URL
stringlengths 15
1.68k
| text_list
sequencelengths 1
199
| image_list
sequencelengths 1
199
| metadata
stringlengths 1.19k
3.08k
|
---|---|---|---|
https://www.vluchtschemas.nl/destinations.html | [
" Flight Schedules countries, flight schedules, flight numbers, flight days.\n\n Main menu Overview all Destinations with airlines and flightday Overview all airlines",
null,
"Nederlands English Deutsch Español Back\n\n Click on the country or airline for detailed information on flight times. Flight days Summer 2022 Winter 2022-2023 Country Destination Airline Daily Mo Tu We Th Fr Sa Su Daily Mo Tu We Th Fr Sa Su Argentina Buenos Aires (EZE) Air Europa x x British Airways x Iberia x x KLM / Air France x x Lufthansa x x Cordoba (COR) Air Europa x x x x x x Aruba Oranjestad (AUA) KLM / Air France x x TUI fly BE x TUI fly NL x x x x x x Barbados Bridgetown (BGI) KLM / Air France x x x Bolivia Santa Cruz (VVI) Air Europa x x x x Bonaire Kralendijk (BON) Air Belgium x x KLM / Air France x x TUI fly NL x x Brazil Fortaleza (FOR) Air Europa x x Recife (REC) Air Europa x x TAP Portugal x x Rio de Janeiro (GIG) British Airways x x x x x x x x x x KLM / Air France x x Lufthansa x x x x x x x x x x TAP Portugal x x Salvador de Bahia (SSA) Air Europa x x x TAP Portugal x x x x x x Sao Paulo (GRU) Air Europa x x British Airways x x x x x Iberia x x KLM / Air France x x Latam x x Lufthansa x x Swiss Airlines x x TAP Portugal x x Chile Santiago de Chile (SCL) Iberia x x KLM / Air France x x Colombia Bogota (BOG) Air Europa x x Avianca x x Delta Airlines x x Iberia x x KLM / Air France x x Lufthansa x x x x x x x x x x Cartagena (CTG) KLM / Air France x x x x x Cali (CLO) Avianca x x x x x x x x Medellin (MDE) Air Europa x x x x x x x x x Costa Rica Liberia (LIR) KLM / Air France x x x x San Jose (SJO) Aeromexico x x Air Europa x x x British Airways x x x Delta Airlines x x Iberia x x x x x x x x x x x x Iberojet x x x x x KLM / Air France x x Lufthansa x x x x x x Swiss Airlines x x x x x x United Airlines x x Cuba Havana (HAV) Air Caraïbes x x x Air Europa x x x x x x x Condor x x x Iberia x x x x x Iberojet x x x x x x x KLM / Air France x x TUI fly BE x x World2fly x x x x x x Holguin (HOG) Condor x x x Varadero (VRA) Condor x x x x x Eurowings Discover x x Iberojet x TUI fly BE x x x x TUI fly NL x x x x Curacao Willemstad (CUR) Air Belgium x x KLM / Air France x x TUI fly NL x x Dominican Republic Puerto Plata (POP) Condor x x x x Edelweis Air x x Eurowings Discover x Punta Cana (PUJ) Air Belgium x x x x Air Caraïbes x x x x x x x x x Air Europa x x x x x x x Condor x x x x x x x x x Edelweis Air x x x x Eurowings Discover x x x x x x x x x x x Iberojet x x x KLM / Air France x x x x x x x TAP Portugal x x x x x x TUI fly BE x x x x x x TUI fly NL x x x x Wamos Air x x x World2fly x x x x x x Santo Domingo (SDQ) Air Europa x x Condor x x Iberia x x TUI fly BE x x x KLM / Air France x x x x x x x x x Equador Guayaquil (GYE) Air Europa x x x Iberia x x x x x x x KLM / Air France x Quito (UIO) Air Europa x x x x x x Iberia x x x x x KLM / Air France x x Florida Miami (MIA) Air Europa x x x x x x x American Airlines x x British Airways x x Delta Airlines x x Iberia x x KLM / Air France x x Lufthansa x x Swiss Airlines x x TAP Portugal x x TUI fly BE x x United Airlines x x Orlando (MCO) British Airways x x Delta Airlines x x Lufthansa x x United Airlines x x Jamaica Montego Bay (MBJ) British Airways x x Condor x x Eurowings Discover x x x TUI fly BE x x TUI fly NL x x Martinique Fort de France (FDF) Air Belgium Mauricio Mauricio (MRU) Iberojet x Mexico Cancun (CUN) Aeromexico x x Air Europa x x x x x x x x Air Caraïbes x x x Condor x x x x x Delta Airlines x x Eurowings Discover x x x x x Iberojet x x x x x x x x KLM / Air France x x x TAP Portugal x x x x x x x x x x x TUI fly BE x x x x x x TUI fly NL x x x x United Airlines x x Wamos Air x x World2fly x x x x x x Guadalajara (GDL) Aeromexico x x x Los Cabos (SJD) Iberojet x Mexico City (MEX) Aeromexico x x Emirates x x Iberia x x KLM / Air France x x Lufthansa x x United Airlines x x Monterrey (MTY) Aeromexico