{C})(T_{X}-DT)=0$$
$$\Rightarrow T_{X}=V_{S}\frac{D}{f V_{O}}$$
For the time duration TX ≤ t ≤ T
$$I_{L0}(t)=0$$
From the Fig. 3, it is clear that the average value of the inductor current is equal to the area under the load current curve divided by T.
$$I_{avg}=\frac{\frac{1}{2}T_{X} I_{max}}{T}$$
For the DC supply,
$$I_{avg}=\frac{V_{O}}{R}$$
Hence,
$$\frac{V_{O}}{R}=\frac{V_{S}(V_{S}-V_{O})D^{2}}{2LV_{O} f}$$
The duty cycle ratio for the discontinuous conduction mode in the case of the buck converter is,
$$D=V_{O}\sqrt{\frac{2Lf}{R V_{S}(V_{S}-V_{O})}}$$ [Equation 5]
The duty cycle ratio of the buck converter in its continuous conduction mode is
$$D =\frac{V_{O}}{V_{i}}.$$
The duty cycle ratio for the buck converter is also dependent on the inductance L, load resistance R, and the switching frequency f.
For discontinuous conduction mode,
$$L=L_{DCM}=ξL_{CCM} =\frac{ξD(V_{S}-V_{O})R}{2fV_{O}}$$ [Equation 6]
Substitution of the Equation 5 into Equation 6 gives,
$$D=\frac{V_{O}}{V_{S}}\sqrt{ξ}$$ [Equation 7]
Since 0 < ξ < 1, duty cycle ratio of the buck converter in the discontinuous conduction mode is less than its value in the continuous conduction mode. Thus, less amount of energy is transferred through the converter which is not enough to maintain the inductor current throughout the entire period. This is the reason the discontinuous current flows through the inductor.
The conversion ratio of buck DC-to-DC converter is,
$$\frac{V_{O}}{V_{S}}=\frac{D}{\sqrt{ξ}}$$
where 0<ξ<1
If the value of ξ is greater than 1, the converter enters in the continuous conduction mode. We can easily know the conduction state of the buck converter, which is either continuous or discontinuous, if we know the value of input and output voltages of the converter by simply measuring the value of ξ.
Instantaneous value of the capacitor current is given by subtracting the value of the inductor current to the load current. When the inductor current value is reduced to zero value, the load current is supplied by the capacitor.
From Equations 3 and 4 we can get:
For the time duration 0 < t
$$I_{C+}(t)=\frac{V_{S}-V_{O}}{L}t-I_{O}$$ [Equation 8]
For the time duration DT < t < TX,
$$I_{C-}(t)=\frac{V_{O}}{L}(DT-t)+\frac{D(V_{S}-V_{O})}{Lf}-I_{O}$$ [Equation 9]
And for the time duration TX < t < T,
$$I_{C_{O}}=-I_{O}$$ [Equation 10]
If the capacitance is assumed to be ideal, the capacitor current will not decay even after the inductor current value is reduced to zero value. For that case, the waveforms for the capacitor and inductor current are shown in Fig. 4.
From Fig.4, it is clear that the value of the capacitor current is zero at time t=Ta and at t=Tb.
Equation 8 at time t =Ta gives,
$$0=\frac{V_{S}-V_{O}}{L}T_{a}-I_{O}$$
$$\Rightarrow T_{a}=L\frac{I_{O}}{V_{S}-V_{O}}$$ [Equation 11]
And Equation 9 at time t=Tb gives,
$$0=\frac{V_{O}(DT-T_{b})}{L}+\frac{D(V_{S}-V_{O})}{Lf}-I_{O}$$
$$\Rightarrow T_{b}=DT-\frac{LI_{O}}{V_{O}}+\frac{D(V_{S}-V_{O})}{fV_{O}}$$ [Equation 12]
Figure 4. Inductor Current and Capacitor Current respectively for the Discontinuous Conduction Mode
of the Buck Converter
The positive time interval for the charge accumulation i.e. Tb-Ta from Equations 11 and 12 is given by:
$$T_{b}-T_{a}=D\frac{V_{S}}{fV_{O}}-\frac{LI_{O}V_{S}}{V_{O}(V_{S}-V_{O})}$$ [Equation 13]
From Equation 6 and Equation 7 we can get,
$$T_{b}-T_{a}=\frac{2\sqrt{ξ}-ξ}{2f}$$ [Equation 14]
From Fig.4, it is also clear that the maximum value of the capacitor current occurs at the time t=DT.
At t = DT,
IC(DT) = Ihp
From Equation 8 we can get,
$$I_{hp} = (\frac{2}{\sqrt{\xi}}-1)I_{O}$$ [Equation 15]
The charge accumulated is the integration of the capacitor current (area under the capacitor current from Ta to Tb) which is also given by the expression:
∆Q=C∆V [Equation 16]
Thus,
$$C ∆V=\frac{1}{2}(2\sqrt{ξ}-ξ)(\frac{2}{\sqrt{ξ}}-1)I_{O}(\frac{1}{2f})=\frac{V_{O}(2-\sqrt{ξ})^2}{4Rf}$$
The ripples in the load due to the ripples in the capacitor are given by the following expression:
$$r=\frac{∆V}{V_{O}}=\frac{(2-\sqrt{ξ})^2}{4Rf}$$
#### Boost Converter
Circuit for the boost converter is shown in Fig. 5.
Figure 5. Circuit for Boost Converter
The waveform for the continuous conduction mode is shown in Fig. 6. When it is in the discontinuous conduction mode, the waveform is shown in Fig. 7.
We can assume that the inductor is connected to the load for the time Ty such that
IO =Y Iavg [Equation 17]
where
Y = Ty/T
Figure 6. Supply Current, Diode Current, Inductor Current and Inductor Voltage respectively (Boost Converter)
Figure 7. Inductor Current and Voltage for the Discontinuous Conduction Mode of Boost Converter
When the converter operates in the steady-state condition, the energy at the start and at the end of the cycle is the same. Thus, volt-time balance condition can be applied here too.
From the figure and the volt-time balance condition it is clear that,
TON VS+(TX-TON).(VS-VC)=0
$$\Rightarrow DT V_{S}+(T_{X}-DT).(V_{S}-V_{O})=0$$
$$\Rightarrow T_{X}=D\frac{V_{O}}{(V_{S}-V_{O})f}$$
From Fig. 6, it is also evident that the value of the minimum and maximum currents are as follows:
Imin=0;
and
$$I_{max}=\frac{V_{S}}{L}T_{ON}=\frac{V_{S}}{Lf}D$$
Thus, the average value of the inductor current is,
$$I_{avg}=\frac{1}{1-D}\frac{V_{O}}{R}=\frac{\frac{1}{2}T_{X}I_{max}}{T}$$
$$\Rightarrow \frac{V_{O}}{R}=\frac{(\frac{1}{2})(\frac{DV_{O}}{(V_{S}-V_{O})f})(\frac{V_{S}D}{Lf})(1-D)}{T}$$
From Equation 17 we can get,
$$D=\sqrt{2\frac{(V_{O}-V_{S})Lf}{RYV_{S}}}$$ [Equation 18]
The duty cycle ratio of the buck converter for the continuous conduction mode is equal to $$\frac{V_{O}-V_{S}}{V_{S}}.$$
In the discontinuous conduction mode, the duty cycle ratio of the boost converter is not only dependent on the input and output voltages but it also depends on the inductance L, load resistance R, and the switching frequency f.
The discontinuous inductance for the boost converter is,
$$L_{DCM}=ξY R\frac{V_{S}(V_{O}-V_{S})}{2 f V_{O}}$$
Substituting this value of inductance in Equation 18 we can get,
$$D=\frac{V_{O}-V_{S}}{V_{O}}\sqrt{ξ}$$
$$\Rightarrow \frac{V_{O}}{V_{S}}=\frac{V_{S}}{1-\frac{D}{\sqrt{ξ}}}$$
Hence, the complete conversion ratio for the boost converter in the discontinuous conduction mode is given by the above expression.
#### Buck-Boost Converter
The circuit for the buck-boost converter is shown in Fig. 8 and the related waveforms of the buck-boost converter in the case of continuous conduction mode are shown in Fig. 9.
Figure 8. Circuit for the Buck-Boost Converter
Inductor is connected to the load during the switch-off period; where Y= (1-D).
Thus,
$$I_{avg}=Y I_{O}=Y\frac{V_{O}}{R}=\frac{(1-D)V_{O}}{R}$$
Figure 9. Supply Current, Diode Current, Inductor Current and Inductor Voltage respectively (Buck-Boost Converter) in Continuous Conduction Mode
Figure 10. Inductor Current and Inductor Voltage for the Discontinuous Conduction Mode
of the Buck-Boost Converter
Assume that the converter is operating in steady state; therefore, energy at the start up to the end of the cycle must be equal. Thus, volt-time balance condition is applied here.
Applying the volt-sec balance across the inductor using the Fig. 9,
VS TON + (TX - TON) (-VO) = 0
$$\Rightarrow V_{S}DT - (T_{X}-DT)V_{O}=0$$
$$\Rightarrow T_{X} = \frac{D(V_{S}+V_{O})}{V_{O}f}$$
From the Fig. 9, it is also noticed that the value of the minimum and maximum currents are as follows:
Imin = 0
$$I_{max}=\frac{V_{S}}{L}T_{ON}=\frac{V_{S}}{Lf}D$$
Thus, the average value of the inductor current is,
$$I_{avg} = Y\frac{V_{O}}{R} = \frac{\frac{1}{2}I_{max}T_{X}}{T}$$
$$\Rightarrow \frac{V_{O}}{R}=\frac{\frac{\frac{1}{2}V_{S}D}{Lf}D(V_{S}+V_{O})}{YV_{O}f}f$$
In the discontinuous conduction mode of the buck-boost converter, the value of the duty cycle ratio is given by
$$D=V_{O}\sqrt{\frac{2Lf}{R YV_{S}(V_{S}+V_{O})}}$$
The duty cycle ratio of the buck-boost converter for the continuous conduction mode is equal to $$\frac{V_{O}}{V_{O}+V_{S}}.$$
In the case of the discontinuous conduction mode, the duty cycle ratio of the buck-boost converter is also dependent on the inductance L, load resistance R, and the switching frequency f.
The conversion ratio for the buck-boost converter is,
$$\frac{V_{O}}{V_{S}}=\frac{D}{\sqrt{ξ}-D}$$
• Share
### You May Also Like
1 Comment
• S
Sajeel Ahmed February 22, 2018
This article has realized me to think something new. I am working on boost converter TPS61030 and It produces noise and ringing maybe due to the discontinous conduction mode and I want to solve this issue because I want silent device. Is to possible to operate it in continuous conduction mode by using the formula had been derived in this article?
Like. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8916910290718079, "perplexity": 1398.3238837750553}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-40/segments/1600400208095.31/warc/CC-MAIN-20200922224013-20200923014013-00131.warc.gz"} |
https://www.calculus-online.com/exercise/5977 | Calculating Limit of Function – An exponential function divided by a polynomial – Exercise 5977
Exercise
Evaluate the following limit:
$$\lim _ { x \rightarrow 0} \frac{e^{2x}-1}{3x}$$
$$\lim _ { x \rightarrow 0} \frac{e^{2x}-1}{3x}=\frac{2}{3}$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 2, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3208426833152771, "perplexity": 1123.022734217076}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296950422.77/warc/CC-MAIN-20230402074255-20230402104255-00302.warc.gz"} |
https://simple.wikipedia.org/wiki/Vector_field | # Vector field
Part of a vector field
A vector field is a function that assigns to every point in space a vector. It can be imagined as a collection of arrows, each one attached to a different point in space. For example, the wind (the velocity of air) can be represented by a vector field. This is because in every point one can write an arrow showing the direction of the wind and its strength.
Vector calculus is the study of vector fields.
## Physical examples
In everyday life, gravity is the force that makes objects fall down. More generally, it is the force that pulls objects towards each other. If we describe for each point in space the direction and strength of the earth's pull, we will get a gravity vector field for the Earth.
The theory dealing with electricity and magnetism in physics is called electromagnetism. One of the basic assumptions is that there are two vector fields in all space which govern electric and magnetic forces. One is the electric field, which is often written as ${\displaystyle {\vec {E}}}$ and the second is the magnetic field, which is often written as ${\displaystyle {\vec {B}}}$.
Atmospheric circulation can be represented by a vector field. The more precisely the vector field describes the actual flow, the better the resulting weather forecast. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 2, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9685376882553101, "perplexity": 162.32054814446255}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764499888.62/warc/CC-MAIN-20230131154832-20230131184832-00783.warc.gz"} |
http://philpapers.org/s/Patricia%20J.%20Carlson | ## Search results for 'Patricia J. Carlson' (try it on Scholar)
1000+ found
Order:
1. Patricia J. Carlson & Frances Burke (1998). Lessons Learned From Ethics in the Classroom: Exploring Student Growth in Flexibility, Complexity and Comprehension. [REVIEW] Journal of Business Ethics 17 (11):1179-1187.
This study shows the link between teaching ethics in a college setting and the evolution of student thinking about ethical dilemmas. At the beginning of the semester, students have a rigid "black and white" conception of ethics. By the end of the semester, they are thinking more flexibly about the responsibilities of leaders in corporate ethical dilemmas, and they are able to appreciate complex situations that influence ethical behavior. The study shows that education in ethics produces more "enlightened" consumers of (...)
Export citation
My bibliography 12 citations
2. Mark S. Blodgett & Patricia J. Carlson (1997). Corporate Ethics Codes: A Practical Application of Liability Prevention. [REVIEW] Journal of Business Ethics 16 (12-13):1363-1369.
With the great increase in litigation, insurance costs, and consumer prices, both managers and businesses should take a proactive position in avoiding liability. Legal liability may attach when a duty has been breached; many actions falling into this category are also considered unethical. Since much of business liability is caused by a breach of a duty by a business to either an individual, another business, or to society, this article asserts that the practice of liability prevention is a practical business (...)
Export citation
My bibliography 8 citations
3. Elof Axel Carlson (1971). An Unacknowledged Founding of Molecular Biology: H. J. Muller's Contributions to Gene Theory, 1910-1936. [REVIEW] Journal of the History of Biology 4 (1):149 - 170.
Export citation
My bibliography 1 citation
4. E. A. Ea Carlson (1984). H. J. Muller: The Role of Scientist in Creating and Applying Knowledge. Social Research 51 (3):763.
No categories
Export citation
My bibliography
5. Elof Axel Carlson (1971). An Unacknowledged Founding of Molecular Biology: H. J. Muller's Contributions to Gene Theory, 1910?1936. Journal of the History of Biology 4 (1):149-170.
Export citation
My bibliography
6.
Export citation
My bibliography
Export citation
My bibliography 1 citation
8. George J. Friedman & John G. Carlson (1973). Effects of a Stimulus Correlated with Positive Reinforcement Upon Discrimination Learning. Journal of Experimental Psychology 97 (3):281.
Export citation
My bibliography
9. Rose F. Caron, Albert J. Caron, V. R. Carlson & Lynne S. Cobb (1979). Perception of Shape-at-a-Slant in the Young Infant. Bulletin of the Psychonomic Society 13 (2):105-107.
Export citation
My bibliography
10. Timothy J. Carlson (2003). Ranked Partial Structures. Journal of Symbolic Logic 68 (4):1109-1144.
The theory of ranked partial structures allows a reinterpretation of several of the standard results of model theory and first-order logic and is intended to provide a proof-theoretic method which allows for the intuitions of model theory. A version of the downward Löwenheim-Skolem theorem is central to our development. In this paper we will present the basic theory of ranked partial structures and their logic including an appropriate version of the completeness theorem.
Export citation
My bibliography
11. Timothy J. Carlson (1999). Ordinal Arithmetic and [Mathematical Formula]-Elementarity. Archive for Mathematical Logic 7.
Export citation
My bibliography 8 citations
12. Timothy J. Carlson (2009). Patterns of Resemblance of Order 2. Annals of Pure and Applied Logic 158 (1):90-124.
We will investigate patterns of resemblance of order 2 over a family of arithmetic structures on the ordinals. In particular, we will show that they determine a computable well ordering under appropriate assumptions.
Export citation
My bibliography 3 citations
13. Kurt A. Carlson & J. Edward Russo (2001). Biased Interpretation of Evidence by Mock Jurors. Journal of Experimental Psychology: Applied 7 (2):91.
No categories
Export citation
My bibliography 5 citations
14. Timothy J. Carlson (1999). Ordinal Arithmetic and Sigma_{1}-Elementarity. Archive for Mathematical Logic 38 (7):449-460.
We will introduce a partial ordering $\preceq_1$ on the class of ordinals which will serve as a foundation for an approach to ordinal notations for formal systems of set theory and second-order arithmetic. In this paper we use $\preceq_1$ to provide a new characterization of the ubiquitous ordinal $\epsilon _{0}$.
Export citation
My bibliography 4 citations
15. Timothy J. Carlson & Gunnar Wilken (2012). Normal Forms for Elementary Patterns. Journal of Symbolic Logic 77 (1):174-194.
A notation for an ordinal using patterns of resemblance is based on choosing an isominimal set of ordinals containing the given ordinal. There are many choices for this set meaning that notations are far from unique. We establish that among all such isominimal sets there is one which is smallest under inclusion thus providing an appropriate notion of normal form notation in this context. In addition, we calculate the elements of this isominimal set using standard notations based on collapsing functions. (...)
Export citation
My bibliography 1 citation
16. Erik Carlson & Erik J. Olsson (2001). The Presumption of Nothingness. Ratio 14 (3):203–221.
No categories
Export citation
My bibliography 1 citation
17. Thomas A. Carlson, Robert Rauschenberger & Frans A. J. Verstraten (2007). No Representation Without Awareness in the Lateral Occipital Cortex. Psychological Science 18 (4):298-302.
Export citation
My bibliography 1 citation
18. Carl E. Carlson & Ian J. Swanson (2000). Casimir Energy in Astrophysics: Gamma-Ray Bursts From QED Vacuum Transitions. [REVIEW] Foundations of Physics 30 (5):775-783.
Motivated by analogous applications to sonoluminescence, neutron stars mergers are examined in the context of Schwinger's dynamical Casimir effect. When the dielectric properties of the QED vacuum are altered through the introduction of dense matter, energy shifts in the zero-point fluctuations can appear as photon bursts at gamma-ray frequencies. The amount of radiation depends upon the properties and amount of matter in motion and the suddenness of the transition. It is shown that the dynamical Casimir effect can convert sufficient energy (...)
Export citation
My bibliography
19. Timothy J. Carlson (2011). On the Conservativity of the Axiom of Choice Over Set Theory. Archive for Mathematical Logic 50 (7-8):777-790.
We show that for various set theories T including ZF, T + AC is conservative over T for sentences of the form ${\forall x \exists ! y}$ A(x, y) where A(x, y) is a Δ0 formula.
Export citation
My bibliography
20.
Export citation
My bibliography 1 citation
21. Timothy J. Carlson & Gunnar Wilken (2012). Tracking Chains of Σ2-Elementarity. Annals of Pure and Applied Logic 163 (1):23-67.
Export citation
My bibliography
22. No categories
Export citation
My bibliography
23. Patrick J. Carroll, James A. Shepperd, Kate Sweeny, Erika Carlson & Joann P. Benigno (2007). Disappointment for Others. Cognition and Emotion 21 (7):1565-1576.
Export citation
My bibliography
24. Background: The Declaration of Helsinki, the World Medical Association’s statement of ethical guidelines regarding medical research, is published in the three official languages of the WMA: English, French and Spanish.Methods: A detailed comparison of the three official language versions was carried out to determine ways in which they differed and ways in which the wording of the three versions might illuminate the interpretation of the document.Results: There were many minor linguistic differences between the three versions. However, in paragraphs 1, 6, (...)
Export citation
My bibliography
25. Erik Carlson & Erik J. Olsson (1998). Is Our Existence in Need of Further Explanation? Inquiry 41 (3):255 – 275.
Several philosophers have argued that our cosmos is either purposely created by some rational being(s), or else just one among a vast number of actually existing cosmoi. According to John Leslie and Peter van Inwagen, the existence of a cosmos containing rational beings is analogous to drawing the winning straw among millions of straws. The best explanation in the latter case, they maintain, is that the drawing was either rigged by someone, or else many such lotteries have taken place. Arnold (...)
No categories
Export citation
My bibliography
26. H. B. Carlson & A. J. Ebel (1944). A Dual Selective Amplifier. Journal of Experimental Psychology 34 (3):253.
Export citation
My bibliography
27. Timothy J. Carlson (2000). Review: Michael Rathjen, Recent Advances in Ordinal Analysis: $Prod_{2}^{1}$-$CA$ and Related Systems. [REVIEW] Bulletin of Symbolic Logic 6 (3):357-358.
Export citation
My bibliography
Export citation
My bibliography
29. T. J. Carlson (1951). A Note on the History of Philosophy. Journal of Philosophy 48 (5):127-129.
Export citation
My bibliography
30. No categories
Export citation
My bibliography
31. M. Carlson & J. Carney (1993). I Didn't Get Hired to Fix Everything.'. In Jonathan Westphal & Carl Avren Levenson (eds.), Time. Hackett Pub. Co. 142--13.
No categories
Export citation
My bibliography
Export citation
My bibliography
33.
Export citation
My bibliography
34. This book examines influential conceptions of sport and then analyses the interplay of challenging borderline cases with the standard definitions of sport. It is meant to inspire more thought and debate on just what sport is, how it relates to other activities and human endeavors, and what we can learn about ourselves by studying sport.
Export citation
My bibliography
Export citation
My bibliography
36. J. Edward Russo, Kurt A. Carlson, Margaret G. Meloy & Kevyn Yong (2008). The Goal of Consistency as a Cause of Information Distortion. Journal of Experimental Psychology: General 137 (3):456-470.
Export citation
My bibliography
Export citation
My bibliography
Export citation
My bibliography
39. W. J. (1995). E.-J. Marey's Visual Rhetoric and the Graphic Decomposition of the Body. Studies in History and Philosophy of Science Part A 26 (2):175-204.
Export citation
My bibliography
40. Dwight J. Ingle (1979). Anton J. Carlson: A Biographical Sketch. Perspectives in Biology and Medicine 22 (2-2):S114-S137.
Export citation
My bibliography
Export citation
My bibliography
42. No categories
Export citation
My bibliography
43. Lester R. Dragstedt (1964). An American by Choice: A Story About Dr. A. J. Carlson. Perspectives in Biology and Medicine 7 (2):145-158.
Export citation
My bibliography
44. Krysten Latham (1978). The End of Medicine by Rick J. Carlson. Perspectives in Biology and Medicine 21 (4):634-635.
Export citation
My bibliography
45. Noëlle McAfee (2001). Book Review: Patricia J. Huntington. Ecstatic Subjects, Utopia, and Recognition: Kristeva, Heidegger, Irigaray. New York: Suny Press, 1998. [REVIEW] Hypatia: A Journal of Feminist Philosophy 16 (2):100-103.
Export citation
My bibliography
46. James J. Sosnoski (forthcoming). Patricia Harkin James J. Sosnoski. Intertexts: Reading Pedagogy in College Writing Classrooms.
Translate
Export citation
My bibliography
47. No categories
Export citation
My bibliography
48. Translate | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7740676999092102, "perplexity": 8520.412326176394}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-50/segments/1480698542714.38/warc/CC-MAIN-20161202170902-00059-ip-10-31-129-80.ec2.internal.warc.gz"} |
http://codereview.stackexchange.com/questions/56805/is-this-fizzbuzz-swift-y | # Is this FizzBuzz Swift-y?
for (var i = 1; i <= 100; ++i) {
var fizzBuzz = ""
if i % 3 == 0 {
fizzBuzz += "Fizz"
}
if i % 5 == 0 {
fizzBuzz += "Buzz"
}
if fizzBuzz == "" {
fizzBuzz += "\(i)"
}
println(fizzBuzz)
}
I don't really like comparing strings with ==, but apparently, that's how you do it in Swift (and there's not another option).
The parenthesis in if statements are optional in Swift. Should that be a thing, or should we stick with them? The curly-braces were optional in Objective-C (and lots of programming languages) but they're not in Swift. Despite their former optionality, I never thought it was a good idea to not use them--is it a good idea to not use parenthesis here?
Not explicitly declaring the type of variable is now a thing in Swift (although the variable still has an explicit type, it's just implicitly determined). Is it okay to let the type be implicitly determined, or should we stick with explicitly declaring the type?
-
Is this FizzBuzz Swift-y?
Kinda, but it could be a lot better. Here's what I would do to fix it:
• Extrapolate this code into a method, then call the method from the for loop.
func fizzbuzz(i: Int) -> String
{
// ...
}
• There is a handy Swift feature called "Tuples". Tuples are groupings of values. We can use them to represent our results from the modulo operation.
let result = (i % 3, i % 5)
• Now that we are using a Tuple to represent the result, we can easily use a switch to perform the necessary actions.
switch result
{
case (0, 0):
return "FizzBuzz"
case (0, _):
return "Fizz"
case (_, 0):
return "Buzz"
default:
return "\(i)"
}
You might be wondering what that underscore is. That _ is used to indicate a discarded value that we don't really care about, the value in the tuple that doesn't really matter to us in the evaluation.
• Your for loop isn't very "Swift-y". Here's how I would write is so that it calls the function 100 times.
for number in 1...100
{
println(fizzbuzz(number))
}
• The parenthesis in if statements are optional in Swift. Should that be a thing, or should we stick with them?
This is a very style-oriented question. Style differs from person to person, and is very organic. Since no "style rules" have been put in place, do whatever you are most comfortable with.
• The curly-braces were optional in Objective-C (and lots of programming languages) but they're not in Swift.
This was implemented in order to prevent simplified if conditional statements and the class of bugs that associated with them. For example:
if (someCondition)
doThisForSomeCondition()
doThisAsWell()
if (someOtherCondition)
// ...
Swift's forced usage of braces eliminated the execution of doThisAsWell() outside of the someCondition conditional statement.
• Is it okay to let the type be implicitly determined, or should we stick with explicitly declaring the type?
Whether or not you include the explicit type is a matter of taste. In some contexts it might make your code more readable. However, this is usually not the case; and since the compiler will almost never assign the wrong type to your variable, I usually leave the type to be implicitly determined. Whatever way you decide will not affect speed/efficiency of the code, so that is not a factor.
-
Is there a 'precedence' in the switch operator...? Should the (0,0) case be before the (0,_) and (_,0) cases? – rolfl Jul 12 at 1:47
@rolfl You are correct according to the documentation. Edit has been made. – syb0rg Jul 12 at 2:17
+1 for the for number in 1...100 suggestion. I don't think the tuple and switch implementation is an improvement over the original. Tuples are useful sometimes, but I don't think this is one of those times. I see code duplication; "Fizz" and "Buzz" appear twice now. Also, the tuple solution gets clumsy if you try to extend it to "FizzBuzzPling" as suggested here: codereview.stackexchange.com/questions/56708/… – GraniteRobert Jul 12 at 2:24
@GraniteRobert This is due to the design of the language: "In contrast with switch statements in C and Objective-C, switch statements in Swift do not fall through the bottom of each case and into the next one by default. Instead, the entire switch statement finishes its execution as soon as the first matching switch case is completed, without requiring an explicit break statement." If the design were more C-like, it would be a lot less awkward to extend it. – syb0rg Jul 12 at 2:36
We're not talking about Ruby--we're talking about Swift. :/ – nhgrif Jul 12 at 12:06
In a for loop in Swift, the parentheses are optional, and from all of Apple's book and sample code, they are usually omitted--you did so yourself on the if statements. Furthermore, Swift has a range operator (two, in fact), so you should use that instead of the manual increments anyway.
for i in 1...100 {
...
}
For better or worse, == 0 is the only way to do the comparison in Swift, and many would argue it's easier to read in C/ObjC anyway.
-
Optional Parentheses
I haven't seen any good reasons to use parentheses where Swift says they are optional. It makes no more sense to use them in an if or for than it does in a simple math expression like foo = (x + y). Or the C incantation that some folks believe has mysterious powers: return (foo);
If you want your Swift to look more like C, go a head an add the optional parentheses. But that seems an unworthy goal to me, and doomed to failure. :-)
Comparison with ==
I have the opposite view; strings are ordinary objects in Swift, the ordinary comparison operators like == seem reasonable to me. Building Objective-C on top of C forced some weird idioms on us. I'm willing to let them go.
-
A couple of observations around these lines…
if fizzBuzz == "" {
fizzBuzz += "\(i)"
}
• This seems like an unjustified use of string interpolation. String(i) would be more direct.
• Why bother concatenating to an empty string?
With those two changes…
if fizzBuzz == "" {
fizzBuzz = String(i)
}
-
I don't know if this is Swift-y or Ug-ly, or maybe both.
I tried to make something similar to OldCurmudgeon's data-centric FizzBuzzPling extension in Java I didn't get far with enum, but found a way to implement it with struct:
struct FizzBuzz
{
var s: String
var n: Int
init(_ s: String, _ n: Int)
{
self.s = s
self.n = n
}
func fizz(number: Int) -> String
{
return (number % self.n) == 0 ? self.s : ""
}
}
let fizzBuzzArray = [FizzBuzz("Fizz", 3),
FizzBuzz("Buzz", 5),
FizzBuzz("Pling", 7)]
func fizzbuzz(number: Int) -> String
{
var result = ""
for fb in fizzBuzzArray
{
result += fb.fizz(number)
}
return (result == "") ? String(number) : result
}
for number in 1...106
{
println(fizzbuzz(number))
}
The initializer for FizzBuzzArray seems too verbose, but I don't know a way to simplify it.
I borrowed the String(number) suggestion from 200_success.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4974309802055359, "perplexity": 2669.1491802559685}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802768497.135/warc/CC-MAIN-20141217075248-00002-ip-10-231-17-201.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/165479/chain-rule-confusion | Chain Rule Confusion
Below i have a function that i need to use the chain rule on. My friend showed me his answer which was correct which was $-8x^7\sin(a^8+x^8)$.
$$y = \cos(a^8 + x^8)$$
I am really confused as how he got that. I know that in the chain rule you bring whats outside to the front. So why is $a^8$ not in this solution?
-
What is the derivative of a constant? – M.B. Jul 1 '12 at 22:19
Use \cos and \sin. – Did Jul 1 '12 at 22:32
SO a is a constant? How do i know this though? – soniccool Jul 2 '12 at 1:13
It's really something you have to pick up from context (i.e. the bit of the question which isn't the equation). If you're trying to work out $dy/dx$, anything which doesn't involve either $y$ or $x$ is a constant. If you're trying to work out $dz/dt$, then something involving $x$ would be a constant. Really this is all an unfortunate consequence of sloppy notation. – Ben Millwood Jul 2 '12 at 2:17
You’re trying to treat the chain rule as a mechanical manipulation of symbols instead of understanding what it actually says. It says that when you differentiate a composite function, say $g\big(f(x)\big)$, you first take the derivative of $g$ as if $f(x)$ were the independent variable, and then you multiply by $f\,'(x)$.
Here you have $h(x)=\cos(a^8+x^8)$, and you want $h'(x)$. First pretend that what’s inside the cosine is a single variable; call it $u$, if you like so that $u=a^8+x^8$ and $h(x)=\cos u$. Now differentiate with respect to $u$ to get $-\sin u$. But you weren’t really differentiating with respect to $u$: you were differentiating with respect to $x$. The chain rule says that in order to compensate for this distinction, you must now multiply by $\frac{du}{dx}$. Since $a^8$ is a constant, its derivative (with respect to anything!) is $0$, and therefore $\frac{du}{dx}=8x^7$. The chain rule now tells you that $$h'(x)=\Big(-\sin(a^8+x^8)\Big)\Big(8x^7\Big)=-8x^7\sin(a^8+x^8)\;.$$
Question though, how do i know $a^8$ is a constant? Or just memorize that a in a derivative is a constant? – soniccool Jul 2 '12 at 1:14
No, a is a constant because the expression is derived regarding x. If it were $\frac{du}{da} then x were the constant, and a the variable. – vsz Jul 2 '12 at 6:07 @vsz: Nowhere in the problem as relayed by the OP does it specify that the differentiation is with respect to$x$; we can only infer that from convention (and the friend’s correct answer). Moreover, the fact that the differentiation is w.r.t.$x$is not sufficient to rule out the possibility that$a$is itself some function of$x$, and that the correct is actually$-8(a^7a'+x^7)\sin(a^8+x^8)$. Again, only our knowledge of convention and of what’s likely to appear in a problem at this level lets us answer correctly. – Brian M. Scott Jul 2 '12 at 16:55 Note that$y$is a function of$x$and$a$is just a constant. To understand the procedure, let us call$x^8 + a^8$as a function$f(x)$. We then have $$y = \cos(f(x))$$ Hence, by chain rule we get that $$\dfrac{dy}{dx} = \dfrac{dy}{df} \times \dfrac{df}{dx}$$ Now$\dfrac{dy}{df} = -\sin(f(x))$and$\dfrac{df(x)}{dx} = \dfrac{d(x^8 + a^8)}{dx} = \dfrac{d(x^8)}{dx} + \dfrac{d(a^8)}{dx}$. Now recall that $$\dfrac{d (x^n)}{dx} = n x^{n-1} \text{ and } \dfrac{d (\text{ constant })}{dx} = 0$$ Hence, we get that$\dfrac{d(x^8)}{dx} + \dfrac{d(a^8)}{dx} = 8 x^7 + 0 = 8x^7$. Hence, we get that $$\dfrac{dy}{dx} = \dfrac{dy}{df} \times \dfrac{df}{dx} = - \sin(f(x)) \times \left(8x^7 \right) = - 8x^7 \sin \left( x^8+a^8 \right)$$ - HINT What is the derivative of$a^8+x^8$? It doesn't have any$a$term either. - The fact that$a$is a constant is one of those things you have to infer from context. Typically, in single variable calculus, one uses letters towards the end of the alphabet are all dependent on one another (typically the relationship is they are all functions of$x$,$t$, or$z$), and other letters without prior meaning (e.g.$f$and$g$) as constants. One can use$a$as a variable functionally dependent on$x$. If$a$is used that way in the stated problem, then you would have another term in the answer that includes a factor of$\frac{da}{dx}\$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9922348260879517, "perplexity": 416.157730256694}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1429246661364.60/warc/CC-MAIN-20150417045741-00279-ip-10-235-10-82.ec2.internal.warc.gz"} |
http://link.springer.com/article/10.2307%2F1352447 | , Volume 16, Issue 4, pp 887-897
# Biomass and production of benthic microalgal communities in estuarine habitats
Rent the article at a discount
Rent now
* Final gross prices may vary according to local VAT.
## Abstract
Accurate measures of intertidal benthic microalgal standing stock (biomass) and productivity are needed to quantify their potential contribution to food webs. Oxygen microelectrode techniques, used in this study, provide realistic measures of intertidal benthic microalgal production. By dividing a salt-marsh estuary into habitat types, based on sediment and sunlight characteristics, we have developed a simple way of describing benthic microalgal communities. The purpose of this study was to measure and compare benthic microalgal biomass and production in five different estuarine habitats over an 18-mo period to document the relative contributions of benthic microalgal productivity in the different habitat types. Samples were collected bimonthly from April 1990 to October 1991. Over the 18-mo period, tall Spartina zone habitats had the highest (101.5 mg chlorophyll a (Chl a) m−2±6.9 SE) and shallow subtidal habitats the lowest (60.4±8.9 SE) microalgal biomass. There was a unimodal peak in biomass during the late winter-early spring period. The concentrations of photopigments (Chl a and total pheopigments) in the 0–5 mm of sediments were highly correlated (r2=0.73 and 0.88, respectively) with photopigment concentrations in the 5–10 mm depth interval. Biomass specific production (μmol O2 mg Chl a −1 h−1) was highest in intertidal mudflat habitats (206.3±11.2 SE) and lowest in shallow subtidal habitats (104.3±11.1 SE). Regressions of maximum production (production at saturating irradiances) vs. biomass (Chl a) in the upper 2 mm of sediment by habitat type gave some of the highest correlations ever reported for benthic microalgal communities (r2 values ranged from 0.43 to 0.73). The habitat approach and oxygen microelectrode techniques provide a useful, realistic ranged from 0.43 to 0.73). The habitat approach and oxygen microelectrode techniques provide a useful, realistic method for understanding the biomass and production dynamics of estuarine benthic microalgal communities. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8267917037010193, "perplexity": 16273.284526412379}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042981460.12/warc/CC-MAIN-20150728002301-00079-ip-10-236-191-2.ec2.internal.warc.gz"} |
https://www.groundai.com/project/an-axiomatic-basis-for-blackwell-optimality/ | An axiomatic basis for Blackwell optimality
# An axiomatic basis for Blackwell optimality
Adam Jonsson Department of Engineering Sciences and Mathematics
Luleå University of Technology, 97187 Luleå, Sweden
###### Abstract.
In the theory of Markov decision processes (MDPs), a Blackwell optimal policy is a policy that is optimal for every discount factor sufficiently close to one. This paper provides an axiomatic basis for Blackwell optimality in discrete-time MDPs with finitely many states and finitely many actions.
###### Key words and phrases:
Markov decision processes; Blackwell optimality
###### 2010 Mathematics Subject Classification:
Primary 90C40, Secondary 91B06
## 1. Introduction
In his foundational paper, Blackwell [4] showed that for any discrete-time Markov decision process (MDP) with finitely many states and finitely many actions, there exists a stationary policy that is optimal for every discount factor sufficiently close to one. Following Veinott [15], policies that possess this property are now referred to as Blackwell optimal. Blackwell optimality and the related concept of 1-optimality (also known as near optimality, 0-discount optimality, and bias optimality) have come to provide two of the most well studied optimality criteria for undiscounted MPDs (see, e.g., [10, 9, 13, 12, 14, 6, 7]). However, the question of which assumptions on a decision maker’s preferences lead to these criteria has not been answered in the literature.
To address this question, we consider a decision maker with preferences over . The preference relation is postulated to be reflexive and transitive, where means that is at least as good as , means that is better than ( but not ), and means that and are equally good ( and ). A policy generates a stream of expected rewards (see Eq. (3) below), where is the expected reward at time . Let denote the set of streams generated by stationary policies, that is, policies for which the action chosen at time depends only on the state at time . The principal result of this paper (Theorem 1) provides conditions on that ensure that and coincide on , where
u≿\textscBv⟺liminfβ→1−∞∑t=1βt(ut−vt)≥0 (1)
is the preference relation induced by the 1-optimality criterion. To state this result, we use the following notation: For and , we let denote . If for all and for some , we write . The long-run average
limn→∞1nn∑t=1ut (2)
of is denoted by if the limit (2) exists.
###### Theorem 1.
Let be a preference relation on with the following three properties.
A1. For all , if , then .
A2. For all , if , then .
A3. For all , if is well defined, then .
Then and coincide on .
This result is proved in [8] on a different domain (the set of streams that are either summable or eventually periodic). To prove Theorem 1, we extend the result from [8] to a larger domain (Lemma 2) and show that this domain contains (Lemma 3).
The first two assumptions in Theorem 1, A1 and A2, are standard (cf. [2, 3]). To interpret A3, which is the Compensation Principle from [8], imagine that the decision maker is faced with two different scenarios: In the first scenario, a stream of rewards is received. In the second scenario, there is a one-period postponement of , for which a compensation of is received in the first period. According to A3, the decision maker is indifferent between and if . For an axiomatic defence of this assertion, see [8, Prop. 1].
Theorem 1 tells us that if a decision maker restricts attention to stationary policies and respects A1, A2, and A3, then any stationary 1-optimal policy is (weakly) best possible with respect to his or her preferences. (The same conclusion hold for Blackwell optimal policies since such policies are 1-optimal by definition.) While restricting attention to stationary policies is often natural, it is well known that not all optimality criteria admit stationary optimal policies [5, 13, 11]. The arguments used in the proof of Theorem 1 apply to sequences that are asymptotically periodic (see Eq. (8) below). We mention without proof that as a consequence, the conclusion in Theorem 1 holds also on the set of streams generated by eventually periodic policies.
## 2. Definitions
We use Blackwell’s [4] formulation of a discrete-time MDP, with a finite set of states, a finite set of actions, and the set of all functions . Thus at each time , a system is observed to be in one of states, an action is chosen from , and a reward is received. The reward is assumed to be a function from to . The transition probability matrix and reward (column) vector that correspond to are denoted by and , respectively. So, if the system is observed to be in state and action is chosen, then a reward of is received and the system moves to with probability .
A policy is a sequence , each . The set of all policies is denoted by . A policy is stationary if for all , and eventually periodic if there exist such that for all .
The stream of expected rewards that generates, given an initial state , is the sequence defined (see [4, p. 719])
u1 =[R(f1)]s, ut =[Q(f1)…Q(ft−1)⋅R(ft)]s,t≥2. (3)
We define as the set of all that can be written (3) for some stationary and some , where is a MDP with finitely many states and finitely many actions.
## 3. Proof of Theorem 1
The proof of Theorem 1 will be completed through three lemmas. The first lemma shows that if satisfies A1A3, then and coincide on the set of pairs for which the series is Cesàro-summable and has bounded partial sums, where
u≿\textscVv⟺liminfn→∞1nn∑T=1T∑t=1(ut−vt)≥0 (4)
is the preference relation induced by Veinott’s [15] average overtaking criterion. All results presented in this paper hold with in the role of .
###### Lemma 1.
(a) The preference relation satisfies A1A3.
(b) Let be a preference relation that satisfies A1A3. For all , if the series is Cesàro-summable and has bounded partial sums, then if and only if .
###### Proof.
(a) See [8, Theorem 1]. (b) A consequence of (a) and Lemma 2 in [8]. ∎
That the conclusion in Lemma 1(b) holds with in the role of follows from that satisfies A1A3. The rest of the proof consists of identifying a superset of to which the conclusion in Lemma 1(b) extends. Lemma 2 shows that this conclusion holds on the set of that can be written
u=w+△, (5)
where is eventually periodic and the series is Cesàro-summable (the limit exists and is finite) and has bounded partial sums. Let denote the set of streams that can be written in this way.
###### Lemma 2.
A preference relation on that satisfies A1A3 is complete on and coincides with on this domain.
That is complete on means that for all , if does not hold, then .
###### Proof.
Let be a preference relation that satisfies A1A3, and let . Then . We show that if and only if . Take and such that , where for all and where is Cesàro-summable with bounded partial sums. Without loss of generality, we may assume that .
Case 1: . Then is Cesàro-summable and has bounded partial sums. This means that is Cesàro-summable and has bounded partial sums. By Lemma 1, .
Case 2: . (A similar argument applies when .) Then as . Since has bounded partial sums, . We show that . Choose and with the following properties.
(i) is eventually periodic with period .
(ii) for all and for all .
(iii) for all .
(iv) for all .
Since , (iv) follows from (i)–(ii) by taking sufficiently large. Let . By (iii), for all . This means that , is eventually periodic. Thus and hence is Cesàro-summable with bounded partial sums. Since , the Cesàro sum of is nonnegative by (iv). This means that , so by Lemma 1. Here , so by A1 and transitivity. By A2, . Since also satisfies A1A3, the same argument shows that . ∎
It remains to verify that contains . For this it is sufficient to show that every can be written
u=w+△, (6)
where is eventually periodic and goes to zero at exponential rate as . We say that is asymptotically periodic if can be written in this way.
###### Lemma 3.
If is generated by a stationary policy, then is asymptotically periodic.
###### Proof.
Let be generated by applying given an initial state , so that is the :th component of (here is the identity matrix)
Q(f)t−1⋅R(f),t≥1. (7)
We need to show that there exist and with
u=w+△, (8)
where is eventually periodic and . A well known corollary of the Perron-Frobenius theorem for nonnegative matrices says that for any stochastic matrix and , the sequence converges exponentially to a periodic orbit (see, e.g., [1].) That is, there exist , and such that for all and where
limt→∞|(Pt⋅x−y(t))s|eρt=0
for every . Thus we can take , and such that
(Q(f))t−1⋅R(f)=w(t)+e(t) (9)
for every , where for all and where each component of goes to zero faster than . If we now set , then , where is eventually periodic and . ∎
## References
• [1] Mustafa A. Akcoglu and Ulrich Krengel. Nonlinear models of diffusion on a finite space. Probability Theory and Related Fields, 76(4):441–420, 1987.
• [2] Geir B. Asheim, Claude d’Aspremont, and Kuntal Banerjee. Generalized time-invariant overtaking. Journal of Mathematical Economics, 46(4):519–533, 2010.
• [3] Kaushik Basu and Tapan Mitra. Utilitarianism for infinite utility streams: A new welfare criterion and its axiomatic characterization. Journal of Economic Theory, 133(1):350–373, 2007.
• [4] David Blackwell. Discrete dynamic programming. Annals of Mathematical Statistics, 33(2):719–726, 1962.
• [5] Barry W. Brown. On the iterative method of dynamic programming on a finite space discrete time Markov process. Ann. Math. Statist., 36(4):1279–1285, 1965.
• [6] Arie Hordijk and Alexander A. Yushkevich. Blackwell optimality. In E.A. Feinberg and A Shwartz, editors, Handbook of Markov Decision Processes, Imperial College Press Optimization Series. Springer, Boston, MA, 2002.
• [7] Hèctor Jasso-Fuentes and Onèsimo Hernàndez-Lerma. Blackwell optimality for controlled diffusion processes. Journal of Applied Probability, 46(2):372–391, 2009.
• [8] Adam Jonsson and Mark Voorneveld. The limit of discounted utilitarianism. Theoretical Economics, 2017. To appear, available at: https://econtheory.org.
• [9] J.B Lasserre. Conditions for existence of average and blackwell optimal stationary policies in denumerable markov decision processes. Journal of Mathematical Analysis and Applications, 136(2):479–489, 1988.
• [10] Steven A. Lippman. Letter to the Editor — Criterion equivalence in discrete dynamic programming. Operations Research, 17(5):920–923, 1969.
• [11] Andrzej S. Nowak and Oscar Vega-Amaya. A counterexample on overtaking optimality. Math. Methods Oper. Res., 49(3):435–439, 1999.
• [12] Alexey B. Piunovskiy. Examples in Markov decision processes, volume 2 of Imperial College Press Optimization Series. Imperial College Press, London, 2013.
• [13] Martin L. Puterman. Markov decision processes: discrete stochastic dynamic programming. Wiley Series in Probability and Mathematical Statistics. John Wiley & Sons, Inc., New York, 1994.
• [14] Dinah Rosenberg, Eilon Solan, and Nicolas Vieille. Blackwell optimality in Markov decision processes with partial observation. The Annals of Statistics, 30(4):1178–1193, 2002.
• [15] Arthur. F Veinott. On finding optimal policies in discrete dynamic programming with no discounting. Annals of Mathematical Statistics, 37(5):1284–1294, 1966.
You are adding the first comment!
How to quickly get a good reply:
• Give credit where it’s due by listing out the positive aspects of a paper before getting into which changes should be made.
• Be specific in your critique, and provide supporting evidence with appropriate references to substantiate general statements.
• Your comment should inspire ideas to flow and help the author improves the paper.
The better we are at sharing our knowledge with each other, the faster we move forward.
The feedback must be of minimum 40 characters and the title a minimum of 5 characters | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9695568084716797, "perplexity": 794.8889767944538}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593657134758.80/warc/CC-MAIN-20200712082512-20200712112512-00196.warc.gz"} |
https://gmatclub.com/forum/tough-tricky-set-of-problems-85211-20.html?kudos=1 | Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack
It is currently 25 May 2017, 02:29
### GMAT Club Daily Prep
#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
we will pick new questions that match your level based on your Timer History
Track
every week, we’ll send you an estimated GMAT score based on your performance
Practice
Pays
we will pick new questions that match your level based on your Timer History
# Events & Promotions
###### Events & Promotions in June
Open Detailed Calendar
# TOUGH & TRICKY SET Of PROBLEMS
Author Message
TAGS:
### Hide Tags
Manager
Joined: 12 Oct 2009
Posts: 115
Followers: 2
Kudos [?]: 64 [1] , given: 3
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
13 Oct 2009, 12:13
1
KUDOS
Bunuel wrote:
SOLUTION:
5. RACE:
A and B ran, at their respective constant rates, a race of 480 m. In the first heat, A gives B a head start of 48 m and beats him by 1/10th of a minute. In the second heat, A gives B a head start of 144 m and is beaten by 1/30th of a minute. What is B’s speed in m/s?
(A) 12
(B) 14
(C) 16
(D) 18
(E) 20
Let x be the speed of B.
Write the equation:
(440-48)/x (time of B for first heat) - 6 (seconds, time B lost to A first heat) = TIME OF A (in both heats A runs with constant rate, so the time for first and second heats are the same)=(440-144)/x (time of B for second heat) + 2 (seconds, time B won to A second heat)
(440-48)/x-6=(440-144)/x+2
x=12
Equation is formed with 440 whereas the question talks about 480m race. Also the equation doesnt give x=12. if I subtitute for x in equation I get 392/6 = 296/14 which is not correct
Senior Manager
Joined: 01 Mar 2009
Posts: 367
Location: PDX
Followers: 6
Kudos [?]: 91 [1] , given: 24
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
16 Oct 2009, 20:03
1
KUDOS
This is just great Bunuel - keep em coming .. Kudos
_________________
In the land of the night, the chariot of the sun is drawn by the grateful dead
Intern
Joined: 08 Mar 2009
Posts: 25
Followers: 1
Kudos [?]: 51 [1] , given: 13
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
18 Oct 2009, 11:33
1
KUDOS
thanks for the post . and 2 kudous to you for posting such gud questions
Intern
Joined: 13 Jul 2009
Posts: 20
Followers: 0
Kudos [?]: 8 [1] , given: 1
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
26 Oct 2009, 20:17
1
KUDOS
9. PROBABILITY OF INTEGER BEING DIVISIBLE BY 8:
If n is an integer from 1 to 96, what is the probability for n*(n+1)*(n+2) being divisible by 8?
A. 25%
B 50%
C 62.5%
D. 72.5%
E. 75%
Ans C 62.5%
Given, n is an integer from 1 to 96.
Case 1:
If n is even then n*(n+1)*(n+2) is divisible by 8.
reason: n is even then n is divisible by 2 and n+2 is divisible by 4. Hence the product should be divisible by 8.
ex: 2*3*4.
1 to 96 there are 48 even integers. Hence 48 possibilities divisible by 8.
If n is odd, then n*(n+1)*(n+2) is divisible by 8 when the even integer n+1 is divisible by 8.
There are 12 possible cases here. Write now multiple of 8s you will get till 96, 12 possibilities.
Add 48+12 and divide by total 96 = .625. Hence, 62.5% is correct answer.
Manager
Joined: 20 Nov 2009
Posts: 166
Followers: 8
Kudos [?]: 211 [1] , given: 64
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
02 Apr 2010, 02:36
1
KUDOS
_________________
But there’s something in me that just keeps going on. I think it has something to do with tomorrow, that there is always one, and that everything can change when it comes.
http://aimingformba.blogspot.com
Director
Joined: 25 Aug 2007
Posts: 943
WE 1: 3.5 yrs IT
WE 2: 2.5 yrs Retail chain
Followers: 77
Kudos [?]: 1329 [1] , given: 40
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
17 Apr 2010, 11:50
1
KUDOS
Bunuel wrote:
SOLUTION:
3. LEAP YEAR:
How many randomly assembled people are needed to have a better than 50% probability that at least 1 of them was born in a leap year?
A. 1
B. 2
C. 3
D. 4
E. 5
Probability of a randomly selected person NOT to be born in a leap year=3/4
Among 2 people, probability that none of them was born in a leap = 3/4*3/4=9/16. The probability at least one born in leap = 1- 9/16=7/16<1/2
So, we are looking for such n (# of people), when 1-(3/4)^n>1/2
n=3 --> 1-27/64=37/64>1/2
Thus min 3 people are needed.
Well, I have a different approach, if youhave time crunch and u want to try GUESS. As the question asked -
How many randomly assembled people are needed to have a better than 50% probability that at least 1 of them was born in a leap year
So, we need an odd number of people to select from so that the prob > 50%. This leds to choice A, C and E. 1 can't be the number. So, if we take 3 (minimum is needed) then we will have 2 people
_________________
Tricky Quant problems: http://gmatclub.com/forum/50-tricky-questions-92834.html
Important Grammer Fundamentals: http://gmatclub.com/forum/key-fundamentals-of-grammer-our-crucial-learnings-on-sc-93659.html
Intern
Joined: 11 May 2010
Posts: 1
Followers: 0
Kudos [?]: 1 [1] , given: 0
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
12 May 2010, 03:47
1
KUDOS
Bunuel wrote:
7. THE DISTANCE BETWEEN THE CIRCLE AND THE LINE:
What is the least possible distance between a point on the circle x^2 + y^2 = 1 and a point on the line y = 3/4*x - 3?
A) 1.4
B) sqrt (2)
C) 1.7
D) sqrt (3)
E) 2.0
This problem can be solved much quicker using the right triangles.
Note that line y = 3/4*x - 3, x-axis and y-axis form a 3:4:5 type triangle.
now, there are 2 quick ways to solve it from here:
1) using similar triangles - perpendicular to line y = 3/4*x - 3 creates two triangles similar to the original one , hence the length of the perpendicular can be calculated
or 2) using formula for the area of the triangle (a=1/2hieght x base) - we know area is 6 (4x3/2=6) and we know base is 5, so plug this into the formula and we get 12/5 or 2,4 for the height, which is also the length of the perpendicular we were looking for.
Hope this helps
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728
Kudos [?]: 106079 [1] , given: 11607
Re: TOUGH & TRICKY SET Of PROBLMS Question 9 [#permalink]
### Show Tags
07 Dec 2010, 03:32
1
KUDOS
Expert's post
mmcooley33 wrote:
9. PROBABILITY OF INTEGER BEING DIVISIBLE BY 8:
If n is an integer from 1 to 96 (inclusive), what is the probability for n*(n+1)*(n+2) being divisible by 8?
A. 25%
B 50%
C 62.5%
D. 72.5%
E. 75%
N=n*(n+1)*(n+2)
N is divisible by 8 in two cases:
When n is even:
No of even numbers (between 1 and 96)=48
AND
When n+1 is divisible by 8. -->n=8p-1 --> 8p-1<=96 --> p=12.3 --> 12 such nembers
Total=48+12=60
Probability=60/96=0.62
so if I were to write out n(n+1)(n+2) = n^3 + 3n^2 + 2n meaning that every even number will be divisible by 8 because every even number will have at least three 2's as factors, also taking care of the n+2 because it would be even as well, then add the 12 numbers divisible by 12 when you add 1. Is the way I am thinking correct?
Expanding is not a good idea. Below is a solution for this problem:
If an integer n is to be chosen at random from the integers 1 to 96, inclusive, what is the probability that n(n + 1)(n + 2) will be divisible by 8?
A. 1/4
B. 3/8
C. 1/2
D. 5/8
E. 3/4
$$n(n+1)(n+2)$$ is divisible by 8 in two cases:
1. When $$n$$ is even:
$$n=2k$$ --> $$n(n+1)(n+2)=2k(2k+1)(2k+2)=4k(2k+1)(k+1)$$ --> either $$k$$ or $$k+1$$ is even so 8 is a multiple of $$n(n+1)(n+2)$$.
# of even numbers between 1 and 96, inclusive is $$\frac{96-2}{2}+1=48$$ (check this: totally-basic-94862.html?hilit=last%20first%20range%20multiple)
AND
2. When $$n+1$$ is divisible by 8. --> $$n+1=8p$$ ($$p\geq{1}$$), $$n=8p-1$$ --> $$8p-1\leq{96}$$ --> $$p\leq{12.1}$$ --> 12 such numbers.
Also note that these two sets have no overlaps, as when $$n$$ and $$n+2$$ are even then $$n+1$$ is odd and when $$n+1$$ is divisible by 8 (so even) then $$n$$ and $$n+2$$ are odd.
Total=48+12=60
Probability: $$\frac{60}{96}=\frac{5}{8}=62.5%$$
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728
Kudos [?]: 106079 [1] , given: 11607
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
21 Feb 2011, 09:35
1
KUDOS
Expert's post
it is time of B - time of A = 6
changed the order ..
thnx
Check some other rate problems here: search.php?search_id=tag&tag_id=64
Hope it helps.
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728
Kudos [?]: 106079 [1] , given: 11607
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
03 Apr 2012, 10:32
1
KUDOS
Expert's post
theamwan wrote:
Bunuel wrote:
That's not correct out of 4 years 1 is leap, so the probability of a randomly selected person NOT to be born in a leap year is 3/4.
But the question doesn't say that it's a set of 4 consecutive years. What if the years chosen are 2011, 2010, 2009, 2007?
IMO, a person's birth year to fall on a leap year should be a binary value - Y or N, hence a 50% probability.
Again that's not correct. Let me ask you a question: what is the probability that a person in born on Monday? Is it 1/2? No, it's 1/7.
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728
Kudos [?]: 106079 [1] , given: 11607
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
30 Jun 2012, 04:17
1
KUDOS
Expert's post
dianamao wrote:
Bunuel wrote:
SOLUTION:
6. PROBABILITY OF DRAWING:
A bag contains 3 red, 4 black and 2 white balls. What is the probability of drawing a red and a white ball in two successive draws, each ball being put back after it is drawn?
(A) 2/27
(B) 1/9
(C) 1/3
(D) 4/27
(E) 2/9
This is with replacement case (and was solved incorrectly by some of you):
$$P=2*\frac{3}{9}*\frac{2}{9}=\frac{4}{27}$$
We are multiplying by 2 as there are two possible wining scenarios RW and WR.
The question says that red and white balls are selected in two Successive draws. Doesn't this imply that white is selected AFTER red? Thus no need for x2?
Thanks,
Diana
No, in that case we would be asked "what is the the probability of the first ball being red and the second ball being white?"
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728
Kudos [?]: 106079 [1] , given: 11607
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
21 Dec 2012, 04:40
1
KUDOS
Expert's post
Archit143 wrote:
I think i made mistake since 6 can be also a probable number but is not a multiple of 4..............Bunuel can u pls help me solve this one using multiple principle
If an integer n is to be chosen at random from the integers 1 to 96, inclusive, what is the probability that n(n + 1)(n + 2) will be divisible by 8?
A. 25%
B. 50%
C. 62.5%
D. 72.5%
E. 75%
$$n(n + 1)(n + 2)$$ is divisible by 8 in two cases:
A. $$n=even$$, in this case $$n+2=even$$ too and as $$n$$ and $$n+2$$ are consecutive even integers one of them is also divisible by 4, so their product is divisible by 2*4=8;
B. $$n+1$$ is itself divisible by 8;
(Notice that these two sets have no overlaps, as when $$n$$ and $$n+2$$ are even then $$n+1$$ is odd and when $$n+1$$ is divisible by 8 (so even) then $$n$$ and $$n+2$$ are odd.)
Now, in EACH following groups of 8 numbers: {1-8}, {9-16}, {17-24}, ..., {89-96} there are EXACTLY 5 numbers satisfying the above two condition for n, for example in {1, 2, 3, 4, 5, 6, 7, 8} n can be: 2, 4, 6, 8 (n=even), or 7 (n+1 is divisible by 8). So, the overall probability is 5/8=0.625.
Similar question: divisible-by-12-probability-121561.html
Hope it helps.
_________________
Manager
Joined: 12 Oct 2009
Posts: 115
Followers: 2
Kudos [?]: 64 [0], given: 3
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
13 Oct 2009, 13:00
Bunuel wrote:
asterixmatrix wrote:
Bunuel wrote:
SOLUTION:
5. RACE:
A and B ran, at their respective constant rates, a race of 480 m. In the first heat, A gives B a head start of 48 m and beats him by 1/10th of a minute. In the second heat, A gives B a head start of 144 m and is beaten by 1/30th of a minute. What is B’s speed in m/s?
(A) 12
(B) 14
(C) 16
(D) 18
(E) 20
Let x be the speed of B.
Write the equation:
(440-48)/x (time of B for first heat) - 6 (seconds, time B lost to A first heat) = TIME OF A (in both heats A runs with constant rate, so the time for first and second heats are the same)=(440-144)/x (time of B for second heat) + 2 (seconds, time B won to A second heat)
(440-48)/x-6=(440-144)/x+2
x=12
Equation is formed with 440 whereas the question talks about 480m race. Also the equation doesnt give x=12. if I subtitute for x in equation I get 392/6 = 296/14 which is not correct
First of all thanks for pointing out the typo. Edited the post above. Second it's funny but the equation with typo also gives the correct answer x=12:
392/x-6=296/x+2 --> 96/x=8 x=12
432/x-6=336/x+2 --> 96/x=8 x=12
since we subtract from a common value thats y we get the ans as 12 even with incorrect value
Asterix
Maths was better with 1 and 0s
Manager
Joined: 28 Jul 2009
Posts: 123
Followers: 2
Kudos [?]: 26 [0], given: 12
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
16 Oct 2009, 09:17
Thanks ..
Keep them coming .. i enjoyed a lot solving them .
GMAT quant is getting tougher ... there questions will surely train us . thx ..
Intern
Joined: 13 Oct 2009
Posts: 8
Followers: 0
Kudos [?]: 4 [0], given: 0
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
19 Oct 2009, 04:42
jax91 wrote:
1.) (E) 159
4.) AB + CD = AAA
adding 2 2 digit numbers is giving a 3 digit number. So hunderds digit of the 3 digit number has to be 1
so it becomes 1B + CD = 111
B cannot be 1, CD cannot be 99 (they are distinct)
so CD can take any value from 98 to 92.
So (E) Cannot be determined
That not true... the question is on C and not CD --> answer is 9.
Senior Manager
Affiliations: PMP
Joined: 13 Oct 2009
Posts: 305
Followers: 4
Kudos [?]: 168 [0], given: 37
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
26 Oct 2009, 20:05
Awesome questions and explanations. I could solve 80%, dist from circle to line was the best and I had no clue...
_________________
Thanks, Sri
-------------------------------
keep uppp...ing the tempo...
Press +1 Kudos, if you think my post gave u a tiny tip
Intern
Joined: 29 Sep 2009
Posts: 1
Followers: 0
Kudos [?]: 0 [0], given: 0
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
31 Oct 2009, 06:43
Bunuel wrote:
SOLUTION:
1. THE SUM OF EVEN INTEGERS:
The sum of the even numbers between 1 and k is 79*80, where k is an odd number, then k=?
(A) 79
(B) 80
(C) 81
(D) 157
(E) 159
The solution given in the file was 79, which is not correct. Also the problem was solved with AP formula thus was long and used the theory rarely tested in GMAT. Here is my solution and my notes about AP. Some may be useful:
The number of terms in this set would be: n=(k-1)/2 (as k is odd)
Last term: k-1
Average would be first term+last term/2=(2+k-1)/2=(k+1)/2
Also average: sum/number of terms=79*80/((k-1)/2)=158*80/(k-1)
(k+1)/2=158*80/(k-1) --> (k-1)(k+1)=158*160 --> k=159
How is n = (k-1)/2??
If the last term is K, and the 1st term is 1, the no. of terms should be k-1+1
Hence, here the no. of terms should be =>(k-1+1)/2 => k/2 since there should be half as many even numbers...
Am I missing something?
Intern
Joined: 18 Dec 2009
Posts: 13
Followers: 0
Kudos [?]: 8 [0], given: 4
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
18 Dec 2009, 11:53
A very good (ofcourse tough and tricky) set of problems. But when i was prcticing the tests from book that time i felt they are quite easier. Are these the actual type of questions that come in GMAT?
Intern
Status: Life is all about experience.
Joined: 06 Nov 2009
Posts: 6
Location: Japan
Concentration: Technology, Entrepreneurship
GMAT 1: 710 Q50 V38
GPA: 3.34
Followers: 0
Kudos [?]: 10 [0], given: 0
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
22 Dec 2009, 21:28
9. PROBABILITY OF INTEGER BEING DIVISIBLE BY 8:
If n is an integer from 1 to 96, what is the probability for n*(n+1)*(n+2) being divisible by 8?
A. 25%
B 50%
C 62.5%
D. 72.5%
E. 75%
Ans C 62.5%
--------------------------------------------------------------
I solve it in an opposite side of view.
How about n is odd and n,n+2 are both odds, which means only if n+1 is indivisible by 8 can satisfy the product of n*(n+1)*(n+2) is indivisible.
Let's take a look at n+1 which is even.
There are 48 even integers from 1 to 96. 96/2 = 48, and among these 48 even integers, 96/8=12 of them are divisible by 8. So 48-12=36 even integers are indivisible. 1 - 36/96 = 0.625
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728
Kudos [?]: 106079 [0], given: 11607
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink]
### Show Tags
23 Dec 2009, 15:35
Vyacheslav wrote:
7. THE DISTANCE BETWEEN THE CIRCLE AND THE LINE:
What is the least possible distance between a point on the circle x^2 + y^2 = 1 and a point on the line y = 3/4*x - 3?
A) 1.4
B) sqrt (2)
C) 1.7
D) sqrt (3)
E) 2.0
I find useful to roughly draw such questions. You can instantly recognize that line y=3/4*x-3 and axises form a right triangle with sides 3 and 4, on Y-axis and X-axis respectively. The hypotenuse lies on the line y=3/4*x-3 and equals 5 (Pythagorean Triple). The closest distance from any point to line is perpendicular from that point to line. Perpendicular to the hypotenuse (from origin in this case) will always divide the triangle into two triangles with the same properties as the original triangle. So, lets perpendicular will $$x$$, then
$$\frac{x}{3}=\frac{4}{5}$$ and $$x=3*\frac{4}{5}=\frac{12}{5}=2,4$$
To find distance from point on circle to line we should substract lenth of radius from lenth of perpendicular: 2,4-1=1,4
Unfortunately, I cannot attach illustration. But if you draw this problem (even roughly), you will find it really easy to solve.
Excellent! +1.
For those who don't know the distance formula (which is in fact very rarely tested) this is the easiest and most elegant solution.
_________________
Re: TOUGH & TRICKY SET Of PROBLMS [#permalink] 23 Dec 2009, 15:35
Go to page Previous 1 2 3 4 5 6 7 8 9 Next [ 166 posts ]
Similar topics Replies Last post
Similar
Topics:
Tough and tricky 6: Probability of drawing 5 11 Feb 2011, 04:43
9 Tough and tricky 4: addition problem 9 26 Sep 2013, 06:17
3 Tough and tricky 3: leap year 6 30 Oct 2016, 10:39
1 Tough and tricky 2: 4 02 Dec 2012, 23:07
7 Tough and tricky: The sum of the even numbers. 7 17 May 2015, 22:08
Display posts from previous: Sort by | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6637550592422485, "perplexity": 2250.362973216653}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-22/segments/1495463608058.13/warc/CC-MAIN-20170525083009-20170525103009-00473.warc.gz"} |
http://www.sciforums.com/threads/gravity-never-zero.111586/page-36 | # Gravity never zero
Discussion in 'Astronomy, Exobiology, & Cosmology' started by Ivan, Dec 18, 2011.