x x x x x x Panama Panama city (PTY) Air Europa x x x x x x x x Eurowings Discover x x x x x x KLM / Air France x x Iberia x x x x x x Paraguay Asuncion (ASU) Air Europa x x x x x x x x x Peru Lima (LIM) Air Europa x x Iberia x x KLM / Air France x x Puerto Rico San Juan (SJU) Condor Delta Airlines x x Iberia x x x x x x x x x KLM / Air France x Saint Martin Philipsburg (SXM) Air Caraïbes x x x KLM / Air France x x Surinam Paramaribo (PBM) KLM / Air France x x x x x x x x x x Surinam Airways x x x x x x x x Trinidad & Tabago Port of Spain (POS) KLM / Air France x x x Uruguay Montevideo (MVD) Air Europa x x x x x x x x Iberia x x x x x x x Venezuela Caracas (CCS) Air Europa x x x Iberia x x x",
null,
"Home",
null,
"",
null,
"",
null,
"Menu Flight Schedules",
null,
""
] | [
null,
"https://www.vluchtschemas.nl/Flaggen/netherlands.gif",
null,
"https://www.vluchtschemas.nl/figures/boven.gif",
null,
"https://www.vluchtschemas.nl/Flaggen/netherlands.gif",
null,
"https://www.vluchtschemas.nl/Flaggen/england.gif",
null,
"https://www.vluchtschemas.nl/Flaggen/germany.gif",
null,
"https://www.vluchtschemas.nl/figures/boven.gif",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.7370002,"math_prob":1.0000025,"size":318,"snap":"2022-27-2022-33","text_gpt3_token_len":81,"char_repetition_ratio":0.17197452,"word_repetition_ratio":0.7241379,"special_character_ratio":0.24842767,"punctuation_ratio":0.10769231,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9951921,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12],"im_url_duplicate_count":[null,9,null,10,null,9,null,4,null,4,null,10,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-07-04T03:36:49Z\",\"WARC-Record-ID\":\"<urn:uuid:9acce650-e5c7-47e7-9d8e-078d2ea21c90>\",\"Content-Length\":\"267885\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:afd64b1e-737b-4b7a-a8a1-e37d7a8b2ddf>\",\"WARC-Concurrent-To\":\"<urn:uuid:547e7f82-2034-403c-8d6c-ac560d65cd06>\",\"WARC-IP-Address\":\"109.71.54.26\",\"WARC-Target-URI\":\"https://www.vluchtschemas.nl/destinations.html\",\"WARC-Payload-Digest\":\"sha1:T4SVXD4TTR2L7C7NTTKCDACF7JEAO5GG\",\"WARC-Block-Digest\":\"sha1:PSFKYR72CLPO7QSQGF4C77CRFXTLKKYL\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-27/CC-MAIN-2022-27_segments_1656104293758.72_warc_CC-MAIN-20220704015700-20220704045700-00022.warc.gz\"}"} |
https://igeeksmagz.com/mathsolving-584 | [
"# Personal math tutor near me\n\nKeep reading to understand more about Personal math tutor near me and how to use it. Our website can help me with math work.\n\n## The Best Personal math tutor near me\n\nApps can be a great way to help students with their algebra. Let's try the best Personal math tutor near me. Solve for x right triangles by using a Pythagorean formula. This calculator is useful for determining the length of a side of a right triangle, known as the hypotenuse. The Pythagorean relationship between sides x and y is: The ratio or proportion between sides x and y is given by: Substituting this into the above equation gives: or in other words: This can be simplified further as shown below: Therefore, solving for \"x\" right triangles involves applying this formula to any right triangle with lengths equal to 1, 2, and 3. If the hypotenuse (AB) is known then \"x\" can be determined from the equation. For example, if AB = 9 then \"x\" = 9. On the other hand, if AB = 16 then \"x\" = 16. For example, if AB = 12 then \"x\" = 12.\n\nIf an expression cannot be factored, then the process must begin again from scratch. Factoring is the process of breaking down an expression into two separate expressions, one of which has a common factor. . . If an expression cannot be factored, then the process must begin again from scratch. Factoring is done to solve equations when both sides of an equation have a common factor. An easy way to solve this type of equation is by using a combination of variables called a substitution method. A substitution method will take one side of the equation and substitute each variable for its corresponding term on the other side of the equation. The resulting equation will have one fewer term than there are variables in the original equation; this will usually lead to a simplified result with a smaller value for each variable.\n\nGraph equations are a common problem in mathematics. They are used to calculate the position of a point on a graph, for example. The goal is to solve for a specific value in a graph. Here, we will show you how to solve graph equations using Pythagoras' theorem. This method is often referred to as \"dot-to-dot.\" How to solve graph equations using Pythagoras' theorem If you have a triangle with vertices (A, B, and C) and you want to know the length of side AC, then use Pythagoras' theorem to solve for A: [AB=sqrt{AC}] Solution: Substitute the values and simplify: AB=2AC so [A=(-1)^2sqrt{AC}=(-1)sqrt{AC}] Solution: Substitute the values and simplify: A=-(1)AC so [B=(2)^2sqrt{AC}] Solution: Substitute the values and simplify: B=4AC so [C=(-1)^2sqrt{AC}] The rule of Pythagoras states that when solving for distance or ratio between two points, it's best to find their sum or difference first. For example, if you want to know how far 2 cars are apart from each other\n\nSolve with steps is one of the most popular types of puzzles. In this type, you must solve each step in sequence to reach the final solution. Solving with steps puzzles are great for people who want a quick yet challenging brain workout while also providing a sense of accomplishment. If you’re new to solving with steps, start off by simply counting out each step and then visualize yourself making your way through the puzzle. Once you have all the steps down, it will only take a few extra seconds to complete the puzzle. People unfamiliar with solving with steps often end up trying to count out each and every step when they should be focusing on just one or two steps at a time. This can quickly lead to frustration and confusion if you have a lot of information to process at once. Instead, focus on just one or two key steps that you need to remember and try to encode them in your memory as quickly as possible so that you can easily recall them later on.\n\nVery easy to use. Feel like there could be more options for different things. It just seems very minimal and basic, like take photo, solve, explain, done. Which is great, I just want to be able to write equations and such. But overall, def worth 5 stars,",
null,
"Jayda Kelly\nI love this app. I don't recommend to use this app for everything (since we should use our brain) but I use this at times when I don't understand something. It scans the problem properly, and at the end it has the solution and the strategy. It really helps me with homework. Great job, keep going.",
null,
"Ysabella Sanchez\nEllipse solver How to do a math problem Solving an algebra problem Solve each system by elimination solver Circle equation solver Free help with math"
] | [
null,
"https://igeeksmagz.com/aGU6320a40fd2d67/25388788904_72d2f5ec6f_z-150x150.jpg",
null,
"https://igeeksmagz.com/aGU6320a40fd2d67/team_3-150x150.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9412072,"math_prob":0.98289526,"size":3892,"snap":"2022-40-2023-06","text_gpt3_token_len":874,"char_repetition_ratio":0.10468107,"word_repetition_ratio":0.117221415,"special_character_ratio":0.22122303,"punctuation_ratio":0.08997429,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99823004,"pos_list":[0,1,2,3,4],"im_url_duplicate_count":[null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-02-03T03:52:00Z\",\"WARC-Record-ID\":\"<urn:uuid:f132db2d-3b2d-4c48-a956-b567c531af34>\",\"Content-Length\":\"25346\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:0bb7e3a3-b76c-49bf-ba98-f66627a584d4>\",\"WARC-Concurrent-To\":\"<urn:uuid:f4746630-a7ab-4a29-a1f9-b0d448f97fd9>\",\"WARC-IP-Address\":\"107.167.10.241\",\"WARC-Target-URI\":\"https://igeeksmagz.com/mathsolving-584\",\"WARC-Payload-Digest\":\"sha1:UVBC3LUXF4445FNOC423DXLYNLLRIW6P\",\"WARC-Block-Digest\":\"sha1:X4462UIMGVB3LBUHBGNGPKGBQSPDQF5Y\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-06/CC-MAIN-2023-06_segments_1674764500042.8_warc_CC-MAIN-20230203024018-20230203054018-00649.warc.gz\"}"} |