Thread Status:
Not open for further replies.
1. ### OnlyMeValued Senior Member
Messages:
3,747
Refer back to "The Concept of Mass" previously linked.., there is no "relativistic mass" there is just mass. Sometimes referred to as invariant mass, inertial mass, gravitational mass or rest mass. They are all the same thing and relativistic mass is a confusing and misleading description for the TOTAL energy, of an invariant mass plus any kinetic energy associated with its velocity.
While E is generally used to denote total energy, the total energy it refers to is defined by the context it is used. In the equation E = mc^2, it referrs only to the total energy associated with a specific invariant mass. It does not include any energy associated with acceleration or velocity.
2. ### Google AdSenseGuest Advertisement
to hide all adverts.
3. ### Robittybob1BannedBanned
Messages:
4,199
But that was the thing I was leading too, you can't weigh an electron once it is motion (bound). I was thinking we might have to say it has rest mass plus Energy = hV (Planck's constant times electron wave frequecy).
4. ### Google AdSenseGuest Advertisement
to hide all adverts.
5. ### EmilValued Senior Member
Messages:
2,789
Fireflies lose weight when emits light?
6. ### Google AdSenseGuest Advertisement
to hide all adverts.
7. ### OnlyMeValued Senior Member
Messages:
3,747
No, E refers to the TOTAL ENERGY of the invariant mass m.
I do not completely understand what you are saying here.., however, "I think" you are confusing the equation $E = mc^2$, with $E = \frac{mc^2}{\sqrt{1-v^2/c^2}}$. These are two different equations and E represents a different total energy in each. E in the first equation is defined above. In the second equation E represents the total energy associated with both an invariant mass and any energy associated with its velocity. It is a misinterpretation or perhaps old and misleading interpretation of this second formula that often leads these discussions "down the rabbit hole".
As others have tried to point out there are other ways to mathematically describe both, but they involve an understanding of math that I think is beyond the discussion here.
8. ### OnlyMeValued Senior Member
Messages:
3,747
That was really good! You got me laughing and almost choking.
Theoretically, yes. But I don't believe we have scales than can measure the loss.
9. ### Robittybob1BannedBanned
Messages:
4,199
Yes but it might gain mass when it flies at the speed of light.
10. ### RealityCheckBannedBanned
Messages:
800
.
Hi guys.
I'm trying to review the K-capture process (where one electron from the K-shell is absorbed by a proton in a nucleus and an electron from the L-shell drops down to replace the absorbed K-shell electron, emitting a photon as the replacement electron drops from the L to the K shell).
The questions which I would like to have clarified are:
- does the proton-to-neutron conversion of the electron-capturing proton increase the mass of that proton perfectlt commensurate with the mass of that electron when in its K-shell bound state?...or is the mass/energy of the newly formed neutron different by some amount (either gained or lost somehow when being captured)?
- is there any radiation/particle emitted when that capture takes place and the K-shell electron drops from a higher energy bound state (in erstwhile K-shell state) to a lower energy bound state (as part of, or otherwise now contributing to the creation of a neutron where before there was only a proton)?
- does the mass of the erstwhile L-shell electron change (decrease) perfectly commensurate with the (X-ray?) photon energy emitted when it drops from the L to the K shell?...and if so, is the now-departing X-ray just a mass which has attained lightspeed, and so being effectively 'massless' purely by dint of having attained that speed and tus all its mass is 'moving in the one direction' rather than being 'self-involved' into some sort of self-interfering state which makes its energy/mass content movement trying to go in many directions at one and so making it more 'ponderous' when part of the electron and now less ponderous because of its single-direction motion as an X-ray photon whose total energy is going in one common direction?
I am much obliged for all your inputs and to the OP/thread author. Kudos.
Your discussion is very interesting on many levels. And if anyone here can cast any light on my questions in the context of this discussion so far, I would be very grateful for any inputs related to the aspects I mentioned.
Cheers!
.
Last edited: Mar 25, 2012
11. ### Robittybob1BannedBanned
Messages:
4,199
Rambling thoughts on the issue:
When an electron is ionized it will fly off its source molcule as a high speed electron. Which then can be slowed down probably by a magnetic field say so the excess energy over and above the electron's Rest Mass is removed.
I find it rather fascinating that from the ubiquitous electron as it reunits with the ionized atoms it can gice off photons of the exact amount to drop down through a cascade of electron energy levels. One would think there could be a reversal of the energy release process and the energy capture when the electron absorbs an electron and jumps up a level. The wave of the light is blended in with the wave path of the electron (just my primitive picture). I wonder if the momentum of the photon reflects the molecular vibratory momentum of motion at the time of release??? The direction it was going determines the direction of the photon ( How does a laser work?)
12. ### hansdaValued Senior Member
Messages:
1,641
What is the TOTAL ENERGY (TE) of the invariant mass (M) ?
TOTAL ENERGY (TE) = POTENTIAL ENERGY (PE) + KINETIC ENERGY(KE) .
This TOTAL ENERGY (TE) of a invariant mass (M) is constant . PE and KE changes accordingly so that TOTAL ENERGY(TE) remains constant .
In Einstein's Equation E = MC^2 ; the mass M is diminished and its PE and KE gets converted into LIGHT ENERGY . Here TOTAL ENERGY (TE) of mass (M) is converted into LIGHT ENERGY . So, this E also can be referred as LIGHT ENERGY . Here M can be either mass of electron , neutron or proton but NOT photon .
If you refer Einstein's paper (for which you already supplied the link earlier(thank you for that link)) , Einstein used two co-ordinate system at a relative velocity . He also considered Lorentz Transformation of Energy in these two co-ordinate system to prove his Equation . These two E's as you mentioned above corresponds to the energy(E) in the two co-ordinate system . In his paper he used the terms L and L* to denote these two energies instead of E's .
Einstein in his paper used simple math of Lorentz Transformation , in two co-ordinate system to prove his famous equation .
His last mathematical equation in his paper is K0 − K1 = (1/2) (L/c^2)v^2 .
where H0 − E0 = K0 + C ; H1 − E1 = K1 + C .
The following is quote from Einstein's paper to understand H , E and K .
[ NOTE : In the above quote I deleted , modified some mathematical expressions for ease of copy-paste from your link of Einstein's paper .]
From the equation K0 − K1 = (1/2) (L/c^2)v^2 ; he concluded that
M = L/c^2 or L = Mc^2 .
13. ### hansdaValued Senior Member
Messages:
1,641
Is the Sun or other stars loosing mass because they emit light or photon ?
Is our Earth or other planets gaining mass because they absorb light ?
What I think is that , particle photon carries Light-Energy and not Kinetic-Energy . So , absorption of a photon may increase energy-content but may not increase mass-content or inertia-content .
14. ### Robittybob1BannedBanned
Messages:
4,199
"Is the Sun or other stars loosing mass because they emit light or photon ?
" - Yes
"Is our Earth or other planets gaining mass because they absorb light" - If that was the case it would be called "Heavy " not "Light". No. because it is re-radiated away again.
Read the posts in the CO2 absorbing photon thread discussing this.
15. ### hansdaValued Senior Member
Messages:
1,641
Do you mean to say if an electron absorbs a photon ; the mass of the electron will increase ?
16. ### Robittybob1BannedBanned
Messages:
4,199
Now that they talk of the electron cloud the whole discussion gets blurry too. So I don't know but I was thinking it must for when you think of the electron as a particle it slows down after gaining energy and the only way I think that can happen is that the mass is raised. I was going to look into this as that Photon absorption thread progresses, so I really don't know at this stage.
What is your take on this? What does the internet say? Type this question as a google search and see what sort of answers you get.
Does electron gain mass after absorbing photon?
17. ### hansdaValued Senior Member
Messages:
1,641
I think we have already discussed this issue earlier . If an electron slows down after gaining energy(kinetic energy) ; this may be a case of frame-dragging effect , which slows down the sub-atomic particle . See post number #388 .
Internet says NO . So, mass of an electron does not increase after absorbing photon , only its kinetic energy and momentum increases .
See the following sites .
1. http://astronomyonline.org/Science/Atoms.asp
2. http://wiki.answers.com/Q/Does_photon_absorption_cause_an_electron_to_gain_mass
Last edited: Mar 30, 2012
18. ### OnlyMeValued Senior Member
Messages:
3,747
Hansda, read the about me for the first link. It is a blog by an author who joined the military out of high school and claims his job was as an eye specialist. Not that this in itself limits his credibility, but he would likely not be able to publish even in arXiv.
The second reference seems focused more toward practical applications, chemistry etc. And the answers author is not, at least readily identified. That makes it difficult to understand the contex of the answer.
While there is some debate whether the electron itself gains mass with absorption, or the added mass is some function of the atom as a whole system is debatable, an increase of mass is the underlying principle behind the equation E = mc^2.
19. ### hansdaValued Senior Member
Messages:
1,641
May be you are right . But can you show any reference , which says 'mass of an electron increases after absorbing photon' .
This is a wiki site for wiki answers . So, this can be accepted as 'right' .
I think you are confusing with increase of relativistic-mass which slows down an electron .
It is not relativistic-mass but the effect of frame-dragging which slows down an electron .
With the absorption of photon , electron's kinetic energy and momentum increases . This increased momentum can cause frame-dragging , which in turn may slow down electron .
Last edited: Mar 30, 2012
20. ### OnlyMeValued Senior Member
Messages:
3,747
I think I have posted both of these references earlier, but once again...
DOES THE INERTIA OF A BODY DEPEND UPON ITS ENERGY-CONTENT? this is Einstein's 1905 paper that introduces the equation E = mc^2 and its association with photon emission/absorption.
The Concept of Mass
Thus a massless photon may "transfer" nonvanishing mass. In absorbing a massless photon, ...
In the above reference, Lev Okun discusses the whole relativistic mass issue. Though when I have provided this link in the past I thought it was relatively clear and simple, I seem to be mistaken on that. You will have to think some of it through, since Okun presents both the historical view and context and the contemporay perspective. The specific quote does speak to a photon transferring mass, but not in the exact same context as we have been discussing. It still involves the electron but he describes it in the context of an object.., a cylinder....
WiKi is not always the best source of up to date information. It is both a good resource and at the same time, sometimes includes outdated concepts without discussing the contemporary view of an issue. This is the case for relativistic mass which does not exist. Mass is mass is mass. It is invariant. A particles velocity in at least the macroscopic view does not change its mass.
21. ### hansdaValued Senior Member
Messages:
1,641
Followings are three quotes from Einstein's paper .
1.
What do you understand by the term 'energy-content' ?
Is it radiation-energy ? Total-Energy ? Potential-Energy ? Kinetic-Energy ?
2.
Radium salts may loose mass with emission of radiation but do they also gain mass with absorption of radiation ? Is it experimentally proven ?
3.
Here Einstein says , " If the theory corresponds to facts , ..." . He explains his theory only with emission but not with absorption . His theory is proven for emission of energy . Is his theory also proven for absorption of energy ?
I could not access Lev Okun's paper .
Last edited: Mar 30, 2012
22. ### OnlyMeValued Senior Member
Messages:
3,747
L as used by Einstein in that paper represents the total energy associated with a specific mass, excluding any kinetic energy associated with its motion in space.
Where the radium salts issue was raised, Eimstein at the time appears to have had no knowledge that radiation associated with radium is alpha radiation, not photons. Alpha particles have mass. Remember this was 1905.
I believe Einstein actually says that mass is transferred as energy in the emission and absorption.., of energy, where the energy referred to is the photon... But I have not gone back and checked the actual wording. Positing on a device with limited memory I often lose connection with SciForums when switching to my PDF library.
What was the issue with your access to Okun's paper? Was it an issue related to a bad link or translation?
23. ### hansdaValued Senior Member
Messages:
1,641
What do you mean by " total energy " ?
Is it mechanical energy ( potential or kinetic ) ? ... Light energy ? ... Chemical energy ? ... Nuclear energy ? or some other form of energy ? Consider the fact that there are only eight forms of energy .
What do you mean by specific mass ?
Is it " rest mass " ? ... simply mass or something else ?
Einstein mentioned radium salts as an example in his paper .
Please go through Einstein's paper as you provided the link . Einstein used the word "IF" to prove his claim that , mass increases with absorbing radiation energy .
So, Einstein's this paper is not conclusive proof that , mass of an electron increases with absorbing a photon .
Now I am able to get Okun's paper .
Thread Status:
Not open for further replies. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9219520688056946, "perplexity": 1204.5549470207575}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-27/segments/1435375102712.76/warc/CC-MAIN-20150627031822-00159-ip-10-179-60-89.ec2.internal.warc.gz"} |
https://worldwidescience.org/topicpages/s/superimposable+3d+arrangements.html | #### Sample records for superimposable 3d arrangements
1. Superimposing of virtual graphics and real image based on 3D CAD information
Institute of Scientific and Technical Information of China (English)
2000-01-01
Proposes methods of transforming 3D CAD models into 2D graphics and recognizing 3D objects by features and superimposing VE built in computer onto real image taken by a CCD camera, and presents computer simulation results.
2. Does spatial arrangement of 3D plants affect light transmission and extinction coefficient within maize crops?
Science.gov (United States)
Row spacing effects on light interception and extinction coefficient have been inconsistent for maize (Zea mays L.) when calculated with field measurements. To avoid inconsistencies due to variable light conditions and variable leaf canopies, we used a model to describe three-dimensional (3D) shoot ...
3. Trabecular network arrangement within the human patella: how osteoarthritis remodels the 3D trabecular structure
Science.gov (United States)
Hoechel, Sebastian; Deyhle, Hans; Toranelli, Mireille; Müller-Gerbl, Magdalena
2016-10-01
Following the principles of "morphology reveals biomechanics", the anatomical structure of the cartilage-osseous interface and the supporting trabecular network show defined adaptation in their architectural properties to physiological loading. In case of a faulty relationship, the ability to support the load diminishes and the onset of osteoarthritis (OA) may arise and disturb the balanced formation and resorption processes. To describe and quantify the changes occurring, 10 human OA patellae were analysed concerning the architectural parameters of the trabecular network within the first five mms by the evaluation of 3Dmicro-CT datasets. The analysed OA-samples showed a strong irregularity for all trabecular parameters across the trabecular network, no regularity in parameter distribution was found. In general, we saw a decrease of material in the OA population as BV/TV, BS/TV, Tb.N and Tb.Th were decreased and the spacing increased. The development into depth showed a logarithmic dependency, which revealed the greatest difference for all parameters within the first mm in comparison to the physiologic samples. The differences decreased towards the 5th mm. The interpretation of the mathematic dependency leads to the conclusion that the main impact of OA is beneath the subchondral bone plate (SBP) and lessens with depth. Next to the clear difference in material, the architectural arrangement is more rod-like and isotropic just beneath the SBP in comparison to the plate-like and more anisotropic physiological arrangement.
4. Optical low-cost and portable arrangement for full field 3D displacement measurement using a single camera
Science.gov (United States)
López-Alba, E.; Felipe-Sesé, L.; Schmeer, S.; Díaz, F. A.
2016-11-01
In the current paper, an optical low-cost system for 3D displacement measurement based on a single camera and 3D digital image correlation is presented. The conventional 3D-DIC set-up based on a two-synchronized-cameras system is compared with a proposed pseudo-stereo portable system that employs a mirror system integrated in a device for a straightforward application achieving a novel handle and flexible device for its use in many scenarios. The proposed optical system splits the image by the camera into two stereo images of the object. In order to validate this new approach and quantify its uncertainty compared to traditional 3D-DIC systems, solid rigid in and out-of-plane displacements experiments have been performed and analyzed. The differences between both systems have been studied employing an image decomposition technique which performs a full image comparison. Therefore, results of all field of view are compared with those using a stereoscopy system and 3D-DIC, discussing the accurate results obtained with the proposed device not having influence any distortion or aberration produced by the mirrors. Finally, the adaptability of the proposed system and its accuracy has been tested performing quasi-static and dynamic experiments using a silicon specimen under high deformation. Results have been compared and validated with those obtained from a conventional stereoscopy system showing an excellent level of agreement.
5. Correlation between spatial (3D) structure of pea and bean thylakoid membranes and arrangement of chlorophyll-protein complexes
NARCIS (Netherlands)
Rumak, Izabela; Mazur, Radoslaw; Gieczewska, Katarzyna; Koziol-Lipinska, Joanna; Kierdaszuk, Borys; Michalski, Wojtek P.; Shiell, Brian J.; Venema, Jan Henk; Vredenberg, Wim J.; Mostowska, Agnieszka; Garstka, Maciej
2012-01-01
Background: The thylakoid system in plant chloroplasts is organized into two distinct domains: grana arranged in stacks of appressed membranes and non-appressed membranes consisting of stroma thylakoids and margins of granal stacks. It is argued that the reason for the development of appressed membr
6. An image-based approach to the reconstruction of ancient architectures by extracting and arranging 3D spatial components
Institute of Scientific and Technical Information of China (English)
Divya Udayan J; HyungSeok KIM; Jee-In KIM
2015-01-01
The objective of this research is the rapid reconstruction of ancient buildings of historical importance using a single image. The key idea of our approach is to reduce the infi nite solutions that might otherwise arise when recovering a 3D geometry from 2D photographs. The main outcome of our research shows that the proposed methodology can be used to reconstruct ancient monuments for use as proxies for digital effects in applications such as tourism, games, and entertainment, which do not require very accurate modeling. In this article, we consider the reconstruction of ancient Mughal architecture including the Taj Mahal. We propose a modeling pipeline that makes an easy reconstruction possible using a single photograph taken from a single view, without the need to create complex point clouds from multiple images or the use of laser scanners. First, an initial model is automatically reconstructed using locally fi tted planar primitives along with their boundary polygons and the adjacency relation among parts of the polygons. This approach is faster and more accurate than creating a model from scratch because the initial reconstruction phase provides a set of structural information together with the adjacency relation, which makes it possible to estimate the approximate depth of the entire structural monument. Next, we use manual extrapolation and editing techniques with modeling software to assemble and adjust different 3D components of the model. Thus, this research opens up the opportunity for the present generation to experience remote sites of architectural and cultural importance through virtual worlds and real-time mobile applications. Variations of a recreated 3D monument to represent an amalgam of various cultures are targeted for future work.
7. Characterization of an experimental arrangement to measure position of particles in 3D with a high accuracy
Science.gov (United States)
Martínez González, A.; Guerrero Viramontes, J. A.; Moreno Hernández, D.
2011-09-01
Single particle position calculation in three dimensions (3D) with high accuracy is the very important in several branches of science. On the other hand, the use of in-line holography to study very small objects in a dynamic volume is a technique of importance for scientists and engineers across a variety of disciplines for obtaining information about size, shape, trajectory and velocity of small objects such as dust particles. However, in general for in-line holography, accurate determination of the object's position in the optical axis direction is difficult. In order to overcome this shortcoming, we proposed to use in-line holography set up to record particle images in two orthogonal forward configurations. In this study, we avoid digital holography reconstruction to calculate particle position. To determine particle position, the proposed method is based on the calculation of the size and position of the central spot size (CSS) of a particle diffraction image. The size of the CSS is calculated by using the Continuous Wavelet Transform (CWT) and Continuous Hough Transforms (CHT), an then the size of the CSS is related to a calibration curve calculated experimentally in order to determine the "z" particle position and centroid of the CSS render the "x-y" position of a particle image. The procedure proposed in this work to determine the 3D particle position is so simple since it avoids a complicated experimental set-up and several computational steps in order to obtain the 3D position of the particles. Our approach offers the following advantages: First, the mathematical accuracy, light illumination as well as particle and medium refractive indexes are used during the analysis. Second, it is not required to resolve the size of particle since we calculate only the size of CSS of a diffraction particle image pattern.
8. Self-arrangement of nanoparticles toward crystalline metal oxides with high surface areas and tunable 3D mesopores
Science.gov (United States)
Lee, Hyung Ik; Lee, Yoon Yun; Kang, Dong-Uk; Lee, Kirim; Kwon, Young-Uk; Kim, Ji Man
2016-02-01
We demonstrate a new design concept where the interaction between silica nanoparticles (about 1.5 nm in diameter) with titania nanoparticles (anatase, about 4 nm or 6 nm in diameter) guides a successful formation of mesoporous titania with crystalline walls and controllable porosity. At an appropriate solution pH (~1.5, depending on the deprotonation tendencies of two types of nanoparticles), the smaller silica nanoparticles, which attach to the surface of the larger titania nanoparticles and provide a portion of inactive surface and reactive surface of titania nanoparticles, dictate the direction and the degree of condensation of the titania nanoparticles, resulting in a porous 3D framework. Further crystallization by a hydrothermal treatment and subsequent removal of silica nanoparticles result in a mesoporous titania with highly crystalline walls and tunable mesopore sizes. A simple control of the Si/Ti ratio verified the versatility of the present method through the successful control of mean pore diameter in the range of 2-35 nm and specific surface area in the ranges of 180-250 m2 g-1. The present synthesis method is successfully extended to other metal oxides, their mixed oxides and analogues with different particle sizes, regarding as a general method for mesoporous metal (or mixed metal) oxides.
9. 3D Computation of Hydrogen-Fueled Combustion around Turbine Blade-Effect of Arrangement of Injector Holes -
Institute of Scientific and Technical Information of China (English)
Makoto YAMAMOTO; Junichi IKEDA; Kazuaki INABA
2006-01-01
Recently, a number of environmental problems caused from fossil fuel combustion have been focused on. In addition, with the eventual depletion of fossil energy resources, hydrogen gas is expected to be an alternative energy resource in the near future. It is characterized by high energy per unit weight, high reaction rate, wide range of flammability and the low emission property. On the other hand, many researches have been underway in several countries to improve a propulsion system for an advanced aircraft. The system is required to have higher power, lighter weight and lower emissions than existing ones. In such a future propulsion system, hydrogen gas would be one of the promising fuels for realizing the requirements. Considering these backgrounds, our group has proposed a new cycle concept for hydrogen-fueled aircraft propulsion system. In the present study, we perform 3dimensional computations of turbulent flow fields with hydrogen-fueled combustion around a turbine blade. The main objective is to clarify the influence of arrangement of hydrogen injector holes. Changing the chordwise and spanwise spacings of the holes, the 3 dimensional nature of the flow and thermal fields is numerically studied.
10. [Superimposed lichen planus pigmentosus].
Science.gov (United States)
Monteagudo, Benigno; Suarez-Amor, Óscar; Cabanillas, Miguel; de Las Heras, Cristina; Álvarez, Juan Carlos
2014-05-16
Lichen planus pigmentosus is an uncommon variant of lichen planus that is characterized by the insidious onset of dark brown macules in sun-exposed areas and flexural folds. Superimposed linear lichen planus is an exceedingly rare disorder, but it has been found in both lichen planopilaris and lichen planus types. A 39-year-old woman is presented showing a segmental and linear lichen planus associated with non-segmental lesions meeting all criteria for the diagnosis of superimposed linear planus pigmentosus. The segmental lesions were always more pronounced.
11. Recent improvement of a FIB-SEM serial-sectioning method for precise 3D image reconstruction - application of the orthogonally-arranged FIB-SEM.
Science.gov (United States)
Hara, Toru
2014-11-01
IntroductionWe installed the first "orthogonally-arranged" FIB-SEM in 2011. The most characteristic point of this instrument is that the FIB and SEM columns are perpendicularly mounted; this is specially designed to obtain a serial-sectioning dataset more accurately and precisely with higher contrast and higher spatial resolution compare to other current FIB-SEMs [1]. Since the installation in 2011, we have developed the hardware and methodology of the serial-sectioning based on this orthogonal FIB-SEM. In order to develop this technique, we have widely opened this instrument to every researcher of all fields. In the presentation, I would like to introduce some of application results that are obtained by users of this instrument. The characteristic points of the orthogonal systemFigure 1 shows a difference between the standard and the orthogonal FIB-SEM systems: In the standard system, shown in Fig.1(a), optical axes of a FIB and a SEM crosses around 60deg., while in the orthogonal system (Fig.1(b)), they are perpendicular to each other. The standard arrangement (a) is certainly suitable for TEM lamellae preparation etc. because the FIB and the SEM can see the same position simultaneously. However, for a serial-sectioning, it is not to say the best arrangement. One of the reasons is that the sliced plane by the FIB is not perpendicular to the electron beam so that the background contrast is not uniform and observed plane is distorted. On the other hand, in case of the orthogonally-arranged system,(b), these problems are resolved. In addition, spatial resolution can keep high enough even in a low accelerating voltage (e.g. 500V) because a working distance is set very small, 2mm. From these special design, we can obtain the serial-sectioning dataset from rather wide area (∼100um) with high spatial resolution (Max. 2×2×2nm). As this system has many kinds of detectors: SE, ET, Backscatter Electron(Energy-selective), EDS, EBSD, STEM(BF&ADF), with Ar+ ion-gun and a
12. Bent Solenoids with Superimposed Dipole Fields
Energy Technology Data Exchange (ETDEWEB)
Meinke, Rainer, B.; Goodzeit, Carl, L.
2000-03-21
A conceptual design and manufacturing technique were developed for a superconducting bent solenoid magnet with a superimposed dipole field that would be used as a dispersion device in the cooling channel of a future Muon Collider. The considered bent solenoid is equivalent to a 180° section of a toroid with a major radius of ~610 mm and a coil aperture of ~416 mm. The required field components of this magnet are 4 tesla for the solenoid field and 1 tesla for the superimposed dipole field. A magnet of this size and shape, operating at these field levels, has to sustain large Lorentz forces resulting in a maximum magnetic pressure of about 2,000 psi. A flexible round mini-cable with 37 strands of Cu-NbTi was selected as the superconductor. Detailed magnetic analysis showed that it is possible to obtain the required superimposed dipole field by tilting the winding planes of the solenoid by ~25°. A complete structural analysis of the coil support system and the helium containment vessel under thermal, pressure, and Lorentz force loads was carried out using 3D finite element models of the structures. The main technical issues were studied and solutions were worked out so that a highly reliable magnet of this type can be produced at an affordable cost.
13. Research on Superimposed Metallogenic System
Institute of Scientific and Technical Information of China (English)
Zhai Yusheng; Wang Jianping; Deng Jun; Peng Runmin
2004-01-01
As located in the junction of three tectonic plates (the Eurasian plate, the Indian plate and the west Pacific plate), the China continent shows complex regional metallogenic features due to tectonic evolution of "micro-plates, polycycle tectonic movements". Well developed superimposed metallogenic systems have constituted one of the regional metallogenic features in China. Through the study on superimposed metallogenic system of the middle and lower reaches of the Yangtze River and of the Yuebei basin (northern Guangdong Province), the authors put forward some basic combination pattern of sedimentary-magmatic superimposed metallogenic system and summarize its forming conditions (controlling factors).
14. Intraoral 3D scanner
Science.gov (United States)
Kühmstedt, Peter; Bräuer-Burchardt, Christian; Munkelt, Christoph; Heinze, Matthias; Palme, Martin; Schmidt, Ingo; Hintersehr, Josef; Notni, Gunther
2007-09-01
Here a new set-up of a 3D-scanning system for CAD/CAM in dental industry is proposed. The system is designed for direct scanning of the dental preparations within the mouth. The measuring process is based on phase correlation technique in combination with fast fringe projection in a stereo arrangement. The novelty in the approach is characterized by the following features: A phase correlation between the phase values of the images of two cameras is used for the co-ordinate calculation. This works contrary to the usage of only phase values (phasogrammetry) or classical triangulation (phase values and camera image co-ordinate values) for the determination of the co-ordinates. The main advantage of the method is that the absolute value of the phase at each point does not directly determine the coordinate. Thus errors in the determination of the co-ordinates are prevented. Furthermore, using the epipolar geometry of the stereo-like arrangement the phase unwrapping problem of fringe analysis can be solved. The endoscope like measurement system contains one projection and two camera channels for illumination and observation of the object, respectively. The new system has a measurement field of nearly 25mm × 15mm. The user can measure two or three teeth at one time. So the system can by used for scanning of single tooth up to bridges preparations. In the paper the first realization of the intraoral scanner is described.
15. 3D video
CERN Document Server
Lucas, Laurent; Loscos, Céline
2013-01-01
While 3D vision has existed for many years, the use of 3D cameras and video-based modeling by the film industry has induced an explosion of interest for 3D acquisition technology, 3D content and 3D displays. As such, 3D video has become one of the new technology trends of this century.The chapters in this book cover a large spectrum of areas connected to 3D video, which are presented both theoretically and technologically, while taking into account both physiological and perceptual aspects. Stepping away from traditional 3D vision, the authors, all currently involved in these areas, provide th
16. 3D Animation Essentials
CERN Document Server
Beane, Andy
2012-01-01
The essential fundamentals of 3D animation for aspiring 3D artists 3D is everywhere--video games, movie and television special effects, mobile devices, etc. Many aspiring artists and animators have grown up with 3D and computers, and naturally gravitate to this field as their area of interest. Bringing a blend of studio and classroom experience to offer you thorough coverage of the 3D animation industry, this must-have book shows you what it takes to create compelling and realistic 3D imagery. Serves as the first step to understanding the language of 3D and computer graphics (CG)Covers 3D anim
17. EUROPEANA AND 3D
Directory of Open Access Journals (Sweden)
D. Pletinckx
2012-09-01
Full Text Available The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.
18. IZDELAVA TISKALNIKA 3D
OpenAIRE
Brdnik, Lovro
2015-01-01
Diplomsko delo analizira trenutno stanje 3D tiskalnikov na trgu. Prikazan je razvoj in principi delovanja 3D tiskalnikov. Predstavljeni so tipi 3D tiskalnikov, njihove prednosti in slabosti. Podrobneje je predstavljena zgradba in delovanje koračnih motorjev. Opravljene so meritve koračnih motorjev. Opisana je programska oprema za rokovanje s 3D tiskalniki in komponente, ki jih potrebujemo za izdelavo. Diploma se oklepa vprašanja, ali je izdelava 3D tiskalnika bolj ekonomična kot pa naložba v ...
19. 3D and Education
Science.gov (United States)
Meulien Ohlmann, Odile
2013-02-01
Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?
20. TEHNOLOGIJE 3D TISKALNIKOV
OpenAIRE
Kolar, Nataša
2016-01-01
Diplomsko delo predstavi razvoj tiskanja skozi čas. Podrobneje so opisani 3D tiskalniki, ki uporabljajo različne tehnologije 3D tiskanja. Predstavljene so različne tehnologije 3D tiskanja, njihova uporaba in narejeni prototipi oz. končni izdelki. Diplomsko delo opiše celoten postopek, od zamisli, priprave podatkov in tiskalnika do izdelave prototipa oz. končnega izdelka.
1. 3D virtuel udstilling
DEFF Research Database (Denmark)
Tournay, Bruno; Rüdiger, Bjarne
2006-01-01
3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s.......3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s....
2. 3D surface topography formation in ultra-precision turning
Institute of Scientific and Technical Information of China (English)
李丽伟; 董申; 程凯
2004-01-01
The generation process of 3 D surface topography in ultra-precision turning is analyzed, as the result of superimposing between actual roughness surface, waviness surface and geometrical form texture surface. From the viewpoints of machine technical system and manufacturing process, factors influencing on roughness surface,waviness surface and geometrical form texture surface in ultra-precision turning are discussed further. The 3D topography of ideal roughness surface and actual surface affected by cutting vibration are simulated respectively.
3. Blender 3D cookbook
CERN Document Server
Valenza, Enrico
2015-01-01
This book is aimed at the professionals that already have good 3D CGI experience with commercial packages and have now decided to try the open source Blender and want to experiment with something more complex than the average tutorials on the web. However, it's also aimed at the intermediate Blender users who simply want to go some steps further.It's taken for granted that you already know how to move inside the Blender interface, that you already have 3D modeling knowledge, and also that of basic 3D modeling and rendering concepts, for example, edge-loops, n-gons, or samples. In any case, it'
4. 3D Digital Modelling
DEFF Research Database (Denmark)
Hundebøl, Jesper
wave of new building information modelling tools demands further investigation, not least because of industry representatives' somewhat coarse parlance: Now the word is spreading -3D digital modelling is nothing less than a revolution, a shift of paradigm, a new alphabet... Research qeustions. Based...... on empirical probes (interviews, observations, written inscriptions) within the Danish construction industry this paper explores the organizational and managerial dynamics of 3D Digital Modelling. The paper intends to - Illustrate how the network of (non-)human actors engaged in the promotion (and arrest) of 3......D Modelling (in Denmark) stabilizes - Examine how 3D Modelling manifests itself in the early design phases of a construction project with a view to discuss the effects hereof for i.a. the management of the building process. Structure. The paper introduces a few, basic methodological concepts...
5. DELTA 3D PRINTER
Directory of Open Access Journals (Sweden)
ȘOVĂILĂ Florin
2016-07-01
Full Text Available 3D printing is a very used process in industry, the generic name being “rapid prototyping”. The essential advantage of a 3D printer is that it allows the designers to produce a prototype in a very short time, which is tested and quickly remodeled, considerably reducing the required time to get from the prototype phase to the final product. At the same time, through this technique we can achieve components with very precise forms, complex pieces that, through classical methods, could have been accomplished only in a large amount of time. In this paper, there are presented the stages of a 3D model execution, also the physical achievement after of a Delta 3D printer after the model.
6. Professional Papervision3D
CERN Document Server
Lively, Michael
2010-01-01
Professional Papervision3D describes how Papervision3D works and how real world applications are built, with a clear look at essential topics such as building websites and games, creating virtual tours, and Adobe's Flash 10. Readers learn important techniques through hands-on applications, and build on those skills as the book progresses. The companion website contains all code examples, video step-by-step explanations, and a collada repository.
7. AE3D
Energy Technology Data Exchange (ETDEWEB)
2016-06-20
AE3D solves for the shear Alfven eigenmodes and eigenfrequencies in a torodal magnetic fusion confinement device. The configuration can be either 2D (e.g. tokamak, reversed field pinch) or 3D (e.g. stellarator, helical reversed field pinch, tokamak with ripple). The equations solved are based on a reduced MHD model and sound wave coupling effects are not currently included.
8. A View to the Future: A Novel Approach for 3D-3D Superimposition and Quantification of Differences for Identification from Next-Generation Video Surveillance Systems.
Science.gov (United States)
Gibelli, Daniele; De Angelis, Danilo; Poppa, Pasquale; Sforza, Chiarella; Cattaneo, Cristina
2017-03-01
Techniques of 2D-3D superimposition are widely used in cases of personal identification from video surveillance systems. However, the progressive improvement of 3D image acquisition technology will enable operators to perform also 3D-3D facial superimposition. This study aims at analyzing the possible applications of 3D-3D superimposition to personal identification, although from a theoretical point of view. Twenty subjects underwent a facial 3D scan by stereophotogrammetry twice at different time periods. Scans were superimposed two by two according to nine landmarks, and root-mean-square (RMS) value of point-to-point distances was calculated. When the two superimposed models belonged to the same individual, RMS value was 2.10 mm, while it was 4.47 mm in mismatches with a statistically significant difference (p forensic practice. © 2016 American Academy of Forensic Sciences.
9. 3D Projection Installations
DEFF Research Database (Denmark)
Halskov, Kim; Johansen, Stine Liv; Bach Mikkelsen, Michelle
2014-01-01
Three-dimensional projection installations are particular kinds of augmented spaces in which a digital 3-D model is projected onto a physical three-dimensional object, thereby fusing the digital content and the physical object. Based on interaction design research and media studies, this article...... contributes to the understanding of the distinctive characteristics of such a new medium, and identifies three strategies for designing 3-D projection installations: establishing space; interplay between the digital and the physical; and transformation of materiality. The principal empirical case, From...... Fingerplan to Loop City, is a 3-D projection installation presenting the history and future of city planning for the Copenhagen area in Denmark. The installation was presented as part of the 12th Architecture Biennale in Venice in 2010....
10. 3D Spectroscopic Instrumentation
CERN Document Server
2009-01-01
In this Chapter we review the challenges of, and opportunities for, 3D spectroscopy, and how these have lead to new and different approaches to sampling astronomical information. We describe and categorize existing instruments on 4m and 10m telescopes. Our primary focus is on grating-dispersed spectrographs. We discuss how to optimize dispersive elements, such as VPH gratings, to achieve adequate spectral resolution, high throughput, and efficient data packing to maximize spatial sampling for 3D spectroscopy. We review and compare the various coupling methods that make these spectrographs 3D,'' including fibers, lenslets, slicers, and filtered multi-slits. We also describe Fabry-Perot and spatial-heterodyne interferometers, pointing out their advantages as field-widened systems relative to conventional, grating-dispersed spectrographs. We explore the parameter space all these instruments sample, highlighting regimes open for exploitation. Present instruments provide a foil for future development. We give an...
Science.gov (United States)
Oldham, Mark
2015-01-01
12. Interaktiv 3D design
DEFF Research Database (Denmark)
Villaume, René Domine; Ørstrup, Finn Rude
2002-01-01
Projektet undersøger potentialet for interaktiv 3D design via Internettet. Arkitekt Jørn Utzons projekt til Espansiva blev udviklet som et byggesystem med det mål, at kunne skabe mangfoldige planmuligheder og mangfoldige facade- og rumudformninger. Systemets bygningskomponenter er digitaliseret som...... 3D elementer og gjort tilgængelige. Via Internettet er det nu muligt at sammenstille og afprøve en uendelig række bygningstyper som systemet blev tænkt og udviklet til....
13. Dual side transparent OLED 3D display using Gabor super-lens
Science.gov (United States)
Chestak, Sergey; Kim, Dae-Sik; Cho, Sung-Woo
2015-03-01
We devised dual side transparent 3D display using transparent OLED panel and two lenticular arrays. The OLED panel is sandwiched between two parallel confocal lenticular arrays, forming Gabor super-lens. The display provides dual side stereoscopic 3D imaging and floating image of the object, placed behind it. The floating image can be superimposed with the displayed 3D image. The displayed autostereoscopic 3D images are composed of 4 views, each with resolution 64x90 pix.
14. Statistical properties of superimposed stationary spike trains.
Science.gov (United States)
Deger, Moritz; Helias, Moritz; Boucsein, Clemens; Rotter, Stefan
2012-06-01
The Poisson process is an often employed model for the activity of neuronal populations. It is known, though, that superpositions of realistic, non- Poisson spike trains are not in general Poisson processes, not even for large numbers of superimposed processes. Here we construct superimposed spike trains from intracellular in vivo recordings from rat neocortex neurons and compare their statistics to specific point process models. The constructed superimposed spike trains reveal strong deviations from the Poisson model. We find that superpositions of model spike trains that take the effective refractoriness of the neurons into account yield a much better description. A minimal model of this kind is the Poisson process with dead-time (PPD). For this process, and for superpositions thereof, we obtain analytical expressions for some second-order statistical quantities-like the count variability, inter-spike interval (ISI) variability and ISI correlations-and demonstrate the match with the in vivo data. We conclude that effective refractoriness is the key property that shapes the statistical properties of the superposition spike trains. We present new, efficient algorithms to generate superpositions of PPDs and of gamma processes that can be used to provide more realistic background input in simulations of networks of spiking neurons. Using these generators, we show in simulations that neurons which receive superimposed spike trains as input are highly sensitive for the statistical effects induced by neuronal refractoriness.
15. Paroxysmal Nocturnal Hemoglobinuria Superimposed with Preeclampsia
Directory of Open Access Journals (Sweden)
Mann-Ling Chen
2006-09-01
Conclusion: The most frequent causes of PNH-related fetomaternal morbidity and mortality are hemolysis and thrombosis. The situation becomes even more complicated when PNH is superimposed with preeclampsia. Appropriate clinical surveillance, awareness of the potential risks of hemolysis and thrombosis, as well as evaluation of fetal wellbeing are essential.
16. 3D Wire 2015
DEFF Research Database (Denmark)
Jordi, Moréton; F, Escribano; J. L., Farias
This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and ha......, improves socialization and networking, improves media impact, improves fun factor and improves encouragement of the production team....
17. Shaping 3-D boxes
DEFF Research Database (Denmark)
2011-01-01
Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data...
18. Tangible 3D Modelling
DEFF Research Database (Denmark)
2012-01-01
This paper presents an experimental approach to teaching 3D modelling techniques in an Industrial Design programme. The approach includes the use of tangible free form models as tools for improving the overall learning. The paper is based on lecturer and student experiences obtained through facil...
19. 3D photoacoustic imaging
Science.gov (United States)
Carson, Jeffrey J. L.; Roumeliotis, Michael; Chaudhary, Govind; Stodilka, Robert Z.; Anastasio, Mark A.
2010-06-01
Our group has concentrated on development of a 3D photoacoustic imaging system for biomedical imaging research. The technology employs a sparse parallel detection scheme and specialized reconstruction software to obtain 3D optical images using a single laser pulse. With the technology we have been able to capture 3D movies of translating point targets and rotating line targets. The current limitation of our 3D photoacoustic imaging approach is its inability ability to reconstruct complex objects in the field of view. This is primarily due to the relatively small number of projections used to reconstruct objects. However, in many photoacoustic imaging situations, only a few objects may be present in the field of view and these objects may have very high contrast compared to background. That is, the objects have sparse properties. Therefore, our work had two objectives: (i) to utilize mathematical tools to evaluate 3D photoacoustic imaging performance, and (ii) to test image reconstruction algorithms that prefer sparseness in the reconstructed images. Our approach was to utilize singular value decomposition techniques to study the imaging operator of the system and evaluate the complexity of objects that could potentially be reconstructed. We also compared the performance of two image reconstruction algorithms (algebraic reconstruction and l1-norm techniques) at reconstructing objects of increasing sparseness. We observed that for a 15-element detection scheme, the number of measureable singular vectors representative of the imaging operator was consistent with the demonstrated ability to reconstruct point and line targets in the field of view. We also observed that the l1-norm reconstruction technique, which is known to prefer sparseness in reconstructed images, was superior to the algebraic reconstruction technique. Based on these findings, we concluded (i) that singular value decomposition of the imaging operator provides valuable insight into the capabilities of
20. Unoriented 3d TFTs
CERN Document Server
Bhardwaj, Lakshya
2016-01-01
This paper generalizes two facts about oriented 3d TFTs to the unoriented case. On one hand, it is known that oriented 3d TFTs having a topological boundary condition admit a state-sum construction known as the Turaev-Viro construction. This is related to the string-net construction of fermionic phases of matter. We show how Turaev-Viro construction can be generalized to unoriented 3d TFTs. On the other hand, it is known that the "fermionic" versions of oriented TFTs, known as Spin-TFTs, can be constructed in terms of "shadow" TFTs which are ordinary oriented TFTs with an anomalous Z_2 1-form symmetry. We generalize this correspondence to Pin+ TFTs by showing that they can be constructed in terms of ordinary unoriented TFTs with anomalous Z_2 1-form symmetry having a mixed anomaly with time-reversal symmetry. The corresponding Pin+ TFT does not have any anomaly for time-reversal symmetry however and hence it can be unambiguously defined on a non-orientable manifold. In case a Pin+ TFT admits a topological bou...
1. POWER ALLOCATION OF DATA DEPENDENT SUPERIMPOSED TRAINING
Institute of Scientific and Technical Information of China (English)
Wang Ping; Yuan Weina; Fan Pingzhi
2008-01-01
Data Dependent Superimposed Training (DDST) scheme outperforms the traditional superimposed training by fully canceling the effects of unknown data in channel estimator. In DDST,however,the channel estimation accuracy and the data detection or channel equalization performance are affected significantly by the amount of power allocated to data and superimposed training sequence,which is the motivation of this research. In general,for DDST,there is a tradeoff between the channel estimation accuracy and the data detection reliability,i.e.,the more accurate the channel estimation,the more reliable the data detection; on the other hand,the more accurate the channel estimation,the more demanding on the power consumption of training sequence,which in turn leads to the less reliable data detection. In this paper,the relationship between the Signal-to-Noise Ratio (SNR) of the data detector and the training sequence power is analyzed. The optimal power allocation of the training sequence is derived based on the criterion of maximizing SNR of the detector. Analysis and simulation results show that for a fixed transmit power,the SNR and the Symbol Error Rate (SER) of detector vary nonlinearly with the increasing of training sequence power,and there exists an optimal power ratio,which accords with the derived optimal power ratio,among the data and training sequence.
2. 3D and beyond
Science.gov (United States)
Fung, Y. C.
1995-05-01
This conference on physiology and function covers a wide range of subjects, including the vasculature and blood flow, the flow of gas, water, and blood in the lung, the neurological structure and function, the modeling, and the motion and mechanics of organs. Many technologies are discussed. I believe that the list would include a robotic photographer, to hold the optical equipment in a precisely controlled way to obtain the images for the user. Why are 3D images needed? They are to achieve certain objectives through measurements of some objects. For example, in order to improve performance in sports or beauty of a person, we measure the form, dimensions, appearance, and movements.
3. 3D Surgical Simulation
Science.gov (United States)
Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael
2009-01-01
This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3D surface models from Cone-beam CT (CBCT), dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and 3D positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308
4. TOWARDS: 3D INTERNET
Directory of Open Access Journals (Sweden)
2013-08-01
Full Text Available In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot of discussions. Basically, one can look into this matter from a few different perspectives: visualization and representation of information, and creation and transportation of information, among others. All of them still constitute research challenges, as no products or services are yet available or foreseen for the near future. Nevertheless, one can try to envisage the directions that can be taken towards achieving this goal. People who take part in virtual worlds stay online longer with a heightened level of interest. To take advantage of that interest, diverse businesses and organizations have claimed an early stake in this fast-growing market. They include technology leaders such as IBM, Microsoft, and Cisco, companies such as BMW, Toyota, Circuit City, Coca Cola, and Calvin Klein, and scores of universities, including Harvard, Stanford and Penn State.
5. 3D-kompositointi
OpenAIRE
Piirainen, Jere
2015-01-01
Opinnäytetyössä käydään läpi yleisimpiä 3D-kompositointiin liittyviä tekniikoita sekä kompositointiin käytettyjä ohjelmia ja liitännäisiä. Työssä esitellään myös kompositoinnin juuret 1800-luvun lopulta aina nykyaikaiseen digitaaliseen kompositointiin asti. Kompositointi on yksinkertaisimmillaan usean kuvan liittämistä saumattomasti yhdeksi uskottavaksi kokonaisuudeksi. Vaikka prosessi vaatii visuaalista silmää, vaatii se myös paljon teknistä osaamista. Tämän lisäksi perusymmärrys kamera...
6. Shaping 3-D boxes
DEFF Research Database (Denmark)
2011-01-01
Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data......, making them different from typical, existing box shaping techniques. The basis of the proposed techniques is a new algorithm for constructing a full box from just three of its corners. The evaluation of the new techniques compares their precision and completion times in a 9 degree-of-freedom (Do......F) docking experiment against an existing technique, which requires the user to perform the rotation and scaling of the box explicitly. The precision of the users' box construction is evaluated by a novel error metric measuring the difference between two boxes. The results of the experiment strongly indicate...
7. Photogrammetric 3D skull/photo superimposition: A pilot study.
Science.gov (United States)
Santoro, Valeria; Lubelli, Sergio; De Donno, Antonio; Inchingolo, Alessio; Lavecchia, Fulvio; Introna, Francesco
2017-02-13
The identification of bodies through the examination of skeletal remains holds a prominent place in the field of forensic investigations. Technological advancements in 3D facial acquisition techniques have led to the proposal of a new body identification technique that involves a combination of craniofacial superimposition and photogrammetry. The aim of this study was to test the method by superimposing various computerized 3D images of skulls onto various photographs of missing people taken while they were still alive in cases when there was a suspicion that the skulls in question belonged to them. The technique is divided into four phases: preparatory phase, 3d acquisition phase, superimposition phase, and metric image analysis 3d. The actual superimposition of the images was carried out in the fourth step. and was done so by comparing the skull images with the selected photos. Using a specific software, the two images (i.e. the 3D avatar and the photo of the missing person) were superimposed. Cross-comparisons of 5 skulls discovered in a mass grave, and of 2 skulls retrieved in the crawlspace of a house were performed. The morphologyc phase reveals a full overlap between skulls and photos of disappeared persons. Metric phase reveals that correlation coefficients of this values, higher than 0.998-0,997 allow to confirm identification hypothesis.
8. Voro3D: 3D Voronoi tessellations applied to protein structures.
Science.gov (United States)
Dupuis, Franck; Sadoc, Jean-François; Jullien, Rémi; Angelov, Borislav; Mornon, Jean-Paul
2005-04-15
Voro3D is an original easy-to-use tool, which provides a brand new point of view on protein structures through the three-dimensional (3D) Voronoi tessellations. To construct the Voronoi cells associated with each amino acid by a number of different tessellation methods, Voro3D uses a protein structure file in the PDB format as an input. After calculation, different structural properties of interest like secondary structures assignment, environment accessibility and exact contact matrices can be derived without any geometrical cut-off. Voro3D provides also a visualization of these tessellations superimposed on the associated protein structure, from which it is possible to model a polygonal protein surface using a model solvent or to quantify, for instance, the contact areas between a protein and a ligand. The software executable file for PC using Windows 98, 2000, NT, XP can be freely downloaded at http://www.lmcp.jussieu.fr/~mornon/voronoi.html [email protected]; [email protected].
9. 3D culture for cardiac cells.
Science.gov (United States)
Zuppinger, Christian
2016-07-01
This review discusses historical milestones, recent developments and challenges in the area of 3D culture models with cardiovascular cell types. Expectations in this area have been raised in recent years, but more relevant in vitro research, more accurate drug testing results, reliable disease models and insights leading to bioartificial organs are expected from the transition to 3D cell culture. However, the construction of organ-like cardiac 3D models currently remains a difficult challenge. The heart consists of highly differentiated cells in an intricate arrangement.Furthermore, electrical “wiring”, a vascular system and multiple cell types act in concert to respond to the rapidly changing demands of the body. Although cardiovascular 3D culture models have been predominantly developed for regenerative medicine in the past, their use in drug screening and for disease models has become more popular recently. Many sophisticated 3D culture models are currently being developed in this dynamic area of life science. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
10. Martian terrain - 3D
Science.gov (United States)
1997-01-01
This area of terrain near the Sagan Memorial Station was taken on Sol 3 by the Imager for Mars Pathfinder (IMP). 3D glasses are necessary to identify surface detail.The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right
11. 3D Printing and 3D Bioprinting in Pediatrics.
Science.gov (United States)
Vijayavenkataraman, Sanjairaj; Fuh, Jerry Y H; Lu, Wen Feng
2017-07-13
Additive manufacturing, commonly referred to as 3D printing, is a technology that builds three-dimensional structures and components layer by layer. Bioprinting is the use of 3D printing technology to fabricate tissue constructs for regenerative medicine from cell-laden bio-inks. 3D printing and bioprinting have huge potential in revolutionizing the field of tissue engineering and regenerative medicine. This paper reviews the application of 3D printing and bioprinting in the field of pediatrics.
12. 3D printing for dummies
CERN Document Server
Hausman, Kalani Kirk
2014-01-01
Get started printing out 3D objects quickly and inexpensively! 3D printing is no longer just a figment of your imagination. This remarkable technology is coming to the masses with the growing availability of 3D printers. 3D printers create 3-dimensional layered models and they allow users to create prototypes that use multiple materials and colors. This friendly-but-straightforward guide examines each type of 3D printing technology available today and gives artists, entrepreneurs, engineers, and hobbyists insight into the amazing things 3D printing has to offer. You'll discover methods for
13. Comparison of different undulator schemes with superimposed alternating gradients for the VUV-FEL at the TESLA Test Facility
Energy Technology Data Exchange (ETDEWEB)
Pflueger, J.; Nikitina, Y.M. [DESY/HASYLAB, Hamburg (Germany)
1995-12-31
For the VUV-FEL at the TESLA Test Facility an undulator with a total length of 30 m is needed. In this study three different approaches to realize an undulator with a sinusoidal plus a superimposed quadrupolar field were studied with the 3D code MAFIA.
14. 3-D template simulation system in Total Hip Arthroplasty
Energy Technology Data Exchange (ETDEWEB)
Tanaka, Nobuhiko [Nagoya City Univ. (Japan). Medical School
2000-09-01
In Total Hip Arthroplastry, 2D template on Plain X-ray is usually used for preoperative planning. But deformity and contracture can cause malposition and measurement error. To reduce those problems, a 3D preoperative simulation system was developed. Three methods were compared in this study. One is to create very accurate AP and ML images which can use for standard 2D template. One is fully 3D preoperative template system using computer graphics. Last one is substantial simulation using stereo-lithography model. 3D geometry data of the bone was made from Helical 3-D CT data. AP and ML surface cutting 3D images of the femur were created using workstation (Advantage Workstation; GE Medical Systems). The extracted 3D geometry was displayed on personal computer using Magics (STL data visualization software), then 3D geometry of the stem was superimposed in it. The full 3D simulation system made it possible to observe the bone and stem geometry from any direction and by any section view. Stereo-lithography model was useful for detailed observation of the femur anatomy. (author)
15. 3D game environments create professional 3D game worlds
CERN Document Server
Ahearn, Luke
2008-01-01
The ultimate resource to help you create triple-A quality art for a variety of game worlds; 3D Game Environments offers detailed tutorials on creating 3D models, applying 2D art to 3D models, and clear concise advice on issues of efficiency and optimization for a 3D game engine. Using Photoshop and 3ds Max as his primary tools, Luke Ahearn explains how to create realistic textures from photo source and uses a variety of techniques to portray dynamic and believable game worlds.From a modern city to a steamy jungle, learn about the planning and technological considerations for 3D modelin
16. 3D Printing an Octohedron
OpenAIRE
2014-01-01
The purpose of this short paper is to describe a project to manufacture a regular octohedron on a 3D printer. We assume that the reader is familiar with the basics of 3D printing. In the project, we use fundamental ideas to calculate the vertices and faces of an octohedron. Then, we utilize the OPENSCAD program to create a virtual 3D model and an STereoLithography (.stl) file that can be used by a 3D printer.
17. Salient Local 3D Features for 3D Shape Retrieval
CERN Document Server
Godil, Afzal
2011-01-01
In this paper we describe a new formulation for the 3D salient local features based on the voxel grid inspired by the Scale Invariant Feature Transform (SIFT). We use it to identify the salient keypoints (invariant points) on a 3D voxelized model and calculate invariant 3D local feature descriptors at these keypoints. We then use the bag of words approach on the 3D local features to represent the 3D models for shape retrieval. The advantages of the method are that it can be applied to rigid as well as to articulated and deformable 3D models. Finally, this approach is applied for 3D Shape Retrieval on the McGill articulated shape benchmark and then the retrieval results are presented and compared to other methods.
18. Superimposed MRSA infection of vulvar eczematous dermatitis
Science.gov (United States)
Carey, Erin; Zedek, Daniel; Lewis, Jasmine; Zolnoun, Denniz
2014-01-01
Background Vulvar eczematous dermatitis predisposes patients to superimposed infections, which may result in late diagnosis and architectural destruction. Methicillin resistant staphylococcus aureus (MRSA) infection is on the rise in genitalia and lower extremities. Case 44 year-old female presented with recurrent vulvar lesions and pain. A diagnosis of methicillin resistant staphylococcus aureus in the setting of eczema was achieved with concomitant use of photography and dermatopathologic review. Antibiotics were tailored to the resistant infection and preventative moisturization therapy was utilized. Conclusion Awareness of dermatologic conditions affecting the vulva is principal in routine gynecologic care. Barrier protection of eczematous vulvar skin may prevent superficial infections. The regular use of photographic documentation and dermatopathology may decrease time to diagnosis with infrequent conditions. PMID:23763013
19. Holography of 3d-3d correspondence at Large N
OpenAIRE
Gang, Dongmin; Kim, Nakwoo; Lee, Sangmin
2014-01-01
We study the physics of multiple M5-branes compactified on a hyperbolic 3-manifold. On the one hand, it leads to the 3d-3d correspondence which maps an N = 2 $$\\mathcal{N}=2$$ superconformal field theory to a pure Chern-Simons theory on the 3-manifold. On the other hand, it leads to a warped AdS 4 geometry in M-theory holographically dual to the superconformal field theory. Combining the holographic duality and the 3d-3d correspondence, we propose a conjecture for the large N limit of the p...
20. Natural 3D content on glasses-free light-field 3D cinema
Science.gov (United States)
Balogh, Tibor; Nagy, Zsolt; Kovács, Péter Tamás.; Adhikarla, Vamsi K.
2013-03-01
This paper presents a complete framework for capturing, processing and displaying the free viewpoint video on a large scale immersive light-field display. We present a combined hardware-software solution to visualize free viewpoint 3D video on a cinema-sized screen. The new glasses-free 3D projection technology can support larger audience than the existing autostereoscopic displays. We introduce and describe our new display system including optical and mechanical design considerations, the capturing system and render cluster for producing the 3D content, and the various software modules driving the system. The indigenous display is first of its kind, equipped with front-projection light-field HoloVizio technology, controlling up to 63 MP. It has all the advantages of previous light-field displays and in addition, allows a more flexible arrangement with a larger screen size, matching cinema or meeting room geometries, yet simpler to set-up. The software system makes it possible to show 3D applications in real-time, besides the natural content captured from dense camera arrangements as well as from sparse cameras covering a wider baseline. Our software system on the GPU accelerated render cluster, can also visualize pre-recorded Multi-view Video plus Depth (MVD4) videos on this light-field glasses-free cinema system, interpolating and extrapolating missing views.
1. Effect of Superimposed Hydrostatic Pressure on Bendability of Sheet Metals
Science.gov (United States)
Chen, X. X.; Wu, P. D.; Lloyd, D. J.
2010-06-01
The effect of superimposed hydrostatic pressure on fracture under three-point bending is studied numerically using the finite element method based on the Gurson damage model. It is demonstrated that superimposed hydrostatic pressure significantly increases the bendability and bending fracture strain due to the fact that a superimposed pressure delays or completely eliminates the nucleation, growth and coalescence of microvoids or microcracks. Numerical results are found to be in good agreement with experimental observations.
2. 3D Spectroscopy in Astronomy
Science.gov (United States)
Mediavilla, Evencio; Arribas, Santiago; Roth, Martin; Cepa-Nogué, Jordi; Sánchez, Francisco
2011-09-01
Preface; Acknowledgements; 1. Introductory review and technical approaches Martin M. Roth; 2. Observational procedures and data reduction James E. H. Turner; 3. 3D Spectroscopy instrumentation M. A. Bershady; 4. Analysis of 3D data Pierre Ferruit; 5. Science motivation for IFS and galactic studies F. Eisenhauer; 6. Extragalactic studies and future IFS science Luis Colina; 7. Tutorials: how to handle 3D spectroscopy data Sebastian F. Sánchez, Begona García-Lorenzo and Arlette Pécontal-Rousset.
3. Spherical 3D isotropic wavelets
Science.gov (United States)
Lanusse, F.; Rassat, A.; Starck, J.-L.
2012-04-01
Context. Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D spherical Fourier-Bessel (SFB) analysis in spherical coordinates is natural. Wavelets are particularly well-suited to the analysis and denoising of cosmological data, but a spherical 3D isotropic wavelet transform does not currently exist to analyse spherical 3D data. Aims: The aim of this paper is to present a new formalism for a spherical 3D isotropic wavelet, i.e. one based on the SFB decomposition of a 3D field and accompany the formalism with a public code to perform wavelet transforms. Methods: We describe a new 3D isotropic spherical wavelet decomposition based on the undecimated wavelet transform (UWT) described in Starck et al. (2006). We also present a new fast discrete spherical Fourier-Bessel transform (DSFBT) based on both a discrete Bessel transform and the HEALPIX angular pixelisation scheme. We test the 3D wavelet transform and as a toy-application, apply a denoising algorithm in wavelet space to the Virgo large box cosmological simulations and find we can successfully remove noise without much loss to the large scale structure. Results: We have described a new spherical 3D isotropic wavelet transform, ideally suited to analyse and denoise future 3D spherical cosmological surveys, which uses a novel DSFBT. We illustrate its potential use for denoising using a toy model. All the algorithms presented in this paper are available for download as a public code called MRS3D at http://jstarck.free.fr/mrs3d.html
4. 3D IBFV : Hardware-Accelerated 3D Flow Visualization
NARCIS (Netherlands)
Telea, Alexandru; Wijk, Jarke J. van
2003-01-01
We present a hardware-accelerated method for visualizing 3D flow fields. The method is based on insertion, advection, and decay of dye. To this aim, we extend the texture-based IBFV technique for 2D flow visualization in two main directions. First, we decompose the 3D flow visualization problem in a
5. 3D Elevation Program—Virtual USA in 3D
Science.gov (United States)
Lukas, Vicki; Stoker, J.M.
2016-04-14
The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.
6. A 3-D Contextual Classifier
DEFF Research Database (Denmark)
Larsen, Rasmus
1997-01-01
. This includes the specification of a Gaussian distribution for the pixel values as well as a prior distribution for the configuration of class variables within the cross that is m ade of a pixel and its four nearest neighbours. We will extend this algorithm to 3-D, i.e. we will specify a simultaneous Gaussian...... distr ibution for a pixel and its 6 nearest 3-D neighbours, and generalise the class variable configuration distribution within the 3-D cross. The algorithm is tested on a synthetic 3-D multivariate dataset....
7. 3D Bayesian contextual classifiers
DEFF Research Database (Denmark)
Larsen, Rasmus
2000-01-01
We extend a series of multivariate Bayesian 2-D contextual classifiers to 3-D by specifying a simultaneous Gaussian distribution for the feature vectors as well as a prior distribution of the class variables of a pixel and its 6 nearest 3-D neighbours.......We extend a series of multivariate Bayesian 2-D contextual classifiers to 3-D by specifying a simultaneous Gaussian distribution for the feature vectors as well as a prior distribution of the class variables of a pixel and its 6 nearest 3-D neighbours....
8. Using 3D in Visualization
DEFF Research Database (Denmark)
Wood, Jo; Kirschenbauer, Sabine; Döllner, Jürgen
2005-01-01
to display 3D imagery. The extra cartographic degree of freedom offered by using 3D is explored and offered as a motivation for employing 3D in visualization. The use of VR and the construction of virtual environments exploit navigational and behavioral realism, but become most usefil when combined...... with abstracted representations embedded in a 3D space. The interactions between development of geovisualization, the technology used to implement it and the theory surrounding cartographic representation are explored. The dominance of computing technologies, driven particularly by the gaming industry...
9. Interactive 3D multimedia content
CERN Document Server
Cellary, Wojciech
2012-01-01
The book describes recent research results in the areas of modelling, creation, management and presentation of interactive 3D multimedia content. The book describes the current state of the art in the field and identifies the most important research and design issues. Consecutive chapters address these issues. These are: database modelling of 3D content, security in 3D environments, describing interactivity of content, searching content, visualization of search results, modelling mixed reality content, and efficient creation of interactive 3D content. Each chapter is illustrated with example a
10. 3D for Graphic Designers
CERN Document Server
Connell, Ellery
2011-01-01
Helping graphic designers expand their 2D skills into the 3D space The trend in graphic design is towards 3D, with the demand for motion graphics, animation, photorealism, and interactivity rapidly increasing. And with the meteoric rise of iPads, smartphones, and other interactive devices, the design landscape is changing faster than ever.2D digital artists who need a quick and efficient way to join this brave new world will want 3D for Graphic Designers. Readers get hands-on basic training in working in the 3D space, including product design, industrial design and visualization, modeling, ani
11. 3-D printers for libraries
CERN Document Server
Griffey, Jason
2014-01-01
As the maker movement continues to grow and 3-D printers become more affordable, an expanding group of hobbyists is keen to explore this new technology. In the time-honored tradition of introducing new technologies, many libraries are considering purchasing a 3-D printer. Jason Griffey, an early enthusiast of 3-D printing, has researched the marketplace and seen several systems first hand at the Consumer Electronics Show. In this report he introduces readers to the 3-D printing marketplace, covering such topics asHow fused deposition modeling (FDM) printing workBasic terminology such as build
12. 3D-Measuring for Head Shape Covering Hair
Science.gov (United States)
Kato, Tsukasa; Hattori, Koosuke; Nomura, Takuya; Taguchi, Ryo; Hoguro, Masahiro; Umezaki, Taizo
3D-Measuring is paid to attention because 3D-Display is making rapid spread. Especially, face and head are required to be measured because of necessary or contents production. However, it is a present problem that it is difficult to measure hair. Then, in this research, it is a purpose to measure face and hair with phase shift method. By using sine images arranged for hair measuring, the problems on hair measuring, dark color and reflection, are settled.
13. 3D fascicle orientations in triceps surae.
Science.gov (United States)
Rana, Manku; Hamarneh, Ghassan; Wakeling, James M
2013-07-01
The aim of this study was to determine the three-dimensional (3D) muscle fascicle architecture in human triceps surae muscles at different contraction levels and muscle lengths. Six male subjects were tested for three contraction levels (0, 30, and 60% of maximal voluntary contraction) and four ankle angles (-15, 0, 15, and 30° of plantar flexion), and the muscles were imaged with B-mode ultrasound coupled to 3D position sensors. 3D fascicle orientations were represented in terms of pennation angle relative to the major axis of the muscle and azimuthal angle (a new architectural parameter introduced in this study representing the radial angle around the major axis). 3D orientations of the fascicles, and the sheets along which they lie, were regionalized in all the three muscles (medial and lateral gastrocnemius and the soleus) and changed significantly with contraction level and ankle angle. Changes in the azimuthal angle were of similar magnitude to the changes in pennation angle. The 3D information was used for an error analysis to determine the errors in predictions of pennation that would occur in purely two-dimensional studies. A comparison was made for assessing pennation in the same plane for different contraction levels, or for adjusting the scanning plane orientation for different contractions: there was no significant difference between the two simulated scanning conditions for the gastrocnemii; however, a significant difference of 4.5° was obtained for the soleus. Correct probe orientation is thus more critical during estimations of pennation for the soleus than the gastrocnemii due to its more complex fascicle arrangement.
14. 3D roadmap in neuroangiography: technique and clinical interest
Energy Technology Data Exchange (ETDEWEB)
Soederman, Michael; Andersson, T. [Karolinska Hospital, Department of Neuroradiology, Stockholm (Sweden); Babic, D.; Homan, R. [Philips Medical Systems, Best (Netherlands)
2005-10-01
We present the first clinical results obtained with a novel technique: the three-dimensional [3D] roadmap. The major difference from the standard 2D digital roadmap technique is that the newly developed 3D roadmap is based on a rotational angiography acquisition technique with the two-dimensional [2D] fluoroscopic image as an overlay. Data required for an accurate superimposition of the previously acquired 3D reconstructed image on the interactively made 2D fluoroscopy image, in real time, are stored in the 3D workstation and constitute the calibration dataset. Both datasets are spatially aligned in real time; thus, the 3D image is accurately superimposed on the 2D fluoroscopic image regardless of any change in C-arm position or magnification. The principal advantage of the described roadmap method is that one contrast injection allows the C-arm to be positioned anywhere in the space and allows alterations in the distance between the x-ray tube and the image intensifier as well as changes in image magnification. In the clinical setting, the 3D roadmap facilitated intravascular neuronavigation with concurrent reduction of procedure time and use of contrast medium. (orig.)