https://forums.atariage.com/topic/350418-sorting-looking-for-a-better-algorithm/page/2/ | [
"IGNORED\n\n# Sorting: looking for a better algorithm\n\n## Recommended Posts\n\nThis is a fascinating topic.\n\nSo I looked at my algorithm again, and I was actually mistaken as it's not really a gnome sort either because the latter goes through the entire list once the lowest swap is made in the current loop, whereas in my algorithm I jump directly to the location of the first swap for that loop iteration after the lowest swap for that iteration. Here's an example of a run for a worse case scenario:\n\n5 4 3 2 1\n\n4 5 3 2 1\n\n4 3 5 2 1\n\n3 4 5 2 1\n\n3 4 2 5 1\n\n3 2 4 5 1\n\n2 3 4 5 1\n\n2 3 4 1 5\n\n2 3 1 4 5\n\n2 1 3 4 5\n\n1 2 3 4 5\n\nThat's 10 swaps for that run. Here are the swap numbers for each n from 2 to 7. To clarify, each time a swap situation exists, then 3 additional operations occur in the algorithm, otherwise no additional operations occur. So the number of swaps can be substituted for number of ops = swaps * 3.\n\nn swaps swapsn-swapsn-1\n\n2 1 0\n\n3 3 2\n\n4 6 3\n\n5 10 4\n\n6 15 5\n\n7 21 6\n\nClearly it's a linear progression, so for the worst case scenario the algorithm has a growth of O(n) which is much better than even the combsort or the gnome sort which have a worst case scenario of O(n2)! Am I missing something here?\n\nThe number of swaps for any n here (n>2) is: ( [ i = 3 to n ]SUM ( i - 1 ) ) + 1\n\n•",
null,
"1\n##### Share on other sites\n\n99'er magazine had an article on sorting methods in TI BASIC. My older brother studied that, implemented them, but it was beyond me then.\n\nLast summer I coded Heapsort in Forth.\n\nTwo interesting properties of Heapsort: First, it doesn't need recursion. It iterates through an array, but skipping forward by powers of 2. Imagine adding up the series 1,2,4,8. How many steps will get you up to N? The answer is log2(N). (More precisely, the sum is N-1.)\n\nIt does this loop on each of N elements. To move X to its destination, it has to compare-swap X with log2(N) other elements.\n\nMaybe that helps reinforce why we say N log N complexity. Outer loop N times, inner loop log2(N) times.\n\nAnd you can see where N log N is faster than Bubble Sort (which might compare every element against each other, N*N.)\n\nSecond interesting property, Heapsort always takes N log N steps. No more, no less. I should mention that it takes two passes. Disadvantages.\n\nIn contrast, quicksort has many opportunities to exit early, avoiding a lot of compare-swap. It too is O(N log N)--but imagine that , on average, a lot of elements are left alone after one or two swaps.\n\nConsider that there are special situations where one type of sort is advantageous to your kind of data, or for what you want to get out. And the fastest sort might not be the right choice.\n\nOne situation is that you need a sorted list AND the ability to quickly insert new elements or remove some. While still keeping the list sorted.\n\nAnd not by shoving a giant block of memory one position to the right!\n\nHeapsort , after the first pass, gives you a \"heap\" which is ideal for further insertion/removal. (Guaranteed.) Sometimes that is the special property you need.\n\nBinary trees, in particular red-black trees, are another great choice for insertion/removal.\n\n•",
null,
"5\n##### Share on other sites\n\n1 hour ago, Vorticon said:\n\nThis is a fascinating topic.\n\nSo I looked at my algorithm again, and I was actually mistaken as it's not really a gnome sort either because the latter goes through the entire list once the lowest swap is made in the current loop, whereas in my algorithm I jump directly to the location of the first swap for that loop iteration after the lowest swap for that iteration. Here's an example of a run for a worse case scenario:\n\n5 4 3 2 1\n\n4 5 3 2 1\n\n4 3 5 2 1\n\n3 4 5 2 1\n\n3 4 2 5 1\n\n3 2 4 5 1\n\n2 3 4 5 1\n\n2 3 4 1 5\n\n2 3 1 4 5\n\n2 1 3 4 5\n\n1 2 3 4 5\n\nThat's 10 swaps for that run. Here are the swap numbers for each n from 2 to 7. To clarify, each time a swap situation exists, then 3 additional operations occur in the algorithm, otherwise no additional operations occur. So the number of swaps can be substituted for number of ops = swaps * 3.