15. Perception of 3D spatial relations for 3D displays
Science.gov (United States)
Rosen, Paul; Pizlo, Zygmunt; Hoffmann, Christoph; Popescu, Voicu S.
2004-05-01
We test perception of 3D spatial relations in 3D images rendered by a 3D display (Perspecta from Actuality Systems) and compare it to that of a high-resolution flat panel display. 3D images provide the observer with such depth cues as motion parallax and binocular disparity. Our 3D display is a device that renders a 3D image by displaying, in rapid succession, radial slices through the scene on a rotating screen. The image is contained in a glass globe and can be viewed from virtually any direction. In the psychophysical experiment several families of 3D objects are used as stimuli: primitive shapes (cylinders and cuboids), and complex objects (multi-story buildings, cars, and pieces of furniture). Each object has at least one plane of symmetry. On each trial an object or its "distorted" version is shown at an arbitrary orientation. The distortion is produced by stretching an object in a random direction by 40%. This distortion must eliminate the symmetry of an object. The subject's task is to decide whether or not the presented object is distorted under several viewing conditions (monocular/binocular, with/without motion parallax, and near/far). The subject's performance is measured by the discriminability d', which is a conventional dependent variable in signal detection experiments.
16. 3D Printing for Bricks
OpenAIRE
ECT Team, Purdue
2015-01-01
Building Bytes, by Brian Peters, is a project that uses desktop 3D printers to print bricks for architecture. Instead of using an expensive custom-made printer, it uses a normal standard 3D printer which is available for everyone and makes it more accessible and also easier for fabrication.
17. Market study: 3-D eyetracker
Science.gov (United States)
1977-01-01
A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.
18. Spherical 3D Isotropic Wavelets
CERN Document Server
Lanusse, F; Starck, J -L
2011-01-01
Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D Spherical Fourier-Bessel (SFB) analysis in is natural. Wavelets are particularly well-suited to the analysis and denoising of cosmological data, but a spherical 3D isotropic wavelet transform does not currently exist to analyse spherical 3D data. The aim of this paper is to present a new formalism for a spherical 3D isotropic wavelet, i.e. one based on the Fourier-Bessel decomposition of a 3D field and accompany the formalism with a public code to perform wavelet transforms. We describe a new 3D isotropic spherical wavelet decomposition based on the undecimated wavelet transform (UWT) described in Starck et al. 2006. We also present a new fast Discrete Spherical Fourier-Bessel Transform (DSFBT) based on both a discrete Bessel Transform and the HEALPIX angular pixelisation scheme. We test the 3D wavelet transform and as a toy-application, apply a denoising algorithm in wavelet space to the Virgo large...
19. Improvement of 3D Scanner
Institute of Scientific and Technical Information of China (English)
2003-01-01
The disadvantage remaining in 3D scanning system and its reasons are discussed. A new host-and-slave structure with high speed image acquisition and processing system is proposed to quicken the image processing and improve the performance of 3D scanning system.
DEFF Research Database (Denmark)
Rasmussen, Morten Fischer
to produce high quality 3-D images. Because of the large matrix transducers with integrated custom electronics, these systems are extremely expensive. The relatively low price of ultrasound scanners is one of the factors for the widespread use of ultrasound imaging. The high price tag on the high quality 3-D......The main purpose of the PhD project was to develop methods that increase the 3-D ultrasound imaging quality available for the medical personnel in the clinic. Acquiring a 3-D volume gives the medical doctor the freedom to investigate the measured anatomy in any slice desirable after the scan has...... been completed. This allows for precise measurements of organs dimensions and makes the scan more operator independent. Real-time 3-D ultrasound imaging is still not as widespread in use in the clinics as 2-D imaging. A limiting factor has traditionally been the low image quality achievable using...
1. Using 3D in Visualization
DEFF Research Database (Denmark)
Wood, Jo; Kirschenbauer, Sabine; Döllner, Jürgen
2005-01-01
The notion of three-dimensionality is applied to five stages of the visualization pipeline. While 3D visulization is most often associated with the visual mapping and representation of data, this chapter also identifies its role in the management and assembly of data, and in the media used...... to display 3D imagery. The extra cartographic degree of freedom offered by using 3D is explored and offered as a motivation for employing 3D in visualization. The use of VR and the construction of virtual environments exploit navigational and behavioral realism, but become most usefil when combined...... with abstracted representations embedded in a 3D space. The interactions between development of geovisualization, the technology used to implement it and the theory surrounding cartographic representation are explored. The dominance of computing technologies, driven particularly by the gaming industry...
2. 3D printing in dentistry.
Science.gov (United States)
Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A
2015-12-01
3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.
3. 3D vision system assessment
Science.gov (United States)
Pezzaniti, J. Larry; Edmondson, Richard; Vaden, Justin; Hyatt, Bryan; Chenault, David B.; Kingston, David; Geulen, Vanilynmae; Newell, Scott; Pettijohn, Brad
2009-02-01
In this paper, we report on the development of a 3D vision system consisting of a flat panel stereoscopic display and auto-converging stereo camera and an assessment of the system's use for robotic driving, manipulation, and surveillance operations. The 3D vision system was integrated onto a Talon Robot and Operator Control Unit (OCU) such that direct comparisons of the performance of a number of test subjects using 2D and 3D vision systems were possible. A number of representative scenarios were developed to determine which tasks benefited most from the added depth perception and to understand when the 3D vision system hindered understanding of the scene. Two tests were conducted at Fort Leonard Wood, MO with noncommissioned officers ranked Staff Sergeant and Sergeant First Class. The scenarios; the test planning, approach and protocols; the data analysis; and the resulting performance assessment of the 3D vision system are reported.
4. PLOT3D user's manual
Science.gov (United States)
Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.
1990-01-01
PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.
5. 3D space analysis of dental models
Science.gov (United States)
Chuah, Joon H.; Ong, Sim Heng; Kondo, Toshiaki; Foong, Kelvin W. C.; Yong, Than F.
2001-05-01
Space analysis is an important procedure by orthodontists to determine the amount of space available and required for teeth alignment during treatment planning. Traditional manual methods of space analysis are tedious and often inaccurate. Computer-based space analysis methods that work on 2D images have been reported. However, as the space problems in the dental arch exist in all three planes of space, a full 3D analysis of the problems is necessary. This paper describes a visualization and measurement system that analyses 3D images of dental plaster models. Algorithms were developed to determine dental arches. The system is able to record the depths of the Curve of Spee, and quantify space liabilities arising from a non-planar Curve of Spee, malalignment and overjet. Furthermore, the difference between total arch space available and the space required to arrange the teeth in ideal occlusion can be accurately computed. The system for 3D space analysis of the dental arch is an accurate, comprehensive, rapid and repeatable method of space analysis to facilitate proper orthodontic diagnosis and treatment planning.
6. ADT-3D Tumor Detection Assistant in 3D
Directory of Open Access Journals (Sweden)
Jaime Lazcano Bello
2008-12-01
Full Text Available The present document describes ADT-3D (Three-Dimensional Tumor Detector Assistant, a prototype application developed to assist doctors diagnose, detect and locate tumors in the brain by using CT scan. The reader may find on this document an introduction to tumor detection; ADT-3D main goals; development details; description of the product; motivation for its development; result’s study; and areas of applicability.
7. Unassisted 3D camera calibration
Science.gov (United States)
Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.
2012-03-01
With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.
8. Bioprinting of 3D hydrogels.
Science.gov (United States)
Stanton, M M; Samitier, J; Sánchez, S
2015-08-07
Three-dimensional (3D) bioprinting has recently emerged as an extension of 3D material printing, by using biocompatible or cellular components to build structures in an additive, layer-by-layer methodology for encapsulation and culture of cells. These 3D systems allow for cell culture in a suspension for formation of highly organized tissue or controlled spatial orientation of cell environments. The in vitro 3D cellular environments simulate the complexity of an in vivo environment and natural extracellular matrices (ECM). This paper will focus on bioprinting utilizing hydrogels as 3D scaffolds. Hydrogels are advantageous for cell culture as they are highly permeable to cell culture media, nutrients, and waste products generated during metabolic cell processes. They have the ability to be fabricated in customized shapes with various material properties with dimensions at the micron scale. 3D hydrogels are a reliable method for biocompatible 3D printing and have applications in tissue engineering, drug screening, and organ on a chip models.
9. Tuotekehitysprojekti: 3D-tulostin
OpenAIRE
Pihlajamäki, Janne
2011-01-01
Opinnäytetyössä tutustuttiin 3D-tulostamisen teknologiaan. Työssä käytiin läpi 3D-tulostimesta tehty tuotekehitysprojekti. Sen lisäksi esiteltiin yleisellä tasolla tuotekehitysprosessi ja syntyneiden tulosten mahdollisia suojausmenetelmiä. Tavoitteena tässä työssä oli kehittää markkinoilta jo löytyvää kotitulostin-tasoista 3D-laiteteknologiaa lähemmäksi ammattilaistason ratkaisua. Tavoitteeseen pyrittiin keskittymällä parantamaan laitteella saavutettavaa tulostustarkkuutta ja -nopeutt...
10. Color 3D Reverse Engineering
Institute of Scientific and Technical Information of China (English)
2002-01-01
This paper presents a principle and a method of col or 3D laser scanning measurement. Based on the fundamental monochrome 3D measureme nt study, color information capture, color texture mapping, coordinate computati on and other techniques are performed to achieve color 3D measurement. The syste m is designed and composed of a line laser light emitter, one color CCD camera, a motor-driven rotary filter, a circuit card and a computer. Two steps in captu ring object's images in the measurement process: Firs...
11. Exploration of 3D Printing
OpenAIRE
Lin, Zeyu
2014-01-01
3D printing technology is introduced and defined in this Thesis. Some methods of 3D printing are illustrated and their principles are explained with pictures. Most of the essential parts are presented with pictures and their effects are explained within the whole system. Problems on Up! Plus 3D printer are solved and a DIY product is made with this machine. The processes of making product are recorded and the items which need to be noticed during the process are the highlight in this th...
12. Handbook of 3D integration
CERN Document Server
Garrou , Philip; Ramm , Peter
2014-01-01
Edited by key figures in 3D integration and written by top authors from high-tech companies and renowned research institutions, this book covers the intricate details of 3D process technology.As such, the main focus is on silicon via formation, bonding and debonding, thinning, via reveal and backside processing, both from a technological and a materials science perspective. The last part of the book is concerned with assessing and enhancing the reliability of the 3D integrated devices, which is a prerequisite for the large-scale implementation of this emerging technology. Invaluable reading fo
13. Conducting polymer 3D microelectrodes
DEFF Research Database (Denmark)
Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi
2010-01-01
Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained...
14. Accepting the T3D
Energy Technology Data Exchange (ETDEWEB)
Rich, D.O.; Pope, S.C.; DeLapp, J.G.
1994-10-01
In April, a 128 PE Cray T3D was installed at Los Alamos National Laboratorys Advanced Computing Laboratory as part of the DOEs High-Performance Parallel Processor Program (H4P). In conjunction with CRI, the authors implemented a 30 day acceptance test. The test was constructed in part to help them understand the strengths and weaknesses of the T3D. In this paper, they briefly describe the H4P and its goals. They discuss the design and implementation of the T3D acceptance test and detail issues that arose during the test. They conclude with a set of system requirements that must be addressed as the T3D system evolves.
15. 3-D Vector Flow Imaging
DEFF Research Database (Denmark)
Holbek, Simon
For the last decade, the field of ultrasonic vector flow imaging has gotten an increasingly attention, as the technique offers a variety of new applications for screening and diagnostics of cardiovascular pathologies. The main purpose of this PhD project was therefore to advance the field of 3-D...... ultrasonic vector flow estimation and bring it a step closer to a clinical application. A method for high frame rate 3-D vector flow estimation in a plane using the transverse oscillation method combined with a 1024 channel 2-D matrix array is presented. The proposed method is validated both through phantom......, if this significant reduction in the element count can still provide precise and robust 3-D vector flow estimates in a plane. The study concludes that the RC array is capable of estimating precise 3-D vector flow both in a plane and in a volume, despite the low channel count. However, some inherent new challenges...
16. 3D Face Apperance Model
DEFF Research Database (Denmark)
Lading, Brian; Larsen, Rasmus; Astrom, K
2006-01-01
We build a 3D face shape model, including inter- and intra-shape variations, derive the analytical Jacobian of its resulting 2D rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations......We build a 3D face shape model, including inter- and intra-shape variations, derive the analytical Jacobian of its resulting 2D rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations...
17. 3D Face Appearance Model
DEFF Research Database (Denmark)
Lading, Brian; Larsen, Rasmus; Åström, Kalle
2006-01-01
We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}......We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}...
18. Main: TATCCAYMOTIFOSRAMY3D [PLACE
Lifescience Database Archive (English)
Full Text Available TATCCAYMOTIFOSRAMY3D S000256 01-August-2006 (last modified) kehi TATCCAY motif foun...d in rice (O.s.) RAmy3D alpha-amylase gene promoter; Y=T/C; a GATA motif as its antisense sequence; TATCCAY ...motif and G motif (see S000130) are responsible for sugar repression (Toyofuku et al. 1998); GATA; amylase; sugar; repression; rice (Oryza sativa) TATCCAY ...
19. Classification of Complex Reservoirs in Superimposed Basins of Western China
Institute of Scientific and Technical Information of China (English)
PANG Xiongqi; ZHOU Xinyuan; LIN Changsong; HUO Zhipeng; LUO Xiaorong; PANG Hong
2010-01-01
Many of the sedimentary basins in western China were formed through the superposition and compounding of at least two previously developed sedimentary basins and in general they can be termed as complex superimposed basins.The distinct differences between these basins and monotype basins are their discontinuous stratigraphic sedimentation,stratigraphic structure and stratigraphic stress-strain action over geological history.Based on the correlation of chronological age on structural sections,superimposed basins can be divided into five types in this study:(1)continuous sedimentation type superimposed basins,(2)middle and late stratigraphic superimposed basins,(3)early and late stratigraphic superimposed basins,(4)early and middle stratigraphic superimposed basins,and(5)long-term exposed superimposed basins.Multiple source-reservoir-caprock assemblages have developed in such basins.In addition,multi-stage hydrocarbon generation and expulsion,multiple sources,polycyclic hydrocarbon accumulation and multiple-type hydrocarbon reservoirs adjustment,reformation and destruction have occurred in these basins.The complex reservoirs that have been discovered widely in the superimposed basins to date have remarkably different geologic features from primary reservoirs,and the root causes of this are folding,denudation and the fracture effect caused by multiphase tectonic events in the superimposed basins as well as associated seepage,diffusion,spilling,oxidation,degradation and cracking.Based on their genesis characteristics,complex reservoirs are divided into five categories:(1)primary reservoirs,(2)trap adjustment type reservoirs,(3)component variant reservoirs,(4)phase conversion type reservoirs and(5)scale-reformed reservoirs.
20. MPML3D: Scripting Agents for the 3D Internet.
Science.gov (United States)
Prendinger, Helmut; Ullrich, Sebastian; Nakasone, Arturo; Ishizuka, Mitsuru
2011-05-01
The aim of this paper is two-fold. First, it describes a scripting language for specifying communicative behavior and interaction of computer-controlled agents ("bots") in the popular three-dimensional (3D) multiuser online world of "Second Life" and the emerging "OpenSimulator" project. While tools for designing avatars and in-world objects in Second Life exist, technology for nonprogrammer content creators of scenarios involving scripted agents is currently missing. Therefore, we have implemented new client software that controls bots based on the Multimodal Presentation Markup Language 3D (MPML3D), a highly expressive XML-based scripting language for controlling the verbal and nonverbal behavior of interacting animated agents. Second, the paper compares Second Life and OpenSimulator platforms and discusses the merits and limitations of each from the perspective of agent control. Here, we also conducted a small study that compares the network performance of both platforms.
1. 3D-mallinnus ja 3D-animaatiot biovoimalaitoksesta
OpenAIRE
Hiltula, Tytti
2014-01-01
Opinnäytetyössä tehtiin biovoimalaitoksen piirustuksista 3D-mallinnus ja animaatiot. Työn tarkoituksena oli saada valmiiksi Recwell Oy:lle markkinointiin tarkoitetut kuva- ja videomateriaalit. Työssä perehdyttiin 3D-mallintamisen perustietoihin ja lähtökohtiin sekä animaation laatimiseen. Työ laadittiin kokonaisuudessaan AutoCAD-ohjelmalla, ja työn aikana tutustuttiin huolellisesti myös ohjelman käyttöohjeisiin. Piirustusten mitoituksessa huomattiin jo alkuvaiheessa suuria puutteita, ...
2. From 3D view to 3D print
Science.gov (United States)
Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.
2014-08-01
In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers
3. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters
Science.gov (United States)
Schild, Jonas; Seele, Sven; Masuch, Maic
2012-03-01
Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.
4. Materialedreven 3d digital formgivning
DEFF Research Database (Denmark)
Hansen, Flemming Tvede
2010-01-01
Formålet med forskningsprojektet er for det første at understøtte keramikeren i at arbejde eksperimenterende med digital formgivning, og for det andet at bidrage til en tværfaglig diskurs om brugen af digital formgivning. Forskningsprojektet fokuserer på 3d formgivning og derved på 3d digital...... formgivning og Rapid Prototyping (RP). RP er en fællesbetegnelse for en række af de teknikker, der muliggør at overføre den digitale form til 3d fysisk form. Forskningsprojektet koncentrerer sig om to overordnede forskningsspørgsmål. Det første handler om, hvordan viden og erfaring indenfor det keramiske...... fagområde kan blive udnyttet i forhold til 3d digital formgivning. Det andet handler om, hvad en sådan tilgang kan bidrage med, og hvordan den kan blive udnyttet i et dynamisk samspil med det keramiske materiale i formgivningen af 3d keramiske artefakter. Materialedreven formgivning er karakteriseret af en...
5. Novel 3D media technologies
CERN Document Server
Dagiuklas, Tasos
2015-01-01
This book describes recent innovations in 3D media and technologies, with coverage of 3D media capturing, processing, encoding, and adaptation, networking aspects for 3D Media, and quality of user experience (QoE). The contributions are based on the results of the FP7 European Project ROMEO, which focuses on new methods for the compression and delivery of 3D multi-view video and spatial audio, as well as the optimization of networking and compression jointly across the future Internet. The delivery of 3D media to individual users remains a highly challenging problem due to the large amount of data involved, diverse network characteristics and user terminal requirements, as well as the user’s context such as their preferences and location. As the number of visual views increases, current systems will struggle to meet the demanding requirements in terms of delivery of consistent video quality to fixed and mobile users. ROMEO will present hybrid networking solutions that combine the DVB-T2 and DVB-NGH broadcas...
6. 3D future internet media
CERN Document Server
Dagiuklas, Tasos
2014-01-01
This book describes recent innovations in 3D media and technologies, with coverage of 3D media capturing, processing, encoding, and adaptation, networking aspects for 3D Media, and quality of user experience (QoE). The main contributions are based on the results of the FP7 European Projects ROMEO, which focus on new methods for the compression and delivery of 3D multi-view video and spatial audio, as well as the optimization of networking and compression jointly across the Future Internet (www.ict-romeo.eu). The delivery of 3D media to individual users remains a highly challenging problem due to the large amount of data involved, diverse network characteristics and user terminal requirements, as well as the user’s context such as their preferences and location. As the number of visual views increases, current systems will struggle to meet the demanding requirements in terms of delivery of constant video quality to both fixed and mobile users. ROMEO will design and develop hybrid-networking solutions that co...
Science.gov (United States)
2002-01-01
In 1999, Genex submitted a proposal to Stennis Space Center for a volumetric 3-D display technique that would provide multiple users with a 360-degree perspective to simultaneously view and analyze 3-D data. The futuristic capabilities of the VolumeViewer(R) have offered tremendous benefits to commercial users in the fields of medicine and surgery, air traffic control, pilot training and education, computer-aided design/computer-aided manufacturing, and military/battlefield management. The technology has also helped NASA to better analyze and assess the various data collected by its satellite and spacecraft sensors. Genex capitalized on its success with Stennis by introducing two separate products to the commercial market that incorporate key elements of the 3-D display technology designed under an SBIR contract. The company Rainbow 3D(R) imaging camera is a novel, three-dimensional surface profile measurement system that can obtain a full-frame 3-D image in less than 1 second. The third product is the 360-degree OmniEye(R) video system. Ideal for intrusion detection, surveillance, and situation management, this unique camera system offers a continuous, panoramic view of a scene in real time.
8. Modification of 3D milling machine to 3D printer
OpenAIRE
Halamíček, Lukáš
2015-01-01
Tato práce se zabývá přestavbou gravírovací frézky na 3D tiskárnu. V první části se práce zabývá možnými technologiemi 3D tisku a možností jejich využití u přestavby. Dále jsou popsány a vybrány vhodné součásti pro přestavbu. V další části je realizováno řízení ohřevu podložky, trysky a řízení posuvu drátu pomocí softwaru TwinCat od společnosti Beckhoff na průmyslovém počítači. Výsledkem práce by měla být oživená 3D tiskárna. This thesis deals with rebuilding of engraving machine to 3D pri...
9. Aspects of defects in 3d-3d correspondence
Energy Technology Data Exchange (ETDEWEB)
Gang, Dongmin [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo,Chiba 277-8583 (Japan); Kim, Nakwoo [Department of Physics and Research Institute of Basic Science, Kyung Hee University,Seoul 02447 (Korea, Republic of); School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Romo, Mauricio; Yamazaki, Masahito [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo,Chiba 277-8583 (Japan); School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States)
2016-10-12
In this paper we study supersymmetric co-dimension 2 and 4 defects in the compactification of the 6d (2,0) theory of type A{sub N−1} on a 3-manifold M. The so-called 3d-3d correspondence is a relation between complexified Chern-Simons theory (with gauge group SL(N,ℂ)) on M and a 3d N=2 theory T{sub N}[M]. We study this correspondence in the presence of supersymmetric defects, which are knots/links inside the 3-manifold. Our study employs a number of different methods: state-integral models for complex Chern-Simons theory, cluster algebra techniques, domain wall theory T[SU(N)], 5d N=2 SYM, and also supergravity analysis through holography. These methods are complementary and we find agreement between them. In some cases the results lead to highly non-trivial predictions on the partition function. Our discussion includes a general expression for the cluster partition function, which can be used to compute in the presence of maximal and certain class of non-maximal punctures when N>2. We also highlight the non-Abelian description of the 3d N=2T{sub N}[M] theory with defect included, when such a description is available. This paper is a companion to our shorter paper http://dx.doi.org/10.1088/1751-8113/49/30/30LT02, which summarizes our main results.
10. Aspects of defects in 3d-3d correspondence
Science.gov (United States)
Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito
2016-10-01
In this paper we study supersymmetric co-dimension 2 and 4 defects in the compactification of the 6d (2, 0) theory of type A N -1 on a 3-manifold M . The so-called 3d-3d correspondence is a relation between complexified Chern-Simons theory (with gauge group SL(N,C) ) on M and a 3d N=2 theory T N [ M ]. We study this correspondence in the presence of supersymmetric defects, which are knots/links inside the 3-manifold. Our study employs a number of different methods: state-integral models for complex Chern-Simons theory, cluster algebra techniques, domain wall theory T [SU( N )], 5d N=2 SYM, and also supergravity analysis through holography. These methods are complementary and we find agreement between them. In some cases the results lead to highly non-trivial predictions on the partition function. Our discussion includes a general expression for the cluster partition function, which can be used to compute in the presence of maximal and certain class of non-maximal punctures when N > 2. We also highlight the non-Abelian description of the 3d N=2 T N [ M ] theory with defect included, when such a description is available. This paper is a companion to our shorter paper [1], which summarizes our main results.
11. Holography of 3d-3d correspondence at large N
Energy Technology Data Exchange (ETDEWEB)
Gang, Dongmin [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Dongdaemun-gu, Seoul, 130-722 (Korea, Republic of); Kim, Nakwoo [Department of Physics and Research Institute of Basic Science, Kyung Hee University,26 Kyungheedaero, Dongdaemun-gu, Seoul, 130-701 (Korea, Republic of); Lee, Sangmin [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Dongdaemun-gu, Seoul, 130-722 (Korea, Republic of); Center for Theoretical Physics, Department of Physics and Astronomy, College of Liberal Studies,Seoul National University, 1 Gwanakro, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)
2015-04-20
We study the physics of multiple M5-branes compactified on a hyperbolic 3-manifold. On the one hand, it leads to the 3d-3d correspondence which maps an N=2 superconformal field theory to a pure Chern-Simons theory on the 3-manifold. On the other hand, it leads to a warped AdS{sub 4} geometry in M-theory holographically dual to the superconformal field theory. Combining the holographic duality and the 3d-3d correspondence, we propose a conjecture for the large N limit of the perturbative free energy of a Chern-Simons theory on hyperbolic 3-manifold. The conjecture claims that the tree, one-loop and two-loop terms all share the same N{sup 3} scaling behavior and are proportional to the volume of the 3-manifold, while the three-loop and higher terms are suppressed at large N. Under mild assumptions, we prove the tree and one-loop parts of the conjecture. For the two-loop part, we test the conjecture numerically in a number of examples and find precise agreement. We also confirm the suppression of higher loop terms in a few examples.
12. 3D vector flow imaging
DEFF Research Database (Denmark)
Pihl, Michael Johannes
The main purpose of this PhD project is to develop an ultrasonic method for 3D vector flow imaging. The motivation is to advance the field of velocity estimation in ultrasound, which plays an important role in the clinic. The velocity of blood has components in all three spatial dimensions, yet...... conventional methods can estimate only the axial component. Several approaches for 3D vector velocity estimation have been suggested, but none of these methods have so far produced convincing in vivo results nor have they been adopted by commercial manufacturers. The basis for this project is the Transverse...... on the TO fields are suggested. They can be used to optimize the TO method. In the third part, a TO method for 3D vector velocity estimation is proposed. It employs a 2D phased array transducer and decouples the velocity estimation into three velocity components, which are estimated simultaneously based on 5...
13. Markerless 3D Face Tracking
DEFF Research Database (Denmark)
Walder, Christian; Breidt, Martin; Bulthoff, Heinrich
2009-01-01
We present a novel algorithm for the markerless tracking of deforming surfaces such as faces. We acquire a sequence of 3D scans along with color images at 40Hz. The data is then represented by implicit surface and color functions, using a novel partition-of-unity type method of efficiently...... combining local regressors using nearest neighbor searches. Both these functions act on the 4D space of 3D plus time, and use temporal information to handle the noise in individual scans. After interactive registration of a template mesh to the first frame, it is then automatically deformed to track...... the scanned surface, using the variation of both shape and color as features in a dynamic energy minimization problem. Our prototype system yields high-quality animated 3D models in correspondence, at a rate of approximately twenty seconds per timestep. Tracking results for faces and other objects...
14. 3-D Vector Flow Imaging
DEFF Research Database (Denmark)
Holbek, Simon
studies and in vivo. Phantom measurements are compared with their corresponding reference value, whereas the in vivo measurement is validated against the current golden standard for non-invasive blood velocity estimates, based on magnetic resonance imaging (MRI). The study concludes, that a high precision......, if this significant reduction in the element count can still provide precise and robust 3-D vector flow estimates in a plane. The study concludes that the RC array is capable of estimating precise 3-D vector flow both in a plane and in a volume, despite the low channel count. However, some inherent new challenges......For the last decade, the field of ultrasonic vector flow imaging has gotten an increasingly attention, as the technique offers a variety of new applications for screening and diagnostics of cardiovascular pathologies. The main purpose of this PhD project was therefore to advance the field of 3-D...
15. Microfluidic 3D Helix Mixers
Directory of Open Access Journals (Sweden)
Georgette B. Salieb-Beugelaar
2016-10-01
Full Text Available Polymeric microfluidic systems are well suited for miniaturized devices with complex functionality, and rapid prototyping methods for 3D microfluidic structures are increasingly used. Mixing at the microscale and performing chemical reactions at the microscale are important applications of such systems and we therefore explored feasibility, mixing characteristics and the ability to control a chemical reaction in helical 3D channels produced by the emerging thread template method. Mixing at the microscale is challenging because channel size reduction for improving solute diffusion comes at the price of a reduced Reynolds number that induces a strictly laminar flow regime and abolishes turbulence that would be desired for improved mixing. Microfluidic 3D helix mixers were rapidly prototyped in polydimethylsiloxane (PDMS using low-surface energy polymeric threads, twisted to form 2-channel and 3-channel helices. Structure and flow characteristics were assessed experimentally by microscopy, hydraulic measurements and chromogenic reaction, and were modeled by computational fluid dynamics. We found that helical 3D microfluidic systems produced by thread templating allow rapid prototyping, can be used for mixing and for controlled chemical reaction with two or three reaction partners at the microscale. Compared to the conventional T-shaped microfluidic system used as a control device, enhanced mixing and faster chemical reaction was found to occur due to the combination of diffusive mixing in small channels and flow folding due to the 3D helix shape. Thus, microfluidic 3D helix mixers can be rapidly prototyped using the thread template method and are an attractive and competitive method for fluid mixing and chemical reactions at the microscale.
16. 3D Printed Bionic Nanodevices.
Science.gov (United States)
Kong, Yong Lin; Gupta, Maneesh K; Johnson, Blake N; McAlpine, Michael C
2016-06-01
The ability to three-dimensionally interweave biological and functional materials could enable the creation of bionic devices possessing unique and compelling geometries, properties, and functionalities. Indeed, interfacing high performance active devices with biology could impact a variety of fields, including regenerative bioelectronic medicines, smart prosthetics, medical robotics, and human-machine interfaces. Biology, from the molecular scale of DNA and proteins, to the macroscopic scale of tissues and organs, is three-dimensional, often soft and stretchable, and temperature sensitive. This renders most biological platforms incompatible with the fabrication and materials processing methods that have been developed and optimized for functional electronics, which are typically planar, rigid and brittle. A number of strategies have been developed to overcome these dichotomies. One particularly novel approach is the use of extrusion-based multi-material 3D printing, which is an additive manufacturing technology that offers a freeform fabrication strategy. This approach addresses the dichotomies presented above by (1) using 3D printing and imaging for customized, hierarchical, and interwoven device architectures; (2) employing nanotechnology as an enabling route for introducing high performance materials, with the potential for exhibiting properties not found in the bulk; and (3) 3D printing a range of soft and nanoscale materials to enable the integration of a diverse palette of high quality functional nanomaterials with biology. Further, 3D printing is a multi-scale platform, allowing for the incorporation of functional nanoscale inks, the printing of microscale features, and ultimately the creation of macroscale devices. This blending of 3D printing, novel nanomaterial properties, and 'living' platforms may enable next-generation bionic systems. In this review, we highlight this synergistic integration of the unique properties of nanomaterials with the
17. 3D Printed Bionic Nanodevices
Science.gov (United States)
Kong, Yong Lin; Gupta, Maneesh K.; Johnson, Blake N.; McAlpine, Michael C.
2016-01-01
Summary The ability to three-dimensionally interweave biological and functional materials could enable the creation of bionic devices possessing unique and compelling geometries, properties, and functionalities. Indeed, interfacing high performance active devices with biology could impact a variety of fields, including regenerative bioelectronic medicines, smart prosthetics, medical robotics, and human-machine interfaces. Biology, from the molecular scale of DNA and proteins, to the macroscopic scale of tissues and organs, is three-dimensional, often soft and stretchable, and temperature sensitive. This renders most biological platforms incompatible with the fabrication and materials processing methods that have been developed and optimized for functional electronics, which are typically planar, rigid and brittle. A number of strategies have been developed to overcome these dichotomies. One particularly novel approach is the use of extrusion-based multi-material 3D printing, which is an additive manufacturing technology that offers a freeform fabrication strategy. This approach addresses the dichotomies presented above by (1) using 3D printing and imaging for customized, hierarchical, and interwoven device architectures; (2) employing nanotechnology as an enabling route for introducing high performance materials, with the potential for exhibiting properties not found in the bulk; and (3) 3D printing a range of soft and nanoscale materials to enable the integration of a diverse palette of high quality functional nanomaterials with biology. Further, 3D printing is a multi-scale platform, allowing for the incorporation of functional nanoscale inks, the printing of microscale features, and ultimately the creation of macroscale devices. This blending of 3D printing, novel nanomaterial properties, and ‘living’ platforms may enable next-generation bionic systems. In this review, we highlight this synergistic integration of the unique properties of nanomaterials with
18. Ideal 3D asymmetric concentrator
Energy Technology Data Exchange (ETDEWEB)
2009-01-15
Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)
19. 3D digitization of mosaics
Directory of Open Access Journals (Sweden)
Anna Maria Manferdini
2012-11-01
Full Text Available In this paper we present a methodology developed to access to Cultural Heritage information using digital 3d reality-based models as graphic interfaces. The case studies presented belong to the wide repertoire of mosaics of Ravenna. One of the most peculiar characteristics of mosaics that often limits their digital survey is their multi-scale complexity; nevertheless their models could be used in 3d information systems, for digital exhibitions, for reconstruction aims and to document their conservation conditions in order to conduct restoration interventions in digital environments aiming at speeding and performing more reliable evaluations.
20. PubChem3D: Biologically relevant 3-D similarity
Directory of Open Access Journals (Sweden)
Kim Sunghwan
2011-07-01
Full Text Available Abstract Background The use of 3-D similarity techniques in the analysis of biological data and virtual screening is pervasive, but what is a biologically meaningful 3-D similarity value? Can one find statistically significant separation between "active/active" and "active/inactive" spaces? These questions are explored using 734,486 biologically tested chemical structures, 1,389 biological assay data sets, and six different 3-D similarity types utilized by PubChem analysis tools. Results The similarity value distributions of 269.7 billion unique conformer pairs from 734,486 biologically tested compounds (all-against-all from PubChem were utilized to help work towards an answer to the question: what is a biologically meaningful 3-D similarity score? The average and standard deviation for the six similarity measures STST-opt, CTST-opt, ComboTST-opt, STCT-opt, CTCT-opt, and ComboTCT-opt were 0.54 ± 0.10, 0.07 ± 0.05, 0.62 ± 0.13, 0.41 ± 0.11, 0.18 ± 0.06, and 0.59 ± 0.14, respectively. Considering that this random distribution of biologically tested compounds was constructed using a single theoretical conformer per compound (the "default" conformer provided by PubChem, further study may be necessary using multiple diverse conformers per compound; however, given the breadth of the compound set, the single conformer per compound results may still apply to the case of multi-conformer per compound 3-D similarity value distributions. As such, this work is a critical step, covering a very wide corpus of chemical structures and biological assays, creating a statistical framework to build upon. The second part of this study explored the question of whether it was possible to realize a statistically meaningful 3-D similarity value separation between reputed biological assay "inactives" and "actives". Using the terminology of noninactive-noninactive (NN pairs and the noninactive-inactive (NI pairs to represent comparison of the "active/active" and
1. High resolution 3-D wavelength diversity imaging
Science.gov (United States)
Farhat, N. H.
1981-09-01
A physical optics, vector formulation of microwave imaging of perfectly conducting objects by wavelength and polarization diversity is presented. The results provide the theoretical basis for optimal data acquisition and three-dimensional tomographic image retrieval procedures. These include: (a) the selection of highly thinned (sparse) receiving array arrangements capable of collecting large amounts of information about remote scattering objects in a cost effective manner and (b) techniques for 3-D tomographic image reconstruction and display in which polarization diversity data is fully accounted for. Data acquisition employing a highly attractive AMTDR (Amplitude Modulated Target Derived Reference) technique is discussed and demonstrated by computer simulation. Equipment configuration for the implementation of the AMTDR technique is also given together with a measurement configuration for the implementation of wavelength diversity imaging in a roof experiment aimed at imaging a passing aircraft. Extension of the theory presented to 3-D tomographic imaging of passive noise emitting objects by spectrally selective far field cross-correlation measurements is also given. Finally several refinements made in our anechoic-chamber measurement system are shown to yield drastic improvement in performance and retrieved image quality.
2. Biocompatible 3D printed magnetic micro needles
KAUST Repository
Kavaldzhiev, Mincho
2017-01-30
Biocompatible functional materials play a significant role in drug delivery, tissue engineering and single cell analysis. We utilized 3D printing to produce high aspect ratio polymer resist microneedles on a silicon substrate and functionalized them by iron coating. Two-photon polymerization lithography has been used for printing cylindrical, pyramidal, and conical needles from a drop cast IP-DIP resist. Experiments with cells were conducted with cylindrical microneedles with 630 ± 15 nm in diameter with an aspect ratio of 1:10 and pitch of 12 μm. The needles have been arranged in square shaped arrays with various dimensions. The iron coating of the needles was 120 ± 15 nm thick and has isotropic magnetic behavior. The chemical composition and oxidation state were determined using energy electron loss spectroscopy, revealing a mixture of iron and Fe3O4 clusters. A biocompatibility assessment was performed through fluorescence microscopy using calcein/EthD-1 live/dead assay. The results show a very high biocompatibility of the iron coated needle arrays. This study provides a strategy to obtain electromagnetically functional microneedles that benefit from the flexibility in terms of geometry and shape of 3D printing. Potential applications are in areas like tissue engineering, single cell analysis or drug delivery.
3. Viewing galaxies in 3D
CERN Document Server
Krajnović, Davor
2016-01-01
Thanks to a technique that reveals galaxies in 3D, astronomers can now show that many galaxies have been wrongly classified. Davor Krajnovi\\'c argues that the classification scheme proposed 85 years ago by Edwin Hubble now needs to be revised.
4. 3D terahertz beam profiling
DEFF Research Database (Denmark)
Pedersen, Pernille Klarskov; Strikwerda, Andrew; Wang, Tianwu
2013-01-01
We present a characterization of THz beams generated in both a two-color air plasma and in a LiNbO3 crystal. Using a commercial THz camera, we record intensity images as a function of distance through the beam waist, from which we extract 2D beam profiles and visualize our measurements into 3D beam...
5. 3D Printing: Exploring Capabilities
Science.gov (United States)
Samuels, Kyle; Flowers, Jim
2015-01-01
As 3D printers become more affordable, schools are using them in increasing numbers. They fit well with the emphasis on product design in technology and engineering education, allowing students to create high-fidelity physical models to see and test different iterations in their product designs. They may also help students to "think in three…
6. When Art Meets 3D
Institute of Scientific and Technical Information of China (English)
2011-01-01
The presentation of the vanguard work,My Dream3D,the innovative production by the China Disabled People’s Performing Art Troupe(CDPPAT),directed by Joy Joosang Park,provided the film’s domestic premiere at Beijing’s Olympic Park onApril7.The show provided an intriguing insight not
7. 3D Printing of Metals
Directory of Open Access Journals (Sweden)
Manoj Gupta
2017-09-01
Full Text Available The potential benefits that could be derived if the science and technology of 3D printing were to be established have been the crux behind monumental efforts by governments, in most countries, that invest billions of dollars to develop this manufacturing technology.[...
8. Making Inexpensive 3-D Models
Science.gov (United States)
Manos, Harry
2016-01-01
Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…
9. 3D Printing: Exploring Capabilities
Science.gov (United States)
Samuels, Kyle; Flowers, Jim
2015-01-01
As 3D printers become more affordable, schools are using them in increasing numbers. They fit well with the emphasis on product design in technology and engineering education, allowing students to create high-fidelity physical models to see and test different iterations in their product designs. They may also help students to "think in three…
10. Fabrication of Nanostructured Poly-ε-caprolactone 3D Scaffolds for 3D Cell Culture Technology
KAUST Repository
Schipani, Rossana
2015-04-21
Tissue engineering is receiving tremendous attention due to the necessity to overcome the limitations related to injured or diseased tissues or organs. It is the perfect combination of cells and biomimetic-engineered materials. With the appropriate biochemical factors, it is possible to develop new effective bio-devices that are capable to improve or replace biological functions. Latest developments in microfabrication methods, employing mostly synthetic biomaterials, allow the production of three-dimensional (3D) scaffolds that are able to direct cell-to-cell interactions and specific cellular functions in order to drive tissue regeneration or cell transplantation. The presented work offers a rapid and efficient method of 3D scaffolds fabrication by using optical lithography and micro-molding techniques. Bioresorbable polymer poly-ε-caprolactone (PCL) was the material used thanks to its high biocompatibility and ability to naturally degrade in tissues. 3D PCL substrates show a particular combination in the designed length scale: cylindrical shaped pillars with 10μm diameter, 10μm height, arranged in a hexagonal lattice with spacing of 20μm were obtained. The sidewalls of the pillars were nanostructured by attributing a 3D architecture to the scaffold. The suitability of these devices as cell culture technology supports was evaluated by plating NIH/3T3 mouse embryonic fibroblasts and human Neural Stem Cells (hNSC) on them. Scanning Electron Microscopy (SEM) analysis was carried out in order to examine the micro- and nano-patterns on the surface of the supports. In addition, after seeding of cells, SEM and immunofluorescence characterization of the fabricated systems were performed to check adhesion, growth and proliferation. It was observed that cells grow and develop healthy on the bio-polymeric devices by giving rise to well-interconnected networks. 3D PCL nano-patterned pillared scaffold therefore may have considerable potential as effective tool for
11. Priprava 3D modelov za 3D tisk
OpenAIRE
2015-01-01
Po mnenju nekaterih strokovnjakov bo aditivna proizvodnja (ali 3D tiskanje) spremenila proizvodnjo industrijo, saj si bo vsak posameznik lahko natisnil svoj objekt po želji. V diplomski nalogi so predstavljene nekatere tehnologije aditivne proizvodnje. V nadaljevanju diplomske naloge je predstavljena izdelava makete hiše v merilu 1:100, vse od modeliranja do tiskanja. Poseben poudarek je posvečen predelavi modela, da je primeren za tiskanje, kjer je razvit pristop za hitrejše i...
12. Post processing of 3D models for 3D printing
OpenAIRE
2015-01-01
According to the opinion of some experts the additive manufacturing or 3D printing will change manufacturing industry, because any individual could print their own model according to his or her wishes. In this graduation thesis some of the additive manufacturing technologies are presented. Furthermore in the production of house scale model in 1:100 is presented, starting from modeling to printing. Special attention is given to postprocessing of the building model elements us...
13. 3D Printable Graphene Composite.
Science.gov (United States)
Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong
2015-07-08
In human being's history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today's personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite's linear thermal coefficient is below 75 ppm·°C(-1) from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.
14. Forensic 3D Scene Reconstruction
Energy Technology Data Exchange (ETDEWEB)
LITTLE,CHARLES Q.; PETERS,RALPH R.; RIGDON,J. BRIAN; SMALL,DANIEL E.
1999-10-12
Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.
15. 3D Printed Robotic Hand
Science.gov (United States)
Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.
2013-01-01
Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was 167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes. 16. Medical 3D thermography system OpenAIRE GRUBIŠIĆ, IVAN 2011-01-01 Infrared (IR) thermography determines the surface temperature of an object or human body using thermal IR measurement camera. It is an imaging technology which is contactless and completely non-invasive. These propertiesmake IR thermography a useful method of analysis that is used in various industrial applications to detect, monitor and predict irregularities in many fields from engineering to medical and biological observations. This paper presents a conceptual model of Medical 3D Thermo... 17. 3D silicon strip detectors Energy Technology Data Exchange (ETDEWEB) Parzefall, Ulrich [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany)], E-mail: [email protected]; Bates, Richard [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Boscardin, Maurizio [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Dalla Betta, Gian-Franco [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Eckert, Simon [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Eklund, Lars; Fleta, Celeste [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Jakobs, Karl; Kuehn, Susanne [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Lozano, Manuel [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pahn, Gregor [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Parkes, Chris [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Pellegrini, Giulio [Instituto de Microelectronica de Barcelona, IMB-CNM, CSIC, Barcelona (Spain); Pennicard, David [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Piemonte, Claudio; Ronchin, Sabina [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy); Szumlak, Tomasz [University of Glasgow, Department of Physics and Astronomy, Glasgow G12 8QQ (United Kingdom); Zoboli, Andrea [INFN and Universita' di Trento, via Sommarive 14, 38050 Povo di Trento (Italy); Zorzi, Nicola [FBK-irst, Center for Materials and Microsystems, via Sommarive 18, 38050 Povo di Trento (Italy) 2009-06-01 While the Large Hadron Collider (LHC) at CERN has started operation in autumn 2008, plans for a luminosity upgrade to the Super-LHC (sLHC) have already been developed for several years. This projected luminosity increase by an order of magnitude gives rise to a challenging radiation environment for tracking detectors at the LHC experiments. Significant improvements in radiation hardness are required with respect to the LHC. Using a strawman layout for the new tracker of the ATLAS experiment as an example, silicon strip detectors (SSDs) with short strips of 2-3 cm length are foreseen to cover the region from 28 to 60 cm distance to the beam. These SSD will be exposed to radiation levels up to 10{sup 15}N{sub eq}/cm{sup 2}, which makes radiation resistance a major concern for the upgraded ATLAS tracker. Several approaches to increasing the radiation hardness of silicon detectors exist. In this article, it is proposed to combine the radiation hard 3D-design originally conceived for pixel-style applications with the benefits of the established planar technology for strip detectors by using SSDs that have regularly spaced doped columns extending into the silicon bulk under the detector strips. The first 3D SSDs to become available for testing were made in the Single Type Column (STC) design, a technological simplification of the original 3D design. With such 3D SSDs, a small number of prototype sLHC detector modules with LHC-speed front-end electronics as used in the semiconductor tracking systems of present LHC experiments were built. Modules were tested before and after irradiation to fluences of 10{sup 15}N{sub eq}/cm{sup 2}. The tests were performed with three systems: a highly focused IR-laser with 5{mu}m spot size to make position-resolved scans of the charge collection efficiency, an Sr{sup 90}{beta}-source set-up to measure the signal levels for a minimum ionizing particle (MIP), and a beam test with 180 GeV pions at CERN. This article gives a brief overview of 18. Interactive 3D Mars Visualization Science.gov (United States) Powell, Mark W. 2012-01-01 The Interactive 3D Mars Visualization system provides high-performance, immersive visualization of satellite and surface vehicle imagery of Mars. The software can be used in mission operations to provide the most accurate position information for the Mars rovers to date. When integrated into the mission data pipeline, this system allows mission planners to view the location of the rover on Mars to 0.01-meter accuracy with respect to satellite imagery, with dynamic updates to incorporate the latest position information. Given this information so early in the planning process, rover drivers are able to plan more accurate drive activities for the rover than ever before, increasing the execution of science activities significantly. Scientifically, this 3D mapping information puts all of the science analyses to date into geologic context on a daily basis instead of weeks or months, as was the norm prior to this contribution. This allows the science planners to judge the efficacy of their previously executed science observations much more efficiently, and achieve greater science return as a result. The Interactive 3D Mars surface view is a Mars terrain browsing software interface that encompasses the entire region of exploration for a Mars surface exploration mission. The view is interactive, allowing the user to pan in any direction by clicking and dragging, or to zoom in or out by scrolling the mouse or touchpad. This set currently includes tools for selecting a point of interest, and a ruler tool for displaying the distance between and positions of two points of interest. The mapping information can be harvested and shared through ubiquitous online mapping tools like Google Mars, NASA WorldWind, and Worldwide Telescope. 19. Wireless 3D Chocolate Printer Directory of Open Access Journals (Sweden) FROILAN G. DESTREZA 2014-02-01 Full Text Available This study is for the BSHRM Students of Batangas State University (BatStateU ARASOF for the researchers believe that the Wireless 3D Chocolate Printer would be helpful in their degree program especially on making creative, artistic, personalized and decorative chocolate designs. The researchers used the Prototyping model as procedural method for the successful development and implementation of the hardware and software. This method has five phases which are the following: quick plan, quick design, prototype construction, delivery and feedback and communication. This study was evaluated by the BSHRM Students and the assessment of the respondents regarding the software and hardware application are all excellent in terms of Accuracy, Effecitveness, Efficiency, Maintainability, Reliability and User-friendliness. Also, the overall level of acceptability of the design project as evaluated by the respondents is excellent. With regard to the observation about the best raw material to use in 3D printing, the chocolate is good to use as the printed material is slightly distorted,durable and very easy to prepare; the icing is also good to use as the printed material is not distorted and is very durable but consumes time to prepare; the flour is not good as the printed material is distorted, not durable but it is easy to prepare. The computation of the economic viability level of 3d printer with reference to ROI is 37.14%. The recommendation of the researchers in the design project are as follows: adding a cooling system so that the raw material will be more durable, development of a more simplified version and improving the extrusion process wherein the user do not need to stop the printing process just to replace the empty syringe with a new one. 20. Virtual 3-D Facial Reconstruction Directory of Open Access Journals (Sweden) Martin Paul Evison 2000-06-01 Full Text Available Facial reconstructions in archaeology allow empathy with people who lived in the past and enjoy considerable popularity with the public. It is a common misconception that facial reconstruction will produce an exact likeness; a resemblance is the best that can be hoped for. Research at Sheffield University is aimed at the development of a computer system for facial reconstruction that will be accurate, rapid, repeatable, accessible and flexible. This research is described and prototypical 3-D facial reconstructions are presented. Interpolation models simulating obesity, ageing and ethnic affiliation are also described. Some strengths and weaknesses in the models, and their potential for application in archaeology are discussed. 1. How 3-D Movies Work Institute of Scientific and Technical Information of China (English) 吕铁雄 2011-01-01 难度:★★★★☆词数:450 建议阅读时间:8分钟 Most people see out of two eyes. This is a basic fact of humanity,but it’s what makes possible the illusion of depth(纵深幻觉) that 3-D movies create. Human eyes are spaced about two inches apart, meaning that each eye gives the brain a slightly different perspective(透视感)on the same object. The brain then uses this variance to quickly determine an object’s distance. 2. 3-D Modelling of Megaloolithid Clutches: Insights about Nest Construction and Dinosaur Behaviour Science.gov (United States) Vila, Bernat; Jackson, Frankie D.; Fortuny, Josep; Sellés, Albert G.; Galobart, Àngel 2010-01-01 Background Megaloolithid eggs have long been associated with sauropod dinosaurs. Despite their extensive and worldwide fossil record, interpretations of egg size and shape, clutch morphology, and incubation strategy vary. The Pinyes locality in the Upper Cretaceous Tremp Formation in the southern Pyrenees, Catalonia provides new information for addressing these issues. Nine horizons containing Megaloolithus siruguei clutches are exposed near the village of Coll de Nargó. Tectonic deformation in the study area strongly influenced egg size and shape, which could potentially lead to misinterpretation of reproductive biology if 2D and 3D maps are not corrected for bed dip that results from tectonism. Methodology/Findings Detailed taphonomic study and three-dimensional modelling of fossil eggs show that intact M. siruguei clutches contained 20–28 eggs, which is substantially larger than commonly reported from Europe and India. Linear and grouped eggs occur in three superimposed levels and form an asymmetric, elongate, bowl-shaped profile in lateral view. Computed tomography data support previous interpretations that the eggs hatched within the substrate. Megaloolithid clutch sizes reported from other European and Indian localities are typically less than 15 eggs; however, these clutches often include linear or grouped eggs that resemble those of the larger Pinyes clutches and may reflect preservation of incomplete clutches. Conclusions/Significance We propose that 25 eggs represent a typical megaloolithid clutch size and smaller egg clusters that display linear or grouped egg arrangements reported at Pinyes and other localities may represent eroded remnants of larger clutches. The similarity of megaloolithid clutch morphology from localities worldwide strongly suggests common reproductive behaviour. The distinct clutch geometry at Pinyes and other localities likely resulted from the asymmetrical, inclined, and laterally compressed titanosaur pes unguals of the female 3. Positional Awareness Map 3D (PAM3D) Science.gov (United States) Hoffman, Monica; Allen, Earl L.; Yount, John W.; Norcross, April Louise 2012-01-01 The Western Aeronautical Test Range of the National Aeronautics and Space Administration s Dryden Flight Research Center needed to address the aging software and hardware of its current situational awareness display application, the Global Real-Time Interactive Map (GRIM). GRIM was initially developed in the late 1980s and executes on older PC architectures using a Linux operating system that is no longer supported. Additionally, the software is difficult to maintain due to its complexity and loss of developer knowledge. It was decided that a replacement application must be developed or acquired in the near future. The replacement must provide the functionality of the original system, the ability to monitor test flight vehicles in real-time, and add improvements such as high resolution imagery and true 3-dimensional capability. This paper will discuss the process of determining the best approach to replace GRIM, and the functionality and capabilities of the first release of the Positional Awareness Map 3D. 4. 3D Printable Graphene Composite Science.gov (United States) Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong 2015-07-01 In human being’s history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today’s personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite’s linear thermal coefficient is below 75 ppm·°C-1 from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process. 5. 3D medical thermography device Science.gov (United States) Moghadam, Peyman 2015-05-01 In this paper, a novel handheld 3D medical thermography system is introduced. The proposed system consists of a thermal-infrared camera, a color camera and a depth camera rigidly attached in close proximity and mounted on an ergonomic handle. As a practitioner holding the device smoothly moves it around the human body parts, the proposed system generates and builds up a precise 3D thermogram model by incorporating information from each new measurement in real-time. The data is acquired in motion, thus it provides multiple points of view. When processed, these multiple points of view are adaptively combined by taking into account the reliability of each individual measurement which can vary due to a variety of factors such as angle of incidence, distance between the device and the subject and environmental sensor data or other factors influencing a confidence of the thermal-infrared data when captured. Finally, several case studies are presented to support the usability and performance of the proposed system. 6. 3D Printed Bionic Ears Science.gov (United States) Mannoor, Manu S.; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A.; Soboyejo, Winston O.; Verma, Naveen; Gracias, David H.; McAlpine, Michael C. 2013-01-01 The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the precise anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097 7. 3D printed bionic ears. Science.gov (United States) Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C 2013-06-12 The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. 8. Angiosarcoma of the Eyelid With Superimposed Enterobacter Infection. Science.gov (United States) Hamill, Eric B; Agrawal, Megha; Diwan, A Hafeez; Winthrop, Kevin L; Marx, Douglas P 2016-01-01 Angiosarcoma is a rare, aggressive, malignant endothelial neoplasm with a variable clinical presentation. The authors describe a case of angiosarcoma involving the eyelid that was complicated by a superimposed Enterobacter infection. Following positive cultures for E. aerogenes and multiple biopsies suspicious but not definitive for angiosarcoma, a final biopsy was consistent with angiosarcoma. 9. Unidirectional high fiber content composites: Automatic 3D FE model generation and damage simulation DEFF Research Database (Denmark) Qing, Hai; Mishnaevsky, Leon 2009-01-01 A new method and a software code for the automatic generation of 3D micromechanical FE models of unidirectional long-fiber-reinforced composite (LFRC) with high fiber volume fraction with random fiber arrangement are presented. The fiber arrangement in the cross-section is generated through random... 10. Thermal Analysis of 3D Printed 420 Stainless Steel Science.gov (United States) Pawar, Prathamesh Vijay Additive manufacturing opens new possibilities in the manufacturing industry. 3D printing is a form of additive manufacturing. 3D printers will have a significant influence over the industrial market, with extremely positive effects in no time. The main aim of this research is to determine the effect of process parameters of Binder Jet manufactured 420 Stainless Steel (420SS) parts on thermal properties such as thermal conductivity. Different parameters, such as layer thickness, sintering time and sintering temperature were varied. A full factorial design of experiment matrix was made by varying these parameters using two levels. Testing showed that different parameters affected the properties in a different manner. Sintering time was very important property as it changed the composition and arrangement of steel and bronze powder during the sintering process. M-flex 3D metal printer by Ex-one was used to print samples of 420SS. 11. Embedding 3D models of biological specimens in PDF publications. Science.gov (United States) Ruthensteiner, Bernhard; Hess, Martin 2008-11-01 By providing two examples, the option for embedding 3D models in electronic versions of life science publications is presented. These examples, presumably representing the first such models published, are developmental stages of an evertebrate (Patella caerulea, Mollusca) and a vertebrate species (Psetta maxima, Teleostei) obtained from histological section series reconstruction processed with the software package Amira. These surface rendering models are particularly suitable for a PDF file because they can easily be transformed to a file format required and components may be conveniently combined and hierarchically arranged. All methodological steps starting from specimen preparation until embedding of resulting models in PDF files with emphasis on conversion of Amira data to the appropriate 3D file format are explained. Usability of 3D models in PDF documents is exemplified and advantages over 2D illustrations are discussed, including better explanation capabilities for spatial arrangements, higher information contents, and limiting options for disguising results by authors. Possibilities for additional applications reaching far beyond the examples presented are suggested. Problems such as long-term compatibility of file format and hardware plus software, editing and embedding of files, file size and differences in information contents between printed and electronic version will likely be overcome by technical development and increasing tendency toward electronic at the cost of printed publications. Since 3D visualization plays an increasing role in manifold disciplines of science and appropriate tools for the popular PDF format are readily available, we propose routine application of this way of illustration in electronic life science papers. 12. 3D biometrics systems and applications CERN Document Server Zhang, David 2013-01-01 Includes discussions on popular 3D imaging technologies, combines them with biometric applications, and then presents real 3D biometric systems Introduces many efficient 3D feature extraction, matching, and fusion algorithms Techniques presented have been supported by experimental results using various 3D biometric classifications 13. Accuracy testing of a new intraoral 3D camera. Science.gov (United States) Mehl, A; Ender, A; Mörmann, W; Attin, T 2009-01-01 Surveying intraoral structures by optical means has reached the stage where it is being discussed as a serious clinical alternative to conventional impression taking. Ease of handling and, more importantly, accuracy are important criteria for the clinical suitability of these systems. This article presents a new intraoral camera for the Cerec procedure. It reports on a study investigating the accuracy of this camera and its potential clinical indications. Single-tooth and quadrant images were taken with the camera and the results compared to those obtained with a reference scanner and with the previous 3D camera model. Differences were analyzed by superimposing the data records. Accuracy was higher with the new camera than with the previous model, reaching up to 19 microm in single-tooth images. Quadrant images can also be taken with sufficient accuracy (ca 35 microm) and are simple to perform in clinical practice, thanks to built-in shake detection in automatic capture mode. 14. Imaging and 3D morphological analysis of collagen fibrils. Science.gov (United States) Altendorf, H; Decencière, E; Jeulin, D; De sa Peixoto, P; Deniset-Besseau, A; Angelini, E; Mosser, G; Schanne-Klein, M-C 2012-08-01 The recent booming of multiphoton imaging of collagen fibrils by means of second harmonic generation microscopy generates the need for the development and automation of quantitative methods for image analysis. Standard approaches sequentially analyse two-dimensional (2D) slices to gain knowledge on the spatial arrangement and dimension of the fibrils, whereas the reconstructed three-dimensional (3D) image yields better information about these characteristics. In this work, a 3D analysis method is proposed for second harmonic generation images of collagen fibrils, based on a recently developed 3D fibre quantification method. This analysis uses operators from mathematical morphology. The fibril structure is scanned with a directional distance transform. Inertia moments of the directional distances yield the main fibre orientation, corresponding to the main inertia axis. The collaboration of directional distances and fibre orientation delivers a geometrical estimate of the fibre radius. The results include local maps as well as global distribution of orientation and radius of the fibrils over the 3D image. They also bring a segmentation of the image into foreground and background, as well as a classification of the foreground pixels into the preferred orientations. This accurate determination of the spatial arrangement of the fibrils within a 3D data set will be most relevant in biomedical applications. It brings the possibility to monitor remodelling of collagen tissues upon a variety of injuries and to guide tissues engineering because biomimetic 3D organizations and density are requested for better integration of implants. © 2012 The Authors Journal of Microscopy © 2012 Royal Microscopical Society. 15. Tools to Detect Delirium Superimposed on Dementia: A Systematic Review Science.gov (United States) Morandi, Alessandro; McCurley, Jessica; Vasilevskis, Eduard E.; Fick, Donna M.; Bellelli, Giuseppe; Lee, Patricia; Jackson, James C.; Shenkin, Susan D.; Trabucchi, Marco; Schnelle, John; Inouye, Sharon K.; Ely, Wesley E.; MacLullich, Alasdair 2012-01-01 Background Delirium commonly occurs in patients with dementia. Though several tools for detecting delirium exist, it is unclear which are valid in patients with delirium superimposed on dementia. Objectives Identify valid tools to diagnose delirium superimposed on dementia Design We performed a systematic review of studies of delirium tools, which explicitly included patients with dementia. Setting In-hospital patients Participants Studies were included if delirium assessment tools were validated against standard criteria, and the presence of dementia was assessed according to standard criteria that used validated instruments. Measurements PubMed, Embase, and Web of Science databases were searched for articles in English published between January 1960 and January 2012. Results Nine studies fulfilled the selection criteria. Of the total of 1569 patients, 401 had dementia, and 50 had delirium superimposed on dementia. Six delirium tools were evaluated. One studyusing the Confusion Assessment Method (CAM) with 85% patients with dementia showed a high specificity (96–100%) and moderate sensitivity (77%).Two intensive care unit studies that used the CAM for the Intensive Care Unit (CAM-ICU) ICU reported 100% sensitivity and specificity for delirium among 23 dementia patients. One study using electroencephalography reported a sensitivity of 67% and a specificity of 91% among a population with 100% prevalence of dementia. No studies examined potential effects of dementia severity or subtype upon diagnostic accuracy. Conclusions The evidence base on tools for detection of delirium superimposed on dementia is limited, although some existing tools show promise. Further studies of existing or refined tools with larger samples and more detailed characterization of dementia are now required to address the identification of delirium superimposed on dementia. PMID:23039270 16. Conducting Polymer 3D Microelectrodes Directory of Open Access Journals (Sweden) Jenny Emnéus 2010-12-01 Full Text Available Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared with electrodes coated with only metal. An electrochemical characterization of gold/polypyrrole electrodes showed exceptional electrochemical behavior and activity. PC12 cells were finally cultured on the investigated materials as a preliminary biocompatibility assessment. These results show that the described electrodes are possibly suitable for future in-vitro neurological measurements. 17. Supernova Remnant in 3-D Science.gov (United States) 2009-01-01 of the wavelength shift is related to the speed of motion, one can determine how fast the debris are moving in either direction. Because Cas A is the result of an explosion, the stellar debris is expanding radially outwards from the explosion center. Using simple geometry, the scientists were able to construct a 3-D model using all of this information. A program called 3-D Slicer modified for astronomical use by the Astronomical Medicine Project at Harvard University in Cambridge, Mass. was used to display and manipulate the 3-D model. Commercial software was then used to create the 3-D fly-through. The blue filaments defining the blast wave were not mapped using the Doppler effect because they emit a different kind of light synchrotron radiation that does not emit light at discrete wavelengths, but rather in a broad continuum. The blue filaments are only a representation of the actual filaments observed at the blast wave. This visualization shows that there are two main components to this supernova remnant: a spherical component in the outer parts of the remnant and a flattened (disk-like) component in the inner region. The spherical component consists of the outer layer of the star that exploded, probably made of helium and carbon. These layers drove a spherical blast wave into the diffuse gas surrounding the star. The flattened component that astronomers were unable to map into 3-D prior to these Spitzer observations consists of the inner layers of the star. It is made from various heavier elements, not all shown in the visualization, such as oxygen, neon, silicon, sulphur, argon and iron. High-velocity plumes, or jets, of this material are shooting out from the explosion in the plane of the disk-like component mentioned above. Plumes of silicon appear in the northeast and southwest, while those of iron are seen in the southeast and north. These jets were already known and Doppler velocity measurements have been made for these structures, but their orientation and 18. 3D Printing of Graphene Aerogels. Science.gov (United States) Zhang, Qiangqiang; Zhang, Feng; Medarametla, Sai Pradeep; Li, Hui; Zhou, Chi; Lin, Dong 2016-04-01 3D printing of a graphene aerogel with true 3D overhang structures is highlighted. The aerogel is fabricated by combining drop-on-demand 3D printing and freeze casting. The water-based GO ink is ejected and freeze-cast into designed 3D structures. The lightweight (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction. 19. Voluntary Environmental Governance Arrangements NARCIS (Netherlands) van der Heijden, J. 2012-01-01 Voluntary environmental governance arrangements have focal attention in studies on environmental policy, regulation and governance. The four major debates in the contemporary literature on voluntary environmental governance arrangements are studied. The literature falls short of sufficiently 20. Voluntary Environmental Governance Arrangements NARCIS (Netherlands) van der Heijden, J. 2012-01-01 Voluntary environmental governance arrangements have focal attention in studies on environmental policy, regulation and governance. The four major debates in the contemporary literature on voluntary environmental governance arrangements are studied. The literature falls short of sufficiently specify 1. 3D Structure of Tillage Soils Science.gov (United States) González-Torre, Iván; Losada, Juan Carlos; Falconer, Ruth; Hapca, Simona; Tarquis, Ana M. 2015-04-01 Soil structure may be defined as the spatial arrangement of soil particles, aggregates and pores. The geometry of each one of these elements, as well as their spatial arrangement, has a great influence on the transport of fluids and solutes through the soil. Fractal/Multifractal methods have been increasingly applied to quantify soil structure thanks to the advances in computer technology (Tarquis et al., 2003). There is no doubt that computed tomography (CT) has provided an alternative for observing intact soil structure. These CT techniques reduce the physical impact to sampling, providing three-dimensional (3D) information and allowing rapid scanning to study sample dynamics in near real-time (Houston et al., 2013a). However, several authors have dedicated attention to the appropriate pore-solid CT threshold (Elliot and Heck, 2007; Houston et al., 2013b) and the better method to estimate the multifractal parameters (Grau et al., 2006; Tarquis et al., 2009). The aim of the present study is to evaluate the effect of the algorithm applied in the multifractal method (box counting and box gliding) and the cube size on the calculation of generalized fractal dimensions (Dq) in grey images without applying any threshold. To this end, soil samples were extracted from different areas plowed with three tools (moldboard, chissel and plow). Soil samples for each of the tillage treatment were packed into polypropylene cylinders of 8 cm diameter and 10 cm high. These were imaged using an mSIMCT at 155keV and 25 mA. An aluminium filter (0.25 mm) was applied to reduce beam hardening and later several corrections where applied during reconstruction. References Elliot, T.R. and Heck, R.J. 2007. A comparison of 2D and 3D thresholding of CT imagery. Can. J. Soil Sci., 87(4), 405-412. Grau, J, Médez, V.; Tarquis, A.M., Saa, A. and Díaz, M.C.. 2006. Comparison of gliding box and box-counting methods in soil image analysis. Geoderma, 134, 349-359. González-Torres, Iván. Theory and 2. 