\n\nn swaps swapsn-swapsn-1\n\n2 1 0\n\n3 3 2\n\n4 6 3\n\n5 10 4\n\n6 15 5\n\n7 21 6\n\nClearly it's a linear progression, so for the worst case scenario the algorithm has a growth of O(n) which is much better than even the combsort or the gnome sort which have a worst case scenario of O(n2)! Am I missing something here?\n\nHow many times do you touch each element in the array?\n\nThat will determine the 'n' factor.\n\nIf your method is O(n) then you only have to scan the array once.\n\nIn other words: a 5 element array would need a 1 to 5 FOR loop run only once to complete the sort.\n\nThat's why my test example had a \"passes\" variable to count how many times I had to run through the array.\n\n•",
null,
"2\n##### Share on other sites\n\n1 minute ago, TheBF said:\n\nHow many times do you touch each element in the array?\n\nThat will determine the 'n' factor.\n\nIf your method is O(n) then you only have to scan the array once.\n\nIn other words: a 5 element array would need a 1 to 5 FOR loop run only once to complete the sort.\n\nThat's why my test example had a \"passes\" variable to count how many times I had to run through the array.\n\nAnd that's exactly what happens. I have only one loop that runs from 1 to n. Inside each iteration, it backtracks until the previous number is smaller than the current one then picks back up where it was initially in the array. Here's the code:\n\n```5000 REM ARRAY SORTING ROUTINE\n5010 FOR I=1 TO R\n5020 IF I=R THEN RETURN\n5030 POINT=I\n5080 V1=DLIST(POINT,1)::V2=DLIST(POINT+1,1)\n5090 IF V1>V2 THEN DLIST(POINT,1)=V2::DLIST(POINT+1,1)=V1 ELSE 5140\n5100 POINT=POINT-1::IF POINT>=1 THEN 5080 ELSE 5140\n5140 NEXT I```\n\n•",
null,
"2\n##### Share on other sites\n\n18 minutes ago, Vorticon said:\n\nAnd that's exactly what happens. I have only one loop that runs from 1 to n. Inside each iteration, it backtracks until the previous number is smaller than the current one then picks back up where it was initially in the array. Here's the code:\n\n```5000 REM ARRAY SORTING ROUTINE\n5010 FOR I=1 TO R\n5020 IF I=R THEN RETURN\n5030 POINT=I\n5080 V1=DLIST(POINT,1)::V2=DLIST(POINT+1,1)\n5090 IF V1>V2 THEN DLIST(POINT,1)=V2::DLIST(POINT+1,1)=V1 ELSE 5140\n5100 POINT=POINT-1::IF POINT>=1 THEN 5080 ELSE 5140\n5140 NEXT I```\n\nOk.\n\nSo I guess the only thing to do is time it for an array of size 50 and then an array of size 100 and see if it the time increase is double or what the factor actually turns out to be. You may have a new sort algorithm.",
null,
"##### Share on other sites\n\nOK so I tested 2 arrays each initialized with the worst case scenario, i.e in descending order. One array is 50 elements and the second is 100 elements.\n\nSort times:\n\n50 elements: 57 seconds\n\n100 elements: 229 seconds\n\nDefinitely not quadratic! I wonder if @TheBF can compare this with his other sorts.\n\nHere's the test code. Timing is manual.\n\n```10 CALL CLEAR::OPTION BASE 1\n20 DIM A(50),B(100)\n30 REM FILL ARRAYS\n35 PRINT \"INITIALIZING ARRAYS....\"::PRINT\n40 FOR I=1 TO 100\n60 B(I)=101-I::IF I<51 THEN A(I)=101-I\n80 NEXT I\n85 PRINT \"READY! PRESS A KEY\"::PRINT\n86 CALL KEY(0,K,S)::IF S=0 THEN 86\n90 CALL SORT(A(),50)\n95 PRINT::PRINT \"PRESS A KEY FOR NEXT ARRAY\"::PRINT\n100 CALL KEY(0,K,S)::IF S=0 THEN 100\n110 CALL SORT(B(),100)\n120 CALL KEY(0,K,S)::IF S<>0 THEN STOP\n\n1000 SUB SORT(C(),N)\n1005 PRINT \"SORTING FOR \";N;\" ELEMENTS\"\n1010 FOR I=1 TO N\n1020 IF I=N THEN 1075\n1030 P=I\n1040 V1=C(P)::V2=C(P+1)\n1050 IF V1>V2 THEN C(P)=V2::C(P+1)=V1 ELSE 1070\n1060 P=P-1::IF P>=1 THEN 1040\n1070 NEXT I\n1075 PRINT \"DONE SORTING!\"\n1080 SUBEND```\n\n•",
null,