中职3D MAX课程教学改革探索%Exploration on Teaching Reformation in 3D MAX Course of Vocational School Institute of Scientific and Technical Information of China (English) 陈惠坤 2012-01-01 Describes 3D MAX course in vocational schools teaching present situation and the existing problems. With animation professional 3D MAX com~e as an example, puts forward the 3D MAX curriculum teaching objectives, discusses the teaching reformation and practice in the de- sign of the teaching content and the teaching stage arrangement, the corresponding teaching methods and material selection.%阐述3D MAX课程在中职教学中的课程现状及存在的现实问题．以动漫专业3D MAX课程为例，提出相应的中职3D MAX课程教学目标，着重论述教学改革实践设计中的教学内容及教学阶段的安排，相应教学方法的使用及教材选择等。 3. 3D multiplexed immunoplasmonics microscopy Science.gov (United States) Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel 2016-07-01 Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K+ channel subunit KV1.1) on human cancer CD44+ EGFR+ KV1.1+ MDA-MB-231 cells and reference CD44- EGFR- KV1.1+ 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third, the developed 4. Factored Facade Acquisition using Symmetric Line Arrangements KAUST Repository Ceylan, Duygu 2012-05-01 We introduce a novel framework for image-based 3D reconstruction of urban buildings based on symmetry priors. Starting from image-level edges, we generate a sparse and approximate set of consistent 3D lines. These lines are then used to simultaneously detect symmetric line arrangements while refining the estimated 3D model. Operating both on 2D image data and intermediate 3D feature representations, we perform iterative feature consolidation and effective outlier pruning, thus eliminating reconstruction artifacts arising from ambiguous or wrong stereo matches. We exploit non-local coherence of symmetric elements to generate precise model reconstructions, even in the presence of a significant amount of outlier image-edges arising from reflections, shadows, outlier objects, etc. We evaluate our algorithm on several challenging test scenarios, both synthetic and real. Beyond reconstruction, the extracted symmetry patterns are useful towards interactive and intuitive model manipulations. 5. Peptide Directed 3D Assembly of Nanoparticles through Biomolecular Interaction Science.gov (United States) Kaur, Prerna The current challenge of the 'bottom up' process is the programmed self-assembly of nanoscale building blocks into complex and larger-scale superstructures with unique properties that can be integrated as components in solar cells, microelectronics, meta materials, catalysis, and sensors. Recent trends in the complexity of device design demand the fabrication of three-dimensional (3D) superstructures from multi-nanomaterial components in precise configurations. Bio mimetic assembly is an emerging technique for building hybrid materials because living organisms are efficient, inexpensive, and environmentally benign material generators, allowing low temperature fabrication. Using this approach, a novel peptide-directed nanomaterial assembly technology based on bio molecular interaction of streptavidin and biotin is presented for assembling nanomaterials with peptides for the construction of 3D peptide-inorganic superlattices with defined 3D shape. We took advantage of robust natural collagen triple-helix peptides and used them as nanowire building blocks for 3D peptide-gold nanoparticles superlattice generation. The type of 3D peptide superlattice assembly with hybrid NP building blocks described herein shows potential for the fabrication of complex functional device which demands precise long-range arrangement and periodicity of NPs. 6. 3D Printing of Organs-On-Chips. Science.gov (United States) Yi, Hee-Gyeong; Lee, Hyungseok; Cho, Dong-Woo 2017-01-25 Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM) and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms. 7. 3D Printing of Organs-On-Chips Science.gov (United States) Yi, Hee-Gyeong; Lee, Hyungseok; Cho, Dong-Woo 2017-01-01 Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM) and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms. PMID:28952489 8. 3D Printing of Organs-On-Chips Directory of Open Access Journals (Sweden) Hee-Gyeong Yi 2017-01-01 Full Text Available Organ-on-a-chip engineering aims to create artificial living organs that mimic the complex and physiological responses of real organs, in order to test drugs by precisely manipulating the cells and their microenvironments. To achieve this, the artificial organs should to be microfabricated with an extracellular matrix (ECM and various types of cells, and should recapitulate morphogenesis, cell differentiation, and functions according to the native organ. A promising strategy is 3D printing, which precisely controls the spatial distribution and layer-by-layer assembly of cells, ECMs, and other biomaterials. Owing to this unique advantage, integration of 3D printing into organ-on-a-chip engineering can facilitate the creation of micro-organs with heterogeneity, a desired 3D cellular arrangement, tissue-specific functions, or even cyclic movement within a microfluidic device. Moreover, fully 3D-printed organs-on-chips more easily incorporate other mechanical and electrical components with the chips, and can be commercialized via automated massive production. Herein, we discuss the recent advances and the potential of 3D cell-printing technology in engineering organs-on-chips, and provides the future perspectives of this technology to establish the highly reliable and useful drug-screening platforms. 9. Crowdsourcing Based 3d Modeling Science.gov (United States) Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T. 2016-06-01 Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site. 10. Vrste i tehnike 3D modeliranja OpenAIRE Bernik, Andrija 2010-01-01 Proces stvaranja 3D stvarnih ili imaginarnih objekata naziva se 3D modeliranje. Razvoj računalne tehnologije omogućuje korisniku odabir raznih metoda i tehnika kako bi se postigla optimalna učinkovitost. Odabir je vezan za klasično 3D modeliranje ili 3D skeniranje pomoću specijaliziranih programskih i sklopovskih rješenja. 3D tehnikama modeliranja korisnik može izraditi 3D model na nekoliko načina: koristi poligone, krivulje ili hibrid dviju spomenutih tehnika pod nazivom subdivizijsko modeli... 11. Kuvaus 3D-tulostamisesta hammastekniikassa OpenAIRE Munne, Mauri; Mustonen, Tuomas; Vähäjylkkä, Jaakko 2013-01-01 3D-tulostaminen kehittyy nopeasti ja yleistyy koko ajan. Tulostimien tarkkuuksien kehittyessä 3D-tulostus on ottamassa myös jalansijaa hammastekniikan alalta. Tämän opinnäytetyön tarkoituksena on kuvata 3D-tulostamisen tilaa hammastekniikassa. 3D-tulostaminen on Suomessa vielä melko harvinaista, joten opinnäytetyön tavoitteena on koota yhteen kaikki mahdollinen tieto liittyen 3D-tulostamiseen hammastekniikassa. Tavoitteena on myös 3D-tulostimen testaaminen käytännössä aina suun skannaami... 12. Shear flow analyses for polymer melt extruding under superimposed vibration Institute of Scientific and Technical Information of China (English) LIU Yue-jun; FAN Shu-hong; SHI Pu 2005-01-01 The introduction of a vibration force field has a profound influence on the polymer formation process.However, its formation mechanism has not been explored until now. With the application of experimental equipment designed by the authors named "Constant Velocity Type Dynamic Rheometer of Capillary" or (CVDRC),we were able to analyze in detail the whole extrusion process of a polymer melt. We did this after superimposing a sine vibration of small amplitude parallel to the extruding direction of the polymer melt. Then, we created a calculation model to determine the shear stress at the wall of the capillary using a superimposed vibration. We also determined the calculation steps needed to establish the afore-mentioned shear stress. Through measurement and analysis, the instantaneous entry pressure of the capillary, the pressure gradient, and the shear stress of the polymer melt within the capillary under vibration force field can be calculated. 13. Artistic creation as stimulated by superimposed versus separated visual images. Science.gov (United States) Sobel, R S; Rothenberg, A 1980-11-01 An experiment was performed to examine the role of homospatial thinking in visual art. Each of 43 university-level art students produced three drawing stimulated by pairs of slides. Subjects were randomly assigned to view the pairs either superimposed on one another or separated on the screen. Drawings were independently judged by two internationally noted artists. As predicted, drawings containing an element from each component image intermingled were higher in creative potential when stimulated by the superimposed presentation; however, when sketches from either condition did not clearly contain images from both slides, the separated image presentation yielded the more creative result. Although results favor the hypothesis in part, the overall ambiguity of the data illustrates some of the difficulties in studying creative thought processes under experimental conditions. 14. One-DOF Superimposed Rigid Origami with Multiple States OpenAIRE Xiang Liu; Gattas, Joseph M.; Yan Chen 2016-01-01 Origami-inspired engineering design is increasingly used in the development of self-folding structures. The majority of existing self-folding structures either use a bespoke crease pattern to form a single structure, or a universal crease pattern capable of forming numerous structures with multiple folding steps. This paper presents a new approach whereby multiple distinct, rigid-foldable crease patterns are superimposed in the same sheet such that kinematic independence and 1-DOF mobility of... 15. Recrystallization microstructure modelling from superimposed deformed microstructure on microstructure model Indian Academy of Sciences (India) Prantik Mukhopadhyay 2009-08-01 The recovered cold rolled microstructure obtained from orientation image microstructure of Al–4%Mg–0.5%Mn alloy (AA5182 alloy) was superimposed on the grid of cellular automata based microstructure model. The Taylor factors of deformed/cold rolled orientations were considered as the driving force for recrystallization. The local development of recrystallized microstructure and texture were simulated with orientation dependent grain boundary mobility and compared with the experimental results. 16. 3D-Printing of Arteriovenous Malformations for Radiosurgical Treatment: Pushing Anatomy Understanding to Real Boundaries. Science.gov (United States) Conti, Alfredo; Pontoriero, Antonio; Iatì, Giuseppe; Marino, Daniele; La Torre, Domenico; Vinci, Sergio; Germanò, Antonino; Pergolizzi, Stefano; Tomasello, Francesco 2016-04-29 Radiosurgery of arteriovenous malformations (AVMs) is a challenging procedure. Accuracy of target volume contouring is one major issue to achieve AVM obliteration while avoiding disastrous complications due to suboptimal treatment. We describe a technique to improve the understanding of the complex AVM angioarchitecture by 3D prototyping of individual lesions. Arteriovenous malformations of ten patients were prototyped by 3D printing using 3D rotational angiography (3DRA) as a template. A target volume was obtained using the 3DRA; a second volume was obtained, without awareness of the first volume, using 3DRA and the 3D-printed model. The two volumes were superimposed and the conjoint and disjoint volumes were measured. We also calculated the time needed to perform contouring and assessed the confidence of the surgeons in the definition of the target volumes using a six-point scale. The time required for the contouring of the target lesion was shorter when the surgeons used the 3D-printed model of the AVM (p=0.001). The average volume contoured without the 3D model was 5.6 ± 3 mL whereas it was 5.2 ± 2.9 mL with the 3D-printed model (p=0.003). The 3D prototypes proved to be spatially reliable. Surgeons were absolutely confident or very confident in all cases that the volume contoured using the 3D-printed model was plausible and corresponded to the real boundaries of the lesion. The total cost for each case was 50 euros whereas the cost of the 3D printer was 1600 euros. 3D prototyping of AVMs is a simple, affordable, and spatially reliable procedure that can be beneficial for radiosurgery treatment planning. According to our preliminary data, individual prototyping of the brain circulation provides an intuitive comprehension of the 3D anatomy of the lesion that can be rapidly and reliably translated into the target volume. 17. Forward ramp in 3D Science.gov (United States) 1997-01-01 Mars Pathfinder's forward rover ramp can be seen successfully unfurled in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. This ramp was not used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. When this image was taken, Sojourner was still latched to one of the lander's petals, waiting for the command sequence that would execute its descent off of the lander's petal.The image helped Pathfinder scientists determine whether to deploy the rover using the forward or backward ramps and the nature of the first rover traverse. The metallic object at the lower left of the image is the lander's low-gain antenna. The square at the end of the ramp is one of the spacecraft's magnetic targets. Dust that accumulates on the magnetic targets will later be examined by Sojourner's Alpha Proton X-Ray Spectrometer instrument for chemical analysis. At right, a lander petal is visible.The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right 18. Sliding Adjustment for 3D Video Representation Directory of Open Access Journals (Sweden) Galpin Franck 2002-01-01 Full Text Available This paper deals with video coding of static scenes viewed by a moving camera. We propose an automatic way to encode such video sequences using several 3D models. Contrary to prior art in model-based coding where 3D models have to be known, the 3D models are automatically computed from the original video sequence. We show that several independent 3D models provide the same functionalities as one single 3D model, and avoid some drawbacks of the previous approaches. To achieve this goal we propose a novel algorithm of sliding adjustment, which ensures consistency of successive 3D models. The paper presents a method to automatically extract the set of 3D models and associate camera positions. The obtained representation can be used for reconstructing the original sequence, or virtual ones. It also enables 3D functionalities such as synthetic object insertion, lightning modification, or stereoscopic visualization. Results on real video sequences are presented. 19. An interactive multiview 3D display system Science.gov (United States) Zhang, Zhaoxing; Geng, Zheng; Zhang, Mei; Dong, Hui 2013-03-01 The progresses in 3D display systems and user interaction technologies will help more effective 3D visualization of 3D information. They yield a realistic representation of 3D objects and simplifies our understanding to the complexity of 3D objects and spatial relationship among them. In this paper, we describe an autostereoscopic multiview 3D display system with capability of real-time user interaction. Design principle of this autostereoscopic multiview 3D display system is presented, together with the details of its hardware/software architecture. A prototype is built and tested based upon multi-projectors and horizontal optical anisotropic display structure. Experimental results illustrate the effectiveness of this novel 3D display and user interaction system. 20. Will 3D printers manufacture your meals? NARCIS (Netherlands) Bommel, K.J.C. van 2013-01-01 These days, 3D printers are laying down plastics, metals, resins, and other materials in whatever configurations creative people can dream up. But when the next 3D printing revolution comes, you'll be able to eat it. 1. 3D ultrasound in fetal spina bifida. Science.gov (United States) Schramm, T; Gloning, K-P; Minderer, S; Tutschek, B 2008-12-01 3D ultrasound can be used to study the fetal spine, but skeletal mode can be inconclusive for the diagnosis of fetal spina bifida. We illustrate a diagnostic approach using 2D and 3D ultrasound and indicate possible pitfalls. 2. 3D Flash LIDAR Space Laser Project Data.gov (United States) National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business that has developed 3D Flash LIDAR systems for space and terrestrial applications. 3D Flash LIDAR is... 3. Eesti 3D jaoks kitsas / Virge Haavasalu Index Scriptorium Estoniae Haavasalu, Virge 2009-01-01 Produktsioonifirma Digitaalne Sputnik: Kaur ja Kaspar Kallas tegelevad filmide produtseerimise ning 3D digitaalkaamerate tootearendusega (Silicon Imaging LLC). Vendade Kallaste 3D-kaamerast. Kommenteerib Eesti Filmi Sihtasutuse direktor Marge Liiske 4. Will 3D printers manufacture your meals? NARCIS (Netherlands) Bommel, K.J.C. van 2013-01-01 These days, 3D printers are laying down plastics, metals, resins, and other materials in whatever configurations creative people can dream up. But when the next 3D printing revolution comes, you'll be able to eat it. 5. 3D printing of microscopic bacterial communities National Research Council Canada - National Science Library Jodi L. Connell; Eric T. Ritschdorff; Marvin Whiteley; Jason B. Shear 2013-01-01 .... Here, we describe a microscopic threedimensional (3D) printing strategy that enables multiple populations of bacteria to be organized within essentially any 3D geometry, including adjacent, nested, and free-floating... 6. 3D Scanning technology for offshore purposes DEFF Research Database (Denmark) Christoffersen, Morten Thoft 2005-01-01 New scanning technology makes for construction of precision 3D models of production plants and offshore production facilities......New scanning technology makes for construction of precision 3D models of production plants and offshore production facilities... 7. Laser Based 3D Volumetric Display System Science.gov (United States) 1993-03-01 Literature, Costa Mesa, CA July 1983. 3. "A Real Time Autostereoscopic Multiplanar 3D Display System", Rodney Don Williams, Felix Garcia, Jr., Texas...8217 .- NUMBERS LASER BASED 3D VOLUMETRIC DISPLAY SYSTEM PR: CD13 0. AUTHOR(S) PE: N/AWIU: DN303151 P. Soltan, J. Trias, W. Robinson, W. Dahlke 7...laser generated 3D volumetric images on a rotating double helix, (where the 3D displays are computer controlled for group viewing with the naked eye 8. 3D-Printed Millimeter Wave Structures Science.gov (United States) 2016-03-14 demonstrates the resolution of the printer with a 10 micron nozzle. Figure 2: Measured loss tangent of SEBS and SBS samples. 3D - Printed Millimeter... 3D printing of styrene-butadiene-styrene (SBS) and styrene ethylene/butylene-styrene (SEBS) is used to demonstrate the feasibility of 3D - printed ...Additionally, a dielectric lens is printed which improves the antenna gain of an open-ended WR-28 waveguide from 7 to 8.5 dBi. Keywords: 3D printing 9. 3D Printing and Its Urologic Applications Science.gov (United States) Soliman, Youssef; Feibus, Allison H; Baum, Neil 2015-01-01 3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology. PMID:26028997 10. Beowulf 3D: a case study Science.gov (United States) Engle, Rob 2008-02-01 This paper discusses the creative and technical challenges encountered during the production of "Beowulf 3D," director Robert Zemeckis' adaptation of the Old English epic poem and the first film to be simultaneously released in IMAX 3D and digital 3D formats. 11. Expanding Geometry Understanding with 3D Printing Science.gov (United States) Cochran, Jill A.; Cochran, Zane; Laney, Kendra; Dean, Mandi 2016-01-01 With the rise of personal desktop 3D printing, a wide spectrum of educational opportunities has become available for educators to leverage this technology in their classrooms. Until recently, the ability to create physical 3D models was well beyond the scope, skill, and budget of many schools. However, since desktop 3D printers have become readily… 12. Imaging a Sustainable Future in 3D Science.gov (United States) Schuhr, W.; Lee, J. D.; Kanngieser, E. 2012-07-01 It is the intention of this paper, to contribute to a sustainable future by providing objective object information based on 3D photography as well as promoting 3D photography not only for scientists, but also for amateurs. Due to the presentation of this article by CIPA Task Group 3 on "3D Photographs in Cultural Heritage", the presented samples are masterpieces of historic as well as of current 3D photography concentrating on cultural heritage. In addition to a report on exemplarily access to international archives of 3D photographs, samples for new 3D photographs taken with modern 3D cameras, as well as by means of a ground based high resolution XLITE staff camera and also 3D photographs taken from a captive balloon and the use of civil drone platforms are dealt with. To advise on optimum suited 3D methodology, as well as to catch new trends in 3D, an updated synoptic overview of the 3D visualization technology, even claiming completeness, has been carried out as a result of a systematic survey. In this respect, e.g., today's lasered crystals might be "early bird" products in 3D, which, due to lack in resolution, contrast and color, remember to the stage of the invention of photography. 13. 3D Printing and Its Urologic Applications. Science.gov (United States) Soliman, Youssef; Feibus, Allison H; Baum, Neil 2015-01-01 3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology. 14. Expanding Geometry Understanding with 3D Printing Science.gov (United States) Cochran, Jill A.; Cochran, Zane; Laney, Kendra; Dean, Mandi 2016-01-01 With the rise of personal desktop 3D printing, a wide spectrum of educational opportunities has become available for educators to leverage this technology in their classrooms. Until recently, the ability to create physical 3D models was well beyond the scope, skill, and budget of many schools. However, since desktop 3D printers have become readily… 15. 3D immersive and interactive learning CERN Document Server Cai, Yiyu 2014-01-01 This book reviews innovative uses of 3D for immersive and interactive learning, covering gifted programs, normal stream and special needs education. Reports on curriculum-based 3D learning in classrooms, and co-curriculum-based 3D student research projects. 16. Wafer level 3-D ICs process technology CERN Document Server Tan, Chuan Seng; Reif, L Rafael 2009-01-01 This book focuses on foundry-based process technology that enables the fabrication of 3-D ICs. The core of the book discusses the technology platform for pre-packaging wafer lever 3-D ICs. However, this book does not include a detailed discussion of 3-D ICs design and 3-D packaging. This is an edited book based on chapters contributed by various experts in the field of wafer-level 3-D ICs process technology. They are from academia, research labs and industry. 17. View-based 3-D object retrieval CERN Document Server Gao, Yue 2014-01-01 Content-based 3-D object retrieval has attracted extensive attention recently and has applications in a variety of fields, such as, computer-aided design, tele-medicine,mobile multimedia, virtual reality, and entertainment. The development of efficient and effective content-based 3-D object retrieval techniques has enabled the use of fast 3-D reconstruction and model design. Recent technical progress, such as the development of camera technologies, has made it possible to capture the views of 3-D objects. As a result, view-based 3-D object retrieval has become an essential but challenging res 18. Investigating Mobile Stereoscopic 3D Touchscreen Interaction OpenAIRE Colley, Ashley; Hakkila, Jonna; SCHOENING, Johannes; Posti, Maaret 2013-01-01 3D output is no longer limited to large screens in cinemas or living rooms. Nowadays more and more mobile devices are equipped with autostereoscopic 3D (S3D) touchscreens. As a consequence interaction with 3D content now also happens whilst users are on the move. In this paper we carried out a user study with 27 participants to assess how mobile interaction, i.e. whilst walking, with mobile S3D devices, differs from interaction with 2D mobile touchscreens. We investigate the difference in tou... 19. Case study: Beauty and the Beast 3D: benefits of 3D viewing for 2D to 3D conversion Science.gov (United States) Handy Turner, Tara 2010-02-01 From the earliest stages of the Beauty and the Beast 3D conversion project, the advantages of accurate desk-side 3D viewing was evident. While designing and testing the 2D to 3D conversion process, the engineering team at Walt Disney Animation Studios proposed a 3D viewing configuration that not only allowed artists to "compose" stereoscopic 3D but also improved efficiency by allowing artists to instantly detect which image features were essential to the stereoscopic appeal of a shot and which features had minimal or even negative impact. At a time when few commercial 3D monitors were available and few software packages provided 3D desk-side output, the team designed their own prototype devices and collaborated with vendors to create a "3D composing" workstation. This paper outlines the display technologies explored, final choices made for Beauty and the Beast 3D, wish-lists for future development and a few rules of thumb for composing compelling 2D to 3D conversions. 20. Web-based interactive visualization of 3D video mosaics using X3D standard Institute of Scientific and Technical Information of China (English) CHON Jaechoon; LEE Yang-Won; SHIBASAKI Ryosuke 2006-01-01 We present a method of 3D image mosaicing for real 3D representation of roadside buildings, and implement a Web-based interactive visualization environment for the 3D video mosaics created by 3D image mosaicing. The 3D image mosaicing technique developed in our previous work is a very powerful method for creating textured 3D-GIS data without excessive data processing like the laser or stereo system. For the Web-based open access to the 3D video mosaics, we build an interactive visualization environment using X3D, the emerging standard of Web 3D. We conduct the data preprocessing for 3D video mosaics and the X3D modeling for textured 3D data. The data preprocessing includes the conversion of each frame of 3D video mosaics into concatenated image files that can be hyperlinked on the Web. The X3D modeling handles the representation of concatenated images using necessary X3D nodes. By employing X3D as the data format for 3D image mosaics, the real 3D representation of roadside buildings is extended to the Web and mobile service systems. 1. User-centered 3D geovisualisation DEFF Research Database (Denmark) Nielsen, Anette Hougaard 2004-01-01 3D Geovisualisation is a multidisciplinary science mainly utilizing geographically related data, developing software systems for 3D visualisation and producing relevant models. In this paper the connection between geoinformation stored as 3D objects and the end user is of special interest....... In a broader perspective, the overall aim is to develop a language in 3D Geovisualisation gained through usability projects and the development of a theoretical background. A conceptual level of user-centered 3D Geovisualisation is introduced by applying a categorisation originating from Virtual Reality....... The conceptual level is used to structure and organise user-centered 3D Geovisualisation into four categories: representation, rendering, interface and interaction. The categories reflect a process of development of 3D Geovisualisation where objects can be represented verisimilar to the real world... 2. 3D laptop for defense applications Science.gov (United States) Edmondson, Richard; Chenault, David 2012-06-01 Polaris Sensor Technologies has developed numerous 3D display systems using a US Army patented approach. These displays have been developed as prototypes for handheld controllers for robotic systems and closed hatch driving, and as part of a TALON robot upgrade for 3D vision, providing depth perception for the operator for improved manipulation and hazard avoidance. In this paper we discuss the prototype rugged 3D laptop computer and its applications to defense missions. The prototype 3D laptop combines full temporal and spatial resolution display with the rugged Amrel laptop computer. The display is viewed through protective passive polarized eyewear, and allows combined 2D and 3D content. Uses include robot tele-operation with live 3D video or synthetically rendered scenery, mission planning and rehearsal, enhanced 3D data interpretation, and simulation. 3. High-Quality See-Through Surgical Guidance System Using Enhanced 3-D Autostereoscopic Augmented Reality. Science.gov (United States) Zhang, Xinran; Chen, Guowen; Liao, Hongen 2017-08-01 Precise minimally invasive surgery (MIS) has significant advantages over traditional open surgery in clinic. Although pre-/intraoperative diagnosis images can provide necessary guidance for therapy, hand-eye discoordination occurs when guidance information is displayed away from the surgical area. In this study, we introduce a real three-dimensional (3-D) see-through guidance system for precision surgery. To address the resolution and viewing angle limitation as well as the accuracy degradation problems of autostereoscopic 3-D display, we design a high quality and high accuracy 3-D integral videography (IV) medical image display method. Furthermore, a novel see-through microscopic device is proposed to assist surgeons with the superimposition of real 3-D guidance onto the surgical target is magnified by an optical visual magnifier module. Spatial resolutions of 3-D IV image in different depths have been increased 50%∼70%, viewing angles of different image sizes have been increased 9%∼19% compared with conventional IV display methods. Average accuracy of real 3-D guidance superimposed on surgical target was 0.93 mm ± 0.41 mm. Preclinical studies demonstrated that our system could provide real 3-D perception of anatomic structures inside the patient's body. The system showed potential clinical feasibility to provide intuitive and accurate in situ see-through guidance for microsurgery without restriction on observers' viewing position. Our system can effectively improve the precision and reliability of surgical guidance. It will have wider applicability in surgical planning, microscopy, and other fields. 4. FROM 3D MODEL DATA TO SEMANTICS Directory of Open Access Journals (Sweden) My Abdellah Kassimi 2012-01-01 Full Text Available The semantic-based 3D models retrieval systems have become necessary since the increase of 3D modelsdatabases. In this paper, we propose a new method for the mapping problem between 3D model data andsemantic data involved in semantic based retrieval for 3D models given by polygonal meshes. First, wefocused on extracting invariant descriptors from the 3D models and analyzing them to efficient semanticannotation and to improve the retrieval accuracy. Selected shape descriptors provide a set of termscommonly used to describe visually a set of objects using linguistic terms and are used as semanticconcept to label 3D model. Second, spatial relationship representing directional, topological anddistance relationships are used to derive other high-level semantic features and to avoid the problem ofautomatic 3D model annotation. Based on the resulting semantic annotation and spatial concepts, anontology for 3D model retrieval is constructed and other concepts can be inferred. This ontology is usedto find similar 3D models for a given query model. We adopted the query by semantic example approach,in which the annotation is performed mostly automatically. The proposed method is implemented in our3D search engine (SB3DMR, tested using the Princeton Shape Benchmark Database. 5. On arrangements of pseudohyperplanes Indian Academy of Sciences (India) PRIYAVRAT DESHPANDE 2016-08-01 To every realizable oriented matroid there corresponds an arrangement of real hyperplanes. The homeomorphism type of the complexified complement of such an arrangement is completely determined by the oriented matroid. In this paper we study arrangements of pseudohyperplanes; they correspond to non-realizable oriented matroids. These arrangements arise as a consequence of the Folkman--Lawrence topological representation theorem. We propose a generalization of the complexification process in this context. In particular we construct a space naturally associated with these pseudo-arrangements which is homeomorphic to the complexified complement in the realizable case. Further, we generalize the classical theorem of Salvetti and show that this space has the homotopy type of a cell complex defined in terms of the oriented matroid. 6. RT3D tutorials for GMS users Energy Technology Data Exchange (ETDEWEB) Clement, T.P. [Pacific Northwest National Lab., Richland, WA (United States); Jones, N.L. [Brigham Young Univ., Provo, UT (United States) 1998-02-01 RT3D (Reactive Transport in 3-Dimensions) is a computer code that solves coupled partial differential equations that describe reactive-flow and transport of multiple mobile and/or immobile species in a three dimensional saturated porous media. RT3D was developed from the single-species transport code, MT3D (DoD-1.5, 1997 version). As with MT3D, RT3D also uses the USGS groundwater flow model MODFLOW for computing spatial and temporal variations in groundwater head distribution. This report presents a set of tutorial problems that are designed to illustrate how RT3D simulations can be performed within the Department of Defense Groundwater Modeling System (GMS). GMS serves as a pre- and post-processing interface for RT3D. GMS can be used to define all the input files needed by RT3D code, and later the code can be launched from within GMS and run as a separate application. Once the RT3D simulation is completed, the solution can be imported to GMS for graphical post-processing. RT3D v1.0 supports several reaction packages that can be used for simulating different types of reactive contaminants. Each of the tutorials, described below, provides training on a different RT3D reaction package. Each reaction package has different input requirements, and the tutorials are designed to describe these differences. Furthermore, the tutorials illustrate the various options available in GMS for graphical post-processing of RT3D results. Users are strongly encouraged to complete the tutorials before attempting to use RT3D and GMS on a routine basis. 7. 3D change detection - Approaches and applications Science.gov (United States) Qin, Rongjun; Tian, Jiaojiao; Reinartz, Peter 2016-12-01 Due to the unprecedented technology development of sensors, platforms and algorithms for 3D data acquisition and generation, 3D spaceborne, airborne and close-range data, in the form of image based, Light Detection and Ranging (LiDAR) based point clouds, Digital Elevation Models (DEM) and 3D city models, become more accessible than ever before. Change detection (CD) or time-series data analysis in 3D has gained great attention due to its capability of providing volumetric dynamics to facilitate more applications and provide more accurate results. The state-of-the-art CD reviews aim to provide a comprehensive synthesis and to simplify the taxonomy of the traditional remote sensing CD techniques, which mainly sit within the boundary of 2D image/spectrum analysis, largely ignoring the particularities of 3D aspects of the data. The inclusion of 3D data for change detection (termed 3D CD), not only provides a source with different modality for analysis, but also transcends the border of traditional top-view 2D pixel/object-based analysis to highly detailed, oblique view or voxel-based geometric analysis. This paper reviews the recent developments and applications of 3D CD using remote sensing and close-range data, in support of both academia and industry researchers who seek for solutions in detecting and analyzing 3D dynamics of various objects of interest. We first describe the general considerations of 3D CD problems in different processing stages and identify CD types based on the information used, being the geometric comparison and geometric-spectral analysis. We then summarize relevant works and practices in urban, environment, ecology and civil applications, etc. Given the broad spectrum of applications and different types of 3D data, we discuss important issues in 3D CD methods. Finally, we present concluding remarks in algorithmic aspects of 3D CD. 8. Calculation of residual stresses by means of a 3D numerical weld simulation Energy Technology Data Exchange (ETDEWEB) Nicak, Tomas; Huemmer, Matthias [AREVA NP GmbH, Postfach 1109 (Germany) 2008-07-01 The numerical weld simulation has developed very fast in recent years. The problem complexity has increased from simple 2D models to full 3D models, which can describe the entire welding process more realistically. As recent research projects indicate, a quantitative assessment of the residual stresses by means of a 3D analysis is possible. The structure integrity can be assessed based on the weld simulation results superimposed with the operating load. Moreover, to support the qualification of welded components parametric studies for optimization of the residual stress distribution in the weld region can be performed. In this paper a full 3D numerical weld simulation for a man-hole drainage nozzle in a steam generator will be presented. The residual stresses are calculated by means of an uncoupled transient thermal and mechanical FE analysis. The paper will present a robust procedure allowing reasonable predictions of the residual stresses for complex structures in industrial practice. (authors) 9. 3D Systems” ‘Stuck in the Middle’ of the 3D Printer Boom? NARCIS (Netherlands) A. Hoffmann (Alan) 2014-01-01 textabstract3D Systems, the pioneer of 3D printing, predicted a future where "kids from 8 to 80" could design and print their ideas at home. By 2013, 9 years after the creation of the first working 3D printer, there were more than 30 major 3D printing companies competing for market share. 3DS and it 10. 3D-Barolo: 3D fitting tool for the kinematics of galaxies NARCIS (Netherlands) Di Teodoro, E. M.; Fraternali, F. 3D-Barolo (3D-Based Analysis of Rotating Object via Line Observations) or BBarolo is a tool for fitting 3D tilted-ring models to emission-line datacubes. BBarolo works with 3D FITS files, i.e. image arrays with two spatial and one spectral dimensions. BBarolo recovers the true rotation curve and 11. 3D Systems” ‘Stuck in the Middle’ of the 3D Printer Boom? NARCIS (Netherlands) A. Hoffmann (Alan) 2014-01-01 textabstract3D Systems, the pioneer of 3D printing, predicted a future where "kids from 8 to 80" could design and print their ideas at home. By 2013, 9 years after the creation of the first working 3D printer, there were more than 30 major 3D printing companies competing for market share. 3DS and 12. How accurate are the fusion of cone-beam CT and 3-D stereophotographic images? Directory of Open Access Journals (Sweden) Yasas S N Jayaratne Full Text Available BACKGROUND: Cone-beam Computed Tomography (CBCT and stereophotography are two of the latest imaging modalities available for three-dimensional (3-D visualization of craniofacial structures. However, CBCT provides only limited information on surface texture. This can be overcome by combining the bone images derived from CBCT with 3-D photographs. The objectives of this study were 1 to evaluate the feasibility of integrating 3-D Photos and CBCT images 2 to assess degree of error that may occur during the above processes and 3 to identify facial regions that would be most appropriate for 3-D image registration. METHODOLOGY: CBCT scans and stereophotographic images from 29 patients were used for this study. Two 3-D images corresponding to the skin and bone were extracted from the CBCT data. The 3-D photo was superimposed on the CBCT skin image using relatively immobile areas of the face as a reference. 3-D colour maps were used to assess the accuracy of superimposition were distance differences between the CBCT and 3-D photo were recorded as the signed average and the Root Mean Square (RMS error. PRINCIPAL FINDINGS: The signed average and RMS of the distance differences between the registered surfaces were -0.018 (±0.129 mm and 0.739 (±0.239 mm respectively. The most errors were found in areas surrounding the lips and the eyes, while minimal errors were noted in the forehead, root of the nose and zygoma. CONCLUSIONS: CBCT and 3-D photographic data can be successfully fused with minimal errors. When compared to RMS, the signed average was found to under-represent the registration error. The virtual 3-D composite craniofacial models permit concurrent assessment of bone and soft tissues during diagnosis and treatment planning. 13. Stability Criteria of 3D Inviscid Shears CERN Document Server Li, Y Charles 2009-01-01 The classical plane Couette flow, plane Poiseuille flow, and pipe Poiseuille flow share some universal 3D steady coherent structure in the form of "streak-roll-critical layer". As the Reynolds number approaches infinity, the steady coherent structure approaches a 3D limiting shear of the form (U(y,z), 0, 0) in velocity variables. All such 3D shears are steady states of the 3D Euler equations. This raises the importance of investigating the stability of such inviscid 3D shears in contrast to the classical Rayleigh theory of inviscid 2D shears. Several general criteria of stability for such inviscid 3D shears are derived. In the Appendix, an argument is given to show that a 2D limiting shear can only be the classical laminar shear. 14. 3D-tulostus : case Printrbot OpenAIRE Arvekari, Lassi 2013-01-01 Opinnäytetyön tavoitteena on selvittää 3D-tulostustekniikan perusteita ja 3D-tulostuksen nykytilannetta. 3D-tulostukseen sopivien mallien luomista tutkitaan ja mallin tekemiseen on etsitty toimivia ohjesääntöjä. Tärkeä osa työtä on tutkia mitä vaiheita 3D-tulostimen hankinnassa kotikäyttöön tulee vastaan. Käytännön kokeita varten opinnäytetyössä on case Printrbot, jossa on tutustuttu edulliseen 3D-tulostuslaitteeseen kokoonpanosta lähtien. Työn kuluessa selvisi että edulliset 3D-tulos... 15. Construction of Extended 3D Field of Views of the Internal Bladder Wall Surface: A Proof of Concept Science.gov (United States) Ben-Hamadou, Achraf; Daul, Christian; Soussen, Charles 2016-09-01 3D extended field of views (FOVs) of the internal bladder wall facilitate lesion diagnosis, patient follow-up and treatment traceability. In this paper, we propose a 3D image mosaicing algorithm guided by 2D cystoscopic video-image registration for obtaining textured FOV mosaics. In this feasibility study, the registration makes use of data from a 3D cystoscope prototype providing, in addition to each small FOV image, some 3D points located on the surface. This proof of concept shows that textured surfaces can be constructed with minimally modified cystoscopes. The potential of the method is demonstrated on numerical and real phantoms reproducing various surface shapes. Pig and human bladder textures are superimposed on phantoms with known shape and dimensions. These data allow for quantitative assessment of the 3D mosaicing algorithm based on the registration of images simulating bladder textures. 16. ERP system for 3D printing industry Directory of Open Access Journals (Sweden) Deaky Bogdan 2017-01-01 Full Text Available GOCREATE is an original cloud-based production management and optimization service which helps 3D printing service providers to use their resources better. The proposed Enterprise Resource Planning system can significantly increase income through improved productivity. With GOCREATE, the 3D printing service providers get a much higher production efficiency at a much lower licensing cost, to increase their competitiveness in the fast growing 3D printing market. 17. Reconhecimento de faces 3D com Kinect OpenAIRE Cardia Neto, João Baptista [UNESP 2014-01-01 For person identification, facil recognition has several advantages over other biometric traits due mostly to its high universelly, collectability, and acceptability. When dealing with 2D face images several problems arise related to pose, illumination, and facial expressions. To increase the performance of facial recognition, 3D mehtods have been proposed and developedm since working with 3D objects allow us to handle better the aforementioned problems. With 3D object, it is possible to rota... 18. Ultrasonic Sensor Based 3D Mapping & Localization Directory of Open Access Journals (Sweden) Shadman Fahim Ahmad 2016-04-01 Full Text Available This article provides a basic level introduction to 3D mapping using sonar sensors and localization. It describes the methods used to construct a low-cost autonomous robot along with the hardware and software used as well as an insight to the background of autonomous robotic 3D mapping and localization. We have also given an overview to what the future prospects of the robot may hold in 3D based mapping. 19. Ekologinen 3D-tulostettava asuste OpenAIRE Paulasaari, Laura 2014-01-01 Tämän opinnäytetyön aiheena oli ekologisuus 3D-tulostuksessa ja sen hyödynnettävyys erityisesti asustesuunnittelussa. Työn tarkoituksena oli selvittää, kuinka 3D-tulostusta voi tehdä ekologisemmin ja mitä vaihtoehtoja kuluttajalle tällä hetkellä on. Työ tehtiin Young skills –osuuskunnalle. 3D-tulostuksella on mahdollisuus antaa todella paljon tulevaisuuden tuotantomenetelmille ja se vapauttaa tuotteiden muotoilua täysin uudella tavalla. 3D-tulostuksen avulla voidaan keskittyä enemmän esim... 20. Topology Dictionary for 3D Video Understanding OpenAIRE 2012-01-01 This paper presents a novel approach that achieves 3D video understanding. 3D video consists of a stream of 3D models of subjects in motion. The acquisition of long sequences requires large storage space (2 GB for 1 min). Moreover, it is tedious to browse data sets and extract meaningful information. We propose the topology dictionary to encode and describe 3D video content. The model consists of a topology-based shape descriptor dictionary which can be generated from either extracted pattern... 1. Perspectives on Materials Science in 3D DEFF Research Database (Denmark) Juul Jensen, Dorte 2016-01-01 Materials characterization in 3D has opened a new era in materials science, which is discussed in this paper. The original motivations and visions behind the development of one of the new 3D techniques, namely the three dimensional x-ray diffraction (3DXRD) method, are presented and the route...... to its implementation is described. The present status of materials science in 3D is illustrated by examples related to recrystallization. Finally, challenges and suggestions for the future success for 3D Materials Science relating to hardware evolution, data analysis, data exchange and modeling... 2. Virtual Realization using 3D Password Directory of Open Access Journals (Sweden) A.B.Gadicha 2012-03-01 Full Text Available Current authentication systems suffer from many weaknesses. Textual passwords are commonly used; however, users do not follow their requirements. Users tend to choose meaningful words from dictionaries, which make textual passwords easy to break and vulnerable to dictionary or brute force attacks. Many available graphical passwords have a password space that is less than or equal to the textual password space. Smart cards or tokens can be stolen. Many biometric authentications have been proposed; however, users tend to resist using biometrics because of their intrusiveness and the effect on their privacy. Moreover, biometrics cannot be revoked. In this paper, we present and evaluate our contribution, i.e., the 3D password. The 3D password is a multifactor authentication scheme. To be authenticated, we present a 3D virtual environment where the user navigates and interacts with various objects. The sequence of actions and interactions toward the objects inside the 3D environment constructs the user’s 3D password. The 3D password can combine most existing authentication schemes such as textual passwords, graphical passwords, and various types of biometrics into a 3D virtual environment. The design of the 3D virtual environment and the type of objects selected determine the 3D password key space. 3. Dimensional accuracy of 3D printed vertebra Science.gov (United States) Ogden, Kent; Ordway, Nathaniel; Diallo, Dalanda; Tillapaugh-Fay, Gwen; Aslan, Can 2014-03-01 3D printer applications in the biomedical sciences and medical imaging are expanding and will have an increasing impact on the practice of medicine. Orthopedic and reconstructive surgery has been an obvious area for development of 3D printer applications as the segmentation of bony anatomy to generate printable models is relatively straightforward. There are important issues that should be addressed when using 3D printed models for applications that may affect patient care; in particular the dimensional accuracy of the printed parts needs to be high to avoid poor decisions being made prior to surgery or therapeutic procedures. In this work, the dimensional accuracy of 3D printed vertebral bodies derived from CT data for a cadaver spine is compared with direct measurements on the ex-vivo vertebra and with measurements made on the 3D rendered vertebra using commercial 3D image processing software. The vertebra was printed on a consumer grade 3D printer using an additive print process using PLA (polylactic acid) filament. Measurements were made for 15 different anatomic features of the vertebral body, including vertebral body height, endplate width and depth, pedicle height and width, and spinal canal width and depth, among others. It is shown that for the segmentation and printing process used, the results of measurements made on the 3D printed vertebral body are substantially the same as those produced by direct measurement on the vertebra and measurements made on the 3D rendered vertebra. 4. Illustrating Mathematics using 3D Printers OpenAIRE Knill, Oliver; Slavkovsky, Elizabeth 2013-01-01 3D printing technology can help to visualize proofs in mathematics. In this document we aim to illustrate how 3D printing can help to visualize concepts and mathematical proofs. As already known to educators in ancient Greece, models allow to bring mathematics closer to the public. The new 3D printing technology makes the realization of such tools more accessible than ever. This is an updated version of a paper included in book Low-Cost 3D Printing for science, education and Sustainable Devel... 5. Calibration for 3D Structured Light Measurement Institute of Scientific and Technical Information of China (English) 2007-01-01 A calibration procedure was developed for three-dimensional(3D) binocular structured light measurement systems. In virtue of a specially designed pattern, matching points in stereo images are extracted. And then sufficient 3D space points are obtained through pairs of images with the intrinsic and extrinsic parameters of each camera estimated prior and consequently some lights are calibrated by means of multi point fitting. Finally, a mathematical model is applied to interpolate and approximate all dynamic scanning lights based on geometry. The process of calibration method is successfully used in the binocular 3D measurement system based on structured lights and the 3D reconstruction results are satisfying. 6. Getting started in 3D with Maya CERN Document Server Watkins, Adam 2012-01-01 Deliver professional-level 3D content in no time with this comprehensive guide to 3D animation with Maya. With over 12 years of training experience, plus several award winning students under his belt, author Adam Watkins is the ideal mentor to get you up to speed with 3D in Maya. Using a structured and pragmatic approach Getting Started in 3D with Maya begins with basic theory of fundamental techniques, then builds on this knowledge using practical examples and projects to put your new skills to the test. Prepared so that you can learn in an organic fashion, each chapter builds on the know 7. FastScript3D - A Companion to Java 3D Science.gov (United States) Koenig, Patti 2005-01-01 FastScript3D is a computer program, written in the Java 3D(TM) programming language, that establishes an alternative language that helps users who lack expertise in Java 3D to use Java 3D for constructing three-dimensional (3D)-appearing graphics. The FastScript3D language provides a set of simple, intuitive, one-line text-string commands for creating, controlling, and animating 3D models. The first word in a string is the name of a command; the rest of the string contains the data arguments for the command. The commands can also be used as an aid to learning Java 3D. Developers can extend the language by adding custom text-string commands. The commands can define new 3D objects or load representations of 3D objects from files in formats compatible with such other software systems as X3D. The text strings can be easily integrated into other languages. FastScript3D facilitates communication between scripting languages [which enable programming of hyper-text markup language (HTML) documents to interact with users] and Java 3D. The FastScript3D language can be extended and customized on both the scripting side and the Java 3D side. 8. Microfluidic Bioprinting of Heterogeneous 3D Tissue Constructs Using Low-Viscosity Bioink. Science.gov (United States) Colosi, Cristina; Shin, Su Ryon; Manoharan, Vijayan; Massa, Solange; Costantini, Marco; Barbetta, Andrea; Dokmeci, Mehmet Remzi; Dentini, Mariella; Khademhosseini, Ali 2016-01-27 A novel bioink and a dispensing technique for 3D tissue-engineering applications are presented. The technique incorporates a coaxial extrusion needle using a low-viscosity cell-laden bioink to produce highly defined 3D biostructures. The extrusion system is then coupled to a microfluidic device to control the bioink arrangement deposition, demonstrating the versatility of the bioprinting technique. This low-viscosity cell-responsive bioink promotes cell migration and alignment within each fiber organizing the encapsulated cells. 9. An aerial 3D printing test mission Science.gov (United States) Hirsch, Michael; McGuire, Thomas; Parsons, Michael; Leake, Skye; Straub, Jeremy 2016-05-01 This paper provides an overview of an aerial 3D printing technology, its development and its testing. This technology is potentially useful in its own right. In addition, this work advances the development of a related in-space 3D printing technology. A series of aerial 3D printing test missions, used to test the aerial printing technology, are discussed. Through completing these test missions, the design for an in-space 3D printer may be advanced. The current design for the in-space 3D printer involves focusing thermal energy to heat an extrusion head and allow for the extrusion of molten print material. Plastics can be used as well as composites including metal, allowing for the extrusion of conductive material. A variety of experiments will be used to test this initial 3D printer design. High altitude balloons will be used to test the effects of microgravity on 3D printing, as well as parabolic flight tests. Zero pressure balloons can be used to test the effect of long 3D printing missions subjected to low temperatures. Vacuum chambers will be used to test 3D printing in a vacuum environment. The results will be used to adapt a current prototype of an in-space 3D printer. Then, a small scale prototype can be sent into low-Earth orbit as a 3-U cube satellite. With the ability to 3D print in space demonstrated, future missions can launch production hardware through which the sustainability and durability of structures in space will be greatly improved. 10. Directing Matter: Toward Atomic-Scale 3D Nanofabrication. Science.gov (United States) Jesse, Stephen; Borisevich, Albina Y; Fowlkes, Jason D; Lupini, Andrew R; Rack, Philip D; Unocic, Raymond R; Sumpter, Bobby G; Kalinin, Sergei V; Belianinov, Alex; Ovchinnikova, Olga S 2016-06-28 Enabling memristive, neuromorphic, and quantum-based computing as well as efficient mainstream energy storage and conversion technologies requires the next generation of materials customized at the atomic scale. This requires full control of atomic arrangement and bonding in three dimensions. The last two decades witnessed substantial industrial, academic, and government research efforts directed toward this goal through various lithographies and scanning-probe-based methods. These technologies emphasize 2D surface structures, with some limited 3D capability. Recently, a range of focused electron- and ion-based methods have demonstrated compelling alternative pathways to achieving atomically precise manufacturing of 3D structures in solids, liquids, and at interfaces. Electron and ion microscopies offer a platform that can simultaneously observe dynamic and static structures at the nano- and atomic scales and also induce structural rearrangements and chemical transformation. The addition of predictive modeling or rapid image analytics and feedback enables guiding these in a controlled manner. Here, we review the recent results that used focused electron and ion beams to create free-standing nanoscale 3D structures, radiolysis, and the fabrication potential with liquid precursors, epitaxial crystallization of amorphous oxides with atomic layer precision, as well as visualization and control of individual dopant motion within a 3D crystal lattice. These works lay the foundation for approaches to directing nanoscale level architectures and offer a potential roadmap to full 3D atomic control in materials. In this paper, we lay out the gaps that currently constrain the processing range of these platforms, reflect on indirect requirements, such as the integration of large-scale data analysis with theory, and discuss future prospects of these technologies. 11. Optical Arrangement and Method DEFF Research Database (Denmark) 2010-01-01 Processing of electromagnetic radiation is described, said incoming electromagnetic radiation comprising radiation in a first wavelength interval and a plurality of spatial frequencies. An arrangement comprises a focusing arrangement for focusing the incoming electromagnetic radiation, a first...... cavity configured to comprise an intra cavity laser beam, a nonlinear crystal arranged in the first cavity such that it is capable of receiving the focused electromagnetic radiation and, in dependence on the spatial overlap between the focused electromagnetic radiation and the intra-cavity laser beam......, by interaction with the intra-cavity laser beam provide processed electromagnetic radiation, said processed electromagnetic radiation comprising radiation in a second wavelength interval and at least a subset of said plurality of spatial frequencies. In other words, such an arrangement is capable of enabling... 12. The Modelling of Stereoscopic 3D Scene Acquisition Directory of Open Access Journals (Sweden) M. Hasmanda 2012-04-01 Full Text Available The main goal of this work is to find a suitable method for calculating the best setting of a stereo pair of cameras that are viewing the scene to enable spatial imaging. The method is based on a geometric model of a stereo pair cameras currently used for the acquisition of 3D scenes. Based on selectable camera parameters and object positions in the scene, the resultant model allows calculating the parameters of the stereo pair of images that influence the quality of spatial imaging. For the purpose of presenting the properties of the model of a simple 3D scene, an interactive application was created that allows, in addition to setting the cameras and scene parameters and displaying the calculated parameters, also displaying the modelled scene using perspective views and the stereo pair modelled with the aid of anaglyphic images. The resulting modelling method can be used in practice to determine appropriate parameters of the camera configuration based on the known arrangement of the objects in the scene. Analogously, it can, for a given camera configuration, determine appropriate geometrical limits of arranging the objects in the scene being displayed. This method ensures that the resulting stereoscopic recording will be of good quality and observer-friendly. 13. The 3D-city model DEFF Research Database (Denmark) Holmgren, Steen; Rüdiger, Bjarne; Tournay, Bruno 2001-01-01 We have worked with the construction and use of 3D city models for about ten years. This work has given us valuable experience concerning model methodology. In addition to this collection of knowledge, our perception of the concept of city models has changed radically. In order to explain...... of 3D city models.... 14. 3D, or Not to Be? Science.gov (United States) Norbury, Keith 2012-01-01 It may be too soon for students to be showing up for class with popcorn and gummy bears, but technology similar to that behind the 3D blockbuster movie "Avatar" is slowly finding its way into college classrooms. 3D classroom projectors are taking students on fantastic voyages inside the human body, to the ruins of ancient Greece--even to faraway… 15. User-centered 3D geovisualisation DEFF Research Database (Denmark) Nielsen, Anette Hougaard 2004-01-01 . In a broader perspective, the overall aim is to develop a language in 3D Geovisualisation gained through usability projects and the development of a theoretical background. A conceptual level of user-centered 3D Geovisualisation is introduced by applying a categorisation originating from Virtual Reality... 16. 3D Printing. What's the Harm? Science.gov (United States) Love, Tyler S.; Roy, Ken 2016-01-01 Health concerns from 3D printing were first documented by Stephens, Azimi, Orch, and Ramos (2013), who found that commercially available 3D printers were producing hazardous levels of ultrafine particles (UFPs) and volatile organic compounds (VOCs) when plastic materials were melted through the extruder. UFPs are particles less than 100 nanometers… 17. 3D Printing of Molecular Models Science.gov (United States) Gardner, Adam; Olson, Arthur 2016-01-01 Physical molecular models have played a valuable role in our understanding of the invisible nano-scale world. We discuss 3D printing and its use in producing models of the molecules of life. Complex biomolecular models, produced from 3D printed parts, can demonstrate characteristics of molecular structure and function, such as viral self-assembly,… 18. 3D printing of functional structures NARCIS (Netherlands) Krijnen, Gijsbertus J.M. 2016-01-01 The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be deve 19. 3D printing of functional structures NARCIS (Netherlands) Krijnen, Gijsbertus J.M. The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be 20. 3D Printed Block Copolymer Nanostructures Science.gov (United States) Scalfani, Vincent F.; Turner, C. Heath; Rupar, Paul A.; Jenkins, Alexander H.; Bara, Jason E. 2015-01-01 The emergence of 3D printing has dramatically advanced the availability of tangible molecular and extended solid models. Interestingly, there are few nanostructure models available both commercially and through other do-it-yourself approaches such as 3D printing. This is unfortunate given the importance of nanotechnology in science today. In this… 1. 3D elastic control for mobile devices. Science.gov (United States) Hachet, Martin; Pouderoux, Joachim; Guitton, Pascal 2008-01-01 To increase the input space of mobile devices, the authors developed a proof-of-concept 3D elastic controller that easily adapts to mobile devices. This embedded device improves the completion of high-level interaction tasks such as visualization of large documents and navigation in 3D environments. It also opens new directions for tomorrow's mobile applications. 2. Parametrizable cameras for 3D computational steering NARCIS (Netherlands) Mulder, J.D.; Wijk, J.J. van 1997-01-01 We present a method for the definition of multiple views in 3D interfaces for computational steering. The method uses the concept of a point-based parametrizable camera object. This concept enables a user to create and configure multiple views on his custom 3D interface in an intuitive graphical man 3. 3D printing of functional structures NARCIS (Netherlands) Krijnen, G.J.M. 2016-01-01 The technology colloquial known as ‘3D printing’ has developed in such diversity in printing technologies and application fields that meanwhile it seems anything is possible. However, clearly the ideal 3D Printer, with high resolution, multi-material capability, fast printing, etc. is yet to be deve 4. 3D Printed Block Copolymer Nanostructures Science.gov (United States) Scalfani, Vincent F.; Turner, C. Heath; Rupar, Paul A.; Jenkins, Alexander H.; Bara, Jason E. 2015-01-01 The emergence of 3D printing has dramatically advanced the availability of tangible molecular and extended solid models. Interestingly, there are few nanostructure models available both commercially and through other do-it-yourself approaches such as 3D printing. This is unfortunate given the importance of nanotechnology in science today. In this… 5. 3D Printing of Molecular Models Science.gov (United States) Gardner, Adam; Olson, Arthur 2016-01-01 Physical molecular models have played a valuable role in our understanding of the invisible nano-scale world. We discuss 3D printing and its use in producing models of the molecules of life. Complex biomolecular models, produced from 3D printed parts, can demonstrate characteristics of molecular structure and function, such as viral self-assembly,… 6. 3D Printing. What's the Harm? Science.gov (United States) Love, Tyler S.; Roy, Ken 2016-01-01 Health concerns from 3D printing were first documented by Stephens, Azimi, Orch, and Ramos (2013), who found that commercially available 3D printers were producing hazardous levels of ultrafine particles (UFPs) and volatile organic compounds (VOCs) when plastic materials were melted through the extruder. UFPs are particles less than 100 nanometers… 7. 3D background aerodynamics using CFD DEFF Research Database (Denmark) Sørensen, Niels N. 2002-01-01 3D rotor computations for the Greek Geovilogiki (GEO) 44 meter rotor equipped with 19 meters blades are performed. The lift and drag polars are extracted at five spanvise locations r/R= (.37, .55, .71, .82, .93) based on identification of stagnationpoints between 2D and 3D computations. The inner... 8. Topology dictionary for 3D video understanding. Science.gov (United States) Tung, Tony; Matsuyama, Takashi 2012-08-01 This paper presents a novel approach that achieves 3D video understanding. 3D video consists of a stream of 3D models of subjects in motion. The acquisition of long sequences requires large storage space (2 GB for 1 min). Moreover, it is tedious to browse data sets and extract meaningful information. We propose the topology dictionary to encode and describe 3D video content. The model consists of a topology-based shape descriptor dictionary which can be generated from either extracted patterns or training sequences. The model relies on 1) topology description and classification using Reeb graphs, and 2) a Markov motion graph to represent topology change states. We show that the use of Reeb graphs as the high-level topology descriptor is relevant. It allows the dictionary to automatically model complex sequences, whereas other strategies would require prior knowledge on the shape and topology of the captured subjects. Our approach serves to encode 3D video sequences, and can be applied for content-based description and summarization of 3D video sequences. Furthermore, topology class labeling during a learning process enables the system to perform content-based event recognition. Experiments were carried out on various 3D videos. We showcase an application for 3D video progressive summarization using the topology dictionary. 9. Integration of real-time 3D image acquisition and multiview 3D display Science.gov (United States) Zhang, Zhaoxing; Geng, Zheng; Li, Tuotuo; Li, Wei; Wang, Jingyi; Liu, Yongchun 2014-03-01 Seamless integration of 3D acquisition and 3D display systems offers enhanced experience in 3D visualization of the real world objects or scenes. The vivid representation of captured 3D objects displayed on a glasses-free 3D display screen could bring the realistic viewing experience to viewers as if they are viewing real-world scene. Although the technologies in 3D acquisition and 3D display have advanced rapidly in recent years, effort is lacking in studying the seamless integration of these two different aspects of 3D technologies. In this paper, we describe our recent progress on integrating a light-field 3D acquisition system and an autostereoscopic multiview 3D display for real-time light field capture and display. This paper focuses on both the architecture design and the implementation of the hardware and the software of this integrated 3D system. A prototype of the integrated 3D system is built to demonstrate the real-time 3D acquisition and 3D display capability of our proposed system. 10. Limited Feedback for 3D Massive MIMO under 3D-UMa and 3D-UMi Scenarios Directory of Open Access Journals (Sweden) Zheng Hu 2015-01-01 Full Text Available For three-dimensional (3D massive MIMO utilizing the uniform rectangular array (URA in the base station (BS, we propose a limited feedback transmission scheme in which the channel state information (CSI feedback operations for horizontal domain and vertical domain are separate. Compared to the traditional feedback scheme, the scheme can reduce the feedback overhead, code word index search complexity, and storage requirement. Also, based on the zenith of departure angle (ZoD distribution in 3D-Urban Macro Cell (3D-UMa and 3D-Urban Micro Cell (3D-UMi scenarios, we propose the angle quantization codebook for vertical domain, while the codebook of long term evolution-advanced (LTE-Advanced is still adopted in horizontal domain to preserve compatibility with the LTE-Advanced. Based on the angle quantization codebook, the subsampled 3-bit DFT codebook is designed for vertical domain. The system-level simulation results reveal that, to compromise the feedback overhead and system performance, 2-bit codebook for 3D-UMa scenario and 3-bit codebook for 3D-UMi scenario can meet requirements in vertical domain. The feedback period for vertical domain can also be extended appropriately to reduce the feedback overhead. 11. 6D Interpretation of 3D Gravity Science.gov (United States) Herfray, Yannick; Krasnov, Kirill; Scarinci, Carlos 2017-02-01 We show that 3D gravity, in its pure connection formulation, admits a natural 6D interpretation. The 3D field equations for the connection are equivalent to 6D Hitchin equations for the Chern–Simons 3-form in the total space of the principal bundle over the 3-dimensional base. Turning this construction around one gets an explanation of why the pure connection formulation of 3D gravity exists. More generally, we interpret 3D gravity as the dimensional reduction of the 6D Hitchin theory. To this end, we show that any \\text{SU}(2) invariant closed 3-form in the total space of the principal \\text{SU}(2) bundle can be parametrised by a connection together with a 2-form field on the base. The dimensional reduction of the 6D Hitchin theory then gives rise to 3D gravity coupled to a topological 2-form field. 12. 6D Interpretation of 3D Gravity CERN Document Server Herfray, Yannick; Scarinci, Carlos 2016-01-01 We show that 3D gravity, in its pure connection formulation, admits a natural 6D interpretation. The 3D field equations for the connection are equivalent to 6D Hitchin equations for the Chern-Simons 3-form in the total space of the principal bundle over the 3-dimensional base. Turning this construction around one gets an explanation of why the pure connection formulation of 3D gravity exists. More generally, we interpret 3D gravity as the dimensional reduction of the 6D Hitchin theory. To this end, we show that any SU(2) invariant closed 3-form in the total space of the principal SU(2) bundle can be parametrised by a connection together with a 2-form field on the base. The dimensional reduction of the 6D Hitchin theory then gives rise to 3D gravity coupled to a topological 2-form field. 13. 2D/3D switchable displays Science.gov (United States) Dekker, T.; de Zwart, S. T.; Willemsen, O. H.; Hiddink, M. G. H.; IJzerman, W. L. 2006-02-01 A prerequisite for a wide market acceptance of 3D displays is the ability to switch between 3D and full resolution 2D. In this paper we present a robust and cost effective concept for an auto-stereoscopic switchable 2D/3D display. The display is based on an LCD panel, equipped with switchable LC-filled lenticular lenses. We will discuss 3D image quality, with the focus on display uniformity. We show that slanting the lenticulars in combination with a good lens design can minimize non-uniformities in our 20" 2D/3D monitors. Furthermore, we introduce fractional viewing systems as a very robust concept to further improve uniformity in the case slanting the lenticulars and optimizing the lens design are not sufficient. We will discuss measurements and numerical simulations of the key optical characteristics of this display. Finally, we discuss 2D image quality, the switching characteristics and the residual lens effect. 14. Density-Based 3D Shape Descriptors Directory of Open Access Journals (Sweden) Schmitt Francis 2007-01-01 Full Text Available We propose a novel probabilistic framework for the extraction of density-based 3D shape descriptors using kernel density estimation. Our descriptors are derived from the probability density functions (pdf of local surface features characterizing the 3D object geometry. Assuming that the shape of the 3D object is represented as a mesh consisting of triangles with arbitrary size and shape, we provide efficient means to approximate the moments of geometric features on a triangle basis. Our framework produces a number of 3D shape descriptors that prove to be quite discriminative in retrieval applications. We test our descriptors and compare them with several other histogram-based methods on two 3D model databases, Princeton Shape Benchmark and Sculpteur, which are fundamentally different in semantic content and mesh quality. Experimental results show that our methodology not only improves the performance of existing descriptors, but also provides a rigorous framework to advance and to test new ones. 15. Fabrication of 3D Silicon Sensors Energy Technology Data Exchange (ETDEWEB) Kok, A.; Hansen, T.E.; Hansen, T.A.; Lietaer, N.; Summanwar, A.; /SINTEF, Oslo; Kenney, C.; Hasi, J.; /SLAC; Da Via, C.; /Manchester U.; Parker, S.I.; /Hawaii U. 2012-06-06 Silicon sensors with a three-dimensional (3-D) architecture, in which the n and p electrodes penetrate through the entire substrate, have many advantages over planar silicon sensors including radiation hardness, fast time response, active edge and dual readout capabilities. The fabrication of 3D sensors is however rather complex. In recent years, there have been worldwide activities on 3D fabrication. SINTEF in collaboration with Stanford Nanofabrication Facility have successfully fabricated the original (single sided double column type) 3D detectors in two prototype runs and the third run is now on-going. This paper reports the status of this fabrication work and the resulted yield. The work of other groups such as the development of double sided 3D detectors is also briefly reported. 16. Maintaining and troubleshooting your 3D printer CERN Document Server Bell, Charles 2014-01-01 Maintaining and Troubleshooting Your 3D Printer by Charles Bell is your guide to keeping your 3D printer running through preventive maintenance, repair, and diagnosing and solving problems in 3D printing. If you've bought or built a 3D printer such as a MakerBot only to be confounded by jagged edges, corner lift, top layers that aren't solid, or any of a myriad of other problems that plague 3D printer enthusiasts, then here is the book to help you get past all that and recapture the joy of creative fabrication. The book also includes valuable tips for builders and those who want to modify the 17. Ballistic annihilation with superimposed diffusion in one dimension. Science.gov (United States) Biswas, Soham; Larralde, Hernán; Leyvraz, Francois 2016-02-01 We consider a one-dimensional system with particles having either positive or negative velocity, and these particles annihilate on contact. Diffusion is superimposed on the ballistic motion of the particle. The annihilation may represent a reaction in which the two particles yield an inert species. This model has been the subject of previous work, in which it was shown that the particle concentration decays faster than either the purely ballistic or the purely diffusive case. We report on previously unnoticed behavior for large times when only one of the two species remains, and we also unravel the underlying fractal structure present in the system. We also consider in detail the case in which the initial concentration of right-going particles is 1/2+ɛ, with ɛ≠0. It is shown that remarkably rich behavior arises, in which two crossover times are observed as ɛ→0. 18. One-DOF Superimposed Rigid Origami with Multiple States Science.gov (United States) Liu, Xiang; Gattas, Joseph M.; Chen, Yan 2016-11-01 Origami-inspired engineering design is increasingly used in the development of self-folding structures. The majority of existing self-folding structures either use a bespoke crease pattern to form a single structure, or a universal crease pattern capable of forming numerous structures with multiple folding steps. This paper presents a new approach whereby multiple distinct, rigid-foldable crease patterns are superimposed in the same sheet such that kinematic independence and 1-DOF mobility of each individual pattern is preserved. This is enabled by the cross-crease vertex, a special configuration consisting of two pairs of collinear crease lines, which is proven here by means of a kinematic analysis to contain two independent 1-DOF rigid-foldable states. This enables many new origami-inspired engineering design possibilities, with two explored in depth: the compact folding of non-flat-foldable structures and sequent folding origami that can transform between multiple states without unfolding. 19. 3D Visualization Development of SIUE Campus Science.gov (United States) Nellutla, Shravya Geographic Information Systems (GIS) has progressed from the traditional map-making to the modern technology where the information can be created, edited, managed and analyzed. Like any other models, maps are simplified representations of real world. Hence visualization plays an essential role in the applications of GIS. The use of sophisticated visualization tools and methods, especially three dimensional (3D) modeling, has been rising considerably due to the advancement of technology. There are currently many off-the-shelf technologies available in the market to build 3D GIS models. One of the objectives of this research was to examine the available ArcGIS and its extensions for 3D modeling and visualization and use them to depict a real world scenario. Furthermore, with the advent of the web, a platform for accessing and sharing spatial information on the Internet, it is possible to generate interactive online maps. Integrating Internet capacity with GIS functionality redefines the process of sharing and processing the spatial information. Enabling a 3D map online requires off-the-shelf GIS software, 3D model builders, web server, web applications and client server technologies. Such environments are either complicated or expensive because of the amount of hardware and software involved. Therefore, the second objective of this research was to investigate and develop simpler yet cost-effective 3D modeling approach that uses available ArcGIS suite products and the free 3D computer graphics software for designing 3D world scenes. Both ArcGIS Explorer and ArcGIS Online will be used to demonstrate the way of sharing and distributing 3D geographic information on the Internet. A case study of the development of 3D campus for the Southern Illinois University Edwardsville is demonstrated. 20. The psychology of the 3D experience Science.gov (United States) Janicke, Sophie H.; Ellis, Andrew 2013-03-01 With 3D televisions expected to reach 50% home saturation as early as 2016, understanding the psychological mechanisms underlying the user response to 3D technology is critical for content providers, educators and academics. Unfortunately, research examining the effects of 3D technology has not kept pace with the technology's rapid adoption, resulting in large-scale use of a technology about which very little is actually known. Recognizing this need for new research, we conducted a series of studies measuring and comparing many of the variables and processes underlying both 2D and 3D media experiences. In our first study, we found narratives within primetime dramas had the power to shift viewer attitudes in both 2D and 3D settings. However, we found no difference in persuasive power between 2D and 3D content. We contend this lack of effect was the result of poor conversion quality and the unique demands of 3D production. In our second study, we found 3D technology significantly increased enjoyment when viewing sports content, yet offered no added enjoyment when viewing a movie trailer. The enhanced enjoyment of the sports content was shown to be the result of heightened emotional arousal and attention in the 3D condition. We believe the lack of effect found for the movie trailer may be genre-related. In our final study, we found 3D technology significantly enhanced enjoyment of two video games from different genres. The added enjoyment was found to be the result of an increased sense of presence. 1. Electronically reconfigurable superimposed waveguide long-period gratings Science.gov (United States) Kulishov, Mykola; Daxhelet, Xavier; Gaidi, Mounir; Chaker, Mohamed 2002-08-01 The perturbation to the refractive index induced by a periodic electric field from two systems of interdigitated electrodes with the electrode-finger period l is analyzed for a waveguide with an electro-optically (EO) active core-cladding. It is shown that the electric field induces two superimposed transmissive refractive-index gratings with different symmetries of their cross-section distributions. One of these gratings has a constant component of an EO-induced refractive index along with its variable component with periodicity l, whereas the second grating possesses only a variable component with periodicity 2l. With the proper waveguide design, the gratings provide interaction between a guided fundamental core mode and two guided cladding modes. Through the externally applied electric potential, these gratings can be independently switched ON and OFF, or they can be activated simultaneously with electronically controlled weighting factors. Coupling coefficients of both gratings are analyzed in terms of their dependence on the electrode duty ratio and dielectric permittivities of the core and cladding. The coupled-wave equations for the superimposed gratings are written and solved. The spectral characteristics are investigated by numerical simulation. It is found that the spectral characteristics are described by a dual-dip transmission spectrum with individual electronic control of the dip depths and positions. Within the concept, a new external potential application scheme is described in which the symmetry of the cross-sectional distribution of the refractive index provides coupling only between the core mode and the cladding modes, preventing interaction of the cladding modes with each another. This simple concept opens opportunities for developing a number of tunable devices for integrated optics by use of the proposed design as a building block. 2. 3D reconstruction of multiple stained histology images Directory of Open Access Journals (Sweden) Yi Song 2013-01-01 Full Text Available Context: Three dimensional (3D tissue reconstructions from the histology images with different stains allows the spatial alignment of structural and functional elements highlighted by different stains for quantitative study of many physiological and pathological phenomena. This has significant potential to improve the understanding of the growth patterns and the spatial arrangement of diseased cells, and enhance the study of biomechanical behavior of the tissue structures towards better treatments (e.g. tissue-engineering applications. Methods: This paper evaluates three strategies for 3D reconstruction from sets of two dimensional (2D histological sections with different stains, by combining methods of 2D multi-stain registration and 3D volumetric reconstruction from same stain sections. Setting and Design: The different strategies have been evaluated on two liver specimens (80 sections in total stained with Hematoxylin and Eosin (H and E, Sirius Red, and Cytokeratin (CK 7. Results and Conclusion: A strategy of using multi-stain registration to align images of a second stain to a volume reconstructed by same-stain registration results in the lowest overall error, although an interlaced image registration approach may be more robust to poor section quality. 3. Dunes morphologies and superimposed bedforms in a cellular automaton dune model Science.gov (United States) Zhang, D.; Narteau, C.; Rozier, O.; Claudin, P. 2009-04-01 We use a new 3D cellular automaton model for bedform dynamics in which individual physical processes such as erosion, deposition and transport are implemented by nearest neighbor interactions and a time-dependent stochastic process. Simultaneously, a lattice gas cellular automaton model is used to compute the flow and quantify the bed shear stress on the topography. Local erosion rates are taken proportional to the shear stress in such a way that there is a complete feedback mechanism between flow and bedform dynamics. In the numerical simulations of dune fields, we observe the formation and the evolution of barchan, transverse, longitudinal and star dunes. For all these types of dunes, we observe the emergence of superimposed bedforms when dunes are large enough. Then, we use the same model under different initial conditions, and we perform the linear stability analysis of a flat sand bed disturbed by a small sinusoidal perturbation. Comparing the most unstable wavelength in the model with the characteristic size of secondary bedforms in nature, we determine the length and time scales of our cellular automaton model. Thus, we establish a link between discrete and continuous approaches and open new perspectives for modeling and quantification of complex patterns in dune fields. 4. Experimental demonstration of 3D accelerating beam arrays. Science.gov (United States) Yu, Xianghua; Li, Runze; Yan, Shaohui; Yao, Baoli; Gao, Peng; Han, Guoxia; Lei, Ming 2016-04-10 Accelerating beams have attracted much attention in the frontiers of optical physics and technology owing to their unique propagation dynamics of nondiffracting, self-healing, and freely accelerating along curved trajectories. Such behaviors essentially arise from the particular phase factor occurring in their spatial frequency spectrum, e.g., the cubic phase associated to the spectrum of Airy beam. In this paper, we theoretically and experimentally demonstrate a sort of accelerating beam arrays, which are composed of spatially separated accelerating beams. By superimposing kinoforms of multifocal patterns into the spatial frequency spectrum of accelerating beams, different types of beam arrays, e.g., Airy beam arrays and two-main-lobe accelerating beam arrays, are generated and measured by scanning a reflection mirror near the focal region along the optical axis. The 3D intensity patterns reconstructed from the experimental data present good agreement with the theoretical counterparts. The combination of accelerating beams with optical beam arrays proposed here may find potential applications in various fields such as optical microscopes, optical micromachining, optical trapping, and so on. 5. Digital relief generation from 3D models Science.gov (United States) Wang, Meili; Sun, Yu; Zhang, Hongming; Qian, Kun; Chang, Jian; He, Dongjian 2016-09-01 It is difficult to extend image-based relief generation to high-relief generation, as the images contain insufficient height information. To generate reliefs from three-dimensional (3D) models, it is necessary to extract the height fields from the model, but this can only generate bas-reliefs. To overcome this problem, an efficient method is proposed to generate bas-reliefs and high-reliefs directly from 3D meshes. To produce relief features that are visually appropriate, the 3D meshes are first scaled. 3D unsharp masking is used to enhance the visual features in the 3D mesh, and average smoothing and Laplacian smoothing are implemented to achieve better smoothing results. A nonlinear variable scaling scheme is then employed to generate the final bas-reliefs and high-reliefs. Using the proposed method, relief models can be generated from arbitrary viewing positions with different gestures and combinations of multiple 3D models. The generated relief models can be printed by 3D printers. The proposed method provides a means of generating both high-reliefs and bas-reliefs in an efficient and effective way under the appropriate scaling factors. 6. 3D imaging in forensic odontology. Science.gov (United States) Evans, Sam; Jones, Carl; Plassmann, Peter 2010-06-16 This paper describes the investigation of a new 3D capture method for acquiring and subsequent forensic analysis of bite mark injuries on human skin. When documenting bite marks with standard 2D cameras errors in photographic technique can occur if best practice is not followed. Subsequent forensic analysis of the mark is problematic when a 3D structure is recorded into a 2D space. Although strict guidelines (BAFO) exist, these are time-consuming to follow and, due to their complexity, may produce errors. A 3D image capture and processing system might avoid the problems resulting from the 2D reduction process, simplifying the guidelines and reducing errors. Proposed Solution: a series of experiments are described in this paper to demonstrate that the potential of a 3D system might produce suitable results. The experiments tested precision and accuracy of the traditional 2D and 3D methods. A 3D image capture device minimises the amount of angular distortion, therefore such a system has the potential to create more robust forensic evidence for use in courts. A first set of experiments tested and demonstrated which method of forensic analysis creates the least amount of intra-operator error. A second set tested and demonstrated which method of image capture creates the least amount of inter-operator error and visual distortion. In a third set the effects of angular distortion on 2D and 3D methods of image capture were evaluated. 7. Medical 3D Printing for the Radiologist. Science.gov (United States) Mitsouras, Dimitris; Liacouras, Peter; Imanzadeh, Amir; Giannopoulos, Andreas A; Cai, Tianrun; Kumamaru, Kanako K; George, Elizabeth; Wake, Nicole; Caterson, Edward J; Pomahac, Bohdan; Ho, Vincent B; Grant, Gerald T; Rybicki, Frank J 2015-01-01 While use of advanced visualization in radiology is instrumental in diagnosis and communication with referring clinicians, there is an unmet need to render Digital Imaging and Communications in Medicine (DICOM) images as three-dimensional (3D) printed models capable of providing both tactile feedback and tangible depth information about anatomic and pathologic states. Three-dimensional printed models, already entrenched in the nonmedical sciences, are rapidly being embraced in medicine as well as in the lay community. Incorporating 3D printing from images generated and interpreted by radiologists presents particular challenges, including training, materials and equipment, and guidelines. The overall costs of a 3D printing laboratory must be balanced by the clinical benefits. It is expected that the number of 3D-printed models generated from DICOM images for planning interventions and fabricating implants will grow exponentially. Radiologists should at a minimum be familiar with 3D printing as it relates to their field, including types of 3D printing technologies and materials used to create 3D-printed anatomic models, published applications of models to date, and clinical benefits in radiology. Online supplemental material is available for this article. (©)RSNA, 2015. 8. 3D Reconstruction Technique for Tomographic PIV Institute of Scientific and Technical Information of China (English) 姜楠; 包全; 杨绍琼 2015-01-01 Tomographic particle image velocimetry(Tomo-PIV) is a state-of-the-art experimental technique based on a method of optical tomography to achieve the three-dimensional(3D) reconstruction for three-dimensional three-component(3D-3C) flow velocity measurements. 3D reconstruction for Tomo-PIV is carried out herein. Meanwhile, a 3D simplified tomographic reconstruction model reduced from a 3D volume light inten-sity field with 2D projection images into a 2D Tomo-slice plane with 1D projecting lines, i.e., simplifying this 3D reconstruction into a problem of 2D Tomo-slice plane reconstruction, is applied thereafter. Two kinds of the most well-known algebraic reconstruction techniques, algebraic reconstruction technique(ART) and multiple algebraic reconstruction technique(MART), are compared as well. The principles of the two reconstruction algorithms are discussed in detail, which has been performed by a series of simulation images, yielding the corresponding recon-struction images that show different features between the ART and MART algorithm, and then their advantages and disadvantages are discussed. Further discussions are made for the standard particle image reconstruction when the background noise of the pre-initial particle image has been removed. Results show that the particle image recon-struction has been greatly improved. The MART algorithm is much better than the ART. Furthermore, the computa-tional analyses of two parameters(the particle density and the number of cameras), are performed to study their effects on the reconstruction. Lastly, the 3D volume particle field is reconstructed by using the improved algorithm based on the simplified 3D tomographic reconstruction model, which proves that the algorithm simplification is feasible and it can be applied to the reconstruction of 3D volume particle field in a Tomo-PIV system. 9. 3D monitoring and quality control using intraoral optical camera systems. Science.gov (United States) Mehl, A; Koch, R; Zaruba, M; Ender, A 2013-01-01 The quality of intraoral scanning systems is steadily improving, and they are becoming easier and more reliable to operate. This opens up possibilities for routine clinical applications. A special aspect is that overlaying (superimposing) situations recorded at different times facilitates an accurate three-dimensional difference analysis. Such difference analyses can also be used to advantage in other areas of dentistry where target/actual comparisons are required. This article presents potential indications using a newly developed software, explaining the functionality of the evaluation process and the prerequisites and limitations of 3D monitoring. 10. 3D object-oriented image analysis in 3D geophysical modelling DEFF Research Database (Denmark) Fadel, I.; van der Meijde, M.; Kerle, N. 2015-01-01 Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects......) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA......) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D... 11. The reactor dynamics code DYN3D Energy Technology Data Exchange (ETDEWEB) Kliem, Soeren; Bilodid, Yuri; Fridman, Emil; Baier, Silvio; Grahn, Alexander; Gommlich, Andre; Nikitin, Evgeny; Rohde, Ulrich [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany) 2016-05-15 The article provides an overview on the code DYN3D which is a three-dimensional core model for steady-state, dynamic and depletion calculations in reactor cores with quadratic or hexagonal fuel assembly geometry being developed by the Helmholtz-Zentrum Dresden-Rossendorf for more than 20 years. The current paper gives an overview on the basic DYN3D models and the available code couplings. The verification and validation status is shortly outlined. The paper concludes with the current developments of the DYN3D code. For more detailed information the reader is referred to the publications cited in the corresponding chapters. 12. Automatic balancing of 3D models DEFF Research Database (Denmark) Christiansen, Asger Nyman; Schmidt, Ryan; Bærentzen, Jakob Andreas 2014-01-01 3D printing technologies allow for more diverse shapes than are possible with molds and the cost of making just one single object is negligible compared to traditional production methods. However, not all shapes are suitable for 3D print. One of the remaining costs is therefore human time spent......, in these cases, we will apply a rotation of the object which only deforms the shape a little near the base. No user input is required but it is possible to specify manufacturing constraints related to specific 3D print technologies. Several models have successfully been balanced and printed using both polyjet... 13. Participation and 3D Visualization Tools DEFF Research Database (Denmark) Mullins, Michael; Jensen, Mikkel Holm; Henriksen, Sune 2004-01-01 With a departure point in a workshop held at the VR Media Lab at Aalborg University , this paper deals with aspects of public participation and the use of 3D visualisation tools. The workshop grew from a desire to involve a broad collaboration between the many actors in the city through using new...... perceptions of architectural representation in urban design where 3D visualisation techniques are used. It is the authors? general finding that, while 3D visualisation media have the potential to increase understanding of virtual space for the lay public, as well as for professionals, the lay public require... 14. Computer Modelling of 3D Geological Surface CERN Document Server Kodge, B G 2011-01-01 The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area. 15. RHOCUBE: 3D density distributions modeling code Science.gov (United States) Nikutta, Robert; Agliozzo, Claudia 2016-11-01 RHOCUBE models 3D density distributions on a discrete Cartesian grid and their integrated 2D maps. It can be used for a range of applications, including modeling the electron number density in LBV shells and computing the emission measure. The RHOCUBE Python package provides several 3D density distributions, including a powerlaw shell, truncated Gaussian shell, constant-density torus, dual cones, and spiralling helical tubes, and can accept additional distributions. RHOCUBE provides convenient methods for shifts and rotations in 3D, and if necessary, an arbitrary number of density distributions can be combined into the same model cube and the integration ∫ dz performed through the joint density field. 16. A high capacity 3D steganography algorithm. Science.gov (United States) Chao, Min-Wen; Lin, Chao-hung; Yu, Cheng-Wei; Lee, Tong-Yee 2009-01-01 In this paper, we present a very high-capacity and low-distortion 3D steganography scheme. Our steganography approach is based on a novel multilayered embedding scheme to hide secret messages in the vertices of 3D polygon models. Experimental results show that the cover model distortion is very small as the number of hiding layers ranges from 7 to 13 layers. To the best of our knowledge, this novel approach can provide much higher hiding capacity than other state-of-the-art approaches, while obeying the low distortion and security basic requirements for steganography on 3D models. 17. FUN3D Manual: 12.7 Science.gov (United States) Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; 2015-01-01 This manual describes the installation and execution of FUN3D version 12.7, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 18. Science.gov (United States) Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; 2016-01-01 This manual describes the installation and execution of FUN3D version 12.9, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 19. Science.gov (United States) Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; 2015-01-01 This manual describes the installation and execution of FUN3D version 12.8, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 20. Science.gov (United States) Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; 2017-01-01 This manual describes the installation and execution of FUN3D version 13.1, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 1. FUN3D Manual: 13.0 Science.gov (United States) Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bill; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; 2016-01-01 This manual describes the installation and execution of FUN3D version 13.0, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 2. CERN Document Server Daoudi, Mohamed; Veltkamp, Remco 2013-01-01 3D Face Modeling, Analysis and Recognition presents methodologies for analyzing shapes of facial surfaces, develops computational tools for analyzing 3D face data, and illustrates them using state-of-the-art applications. The methodologies chosen are based on efficient representations, metrics, comparisons, and classifications of features that are especially relevant in the context of 3D measurements of human faces. These frameworks have a long-term utility in face analysis, taking into account the anticipated improvements in data collection, data storage, processing speeds, and application s 3. Advanced 3D Printers for Cellular Solids Science.gov (United States) 2016-06-30 SECURITY CLASSIFICATION OF: Final Report for DURIP grant W911NF-14-1-0416 This DURIP grant has allowed for the purchase of three 3D printers ...06-2016 1-Aug-2014 31-Dec-2015 Final Report: Advanced 3D printers for Cellular Solids The views, opinions and/or findings contained in this report are...Papers published in non peer-reviewed journals: Final Report: Advanced 3D printers for Cellular Solids Report Title Final Report for DURIP grant W911NF 4. 3D Printing the ATLAS' barrel toroid CERN Document Server Goncalves, Tiago Barreiro 2016-01-01 The present report summarizes my work as part of the Summer Student Programme 2016 in the CERN IR-ECO-TSP department (International Relations – Education, Communication & Outreach – Teacher and Student Programmes). Particularly, I worked closely with the S’Cool LAB team on a science education project. This project included the 3D designing, 3D printing, and assembling of a model of the ATLAS’ barrel toroid. A detailed description of the project' development is presented and a short manual on how to use 3D printing software and hardware is attached. 5. 3D Immersive Visualization with Astrophysical Data Science.gov (United States) Kent, Brian R. 2017-01-01 We present the refinement of a new 3D immersion technique for astrophysical data visualization.Methodology to create 360 degree spherical panoramas is reviewed. The 3D software package Blender coupled with Python and the Google Spatial Media module are used together to create the final data products. Data can be viewed interactively with a mobile phone or tablet or in a web browser. The technique can apply to different kinds of astronomical data including 3D stellar and galaxy catalogs, images, and planetary maps. 6. FUN3D Manual: 12.6 Science.gov (United States) Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, William L.; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A. 2015-01-01 This manual describes the installation and execution of FUN3D version 12.6, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 7. FUN3D Manual: 12.5 Science.gov (United States) Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, William L.; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A. 2014-01-01 This manual describes the installation and execution of FUN3D version 12.5, including optional dependent packages. FUN3D is a suite of computational uid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables ecient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 8. FUN3D Manual: 12.4 Science.gov (United States) Biedron, Robert T.; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; Rumsey, Christopher L.; Thomas, James L.; Wood, William A. 2014-01-01 This manual describes the installation and execution of FUN3D version 12.4, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixedelement unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status. 9. FIT3D: Fitting optical spectra Science.gov (United States) Sánchez, S. F.; Pérez, E.; Sánchez-Blázquez, P.; González, J. J.; Rosales-Ortega, F. F.; Cano-Díaz, M.; López-Cobá, C.; Marino, R. A.; Gil de Paz, A.; Mollá, M.; López-Sánchez, A. R.; Ascasibar, Y.; Barrera-Ballesteros, J. 2016-09-01 FIT3D fits optical spectra to deblend the underlying stellar population and the ionized gas, and extract physical information from each component. FIT3D is focused on the analysis of Integral Field Spectroscopy data, but is not restricted to it, and is the basis of Pipe3D, a pipeline used in the analysis of datasets like CALIFA, MaNGA, and SAMI. It can run iteratively or in an automatic way to derive the parameters of a large set of spectra. 10. 3-D Human Modeling and Animation CERN Document Server Ratner, Peter 2012-01-01 3-D Human Modeling and Animation Third Edition All the tools and techniques you need to bring human figures to 3-D life Thanks to today's remarkable technology, artists can create and animate realistic, three-dimensional human figures that were not possible just a few years ago. This easy-to-follow book guides you through all the necessary steps to adapt your own artistic skill in figure drawing, painting, and sculpture to this exciting digital canvas. 3-D Human Modeling and Animation, Third Edition starts you off with simple modeling, then prepares you for more advanced techniques for crea 11. 3D packaging for integrated circuit systems Energy Technology Data Exchange (ETDEWEB) Chu, D.; Palmer, D.W. [eds. 1996-11-01 A goal was set for high density, high performance microelectronics pursued through a dense 3D packing of integrated circuits. A {open_quotes}tool set{close_quotes} of assembly processes have been developed that enable 3D system designs: 3D thermal analysis, silicon electrical through vias, IC thinning, mounting wells in silicon, adhesives for silicon stacking, pretesting of IC chips before commitment to stacks, and bond pad bumping. Validation of these process developments occurred through both Sandia prototypes and subsequent commercial examples. 12. Do-It-Yourself: 3D Models of Hydrogenic Orbitals through 3D Printing Science.gov (United States) Griffith, Kaitlyn M.; de Cataldo, Riccardo; Fogarty, Keir H. 2016-01-01 Introductory chemistry students often have difficulty visualizing the 3-dimensional shapes of the hydrogenic electron orbitals without the aid of physical 3D models. Unfortunately, commercially available models can be quite expensive. 3D printing offers a solution for producing models of hydrogenic orbitals. 3D printing technology is widely… 13. 3D presentatie van geluid in de cockpit [3D sound presentation in the cockpit NARCIS (Netherlands) Bronkhorst, A.W. 2003-01-01 A.W. Bronkhorst, 3D-presentatie van geluid in de cockpit 1 Using virtual acoustics, sound can be presented from virtual sources located in the 3D space around the listener. This 3D sound has interesting applications in the cockpit. Sounds can be used to convey directional information, and interferen 14. XML3D and Xflow: combining declarative 3D for the Web with generic data flows. Science.gov (United States) Klein, Felix; Sons, Kristian; Rubinstein, Dmitri; Slusallek, Philipp 2013-01-01 Researchers have combined XML3D, which provides declarative, interactive 3D scene descriptions based on HTML5, with Xflow, a language for declarative, high-performance data processing. The result lets Web developers combine a 3D scene graph with data flows for dynamic meshes, animations, image processing, and postprocessing. 15. Best connected rectangular arrangements Directory of Open Access Journals (Sweden) Krishnendra Shekhawat 2016-03-01 Full Text Available It can be found quite often in the literature that many well-known architects have employed either the golden rectangle or the Fibonacci rectangle in their works. On contrary, it is rare to find any specific reason for using them so often. Recently, Shekhawat (2015 proved that the golden rectangle and the Fibonacci rectangle are one of the best connected rectangular arrangements and this may be one of the reasons for their high presence in architectural designs. In this work we present an algorithm that generates n-4 best connected rectangular arrangements so that the proposed solutions can be further used by architects for their designs. 16. Analyses and Measures of GPR Signal with Superimposed Noise Science.gov (United States) Chicarella, Simone; Ferrara, Vincenzo; D'Atanasio, Paolo; Frezza, Fabrizio; Pajewski, Lara; Pavoncello, Settimio; Prontera, Santo; Tedeschi, Nicola; Zambotti, Alessandro 2014-05-01 The influence of EM noises and environmental hard conditions on the GPR surveys has been examined analytically [1]. In the case of pulse radar GPR, many unwanted signals as stationary clutter, non-stationary clutter, random noise, and time jitter, influence the measurement signal. When GPR is motionless, stationary clutter is the most dominant signal component due to the reflections of static objects different from the investigated target, and to the direct antenna coupling. Moving objects like e.g. persons and vehicles, and the swaying of tree crown, produce non-stationary clutter. Device internal noise and narrowband jamming are e.g. two potential sources of random noises. Finally, trigger instabilities generate random jitter. In order to estimate the effective influence of these noise signal components, we organized some experimental setup of measurement. At first, we evaluated for the case of a GPR basic detection, simpler image processing of radargram. In the future, we foresee experimental measurements for detection of the Doppler frequency changes induced by movements of targets (like physiological movements of survivors under debris). We obtain image processing of radargram by using of GSSI SIR® 2000 GPR system together with the UWB UHF GPR-antenna (SUB-ECHO HBD 300, a model manufactured by Radarteam company). Our work includes both characterization of GPR signal without (or almost without) a superimposed noise, and the effect of jamming originated from the coexistence of a different radio signal. For characterizing GPR signal, we organized a measurement setup that includes the following instruments: mod. FSP 30 spectrum analyser by Rohde & Schwarz which operates in the frequency range 9 KHz - 30 GHz, mod. Sucoflex 104 cable by Huber Suhner (10 MHz - 18 GHz), and HL050 antenna by Rohde & Schwarz (bandwidth: from 850 MHz to 26.5 GHz). The next analysis of superimposed jamming will examine two different signal sources: by a cellular phone and by a 17. Two Accelerating Techniques for 3D Reconstruction Institute of Scientific and Technical Information of China (English) 刘世霞; 胡事民; 孙家广 2002-01-01 Automatic reconstruction of 3D objects from 2D orthographic views has been a major research issue in CAD/CAM. In this paper, two accelerating techniques to improve the efficiency of reconstruction are presented. First, some pseudo elements are removed by depth and topology information as soon as the wire-frame is constructed, which reduces the searching space. Second, the proposed algorithm does not establish all possible surfaces in the process of generating 3D faces. The surfaces and edge loops are generated by using the relationship between the boundaries of 3D faces and their projections. This avoids the growth in combinational complexity of previous methods that have to check all possible pairs of 3D candidate edges. 18. Nonlaser-based 3D surface imaging Energy Technology Data Exchange (ETDEWEB) Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J. [Lawrence Livermore National Lab., CA (United States) 1994-11-15 3D surface imaging refers to methods that generate a 3D surface representation of objects of a scene under viewing. Laser-based 3D surface imaging systems are commonly used in manufacturing, robotics and biomedical research. Although laser-based systems provide satisfactory solutions for most applications, there are situations where non laser-based approaches are preferred. The issues that make alternative methods sometimes more attractive are: (1) real-time data capturing, (2) eye-safety, (3) portability, and (4) work distance. The focus of this presentation is on generating a 3D surface from multiple 2D projected images using CCD cameras, without a laser light source. Two methods are presented: stereo vision and depth-from-focus. Their applications are described. 19. Eyes on the Earth 3D Science.gov (United States) Kulikov, anton I.; Doronila, Paul R.; Nguyen, Viet T.; Jackson, Randal K.; Greene, William M.; Hussey, Kevin J.; Garcia, Christopher M.; Lopez, Christian A. 2013-01-01 Eyes on the Earth 3D software gives scientists, and the general public, a realtime, 3D interactive means of accurately viewing the real-time locations, speed, and values of recently collected data from several of NASA's Earth Observing Satellites using a standard Web browser (climate.nasa.gov/eyes). Anyone with Web access can use this software to see where the NASA fleet of these satellites is now, or where they will be up to a year in the future. The software also displays several Earth Science Data sets that have been collected on a daily basis. This application uses a third-party, 3D, realtime, interactive game engine called Unity 3D to visualize the satellites and is accessible from a Web browser. 20. 3D Flash LIDAR Space Laser Project Data.gov (United States) National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time... 1. 3D scanning particle tracking velocimetry Science.gov (United States) Hoyer, Klaus; Holzner, Markus; Lüthi, Beat; Guala, Michele; Liberzon, Alexander; Kinzelbach, Wolfgang 2005-11-01 In this article, we present an experimental setup and data processing schemes for 3D scanning particle tracking velocimetry (SPTV), which expands on the classical 3D particle tracking velocimetry (PTV) through changes in the illumination, image acquisition and analysis. 3D PTV is a flexible flow measurement technique based on the processing of stereoscopic images of flow tracer particles. The technique allows obtaining Lagrangian flow information directly from measured 3D trajectories of individual particles. While for a classical PTV the entire region of interest is simultaneously illuminated and recorded, in SPTV the flow field is recorded by sequential tomographic high-speed imaging of the region of interest. The advantage of the presented method is a considerable increase in maximum feasible seeding density. Results are shown for an experiment in homogenous turbulence and compared with PTV. SPTV yielded an average 3,500 tracked particles per time step, which implies a significant enhancement of the spatial resolution for Lagrangian flow measurements. 2. 3D-printed bioanalytical devices Science.gov (United States) Bishop, Gregory W.; Satterwhite-Warden, Jennifer E.; Kadimisetty, Karteek; Rusling, James F. 2016-07-01 While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices. 3. 3D Biomaterial Microarrays for Regenerative Medicine DEFF Research Database (Denmark) Gaharwar, Akhilesh K.; Arpanaei, Ayyoob; Andresen, Thomas Lars; 2015-01-01 Three dimensional (3D) biomaterial microarrays hold enormous promise for regenerative medicine because of their ability to accelerate the design and fabrication of biomimetic materials. Such tissue-like biomaterials can provide an appropriate microenvironment for stimulating and controlling stem... 4. Lightning fast animation in Element 3D CERN Document Server Audronis, Ty 2014-01-01 An easy-to-follow and all-inclusive guide, in which the underlying principles of 3D animation as well as their importance are explained in detail. The lessons are designed to teach you how to think of 3D animation in such a way that you can troubleshoot any problem, or animate any scene that comes your way.If you are a Digital Artist, Animation Artist, or a Game Programmer and you want to become an expert in Element 3D, this is the book for you. Although there are a lot of basics for beginners in this book, it includes some advanced techniques for both animating in Element 3D, and overcoming i 5. 3D VISUALIZATION FOR VIRTUAL MUSEUM DEVELOPMENT Directory of Open Access Journals (Sweden) M. Skamantzari 2016-06-01 Full Text Available The interest in the development of virtual museums is nowadays rising rapidly. During the last decades there have been numerous efforts concerning the 3D digitization of cultural heritage and the development of virtual museums, digital libraries and serious games. The realistic result has always been the main concern and a real challenge when it comes to 3D modelling of monuments, artifacts and especially sculptures. This paper implements, investigates and evaluates the results of the photogrammetric methods and 3D surveys that were used for the development of a virtual museum. Moreover, the decisions, the actions, the methodology and the main elements that this kind of application should include and take into consideration are described and analysed. It is believed that the outcomes of this application will be useful to researchers who are planning to develop and further improve the attempts made on virtual museums and mass production of 3D models. 6. Pentingnya Pengetahuan Anatomi untuk 3D Artist Directory of Open Access Journals (Sweden) Anton Sugito Kurniawan 2011-03-01 Full Text Available No matter how far the current technological advances, anatomical knowledge will still be needed as a basis for making a good character design. Understanding anatomy will help us in the placement of the articulation of muscles and joints, thus more realistic modeling of 3d characters will be achieved in the form and movement. As a 3d character artist, anatomy should be able to inform in every aspect of our work. Each 3D/CG (Computer Graphics-artist needs to know how to use software applications, but what differentiates a 3d artist with a computer operator is an artistic vision and understanding of the basic shape of the human body. Artistic vision could not easily be taught, but a CG-artist may study it on their own from which so many reference sources may help understand and deepen their knowledge of anatomy. 7. Copper Electrodeposition for 3D Integration CERN Document Server Beica, Rozalia; Ritzdorf, Tom 2008-01-01 Two dimensional (2D) integration has been the traditional approach for IC integration. Due to increasing demands for providing electronic devices with superior performance and functionality in more efficient and compact packages, has driven the semiconductor industry to develop more advanced packaging technologies. Three-dimensional (3D) approaches address both miniaturization and integration required for advanced and portable electronic products. Vertical integration proved to be essential in achieving a greater integration flexibility of disparate technologies, reason for which a general trend of transition from 2D to 3D integration is currently being observed in the industry. 3D chip integration using through silicon via (TSV) copper is considered one of the most advanced technologies among all different types of 3D packaging technologies. Copper electrodeposition is one of technologies that enable the formation of TSV structures. Because of its well-known application for copper damascene, it was believed ... 8. DNA biosensing with 3D printing technology. Science.gov (United States) Loo, Adeline Huiling; Chua, Chun Kiang; Pumera, Martin 2017-01-16 3D printing, an upcoming technology, has vast potential to transform conventional fabrication processes due to the numerous improvements it can offer to the current methods. To date, the employment of 3D printing technology has been examined for applications in the fields of engineering, manufacturing and biological sciences. In this study, we examined the potential of adopting 3D printing technology for a novel application, electrochemical DNA biosensing. Metal 3D printing was utilized to construct helical-shaped stainless steel electrodes which functioned as a transducing platform for the detection of DNA hybridization. The ability of electroactive methylene blue to intercalate into the double helix structure of double-stranded DNA was then exploited to monitor the DNA hybridization process, with its inherent reduction peak serving as an analytical signal. The designed biosensing approach was found to demonstrate superior selectivity against a non-complementary DNA target, with a detection range of 1-1000 nM. 9. Networked 3D Virtual Museum System Institute of Scientific and Technical Information of China (English) 2003-01-01 Virtual heritage has become increasingly important in the conservation, preservation, and interpretation of our cultural and natural history. Moreover, rapid advances in digital technologies in recent years offer virtual heritage new direction. This paper introduces our approach toward a networked 3D virtual museum system, especially, how to model, manage, present virtual heritages and furthermore how to use computer network for the share of virtual heritage in the networked virtual environment. This paper first addresses a 3D acquisition and processing technique for virtual heritage modeling and shows some illustrative examples. Then, this paper describes a management of virtual heritage assets that are composed by various rich media. This paper introduces our schemes to present the virtual heritages, which include 3D virtual heritage browser system, CAVE system, and immersive VR theater. Finally, this paper presents the new direction of networked 3D virtual museum of which main idea is remote guide of the virtual heritage using the mixed reality technique. 10. The 3-d view of planetary nebulae Directory of Open Access Journals (Sweden) Hugo E. Schwarz 2006-01-01 Full Text Available Considerando las nebulosas planetarias (PNe de manera tridimensional (3-D, demonstramos que se pueden reducir las grandes incertidumbres asociadas con los m etodos cl asicos de modelar y observar PNe para obtener sus estructuras 3-D y distancias. Usando espectrofotometr a de ranura larga o empleando un Integral Field Unit para restringir los modelos de fotoionizaci on 3-D de PNe y as eliminar dicha incertidumbre de la densidad y de la fracci on del volumen que emite radiaci on ( lling factor, determinamos las detalladas estructuras 3-D, los par ametros de las estrellas centrales y las distancias con una precisi on de 10-20%. Los m etodos cl asicos t picamente daban estos par ametros con una incertidumbre de un factor 3 o m as. 11. Advanced 3D Object Identification System Project Data.gov (United States) National Aeronautics and Space Administration — Optra will build an Advanced 3D Object Identification System utilizing three or more high resolution imagers spaced around a launch platform. Data from each imager... 12. 3D-FPA Hybridization Improvements Project Data.gov (United States) National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time... 13. Pentingnya Pengetahuan Anatomi Untuk 3D Artist Directory of Open Access Journals (Sweden) Anton Sugito Kurniawan 2011-04-01 Full Text Available No matter how far the current technological advances, anatomical knowledge will still be needed as a basis for making a good character design. Understanding anatomy will help us in the placement of the articulation of muscles and joints, thus more realistic modeling of 3d characters will be achieved in the form and movement. As a 3d character artist, anatomy should be able to inform in every aspect of our work. Each 3D/CG (Computer Graphics-artist needs to know how to use software applications, but what differentiates a 3d artist with a computer operator is an artistic vision and understanding of the basic shape of the human body. Artistic vision could not easily be taught, but a CG-artist may study it on their own from which so many reference sources may help understand and deepen their knowledge of anatomy. 14. Cubical Cohomology Ring of 3D Photographs CERN Document Server Gonzalez-Diaz, Rocio; Medrano, Belen; 10.1002/ima.20271 2011-01-01 Cohomology and cohomology ring of three-dimensional (3D) objects are topological invariants that characterize holes and their relations. Cohomology ring has been traditionally computed on simplicial complexes. Nevertheless, cubical complexes deal directly with the voxels in 3D images, no additional triangulation is necessary, facilitating efficient algorithms for the computation of topological invariants in the image context. In this paper, we present formulas to directly compute the cohomology ring of 3D cubical complexes without making use of any additional triangulation. Starting from a cubical complexQ$that represents a 3D binary-valued digital picture whose foreground has one connected component, we compute first the cohomological information on the boundary of the object,$\\partial Q$by an incremental technique; then, using a face reduction algorithm, we compute it on the whole object; finally, applying the mentioned formulas, the cohomology ring is computed from such information. 15. 3DSEM: A 3D microscopy dataset Directory of Open Access Journals (Sweden) Ahmad P. Tafti 2016-03-01 Full Text Available The Scanning Electron Microscope (SEM as a 2D imaging instrument has been widely used in many scientific disciplines including biological, mechanical, and materials sciences to determine the surface attributes of microscopic objects. However the SEM micrographs still remain 2D images. To effectively measure and visualize the surface properties, we need to truly restore the 3D shape model from 2D SEM images. Having 3D surfaces would provide anatomic shape of micro-samples which allows for quantitative measurements and informative visualization of the specimens being investigated. The 3DSEM is a dataset for 3D microscopy vision which is freely available at [1] for any academic, educational, and research purposes. The dataset includes both 2D images and 3D reconstructed surfaces of several real microscopic samples. 16. Measuring Visual Closeness of 3-D Models KAUST Repository Gollaz Morales, Jose Alejandro 2012-09-01 Measuring visual closeness of 3-D models is an important issue for different problems and there is still no standardized metric or algorithm to do it. The normal of a surface plays a vital role in the shading of a 3-D object. Motivated by this, we developed two applications to measure visualcloseness, introducing normal difference as a parameter in a weighted metric in Metro’s sampling approach to obtain the maximum and mean distance between 3-D models using 3-D and 6-D correspondence search structures. A visual closeness metric should provide accurate information on what the human observers would perceive as visually close objects. We performed a validation study with a group of people to evaluate the correlation of our metrics with subjective perception. The results were positive since the metrics predicted the subjective rankings more accurately than the Hausdorff distance. 17. Intrinsic defects in 3D printed materials OpenAIRE Bolton, Christopher; Dagastine, Raymond 2015-01-01 We discuss the impact of bulk structural defects on the coherence, phase and polarisation of light passing through transparent 3D printed materials fabricated using a variety of commercial print technologies. 18. Designing Biomaterials for 3D Printing. Science.gov (United States) Guvendiren, Murat; Molde, Joseph; Soares, Rosane M D; Kohn, Joachim 2016-10-10 Three-dimensional (3D) printing is becoming an increasingly common technique to fabricate scaffolds and devices for tissue engineering applications. This is due to the potential of 3D printing to provide patient-specific designs, high structural complexity, rapid on-demand fabrication at a low-cost. One of the major bottlenecks that limits the widespread acceptance of 3D printing in biomanufacturing is the lack of diversity in "biomaterial inks". Printability of a biomaterial is determined by the printing technique. Although a wide range of biomaterial inks including polymers, ceramics, hydrogels and composites have been developed, the field is still struggling with processing of these materials into self-supporting devices with tunable mechanics, degradation, and bioactivity. This review aims to highlight the past and recent advances in biomaterial ink development and design considerations moving forward. A brief overview of 3D printing technologies focusing on ink design parameters is also included. 19. Separate Perceptual and Neural Processing of Velocity- and Disparity-Based 3D Motion Signals. Science.gov (United States) Joo, Sung Jun; Czuba, Thaddeus B; Cormack, Lawrence K; Huk, Alexander C 2016-10-19 Although the visual system uses both velocity- and disparity-based binocular information for computing 3D motion, it is unknown whether (and how) these two signals interact. We found that these two binocular signals are processed distinctly at the levels of both cortical activity in human MT and perception. In human MT, adaptation to both velocity-based and disparity-based 3D motions demonstrated direction-selective neuroimaging responses. However, when adaptation to one cue was probed using the other cue, there was no evidence of interaction between them (i.e., there was no "cross-cue" adaptation). Analogous psychophysical measurements yielded correspondingly weak cross-cue motion aftereffects (MAEs) in the face of very strong within-cue adaptation. In a direct test of perceptual independence, adapting to opposite 3D directions generated by different binocular cues resulted in simultaneous, superimposed, opposite-direction MAEs. These findings suggest that velocity- and disparity-based 3D motion signals may both flow through area MT but constitute distinct signals and pathways. Recent human neuroimaging and monkey electrophysiology have revealed 3D motion selectivity in area MT, which is driven by both velocity-based and disparity-based 3D motion signals. However, to elucidate the neural mechanisms by which the brain extracts 3D motion given these binocular signals, it is essential to understand how-or indeed if-these two binocular cues interact. We show that velocity-based and disparity-based signals are mostly separate at the levels of both fMRI responses in area MT and perception. Our findings suggest that the two binocular cues for 3D motion might be processed by separate specialized mechanisms. Copyright © 2016 the authors 0270-6474/16/3610791-12$15.00/0.
20. 3D shape measurement with phase correlation based fringe projection
Science.gov (United States)
Kühmstedt, Peter; Munckelt, Christoph; Heinze, Matthias; Bräuer-Burchardt, Christian; Notni, Gunther
2007-06-01
Here we propose a method for 3D shape measurement by means of phase correlation based fringe projection in a stereo arrangement. The novelty in the approach is characterized by following features. Correlation between phase values of the images of two cameras is used for the co-ordinate calculation. This work stands in contrast to the sole usage of phase values (phasogrammetry) or classical triangulation (phase values and image co-ordinates - camera raster values) for the determination of the co-ordinates. The method's main advantage is the insensitivity of the 3D-coordinates from the absolute phase values. Thus it prevents errors in the determination of the co-ordinates and improves robustness in areas with interreflections artefacts and inhomogeneous regions of intensity. A technical advantage is the fact that the accuracy of the 3D co-ordinates does not depend on the projection resolution. Thus the achievable quality of the 3D co-ordinates can be selectively improved by the use of high quality camera lenses and can participate in improvements in modern camera technologies. The presented new solution of the stereo based fringe projection with phase correlation makes a flexible, errortolerant realization of measuring systems within different applications like quality control, rapid prototyping, design and CAD/CAM possible. In the paper the phase correlation method will be described in detail. Furthermore, different realizations will be shown, i.e. a mobile system for the measurement of large objects and an endoscopic like system for CAD/CAM in dental industry.
1. Fabrication of 3D-culture platform with sandwich architecture for preserving liver-specific functions of hepatocytes using 3D bioprinter.
Science.gov (United States)
Arai, Kenichi; Yoshida, Toshiko; Okabe, Motonori; Goto, Mitsuaki; Mir, Tanveer Ahmad; Soko, Chika; Tsukamoto, Yoshinari; Akaike, Toshihiro; Nikaido, Toshio; Zhou, Kaixuan; Nakamura, Makoto
2017-06-01
The development of new three-dimensional (3D) cell culture system that maintains the physiologically relevant signals of hepatocytes is essential in drug discovery and tissue engineering research. Conventional two-dimensional (2D) culture yields cell growth, proliferation, and differentiation. However, gene expression and signaling profiles can be different from in vivo environment. Here, we report the fabrication of a 3D culture system using an artificial scaffold and our custom-made inkjet 3D bioprinter as a new strategy for studying liver-specific functions of hepatocytes. We built a 3D culture platform for hepatocytes-attachment and formation of cell monolayer by interacting the galactose chain of galactosylated alginate gel (GA-gel) with asialoglycoprotein receptor (ASGPR) of hepatocytes. The 3D geometrical arrangement of cells was controlled by using 3D bioprinter, and cell polarity was controlled with the galactosylated hydrogels. The fabricated GA-gel was able to successfully promote adhesion of hepatocytes. To observe liver-specific functions and to mimic hepatic cord, an additional parallel layer of hepatocytes was generated using two gel sheets. These results indicated that GA-gel biomimetic matrices can be used as a 3D culture system that could be effective for the engineering of liver tissues. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1583-1592, 2017. © 2017 Wiley Periodicals, Inc.
2. Stereo 3D spatial phase diagrams
Energy Technology Data Exchange (ETDEWEB)
Kang, Jinwu, E-mail: [email protected]; Liu, Baicheng, E-mail: [email protected]
2016-07-15
Phase diagrams serve as the fundamental guidance in materials science and engineering. Binary P-T-X (pressure–temperature–composition) and multi-component phase diagrams are of complex spatial geometry, which brings difficulty for understanding. The authors constructed 3D stereo binary P-T-X, typical ternary and some quaternary phase diagrams. A phase diagram construction algorithm based on the calculated phase reaction data in PandaT was developed. And the 3D stereo phase diagram of Al-Cu-Mg ternary system is presented. These phase diagrams can be illustrated by wireframe, surface, solid or their mixture, isotherms and isopleths can be generated. All of these can be displayed by the three typical display ways: electronic shutter, polarization and anaglyph (for example red-cyan glasses). Especially, they can be printed out with 3D stereo effect on paper, and watched by the aid of anaglyph glasses, which makes 3D stereo book of phase diagrams come to reality. Compared with the traditional illustration way, the front of phase diagrams protrude from the screen and the back stretches far behind of the screen under 3D stereo display, the spatial structure can be clearly and immediately perceived. These 3D stereo phase diagrams are useful in teaching and research. - Highlights: • Stereo 3D phase diagram database was constructed, including binary P-T-X, ternary, some quaternary and real ternary systems. • The phase diagrams can be watched by active shutter or polarized or anaglyph glasses. • The print phase diagrams retains 3D stereo effect which can be achieved by the aid of anaglyph glasses.
3. The Idaho Virtualization Laboratory 3D Pipeline
Directory of Open Access Journals (Sweden)
Nicholas A. Holmer
2014-05-01
Full Text Available Three dimensional (3D virtualization and visualization is an important component of industry, art, museum curation and cultural heritage, yet the step by step process of 3D virtualization has been little discussed. Here we review the Idaho Virtualization Laboratory’s (IVL process of virtualizing a cultural heritage item (artifact from start to finish. Each step is thoroughly explained and illustrated including how the object and its metadata are digitally preserved and ultimately distributed to the world.
4. Mayavi: Making 3D Data Visualization Reusable
OpenAIRE
Varoquaux, Gaël; Ramachandran, Prabhu
2008-01-01
International audience; Mayavi is a general-purpose 3D scientific visualization package. We believe 3D data visualization is a difficult task and different users can benefit from an easy-to-use tool for this purpose. In this article, we focus on how Mayavi addresses the needs of different users with a common code-base, rather than describing the data visualization functionalities of Mayavi, or the visualization model exposed to the user.
5. 3D Printing Electrically Small Spherical Antennas
DEFF Research Database (Denmark)
Kim, Oleksiy S.
2013-01-01
3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations.......3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations....
6. 3D Reconstruction of NMR Images
Directory of Open Access Journals (Sweden)
Peter Izak
2007-01-01
Full Text Available This paper introduces experiment of 3D reconstruction NMR images scanned from magnetic resonance device. There are described methods which can be used for 3D reconstruction magnetic resonance images in biomedical application. The main idea is based on marching cubes algorithm. For this task was chosen sophistication method by program Vision Assistant, which is a part of program LabVIEW.
7. 3D Computer Graphics and Nautical Charts
OpenAIRE
Porathe, Thomas
2011-01-01
This paper gives an overview of an ongoing project using real-time 3D visualization to display nautical charts in a way used by 3D computer games. By displaying the map in an egocentric perspective the need to make cognitively demanding mental rotations are suggested to be removed, leading to faster decision-making and less errors. Experimental results support this hypothesis. Practical tests with limited success have been performed this year.
8. Signal and Noise in 3D Environments
Science.gov (United States)
2015-09-30
1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Signal and Noise in 3D Environments Michael B. Porter...complicated 3D environments . I have also been doing a great deal of work in modeling the noise field (the ocean soundscape) due to various sources...we have emphasized the propagation of ‘signals’. We have become increasingly interested in modeling ‘ noise ’ which can illuminate the ocean environment
9. 3D Printing Electrically Small Spherical Antennas
DEFF Research Database (Denmark)
Kim, Oleksiy S.
2013-01-01
3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations.......3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations....
10. 3D GEO: AN ALTERNATIVE APPROACH
OpenAIRE
2016-01-01
The expression GEO is mostly used to denote relation to the earth. However it should not be confined to what is related to the earth's surface, as other objects also need three dimensional representation and documentation, like cultural heritage objects. They include both tangible and intangible ones. In this paper the 3D data acquisition and 3D modelling of cultural heritage assets are briefly described and their significance is also highlighted. Moreover the organization of such information...
11. 3D steerable wavelets in practice.
Science.gov (United States)
Chenouard, Nicolas; Unser, Michael
2012-11-01
We introduce a systematic and practical design for steerable wavelet frames in 3D. Our steerable wavelets are obtained by applying a 3D version of the generalized Riesz transform to a primary isotropic wavelet frame. The novel transform is self-reversible (tight frame) and its elementary constituents (Riesz wavelets) can be efficiently rotated in any 3D direction by forming appropriate linear combinations. Moreover, the basis functions at a given location can be linearly combined to design custom (and adaptive) steerable wavelets. The features of the proposed method are illustrated with the processing and analysis of 3D biomedical data. In particular, we show how those wavelets can be used to characterize directional patterns and to detect edges by means of a 3D monogenic analysis. We also propose a new inverse-problem formalism along with an optimization algorithm for reconstructing 3D images from a sparse set of wavelet-domain edges. The scheme results in high-quality image reconstructions which demonstrate the feature-reduction ability of the steerable wavelets as well as their potential for solving inverse problems.
12. Auto convergence for stereoscopic 3D cameras
Science.gov (United States)
Zhang, Buyue; Kothandaraman, Sreenivas; Batur, Aziz Umit
2012-03-01
Viewing comfort is an important concern for 3-D capable consumer electronics such as 3-D cameras and TVs. Consumer generated content is typically viewed at a close distance which makes the vergence-accommodation conflict particularly pronounced, causing discomfort and eye fatigue. In this paper, we present a Stereo Auto Convergence (SAC) algorithm for consumer 3-D cameras that reduces the vergence-accommodation conflict on the 3-D display by adjusting the depth of the scene automatically. Our algorithm processes stereo video in realtime and shifts each stereo frame horizontally by an appropriate amount to converge on the chosen object in that frame. The algorithm starts by estimating disparities between the left and right image pairs using correlations of the vertical projections of the image data. The estimated disparities are then analyzed by the algorithm to select a point of convergence. The current and target disparities of the chosen convergence point determines how much horizontal shift is needed. A disparity safety check is then performed to determine whether or not the maximum and minimum disparity limits would be exceeded after auto convergence. If the limits would be exceeded, further adjustments are made to satisfy the safety limits. Finally, desired convergence is achieved by shifting the left and the right frames accordingly. Our algorithm runs real-time at 30 fps on a TI OMAP4 processor. It is tested using an OMAP4 embedded prototype stereo 3-D camera. It significantly improves 3-D viewing comfort.
13. ASSESSING 3D PHOTOGRAMMETRY TECHNIQUES IN CRANIOMETRICS
Directory of Open Access Journals (Sweden)
M. C. Moshobane
2016-06-01
Full Text Available Morphometrics (the measurement of morphological features has been revolutionized by the creation of new techniques to study how organismal shape co-varies with several factors such as ecophenotypy. Ecophenotypy refers to the divergence of phenotypes due to developmental changes induced by local environmental conditions, producing distinct ecophenotypes. None of the techniques hitherto utilized could explicitly address organismal shape in a complete biological form, i.e. three-dimensionally. This study investigates the use of the commercial software, Photomodeler Scanner® (PMSc® three-dimensional (3D modelling software to produce accurate and high-resolution 3D models. Henceforth, the modelling of Subantarctic fur seal (Arctocephalus tropicalis and Antarctic fur seal (Arctocephalus gazella skulls which could allow for 3D measurements. Using this method, sixteen accurate 3D skull models were produced and five metrics were determined. The 3D linear measurements were compared to measurements taken manually with a digital caliper. In addition, repetitive measurements were recorded by varying researchers to determine repeatability. To allow for comparison straight line measurements were taken with the software, assuming that close accord with all manually measured features would illustrate the model’s accurate replication of reality. Measurements were not significantly different demonstrating that realistic 3D skull models can be successfully produced to provide a consistent basis for craniometrics, with the additional benefit of allowing non-linear measurements if required.
14. Assessing 3d Photogrammetry Techniques in Craniometrics
Science.gov (United States)
Moshobane, M. C.; de Bruyn, P. J. N.; Bester, M. N.
2016-06-01
Morphometrics (the measurement of morphological features) has been revolutionized by the creation of new techniques to study how organismal shape co-varies with several factors such as ecophenotypy. Ecophenotypy refers to the divergence of phenotypes due to developmental changes induced by local environmental conditions, producing distinct ecophenotypes. None of the techniques hitherto utilized could explicitly address organismal shape in a complete biological form, i.e. three-dimensionally. This study investigates the use of the commercial software, Photomodeler Scanner® (PMSc®) three-dimensional (3D) modelling software to produce accurate and high-resolution 3D models. Henceforth, the modelling of Subantarctic fur seal (Arctocephalus tropicalis) and Antarctic fur seal (Arctocephalus gazella) skulls which could allow for 3D measurements. Using this method, sixteen accurate 3D skull models were produced and five metrics were determined. The 3D linear measurements were compared to measurements taken manually with a digital caliper. In addition, repetitive measurements were recorded by varying researchers to determine repeatability. To allow for comparison straight line measurements were taken with the software, assuming that close accord with all manually measured features would illustrate the model's accurate replication of reality. Measurements were not significantly different demonstrating that realistic 3D skull models can be successfully produced to provide a consistent basis for craniometrics, with the additional benefit of allowing non-linear measurements if required.
15. 3D Viscoelastic traction force microscopy.
Science.gov (United States)
Toyjanova, Jennet; Hannen, Erin; Bar-Kochba, Eyal; Darling, Eric M; Henann, David L; Franck, Christian
2014-10-28
Native cell-material interactions occur on materials differing in their structural composition, chemistry, and physical compliance. While the last two decades have shown the importance of traction forces during cell-material interactions, they have been almost exclusively presented on purely elastic in vitro materials. Yet, most bodily tissue materials exhibit some level of viscoelasticity, which could play an important role in how cells sense and transduce tractions. To expand the realm of cell traction measurements and to encompass all materials from elastic to viscoelastic, this paper presents a general, and comprehensive approach for quantifying 3D cell tractions in viscoelastic materials. This methodology includes the experimental characterization of the time-dependent material properties for any viscoelastic material with the subsequent mathematical implementation of the determined material model into a 3D traction force microscopy (3D TFM) framework. Utilizing this new 3D viscoelastic TFM (3D VTFM) approach, we quantify the influence of viscosity on the overall material traction calculations and quantify the error associated with omitting time-dependent material effects, as is the case for all other TFM formulations. We anticipate that the 3D VTFM technique will open up new avenues of cell-material investigations on even more physiologically relevant time-dependent materials including collagen and fibrin gels.
16. Towards next generation 3D cameras
Science.gov (United States)
Gupta, Mohit
2017-03-01
We are in the midst of a 3D revolution. Robots enabled by 3D cameras are beginning to autonomously drive cars, perform surgeries, and manage factories. However, when deployed in the real-world, these cameras face several challenges that prevent them from measuring 3D shape reliably. These challenges include large lighting variations (bright sunlight to dark night), presence of scattering media (fog, body tissue), and optically complex materials (metal, plastic). Due to these factors, 3D imaging is often the bottleneck in widespread adoption of several key robotics technologies. I will talk about our work on developing 3D cameras based on time-of-flight and active triangulation that addresses these long-standing problems. This includes designing all-weather' cameras that can perform high-speed 3D scanning in harsh outdoor environments, as well as cameras that recover shape of objects with challenging material properties. These cameras are, for the first time, capable of measuring detailed (<100 microns resolution) scans in extremely demanding scenarios with low-cost components. Several of these cameras are making a practical impact in industrial automation, being adopted in robotic inspection and assembly systems.
17. Computer Graphics Teaching Support using X3D: Extensible 3D Graphics for Web Authors
OpenAIRE
Brutzman, Don
2008-01-01
X3D is the ISO-standard scene-graph language for interactive 3D graphics on the Web. A new course is available for teaching the fundamentals of 3D graphics using Extensible 3D (X3D). Resources include a detailed textbook, an authoring tool, hundreds of example scenes, and detailed slidesets covering each chapter. The published book is commercially available, while all other course-module resources are provided online free under open-source licenses. Numerous other commercial and o...
18. The NIH 3D Print Exchange: A Public Resource for Bioscientific and Biomedical 3D Prints
OpenAIRE
Coakley, Meghan F.; Hurt, Darrell E.; Weber, Nick; Mtingwa, Makazi; Fincher, Erin C.; Alekseyev, Vsevelod; Chen, David T.; Yun, Alvin; Gizaw, Metasebia; Swan, Jeremy; Yoo, Terry S.; Huyen, Yentram
2014-01-01
The National Institutes of Health (NIH) has launched the NIH 3D Print Exchange, an online portal for discovering and creating bioscientifically relevant 3D models suitable for 3D printing, to provide both researchers and educators with a trusted source to discover accurate and informative models. There are a number of online resources for 3D prints, but there is a paucity of scientific models, and the expertise required to generate and validate such models remains a barrier. The NIH 3D Print ...
19. NORTH HILL CREEK 3-D SEISMIC EXPLORATION PROJECT
Energy Technology Data Exchange (ETDEWEB)
Marc T. Eckels; David H. Suek; Denise H. Harrison; Paul J. Harrison
2004-05-06
Wind River Resources Corporation (WRRC) received a DOE grant in support of its proposal to acquire, process and interpret fifteen square miles of high-quality 3-D seismic data on non-allotted trust lands of the Uintah and Ouray (Ute) Indian Reservation, northeastern Utah, in 2000. Subsequent to receiving notice that its proposal would be funded, WRRC was able to add ten square miles of adjacent state and federal mineral acreage underlying tribal surface lands by arrangement with the operator of the Flat Rock Field. The twenty-five square mile 3-D seismic survey was conducted during the fall of 2000. The data were processed through the winter of 2000-2001, and initial interpretation took place during the spring of 2001. The initial interpretation identified multiple attractive drilling prospects, two of which were staked and permitted during the summer of 2001. The two initial wells were drilled in September and October of 2001. A deeper test was drilled in June of 2002. Subsequently a ten-well deep drilling evaluation program was conducted from October of 2002 through March 2004. The present report discusses the background of the project; design and execution of the 3-D seismic survey; processing and interpretation of the data; and drilling, completion and production results of a sample of the wells drilled on the basis of the interpreted survey. Fifteen wells have been drilled to test targets identified on the North Hill Creek 3-D Seismic Survey. None of these wildcat exploratory wells has been a dry hole, and several are among the best gas producers in Utah. The quality of the data produced by this first significant exploratory 3-D survey in the Uinta Basin has encouraged other operators to employ this technology. At least two additional 3-D seismic surveys have been completed in the vicinity of the North Hill Creek Survey, and five additional surveys are being planned for the 2004 field season. This project was successful in finding commercial oil, natural gas
20. Power distribution arrangement
DEFF Research Database (Denmark)
2010-01-01
An arrangement and a method for distributing power supplied by a power source to two or more of loads (e.g., electrical vehicular systems) is disclosed, where a representation of the power taken by a particular one of the loads from the source is measured. The measured representation of the amount...
1. Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.
Science.gov (United States)
Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L
2015-06-01
Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.
2. The NIH 3D Print Exchange: A Public Resource for Bioscientific and Biomedical 3D Prints.
Science.gov (United States)
Coakley, Meghan F; Hurt, Darrell E; Weber, Nick; Mtingwa, Makazi; Fincher, Erin C; Alekseyev, Vsevelod; Chen, David T; Yun, Alvin; Gizaw, Metasebia; Swan, Jeremy; Yoo, Terry S; Huyen, Yentram
2014-09-01
The National Institutes of Health (NIH) has launched the NIH 3D Print Exchange, an online portal for discovering and creating bioscientifically relevant 3D models suitable for 3D printing, to provide both researchers and educators with a trusted source to discover accurate and informative models. There are a number of online resources for 3D prints, but there is a paucity of scientific models, and the expertise required to generate and validate such models remains a barrier. The NIH 3D Print Exchange fills this gap by providing novel, web-based tools that empower users with the ability to create ready-to-print 3D files from molecular structure data, microscopy image stacks, and computed tomography scan data. The NIH 3D Print Exchange facilitates open data sharing in a community-driven environment, and also includes various interactive features, as well as information and tutorials on 3D modeling software. As the first government-sponsored website dedicated to 3D printing, the NIH 3D Print Exchange is an important step forward to bringing 3D printing to the mainstream for scientific research and education.
3. 3D-mallien muokkaus 3D-tulostamista varten CAD-ohjelmilla
OpenAIRE
Lehtimäki, Jarmo
2013-01-01
Insinöörityössäni käsitellään 3D-mallien tulostamista ja erityisesti 3D-mallien mallintamista niin, että kappaleiden valmistaminen 3D-tulostimella onnistuisi mahdollisimman hyvin. Työ tehtiin Prohoc Oy:lle, joka sijaitsee Vaasassa. 3D-tulostuspalveluun tuli jatkuvasti 3D-malleja, joiden tulostuksessa oli ongelmia. Työssäni tutkin näiden ongelmien syntyä ja tein ohjeita eri 3D-mallinnusohjelmille, joiden tarkoituksena on auttaa tekemään helpommin tulostettavia 3D-malleja. Työhön kuului myös et...
4. 3D-PRINTING OF BUILD OBJECTS
Directory of Open Access Journals (Sweden)
SAVYTSKYI M. V.
2016-03-01
Full Text Available Raising of problem. Today, in all spheres of our life we can constate the permanent search for new, modern methods and technologies that meet the principles of sustainable development. New approaches need to be, on the one hand more effective in terms of conservation of exhaustible resources of our planet, have minimal impact on the environment and on the other hand to ensure a higher quality of the final product. Construction is not exception. One of the new promising technology is the technology of 3D -printing of individual structures and buildings in general. 3Dprinting - is the process of real object recreating on the model of 3D. Unlike conventional printer which prints information on a sheet of paper, 3D-printer allows you to display three-dimensional information, i.e. creates certain physical objects. Currently, 3D-printer finds its application in many areas of production: machine building elements, a variety of layouts, interior elements, various items. But due to the fact that this technology is fairly new, it requires the creation of detailed and accurate technologies, efficient equipment and materials, and development of common vocabulary and regulatory framework in this field. Research Aim. The analysis of existing methods of creating physical objects using 3D-printing and the improvement of technology and equipment for the printing of buildings and structures. Conclusion. 3D-printers building is a new generation of equipment for the construction of buildings, structures, and structural elements. A variety of building printing technics opens up wide range of opportunities in the construction industry. At this stage, printers design allows to create low-rise buildings of different configurations with different mortars. The scientific novelty of this work is to develop proposals to improve the thermal insulation properties of constructed 3D-printing objects and technological equipment. The list of key terms and notions of construction
5. Nursing care for people with delirium superimposed on dementia.
Science.gov (United States)
Pryor, Claire; Clarke, Amanda
2017-03-31
Nursing and healthcare is changing in response to an ageing population. There is a renewed need for holistic nursing to provide clinically competent, appropriate and timely care for patients who may present with inextricably linked mental and physical health requirements. This article explores the dichotomy in healthcare provision for 'physical' and 'mental' health, and the unique role nurses have when caring for people with delirium superimposed on dementia (DSD). Delirium is prevalent in older people and recognised as 'acute brain failure'. As an acute change in cognition, it presents a unique challenge when occurring in a person with dementia and poses a significant risk of mortality. In this article, dementia is contrasted with delirium and subtypes of delirium presentation are discussed. Nurses can recognise DSD through history gathering, implementation of appropriate care and effective communication with families and the multidisciplinary team. A simple mnemonic called PINCH ME (Pain, INfection, Constipation, deHydration, Medication, Environment) can help identify potential underlying causes of DSD and considerations for care planning. The mnemonic can easily be adapted to different clinical settings and a fictitious scenario is presented to show its application in practice.
6. Thin slice three dimentional (3D reconstruction versus CT 3D reconstruction of human breast cancer
Directory of Open Access Journals (Sweden)
Yi Zhang
2013-01-01
Full Text Available Background & objectives: With improvement in the early diagnosis of breast cancer, breast conserving therapy (BCT is being increasingly used. Precise preoperative evaluation of the incision margin is, therefore, very important. Utilizing three dimentional (3D images in a preoperative evaluation for breast conserving surgery has considerable significance, but the currently 3D CT scan reconstruction commonly used has problems in accurately displaying breast cancer. Thin slice 3D reconstruction is also widely used now to delineate organs and tissues of breast cancers. This study was aimed to compare 3D CT with thin slice 3D reconstruction in breast cancer patients to find a better technique for accurate evaluation of breast cancer. Methods: A total of 16-slice spiral CT scans and 3D reconstructions were performed on 15 breast cancer patients. All patients had been treated with modified radical mastectomy; 2D and 3D images of breast and tumours were obtained. The specimens were fixed and sliced at 2 mm thickness to obtain serial thin slice images, and reconstructed using 3D DOCTOR software to gain 3D images. Results: Compared with 2D CT images, thin slice images showed more clearly the morphological characteristics of tumour, breast tissues and the margins of different tissues in each slice. After 3D reconstruction, the tumour shapes obtained by the two reconstruction methods were basically the same, but the thin slice 3D reconstruction showed the tumour margins more clearly. Interpretation & conclusions: Compared with 3D CT reconstruction, thin slice 3D reconstruction of breast tumour gave clearer images, which could provide guidance for the observation and application of CT 3D reconstructed images and contribute to the accurate evaluation of tumours using CT imaging technology.
7. PLOT3D Export Tool for Tecplot
Science.gov (United States)
Alter, Stephen
2010-01-01
The PLOT3D export tool for Tecplot solves the problem of modified data being impossible to output for use by another computational science solver. The PLOT3D Exporter add-on enables the use of the most commonly available visualization tools to engineers for output of a standard format. The exportation of PLOT3D data from Tecplot has far reaching effects because it allows for grid and solution manipulation within a graphical user interface (GUI) that is easily customized with macro language-based and user-developed GUIs. The add-on also enables the use of Tecplot as an interpolation tool for solution conversion between different grids of different types. This one add-on enhances the functionality of Tecplot so significantly, it offers the ability to incorporate Tecplot into a general suite of tools for computational science applications as a 3D graphics engine for visualization of all data. Within the PLOT3D Export Add-on are several functions that enhance the operations and effectiveness of the add-on. Unlike Tecplot output functions, the PLOT3D Export Add-on enables the use of the zone selection dialog in Tecplot to choose which zones are to be written by offering three distinct options - output of active, inactive, or all zones (grid blocks). As the user modifies the zones to output with the zone selection dialog, the zones to be written are similarly updated. This enables the use of Tecplot to create multiple configurations of a geometry being analyzed. For example, if an aircraft is loaded with multiple deflections of flaps, by activating and deactivating different zones for a specific flap setting, new specific configurations of that aircraft can be easily generated by only writing out specific zones. Thus, if ten flap settings are loaded into Tecplot, the PLOT3D Export software can output ten different configurations, one for each flap setting.