"1\n##### Share on other sites\n\n2 hours ago, TheBF said:\n\nHow many times do you touch each element in the array?\n\nThis is the relevant count. The number of compares, regardless of whether each leads to a swap.\n\nConsider the problem as \"how many steps does it take to sort and prove that it is sorted?\" The proof requires comparing a lot more numbers along the way.\n\nAlso, O() notation is an upper bound. Some algorithms require exactly that number of steps--better algorithms in the same O() class might avoid some of the compares or swaps.\n\nGetting an element to its final spot with fewer swaps.\n\nQuicksort and Heapsort are both O(N log N) but Quicksort avoids many swaps on average. While Heapsort always does the upper limit number of swaps!\n\nWe also worry about computer implementations: which takes longer, compares or swaps? Does the computer stall when numbers are not near neighbors? (Computer waits on slow RAM.)\n\n•",
null,
"1\n##### Share on other sites\n\n57 minutes ago, Vorticon said:\n\n50 elements: 57 seconds\n\n100 elements: 229 seconds\n\nDefinitely not quadratic! I wonder if @TheBF can compare this with his other sorts.\n\n50^2/57 = 43.859\n\n100^2/229 = 43.668\n\nWhich fits 44 * x^2\n\n•",
null,
"1\n##### Share on other sites\n\n52 minutes ago, FarmerPotato said:\n\n50^2/57 = 43.859\n\n100^2/229 = 43.668\n\nWhich fits 44 * x^2\n\n1 hour ago, Vorticon said:\n\nOK so I tested 2 arrays each initialized with the worst case scenario, i.e in descending order. One array is 50 elements and the second is 100 elements.\n\nSort times:\n\n50 elements: 57 seconds\n\n100 elements: 229 seconds\n\nDefinitely not quadratic! I wonder if @TheBF can compare this with his other sorts.\n\nHere's the test code. Timing is manual.\n\n```10 CALL CLEAR::OPTION BASE 1\n20 DIM A(50),B(100)\n30 REM FILL ARRAYS\n35 PRINT \"INITIALIZING ARRAYS....\"::PRINT\n40 FOR I=1 TO 100\n60 B(I)=101-I::IF I<51 THEN A(I)=101-I\n80 NEXT I\n85 PRINT \"READY! PRESS A KEY\"::PRINT\n86 CALL KEY(0,K,S)::IF S=0 THEN 86\n90 CALL SORT(A(),50)\n95 PRINT::PRINT \"PRESS A KEY FOR NEXT ARRAY\"::PRINT\n100 CALL KEY(0,K,S)::IF S=0 THEN 100\n110 CALL SORT(B(),100)\n120 CALL KEY(0,K,S)::IF S<>0 THEN STOP\n\n1000 SUB SORT(C(),N)\n1005 PRINT \"SORTING FOR \";N;\" ELEMENTS\"\n1010 FOR I=1 TO N\n1020 IF I=N THEN 1075\n1030 P=I\n1040 V1=C(P)::V2=C(P+1)\n1050 IF V1>V2 THEN C(P)=V2::C(P+1)=V1 ELSE 1070\n1060 P=P-1::IF P>=1 THEN 1040\n1070 NEXT I\n1075 PRINT \"DONE SORTING!\"\n1080 SUBEND```\n\nI had to go out to a rehearsal, but I can try comparing this to combsort which I have in BASIC.\n\n-or- I have a sort workbench in Forth so maybe I can translate your algorithm to Forth and then do comparisons on much bigger data.\n\n•",
null,
"2\n##### Share on other sites\n\n1 hour ago, FarmerPotato said:\n\n50^2/57 = 43.859\n\n100^2/229 = 43.668\n\nWhich fits 44 * x^2\n\nBut processing time is not. In the context of sort performance, if a sort algorithm is O(n2) shouldn't processing time increase quadratically? This is not the case here.\n\n##### Share on other sites\n\nFor the comparison here is COMBSORT in BASIC using the VORTSORT chassis. (I named it)",
null,
"For the small amount of extra code COMBSORT is a lot of bang for the buck.\n\n```1 ! VORTSORT chassis with COMBSORT\n2 ! 50 elements 9.5 seconds\n3 ! 100 elements 23 seconds\n10 CALL CLEAR::OPTION BASE 1\n20 DIM A(50),B(100)\n30 REM FILL ARRAYS\n35 PRINT \"INITIALIZING ARRAYS....\"::PRINT\n40 FOR I=1 TO 100\n60 B(I)=101-I::IF I<51 THEN A(I)=101-I\n80 NEXT I\n85 PRINT \"READY! PRESS A KEY\"::PRINT\n86 CALL KEY(0,K,S)::IF S=0 THEN 86\n90 CALL COMBSORT(A(),50)\n95 PRINT::PRINT \"PRESS A KEY FOR NEXT ARRAY\"::PRINT\n100 CALL KEY(0,K,S)::IF S=0 THEN 100\n110 CALL COMBSORT(B(),100)\n120 CALL KEY(0,K,S)::IF S<>0 THEN STOP\n\n2000 SUB COMBSORT(C(),N)\n2100 PRINT \"SORTING FOR \";N;\" ELEMENTS\"\n2420 PASSES=0\n2424 GAP=N\n2440 SORTED=1\n2442 GAP=INT(GAP/1.3)\n2450 FOR I=1 TO N-GAP\n2460 IF C(I)<C(I+GAP) THEN 2530\n2470 rem swap the array items\n2480 TEMP=C(I)\n2490 C(I)=C(I+GAP)\n2500 C(I+GAP)=TEMP\n2520 SORTED=0\n2530 NEXT I\n2540 PASSES=PASSES+1\n2550 REM test if sort is finished\n2570 IF GAP=1 THEN 2600\n2580 GOTO 2440\n2600 SUBEND\n```\n\n•",
null,
"1\n##### Share on other sites\n\nWow. The difference is impressive... So much for Vortsort",
null,
"I did track the number of comparisons instead for just swaps for arrays 50,100,150 and 200 elements and I got the following:\n\nClearly not linear. And as @FarmerPotato noted, n2/#comparisons is a constant = 2. So yeah, this sort is an O(n2) type under the worst case scenario.\n\nOh well, I guess fame will have to wait... 😝\n\n•",
null,
"3\n•",
null,
"2\n##### Share on other sites\n\n19 hours ago, SteveB said:\n\n...still some Quicksort implementation totally freak out when handed an already sorted list ... The language for the implementation should support recursions, I wouldn't do it in TI BASIC. When implementing it in assembly you need to implement the recursion manually. A whole new science is sorting datasets larger than your RAM, which has been a big issue in the early mainframe world... tape-to-tape sorting.\n\nThe Quicksort I wrote once, when I learned about the algorithm, doesn't \"freak out\", but it does run for a longer time when the list is already sorted.\nYou can \"unwrap\" the recursion even when writing it in e.g. Pascal. They claimed where the article was described that it would be more efficient. It may of course depend on how recursion is implemented in the language.\n\nSince I managed to sort a thousand integers in about half a second on the TI 99/4A, I was happy. Due to the limited memory capacity of such a small computer there's normally not the need to sort vast amounts of numbers either.\n\n•",
null,
"3\n##### Share on other sites\n\n7 hours ago, Vorticon said:\n\nOh well, I guess fame will have to wait... 😝\n\nThere is a reason that there is not \"THE ONE[tm]\" sorting algorithm. It depends very much on data, hardware, programming language ... you just need to find the niche where VORTSORT outperforms the others.\n\nThe O() logic also looks at infinity ... most data we are dealing with is finite. A simple O(N^3) may outperform a O(n*log(n)) on a small dataset on a real machine. And coding time is also important 🙃\n\n•",
null,
"4\n##### Share on other sites\n\nSince I managed to sort a thousand integers in about half a second on the TI 99/4A, I was happy. Due to the limited memory capacity of such a small computer there's normally not the need to sort vast amounts of numbers either.\n\nWould you happen to have the code for it? I assume this was done using UCSD Pascal which supports recursion.\n\n##### Share on other sites\n\n16 hours ago, FarmerPotato said:\n\nTwo books that I learned from are Algorithms, by Sedgwick, and Numerical Recipes in C.\n\nSedgwick comes in Pascal, C and other flavors.\n\nNumerical Recipes covers just enough sorting, and is a reference on many other mathematical computing topics.\n\nI have used many references for this and other topics of scientific computing (more for data analysis than sorting) over the years—including Numerical Recipes: The Art of Scientific Computing by Press, Teukolsky, Vetterling, and Flannery and various volumes of The Art of Computer Programming by D. E. Knuth, but probably none more than Numerical Recipes.\n\n...lee\n\n•",
null,
"4\n##### Share on other sites\n\n•",
null,
"5\n##### Share on other sites\n\nOn 4/18/2023 at 4:22 AM, SteveB said:\n\nAnd coding time is also important\n\nIndeed. Vortsort can be compressed into just 4 lines of code in XB and performance is likely comparable to Insertion or Gnome sort or perhaps even a little better.\n\n```1000 SUB VORTSORT(C(),N)\n1010 FOR I=1 TO N-1::P=I\n1040 V1=C(P)::V2=C(P+1)::IF V1<V2 THEN 1070 ELSE C(P)=V2::C(P+1)=V1::P=P-1::IF P>=1 THEN 1040\n1070 NEXT I::SUBEND```\n\nI'm keeping it for future use.\n\n•",
null,
"4\n##### Share on other sites\n\n<pedant>\n\nI think the ELSE 1070 at the end of line 1040 can be omitted - it's redundant.\n\n</pedant>",
null,
"•",
null,