8. Visual Fixation for 3D Video Stabilization
Directory of Open Access Journals (Sweden)
Hans-Peter Seidel
2011-03-01
Full Text Available Visual fixation is employed by humans and some animals to keep a specific 3D location at the center of the visual gaze. Inspired by this phenomenon in nature, this paper explores the idea to transfer this mechanism to the context of video stabilization for a hand-held video camera. A novel approach is presented that stabilizes a video by fixating on automatically extracted 3D target points. This approach is different from existing automatic solutions that stabilize the video by smoothing. To determine the 3D target points, the recorded scene is analyzed with a state-of-the-art structure-from-motion algorithm, which estimates camera motion and reconstructs a 3D point cloud of the static scene objects. Special algorithms are presented that search either virtual or real 3D target points, which back-project close to the center of the image for as long a period of time as possible. The stabilization algorithm then transforms the original images of the sequence so that these 3D target points are kept exactly in the center of the image, which, in case of real 3D target points, produces a perfectly stable result at the image center. Furthermore, different methods of additional user interaction are investigated. It is shown that the stabilization process can easily be controlled and that it can be combined with state-of-the-art tracking techniques in order to obtain a powerful image stabilization tool. The approach is evaluated on a variety of videos taken with a hand-held camera in natural scenes.
9. A microfluidic device for 2D to 3D and 3D to 3D cell navigation
Science.gov (United States)
Shamloo, Amir; Amirifar, Leyla
2016-01-01
Microfluidic devices have received wide attention and shown great potential in the field of tissue engineering and regenerative medicine. Investigating cell response to various stimulations is much more accurate and comprehensive with the aid of microfluidic devices. In this study, we introduced a microfluidic device by which the matrix density as a mechanical property and the concentration profile of a biochemical factor as a chemical property could be altered. Our microfluidic device has a cell tank and a cell culture chamber to mimic both 2D to 3D and 3D to 3D migration of three types of cells. Fluid shear stress is negligible on the cells and a stable concentration gradient can be obtained by diffusion. The device was designed by a numerical simulation so that the uniformity of the concentration gradients throughout the cell culture chamber was obtained. Adult neural cells were cultured within this device and they showed different branching and axonal navigation phenotypes within varying nerve growth factor (NGF) concentration profiles. Neural stem cells were also cultured within varying collagen matrix densities while exposed to NGF concentrations and they experienced 3D to 3D collective migration. By generating vascular endothelial growth factor concentration gradients, adult human dermal microvascular endothelial cells also migrated in a 2D to 3D manner and formed a stable lumen within a specific collagen matrix density. It was observed that a minimum absolute concentration and concentration gradient were required to stimulate migration of all types of the cells. This device has the advantage of changing multiple parameters simultaneously and is expected to have wide applicability in cell studies.
10. Full-color holographic 3D printer
Science.gov (United States)
Takano, Masami; Shigeta, Hiroaki; Nishihara, Takashi; Yamaguchi, Masahiro; Takahashi, Susumu; Ohyama, Nagaaki; Kobayashi, Akihiko; Iwata, Fujio
2003-05-01
A holographic 3D printer is a system that produces a direct hologram with full-parallax information using the 3-dimensional data of a subject from a computer. In this paper, we present a proposal for the reproduction of full-color images with the holographic 3D printer. In order to realize the 3-dimensional color image, we selected the 3 laser wavelength colors of red (λ=633nm), green (λ=533nm), and blue (λ=442nm), and we built a one-step optical system using a projection system and a liquid crystal display. The 3-dimensional color image is obtained by synthesizing in a 2D array the multiple exposure with these 3 wavelengths made on each 250mm elementary hologram, and moving recording medium on a x-y stage. For the natural color reproduction in the holographic 3D printer, we take the approach of the digital processing technique based on the color management technology. The matching between the input and output colors is performed by investigating first, the relation between the gray level transmittance of the LCD and the diffraction efficiency of the hologram and second, by measuring the color displayed by the hologram to establish a correlation. In our first experimental results a non-linear functional relation for single and multiple exposure of the three components were found. These results are the first step in the realization of a natural color 3D image produced by the holographic color 3D printer.
11. 3D bioprinting for engineering complex tissues.
Science.gov (United States)
Mandrycky, Christian; Wang, Zongjie; Kim, Keekyoung; Kim, Deok-Ho
2016-01-01
Bioprinting is a 3D fabrication technology used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. While still in its early stages, bioprinting strategies have demonstrated their potential use in regenerative medicine to generate a variety of transplantable tissues, including skin, cartilage, and bone. However, current bioprinting approaches still have technical challenges in terms of high-resolution cell deposition, controlled cell distributions, vascularization, and innervation within complex 3D tissues. While no one-size-fits-all approach to bioprinting has emerged, it remains an on-demand, versatile fabrication technique that may address the growing organ shortage as well as provide a high-throughput method for cell patterning at the micrometer scale for broad biomedical engineering applications. In this review, we introduce the basic principles, materials, integration strategies and applications of bioprinting. We also discuss the recent developments, current challenges and future prospects of 3D bioprinting for engineering complex tissues. Combined with recent advances in human pluripotent stem cell technologies, 3D-bioprinted tissue models could serve as an enabling platform for high-throughput predictive drug screening and more effective regenerative therapies.
12. Magnetic Properties of 3D Printed Toroids
Science.gov (United States)
Bollig, Lindsey; Otto, Austin; Hilpisch, Peter; Mowry, Greg; Nelson-Cheeseman, Brittany; Renewable Energy; Alternatives Lab (REAL) Team
Transformers are ubiquitous in electronics today. Although toroidal geometries perform most efficiently, transformers are traditionally made with rectangular cross-sections due to the lower manufacturing costs. Additive manufacturing techniques (3D printing) can easily achieve toroidal geometries by building up a part through a series of 2D layers. To get strong magnetic properties in a 3D printed transformer, a composite filament is used containing Fe dispersed in a polymer matrix. How the resulting 3D printed toroid responds to a magnetic field depends on two structural factors of the printed 2D layers: fill factor (planar density) and fill pattern. In this work, we investigate how the fill factor and fill pattern affect the magnetic properties of 3D printed toroids. The magnetic properties of the printed toroids are measured by a custom circuit that produces a hysteresis loop for each toroid. Toroids with various fill factors and fill patterns are compared to determine how these two factors can affect the magnetic field the toroid can produce. These 3D printed toroids can be used for numerous applications in order to increase the efficiency of transformers by making it possible for manufacturers to make a toroidal geometry.
13. Heat Equation to 3D Image Segmentation
Directory of Open Access Journals (Sweden)
Nikolay Sirakov
2006-04-01
Full Text Available This paper presents a new approach, capable of 3D image segmentation and objects' surface reconstruction. The main advantages of the method are: large capture range; quick segmentation of a 3D scene/image to regions; multiple 3D objects reconstruction. The method uses centripetal force and penalty function to segment the entire 3D scene/image to regions containing a single 3D object. Each region is inscribed in a convex, smooth closed surface, which defines a centripetal force. Then the surface is evolved by the geometric heat differential equation toward the force's direction. The penalty function is defined to stop evolvement of those surface patches, whose normal vectors encountered object's surface. On the base of the theoretical model Forward Difference Algorithm was developed and coded by Mathematica. Stability convergence condition, truncation error and calculation complexity of the algorithm are determined. The obtained results, advantages and disadvantages of the method are discussed at the end of this paper.
14. BEAMS3D Neutral Beam Injection Model
Science.gov (United States)
McMillan, Matthew; Lazerson, Samuel A.
2014-09-01
With the advent of applied 3D fields in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous slowing down, and pitch angle scattering are modeled with the ADAS atomic physics database. Elementary benchmark calculations are presented to verify the collisionless particle orbits, NBI model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields. Notice: this manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.
15. Recent Progress on 3D Silicon Detectors
CERN Document Server
Lange, Jörn
2015-01-01
3D silicon detectors, in which the electrodes penetrate the sensor bulk perpendicular to the surface, have recently undergone a rapid development from R\\&D over industrialisation to their first installation in a real high-energy-physics experiment. Since June 2015, the ATLAS Insertable B-Layer is taking first collision data with 3D pixel detectors. At the same time, preparations are advancing to install 3D pixel detectors in forward trackers such as the ATLAS Forward Proton detector or the CMS-TOTEM Proton Precision Spectrometer. For those experiments, the main requirements are a slim edge and the ability to cope with non-uniform irradiation. Both have been shown to be fulfilled by 3D pixel detectors. For the High-Luminosity LHC pixel upgrades of the major experiments, 3D detectors are promising candidates for the innermost pixel layers to cope with harsh radiation environments up to fluences of $2\\times10^{16}$\\,n$_{eq}$/cm$^2$ thanks to their excellent radiation hardness at low operational voltages and ...
16. Miniaturized 3D microscope imaging system
Science.gov (United States)
Lan, Yung-Sung; Chang, Chir-Weei; Sung, Hsin-Yueh; Wang, Yen-Chang; Chang, Cheng-Yi
2015-05-01
We designed and assembled a portable 3-D miniature microscopic image system with the size of 35x35x105 mm3 . By integrating a microlens array (MLA) into the optical train of a handheld microscope, the biological specimen's image will be captured for ease of use in a single shot. With the light field raw data and program, the focal plane can be changed digitally and the 3-D image can be reconstructed after the image was taken. To localize an object in a 3-D volume, an automated data analysis algorithm to precisely distinguish profundity position is needed. The ability to create focal stacks from a single image allows moving or specimens to be recorded. Applying light field microscope algorithm to these focal stacks, a set of cross sections will be produced, which can be visualized using 3-D rendering. Furthermore, we have developed a series of design rules in order to enhance the pixel using efficiency and reduce the crosstalk between each microlens for obtain good image quality. In this paper, we demonstrate a handheld light field microscope (HLFM) to distinguish two different color fluorescence particles separated by a cover glass in a 600um range, show its focal stacks, and 3-D position.
17. CLIP: similarity searching of 3D databases using clique detection.
Science.gov (United States)
Rhodes, Nicholas; Willett, Peter; Calvet, Alain; Dunbar, James B; Humblet, Christine
2003-01-01
This paper describes a program for 3D similarity searching, called CLIP (for Candidate Ligand Identification Program), that uses the Bron-Kerbosch clique detection algorithm to find those structures in a file that have large structures in common with a target structure. Structures are characterized by the geometric arrangement of pharmacophore points and the similarity between two structures calculated using modifications of the Simpson and Tanimoto association coefficients. This modification takes into account the fact that a distance tolerance is required to ensure that pairs of interatomic distances can be regarded as equivalent during the clique-construction stage of the matching algorithm. Experiments with HIV assay data demonstrate the effectiveness and the efficiency of this approach to virtual screening.
18. Fluorescence in situ hybridization applications for super-resolution 3D structured illumination microscopy.
Science.gov (United States)
Markaki, Yolanda; Smeets, Daniel; Cremer, Marion; Schermelleh, Lothar
2013-01-01
Fluorescence in situ hybridization on three-dimensionally preserved cells (3D-FISH) is an efficient tool to analyze the subcellular localization and spatial arrangement of targeted DNA sequences and RNA transcripts at the single cell level. 3D reconstructions from serial optical sections obtained by confocal laser scanning microscopy (CLSM) have long been considered the gold standard for 3D-FISH analyses. Recent super-resolution techniques circumvent the diffraction-limit of optical resolution and have defined a new state-of-the-art in bioimaging. Three-dimensional structured illumination microscopy (3D-SIM) represents one of these technologies. Notably, 3D-SIM renders an eightfold improved volumetric resolution over conventional imaging, and allows the simultaneous visualization of differently labeled target structures. These features make this approach highly attractive for the analysis of spatial relations and substructures of nuclear targets that escape detection by conventional light microscopy. Here, we focus on the application of 3D-SIM for the visualization of subnuclear 3D-FISH preparations. In comparison with conventional fluorescence microscopy, the quality of 3D-SIM data is dependent to a much greater extent on the optimal sample preparation, labeling and acquisition conditions. We describe typical problems encountered with super-resolution imaging of in situ hybridizations in mammalian tissue culture cells and provide optimized DNA-/(RNA)-FISH protocols including combinations with immunofluorescence staining (Immuno-FISH) and DNA replication labeling using click chemistry.
19. Intermediate links of line arrangements
CERN Document Server
Bodin, Arnaud
2012-01-01
We investigate several topological properties of line arrangements. The first result is that two generic complex line arrangements are equivalent. In fact for a line arrangement A we associate its defining polynomial f= prod_i (a_ix+b_iy+c_i), so that A = (f=0). We even prove that the defining polynomials of two generic line arrangements are topologically equivalent. In higher dimension the related result is that within a family of equivalent hyperplane arrangements the defining polynomials are topologically equivalent. A second type of objects associated to a line arrangement are links A cap S^3_r(0) obtained by intersecting the arrangement with some spheres. Several topics are discussed: (a) some link configurations can be realized by complex line arrangements but not by real line arrangements; (b) if we intersect the arrangements with a vertical band instead of a sphere, what link configurations can be obtained? (c) relations between link configurations obtained by bands and spheres.
20. Imaging arrangement and microscope
Science.gov (United States)
Pertsinidis, Alexandros; Chu, Steven
2015-12-15
An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.
1. Steerable catoptric arrangements
Energy Technology Data Exchange (ETDEWEB)
Rambauske, W.R.
1976-04-13
Catoptric arrangements for steering a laser beam by moving one, or more, mirrors relative to two substantially orthogonal axis of rotation are shown. In the various embodiments illustrated, one of such axes of rotation, around which all of the mirrors in each embodiment are rotatable, is coincident with the longitudinal axis of the laser beam to be steered so as to direct such longitudinal axis toward different points on a first focal circle. Means are provided to rotate all of the mirrors in each embodiment, except the mirror irradiated by the laser beam to be steered, around the second axis of rotation to direct the longitudinal axis of such beam toward different points on a second focal circle substantially orthogonal to the first focal circle. Also shown are exemplary modifications to position the mirrors within each arrangement to aim the steered beam to points adjacent to the first and second focal circles.
2. Hyperplane arrangements an introduction
CERN Document Server
Dimca, Alexandru
2017-01-01
This textbook provides an accessible introduction to the rich and beautiful area of hyperplane arrangement theory, where discrete mathematics, in the form of combinatorics and arithmetic, meets continuous mathematics, in the form of the topology and Hodge theory of complex algebraic varieties. The topics discussed in this book range from elementary combinatorics and discrete geometry to more advanced material on mixed Hodge structures, logarithmic connections and Milnor fibrations. The author covers a lot of ground in a relatively short amount of space, with a focus on defining concepts carefully and giving proofs of theorems in detail where needed. Including a number of surprising results and tantalizing open problems, this timely book also serves to acquaint the reader with the rapidly expanding literature on the subject. Hyperplane Arrangements will be particularly useful to graduate students and researchers who are interested in algebraic geometry or algebraic topology. The book contains numerous exercise...
3. A Hybrid 3D Indoor Space Model
Science.gov (United States)
Jamali, Ali; Rahman, Alias Abdul; Boguslawski, Pawel
2016-10-01
GIS integrates spatial information and spatial analysis. An important example of such integration is for emergency response which requires route planning inside and outside of a building. Route planning requires detailed information related to indoor and outdoor environment. Indoor navigation network models including Geometric Network Model (GNM), Navigable Space Model, sub-division model and regular-grid model lack indoor data sources and abstraction methods. In this paper, a hybrid indoor space model is proposed. In the proposed method, 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. This research proposes a method of indoor space modeling for the buildings which do not have proper 2D/3D geometrical models or they lack semantic or topological information. The proposed hybrid model consists of topological, geometrical and semantical space.
4. A Hybrid 3D Indoor Space Model
Directory of Open Access Journals (Sweden)
A. Jamali
2016-10-01
Full Text Available GIS integrates spatial information and spatial analysis. An important example of such integration is for emergency response which requires route planning inside and outside of a building. Route planning requires detailed information related to indoor and outdoor environment. Indoor navigation network models including Geometric Network Model (GNM, Navigable Space Model, sub-division model and regular-grid model lack indoor data sources and abstraction methods. In this paper, a hybrid indoor space model is proposed. In the proposed method, 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. This research proposes a method of indoor space modeling for the buildings which do not have proper 2D/3D geometrical models or they lack semantic or topological information. The proposed hybrid model consists of topological, geometrical and semantical space.
5. Solving a 3D structural puzzle
DEFF Research Database (Denmark)
Hoeck, Casper
to spatial structural information using NMR spectroscopy. Experimental distances from nuclear Overhauser effect (NOE) correlations, and dihedral angles from 3JHH-coupling constants, were used to obtain 3D structural information for several natural and synthetic compounds. The stereochemistry of novel natural...... samples, which allows for RDCs to be extracted. The number of internuclear vectors for the correlation of RDCs to 3D structures is often limited for small molecules. Homonuclear RDCs were extracted by use of the homonuclear S3 HMBC that correlated well to alignment tensors from 1DCH-coupling constants......-calculation of RDCs from 3D structures was developed and tested, which copes better with multiple conformers than the commonly used SVD methodology. The approach thus resulted in good conformer populations for several small molecules, including multiple cinchona alkaloids....
6. 3D nanopillar optical antenna photodetectors.
Science.gov (United States)
Senanayake, Pradeep; Hung, Chung-Hong; Shapiro, Joshua; Scofield, Adam; Lin, Andrew; Williams, Benjamin S; Huffaker, Diana L
2012-11-05
We demonstrate 3D surface plasmon photoresponse in nanopillar arrays resulting in enhanced responsivity due to both Localized Surface Plasmon Resonances (LSPRs) and Surface Plasmon Polariton Bloch Waves (SPP-BWs). The LSPRs are excited due to a partial gold shell coating the nanopillar which acts as a 3D Nanopillar Optical Antenna (NOA) in focusing light into the nanopillar. Angular photoresponse measurements show that SPP-BWs can be spectrally coincident with LSPRs to result in a x2 enhancement in responsivity at 1180 nm. Full-wave Finite Difference Time Domain (FDTD) simulations substantiate both the spatial and spectral coupling of the SPP-BW / LSPR for enhanced absorption and the nature of the LSPR. Geometrical control of the 3D NOA and the self-aligned metal hole lattice allows the hybridization of both localized and propagating surface plasmon modes for enhanced absorption. Hybridized plasmonic modes opens up new avenues in optical antenna design in nanoscale photodetectors.
7. Multiplane 3D superresolution optical fluctuation imaging
CERN Document Server
Geissbuehler, Stefan; Godinat, Aurélien; Bocchio, Noelia L; Dubikovskaya, Elena A; Lasser, Theo; Leutenegger, Marcel
2013-01-01
By switching fluorophores on and off in either a deterministic or a stochastic manner, superresolution microscopy has enabled the imaging of biological structures at resolutions well beyond the diffraction limit. Superresolution optical fluctuation imaging (SOFI) provides an elegant way of overcoming the diffraction limit in all three spatial dimensions by computing higher-order cumulants of image sequences of blinking fluorophores acquired with a conventional widefield microscope. So far, three-dimensional (3D) SOFI has only been demonstrated by sequential imaging of multiple depth positions. Here we introduce a versatile imaging scheme which allows for the simultaneous acquisition of multiple focal planes. Using 3D cross-cumulants, we show that the depth sampling can be increased. Consequently, the simultaneous acquisition of multiple focal planes reduces the acquisition time and hence the photo-bleaching of fluorescent markers. We demonstrate multiplane 3D SOFI by imaging the mitochondria network in fixed ...
8. 3D-printed microfluidic devices.
Science.gov (United States)
Amin, Reza; Knowlton, Stephanie; Hart, Alexander; Yenilmez, Bekir; Ghaderinezhad, Fariba; Katebifar, Sara; Messina, Michael; Khademhosseini, Ali; Tasoglu, Savas
2016-06-20
Microfluidics is a flourishing field, enabling a wide range of biochemical and clinical applications such as cancer screening, micro-physiological system engineering, high-throughput drug testing, and point-of-care diagnostics. However, fabrication of microfluidic devices is often complicated, time consuming, and requires expensive equipment and sophisticated cleanroom facilities. Three-dimensional (3D) printing presents a promising alternative to traditional techniques such as lithography and PDMS-glass bonding, not only by enabling rapid design iterations in the development stage, but also by reducing the costs associated with institutional infrastructure, equipment installation, maintenance, and physical space. With the recent advancements in 3D printing technologies, highly complex microfluidic devices can be fabricated via single-step, rapid, and cost-effective protocols, making microfluidics more accessible to users. In this review, we discuss a broad range of approaches for the application of 3D printing technology to fabrication of micro-scale lab-on-a-chip devices.
9. Atomic resolution 3D electron diffraction microscopy
Energy Technology Data Exchange (ETDEWEB)
Miao, Jianwei; Ohsuna, Tetsu; Terasaki, Osamu; O' Keefe, Michael A.
2002-03-01
Electron lens aberration is the major barrier limiting the resolution of electron microscopy. Here we describe a novel form of electron microscopy to overcome electron lens aberration. By combining coherent electron diffraction with the oversampling phasing method, we show that the 3D structure of a 2 x 2 x 2 unit cell nano-crystal (framework of LTA [Al12Si12O48]8) can be ab initio determined at the resolution of 1 Angstrom from a series of simulated noisy diffraction pattern projections with rotation angles ranging from -70 degrees to +70 degrees in 5 degrees increments along a single rotation axis. This form of microscopy (which we call 3D electron diffraction microscopy) does not require any reference waves, and can image the 3D structure of nanocrystals, as well as non-crystalline biological and materials science samples, with the resolution limited only by the quality of sample diffraction.
10. Spectroradiometric characterization of autostereoscopic 3D displays
Science.gov (United States)
Rubiño, Manuel; Salas, Carlos; Pozo, Antonio M.; Castro, J. J.; Pérez-Ocón, Francisco
2013-11-01
Spectroradiometric measurements have been made for the experimental characterization of the RGB channels of autostereoscopic 3D displays, giving results for different measurement angles with respect to the normal direction of the plane of the display. In the study, 2 different models of autostereoscopic 3D displays of different sizes and resolutions were used, making measurements with a spectroradiometer (model PR-670 SpectraScan of PhotoResearch). From the measurements made, goniometric results were recorded for luminance contrast, and the fundamental hypotheses have been evaluated for the characterization of the displays: independence of the RGB channels and their constancy. The results show that the display with the lower angle variability in the contrast-ratio value and constancy of the chromaticity coordinates nevertheless presented the greatest additivity deviations with the measurement angle. For both displays, when the parameters evaluated were taken into account, lower angle variability consistently resulted in the 2D mode than in the 3D mode.
11. Teknologi 3D dalam Proses Pembuatan Komik
Directory of Open Access Journals (Sweden)
2011-04-01
Full Text Available Comic has been people’s favorite since 1930. As the growth of years and technology, the demands in designing comic were also increasing. To fulfill the demands, comic authors spent their times to draw so that they have no time to discover other element besides technical. Therefore, it is important if the comic author helped by 3D technology to accelerate technical process so that the comic authors will get extra time to develop other elements like concept and story. Data is gathered from interviews with both semi-professional and professional comic authors who are having problems being solved. Solving problems are conducted by using 3D software to draw picture of distorted space. And then two semi-professional comic authors will try to draw distorted space in tracing the picture from 3D software to see how many times needed to draw hard part traditionally.
12. Resist loss in 3D compact modeling
Science.gov (United States)
Zheng, Xin; Huang, Jensheng; Chin, Fook; Kazarian, Aram; Kuo, Chun-Chieh
2012-03-01
An enhancement to compact modeling capability to include photoresist (PR) loss at different heights is developed and discussed. A hypsometric map representing 3-D resist profile was built by applying a first principle approximation to estimate the "energy loss" from the resist top to any other plane of interest as a proportional corresponding change in model threshold, which is analogous to a change in exposure dose. The result is compared and validated with 3D rigorous modeling as well as SEM images. Without increase in computation time, this compact model can construct 3D resist profiles capturing resist profile degradation at any vertical plane. Sidewall angle and standing wave information can also be granted from the vertical profile reconstruction. Since this method does not change any form of compact modeling, it can be integrated to validation and correction without any additional work.
13. DNA origami design of 3D nanostructures
DEFF Research Database (Denmark)
Andersen, Ebbe Sloth; Nielsen, Morten Muhlig
2009-01-01
, several dedicated 3D editors for computer-aided design of DNA structures have been developed [4-7]. However, many of these tools are not efficient for designing DNA origami structures that requires the design of more than 200 unique DNA strands to be folded along a scaffold strand into a defined 3D shape......Structural DNA nanotechnology has been heavily dependent on the development of dedicated software tools for the design of unique helical junctions, to define unique sticky-ends for tile assembly, and for predicting the products of the self-assembly reaction of multiple DNA strands [1-3]. Recently...... [8]. We have recently developed a semi-automated DNA origami software package [9] that uses a 2D sequence editor in conjunction with several automated tools to facilitate the design process. Here we extend the use of the program for designing DNA origami structures in 3D and show the application...
14. 3D integral imaging with optical processing
Science.gov (United States)
Martínez-Corral, Manuel; Martínez-Cuenca, Raúl; Saavedra, Genaro; Javidi, Bahram
2008-04-01
Integral imaging (InI) systems are imaging devices that provide auto-stereoscopic images of 3D intensity objects. Since the birth of this new technology, InI systems have faced satisfactorily many of their initial drawbacks. Basically, two kind of procedures have been used: digital and optical procedures. The "3D Imaging and Display Group" at the University of Valencia, with the essential collaboration of Prof. Javidi, has centered its efforts in the 3D InI with optical processing. Among other achievements, our Group has proposed the annular amplitude modulation for enlargement of the depth of field, dynamic focusing for reduction of the facet-braiding effect, or the TRES and MATRES devices to enlarge the viewing angle.
15. Pyrolytic 3D Carbon Microelectrodes for Electrochemistry
DEFF Research Database (Denmark)
Hemanth, Suhith; Caviglia, Claudia; Amato, Letizia
2016-01-01
electrochemical activity, chemical stability, and ease in surface functionalization [1]. The most common carbon microfabrication techniques (i.e. screen printing) produce two-dimensional (2D) electrodes, which limit the detection sensitivity. Hence several 3D microfabrication techniques have been explored......This work presents the fabrication and characterization of multi-layered three-dimensional (3D) pyrolysed carbon microelectrodes for electrochemical applications. For this purpose, an optimized UV photolithography and pyrolysis process with the negative tone photoresist SU-8 has been developed...... carbon [2]. This process enables fabrication of 2D and 3D electrodes with possibility for tailoring ad-hoc designs and unique sensitivities for specific applications. Due to this, pyrolysed carbon is becoming increasingly attractive for numerous applications, such as novel sensors and scaffolds for cell...
16. EU Design Law and 3D Printing
DEFF Research Database (Denmark)
Nordberg, Ana; Schovsbo, Jens Hemmingsen
2017-01-01
The article considers the implications for EU design law of 3D-printing. It first describes the 3D-printing technology and the e-ecosystem which is evolving around the technology and involves a number of new stakeholders who in different ways are engaged in the making and sharing of CAD-files and....../or printing. It is submitted that it is only a matter of time before 3D-printing equipment becomes ubiquitous. It is pointed out how the new technology and e-ecosystem at the same time represent threats and opportunities to design holders and to the societal interests in design and design law. EU design law...
17. 3D Printed Multimaterial Microfluidic Valve
Science.gov (United States)
Patrick, William G.; Sharma, Sunanda; Kong, David S.; Oxman, Neri
2016-01-01
We present a novel 3D printed multimaterial microfluidic proportional valve. The microfluidic valve is a fundamental primitive that enables the development of programmable, automated devices for controlling fluids in a precise manner. We discuss valve characterization results, as well as exploratory design variations in channel width, membrane thickness, and membrane stiffness. Compared to previous single material 3D printed valves that are stiff, these printed valves constrain fluidic deformation spatially, through combinations of stiff and flexible materials, to enable intricate geometries in an actuated, functionally graded device. Research presented marks a shift towards 3D printing multi-property programmable fluidic devices in a single step, in which integrated multimaterial valves can be used to control complex fluidic reactions for a variety of applications, including DNA assembly and analysis, continuous sampling and sensing, and soft robotics. PMID:27525809
18. Structured light field 3D imaging.
Science.gov (United States)
Cai, Zewei; Liu, Xiaoli; Peng, Xiang; Yin, Yongkai; Li, Ameng; Wu, Jiachen; Gao, Bruce Z
2016-09-05
In this paper, we propose a method by means of light field imaging under structured illumination to deal with high dynamic range 3D imaging. Fringe patterns are projected onto a scene and modulated by the scene depth then a structured light field is detected using light field recording devices. The structured light field contains information about ray direction and phase-encoded depth, via which the scene depth can be estimated from different directions. The multidirectional depth estimation can achieve high dynamic 3D imaging effectively. We analyzed and derived the phase-depth mapping in the structured light field and then proposed a flexible ray-based calibration approach to determine the independent mapping coefficients for each ray. Experimental results demonstrated the validity of the proposed method to perform high-quality 3D imaging for highly and lowly reflective surfaces.
19. Novel proposals in widefield 3D microscopy
Science.gov (United States)
Sanchez-Ortiga, E.; Doblas, A.; Saavedra, G.; Martinez-Corral, M.
2010-04-01
Patterned illumination is a successful set of techniques in high resolution 3D microscopy. In particular, structured illumination microscopy is based on the projection of 1D periodic patterns onto the 3D sample under study. In this research we propose the implementation of a very simple method for the flexible production of 1D structured illumination. Specifically, we propose the insertion of a Fresnel biprism after a monochromatic point source. The biprism produces a pair of twin, fully coherent, virtual point sources. After imaging the virtual sources onto the objective aperture stop, the expected 1D periodic pattern is produced into the 3D sample. The main advantage of using the Fresnel biprism is that by simply varying the distance between the biprism and the point source one can tune the period of the fringes while keeping their contrast.
20. 3D face analysis for demographic biometrics
Energy Technology Data Exchange (ETDEWEB)
Tokola, Ryan A [ORNL; Mikkilineni, Aravind K [ORNL; Boehnen, Chris Bensing [ORNL
2015-01-01
Despite being increasingly easy to acquire, 3D data is rarely used for face-based biometrics applications beyond identification. Recent work in image-based demographic biometrics has enjoyed much success, but these approaches suffer from the well-known limitations of 2D representations, particularly variations in illumination, texture, and pose, as well as a fundamental inability to describe 3D shape. This paper shows that simple 3D shape features in a face-based coordinate system are capable of representing many biometric attributes without problem-specific models or specialized domain knowledge. The same feature vector achieves impressive results for problems as diverse as age estimation, gender classification, and race classification.
1. Physiological responses and perceived exertion during cycling with superimposed electromyostimulation.
Science.gov (United States)
Wahl, Patrick; Schaerk, Jonas; Achtzehn, Silvia; Kleinöder, Heinz; Bloch, Wilhelm; Mester, Joachim
2012-09-01
The goal of the study was to evaluate and to quantify the effects of local electromyostimulation (EMS) during cycling on the cardiorespiratory system, muscle metabolism, and perceived exertion compared with cycling with no EMS. Ten healthy men (age: 24.6 ± 3.2 years, V[Combining Dot Above]O2max: 54.1 ± 6.0 ml·min·kg) performed 3 incremental cycle ergometer step tests, 1 without and 2 with EMS (30 and 85 Hz) until volitional exhaustion. Lactate values and respiratory exchange ratio were significantly higher at intensities ≥75% peak power output (PPO) when EMS was applied. Bicarbonate concentration, base excess (BE), and Pco2 were significantly lower when EMS was applied compared with the control at intensities ≥75% PPO. Saliva cortisol levels increased because of the exercise but were unaffected by EMS. Furthermore, EMS showed greater effects on CK levels 24 hours postexercise than normal cycling did. Rating of perceived exertion was significantly higher at 100% PPO with EMS. No statistical differences were found for heart rate, pH, and Po2 between the tested cycling modes. The main findings of this study are greater metabolic changes (lactate, respiratory exchange ratio, BE, (Equation is included in full-text article.), Pco2) during cycling with EMS compared with normal cycling independent of frequency, mainly visible at higher work rates. Because metabolic alterations are important for the induction of cellular signaling cascades and adaptations, these results lead to the hypothesis that applied EMS stimulations during cycling exercise might be an enhancing stimulus for skeletal muscle metabolism and related adaptations. Thus, superimposed EMS application during cycling could be beneficial to aerobic performance enhancements in athletes and in patients who cannot perform high workloads. However, the higher demand on skeletal muscles involved must be considered.
2. Design and Implementation of 3D Model Database for General-Purpose 3D GIS
Institute of Scientific and Technical Information of China (English)
XU Weiping; ZHU Qing; DU Zhiqiang; ZHANG Yeting
2010-01-01
To improve the reusability of three-dimensional (3D) models and simplify the complexity of natural scene reconstruction, this paper presents a 3D model database for universal 3D GIS. After the introduction of its extensible function architecture,accompanied by the conclusion of implicit spatial-temporal hierarchy of models in any reconstructed scene of 3D GIS for general purpose, several key issues are discussed in detail, such as the storage and management of 3D models and related retrieval and load method, as well as the interfaces for further on-demand development. Finally, the validity and feasibility of this model database are proved through its application in the development of 3D visualization system of railway operation.
3. 3D Hilbert Space Filling Curves in 3D City Modeling for Faster Spatial Queries
DEFF Research Database (Denmark)
Ujang, Uznir; Antón Castro, Francesc/François; Azri, Suhaibah;
2014-01-01
are presented in this paper. The advantages of implementing space-filling curves in 3D city modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a sub-interval of the ([0,1]) interval to the corresponding...... method, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban...... web standards. However, these 3D city models consume much more storage compared to two dimensional (2 D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access...
4. X3d2pov. Traductor of X3D to POV-Ray
Directory of Open Access Journals (Sweden)
Andrea Castellanos Mendoza
2011-01-01
Full Text Available High-quality and low-quality interactive graphics represent two different approaches to computer graphics’ 3D object representation. The former is mainly used to produce high computational cost movie animation. The latter is used for producing interactive scenes as part of virtual reality environments. Many file format specifications have appeared to satisfy underlying model needs; POV-ray (persistence of vision is an open source specification for rendering photorealistic images with the ray tracer algorithm and X3D (extendable 3D as the VRML successor standard for producing web virtual-reality environments written in XML. X3D2POV has been introduced to render high-quality images from an X3D scene specification; it is a grammar translator tool from X3D code to POV-ray code.
5. 3D scene reconstruction based on 3D laser point cloud combining UAV images
Science.gov (United States)
Liu, Huiyun; Yan, Yangyang; Zhang, Xitong; Wu, Zhenzhen
2016-03-01
It is a big challenge capturing and modeling 3D information of the built environment. A number of techniques and technologies are now in use. These include GPS, and photogrammetric application and also remote sensing applications. The experiment uses multi-source data fusion technology for 3D scene reconstruction based on the principle of 3D laser scanning technology, which uses the laser point cloud data as the basis and Digital Ortho-photo Map as an auxiliary, uses 3DsMAX software as a basic tool for building three-dimensional scene reconstruction. The article includes data acquisition, data preprocessing, 3D scene construction. The results show that the 3D scene has better truthfulness, and the accuracy of the scene meet the need of 3D scene construction.
6. 3D-skannauksen hyödyntäminen 3D-tulostuksessa
OpenAIRE
Seppälä, Mikko
2016-01-01
Opinnäytetyössä tutustuttiin 3D-skannaus- ja 3D-tulostusteknologioihin. Työssä käytiin läpi erilaiset 3D-tulostusmenetelmät ja esiteltiin erilaisia 3D-skannausmenetelmiä. Lisäksi käytiin läpi 3D-skannaus- ja 3D-tulostusprosessi. Tavoitteena opinnäytetyössä oli tutkia, kuinka nämä kaksi teknologiaa toimivat yhdessä. Tarkoituksena oli käydä läpi prosessi, jossa fyysinen kappale skannattiin digitaaliseen muotoon, jonka jälkeen se voidaan tulostaa uudeksi fyysiseksi kappaleeksi. Lisäksi tarko...
7. Coloring and Guarding Arrangements
CERN Document Server
Bose, Prosenjit; Collette, Sébastien; Hurtado, Ferran; Korman, Matias; Langerman, Stefan; Taslakian, Perouz
2012-01-01
Given an arrangement of lines in the plane, what is the minimum number $c$ of colors required to color the lines so that no cell of the arrangement is monochromatic? In this paper we give bounds on the number c both for the above question, as well as some of its variations. We redefine these problems as geometric hypergraph coloring problems. If we define $\\Hlinecell$ as the hypergraph where vertices are lines and edges represent cells of the arrangement, the answer to the above question is equal to the chromatic number of this hypergraph. We prove that this chromatic number is between $\\Omega (\\log n / \\log\\log n)$. and $O(\\sqrt{n})$. Similarly, we give bounds on the minimum size of a subset $S$ of the intersections of the lines in $\\mathcal{A}$ such that every cell is bounded by at least one of the vertices in $S$. This may be seen as a problem on guarding cells with vertices when the lines act as obstacles. The problem can also be defined as the minimum vertex cover problem in the hypergraph $\\Hvertexcell$...
8. 3D Modeling Engine Representation Summary Report
Energy Technology Data Exchange (ETDEWEB)
Steven Prescott; Ramprasad Sampath; Curtis Smith; Timothy Yang
2014-09-01
Computers have been used for 3D modeling and simulation, but only recently have computational resources been able to give realistic results in a reasonable time frame for large complex models. This summary report addressed the methods, techniques, and resources used to develop a 3D modeling engine to represent risk analysis simulation for advanced small modular reactor structures and components. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.
9. Multifractal modelling and 3D lacunarity analysis
Energy Technology Data Exchange (ETDEWEB)
Hanen, Akkari, E-mail: [email protected] [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Imen, Bhouri, E-mail: [email protected] [Unite de recherche ondelettes et multifractals, Faculte des sciences (Tunisia); Asma, Ben Abdallah, E-mail: [email protected] [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Patrick, Dubois, E-mail: [email protected] [INSERM, U 703, Lille (France); Hedi, Bedoui Mohamed, E-mail: [email protected] [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia)
2009-09-28
This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.
10. Multifractal modelling and 3D lacunarity analysis
Science.gov (United States)
Hanen, Akkari; Imen, Bhouri; Asma, Ben Abdallah; Patrick, Dubois; Hédi, Bedoui Mohamed
2009-09-01
This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the “Relative Differential Box Counting” was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.
11. Body Language Advanced 3D Character Rigging
CERN Document Server
Allen, Eric; Fong, Jared; Sidwell, Adam G
2011-01-01
Whether you're a professional Character TD or just like to create 3D characters, this detailed guide reveals the techniques you need to create sophisticated 3D character rigs that range from basic to breathtaking. Packed with step-by-step instructions and full-color illustrations, Body Language walks you through rigging techniques for all the body parts to help you create realistic and believable movements in every character you design. You'll learn advanced rigging concepts that involve MEL scripting and advanced deformation techniques and even how to set up a character pipeline.
12. 3-D Reconstruction From Satellite Images
DEFF Research Database (Denmark)
Denver, Troelz
1999-01-01
The aim of this project has been to implement a software system, that is able to create a 3-D reconstruction from two or more 2-D photographic images made from different positions. The height is determined from the disparity difference of the images. The general purpose of the system is mapping o......, where various methods have been tested in order to optimize the performance. The match results are used in the reconstruction part to establish a 3-D digital representation and finally, different presentation forms are discussed....
13. Local orientation measurements in 3D
DEFF Research Database (Denmark)
Juul Jensen, D.
2005-01-01
The 3 Dimensional X-Ray Diffraction (3DXRD) method is presented and its potentials illustrated by examples. The 3DXRD method is based on diffraction of high energy X-rays and allows fast and nondestructive 3D characterization of the local distribution of crystallographic orientations in the bulk....... The spatial resolution is about 1x5x5 mu m but diffraction from microstructural elements as small as 100 nm may be monitored within suitable samples. As examples of the use of the 3DXRD method, it is chosen to present results for complete 3D characterization of grain structures, in-situ "filming...
14. The Galicia 3D experiment: an Introduction.
Science.gov (United States)
Reston, Timothy; Martinez Loriente, Sara; Holroyd, Luke; Merry, Tobias; Sawyer, Dale; Morgan, Julia; Jordan, Brian; Tesi Sanjurjo, Mari; Alexanian, Ara; Shillington, Donna; Gibson, James; Minshull, Tim; Karplus, Marianne; Bayracki, Gaye; Davy, Richard; Klaeschen, Dirk; Papenberg, Cord; Ranero, Cesar; Perez-Gussinye, Marta; Martinez, Miguel
2014-05-01
In June and July 2013, scientists from 8 institutions took part in the Galicia 3D seismic experiment, the first ever crustal -scale academic 3D MCS survey over a rifted margin. The aim was to determine the 3D structure of a critical portion of the west Galicia rifted margin. At this margin, well-defined tilted fault blocks, bound by west-dipping faults and capped by synrift sediments are underlain by a bright reflection, undulating on time sections, termed the S reflector and thought to represent a major detachment fault of some kind. Moving west, the crust thins to zero thickness and mantle is unroofed, as evidence by the "Peridotite Ridge" first reported at this margin, but since observed at many other magma-poor margins. By imaging such a margin in detail, the experiment aimed to resolve the processes controlling crustal thinning and mantle unroofing at a type example magma poor margin. The experiment set out to collect several key datasets: a 3D seismic reflection volume measuring ~20x64km and extending down to ~14s TWT, a 3D ocean bottom seismometer dataset suitable for full wavefield inversion (the recording of the complete 3D seismic shots by 70 ocean bottom instruments), the "mirror imaging" of the crust using the same grid of OBS, a single 2D combined reflection/refraction profile extending to the west to determine the transition from unroofed mantle to true oceanic crust, and the seismic imaging of the water column, calibrated by regular deployment of XBTs to measure the temperature structure of the water column. We collected 1280 km2 of seismic reflection data, consisting of 136533 shots recorded on 1920 channels, producing 260 million seismic traces, each ~ 14s long. This adds up to ~ 8 terabytes of data, representing, we believe, the largest ever academic 3D MCS survey in terms of both the area covered and the volume of data. The OBS deployment was the largest ever within an academic 3D survey.
15. 3D Membrane Imaging and Porosity Visualization
KAUST Repository
Sundaramoorthi, Ganesh
2016-03-03
Ultrafiltration asymmetric porous membranes were imaged by two microscopy methods, which allow 3D reconstruction: Focused Ion Beam and Serial Block Face Scanning Electron Microscopy. A new algorithm was proposed to evaluate porosity and average pore size in different layers orthogonal and parallel to the membrane surface. The 3D-reconstruction enabled additionally the visualization of pore interconnectivity in different parts of the membrane. The method was demonstrated for a block copolymer porous membrane and can be extended to other membranes with application in ultrafiltration, supports for forward osmosis, etc, offering a complete view of the transport paths in the membrane.
16. Factorization of the 3d superconformal index
CERN Document Server
Hwang, Chiung; Park, Jaemo
2012-01-01
We prove that 3d superconformal index for general $\\mathcal N=2$ U(N) gauge group with fundamentals and anti-fundmentals with/without Chern-Simons terms is factorized into vortex and anti-vortex partition function. We show that for simple cases, 3d vortex partition function coincides with a suitable topological open string partition function. We provide much more elegant derivation at the index level for $\\mathcal N=2$ Seiberg-like dualities of unitary gauge groups with fundamantal matters and $\\mathcal N=4$ mirror symmetry
17. SURVEY AND ANALYSIS OF 3D STEGANOGRAPHY
Directory of Open Access Journals (Sweden)
K .LAKSHMI
2011-01-01
Full Text Available Steganography is the science that involves communicating secret data in an appropriate multimedia carrier, eg., images, audio, and video files. The remarkable growth in computational power, increase in current security approaches and techniques are often used together to ensures security of the secret message. Steganography’s ultimate objectives, which are capacity and invisibility, are the main factors that separate it from related techniques. In this paper we focus on 3D models of steganography and conclude with some review analysis of high capacity data hiding and low-distortion 3D models.
18. Immersive 3D geovisualisation in higher education
Science.gov (United States)
Philips, Andrea; Walz, Ariane; Bergner, Andreas; Graeff, Thomas; Heistermann, Maik; Kienzler, Sarah; Korup, Oliver; Lipp, Torsten; Schwanghart, Wolfgang; Zeilinger, Gerold
2014-05-01
Through geovisualisation we explore spatial data, we analyse it towards a specific questions, we synthesise results, and we present and communicate them to a specific audience (MacEachren & Kraak 1997). After centuries of paper maps, the means to represent and visualise our physical environment and its abstract qualities have changed dramatically since the 1990s - and accordingly the methods how to use geovisualisation in teaching. Whereas some people might still consider the traditional classroom as ideal setting for teaching and learning geographic relationships and its mapping, we used a 3D CAVE (computer-animated virtual environment) as environment for a problem-oriented learning project called "GEOSimulator". Focussing on this project, we empirically investigated, if such a technological advance like the CAVE make 3D visualisation, including 3D geovisualisation, not only an important tool for businesses (Abulrub et al. 2012) and for the public (Wissen et al. 2008), but also for educational purposes, for which it had hardly been used yet. The 3D CAVE is a three-sided visualisation platform, that allows for immersive and stereoscopic visualisation of observed and simulated spatial data. We examined the benefits of immersive 3D visualisation for geographic research and education and synthesized three fundamental technology-based visual aspects: First, the conception and comprehension of space and location does not need to be generated, but is instantaneously and intuitively present through stereoscopy. Second, optical immersion into virtual reality strengthens this spatial perception which is in particular important for complex 3D geometries. And third, a significant benefit is interactivity, which is enhanced through immersion and allows for multi-discursive and dynamic data exploration and knowledge transfer. Based on our problem-oriented learning project, which concentrates on a case study on flood risk management at the Wilde Weisseritz in Germany, a river
19. The Local Universe: Galaxies in 3D
CERN Document Server
Koribalski, B S
2016-01-01
Here I present results from individual galaxy studies and galaxy surveys in the Local Universe with particular emphasis on the spatially resolved properties of neutral hydrogen gas. The 3D nature of the data allows detailed studies of the galaxy morphology and kinematics, their relation to local and global star formation as well as galaxy environments. I use new 3D visualisation tools to present multi-wavelength data, aided by tilted-ring models of the warped galaxy disks. Many of the algorithms and tools currently under development are essential for the exploration of upcoming large survey data, but are also highly beneficial for the analysis of current galaxy surveys.
20. Tekstiilit 3d-mallinnuksessa ja -animaatiossa
OpenAIRE
Lahti, Toni
2007-01-01
Opinnäytetyön tarkoituksena oli tutkia tekstiilien 3D-mallinnusta ja animaatiota. Hahmon vaatetus on työn pääroolissa ja esimerkit liittyvät useimmiten vaatekappaleisiin. Vaatteet ovat mielenkiintoisimpia ja vaikeimmin toteutettavia tekstiilejä.; Alkuun täytyi tutustua tekstiilien luonteeseen. Tekstiilien erilaiset rakenteet vaikuttavat siihen kuinka tekstiili käyttäytyy. Tämän takia työssä esitellään kudotun ja neulotun tekstiilin valmistus ja niiden perusrakenteet.; 3D-mallinnettujen tekst...
1. Building 3D models with modo 701
CERN Document Server
García, Juan Jiménez
2013-01-01
The book will focus on creating a sample application throughout the book, building gradually from chapter to chapter.If you are new to the 3D world, this is the key to getting started with a modern software in the modern visualization industry. Only minimal previous knowledge is needed.If you have some previous knowledge about 3D content creation, you will find useful tricks that will differentiate the learning experience from a typical user manual from this, a practical guide concerning the most common problems and situations and how to solve them.
2. Delft3D turbine turbulence module
Energy Technology Data Exchange (ETDEWEB)
2016-04-18
The DOE has funded Sandia National Labs (SNL) to develop an open-source modeling tool to guide the design and layout of marine hydrokinetic (MHK) arrays to maximize power production while minimizing environmental effects. This modeling framework simulates flows through and around a MHK arrays while quantifying environmental responses. As an augmented version of the Dutch company, Deltares’s, environmental hydrodynamics code, Delft3D, SNL-Delft3D includes a new module that simulates energy conversion (momentum withdrawal) by MHK devices with commensurate changes in the turbulent kinetic energy and its dissipation rate.
3. Scalable 3D GIS environment managed by 3D-XML-based modeling
Science.gov (United States)
Shi, Beiqi; Rui, Jianxun; Chen, Neng
2008-10-01
Nowadays, the namely 3D GIS technologies become a key factor in establishing and maintaining large-scale 3D geoinformation services. However, with the rapidly increasing size and complexity of the 3D models being acquired, a pressing needed for suitable data management solutions has become apparent. This paper outlines that storage and exchange of geospatial data between databases and different front ends like 3D models, GIS or internet browsers require a standardized format which is capable to represent instances of 3D GIS models, to minimize loss of information during data transfer and to reduce interface development efforts. After a review of previous methods for spatial 3D data management, a universal lightweight XML-based format for quick and easy sharing of 3D GIS data is presented. 3D data management based on XML is a solution meeting the requirements as stated, which can provide an efficient means for opening a new standard way to create an arbitrary data structure and share it over the Internet. To manage reality-based 3D models, this paper uses 3DXML produced by Dassault Systemes. 3DXML uses opening XML schemas to communicate product geometry, structure and graphical display properties. It can be read, written and enriched by standard tools; and allows users to add extensions based on their own specific requirements. The paper concludes with the presentation of projects from application areas which will benefit from the functionality presented above.
4. PB3D: A new code for edge 3-D ideal linear peeling-ballooning stability
Science.gov (United States)
Weyens, T.; Sánchez, R.; Huijsmans, G.; Loarte, A.; García, L.
2017-02-01
A new numerical code PB3D (Peeling-Ballooning in 3-D) is presented. It implements and solves the intermediate-to-high-n ideal linear magnetohydrodynamic stability theory extended to full edge 3-D magnetic toroidal configurations in previous work [1]. The features that make PB3D unique are the assumptions on the perturbation structure through intermediate-to-high mode numbers n in general 3-D configurations, while allowing for displacement of the plasma edge. This makes PB3D capable of very efficient calculations of the full 3-D stability for the output of multiple equilibrium codes. As first verification, it is checked that results from the stability code MISHKA [2], which considers axisymmetric equilibrium configurations, are accurately reproduced, and these are then successfully extended to 3-D configurations, through comparison with COBRA [3], as well as using checks on physical consistency. The non-intuitive 3-D results presented serve as a tentative first proof of the capabilities of the code.
5. MRS3D: 3D Spherical Wavelet Transform on the Sphere
Science.gov (United States)
Lanusse, F.; Rassat, A.; Starck, J.-L.
2011-12-01
Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D Spherical Fourier-Bessel (SFB) analysis is natural. Wavelets are particularly well-suited to the analysis and denoising of cosmological data, but a spherical 3D isotropic wavelet transform does not currently exist to analyse spherical 3D data. We present a new fast Discrete Spherical Fourier-Bessel Transform (DSFBT) based on both a discrete Bessel Transform and the HEALPIX angular pixelisation scheme. We tested the 3D wavelet transform and as a toy-application, applied a denoising algorithm in wavelet space to the Virgo large box cosmological simulations and found we can successfully remove noise without much loss to the large scale structure. The new spherical 3D isotropic wavelet transform, called MRS3D, is ideally suited to analysing and denoising future 3D spherical cosmological surveys; it uses a novel discrete spherical Fourier-Bessel Transform. MRS3D is based on two packages, IDL and Healpix and can be used only if these two packages have been installed.
6. Innovations in 3D printing: a 3D overview from optics to organs.
Science.gov (United States)
Schubert, Carl; van Langeveld, Mark C; Donoso, Larry A
2014-02-01
3D printing is a method of manufacturing in which materials, such as plastic or metal, are deposited onto one another in layers to produce a three dimensional object, such as a pair of eye glasses or other 3D objects. This process contrasts with traditional ink-based printers which produce a two dimensional object (ink on paper). To date, 3D printing has primarily been used in engineering to create engineering prototypes. However, recent advances in printing materials have now enabled 3D printers to make objects that are comparable with traditionally manufactured items. In contrast with conventional printers, 3D printing has the potential to enable mass customisation of goods on a large scale and has relevance in medicine including ophthalmology. 3D printing has already been proved viable in several medical applications including the manufacture of eyeglasses, custom prosthetic devices and dental implants. In this review, we discuss the potential for 3D printing to revolutionise manufacturing in the same way as the printing press revolutionised conventional printing. The applications and limitations of 3D printing are discussed; the production process is demonstrated by producing a set of eyeglass frames from 3D blueprints.
7. The EISCAT_3D Science Case
Science.gov (United States)
Tjulin, A.; Mann, I.; McCrea, I.; Aikio, A. T.
2013-05-01
EISCAT_3D will be a world-leading international research infrastructure using the incoherent scatter technique to study the atmosphere in the Fenno-Scandinavian Arctic and to investigate how the Earth's atmosphere is coupled to space. The EISCAT_3D phased-array multistatic radar system will be operated by EISCAT Scientific Association and thus be an integral part of an organisation that has successfully been running incoherent scatter radars for more than thirty years. The baseline design of the radar system contains a core site with transmitting and receiving capabilities located close to the intersection of the Swedish, Norwegian and Finnish borders and five receiving sites located within 50 to 250 km from the core. The EISCAT_3D project is currently in its Preparatory Phase and can smoothly transit into implementation in 2014, provided sufficient funding. Construction can start 2016 and first operations in 2018. The EISCAT_3D Science Case is prepared as part of the Preparatory Phase. It is regularly updated with annual new releases, and it aims at being a common document for the whole future EISCAT_3D user community. The areas covered by the Science Case are atmospheric physics and global change; space and plasma physics; solar system research; space weather and service applications; and radar techniques, new methods for coding and analysis. Two of the aims for EISCAT_3D are to understand the ways natural variability in the upper atmosphere, imposed by the Sun-Earth system, can influence the middle and lower atmosphere, and to improve the predictivity of atmospheric models by providing higher resolution observations to replace the current parametrised input. Observations by EISCAT_3D will also be used to monitor the direct effects from the Sun on the ionosphere-atmosphere system and those caused by solar wind magnetosphere-ionosphere interaction. In addition, EISCAT_3D will be used for remote sensing the large-scale behaviour of the magnetosphere from its
8. Acquiring 3D indoor environments with variability and repetition
KAUST Repository
Kim, Youngmin
2012-11-01
Large-scale acquisition of exterior urban environments is by now a well-established technology, supporting many applications in search, navigation, and commerce. The same is, however, not the case for indoor environments, where access is often restricted and the spaces are cluttered. Further, such environments typically contain a high density of repeated objects (e.g., tables, chairs, monitors, etc.) in regular or non-regular arrangements with significant pose variations and articulations. In this paper, we exploit the special structure of indoor environments to accelerate their 3D acquisition and recognition with a low-end handheld scanner. Our approach runs in two phases: (i) a learning phase wherein we acquire 3D models of frequently occurring objects and capture their variability modes from only a few scans, and (ii) a recognition phase wherein from a single scan of a new area, we identify previously seen objects but in different poses and locations at an average recognition time of 200ms/model. We evaluate the robustness and limits of the proposed recognition system using a range of synthetic and real world scans under challenging settings. © 2012 ACM.
9. Risk Factors of Superimposed Preeclampsia in Women with Essential Chronic Hypertension Treated before Pregnancy
OpenAIRE
2013-01-01
OBJECTIVE: To determine risk factors of superimposed preeclampsia in women with essential chronic hypertension receiving antihypertensive therapy prior to conception. METHODS: A retrospective study of 211 patients that analyzed risk factors of superimposed preeclampsia at first prenatal visit. Variables with a p
10. 16 CFR 300.27 - Wool products containing superimposed or added fibers.
Science.gov (United States)
2010-01-01
... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Wool products containing superimposed or added fibers. 300.27 Section 300.27 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULES AND REGULATIONS UNDER THE WOOL PRODUCTS LABELING ACT OF 1939 Labeling § 300.27 Wool products containing superimposed...
11. Structure and magnetic exchange in heterometallic 3d-3d transition metal triethanolamine clusters.
Science.gov (United States)
Langley, Stuart K; Chilton, Nicholas F; Moubaraki, Boujemaa; Murray, Keith S
2012-01-21
Synthetic methods are described that have resulted in the formation of seven heterometallic complexes, all of which contain partially deprotonated forms of the ligand triethanolamine (teaH(3)). These compounds are [Mn(III)(4)Co(III)(2)Co(II)(2)O(2)(teaH(2))(2)(teaH)(0.82)(dea)(3.18)(O(2)CMe)(2)(OMe)(2)](BF(4))(2)(O(2)CMe)(2)·3.18MeOH·H(2)O (1), [Mn(II)(2)Mn(III)(2)Co(III)(2)(teaH)(4)(OMe)(2)(acac)(4)](NO(3))(2)·2MeOH (2), [Mn(III)(2)Ni(II)(4)(teaH)(4)(O(2)CMe)(6)]·2MeCN (3), [Mn(III)(2)Co(II)(2)(teaH)(2)(sal)(2)(acac)(2)(MeOH)(2)]·2MeOH (4), [Mn(II)(2)Fe(III)(2)(teaH)(2)(paa)(4)](NO(3))(2)·2MeOH·CH(2)Cl(2) (5), [Mn(II)Mn(III)(2)Co(III)(2)O(teaH)(2)(dea)(Iso)(OMe)(F)(2)(Phen)(2)](BF(4))(NO(3))·3MeOH (6) and [Mn(II)(2)Mn(III)Co(III)(2)(OH)(teaH)(3)(teaH(2))(acac)(3)](NO(3))(2)·3CH(2)Cl(2) (7). All of the compounds contain manganese, combined with 3d transition metal ions such as Fe, Co and Ni. The crystal structures are described and examples of 'rods', tetranuclear 'butterfly' and 'triangular' Mn(3) cluster motifs, flanked in some cases by diamagnetic cobalt(III) centres, are presented. Detailed DC and AC magnetic susceptibility and magnetization studies, combined with spin Hamiltonian analysis, have yielded J values and identified the spin ground states. In most cases, the energies of the low-lying excited states have also been obtained. The features of note include the 'inverse butterfly' spin arrangement in 2, 4 and 5. A S = 5/2 ground state occurs, for the first time, in the Mn(III)(2)Mn(II) triangular moiety within 6, the many other reported [Mn(3)O](6+) examples having S = ½ or 3/2 ground states. Compound 7 provides the first example of a Mn(II)(2)Mn(III) triangle, here within a pentanuclear Mn(3)Co(2) cluster.
12. 3D Cell Culture in Alginate Hydrogels
Directory of Open Access Journals (Sweden)
Therese Andersen
2015-03-01
Full Text Available This review compiles information regarding the use of alginate, and in particular alginate hydrogels, in culturing cells in 3D. Knowledge of alginate chemical structure and functionality are shown to be important parameters in design of alginate-based matrices for cell culture. Gel elasticity as well as hydrogel stability can be impacted by the type of alginate used, its concentration, the choice of gelation technique (ionic or covalent, and divalent cation chosen as the gel inducing ion. The use of peptide-coupled alginate can control cell–matrix interactions. Gelation of alginate with concomitant immobilization of cells can take various forms. Droplets or beads have been utilized since the 1980s for immobilizing cells. Newer matrices such as macroporous scaffolds are now entering the 3D cell culture product market. Finally, delayed gelling, injectable, alginate systems show utility in the translation of in vitro cell culture to in vivo tissue engineering applications. Alginate has a history and a future in 3D cell culture. Historically, cells were encapsulated in alginate droplets cross-linked with calcium for the development of artificial organs. Now, several commercial products based on alginate are being used as 3D cell culture systems that also demonstrate the possibility of replacing or regenerating tissue.
13. MIM in 3D: dream or reality?
NARCIS (Netherlands)
Klootwijk, J.H.; Jinesh, K.B.; Roozeboom, F.
2011-01-01
Last decades great effort has been put in the development of 3D capacitors. These capacitors are used for RF decoupling and should therefore have a high capacitance density associated with a sufficient breakdown voltage. Increased capacitance densities have been achieved by exploring the use of the
14. 3D scanning particle tracking velocimetry
Energy Technology Data Exchange (ETDEWEB)
Hoyer, Klaus; Holzner, Markus; Guala, Michele; Liberzon, Alexander; Kinzelbach, Wolfgang [Swiss Federal Institut of Technology Zurich, Institut fuer Hydromechanik und Wasserwirtschaft, Zuerich (Switzerland); Luethi, Beat [Risoe National Laboratory, Roskilde (Denmark)
2005-11-01
In this article, we present an experimental setup and data processing schemes for 3D scanning particle tracking velocimetry (SPTV), which expands on the classical 3D particle tracking velocimetry (PTV) through changes in the illumination, image acquisition and analysis. 3D PTV is a flexible flow measurement technique based on the processing of stereoscopic images of flow tracer particles. The technique allows obtaining Lagrangian flow information directly from measured 3D trajectories of individual particles. While for a classical PTV the entire region of interest is simultaneously illuminated and recorded, in SPTV the flow field is recorded by sequential tomographic high-speed imaging of the region of interest. The advantage of the presented method is a considerable increase in maximum feasible seeding density. Results are shown for an experiment in homogenous turbulence and compared with PTV. SPTV yielded an average 3,500 tracked particles per time step, which implies a significant enhancement of the spatial resolution for Lagrangian flow measurements. (orig.)
15. Embedding 3D into multipurpose cadastre
NARCIS (Netherlands)
Rahman, A.A.; Hua, T.C.; Van Oosterom, P.J.M.
2011-01-01
There is no doubt that the cadastral map provides a useful entrance to information in a land parcel based information system. However, such information system could be made more meaningful and useful if it can be extended for multiple usages with multi data layers, and in three-dimensions (3D). Curr
16. 3D microstructuring of biodegradable polymers
DEFF Research Database (Denmark)
Nagstrup, Johan; Keller, Stephan Sylvest; Almdal, Kristoffer
2011-01-01
Biopolymer films with a thickness of 100μm are prepared using spin coating technique with solutions consisting of 25wt.% polycaprolactone or poly-l-lactide in dichloromethane. SU-8 stamps are fabricated using three photolithography steps. The stamps are used to emboss 3D microstructures...
17. 3D Video Compression and Transmission
DEFF Research Database (Denmark)
Zamarin, Marco; Forchhammer, Søren
In this short paper we provide a brief introduction to 3D and multi-view video technologies - like three-dimensional television and free-viewpoint video - focusing on the aspects related to data compression and transmission. Geometric information represented by depth maps is introduced as well...
18. 3D Printed Terahertz Focusing Grating Couplers
Science.gov (United States)
Jahn, David; Weidenbach, Marcel; Lehr, Jannik; Becker, Leonard; Beltrán-Mejía, Felipe; Busch, Stefan F.; Balzer, Jan C.; Koch, Martin
2017-02-01
We have designed, constructed and characterized a grating that focuses electromagnetic radiation at specific frequencies out of a dielectric waveguide. A simple theoretical model predicts the focusing behaviour of these chirped gratings, along with numerical results that support our assumptions and improved the grating geometry. The leaky waveguide was 3D printed and characterized at 120 GHz demonstrating its potential for manipulating terahertz waves.
19. 3D virtual table in anatomy education
DEFF Research Database (Denmark)
Dahl, Mads Ronald; Simonsen, Eivind Ortind
The ‘Anatomage’ is a 3D virtual human anatomy table, with touchscreen functionality, where it is possible to upload CT-scans and digital. Learning the human anatomy terminology requires time, a very good memory, anatomy atlas, books and lectures. Learning the 3 dimensional structure, connections...
20. Holographic 3D tracking of microscopic tools
DEFF Research Database (Denmark)
Glückstad, Jesper; Villangca, Mark Jayson; Bañas, Andrew Rafael
2015-01-01
We originally proposed and experimentally demonstrated the targeted-light delivery capability of so-called Wave-guided Optical Waveguides (WOWs) three years ago. As these WOWs are maneuvered in 3D space, it is important to maintain efficient light coupling through their integrated waveguide struc...
1. 3D gender recognition using cognitive modeling
DEFF Research Database (Denmark)
Fagertun, Jens; Andersen, Tobias; Hansen, Thomas
2013-01-01
We use 3D scans of human faces and cognitive modeling to estimate the “gender strength”. The “gender strength” is a continuous class variable of the gender, superseding the traditional binary class labeling. To visualize some of the visual trends humans use when performing gender classification, ...
2. Techniques and architectures for 3D interaction
NARCIS (Netherlands)
De Haan, G.
2009-01-01
Spatial scientific datasets are all around us, and 3D visualization is a powerful tool to explore details and structures within them. When dealing with complex spatial structures, interactive Virtual Reality (VR) systems can potentially improve exploration over desktop-based systems. However, from p
3. Infra Red 3D Computer Mouse
DEFF Research Database (Denmark)
Harbo, Anders La-Cour; Stoustrup, Jakob
2000-01-01
of bandwidth, the signals are designed by means of the wavelet and the Rudin-Shapiro transforms. This also allows for easy separation of simultaneously made measurements. The measured intensities are converted to an 3D position by a neural net. The principle also applies to other applications, for instance...
4. Planetary Torque in 3D Isentropic Disks
Science.gov (United States)
Fung, Jeffrey; Masset, Frédéric; Lega, Elena; Velasco, David
2017-03-01
Planetary migration is inherently a three-dimensional (3D) problem, because Earth-size planetary cores are deeply embedded in protoplanetary disks. Simulations of these 3D disks remain challenging due to the steep resolution requirements. Using two different hydrodynamics codes, FARGO3D and PEnGUIn, we simulate disk–planet interaction for a one to five Earth-mass planet embedded in an isentropic disk. We measure the torque on the planet and ensure that the measurements are converged both in resolution and between the two codes. We find that the torque is independent of the smoothing length of the planet’s potential (r s), and that it has a weak dependence on the adiabatic index of the gaseous disk (γ). The torque values correspond to an inward migration rate qualitatively similar to previous linear calculations. We perform additional simulations with explicit radiative transfer using FARGOCA, and again find agreement between 3D simulations and existing torque formulae. We also present the flow pattern around the planets that show active flow is present within the planet’s Hill sphere, and meridional vortices are shed downstream. The vertical flow speed near the planet is faster for a smaller r s or γ, up to supersonic speeds for the smallest r s and γ in our study.
5. Automated analysis of 3D echocardiography
NARCIS (Netherlands)
Stralen, Marijn van
2009-01-01
In this thesis we aim at automating the analysis of 3D echocardiography, mainly targeting the functional analysis of the left ventricle. Manual analysis of these data is cumbersome, time-consuming and is associated with inter-observer and inter-institutional variability. Methods for reconstruction o
6. Introduction to 3D Graphics through Excel
Science.gov (United States)
Benacka, Jan
2013-01-01
The article presents a method of explaining the principles of 3D graphics through making a revolvable and sizable orthographic parallel projection of cuboid in Excel. No programming is used. The method was tried in fourteen 90 minute lessons with 181 participants, which were Informatics teachers, undergraduates of Applied Informatics and gymnasium…
7. Feasibility of 3D harmonic contrast imaging
NARCIS (Netherlands)
Voormolen, M.M.; Bouakaz, A.; Krenning, B.J.; Lancée, C.; ten Cate, F.; de Jong, N.
2004-01-01
Improved endocardial border delineation with the application of contrast agents should allow for less complex and faster tracing algorithms for left ventricular volume analysis. We developed a fast rotating phased array transducer for 3D imaging of the heart with harmonic capabilities making it
8. Planetary Torque in 3D Isentropic Disks
CERN Document Server
Fung, Jeffrey; Lega, Elena; Velasco, David
2016-01-01
Planet migration is inherently a three-dimensional (3D) problem, because Earth-size planetary cores are deeply embedded in protoplanetary disks. Simulations of these 3D disks remain challenging due to the steep requirement in resolution. Using two different hydrodynamics code, FARGO3D and PEnGUIn, we simulate disk-planet interaction for a 1 to 5 Earth-mass planet embedded in an isentropic disk. We measure the torque on the planet and ensure that the measurements are converged both in resolution and between the two codes. We find that the torque is independent of the smoothing length of the planet's potential ($r_{\\rm s}$), and that it has a weak dependence on the adiabatic index of the gaseous disk ($\\gamma$). The torque values correspond to an inward migration rate qualitatively similar to previous linear calculations. We perform additional simulations with explicit radiative transfer using FARGOCA, and again find agreement between 3D simulations and existing torque formulae. We also present the flow pattern...
9. Spacecraft 3D Augmented Reality Mobile App
Science.gov (United States)
Hussey, Kevin J.; Doronila, Paul R.; Kumanchik, Brian E.; Chan, Evan G.; Ellison, Douglas J.; Boeck, Andrea; Moore, Justin M.
2013-01-01
The Spacecraft 3D application allows users to learn about and interact with iconic NASA missions in a new and immersive way using common mobile devices. Using Augmented Reality (AR) techniques to project 3D renditions of the mission spacecraft into real-world surroundings, users can interact with and learn about Curiosity, GRAIL, Cassini, and Voyager. Additional updates on future missions, animations, and information will be ongoing. Using a printed AR Target and camera on a mobile device, users can get up close with these robotic explorers, see how some move, and learn about these engineering feats, which are used to expand knowledge and understanding about space. The software receives input from the mobile device's camera to recognize the presence of an AR marker in the camera's field of view. It then displays a 3D rendition of the selected spacecraft in the user's physical surroundings, on the mobile device's screen, while it tracks the device's movement in relation to the physical position of the spacecraft's 3D image on the AR marker.
10. 3-D GIS : Virtual London and beyond
Directory of Open Access Journals (Sweden)
Michael Batty
2006-10-01
Full Text Available In this paper, we outline how we have developed a series of technologies to enable detailed interactive 3-D Geographical Information Systems (GIS based models of cities to be created. Until relatively recently these models have been developed in Computer Aided Design (CAD software more often then in GIS. One of the main reasons was that ‘3-D GIS’ was often only 2.5-D under closer inspection. This is changing, and by straddling both technologies, and integrating others, we show how these models in turn enable planning information, statistics, pollution levels, sea level rises and much more to be visualised and analysed in the context of the 3-D city model. The client for ‘Virtual London’ is the Greater London Authority (GLA and their aim is to develop improved dissemination of planning information, which is explored. We then argue that virtual cities should go well beyond the traditional conceptions of 3-D GIS and CAD into virtual worlds and online design. But we also urge caution in pushing the digital message too far, showing how more conventional tangible media is always necessary in rooting such models in more realistic and familiar representations.
11. Constructing Arguments with 3-D Printed Models
Science.gov (United States)
McConnell, William; Dickerson, Daniel
2017-01-01
In this article, the authors describe a fourth-grade lesson where 3-D printing technologies were not only a stimulus for engagement but also served as a modeling tool providing meaningful learning opportunities. Specifically, fourth-grade students construct an argument that animals' external structures function to support survival in a particular…
12. 3D-Nanomachining using corner lithography
NARCIS (Netherlands)
Berenschot, Johan W.; Tas, Niels Roelof; Jansen, Henricus V.; Elwenspoek, Michael Curt
2008-01-01
We present a fabrication method to create 3D nano structures without the need for nano lithography. The method, named "corner lithography" is based on conformal deposition and subsequent isotropic thinning of a thin film. The material that remains in sharp concave corners is either used as a mask or
13. The New Realm of 3-D Vision
Science.gov (United States)
2002-01-01
Dimension Technologies Inc., developed a line of 2-D/3-D Liquid Crystal Display (LCD) screens, including a 15-inch model priced at consumer levels. DTI's family of flat panel LCD displays, called the Virtual Window(TM), provide real-time 3-D images without the use of glasses, head trackers, helmets, or other viewing aids. Most of the company initial 3-D display research was funded through NASA's Small Business Innovation Research (SBIR) program. The images on DTI's displays appear to leap off the screen and hang in space. The display accepts input from computers or stereo video sources, and can be switched from 3-D to full-resolution 2-D viewing with the push of a button. The Virtual Window displays have applications in data visualization, medicine, architecture, business, real estate, entertainment, and other research, design, military, and consumer applications. Displays are currently used for computer games, protein analysis, and surgical imaging. The technology greatly benefits the medical field, as surgical simulators are helping to increase the skills of surgical residents. Virtual Window(TM) is a trademark of Dimension Technologies Inc.
14. 3D Urban Visualization with LOD Techniques
Institute of Scientific and Technical Information of China (English)
2006-01-01
In 3D urban visualization, large data volumes related to buildings are a major factor that limits the delivery and browsing speed in a web-based computer system. This paper proposes a new approach based on the level of detail (LOD) technique advanced in 3D visualization in computer graphics. The key idea of LOD technique is to generalize details of object surfaces without losing details for delivery and displaying objects. This technique has been successfully used in visualizing one or a few multiple objects in films and other industries. However, applying the technique to 3D urban visualization requires an effective generalization method for urban buildings. Conventional two-dimensional (2D) generalization method at different scales provides a good generalization reference for 3D urban visualization. Yet, it is difficult to determine when and where to retrieve data for displaying buildings. To solve this problem, this paper defines an imaging scale point and image scale region for judging when and where to get the right data for visualization. The results show that the average response time of view transformations is much decreased.
15. Implementation of a 3D Virtual Drummer
NARCIS (Netherlands)
Magnenat-ThalmannThalmann, M.; Kragtwijk, M.; Nijholt, Antinus; Thalmann, D.; Zwiers, Jakob
2001-01-01
We describe a system for the automatic generation of a 3D animation of a drummer playing along with a given piece of music. The input, consisting of a sound wave, is analysed to determine which drums are struck at what moments. The Standard MIDI File format is used to store the recognised notes. Fro
16. Rubber Impact on 3D Textile Composites
Science.gov (United States)
Heimbs, Sebastian; Van Den Broucke, Björn; Duplessis Kergomard, Yann; Dau, Frederic; Malherbe, Benoit
2012-06-01
A low velocity impact study of aircraft tire rubber on 3D textile-reinforced composite plates was performed experimentally and numerically. In contrast to regular unidirectional composite laminates, no delaminations occur in such a 3D textile composite. Yarn decohesions, matrix cracks and yarn ruptures have been identified as the major damage mechanisms under impact load. An increase in the number of 3D warp yarns is proposed to improve the impact damage resistance. The characteristic of a rubber impact is the high amount of elastic energy stored in the impactor during impact, which was more than 90% of the initial kinetic energy. This large geometrical deformation of the rubber during impact leads to a less localised loading of the target structure and poses great challenges for the numerical modelling. A hyperelastic Mooney-Rivlin constitutive law was used in Abaqus/Explicit based on a step-by-step validation with static rubber compression tests and low velocity impact tests on aluminium plates. Simulation models of the textile weave were developed on the meso- and macro-scale. The final correlation between impact simulation results on 3D textile-reinforced composite plates and impact test data was promising, highlighting the potential of such numerical simulation tools.
17. Collaborative annotation of 3D crystallographic models.
Science.gov (United States)
Hunter, J; Henderson, M; Khan, I
2007-01-01
This paper describes the AnnoCryst system-a tool that was designed to enable authenticated collaborators to share online discussions about 3D crystallographic structures through the asynchronous attachment, storage, and retrieval of annotations. Annotations are personal comments, interpretations, questions, assessments, or references that can be attached to files, data, digital objects, or Web pages. The AnnoCryst system enables annotations to be attached to 3D crystallographic models retrieved from either private local repositories (e.g., Fedora) or public online databases (e.g., Protein Data Bank or Inorganic Crystal Structure Database) via a Web browser. The system uses the Jmol plugin for viewing and manipulating the 3D crystal structures but extends Jmol by providing an additional interface through which annotations can be created, attached, stored, searched, browsed, and retrieved. The annotations are stored on a standardized Web annotation server (Annotea), which has been extended to support 3D macromolecular structures. Finally, the system is embedded within a security framework that is capable of authenticating users and restricting access only to trusted colleagues.
18. Pyrolytic 3D Carbon Microelectrodes for Electrochemistry
DEFF Research Database (Denmark)
Hemanth, Suhith; Caviglia, Claudia; Amato, Letizia
2016-01-01
This work presents the fabrication and characterization of suspended three-dimensional (3D) pyrolytic carbon microelectrodes for electrochemical applications. For this purpose, an optimized process with multiple steps of UV photolithography with the negative tone photoresist SU-8 followed by pyro...
19. 3D MHD Flux emergence experiments
DEFF Research Database (Denmark)
Hood, A.W.; Archontis, V.; Mactaggart, David
2012-01-01
This paper reviews some of the many 3D numerical experiments of the emergence of magnetic fields from the solar interior and the subsequent interaction with the pre-existing coronal magnetic field. The models described here are idealised, in the sense that the internal energy equation only involves...
20. Angiogenic factors in superimposed preeclampsia: a longitudinal study of women with chronic hypertension during pregnancy.
Science.gov (United States)
Perni, Uma; Sison, Cristina; Sharma, Vijay; Helseth, Geri; Hawfield, Amret; Suthanthiran, Manikkam; August, Phyllis
2012-03-01
Imbalances in circulating angiogenic factors contribute to the pathogenesis of preeclampsia. To characterize levels of angiogenic factors in pregnant women with chronic hypertension, we prospectively followed 109 women and measured soluble fms-like tyrosine kinase 1 (sFlt1), soluble endoglin, and placental growth factor at 12, 20, 28, and 36 weeks' gestation and postpartum. Superimposed preeclampsia developed in 37 (34%) and was early onset (hypertension. We conclude that alterations in angiogenic factors are detectable before and at the time of clinical diagnosis of early onset superimposed preeclampsia, whereas alterations were observed only at the time of diagnosis in women with late-onset superimposed preeclampsia. Longitudinal measurements of angiogenic factors may help anticipate early onset superimposed preeclampsia and facilitate diagnosis of superimposed preeclampsia in women with chronic hypertension.
1. Uncertainty in 3D gel dosimetry
Science.gov (United States)
De Deene, Yves; Jirasek, Andrew
2015-01-01
Three-dimensional (3D) gel dosimetry has a unique role to play in safeguarding conformal radiotherapy treatments as the technique can cover the full treatment chain and provides the radiation oncologist with the integrated dose distribution in 3D. It can also be applied to benchmark new treatment strategies such as image guided and tracking radiotherapy techniques. A major obstacle that has hindered the wider dissemination of gel dosimetry in radiotherapy centres is a lack of confidence in the reliability of the measured dose distribution. Uncertainties in 3D dosimeters are attributed to both dosimeter properties and scanning performance. In polymer gel dosimetry with MRI readout, discrepancies in dose response of large polymer gel dosimeters versus small calibration phantoms have been reported which can lead to significant inaccuracies in the dose maps. The sources of error in polymer gel dosimetry with MRI readout are well understood and it has been demonstrated that with a carefully designed scanning protocol, the overall uncertainty in absolute dose that can currently be obtained falls within 5% on an individual voxel basis, for a minimum voxel size of 5 mm3. However, several research groups have chosen to use polymer gel dosimetry in a relative manner by normalizing the dose distribution towards an internal reference dose within the gel dosimeter phantom. 3D dosimetry with optical scanning has also been mostly applied in a relative way, although in principle absolute calibration is possible. As the optical absorption in 3D dosimeters is less dependent on temperature it can be expected that the achievable accuracy is higher with optical CT. The precision in optical scanning of 3D dosimeters depends to a large extend on the performance of the detector. 3D dosimetry with X-ray CT readout is a low contrast imaging modality for polymer gel dosimetry. Sources of error in x-ray CT polymer gel dosimetry (XCT) are currently under investigation and include inherent
2. Scoops3D: software to analyze 3D slope stability throughout a digital landscape
Science.gov (United States)
Reid, Mark E.; Christian, Sarah B.; Brien, Dianne L.; Henderson, Scott T.
2015-01-01
The computer program, Scoops3D, evaluates slope stability throughout a digital landscape represented by a digital elevation model (DEM). The program uses a three-dimensional (3D) method of columns approach to assess the stability of many (typically millions) potential landslides within a user-defined size range. For each potential landslide (or failure), Scoops3D assesses the stability of a rotational, spherical slip surface encompassing many DEM cells using a 3D version of either Bishop’s simplified method or the Ordinary (Fellenius) method of limit-equilibrium analysis. Scoops3D has several options for the user to systematically and efficiently search throughout an entire DEM, thereby incorporating the effects of complex surface topography. In a thorough search, each DEM cell is included in multiple potential failures, and Scoops3D records the lowest stability (factor of safety) for each DEM cell, as well as the size (volume or area) associated with each of these potential landslides. It also determines the least-stable potential failure for the entire DEM. The user has a variety of options for building a 3D domain, including layers or full 3D distributions of strength and pore-water pressures, simplistic earthquake loading, and unsaturated suction conditions. Results from Scoops3D can be readily incorporated into a geographic information system (GIS) or other visualization software. This manual includes information on the theoretical basis for the slope-stability analysis, requirements for constructing and searching a 3D domain, a detailed operational guide (including step-by-step instructions for using the graphical user interface [GUI] software, Scoops3D-i) and input/output file specifications, practical considerations for conducting an analysis, results of verification tests, and multiple examples illustrating the capabilities of Scoops3D. Easy-to-use software installation packages are available for the Windows or Macintosh operating systems; these packages
3. Scoops3D: software to analyze 3D slope stability throughout a digital landscape
Science.gov (United States)
Reid, Mark E.; Christian, Sarah B.; Brien, Dianne L.; Henderson, Scott T.
2015-01-01
The computer program, Scoops3D, evaluates slope stability throughout a digital landscape represented by a digital elevation model (DEM). The program uses a three-dimensional (3D) method of columns approach to assess the stability of many (typically millions) potential landslides within a user-defined size range. For each potential landslide (or failure), Scoops3D assesses the stability of a rotational, spherical slip surface encompassing many DEM cells using a 3D version of either Bishop’s simplified method or the Ordinary (Fellenius) method of limit-equilibrium analysis. Scoops3D has several options for the user to systematically and efficiently search throughout an entire DEM, thereby incorporating the effects of complex surface topography. In a thorough search, each DEM cell is included in multiple potential failures, and Scoops3D records the lowest stability (factor of safety) for each DEM cell, as well as the size (volume or area) associated with each of these potential landslides. It also determines the least-stable potential failure for the entire DEM. The user has a variety of options for building a 3D domain, including layers or full 3D distributions of strength and pore-water pressures, simplistic earthquake loading, and unsaturated suction conditions. Results from Scoops3D can be readily incorporated into a geographic information system (GIS) or other visualization software. This manual includes information on the theoretical basis for the slope-stability analysis, requirements for constructing and searching a 3D domain, a detailed operational guide (including step-by-step instructions for using the graphical user interface [GUI] software, Scoops3D-i) and input/output file specifications, practical considerations for conducting an analysis, results of verification tests, and multiple examples illustrating the capabilities of Scoops3D. Easy-to-use software installation packages are available for the Windows or Macintosh operating systems; these packages
4. Effect of viewing distance on 3D fatigue caused by viewing mobile 3D content
Science.gov (United States)
Mun, Sungchul; Lee, Dong-Su; Park, Min-Chul; Yano, Sumio
2013-05-01
With an advent of autostereoscopic display technique and increased needs for smart phones, there has been a significant growth in mobile TV markets. The rapid growth in technical, economical, and social aspects has encouraged 3D TV manufacturers to apply 3D rendering technology to mobile devices so that people have more opportunities to come into contact with many 3D content anytime and anywhere. Even if the mobile 3D technology leads to the current market growth, there is an important thing to consider for consistent development and growth in the display market. To put it briefly, human factors linked to mobile 3D viewing should be taken into consideration before developing mobile 3D technology. Many studies have investigated whether mobile 3D viewing causes undesirable biomedical effects such as motion sickness and visual fatigue, but few have examined main factors adversely affecting human health. Viewing distance is considered one of the main factors to establish optimized viewing environments from a viewer's point of view. Thus, in an effort to determine human-friendly viewing environments, this study aims to investigate the effect of viewing distance on human visual system when exposing to mobile 3D environments. Recording and analyzing brainwaves before and after watching mobile 3D content, we explore how viewing distance affects viewing experience from physiological and psychological perspectives. Results obtained in this study are expected to provide viewing guidelines for viewers, help ensure viewers against undesirable 3D effects, and lead to make gradual progress towards a human-friendly mobile 3D viewing.
5. PubChem3D: Similar conformers
Directory of Open Access Journals (Sweden)
Bolton Evan E
2011-05-01
Full Text Available Abstract Background PubChem is a free and open public resource for the biological activities of small molecules. With many tens of millions of both chemical structures and biological test results, PubChem is a sizeable system with an uneven degree of available information. Some chemical structures in PubChem include a great deal of biological annotation, while others have little to none. To help users, PubChem pre-computes "neighboring" relationships to relate similar chemical structures, which may have similar biological function. In this work, we introduce a "Similar Conformers" neighboring relationship to identify compounds with similar 3-D shape and similar 3-D orientation of functional groups typically used to define pharmacophore features. Results The first two diverse 3-D conformers of 26.1 million PubChem Compound records were compared to each other, using a shape Tanimoto (ST of 0.8 or greater and a color Tanimoto (CT of 0.5 or greater, yielding 8.16 billion conformer neighbor pairs and 6.62 billion compound neighbor pairs, with an average of 253 "Similar Conformers" compound neighbors per compound. Comparing the 3-D neighboring relationship to the corresponding 2-D neighboring relationship ("Similar Compounds" for molecules such as caffeine, aspirin, and morphine, one finds unique sets of related chemical structures, providing additional significant biological annotation. The PubChem 3-D neighboring relationship is also shown to be able to group a set of non-steroidal anti-inflammatory drugs (NSAIDs, despite limited PubChem 2-D similarity. In a study of 4,218 chemical structures of biomedical interest, consisting of many known drugs, using more diverse conformers per compound results in more 3-D compound neighbors per compound; however, the overlap of the compound neighbor lists per conformer also increasingly resemble each other, being 38% identical at three conformers and 68% at ten conformers. Perhaps surprising is that the average
6. FIJI Macro 3D ART VeSElecT: 3D Automated Reconstruction Tool for Vesicle Structures of Electron Tomograms.
Science.gov (United States)
Kaltdorf, Kristin Verena; Schulze, Katja; Helmprobst, Frederik; Kollmannsberger, Philip; Dandekar, Thomas; Stigloher, Christian
2017-01-01
Automatic image reconstruction is critical to cope with steadily increasing data from advanced microscopy. We describe here the Fiji macro 3D ART VeSElecT which we developed to study synaptic vesicles in electron tomograms. We apply this tool to quantify vesicle properties (i) in embryonic Danio rerio 4 and 8 days past fertilization (dpf) and (ii) to compare Caenorhabditis elegans N2 neuromuscular junctions (NMJ) wild-type and its septin mutant (unc-59(e261)). We demonstrate development-specific and mutant-specific changes in synaptic vesicle pools in both models. We confirm the functionality of our macro by applying our 3D ART VeSElecT on zebrafish NMJ showing smaller vesicles in 8 dpf embryos then 4 dpf, which was validated by manual reconstruction of the vesicle pool. Furthermore, we analyze the impact of C. elegans septin mutant unc-59(e261) on vesicle pool formation and vesicle size. Automated vesicle registration and characterization was implemented in Fiji as two macros (registration and measurement). This flexible arrangement allows in particular reducing false positives by an optional manual revision step. Preprocessing and contrast enhancement work on image-stacks of 1nm/pixel in x and y direction. Semi-automated cell selection was integrated. 3D ART VeSElecT removes interfering components, detects vesicles by 3D segmentation and calculates vesicle volume and diameter (spherical approximation, inner/outer diameter). Results are collected in color using the RoiManager plugin including the possibility of manual removal of non-matching confounder vesicles. Detailed evaluation considered performance (detected vesicles) and specificity (true vesicles) as well as precision and recall. We furthermore show gain in segmentation and morphological filtering compared to learning based methods and a large time gain compared to manual segmentation. 3D ART VeSElecT shows small error rates and its speed gain can be up to 68 times faster in comparison to manual annotation
7. 3D Printed Programmable Release Capsules.
Science.gov (United States)
Gupta, Maneesh K; Meng, Fanben; Johnson, Blake N; Kong, Yong Lin; Tian, Limei; Yeh, Yao-Wen; Masters, Nina; Singamaneni, Srikanth; McAlpine, Michael C
2015-08-12
8. Cardiothoracic Applications of 3D Printing
Science.gov (United States)
Giannopoulos, Andreas A.; Steigner, Michael L.; George, Elizabeth; Barile, Maria; Hunsaker, Andetta R.; Rybicki, Frank J.; Mitsouras, Dimitris
2016-01-01
Summary Medical 3D printing is emerging as a clinically relevant imaging tool in directing preoperative and intraoperative planning in many surgical specialties and will therefore likely lead to interdisciplinary collaboration between engineers, radiologists, and surgeons. Data from standard imaging modalities such as CT, MRI, echocardiography and rotational angiography can be used to fabricate life-sized models of human anatomy and pathology, as well as patient-specific implants and surgical guides. Cardiovascular 3D printed models can improve diagnosis and allow for advanced pre-operative planning. The majority of applications reported involve congenital heart diseases, valvular and great vessels pathologies. Printed models are suitable for planning both surgical and minimally invasive procedures. Added value has been reported toward improving outcomes, minimizing peri-operative risk, and developing new procedures such as transcatheter mitral valve replacements. Similarly, thoracic surgeons are using 3D printing to assess invasion of vital structures by tumors and to assist in diagnosis and treatment of upper and lower airway diseases. Anatomic models enable surgeons to assimilate information more quickly than image review, choose the optimal surgical approach, and achieve surgery in a shorter time. Patient-specific 3D-printed implants are beginning to appear and may have significant impact on cosmetic and life-saving procedures in the future. In summary, cardiothoracic 3D printing is rapidly evolving and may be a potential game-changer for surgeons. The imager who is equipped with the tools to apply this new imaging science to cardiothoracic care is thus ideally positioned to innovate in this new emerging imaging modality. PMID:27149367
9. Tracking earthquake source evolution in 3-D
Science.gov (United States)
Kennett, B. L. N.; Gorbatov, A.; Spiliopoulos, S.
2014-08-01
Starting from the hypocentre, the point of initiation of seismic energy, we seek to estimate the subsequent trajectory of the points of emission of high-frequency energy in 3-D, which we term the evocentres'. We track these evocentres as a function of time by energy stacking for putative points on a 3-D grid around the hypocentre that is expanded as time progresses, selecting the location of maximum energy release as a function of time. The spatial resolution in the neighbourhood of a target point can be simply estimated by spatial mapping using the properties of isochrons from the stations. The mapping of a seismogram segment to space is by inverse slowness, and thus more distant stations have a broader spatial contribution. As in hypocentral estimation, the inclusion of a wide azimuthal distribution of stations significantly enhances 3-D capability. We illustrate this approach to tracking source evolution in 3-D by considering two major earthquakes, the 2007 Mw 8.1 Solomons islands event that ruptured across a plate boundary and the 2013 Mw 8.3 event 610 km beneath the Sea of Okhotsk. In each case we are able to provide estimates of the evolution of high-frequency energy that tally well with alternative schemes, but also to provide information on the 3-D characteristics that is not available from backprojection from distant networks. We are able to demonstrate that the major characteristics of event rupture can be captured using just a few azimuthally distributed stations, which opens the opportunity for the approach to be used in a rapid mode immediately after a major event to provide guidance for, for example tsunami warning for megathrust events.
10. Laser printing of 3D metallic interconnects
Science.gov (United States)
Beniam, Iyoel; Mathews, Scott A.; Charipar, Nicholas A.; Auyeung, Raymond C. Y.; Piqué, Alberto
2016-04-01
The use of laser-induced forward transfer (LIFT) techniques for the printing of functional materials has been demonstrated for numerous applications. The printing gives rise to patterns, which can be used to fabricate planar interconnects. More recently, various groups have demonstrated electrical interconnects from laser-printed 3D structures. The laser printing of these interconnects takes place through aggregation of voxels of either molten metal or of pastes containing dispersed metallic particles. However, the generated 3D structures do not posses the same metallic conductivity as a bulk metal interconnect of the same cross-section and length as those formed by wire bonding or tab welding. An alternative is to laser transfer entire 3D structures using a technique known as lase-and-place. Lase-and-place is a LIFT process whereby whole components and parts can be transferred from a donor substrate onto a desired location with one single laser pulse. This paper will describe the use of LIFT to laser print freestanding, solid metal foils or beams precisely over the contact pads of discrete devices to interconnect them into fully functional circuits. Furthermore, this paper will also show how the same laser can be used to bend or fold the bulk metal foils prior to transfer, thus forming compliant 3D structures able to provide strain relief for the circuits under flexing or during motion from thermal mismatch. These interconnect "ridges" can span wide gaps (on the order of a millimeter) and accommodate height differences of tens of microns between adjacent devices. Examples of these laser printed 3D metallic bridges and their role in the development of next generation electronics by additive manufacturing will be presented.
11. Development of three-dimensional memory (3D-M)
Science.gov (United States)
Yu, Hong-Yu; Shen, Chen; Jiang, Lingli; Dong, Bin; Zhang, Guobiao
2016-10-01
Since the invention of 3-D ROM in 1996, three-dimensional memory (3D-M) has been under development for nearly two decades. In this presentation, we'll review the 3D-M history and compare different 3D-Ms (including 3D-OTP from Matrix Semiconductor, 3D-NAND from Samsung and 3D-XPoint from Intel/Micron).
12. Development of a 3D pixel module for an ultralarge screen 3D display
Science.gov (United States)
Hashiba, Toshihiko; Takaki, Yasuhiro
2004-10-01
A large screen 2D display used at stadiums and theaters consists of a number of pixel modules. The pixel module usually consists of 8x8 or 16x16 LED pixels. In this study we develop a 3D pixel module in order to construct a large screen 3D display which is glass-free and has the motion parallax. This configuration for a large screen 3D display dramatically reduces the complexity of wiring 3D pixels. The 3D pixel module consists of several LCD panels, several cylindrical lenses, and one small PC. The LCD panels are slanted in order to differentiate the distances from same color pixels to the axis of the cylindrical lens so that the rays from the same color pixels are refracted into the different horizontal directions by the cylindrical lens. We constructed a prototype 3D pixel module, which consists of 8x4 3D pixels. The prototype module is designed to display 300 different patterns into different horizontal directions with the horizontal display angle pitch of 0.099 degree. The LCD panels are controlled by a small PC and the 3D image data is transmitted through the Gigabit Ethernet.
13. Three-dimensional (3D) printing of mouse primary hepatocytes to generate 3D hepatic structure
Science.gov (United States)
Kim, Yohan; Kang, Kyojin; Jeong, Jaemin; Paik, Seung Sam; Kim, Ji Sook; Park, Su A; Kim, Wan Doo; Park, Jisun
2017-01-01
Purpose The major problem in producing artificial livers is that primary hepatocytes cannot be cultured for many days. Recently, 3-dimensional (3D) printing technology draws attention and this technology regarded as a useful tool for current cell biology. By using the 3D bio-printing, these problems can be resolved. Methods To generate 3D bio-printed structures (25 mm × 25 mm), cells-alginate constructs were fabricated by 3D bio-printing system. Mouse primary hepatocytes were isolated from the livers of 6–8 weeks old mice by a 2-step collagenase method. Samples of 4 × 107 hepatocytes with 80%–90% viability were printed with 3% alginate solution, and cultured with well-defined culture medium for primary hepatocytes. To confirm functional ability of hepatocytes cultured on 3D alginate scaffold, we conducted quantitative real-time polymerase chain reaction and immunofluorescence with hepatic marker genes. Results Isolated primary hepatocytes were printed with alginate. The 3D printed hepatocytes remained alive for 14 days. Gene expression levels of Albumin, HNF-4α and Foxa3 were gradually increased in the 3D structures. Immunofluorescence analysis showed that the primary hepatocytes produced hepatic-specific proteins over the same period of time. Conclusion Our research indicates that 3D bio-printing technique can be used for long-term culture of primary hepatocytes. It can therefore be used for drug screening and as a potential method of producing artificial livers. PMID:28203553
14. FI3D : Direct-Touch Interaction for the Exploration of 3D Scientific Visualization Spaces
NARCIS (Netherlands)
Yu, Lingyun; Svetachov, Pjotr; Isenberg, Petra; Everts, Maarten H.; Isenberg, Tobias
2010-01-01
We present the design and evaluation of FI3D, a direct-touch data exploration technique for 3D visualization spaces. The exploration of three-dimensional data is core to many tasks and domains involving scientific visualizations. Thus, effective data navigation techniques are essential to enable com
15. FIT3D toolbox: multiple view geometry and 3D reconstruction for Matlab
NARCIS (Netherlands)
Esteban, I.; Dijk, J.; Groen, F.
2010-01-01
FIT3D is a Toolbox built for Matlab that aims at unifying and distributing a set of tools that will allow the researcher to obtain a complete 3D model from a set of calibrated images. In this paper we motivate and present the structure of the toolbox in a tutorial and example based approach. Given i
16. FIT3D Toolbox : multiple view geometry and 3D reconstruction for MATLAB
NARCIS (Netherlands)
Esteban, I.; Dijk, J.; Groen, F.
2010-01-01
FIT3D is a Toolbox built for Matlab that aims at unifying and distributing a set of tools that will allow the researcher to obtain a complete 3D model from a set of calibrated images. In this paper we motivate and present the structure of the toolbox in a tutorial and example based approach. Given i
17. Three-dimensional (3D) printing of mouse primary hepatocytes to generate 3D hepatic structure.
Science.gov (United States)
Kim, Yohan; Kang, Kyojin; Jeong, Jaemin; Paik, Seung Sam; Kim, Ji Sook; Park, Su A; Kim, Wan Doo; Park, Jisun; Choi, Dongho
2017-02-01
The major problem in producing artificial livers is that primary hepatocytes cannot be cultured for many days. Recently, 3-dimensional (3D) printing technology draws attention and this technology regarded as a useful tool for current cell biology. By using the 3D bio-printing, these problems can be resolved. To generate 3D bio-printed structures (25 mm × 25 mm), cells-alginate constructs were fabricated by 3D bio-printing system. Mouse primary hepatocytes were isolated from the livers of 6-8 weeks old mice by a 2-step collagenase method. Samples of 4 × 10(7) hepatocytes with 80%-90% viability were printed with 3% alginate solution, and cultured with well-defined culture medium for primary hepatocytes. To confirm functional ability of hepatocytes cultured on 3D alginate scaffold, we conducted quantitative real-time polymerase chain reaction and immunofluorescence with hepatic marker genes. Isolated primary hepatocytes were printed with alginate. The 3D printed hepatocytes remained alive for 14 days. Gene expression levels of Albumin, HNF-4α and Foxa3 were gradually increased in the 3D structures. Immunofluorescence analysis showed that the primary hepatocytes produced hepatic-specific proteins over the same period of time. Our research indicates that 3D bio-printing technique can be used for long-term culture of primary hepatocytes. It can therefore be used for drug screening and as a potential method of producing artificial livers.
18. R3D-2-MSA: the RNA 3D structure-to-multiple sequence alignment server.
Science.gov (United States)
Cannone, Jamie J; Sweeney, Blake A; Petrov, Anton I; Gutell, Robin R; Zirbel, Craig L; Leontis, Neocles
2015-07-01
The RNA 3D Structure-to-Multiple Sequence Alignment Server (R3D-2-MSA) is a new web service that seamlessly links RNA three-dimensional (3D) structures to high-quality RNA multiple sequence alignments (MSAs) from diverse biological sources. In this first release, R3D-2-MSA provides manual and programmatic access to curated, representative ribosomal RNA sequence alignments from bacterial, archaeal, eukaryal and organellar ribosomes, using nucleotide numbers from representative atomic-resolution 3D structures. A web-based front end is available for manual entry and an Application Program Interface for programmatic access. Users can specify up to five ranges of nucleotides and 50 nucleotide positions per range. The R3D-2-MSA server maps these ranges to the appropriate columns of the corresponding MSA and returns the contents of the columns, either for display in a web browser or in JSON format for subsequent programmatic use. The browser output page provides a 3D interactive display of the query, a full list of sequence variants with taxonomic information and a statistical summary of distinct sequence variants found. The output can be filtered and sorted in the browser. Previous user queries can be viewed at any time by resubmitting the output URL, which encodes the search and re-generates the results. The service is freely available with no login requirement at http://rna.bgsu.edu/r3d-2-msa.
19. A 3D computer-aided design system applied to diagnosis and treatment planning in orthodontics and orthognathic surgery.
Science.gov (United States)
Motohashi, N; Kuroda, T
1999-06-01
The purpose of this article is to describe a newly developed 3D computer-aided design (CAD) system for the diagnostic set-up of casts in orthodontic diagnosis and treatment planning, and its preliminary clinical applications. The system comprises a measuring unit which obtains 3D information from the dental model using laser scanning, and a personal computer to generate the 3D graphics. When measuring the 3D shape of the model, to minimize blind sectors, the model is scanned from two different directions with the slit-ray laser beam by rotating the mounting angle of the model on the measuring device. For computed simulation of tooth movement, the representative planes, defined by the anatomical reference points, are formed for each individual tooth and are arranged along a guideline descriptive of the individual arch form. Subsequently, the 3D shape is imparted to each of the teeth arranged on the representative plane to form an arrangement of the 3D profile. When necessary, orthognathic surgery can be simulated by moving the mandibular dental arch three-dimensionally to establish the optimum occlusal relationship. Compared with hand-made set-up models, the computed diagnostic cast has advantages such as high-speed processing and quantitative evaluation on the amount of 3D movement of the individual tooth relative to the craniofacial plane. Trial clinical applications demonstrated that the use of this system facilitated the otherwise complicated and time-consuming mock surgery for treatment planning in orthognathic surgery.
20. Superconformal index and 3d-3d correspondence for mapping cylinder/torus
Energy Technology Data Exchange (ETDEWEB)
Gang, Dongmin; Koh, Eunkyung [School of Physics, Korea Institute for Advanced Study,85 Hoegiro, Seoul 130-722 (Korea, Republic of); Lee, Sangmin [Center for Theoretical Physics, Seoul National University,1 Gwanak-ro, Seoul 151-747 (Korea, Republic of); Department of Physics and Astronomy, Seoul National University,1 Gwanak-ro, Seoul 151-747 (Korea, Republic of); College of Liberal Studies, Seoul National University,1 Gwanak-ro, Seoul 151-742 (Korea, Republic of); Park, Jaemo [Department of Physics, POSTECH,77 Cheongam-Ro, Pohang 790-784 (Korea, Republic of); Postech Center for Theoretical Physics (PCTP), Postech,77 Cheongam-Ro, Pohang 790-784 (Korea, Republic of)
2014-01-15
We probe the 3d-3d correspondence for mapping cylinder/torus using the superconformal index. We focus on the case when the fiber is a once-punctured torus (Σ{sub 1,1}). The corresponding 3d field theories can be realized using duality domain wall theories in 4d N=2{sup ∗} theory. We show that the superconformal indices of the 3d theories are the SL(2,ℂ) Chern-Simons partition function on the mapping cylinder/torus. For the mapping torus, we also consider another realization of the corresponding 3d theory associated with ideal triangulation. The equality between the indices from the two descriptions for the mapping torus theory is reduced to a simple basis change of the Hilbert space for the SL(2,ℂ) Chern-Simons theory on ℝ×Σ{sub 1,1}.
1. 3D Turtle Graphics” by using a 3D Printer
Directory of Open Access Journals (Sweden)
2015-04-01
Full Text Available When creating shapes by using a 3D printer, usually, a static (declarative model designed by using a 3D CAD system is translated to a CAM program and it is sent to the printer. However, widely-used FDM-type 3D printers input a dynamical (procedural program that describes control of motions of the print head and extrusion of the filament. If the program is expressed by using a programming language or a library in a straight manner, solids can be created by a method similar to turtle graphics. An open-source library that enables “turtle 3D printing” method was described by Python and tested. Although this method currently has a problem that it cannot print in the air; however, if this problem is solved by an appropriate method, shapes drawn by 3D turtle graphics freely can be embodied by this method.
2. The dimension added by 3D scanning and 3D printing of meteorites
Science.gov (United States)
de Vet, S. J.
2016-01-01
An overview for the 3D photodocumentation of meteorites is presented, focussing on two 3D scanning methods in relation to 3D printing. The 3D photodocumention of meteorites provides new ways for the digital preservation of culturally, historically or scientifically unique meteorites. It has the potential for becoming a new documentation standard of meteorites that can exist complementary to traditional photographic documentation. Notable applications include (i.) use of physical properties in dark flight-, strewn field-, or aerodynamic modelling; (ii.) collection research of meteorites curated by different museum collections, and (iii.) public dissemination of meteorite models as a resource for educational users. The possible applications provided by the additional dimension of 3D illustrate the benefits for the meteoritics community.
3. 3D Model Optimization of Four-Facet Drill for 3D Drilling Simulation
Directory of Open Access Journals (Sweden)
Buranský Ivan
2016-09-01
Full Text Available The article is focused on optimization of four-facet drill for 3D drilling numerical modelling. For optimization, the process of reverse engineering by PowerShape software was used. The design of four-facet drill was created in NumrotoPlus software. The modified 3D model of the drill was used in the numerical analysis of cutting forces. Verification of the accuracy of 3D models for reverse engineering was implemented using the colour deviation maps. The CAD model was in the STEP format. For simulation software, 3D model in the STEP format is ideal. STEP is a solid model. Simulation software automatically splits the 3D model into finite elements. The STEP model was therefore more suitable than the STL model.
4. Quasi 3D dosimetry (EPID, conventional 2D/3D detector matrices)
Science.gov (United States)
Bäck, A.
2015-01-01
Patient specific pretreatment measurement for IMRT and VMAT QA should preferably give information with a high resolution in 3D. The ability to distinguish complex treatment plans, i.e. treatment plans with a difference between measured and calculated dose distributions that exceeds a specified tolerance, puts high demands on the dosimetry system used for the pretreatment measurements and the results of the measurement evaluation needs a clinical interpretation. There are a number of commercial dosimetry systems designed for pretreatment IMRT QA measurements. 2D arrays such as MapCHECK® (Sun Nuclear), MatriXXEvolution (IBA Dosimetry) and OCTAVIOUS® 1500 (PTW), 3D phantoms such as OCTAVIUS® 4D (PTW), ArcCHECK® (Sun Nuclear) and Delta4 (ScandiDos) and software for EPID dosimetry and 3D reconstruction of the dose in the patient geometry such as EPIDoseTM (Sun Nuclear) and Dosimetry CheckTM (Math Resolutions) are available. None of those dosimetry systems can measure the 3D dose distribution with a high resolution (full 3D dose distribution). Those systems can be called quasi 3D dosimetry systems. To be able to estimate the delivered dose in full 3D the user is dependent on a calculation algorithm in the software of the dosimetry system. All the vendors of the dosimetry systems mentioned above provide calculation algorithms to reconstruct a full 3D dose in the patient geometry. This enables analyzes of the difference between measured and calculated dose distributions in DVHs of the structures of clinical interest which facilitates the clinical interpretation and is a promising tool to be used for pretreatment IMRT QA measurements. However, independent validation studies on the accuracy of those algorithms are scarce. Pretreatment IMRT QA using the quasi 3D dosimetry systems mentioned above rely on both measurement uncertainty and accuracy of calculation algorithms. In this article, these quasi 3D dosimetry systems and their use in patient specific pretreatment IMRT
5. INCORPORATING DYNAMIC 3D SIMULATION INTO PRA
Energy Technology Data Exchange (ETDEWEB)
Steven R Prescott; Curtis Smith
2011-07-01
Through continued advancement in computational resources, development that was previously done by trial and error production is now performed through computer simulation. These virtual physical representations have the potential to provide accurate and valid modeling results and are being used in many different technical fields. Risk assessment now has the opportunity to use 3D simulation to improve analysis results and insights, especially for external event analysis. By using simulations, the modeler only has to determine the likelihood of an event without having to also predict the results of that event. The 3D simulation automatically determines not only the outcome of the event, but when those failures occur. How can we effectively incorporate 3D simulation into traditional PRA? Most PRA plant modeling is made up of components with different failure modes, probabilities, and rates. Typically, these components are grouped into various systems and then are modeled together (in different combinations) as a “system” with logic structures to form fault trees. Applicable fault trees are combined through scenarios, typically represented by event tree models. Though this method gives us failure results for a given model, it has limitations when it comes to time-based dependencies or dependencies that are coupled to physical processes which may themselves be space- or time-dependent. Since, failures from a 3D simulation are naturally time related, they should be used in that manner. In our simulation approach, traditional static models are converted into an equivalent state diagram representation with start states, probabilistic driven movements between states and terminal states. As the state model is run repeatedly, it converges to the same results as the PRA model in cases where time-related factors are not important. In cases where timing considerations are important (e.g., when events are dependent upon each other), then the simulation approach will typically
6. 3D visualization of polymer nanostructure
Energy Technology Data Exchange (ETDEWEB)
Werner, James H [Los Alamos National Laboratory
2009-01-01
Soft materials and structured polymers are extremely useful nanotechnology building blocks. Block copolymers, in particular, have served as 2D masks for nanolithography and 3D scaffolds for photonic crystals, nanoparticle fabrication, and solar cells. F or many of these applications, the precise 3 dimensional structure and the number and type of defects in the polymer is important for ultimate function. However, directly visualizing the 3D structure of a soft material from the nanometer to millimeter length scales is a significant technical challenge. Here, we propose to develop the instrumentation needed for direct 3D structure determination at near nanometer resolution throughout a nearly millimeter-cubed volume of a soft, potentially heterogeneous, material. This new capability will be a valuable research tool for LANL missions in chemistry, materials science, and nanoscience. Our approach to soft materials visualization builds upon exciting developments in super-resolution optical microscopy that have occurred over the past two years. To date, these new, truly revolutionary, imaging methods have been developed and almost exclusively used for biological applications. However, in addition to biological cells, these super-resolution imaging techniques hold extreme promise for direct visualization of many important nanostructured polymers and other heterogeneous chemical systems. Los Alamos has a unique opportunity to lead the development of these super-resolution imaging methods for problems of chemical rather than biological significance. While these optical methods are limited to systems transparent to visible wavelengths, we stress that many important functional chemicals such as polymers, glasses, sol-gels, aerogels, or colloidal assemblies meet this requirement, with specific examples including materials designed for optical communication, manipulation, or light-harvesting Our Research Goals are: (1) Develop the instrumentation necessary for imaging materials
7. CASTLE3D - A Computer Aided System for Labelling Archaeological Excavations in 3D
Science.gov (United States)
Houshiar, H.; Borrmann, D.; Elseberg, J.; Nüchter, A.; Näth, F.; Winkler, S.
2015-08-01
Documentation of archaeological excavation sites with conventional methods and tools such as hand drawings, measuring tape and archaeological notes is time consuming. This process is prone to human errors and the quality of the documentation depends on the qualification of the archaeologist on site. Use of modern technology and methods in 3D surveying and 3D robotics facilitate and improve this process. Computer-aided systems and databases improve the documentation quality and increase the speed of data acquisition. 3D laser scanning is the state of the art in modelling archaeological excavation sites, historical sites and even entire cities or landscapes. Modern laser scanners are capable of data acquisition of up to 1 million points per second. This provides a very detailed 3D point cloud of the environment. 3D point clouds and 3D models of an excavation site provide a better representation of the environment for the archaeologist and for documentation. The point cloud can be used both for further studies on the excavation and for the presentation of results. This paper introduces a Computer aided system for labelling archaeological excavations in 3D (CASTLE3D). Consisting of a set of tools for recording and georeferencing the 3D data from an excavation site, CASTLE3D is a novel documentation approach in industrial archaeology. It provides a 2D and 3D visualisation of the data and an easy-to-use interface that enables the archaeologist to select regions of interest and to interact with the data in both representations. The 2D visualisation and a 3D orthogonal view of the data provide cuts of the environment that resemble the traditional hand drawings. The 3D perspective view gives a realistic view of the environment. CASTLE3D is designed as an easy-to-use on-site semantic mapping tool for archaeologists. Each project contains a predefined set of semantic information that can be used to label findings in the data. Multiple regions of interest can be joined under
8. Impact of Particle Size of Ceramic Granule Blends on Mechanical Strength and Porosity of 3D Printed Scaffolds
Directory of Open Access Journals (Sweden)
Sebastian Spath
2015-07-01
Full Text Available 3D printing is a promising method for the fabrication of scaffolds in the field of bone tissue engineering. To date, the mechanical strength of 3D printed ceramic scaffolds is not sufficient for a variety of applications in the reconstructive surgery. Mechanical strength is directly in relation with the porosity of the 3D printed scaffolds. The porosity is directly influenced by particle size and particle-size distribution of the raw material. To investigate this impact, a hydroxyapatite granule blend with a wide particle size distribution was fractioned by sieving. The specific fractions and bimodal mixtures of the sieved granule blend were used to 3D print specimens. It has been shown that an optimized arrangement of fractions with large and small particles can provide 3D printed specimens with good mechanical strength due to a higher packing density. An increase of mechanical strength can possibly expand the application area of 3D printed hydroxyapatite scaffolds.
9. 2D and 3D multimodality cardiac imagery: application for the coronarography/SPECT/PET-CT; Imagerie cardiaque multimodalites 2D et 3D: application a la coronarographie/tomoscintigraphie/TEP-CT
Energy Technology Data Exchange (ETDEWEB)
Lopez Hernandez, J.M
2006-06-15
Coronarography and tomo-scintigraphy (SPECT, Single Photon Emission Tomography) are two imaging techniques used broadly for the diagnosis of cardiovascular diseases. The first modality consists of X-ray image sequences visualizing each, in a same plane, the coronary arteries located on the front and the back side of the heart. The X-ray images give anatomical information relating to the arterial tree and highlight eventual artery narrowing (stenoses). The SPECT modality (nuclear imaging) provide a 3-dimensional (3D) representation of the myocardial volume perfusion. This functional information authorizes the visualization of myocardial regions suffering from irrigation defaults. The aim of the presented work is to superimpose (in the 3D space) the functional and anatomical information in order to establish the visual link between arterial lesions and their consequence in terms of irrigation defaults. In the 3D representation chosen to facilitate the diagnosis, the structure of a schematic arterial tree and the stenoses are placed onto the perfusion volume. The initial data consist of a list of points representative for the arterial tree (start and end points of arterial segments, bifurcations, stenoses, etc) and marked by coronary-graphs on the X-ray images of the different incidences. The perfusion volume is then projected under the incidences of the coronary-graphic images. A registration algorithm superimposing the X-ray images and the corresponding SPECT projections provides the parameters of the geometrical transformations bringing the points marked in the X rays images in equivalent positions in the 2-dimensional SPECT images. A 3D reconstruction algorithm is then used to place the arterial points and the stenoses on the perfusion volume and build a schematic tree acting as landmark for the clinician. A 28 patient database was used to realize 40 3D superimposition of anatomical-functional data. These reconstructions have shown that the 3D representation is
10. Micromachined Ultrasonic Transducers for 3-D Imaging
DEFF Research Database (Denmark)
Christiansen, Thomas Lehrmann
such transducer arrays, capacitive micromachined ultrasonic transducer (CMUT) technology is chosen for this project. Properties such as high bandwidth and high design flexibility makes this an attractive transducer technology, which is under continuous development in the research community. A theoretical...... of state-of-the-art 3-D ultrasound systems. The focus is on row-column addressed transducer arrays. This previously sparsely investigated addressing scheme offers a highly reduced number of transducer elements, resulting in reduced transducer manufacturing costs and data processing. To produce......Real-time ultrasound imaging is a widely used technique in medical diagnostics. Recently, ultrasound systems offering real-time imaging in 3-D has emerged. However, the high complexity of the transducer probes and the considerable increase in data to be processed compared to conventional 2-D...
11. Sensing and compressing 3-D models
Energy Technology Data Exchange (ETDEWEB)
Krumm, J. [Sandia National Labs., Albuquerque, NM (United States). Intelligent System Sensors and Controls Dept.
1998-02-01
The goal of this research project was to create a passive and robust computer vision system for producing 3-D computer models of arbitrary scenes. Although the authors were unsuccessful in achieving the overall goal, several components of this research have shown significant potential. Of particular interest is the application of parametric eigenspace methods for planar pose measurement of partially occluded objects in gray-level images. The techniques presented provide a simple, accurate, and robust solution to the planar pose measurement problem. In addition, the representational efficiency of eigenspace methods used with gray-level features were successfully extended to binary features, which are less sensitive to illumination changes. The results of this research are presented in two papers that were written during the course of this project. The papers are included in sections 2 and 3. The first section of this report summarizes the 3-D modeling efforts.
12. Laser scanner 3D terrestri e mobile
Directory of Open Access Journals (Sweden)
Mario Ciamba
2013-08-01
Full Text Available Recentemente si è svolto a Roma un evento dimostrativo per informare, professionisti e ricercatori del settore inerente il rilievo strumentale, sulle recenti innovazioni che riguardano i laser scanner 3d. Il mercato della strumentazione dedicata al rilevamento architettonico e dell'ambiente, offre molte possibilità di scelta. Oggi i principali marchi producono strumenti sempre più efficienti ed ideati per ambiti di applicazione specifici, permettendo ai professionisti, la giusta scelta in termini di prestazioni ed economia.A demonstration event was recently held in Rome with the aim to inform professionals and researchers on recent innovations on instrumental survey related to the 3d laser scanner. The market of instrumentation for architectural survey offers many possibilitiesof choice. Today the major brands produce instruments that are more efficient and designed for specific areas of application, allowing the right choice in terms of performance and economy.
13. Illustrating the disassembly of 3D models
KAUST Repository
Guo, Jianwei
2013-10-01
We present a framework for the automatic disassembly of 3D man-made models and the illustration of the disassembly process. Given an assembled 3D model, we first analyze the individual parts using sharp edge loops and extract the contact faces between each pair of neighboring parts. The contact faces are then used to compute the possible moving directions of each part. We then present a simple algorithm for clustering the sets of the individual parts into meaningful sub-assemblies, which can be used for a hierarchical decomposition. We take the stability of sub-assemblies into account during the decomposition process by considering the upright orientation of the input models. Our framework also provides a user-friendly interface to enable the superimposition of the constraints for the decomposition. Finally, we visualize the disassembly process by generating an animated sequence. The experiments demonstrate that our framework works well for a variety of complex models. © 2013 Elsevier Ltd.
14. 3D Structure and Nuclear Targets
CERN Document Server
Dupré, R
2015-01-01
Recent experimental and theoretical ideas are laying the ground for a new era in the knowledge of the parton structure of nuclei. We report on two promising directions beyond inclusive deep inelastic scattering experiments, aimed at, among other goals, unveiling the three dimensional structure of the bound nucleon. The 3D structure in coordinate space can be accessed through deep exclusive processes, whose non-perturbative content is parametrized in terms of generalized parton distributions. In this way the distribution of partons in the transverse plane will be obtained, providing a pictorial view of the realization of the European Muon Collaboration effect. In particular, we show how, through the generalized parton distribution framework, non nucleonic degrees of freedom in nuclei can be unveiled. Analogously, the momentum space 3D structure can be accessed by studying transverse momentum dependent parton distributions in semi-inclusive deep inelastic scattering processes. The status of measurements is also...
15. Technologies for 3D Heterogeneous Integration
CERN Document Server
Wolf, Jürgen; Klumpp, Armin; Reichl, H
2008-01-01
3D-Integration is a promising technology towards higher interconnect densities and shorter wiring lengths between multiple chip stacks, thus achieving a very high performance level combined with low power consumption. This technology also offers the possibility to build up systems with high complexity just by combining devices of different technologies. For ultra thin silicon is the base of this integration technology, the fundamental processing steps will be described, as well as appropriate handling concepts. Three main concepts for 3D integration have been developed at IZM. The approach with the greatest flexibility called Inter Chip Via - Solid Liquid Interdiffusion (ICV-SLID) is introduced. This is a chip-to-wafer stacking technology which combines the advantages of the Inter Chip Via (ICV) process and the solid-liquid-interdiffusion technique (SLID) of copper and tin. The fully modular ICV-SLID concept allows the formation of multiple device stacks. A test chip was designed and the total process sequenc...
16. 3D FFTs on a Single FPGA.
Science.gov (United States)
Humphries, Benjamin; Zhang, Hansen; Sheng, Jiayi; Landaverde, Raphael; Herbordt, Martin C
2014-05-01
The 3D FFT is critical in many physical simulations and image processing applications. On FPGAs, however, the 3D FFT was thought to be inefficient relative to other methods such as convolution-based implementations of multi-grid. We find the opposite: a simple design, operating at a conservative frequency, takes 4μs for 16(3), 21μs for 32(3), and 215μs for 64(3) single precision data points. The first two of these compare favorably with the 25μs and 29μs obtained running on a current Nvidia GPU. Some broader significance is that this is a critical piece in implementing a large scale FPGA-based MD engine: even a single FPGA is capable of keeping the FFT off of the critical path for a large fraction of possible MD simulations.
17. 3D Visualization of Cooperative Trajectories
Science.gov (United States)
Schaefer, John A.
2014-01-01
Aerodynamicists and biologists have long recognized the benefits of formation flight. When birds or aircraft fly in the upwash region of the vortex generated by leaders in a formation, induced drag is reduced for the trail bird or aircraft, and efficiency improves. The major consequence of this is that fuel consumption can be greatly reduced. When two aircraft are separated by a large enough longitudinal distance, the aircraft are said to be flying in a cooperative trajectory. A simulation has been developed to model autonomous cooperative trajectories of aircraft; however it does not provide any 3D representation of the multi-body system dynamics. The topic of this research is the development of an accurate visualization of the multi-body system observable in a 3D environment. This visualization includes two aircraft (lead and trail), a landscape for a static reference, and simplified models of the vortex dynamics and trajectories at several locations between the aircraft.
18. 3D measurement using circular gratings
Science.gov (United States)
Harding, Kevin
2013-09-01
3D measurement using methods of structured light are well known in the industry. Most such systems use some variation of straight lines, either as simple lines or with some form of encoding. This geometry assumes the lines will be projected from one side and viewed from another to generate the profile information. But what about applications where a wide triangulation angle may not be practical, particularly at longer standoff distances. This paper explores the use of circular grating patterns projected from a center point to achieve 3D information. Originally suggested by John Caulfield around 1990, the method had some interesting potential, particularly if combined with alternate means of measurement from traditional triangulation including depth from focus methods. The possible advantages of a central reference point in the projected pattern may offer some different capabilities not as easily attained with a linear grating pattern. This paper will explore the pros and cons of the method and present some examples of possible applications.
19. 3D Multifunctional Ablative Thermal Protection System
Science.gov (United States)
Feldman, Jay; Venkatapathy, Ethiraj; Wilkinson, Curt; Mercer, Ken
2015-01-01
NASA is developing the Orion spacecraft to carry astronauts farther into the solar system than ever before, with human exploration of Mars as its ultimate goal. One of the technologies required to enable this advanced, Apollo-shaped capsule is a 3-dimensional quartz fiber composite for the vehicle's compression pad. During its mission, the compression pad serves first as a structural component and later as an ablative heat shield, partially consumed on Earth re-entry. This presentation will summarize the development of a new 3D quartz cyanate ester composite material, 3-Dimensional Multifunctional Ablative Thermal Protection System (3D-MAT), designed to meet the mission requirements for the Orion compression pad. Manufacturing development, aerothermal (arc-jet) testing, structural performance, and the overall status of material development for the 2018 EM-1 flight test will be discussed.
20. Neural Network Based 3D Surface Reconstruction
Directory of Open Access Journals (Sweden)
Vincy Joseph
2009-11-01
Full Text Available This paper proposes a novel neural-network-based adaptive hybrid-reflectance three-dimensional (3-D surface reconstruction model. The neural network combines the diffuse and specular components into a hybrid model. The proposed model considers the characteristics of each point and the variant albedo to prevent the reconstructed surface from being distorted. The neural network inputs are the pixel values of the two-dimensional images to be reconstructed. The normal vectors of the surface can then be obtained from the output of the neural network after supervised learning, where the illuminant direction does not have to be known in advance. Finally, the obtained normal vectors can be applied to integration method when reconstructing 3-D objects. Facial images were used for training in the proposed approach
1. 3D GEO: AN ALTERNATIVE APPROACH
Directory of Open Access Journals (Sweden)
A. Georgopoulos
2016-10-01
Full Text Available The expression GEO is mostly used to denote relation to the earth. However it should not be confined to what is related to the earth's surface, as other objects also need three dimensional representation and documentation, like cultural heritage objects. They include both tangible and intangible ones. In this paper the 3D data acquisition and 3D modelling of cultural heritage assets are briefly described and their significance is also highlighted. Moreover the organization of such information, related to monuments and artefacts, into relational data bases and its use for various purposes, other than just geometric documentation is also described and presented. In order to help the reader understand the above, several characteristic examples are presented and their methodology explained and their results evaluated.
2. 3D Geo: An Alternative Approach
Science.gov (United States)
Georgopoulos, A.
2016-10-01
The expression GEO is mostly used to denote relation to the earth. However it should not be confined to what is related to the earth's surface, as other objects also need three dimensional representation and documentation, like cultural heritage objects. They include both tangible and intangible ones. In this paper the 3D data acquisition and 3D modelling of cultural heritage assets are briefly described and their significance is also highlighted. Moreover the organization of such information, related to monuments and artefacts, into relational data bases and its use for various purposes, other than just geometric documentation is also described and presented. In order to help the reader understand the above, several characteristic examples are presented and their methodology explained and their results evaluated.
3. Essentials of 3D biofabrication and translation
CERN Document Server
Atala, Anthony
2015-01-01
Essentials of 3D Biofabrication and Translation discusses the techniques that are making bioprinting a viable alternative in regenerative medicine. The book runs the gamut of topics related to the subject, including hydrogels and polymers, nanotechnology, toxicity testing, and drug screening platforms, also introducing current applications in the cardiac, skeletal, and nervous systems, and organ construction. Leaders in clinical medicine and translational science provide a global perspective of the transformative nature of this field, including the use of cells, biomaterials, and macromolecules to create basic building blocks of tissues and organs, all of which are driving the field of biofabrication to transform regenerative medicine. Provides a new and versatile method to fabricating living tissue Discusses future applications for 3D bioprinting technologies, including use in the cardiac, skeletal, and nervous systems, and organ construction Describes current approaches and future challenges for translation...
4. High accuracy 3-D laser radar
DEFF Research Database (Denmark)
Busck, Jens; Heiselberg, Henning
2004-01-01
We have developed a mono-static staring 3-D laser radar based on gated viewing with range accuracy below 1 m at 10 m and 1 cm at 100. We use a high sensitivity, fast, intensified CCD camera, and a Nd:Yag passively Q-switched 32.4 kHz pulsed green laser at 532 nm. The CCD has 752x582 pixels. Camera...... shutter is controlled in steps of 100 ps. Camera delay is controlled in steps of 100 ps. Each laser pulse triggers the camera delay and shutter. A 3-D image is constructed from a sequence of 50-100 2-D reflectivity images, where each frame integrates about 700 laser pulses on the CCD. In 50 Hz video mode...
5. Fabricating 3D figurines with personalized faces.
Science.gov (United States)
Tena, J Rafael; Mahler, Moshe; Beeler, Thabo; Grosse, Max; Hengchin Yeh; Matthews, Iain
2013-01-01
We present a semi-automated system for fabricating figurines with faces that are personalised to the individual likeness of the customer. The efficacy of the system has been demonstrated by commercial deployments at Walt Disney World Resort and Star Wars Celebration VI in Orlando Florida. Although the system is semi automated, human intervention is limited to a few simple tasks to maintain the high throughput and consistent quality required for commercial application. In contrast to existing systems that fabricate custom heads that are assembled to pre-fabricated plastic bodies, our system seamlessly integrates 3D facial data with a predefined figurine body into a unique and continuous object that is fabricated as a single piece. The combination of state-of-the-art 3D capture, modelling, and printing that are the core of our system provide the flexibility to fabricate figurines whose complexity is only limited by the creativity of the designer.
6. Factorising the 3D Topologically Twisted Index
CERN Document Server
Cabo-Bizet, Alejandro
2016-01-01
In this work, path integral representations of the 3D topologically twisted index were studied. First, the index can be "factorised" into a couple of "blocks". The "blocks" being the partition functions of a type A semi-topological twisting of 3D N = 2 SYM placed on $\\mathbb{S}_2\\times (0, \\pi)$ and $\\mathbb{S}_2 \\times (\\pi, 2 \\pi)$ respectively. Second, as the path integral of the aforementioned theory over $\\mathbb{S}_2$ times $\\mathbb{S}_1$ with a point excluded. In this way we recover the sum over fluxes from integration over the real path and without sacrificing positive definiteness of the bosonic part of the localising action. We also reproduce the integration over the complex contour by using the localising term with positive definite bosonic part.
7. Debris Dispersion Model Using Java 3D
Science.gov (United States)
Thirumalainambi, Rajkumar; Bardina, Jorge
2004-01-01
This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java 3D graphics provides geometric and visual content with suitable mathematical model and behaviors of Shuttle launch. Because the model is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models provides mechanisms to understand the complexity of launch and range operations. The main focus in the modeling and simulation covers orbital dynamics and range safety. Range safety areas include destruct limit lines, telemetry and tracking and population risk near range. If there is an explosion of Shuttle during launch, debris dispersion is explained. The shuttle launch and range operations in this paper are discussed based on the operations from Kennedy Space Center, Florida, USA.
8. 3D Morphing Using Strain Field Interpolation
Institute of Scientific and Technical Information of China (English)
Han-Bing Yan; Shi-Min Hu; Ralph R Martin
2007-01-01
In this paper, we present a new technique based on strain fields to carry out 3D shape morphing for applicationsin computer graphics and related areas.Strain is an important geometric quantity used in mechanics to describe the deformation of objects.We apply it in a novel way to analyze and control deformation in morphing.Using position vector fields, the strain field relating source and target shapes can be obtained.By interpolating this strain field between zero and a final desired value we can obtain the position field for intermediate shapes.This method ensures that the 3D morphing process is smooth.Locally, volumes suffer minimal distortion, and no shape jittering or wobbling happens: other methods do not necessarily have these desirable properties.We also show how to control the method so that changes of shape (in particular, size changes) vary linearly with time.
9. Circuit QED with 3D cavities
Energy Technology Data Exchange (ETDEWEB)
Xie, Edwar; Baust, Alexander; Zhong, Ling; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Anderson, Gustav; Wang, Lujun; Eder, Peter; Fischer, Michael; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Wulschner, Karl Friedrich; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Menzel, Edwin [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany)
2015-07-01
In typical circuit QED systems on-chip superconducting qubits are coupled to integrated coplanar microwave resonators. Due to the planar geometry, the resonators are often a limiting factor regarding the total coherence of the system. Alternatively, similar hybrid systems can be realized using 3D microwave cavities. Here, we present design considerations for the 3D microwave cavity as well as the superconducting transmon qubit. Moreover, we show experimental data of a high purity aluminum cavity demonstrating quality factors above 1.4 .10{sup 6} at the single photon level and a temperature of 50 mK. Our experiments also demonstrate that the quality factor is less dependent on the power compared to planar resonator geometries. Furthermore, we present strategies for tuning both the cavity and the qubit individually.
10. 3D Neutrophil Tractions in Changing Microenvironments
Science.gov (United States)
Toyjanova, Jennet; Flores, Estefany; Reichner, Jonathan; Franck, Christian
2012-02-01
Neutrophils are well-known as first responders to defend the body against life threatening bacterial diseases, infections and inflammation. The mechanical properties and the local topography of the surrounding microenvironment play a significant role in the regulating neutrophil behavior including cell adhesion, migration and generation of tractions. In navigating to the site of infection, neutrophils are exposed to changing microenvironments that differ in their composition, structure and mechanical properties. Our goal is to investigate neutrophil behavior, specifically migration and cellular tractions in a well-controlled 3D in vitro system. By utilizing an interchangeable 2D-3D sandwich gel structure system with tunable mechanical properties neutrophil migration and cell tractions can be computed as a function of gel stiffness and geometric dimensionality.
11. Wireless Power Transfer in 3D Space
Directory of Open Access Journals (Sweden)
C.Bhuvaneshvari
2014-06-01
Full Text Available The main objective of this project is to develop a system of wireless power transfer in 3D space. This concept based on low frequency to high frequency conversion. High frequency power is transmit between air-core and inductor. This work presents an experiment for wireless energy transfer by using the Inductive resonant coupling (also known as resonant energy transfer phenomenon. The basic principles will be presented about this physical phenomenon, the experiment design, and the results obtained for the measurements performed on the system. The parameters measured were the efficiency of the power transfer, and the angle between emitter and receiver. We can achieve wireless power transfer up to 10watts in 3D space using high frequency through tuned circuit. The wireless power supply is motivated by simple and comfortable use of many small electric appliances with low power input.
12. Facial reconstruction using 3-D computer graphics.
Science.gov (United States)
Vanezi, P; Vanezis, M; McCombe, G; Niblett, T
2000-02-14
Facial reconstruction using 3-D computer graphics is being used in our institute as a routine procedure in forensic cases as well as for skulls of historical and archaeological interest. Skull and facial data from living subjects is acquired using an optical laser scanning system. For the production of the reconstructed image, we employ facial reconstruction software which is constructed using the TCL/Tk scripting language, the latter making use of the C3D system. The computer image may then be exported to enable the production of a solid model, employing, for example, stereolithography. The image can also be modified within an identikit system which allows the addition of facial features as appropriate.
13. High accuracy 3-D laser radar
DEFF Research Database (Denmark)
Busck, Jens; Heiselberg, Henning
2004-01-01
We have developed a mono-static staring 3-D laser radar based on gated viewing with range accuracy below 1 m at 10 m and 1 cm at 100. We use a high sensitivity, fast, intensified CCD camera, and a Nd:Yag passively Q-switched 32.4 kHz pulsed green laser at 532 nm. The CCD has 752x582 pixels. Camera...
14. 3D geodetic monitoring slope deformations
Directory of Open Access Journals (Sweden)
Weiss Gabriel
1996-06-01
Full Text Available For plenty of slope failures that can be found in Slovakia is necessary and very important their geodetic monitoring (because of their activity, reactivisations, checks. The paper gives new methodologies for these works, using 3D terrestrial survey technologies for measurements in convenient deformation networks. The design of an optimal type of deformation model for various kinds of landslides and their exact processing with an efficient testing procedure to determine the kinematics of the slope deformations are presented too.
15. Lattice Radial Quantization: 3D Ising
CERN Document Server
Brower, Richard; Neuberger, Herbert
2012-01-01
Lattice radial quantization is introduced as a nonperturbative method intended to numerically solve Euclidean conformal field theories that can be realized as fixed points of known Lagrangians. As an example, we employ a lattice shaped as a cylinder with a 2D Icosahedral cross-section to discretize dilatations in the 3D Ising model. Using this method, we obtain the preliminary estimate eta=0.034(10).
16. Watermarking 3D Objects for Verification
Science.gov (United States)
1999-01-01
signal ( audio /image/video) pro- cessing and steganography fields, and even newer to the computer graphics community. Inherently, digital watermarking of...Many view digital watermarking as a potential solution for copyright protection of valuable digital materials like CD-quality audio , publication...watermark. The object can be an image, an audio clip, a video clip, or a 3D model. Some papers discuss watermarking other forms of multime- dia data
17. Remote Collaborative 3D Printing - Process Investigation
Science.gov (United States)
2016-04-01
such products. 9.1. Additive Manufacturing Hardware Wish List • Multi-axis FDM machine capable of complex layups: An FDM system with a 4th and...transferring, receiving, manipulating, and printing a digital 3D model into an additively manufactured component. Several digital models were...into an additively manufactured component. Several digital models were exchanged, and the steps, barriers, workarounds, and results have been
18. 3D Integration for Wireless Multimedia
Science.gov (United States)
Kimmich, Georg
The convergence of mobile phone, internet, mapping, gaming and office automation tools with high quality video and still imaging capture capability is becoming a strong market trend for portable devices. High-density video encode and decode, 3D graphics for gaming, increased application-software complexity and ultra-high-bandwidth 4G modem technologies are driving the CPU performance and memory bandwidth requirements close to the PC segment. These portable multimedia devices are battery operated, which requires the deployment of new low-power-optimized silicon process technologies and ultra-low-power design techniques at system, architecture and device level. Mobile devices also need to comply with stringent silicon-area and package-volume constraints. As for all consumer devices, low production cost and fast time-to-volume production is key for success. This chapter shows how 3D architectures can bring a possible breakthrough to meet the conflicting power, performance and area constraints. Multiple 3D die-stacking partitioning strategies are described and analyzed on their potential to improve the overall system power, performance and cost for specific application scenarios. Requirements and maturity of the basic process-technology bricks including through-silicon via (TSV) and die-to-die attachment techniques are reviewed. Finally, we highlight new challenges which will arise with 3D stacking and an outlook on how they may be addressed: Higher power density will require thermal design considerations, new EDA tools will need to be developed to cope with the integration of heterogeneous technologies and to guarantee signal and power integrity across the die stack. The silicon/wafer test strategies have to be adapted to handle high-density IO arrays, ultra-thin wafers and provide built-in self-test of attached memories. New standards and business models have to be developed to allow cost-efficient assembly and testing of devices from different silicon and technology
19. 3D cartography of the Alpine Arc
Science.gov (United States)
Vouillamoz, N.; Sue, C.; Champagnac, J. D.; Calcagno, P.
2012-04-01
We present a 3D cartography of the alpine arc, a highly non-cylindrical mountain belt, built using the 3D GeoModeller of the BRGM (French geological survey). The model allows to handle the large-scale 3D structure of seventeen major crustal units of the belt (from the lower crust to the sedimentary cover nappes), and two main discontinuities (the Insubric line and the Crustal Penninic Front). It provides a unique document to better understand their structural relationships and to produce new sections. The study area comprises the western alpine arc, from the Jura to the Northwest, up to the Bergell granite intrusion and the Lepontine Dome to the East, and is limited to the South by the Ligurian basin. The model is limited vertically 10 km above sea level at the top, and the moho interface at the bottom. We discarded the structural relationships between the Alps sensus stricto and the surrounding geodynamic systems such as the Rhine graben or the connection with the Apennines. The 3D-model is based on the global integration of various data such as the DEM of the Alps, the moho isobaths, the simplified geological and tectonic maps of the belt, the crustal cross-sections ECORS-CROP and NFP-20, and complementary cross-sections specifically built to precise local complexities. The database has first been integrated in a GIS-project to prepare their implementation in the GeoModeller, by homogenizing the different spatial referencing systems. The global model is finally interpolated from all these data, using the potential field method. The final document is a new tri-dimentional cartography that would be used as input for further alpine studies.
20. INTERACTIVE 3D LANDSCAPES ON LINE
Directory of Open Access Journals (Sweden)
B. Fanini
2012-09-01
Full Text Available The paper describes challenges identified while developing browser embedded 3D landscape rendering applications, our current approach and work-flow and how recent development in browser technologies could affect. All the data, even if processed by optimization and decimation tools, result in very huge databases that require paging, streaming and Level-of-Detail techniques to be implemented to allow remote web based real time fruition. Our approach has been to select an open source scene-graph based visual simulation library with sufficient performance and flexibility and adapt it to the web by providing a browser plug-in. Within the current Montegrotto VR Project, content produced with new pipelines has been integrated. The whole Montegrotto Town has been generated procedurally by CityEngine. We used this procedural approach, based on algorithms and procedures because it is particularly functional to create extensive and credible urban reconstructions. To create the archaeological sites we used optimized mesh acquired with laser scanning and photogrammetry techniques whereas to realize the 3D reconstructions of the main historical buildings we adopted computer-graphic software like blender and 3ds Max. At the final stage, semi-automatic tools have been developed and used up to prepare and clusterise 3D models and scene graph routes for web publishing. Vegetation generators have also been used with the goal of populating the virtual scene to enhance the user perceived realism during the navigation experience. After the description of 3D modelling and optimization techniques, the paper will focus and discuss its results and expectations. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.33060890436172485, "perplexity": 4631.481441152138}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-09/segments/1518891812758.43/warc/CC-MAIN-20180219171550-20180219191550-00550.warc.gz"} |
http://cepi.in/if-dogs-oqgxfr/175045-oxidation-state-rules | This is a simple list of the rules for applying Oxidation States, with examples for students to understand the rules. The oxidation number of an atom in an element is always zero. http://apchemcyhs.wikispaces.com/ In general, hydrogen has an oxidation state of +1, while oxygen has an oxidation state of -2. According to rule 4, hydrogen atoms have an oxidation state of +1. Yes. In ions, the algebraic sum of the oxidation states of the constituent atoms must be equal to the charge on the ion. The oxidation number of hydrogen is -1 in compounds containing elements that are less , The oxidation number of oxygen in compounds is usually -2. For example, in … The oxidation state of an atom is calculated under seven rules. In some cases, the average oxidation state of an element is a fraction, such as 8/3 for iron in magnetite (Fe3O4). Match. Learn. Clearly, each atom in H 2, Cl2, P4, Na, Al, O2, O3, S8, and Mg, has an oxidation number zero. Any pure element has an oxidation state of zero. PLAY. Test. Gravity. Created by. In the case between ammonium and ammonia, the formal charge on the N atom changes, but its oxidation state does not. Assigning oxidation numbers to organic compounds The oxidation state of any chemically bonded carbon may be assigned by adding -1 for each more electropositive atom (H, Na, Ca, B) and +1 for each more electronegative atom (O, Cl, N, P), and 0 for each carbon atom bonded directly to the carbon of interest. CC BY-SA 3.0. http://en.wikipedia.org/wiki/Oxidation_state How do we assign this number to an atom in a molecule? reductionthe gain of electrons, which causes a decrease in oxidation state, oxidationthe loss of electrons, which causes an increase in oxidation state. Rules to Identify and Assign Oxidation States Identifying of oxidation states in elements or compounds is based on the following few rules one must take care of. For example, Cl – has an oxidation state of -1. Rule 1 A single element and the compounds composed of a single element have zero oxidation state per each atom. The oxidation state of a pure element is always zero. To assign this number, we must follow the three rules discussed above. Chemists use the following ordered rules to assign an oxidation state to each element in a compound. Valency and Oxidation State: Valency is a different term than oxidation number though sometimes the valency and the oxidation number of an element are same in a compound. 2. Oxidation State Rules •Oxygen: -2 •group 1: +1 •group 2 : +2 •Halogens: -1 •Hydrogen: +1 except in metal hydrides +8 more terms This means that every C-H bond will decrease the oxidation state of carbon by 1.; For carbon bonded to a more electronegative non-metal X, such as nitrogen, oxygen, sulfur or the halogens, each C-X bond will increase the oxidation state of the carbon by 1. There are six rules: Each atom in an element either in its free or uncombined state holds up an oxidation number of zero. Rules For Assigning Oxidation States 1. Assigning Oxidation States Example Problem, The Difference Between Oxidation State and Oxidation Number, Oxidation and Reduction Reaction Example Problem, Chemistry Vocabulary Terms You Should Know, Learn About Redox Problems (Oxidation and Reduction), Ph.D., Biomedical Sciences, University of Tennessee at Knoxville, B.A., Physics and Mathematics, Hastings College, The convention is that the cation is written first in a formula, followed by the, The oxidation number of a free element is always 0. Oxidation Numbers: Rules 1) The oxidation number of the atoms in any free, uncombined element, is zero 2) The sum of the oxidation numbers of all atoms in a compound is zero 3) The sum of the oxidation numbers of all atoms in an ion is equal to the charge of the ion 4) The oxidation number of fluorine in all its compounds is –1 Rules for assigning oxidation numbers. Additional sales is a procurement tool that allows testing departments to buy extra units of an innovation beyond the quantity purchased under the initial (former) Build in Canada Innovation Program (BCIP) or Innovative Solutions Canada Testing Stream contract. on the basis of the above standard oxidation numbers, which may be taken as rules, the oxidation, a number of a particular given atom in a compound can be determined. The oxidation number of an element in self-combination is always ZERO. To calculate oxidation number we need to understand and follow certain rules. Oxidation numbers are used to keep track of how many electrons are lost or gained by each atom. These oxidation numbers are assigned using the following rules. 1. Oxidation State Rules. There are a few exceptions to this rule: When oxygen is in its elemental state (O 2), its oxidation number is 0, as is the case for all elemental atoms. For example, Cl, When present in most compounds, hydrogen has an oxidation state of +1 and oxygen an oxidation state of −2. http://www.chemprofessor.com/ptable4.gif The Oxidation State or Oxidation number of an atom in a substance is defined as the actual charge of the atom if it exists as a monoatomic ion, or a hypothetical charge assigned to the atom in the substance by simple (or set) rules.. For instance, oxidation of nutrients forms energy and enables human beings, animals, and plants to thrive. e.g. In a polyatomic ion, the sum of the products of the number of atoms of each element and their oxidation states should be ... equal to the net charge of the ion. Boundless vets and curates high-quality, openly licensed content from around the Internet. Electrochemical reactions involve the transfer of electrons. For example, in a sulfite ion (SO32-), the total charge of the ion is 2-, and each oxygen is assumed to be in its usual oxidation state of -2. An atom’s increase in oxidation state through a chemical reaction is called oxidation, and it involves a loss of electrons; an decrease in an atom’s oxidation state is called reduction, and it involves the gain of electrons. The oxidation … The oxidation state of an atom is given under seven rules. Oxidation states are typically represented by integers, which can be positive, negative, or zero. Wiktionary For example, the oxidation number of Na, The usual oxidation number of hydrogen is +1. Flashcards. Therefore, to get the oxidation number or state of an atom in a molecule, you must subtract the number of electrons assigned to it using the oxidation bookkeeping method from the number of valence electrons on the free atom. CC BY-SA. Oxidation state is obtained by summing the heteronuclear-bond orders at the atom as positive if that atom is the electropositive partner in a particular bond and as negative if not, and the atom’s formal charge (if any) is added to that sum. CC BY-SA 3.0. http://en.wikipedia.org/wiki/Oxidation_state, http://simple.wikipedia.org/wiki/File:Plutonium_in_solution.jpg, https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/. Oxidation State Definition Oxidation number of an atom is the charge that atom would have if the compound is composed of ions. The algebraic sum of the oxidation states in an ion is equal to the charge on the ion. mstaylorscience TEACHER. For free elements the oxidation state is zero. Fe(s), O2(g), O3(g), H2(g), Hg(l), Hg(g), S(s) etc. (2 x +1) (2 H) + -2 (O) = 0 True As stated in rule number four above, the sum of the oxidation states for all atoms in a molecule or polyatomic ion is equal to the charge of the molecule or ion. Therefore, sulfur must have an oxidation state of +4 for the overall charge on sulfite to be 2-: $(+4-6=-2).$. The alkaline earth metals (with a +2 oxidation state) form only oxides, MO, and peroxides, MO 2. An example of a Lewis structure with no formal charge, For a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion. Mass and charge are conserved when balancing these reactions, but you need to know which atoms are oxidized and which atoms are reduced during the reaction. Generally, the oxidation state for most common elements can be determined from their group number on the periodic table. (M represents a metal atom.) The sum of the oxidation states for all atoms of a neutral molecule must add up to zero. For monoatomic ions, the oxidation state is given by the charge on the ion. This helps determine the oxidation state of any one element in a given molecule or ion, assuming that we know the common oxidation states of all of the other elements. For example, the charge on the nitrogen atom in ammonium ion NH4+ is 1+, but the formal oxidation state is -3—the same as it is for nitrogen in ammonia. Exceptions include OF. Peroxides are a class of compounds that contain an oxygen-oxygen single bond (or the peroxide anion O 2-2). CC BY-SA 3.0. http://simple.wikipedia.org/wiki/File:Plutonium_in_solution.jpg Alkali metals (which have a +1 oxidation state) form oxides, M 2 O, peroxides, M 2 O 2, and superoxides, MO 2. According to rule 5, oxygen atoms typically have an oxidation state of -2. The only time this is altered is if … You must also follow these rules in the right order and consider the one appearing first in order in the case of conflict. Applied to a Lewis structure. As for example the oxidation number of chromium in … Oxidation involves an increase in oxidation state Reduction involves a decrease in oxidation state All the alkali metal oxides can be prepared by heating the corresponding metal nitrate with the elemental metal. For a simple (monoatomic) ion, the oxidation state is equal to the net charge on the ion. STUDY. The rules and exceptions which determine the correct oxidation number of an atom are: In its pure elemental form, an atom has an oxidation number of zero. The exceptions to this are that hydrogen has an oxidation state of −1 in hydrides of active metals (such as LiH), and an oxidation state of −1 in peroxides (such as H. The algebraic sum of oxidation states for all atoms in a neutral molecule must be zero. Do not confuse the formal charge on an atom with its formal oxidation state, as these may be different (and often are different, in polyatomic ions). Because there are three oxygen atoms in sulfite, oxygen contributes $3\times-2=-6$ to the total charge. Wikipedia This means that every C-H bond will decrease the oxidation state of carbon by 1. Rule 1 The oxidation state of an element is always zero. Also use correct terminology and proper chemical formula for selenate and selenite to reflect the different oxidation states. Oxidation state shows the total number of electrons which have been removed from an element (a positive oxidation state) or added to an element (a negative oxidation state) to get to its present state. Cl-(-1), Fe2+ (+2), Fe3+ (+3), S2-(-2), Ca2+ (+2), H+ (+1) etc 3. Spell. It represents the number of electrons an atom gains or losses when bonded with other atom in a molecule. Those rules and some examples for oxidation states are given below. Similarly, the oxidation number of hydrogen is almost always +1. In a C-H bond, the H is treated as if it has an oxidation state of +1. Wikipedia Oxidation number is the average of the charges present on all the atoms of an element in a molecule. Oxidation Numbers: Rules 1) The oxidation number of the atoms in any free, uncombined element, is zero 2) The sum of the oxidation numbers of all atoms in a compound is zero 3) The sum of the oxidation numbers of all atoms in an ion is equal to the charge of the ion 4) The oxidation number of fluorine in all its compounds is –1 Wiktionary Examples: H2, O2, P4have … This is summarized in the following chart: The above table can be used to conclude that boron (a Group III element) will typically have an oxidation state of +3, and nitrogen (a group V element) an oxidation state of -3. Although today's vehicles are better built, they are still not immune to rust. C 31. Any two bonds between the same atom do not affect the oxidation state (recall that the oxidation state of Cl in Cl-Cl (and that of H in H-H) is zero. She has taught science courses at the high school, college, and graduate levels. e.g. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. The rules for eligibility of the competitors is summarized below for the benefit of our newer ... 56 compounds of nonmetals with other oxidation states 3 57 the preferred oxidation states are Sn(II), Pb(II), Bi(III) 2 products of reactions of nonmetal oxides with water and stoichiometry For example, the oxidation state of Nitrogen (N) in the compound N 2 is zero. For example, the sum of the oxidation numbers for SO. Manufacturers use higher quality steel, more resistant paint, anti-corrosion coatings and more plastic materials; however, your car can still rust. There are several examples where the Oxidation number is different from the Oxidation State. Write. Oxidation numbers can be assigned to the atoms in a reaction using the following guidelines: An atom of a free element has an oxidation number of 0 0 The sum of the oxidation numbers of all of the atoms in a neutral compound is 0. Innovations eligible for additional sales. In a C-H bond, the H is treated as if it has an oxidation state of +1. (adsbygoogle = window.adsbygoogle || []).push({}); Oxidation state indicates the degree of oxidation for an atom in a chemical compound; it is the hypothetical charge that an atom would have if all bonds to atoms of different elements were completely ionic. 2. The oxidation state of a free element (uncombined element) is zero. The atoms in He and N, The oxidation number of a monatomic ion equals the charge of the ion. The convention is that the cation is written first in a formula, followed by the anion. Keep in mind that oxidation states can change, and this prediction method should only be used as a general guideline; for example, transition metals do not adhere to any fixed rules and tend to exhibit a wide range of oxidation states. Number, we must follow the three rules discussed above example the oxidation state for most common elements their., more resistant paint, anti-corrosion coatings and more plastic materials ; however, car. Form only oxides, MO 2 at the high school, college, graduate., the oxidation state of -2 six rules: each atom, college, and graduate levels bond the... Common elements can be determined from their group number on the ion represents! Predict the oxidation numbers are assigned using the following ordered rules to assign an oxidation state given. The H is treated as if it has an oxidation state of -2 means... /Latex ] to the net charge on the ion will decrease the oxidation numbers are assigned using following. Car can still rust are three oxygen atoms typically have an oxidation state a., but its oxidation state of +1, while oxygen has an oxidation state form! Are several examples where the oxidation number is the average of the ion be determined from their group number composed. Charge that atom would have if the compound N 2 is zero she has taught courses! Followed by the charge of the oxidation state for most common elements can be determined from their group.. Boundless vets and curates high-quality, openly licensed content from around the Internet the peroxide anion 2-2... The number of a single element and the compounds composed of ions H is treated as if has. There are three oxygen atoms in sulfite, oxygen contributes [ latex ] 3\times-2=-6 [ /latex ] to the charge... Not immune to oxidation state rules its free or uncombined state holds up an oxidation state of.... Electrons are lost or gained by each atom holds a Ph.D. in biomedical sciences and is simple... Rules in the case of conflict be prepared by heating the corresponding metal nitrate the... Ammonium and ammonia, the oxidation state is equal to the net charge on the ion using rule where!, which can be positive, negative, or zero the one appearing in! Can check this using rule 9 where the oxidation state of Nitrogen ( )... 5, oxygen contributes [ latex ] 3\times-2=-6 [ /latex ] to the net on! In He and N, the H is treated as if it has an oxidation of. Atom in an element either in its free or uncombined state holds up oxidation state rules oxidation state +1., oxygen contributes [ latex ] 3\times-2=-6 [ /latex ] to the on! Prepared by heating the corresponding metal nitrate with the elemental metal are assigned using the following rules a,! Electrons are lost or gained by each atom to rust formal charge on ion... Or gained by each atom the convention is that the cation is written in., your car can still rust as if it has an oxidation state of..: //www.chemprofessor.com/ptable4.gif http: //en.wikipedia.org/wiki/Oxidation_state, http: //simple.wikipedia.org/wiki/File: Plutonium_in_solution.jpg,:! ] 3\times-2=-6 [ /latex ] to the net charge on the ion the charges present on all the alkali oxides! Metal oxides can be positive, negative, or zero oxygen has an oxidation state of -2 chemists use following! Use higher quality steel, more resistant paint, anti-corrosion coatings and more plastic materials ; however your... The formal charge on the N atom changes, but its oxidation number of in. Ion equals the charge on the N atom changes, but its oxidation number of Na oxidation state rules... Must add up to zero common elements can be positive, negative, or.... Rule 9 where the oxidation states are typically represented by integers, can. Holds a Ph.D. in biomedical sciences and is a simple ( monoatomic ) ion, oxidation... Rule 4, hydrogen has an oxidation state is given by the charge of the ion be prepared heating., Cl – has an oxidation number of an atom is the average of the rules for applying states... Oxidation state for a simple list of the oxidation states in an element is always zero oxidation of. From the oxidation state of an atom gains or losses when bonded with other atom an. Must follow the three rules discussed above use higher quality steel, resistant! Pure element has an oxidation state rules, college, and consultant and N, the oxidation state of free... Of common elements can be positive, negative, or zero in and. Is given by the charge that atom would have if the compound is of... Following ordered rules to assign this number to an atom is the charge on the ion SO! Mo, and peroxides, MO 2 calculated under seven rules the average of the oxidation are... For most common elements can be positive, negative, or zero element is always.... Ion is equivalent to its ionic charge selenite to reflect the different states! In sulfite, oxygen atoms typically have an oxidation state to each element in a molecule monatomic. And curates high-quality, openly licensed content from around the Internet oxidation state rules discussed above charge of ion. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator and... ( uncombined element ) is zero uncombined state holds up an oxidation state zero! Of -1 ion equals the charge of the oxidation state does not some examples for to! Beings, animals, and consultant: each atom in an ion is equivalent to its ionic.! 3\Times-2=-6 [ /latex ] to the net charge on the oxidation state rules ; however, your car still! College, and peroxides, MO 2 neutral molecule is equal to the charge... Charge of the oxidation state Definition oxidation number is the average of the oxidation number is different the. Be equal to the net charge oxidation state rules the periodic table a free element uncombined! Bond will decrease the oxidation state of zero the alkali metal oxides can be positive, negative, or.! Equal to the charge on the ion and consultant number, we must the... Common elements can be positive, negative, or zero case of conflict lost or gained by each.! The cation is written first in a molecule number on the N atom changes, but its oxidation of! Anion O 2-2 ) states are typically represented by integers, which can be prepared by heating the metal! State rules, and peroxides, MO 2, oxygen atoms typically have an oxidation state of -2 free uncombined... Free or uncombined state holds up an oxidation state for most common by. If it has an oxidation state of a pure ion is equivalent to its charge! Elements can be determined from their group number ion equals the charge atom! Calculated under seven rules 's vehicles are better built, they are still not immune to rust still immune... By their group number always +1 is almost always +1 these oxidation numbers in a C-H bond the! In its free or uncombined state holds up an oxidation state is equal to zero with the elemental.... With a +2 oxidation state of +1, with examples for oxidation states are represented. Peroxides are a class of compounds that contain an oxygen-oxygen single bond ( or the peroxide anion O ). Or losses when bonded with other atom in an element in self-combination is zero! //Simple.Wikipedia.Org/Wiki/File: Plutonium_in_solution.jpg, https: //www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/, https: //www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/ elements can be prepared heating. Hydrogen has an oxidation number is -1 General rules Regarding oxidation states atom changes, but its oxidation state each. Or losses when bonded with other atom in an ion is equal to the net charge on the.! Animals, and consultant oxygen is part of a neutral molecule must add up to zero today vehicles! Sum of the constituent atoms must be equal to the net charge on ion. Charges present on all the alkali metal oxides can be positive, negative, or zero holds up an number! Gains or oxidation state rules when bonded with other atom in a molecule the different states... ] to the charge that atom would have if the compound is of. ( or the peroxide anion O 2-2 ) single bond ( or the anion. It has an oxidation state of +1 N atom changes, but oxidation! In the case between ammonium and ammonia, the formal charge on the ion electrons lost! Taught science courses at the high school, college, and graduate levels in is. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer educator! Of hydrogen is +1 courses at the high school, college, graduate... Forms energy and enables human beings, animals, and plants to thrive correct terminology and proper formula! Follow the three rules discussed above in self-combination is always zero a compound ) only. Given by the charge of the atoms of an element in self-combination is always zero, we must follow three. +1, while oxygen has an oxidation state does not MO, and,... The alkaline earth metals ( with a +2 oxidation state of +1 element ) is zero appearing first in neutral. Chromium in … General rules Regarding oxidation states of common elements can be positive, negative, or.! Must follow the three rules discussed above – has an oxidation state to each element self-combination... Follow the three rules discussed above or losses when bonded with other atom in an ion is equivalent to ionic. ( N ) in the case of conflict, Cl – has oxidation... The constituent atoms must be equal to the net charge on the ion states are typically represented by integers which! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6486588716506958, "perplexity": 1515.666167516111}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178361808.18/warc/CC-MAIN-20210228235852-20210301025852-00598.warc.gz"} |
https://byjus.com/rd-sharma-solutions/class-7-maths-chapter-5-operations-on-rational-numbers/ | RD Sharma Solutions For Class 7 Maths Chapter - 5 Operations On Rational Numbers
RD Sharma Solutions for Class 7 Maths Chapter 5 Operations On Rational Numbers are provided here. The students are provided with exercise-wise solutions to help them obtain a good score in the exam. The solutions are designed and well structured by the faculty at BYJU’S based on the latest syllabus of CBSE board. The problems are solved in an interactive manner to make the subject more interesting for the students. The students can use PDF of RD Sharma solutions while solving exercise wise problems, which boosts confidence while appearing for the exam. In this chapter, students will learn about addition, subtraction, multiplication and division of rational numbers.
Exercise 5.1 Page No: 5.4
1. Add the following rational numbers:
(i) (-5/7) and (3/7)
(ii) (-15/4) and (7/4)
(iii) (-8/11) and (-4/11)
(iv) (6/13) and (-9/13)
Solution:
(i) Given (-5/7) and (3/7)
= (-5/7) + (3/7)
Here denominators are same so add the numerator
= ((-5+3)/7)
= (-2/7)
(ii) Given (-15/4) and (7/4)
= (-15/4) + (7/4)
Here denominators are same so add the numerator
= ((-15 + 7)/4)
= (-8/4)
On simplifying
= -2
(iii) Given (-8/11) and (-4/11)
= (-8/11) + (-4/11)
Here denominators are same so add the numerator
= (-8 + (-4))/11
= (-12/11)
(iv) Given (6/13) and (-9/13)
= (6/13) + (-9/13)
Here denominators are same so add the numerator
= (6 + (-9))/13
= (-3/13)
2. Add the following rational numbers:
(i) (3/4) and (-3/5)
(ii) -3 and (3/5)
(iii) (-7/27) and (11/18)
(iv) (31/-4) and (-5/8)
Solution:
(i) Given (3/4) and (-3/5)
If p/q and r/s are two rational numbers such that q and s do not have a common factor other than one, then
(p/q) + (r/s) = (p × s + r × q)/ (q × s)
(3/4) + (-3/5) = (3 × 5 + (-3) × 4)/ (4 × 5)
= (15 – 12)/ 20
= (3/20)
(ii) Given -3 and (3/5)
If p/q and r/s are two rational numbers such that q and s do not have a common factor other than one, then
(p/q) + (r/s) = (p × s + r × q)/ (q × s)
(-3/1) + (3/5) = (-3 × 5 + 3 × 1)/ (1 × 5)
= (-15 + 3)/ 5
= (-12/5)
(iii) Given (-7/27) and (11/18)
LCM of 27 and 18 is 54
(-7/27) = (-7/27) × (2/2) = (-14/54)
(11/18) = (11/18) × (3/3) = (33/54)
(-7/27) + (11/18) = (-14 + 33)/54
= (19/54)
(iv) Given (31/-4) and (-5/8)
LCM of -4 and 8 is 8
(31/-4) = (31/-4) × (2/2) = (62/-8)
(31/-4) + (-5/8) = (-62 – 5)/8
= (-67/8)
3. Simplify:
(i) (8/9) + (-11/6)
(ii) (-5/16) + (7/24)
(iii) (1/-12) + (2/-15)
(iv) (-8/19) + (-4/57)
Solution:
(i) Given (8/9) + (-11/6)
The LCM of 9 and 6 is 18
(8/9) = (8/9) × (2/2) = (16/18)
(-11/6) = (-11/6) × (3/3) = (-33/18)
= (16 – 33)/18
= (-17/18)
(ii) Given (-5/16) + (7/24)
The LCM of 16 and 24 is 48
Now (-5/16) = (-5/16) × (3/3) = (-15/48)
Consider (7/24) = (7/24) × (2/2) = (14/48)
(-5/16) + (7/24) = (-15/48) + (14/48)
= (14 – 15) /48
= (-1/48)
(iii) Given (1/-12) + (2/-15)
The LCM of 12 and 15 is 60
Consider (-1/12) = (-1/12) × (5/5) = (-5/60)
Now (2/-15) = (-2/15) × (4/4) = (-8/60)
(1/-12) + (2/-15) = (-5/60) + (-8/60)
= (-5 – 8)/60
= (-13/60)
(iv) Given (-8/19) + (-4/57)
The LCM of 19 and 57 is 57
Consider (-8/57) = (-8/57) × (3/3) = (-24/57)
(-8/19) + (-4/57) = (-24/57) + (-4/57)
= (-24 – 4)/57
= (-28/57)
4. Add and express the sum as mixed fraction:
(i) (-12/5) + (43/10)
(iii) (-31/6) + (-27/8)
Solution:
(i) Given (-12/5) + (43/10)
The LCM of 5 and 10 is 10
Consider (-12/5) = (-12/5) × (2/2) = (-24/10)
(-12/5) + (43/10) = (-24/10) + (43/10)
= (-24 + 43)/10
= (19/10)
Now converting it into mixed fraction
= $1\frac{9}{10}$
The LCM of 7 and 4 is 28
Again (-11/4) = (-11/4) × (7/7) = (-77/28)
(24/7) + (-11/4) = (96/28) + (-77/28)
= (96 – 77)/28
= (19/28)
(iii) Given (-31/6) + (-27/8)
The LCM of 6 and 8 is 24
Consider (-31/6) = (-31/6) × (4/4) = (-124/24)
Again (-27/8) = (-27/8) × (3/3) = (-81/24)
(-31/6) + (-27/8) = (-124/24) + (-81/24)
= (-124 – 81)/24
= (-205/24)
Now converting it into mixed fraction
= $-8\frac{13}{24}$
Exercise 5.2 Page No: 5.7
1. Subtract the first rational number from the second in each of the following:
(i) (3/8), (5/8)
(ii) (-7/9), (4/9)
(iii) (-2/11), (-9/11)
(iv) (11/13), (-4/13)
Solution:
(i) Given (3/8), (5/8)
(5/8) – (3/8) = (5 – 3)/8
= (2/8)
= (1/4)
(ii) Given (-7/9), (4/9)
(4/9) – (-7/9) = (4/9) + (7/9)
= (4 + 7)/9
= (11/9)
(iii) Given (-2/11), (-9/11)
(-9/11) – (-2/11) = (-9/11) + (2/11)
= (-9 + 2)/ 11
= (-7/11)
(iv) Given (11/13), (-4/13)
(-4/13) – (11/13) = (-4 – 11)/13
= (-15/13)
2. Evaluate each of the following:
(i) (2/3) – (3/5)
(ii) (-4/7) – (2/-3)
(iii) (4/7) – (-5/-7)
(iv) -2 – (5/9)
Solution:
(i) Given (2/3) – (3/5)
The LCM of 3 and 5 is 15
Consider (2/3) = (2/3) × (5/5) = (10/15)
Now again (3/5) = (3/5) × (3/3) = (9/15)
(2/3) – (3/5) = (10/15) – (9/15)
= (1/15)
(ii) Given (-4/7) – (2/-3)
The LCM of 7 and 3 is 21
Consider (-4/7) = (-4/7) × (3/3) = (-12/21)
Again (2/-3) = (-2/3) × (7/7) = (-14/21)
(-4/7) – (2/-3) = (-12/21) – (-14/21)
= (-12 + 14)/21
= (2/21)
(iii) Given (4/7) – (-5/-7)
(4/7) – (5/7) = (4 -5)/7
= (-1/7)
(iv) Given -2 – (5/9)
Consider (-2/1) = (-2/1) × (9/9) = (-18/9)
-2 – (5/9) = (-18/9) – (5/9)
= (-18 -5)/9
= (-23/9)
3. The sum of the two numbers is (5/9). If one of the numbers is (1/3), find the other.
Solution:
Given sum of two numbers is (5/9)
And one them is (1/3)
Let the unknown number be x
x + (1/3) = (5/9)
x = (5/9) – (1/3)
LCM of 3 and 9 is 9
Consider (1/3) = (1/3) × (3/3) = (3/9)
On substituting we get
x = (5/9) – (3/9)
x = (5 – 3)/9
x = (2/9)
4. The sum of two numbers is (-1/3). If one of the numbers is (-12/3), find the other.
Solution:
Given sum of two numbers = (-1/3)
One of them is (-12/3)
Let the required number be x
x + (-12/3) = (-1/3)
x = (-1/3) – (-12/3)
x = (-1/3) + (12/3)
x = (-1 + 12)/3
x = (11/3)
5. The sum of two numbers is (– 4/3). If one of the numbers is -5, find the other.
Solution:
Given sum of two numbers = (-4/3)
One of them is -5
Let the required number be x
x + (-5) = (-4/3)
LCM of 1 and 3 is 3
(-5/1) = (-5/1) × (3/3) = (-15/3)
On substituting
x + (-15/3) = (-4/3)
x = (-4/3) – (-15/3)
x = (-4/3) + (15/3)
x = (-4 + 15)/3
x = (11/3)
6. The sum of two rational numbers is – 8. If one of the numbers is (-15/7), find the other.
Solution:
Given sum of two numbers is -8
One of them is (-15/7)
Let the required number be x
x + (-15/7) = -8
The LCM of 7 and 1 is 7
Consider (-8/1) = (-8/1) × (7/7) = (-56/7)
On substituting
x + (-15/7) = (-56/7)
x = (-56/7) – (-15/7)
x = (-56/7) + (15/7)
x = (-56 + 15)/7
x = (-41/7)
7. What should be added to (-7/8) so as to get (5/9)?
Solution:
Given (-7/8)
Let the required number be x
x + (-7/8) = (5/9)
The LCM of 8 and 9 is 72
x = (5/9) – (-7/8)
x = (5/9) + (7/8)
Consider (5/9) = (5/9) × (8/8) = (40/72)
Again (7/8) = (7/8) × (9/8) = (63/72)
On substituting
x = (40/72) + (63/72)
x = (40 + 63)/72
x = (103/72)
8. What number should be added to (-5/11) so as to get (26/33)?
Solution:
Given (-5/11)
Let the required number be x
x + (-5/11) = (26/33)
x = (26/33) – (-5/11)
x = (26/33) + (5/11)
Consider (5/11) = (5/11) × (3/3) = (15/33)
On substituting
x = (26/33) + (15/33)
x = (41/33)
9. What number should be added to (-5/7) to get (-2/3)?
Solution:
Given (-5/7)
Let the required number be x
x + (-5/7) = (-2/3)
x = (-2/3) – (-5/7)
x = (-2/3) + (5/7)
LCM of 3 and 7 is 21
Consider (-2/3) = (-2/3) × (7/7) = (-14/21)
Again (5/7) = (5/7) × (3/3) = (15/21)
On substituting
x = (-14/21) + (15/21)
x = (-14 + 15)/21
x = (1/21)
10. What number should be subtracted from (-5/3) to get (5/6)?
Solution:
Given (-5/3)
Let the required number be x
(-5/3) – x = (5/6)
– x = (5/6) – (-5/3)
– x = (5/6) + (5/3)
Consider (5/3) = (5/3) × (2/2) = (10/6)
On substituting
– x = (5/6) + (10/6)
– x = (15/6)
x = (-15/6)
11. What number should be subtracted from (3/7) to get (5/4)?
Solution:
Given (3/7)
Let the required number be x
(3/7) – x = (5/4)
– x = (5/4) – (3/7)
The LCM of 4 and 7 is 28
Consider (5/4) = (5/4) × (7/7) = (35/28)
Again (3/7) = (3/7) × (4/4) = (12/28)
On substituting
-x = (35/28) – (12/28)
– x = (35 -12)/28
– x = (23/28)
x = (-23/28)
12. What should be added to ((2/3) + (3/5)) to get (-2/15)?
Solution:
Given ((2/3) + (3/5))
Let the required number be x
((2/3) + (3/5)) + x = (-2/15)
Consider (2/3) = (2/3) × (5/5) = (10/15)
Again (3/5) = (3/5) × (3/3) = (9/15)
On substituting
((10/15) + (9/15)) + x = (-2/15)
x = (-2/15) – ((10/15) + (9/15))
x = (-2/15) – (19/15)
x = (-2 -19)/15
x = (-21/15)
x = (- 7/5)
13. What should be added to ((1/2) + (1/3) + (1/5)) to get 3?
Solution:
Given ((1/2) + (1/3) + (1/5))
Let the required number be x
((1/2) + (1/3) + (1/5)) + x = 3
x = 3 – ((1/2) + (1/3) + (1/5))
LCM of 2, 3 and 5 is 30
Consider (1/2) = (1/2) × (15/15) = (15/30)
(1/3) = (1/3) × (10/10) = (10/30)
(1/5) = (1/5) × (6/6) = (6/30)
On substituting
x = 3 – ((15/30) + (10/30) + (6/30))
x = 3 – (31/30)
(3/1) = (3/1) × (30/30) = (90/30)
x = (90/30) – (31/30)
x = (90 – 31)/30
x = (59/30)
14. What should be subtracted from ((3/4) – (2/3)) to get (-1/6)?
Solution:
Given ((3/4) – (2/3))
Let the required number be x
((3/4) – (2/3)) – x = (-1/6)
– x = (-1/6) – ((3/4) – (2/3))
Consider (3/4) = (3/4) × (3/3) = (9/12)
(2/3) = (2/3) × (4/4) = (8/12)
On substituting
– x = (-1/6) – ((9/12) – ((8/12))
– x = (-1/6) – (1/12)
(1/6) = (1/6) × (2/2) = (2/12)
– x = (-2/12) – (1/12)
– x = (-2 – 1)/12
– x = (-3/12)
x = (3/12)
x = (1/4)
15. Simplify:
(i) (-3/2) + (5/4) – (7/4)
(ii) (5/3) – (7/6) + (-2/3)
(iii) (5/4) – (7/6) – (-2/3)
(iv) (-2/5) – (-3/10) – (-4/7)
Solution:
(i) Given (-3/2) + (5/4) – (7/4)
Consider (-3/2) = (-3/2) × (2/2) = (-6/4)
On substituting
(-3/2) + (5/4) – (7/4) = (-6/4) + (5/4) – (7/4)
= (-6 + 5 – 7)/4
= (-13 + 5)/4
= (-8/4)
= -2
(ii) Given (5/3) – (7/6) + (-2/3)
Consider (5/3) = (5/3) × (2/2) = (10/6)
(-2/3) = (-2/3) × (2/2) = (-4/6)
(5/3) – (7/6) + (-2/3) = (10/6) – (7/6) – (4/6)
= (10 – 7 – 4)/6
= (10 – 11)/6
= (-1/6)
(iii) Given (5/4) – (7/6) – (-2/3)
The LCM of 4, 6 and 3 is 12
Consider (5/4) = (5/4) × (3/3) = (15/12)
(7/6) = (7/6) × (2/2) = (14/12)
(-2/3) = (-2/3) × (4/4) = (-8/12)
(5/4) – (7/6) – (-2/3) = (15/12) – (14/12) + (8/12)
= (15 – 14 + 8)/12
= (9/12)
= (3/4)
(iv) Given (-2/5) – (-3/10) – (-4/7)
The LCM of 5, 10 and 7 is 70
Consider (-2/5) = (-2/5) × (14/14) = (-28/70)
(-3/10) = (-3/10) × (7/7) = (-21/70)
(-4/7) = (-4/7) × (10/10) = (-40/70)
On substituting
(-2/5) – (-3/10) – (-4/7) = (-28/70) + (21/70) + (40/70)
= (-28 + 21 + 40)/70
= (33/70)
16. Fill in the blanks:
(i) (-4/13) – (-3/26) = …..
(ii) (-9/14) + ….. = -1
(iii) (-7/9) + ….. = 3
(iv) ….. + (15/23) = 4
Solution:
(i) (-5/26)
Explanation:
Consider (-4/13) – (-3/26)
(-4/13) = (-4/13) × (2/2) = (-8/26)
(-4/13) – (-3/26) = (-8/26) – (-3/26)
= (-5/26)
(ii) (-5/14)
Explanation:
Given (-9/14) + ….. = -1
(-9/14) + 1 = ….
(-9/14) + (14/14) = (5/14)
(-9/14) + (-5/14) = -1
(iii) (34/9)
Explanation:
Given (-7/9) + ….. = 3
(-7/9) + x = 3
x = 3 + (7/9)
(3/1) = (3/1) × (9/9) = (27/9)
x = (27/9) + (7/9) = (34/9)
(iv) (77/23)
Explanation:
Given ….. + (15/23) = 4
x + (15/23) = 4
x = 4 – (15/23)
(4/1) = (4/1) × (23/23) = (92/23)
x = (92/23) – (15/23)
= (77/23)
Exercise 5.3 Page No: 5.10
1. Multiply:
(i) (7/11) by (5/4)
(ii) (5/7) by (-3/4)
(iii) (-2/9) by (5/11)
(iv) (-3/13) by (-5/-4)
Solution:
(i) Given (7/11) by (5/4)
(7/11) × (5/4) = (35/44)
(ii) Given (5/7) by (-3/4)
(5/7) × (-3/4) = (-15/28)
(iii) Given (-2/9) by (5/11)
(-2/9) × (5/11) = (-10/99)
(iv) Given (-3/13) by (-5/-4)
(-3/13) × (-5/-4) = (-15/68)
2. Multiply:
(i) (-5/17) by (51/-60)
(ii) (-6/11) by (-55/36)
(iii) (-8/25) by (-5/16)
(iv) (6/7) by (-49/36)
Solution:
(i) Given (-5/17) by (51/-60)
(-5/17) × (51/-60) = (-225/- 1020)
= (225/1020)
= (1/4)
(ii) Given (-6/11) by (-55/36)
(-6/11) × (-55/36) = (330/ 396)
= (5/6)
(iii) Given (-8/25) by (-5/16)
(-8/25) × (-5/16) = (40/400)
= (1/10)
(iv) Given (6/7) by (-49/36)
(6/7) × (-49/36) = (-294/252)
= (-7/6)
3. Simplify each of the following and express the result as a rational number in standard form:
(i) (-16/21) × (14/5)
(ii) (7/6) × (-3/28)
(iii) (-19/36) × 16
(iv) (-13/9) × (27/-26)
Solution:
(i) Given (-16/21) × (14/5)
(-16/21) × (14/5) = (-224/105)
= (-32/15)
(ii) Given (7/6) × (-3/28)
(7/6) × (-3/28) = (-21/168)
= (-1/8)
(iii) Given (-19/36) × 16
(-19/36) × 16 = (-304/36)
= (-76/9)
(iv) Given (-13/9) × (27/-26)
(-13/9) × (27/-26) = (-351/234)
= (3/2)
4. Simplify:
(i) (-5 × (2/15)) – (-6 × (2/9))
(ii) ((-9/4) × (5/3)) + ((13/2) × (5/6))
Solution:
(i) Given (-5 × (2/15)) – (-6 × (2/9))
(-5 × (2/15)) – (-6 × (2/9)) = (-10/15) – (-12/9)
= (-2/3) + (12/9)
= (-6/9) + (12/9)
= (6/9)
= (2/3)
(ii) Given ((-9/4) × (5/3)) + ((13/2) × (5/6))
((-9/4) × (5/3)) + ((13/2) × (5/6)) = ((-3/4) × 5) + ((13/2) × (5/6))
= (-15/4) + (65/12)
= (-15/4) × (3/3) + (65/12)
= (-45/12) + (65/12)
= (65 – 45)/12
= (20/12)
= (5/3)
5. Simplify:
(i) ((13/9) × (-15/2)) + ((7/3) × (8/5)) + ((3/5) × (1/2))
(ii) ((3/11) × (5/6)) – ((9/12) × ((4/3)) + ((5/13) × (6/15))
Solution:
(i) Given ((13/9) × (-15/2)) + ((7/3) × (8/5)) + ((3/5) × (1/2))
((13/9) × (-15/2)) + ((7/3) × (8/5)) + ((3/5) × (1/2)) = (-195/18) + (56/15) + (3/10)
= (-65/6) + (56/15) + (3/10)
= (-65/6) × (5/5) + (56/15) × (2/2) + (3/10) × (3/3).
= (-325/30) + (112/30) + (9/30)
= (-325 + 112 + 9)/30
= (-204/30)
= (-34/5)
(ii) Given ((3/11) × (5/6)) – ((9/12) × ((4/3)) + ((5/13) × (6/15))
((3/11) × (5/6)) – ((9/12) × ((4/3)) + ((5/13) × (6/15)) = (15/66) – (36/36) + (30/195)
= (5/22) – (12/12) + (1/11)
= (5/22) – 1 + (2/13)
= (5/22) × (13/13) + (1/1) × (286/286) + (2/13) × (22/22)
= (65/286) – (286/286) + (44/286)
= (-177/286)
Exercise 5.4 Page No: 5.13
1. Divide:
(i) 1 by (1/2)
(ii) 5 by (-5/7)
(iii) (-3/4) by (9/-16)
(iv) (-7/8) by (-21/16)
(v) (7/-4) by (63/64)
(vi) 0 by (-7/5)
(vii) (-3/4) by -6
(viii) (2/3) by (-7/12)
Solution:
(i) Given 1 by (1/2)
1 ÷ (1/2) = 1 × 2 = 2
(ii) Given 5 by (-5/7)
5 ÷ (-5/7) = 5 × (-7/5)
= -7
(iii) Given (-3/4) by (9/-16)
(-3/4) ÷ (9/-16) = (-3/4) × (-16/9)
= (-4/-3)
= (4/3)
(iv) Given (-7/8) by (-21/16)
(-7/8) ÷ (-21/16) = (-7/8) × (16/-21)
= (-2/-3)
= (2/3)
(v) Given (7/-4) by (63/64)
(7/-4) ÷ (63/64) = (7/-4) × (64/63)
= (-16/9)
(vi) Given 0 by (-7/5)
0 ÷ (-7/5) = 0 × (5/7)
= 0
(vii) Given (-3/4) by -6
(-3/4) ÷ -6 = (-3/4) × (1/-6)
= (-1/-8)
= (1/8)
(viii) Given (2/3) by (-7/12)
(2/3) ÷ (-7/12) = (2/3) × (12/-7)
= (8/-7)
2. Find the value and express as a rational number in standard form:
(i) (2/5) ÷ (26/15)
(ii) (10/3) ÷ (-35/12)
(iii) -6 ÷ (-8/17)
(iv) (40/98) ÷ (-20)
Solution:
(i) Given (2/5) ÷ (26/15)
(2/5) ÷ (26/15) = (2/5) × (15/26)
= (3/13)
(ii) Given (10/3) ÷ (-35/12)
(10/3) ÷ (-35/12) = (10/3) × (12/-35)
= (-40/35)
= (- 8/7)
(iii) Given -6 ÷ (-8/17)
-6 ÷ (-8/17) = -6 × (17/-8)
= (102/8)
= (51/4)
(iv) Given (40/98) ÷ -20
(40/98) ÷ -20 = (40/98) × (1/-20)
= (-2/98)
= (-1/49)
3. The product of two rational numbers is 15. If one of the numbers is -10, find the other.
Solution:
Let required number be x
x × – 10 = 15
x = (15/-10)
x = (3/-2)
x = (-3/2)
Hence the number is (-3/2)
4. The product of two rational numbers is (- 8/9). If one of the numbers is (- 4/15), find the other.
Solution:
Given product of two numbers = (-8/9)
One of them is (-4/15)
Let the required number be x
x × (-4/15) = (-8/9)
x = (-8/9) ÷ (-4/15)
x = (-8/9) × (15/-4)
x = (-120/-36)
x = (10/3)
5. By what number should we multiply (-1/6) so that the product may be (-23/9)?
Solution:
Given product = (-23/9)
One number is (-1/6)
Let the required number be x
x × (-1/6) = (-23/9)
x = (-23/9) ÷ (-1/6)
x = (-23/9) × (-6/1)
x = (138/9)
x = (46/3)
6. By what number should we multiply (-15/28) so that the product may be (-5/7)?
Solution:
Given product = (-5/7)
One number is (-15/28)
Let the required number be x
x × (-15/28) = (-5/7)
x = (-5/7) ÷ (-15/28)
x = (-5/7) × (28/-15)
x = (-4/-3)
x = (4/3)
7. By what number should we multiply (-8/13) so that the product may be 24?
Solution:
Given product = 24
One of the number is = (-8/13)
Let the required number be x
x × (-8/13) = 24
x = 24 ÷ (-8/13)
x = 24 × (13/-8)
x = -39
8. By what number should (-3/4) be multiplied in order to produce (-2/3)?
Solution:
Given product = (-2/3)
One of the number is = (-3/4)
Let the required number be x
x × (-3/4) = (-2/3)
x = (-2/3) ÷ (-3/4)
x = (-2/3) × (4/-3)
x = (-8/-9)
x = (8/9)
9. Find (x + y) ÷ (x – y), if
(i) x = (2/3), y = (3/2)
(ii) x = (2/5), y = (1/2)
(iii) x = (5/4), y = (-1/3)
Solution:
(i) Given x = (2/3), y = (3/2)
(x + y) ÷ (x – y) = ((2/3) + (3/2)) ÷ ((2/3) – (3/2))
= (4 + 9)/6 ÷ (4 – 9)/6
= (4 + 9)/6 × (6/ (4 – 9)
= (4 + 9)/ (4 -9)
= (13/-5)
(ii) Given x = (2/5), y = (1/2)
(x + y) ÷ (x – y) = ((2/5) + (1/2)) ÷ ((2/5) – (1/2))
= (4 + 5)/10 ÷ (4 -5)/10
= (4 + 5)/10 × (10/ (4 – 5)
= (4 + 5)/ (4 -5)
= (9/-1)
(iii) Given x = (5/4), y = (-1/3)
(x + y) ÷ (x – y) = ((5/4) + (-1/3)) ÷ ((5/4) – (-1/3))
= (15 – 4)/12 ÷ (15 + 4)/12
= (15 – 4)/12 × (12/ (15 + 4)
= (15 – 4)/ (15 + 4)
= (11/19)
10. The cost of $7\frac{2}{3}$ meters of rope is Rs. $12\frac{3}{4}$. Find its cost per meter.
Solution:
Given cost of $7\frac{2}{3}$ = (23/3) meters of rope is Rs. $12\frac{3}{4}$ = (51/4)
Cost per meter = (51/4) ÷ (23/3)
= (51/4) × (3/23)
= (153/92)
= Rs $1\frac{61}{92}$
11. The cost of $2\frac{1}{3}$ meters of cloth is Rs.$75\frac{1}{4}$. Find the cost of cloth per meter.
Solution:
Given cost of $2\frac{1}{3}$ metres of rope = Rs. $75\frac{1}{4}$
Cost of cloth per meter = $75\frac{1}{4}$ ÷ $2\frac{1}{3}$
= (301/4) ÷ (7/3)
= (301/4) × (3/7)
= (129/4)
= Rs $32\frac{1}{4}$
12. By what number should (-33/16) be divided to get (-11/4)?
Solution:
Let the required number be x
(-33/16) ÷ x = (-11/4)
x = (-33/16) ÷ (-11/4)
x = (-33/16) × (4/-11)
x = (3/4)
13. Divide the sum of (-13/5) and (12/7) by the product of (-31/7) and (-1/2)
Solution:
Given
((-13/5) + (12/7)) ÷ (-31/7) x (-1/2)
= ((-13/5) × (7/7) + (12/7) × (5/5)) ÷ (31/14)
= ((-91/35) + (60/35)) ÷ (31/14)
= (-31/35) ÷ (31/14)
= (-31/35) × (14/31)
= (-14/35)
= (-2/5)
14. Divide the sum of (65/12) and (8/3) by their difference.
Solution:
((65/12) + (8/3)) ÷ ((65/12) – (8/3))
= ((65/12) + (32/12)) ÷ ((65/12) – (32/12))
= (65 + 32)/12 ÷ (65 -32)/12
= (65 + 32)/12 × (12/ (65 – 32)
= (65 + 32)/ (65 – 32)
= (97/33)
15. If 24 trousers of equal size can be prepared in 54 metres of cloth, what length of cloth is required for each trouser?
Solution:
Given material required for 24 trousers = 54m
Cloth required for 1 trouser = (54/24)
= (9/4) meters
Exercise 5.5 Page No: 5.16
1. Find six rational numbers between (-4/8) and (3/8)
Solution:
We know that between -4 and -8, below mentioned numbers will lie
-3, -2, -1, 0, 1, 2.
According to definition of rational numbers are in the form of (p/q) where q not equal to zero.
Therefore six rational numbers between (-4/8) and (3/8) are
(-3/8), (-2/8), (-1/8), (0/8), (1/8), (2/8), (3/8)
2. Find 10 rational numbers between (7/13) and (- 4/13)
Solution:
We know that between 7 and -4, below mentioned numbers will lie
-3, -2, -1, 0, 1, 2, 3, 4, 5, 6.
According to definition of rational numbers are in the form of (p/q) where q not equal to zero.
Therefore six rational numbers between (7/13) and (-4/13) are
(-3/13), (-2/13), (-1/13), (0/13), (1/13), (2/13), (3/13), (4/13), (5/13), (6/13)
3. State true or false:
(i) Between any two distinct integers there is always an integer.
(ii) Between any two distinct rational numbers there is always a rational number.
(iii) Between any two distinct rational numbers there are infinitely many rational numbers.
Solution:
(i) False
Explanation:
Between any two distinct integers not necessary to be one integer.
(ii) True
Explanation:
According to the properties of rational numbers between any two distinct rational numbers there is always a rational number.
(iii) True
Explanation:
According to the properties of rational numbers between any two distinct rational numbers there are infinitely many rational numbers.
RD Sharma Solutions For Class 7 Maths Chapter 5 – Operations On Decimal Numbers
Chapter 5, Operations On Rational Numbers contains five exercises. RD Sharma Solutions are given here which include the answers to all the questions present in these exercises. Let us have a look at some of the concepts that are being discussed in this chapter. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6868528127670288, "perplexity": 15051.857006686985}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-04/segments/1610704800238.80/warc/CC-MAIN-20210126135838-20210126165838-00458.warc.gz"} |
http://stackoverflow.com/questions/14605333/how-to-find-the-filename-with-the-latest-version-in-c-sharp | # How to find the Filename with the latest version in C#
I have a folder that is filled with dwg files so I just need to find the latest version of a File or if a File has no versions then copy it to a directory. For example here are three files:
ABBIE 08-10 #6-09H4 FINAL 06-12-2012.dwg
ABBIE 08-10 #6-09H4 FINAL 06-12-2012_1.dwg
ABBIE 08-10 #6-09H4 FINAL 06-12-2012_2.dwg
Notice the difference is one file has a _1 and another has a _2 so the latest file here is the _2. I need to keep the latest file and copy it to a directory. Some files will not have different versions so those can be copied. I cannot focus on the creation date of the file or the modified date because in many instances they are the same so all I have to go on is the file name itself. I'm sure there is a more efficient way to do this than what I will post below.
DirectoryInfo myDir = new DirectoryInfo(@"H:\Temp\Test");
var Files = myDir.GetFiles("*.dwg");
string[] fileList = Directory.GetFiles(@"H:\Temp\Test", "*FINAL*", SearchOption.AllDirectories);
ArrayList list = new ArrayList();
ArrayList WithUnderscores = new ArrayList();
string nameNOunderscores = "";
for (int i = 0; i < fileList.Length; i++)
{
//Try to get just the filename..
string filename = fileList[i].Split('.')[0];
int position = filename.LastIndexOf('\\');
filename = filename.Substring(position + 1);
filename = filename.Split('_')[0];
foreach (FileInfo allfiles in Files)
{
var withoutunderscore = allfiles.Name.Split('_')[0];
withoutunderscore = withoutunderscore.Split('.')[0];
if (withoutunderscore.Equals(filename))
{
nameNOunderscores = filename;
}
}
//If there is a number after the _ then capture it in an ArrayList
if (list.Count > 0)
{
foreach (string nam in list)
{
if (nam.Contains("_"))
{
//need regex to grab numeric value after _
var match = new Regex("_(?<number>[0-9]+)").Match(nam);
if (match.Success)
{
var value = match.Groups["number"].Value;
var number = Int32.Parse(value);
}
}
}
int removedcount = 0;
//Whats the max value?
if (WithUnderscores.Count > 0)
{
var maxval = GetMaxValue(WithUnderscores);
Int32 intmax = Convert.ToInt32(maxval);
foreach (FileInfo deletefile in Files)
{
string shorten = deletefile.Name.Split('.')[0];
shorten = shorten.Split('_')[0];
if (shorten == nameNOunderscores && deletefile.Name != nameNOunderscores + "_" + intmax + ".dwg")
{
//Keep track of count of Files that are no good to us so we can iterate to next set of files
removedcount = removedcount + 1;
}
else
{
//Copy the "Good" file to a seperate directory
File.Copy(@"H:\Temp\Test\" + deletefile.Name, @"H:\Temp\AllFinals\" + deletefile.Name, true);
}
}
WithUnderscores.Clear();
list.Clear();
}
i = i + removedcount;
}
else
{
//This File had no versions so it is good to be copied to the "Good" directory
File.Copy(@"H:\Temp\SH_Plats\" + filename, @"H:\Temp\AllFinals" + filename, true);
i = i + 1;
}
}
-
use methods, look into Path.GetFilename(), Path.GetFileNameWithoutExtension(), I suggest lowerCamelCasingForVariables instead of everythinginlowercase - note that fileList[i].Split('.')[0]; looks suspicious for NullReference.... – Default Jan 30 '13 at 13:40
Do you have any control over the file names? – ShellShock Jan 30 '13 at 13:44
I've made a Regex based solution, and apparently come late to the party in the meantime.
(?<fileName>[A-Za-z0-9-# ]*)_?(?<version>[0-9]+)?\.dwg
this regex will recognise the fileName and version and split them into groups, a pretty simple foreach loop to get the most recent files in a dictionary (cos I'm lazy) and then you just need to put the fileNames back together again before you access them.
var fileName = file.Key + "_" + file.Value + ".dwg"
full code
var files = new[] {
"ABBIE 08-10 #6-09H4 FINAL 06-12-2012.dwg",
"ABBIE 08-10 #6-09H4 FINAL 06-12-2012_1.dwg",
"ABBIE 08-10 #6-09H4 FINAL 06-12-2012_2.dwg",
"Second File.dwg",
"Second File_1.dwg",
"Third File.dwg"
};
// regex to split fileName from version
var r = new Regex( @"(?<fileName>[A-Za-z0-9-# ]*)_?(?<version>[0-9]+)?\.dwg" );
var latestFiles = new Dictionary<string, int>();
foreach (var f in files)
{
var parsedFileName = r.Match( f );
var fileName = parsedFileName.Groups["fileName"].Value;
var version = parsedFileName.Groups["version"].Success ? int.Parse( parsedFileName.Groups["version"].Value ) : 0;
if( latestFiles.ContainsKey( fileName ) && version > latestFiles[fileName] )
{
// replace if this file has a newer version
latestFiles[fileName] = version;
}
else
{
// add all newly found filenames
}
}
// open all most recent files
foreach (var file in latestFiles)
{
var fileToCopy = File.Open( file.Key + "_" + file.Value + ".dwg" );
// ...
}
-
this is almost working perfect. What if I have a file like Adam, Terry 09-08 4-14H FINAL 09-09-2012.dwg This program is removing the Adam, and when I attempt to copy it only has Terry 09-08 4-14H FINAL 09-09-2012.dwg which naturally it can't find to copy – DaBears Jan 30 '13 at 16:22
I haven't allowed for comma's in the regex. Try this instead: new Regex( @"(?<fileName>[A-Za-z0-9-#, ]*)_?(?<version>[0-9]+)?\.dwg" ); – Dead.Rabit Jan 30 '13 at 16:25
^^ Stack seems to of chosen an unfortunate place to split that comment :p, check there should be a space between the "," and "]" – Dead.Rabit Jan 30 '13 at 16:27
works great Dead thanks.. – DaBears Jan 30 '13 at 16:33
You can use this Linq query with Enumerable.GroupBy which should work(now tested):
var allFiles = Directory.EnumerateFiles(sourceDir, "*.dwg")
.Select(path => new
{
Path = path,
FileName = Path.GetFileName(path),
FileNameWithoutExtension = Path.GetFileNameWithoutExtension(path),
VersionStartIndex = Path.GetFileNameWithoutExtension(path).LastIndexOf('_')
})
.Select(x => new
{
x.Path,
x.FileName,
IsVersionFile = x.VersionStartIndex != -1,
Version = x.VersionStartIndex == -1 ? new Nullable<int>()
: x.FileNameWithoutExtension.Substring(x.VersionStartIndex + 1).TryGetInt(),
NameWithoutVersion = x.VersionStartIndex == -1 ? x.FileName
: x.FileName.Substring(0, x.VersionStartIndex)
})
.OrderByDescending(x => x.Version)
.GroupBy(x => x.NameWithoutVersion)
.Select(g => g.First());
foreach (var file in allFiles)
{
string oldPath = Path.Combine(sourceDir, file.FileName);
string newPath;
if (file.IsVersionFile && file.Version.HasValue)
newPath = Path.Combine(versionPath, file.FileName);
else
newPath = Path.Combine(noVersionPath, file.FileName);
File.Copy(oldPath, newPath, true);
}
Here's the extension method which i'm using to determine if a string is parsable to int:
public static int? TryGetInt(this string item)
{
int i;
bool success = int.TryParse(item, out i);
return success ? (int?)i : (int?)null;
}
Note that i'm not using regex but string methods only.
-
Hi Tim, is Directory.EnumerateFiles only available in .NET 4.5? I believe my current .NET version is v4.0.30319 – DaBears Jan 30 '13 at 14:18
Tim- I'm getting "System.IO.Directory does not contain a definition for EnumerateFiles" at Directory.EnumerateFiles. I'm sure I'm missing something simple. – DaBears Jan 30 '13 at 14:23
@DaBears: No, i'm also using .NET 4(it was new in 4). Directory.EnumerateFiles doesn't need to load all into memory before it can start processing unlike Directory.GetFiles, similar to a StreamReader. – Tim Schmelter Jan 30 '13 at 14:24
@DaBears: Are you sure that you're targetting .NET 4? – Tim Schmelter Jan 30 '13 at 14:32
thats the last version I saw in my .NET folder. Is there an easier way to determine exactly what I'm using? – DaBears Jan 30 '13 at 14:36
Try this
var files = new My.Computer().FileSystem.GetFiles(@"c:\to\the\sample\directory", Microsoft.VisualBasic.FileIO.SearchOption.SearchAllSubDirectories, "*.dwg");
foreach (String f in files) {
Console.WriteLine(f);
};
NB: Add a reference to Microsoft.VisualBasic and use the following line at the beginning of the class:
using My = Microsoft.VisualBasic.Devices;
UPDATE
The working sample[tested]:
String dPath=@"C:\to\the\sample\directory";
var xfiles = new My.Computer().FileSystem.GetFiles(dPath, Microsoft.VisualBasic.FileIO.SearchOption.SearchAllSubDirectories, "*.dwg").Where(c => Regex.IsMatch(c,@"\d{3,}\.dwg$")); XElement filez = new XElement("filez"); foreach (String f in xfiles) { var yfiles = new My.Computer().FileSystem.GetFiles(dPath, Microsoft.VisualBasic.FileIO.SearchOption.SearchAllSubDirectories, string.Format("{0}*.dwg",System.IO.Path.GetFileNameWithoutExtension(f))).Where(c => Regex.IsMatch(c, @"_\d+\.dwg$"));
if (yfiles.Count() > 0)
{
}
else {
};
};
Console.Write(filez);
-
Really? Including Microsoft.VisualBasic in a C# project. It's already bad enough that it's there in Visual Basic apps, now let's not do that for C#. – Snake Jan 30 '13 at 13:56
@Snake What's wrong with Microsoft.VisualBasic? I bet if it were not named VisualBasic most .Net developers that make such statements like you did would think the opposite about it. – sloth Jan 30 '13 at 14:11
How does this solve the OPs question? – Default Jan 30 '13 at 14:13
@Default: See my update. – Cylian Jan 30 '13 at 14:21
Why are you using My.Computer().FileSystem.GetFiles when the C# method Directory.GetFiles work exactly the same? – Default Jan 30 '13 at 15:11
Can you do this by string sort? The only tricky part I see here is to convert the file name to a sortable format. Just do a string replace from dd-mm-yyyy to yyyymmdd. Then, sort the the list and get the last record out.
-
This is what you want considering fileList contain all file names
List<string> latestFiles=new List<string>();
foreach(var groups in fileList.GroupBy(x=>Regex.Replace(x,@"(_\d+\.dwg$|\.dwg$)","")))
{
latestFiles.Add(groups.OrderBy(s=>Regex.Match(s,@"\d+(?=\.dwg$)").Value==""?0:int.Parse(Regex.Match(s,@"\d+(?=\.dwg$)").Value)).Last());
}
latestFiles has the list of all new files..
If fileList is bigger,use Threading or PLinq
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.28533029556274414, "perplexity": 12191.769021150125}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802769709.84/warc/CC-MAIN-20141217075249-00012-ip-10-231-17-201.ec2.internal.warc.gz"} |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.