"4\n##### Share on other sites\n\nThe Quicksort I wrote once, when I learned about the algorithm, doesn't \"freak out\", but it does run for a longer time when the list is already sorted.\nYou can \"unwrap\" the recursion even when writing it in e.g. Pascal. They claimed where the article was described that it would be more efficient. It may of course depend on how recursion is implemented in the language.\n\nSince I managed to sort a thousand integers in about half a second on the TI 99/4A, I was happy. Due to the limited memory capacity of such a small computer there's normally not the need to sort vast amounts of numbers either.\n\nIt would be very interesting to see how a non-recursive Quicksort performs in TI BASIC. The amazing speed of the sort would be offset by the extra BASIC instructions which are very slow.\n\nBelow some size of the data there would be no benefit versus a simpler algorithm I suspect.\n\nI think I have textbook with the non-recursive version in Pascal. I might take a run at it.\n\n•",
null,
"2\n##### Share on other sites\n\n18 minutes ago, Willsy said:\n\n<pedant>\n\nI think the ELSE 1070 at the end of line 1040 can be omitted - it's redundant.\n\n</pedant>",
null,
"Yup. Forgot to remove it when I reformatted the code.\n\n•",
null,
"3\n##### Share on other sites\n\nPosted (edited)\n3 hours ago, Vorticon said:\n\nWould you happen to have the code for it? I assume this was done using UCSD Pascal which supports recursion.\n\nHere it is. The assembly version, that is. I did start with a Pascal version, but don't have that handy now.\n\nQuicksort\nIt's still kind of recursive in prinicple, but not with a full scale recursive routine call.\n\nBy mistake I wrote somewhere that it uses bubblesort to finish up, but it doesn't. It's insertionsort I use to finalize short lists.\n\nThe program is based on a program written in Algol from the beginning.\n\n•",
null,
"1\n•",
null,
"1\n##### Share on other sites\n\n7 hours ago, Vorticon said:\n\n```1000 SUB VORTSORT(C(),N)\n1010 FOR I=1 TO N::IF N=I THEN SUBEXIT ELSE P=I\n1040 V1=C(P)::V2=C(P+1)::IF V1<V2 THEN 1070 ELSE C(P)=V2::C(P+1)=V1::P=P-1::IF P>=1 THEN 1040 ELSE 1070\n1070 NEXT I::SUBEND```\n\nI'm keeping it for future use.\n\nAgree this is valuable because it's so short.\n\nyou can eliminate IF I=N\n\nby saying FOR I=1 TO N-1\n\n•",
null,
"1\n##### Share on other sites\n\nHere it is. The assembly version, that is. I did start with a Pascal version, but don't have that handy now.\n\nQuicksort\nIt's still kind of recursive in prinicple, but not with a full scale recursive routine call.\n\nBy mistake I wrote somewhere that it uses bubblesort to finish up, but it doesn't. It's insertionsort I use to finalize short lists.\n\nThe program is based on a program written in Algol from the beginning.\n\nAnd here is a version that assembles with the default TI Assembler. You will have to un-comment the BLWP line and the two below.\n\nReadme from my time working on it:\n\nThis code is from a demo in UCSD Pascal by @apperson850 on artiage.com.\n\nThe original has been modified to assemble with the stock TI-99 ASSEMBLER. The\nDATA in the Forth's memory, taking the address and size of an array from Forth's\ndata stack and jumping into QUICKSORT.\n\n1000 items can be sorted in under 2 seconds on a stock console.\n\nSpoiler\n```* TITL \"QUICKSORT FOR INTEGERS\"\n\n* Procedure sorting integers in ascending order\n* Called from Pascal host by QSORT(A,N)*\n* Declared as PROCEDURE QSORT(VAR A:VECTOR* N:INTEGER)* EXTERNAL*\n* Vector should be an array [..] of integer*\n\n* Author: @APERSON850 on Atariage.com\n\n* Modified for TI Assembler, to be called from Camel99 Forth\n* 2022 Brian Fox\n\n*--------------\n* Workspace registers for subroutine at START\n*\n* R0 Array base pointer\n* R1 Array end pointer\n* R2 L\n* R3 R\n* R4 I\n* R5 J\n* R6 KEY\n* R7 Temporary\n* R8 Temporary\n* R9 Subfile stack pointer\n* R10 Main stackpointer\n* R11 Pascal return address (P-system WS)\n* R12 Not used\n* R13 Calling program's Workspace Pointer\n* R14 Calling program's Program Counter\n* R15 Calling program's Status Register\n*-----------------\n\n* The actual vector in the Pascal-program could be indexed [1..n]\n* This routine assumes only that n indicates the number of elements, not the\n* last array index.\n\nDEF QSORT\n\nLIMIT EQU 16 *Quick- or Insertionsort limit\n\n* * Don't need this for Forth **\n* BLWP @QSORT\n* AI R10,4 *Simulate pop of two words\n* B *R11 *Back to Pascal host\n\nQSORT DATA SORTWS,START *Transfer vector for Quicksort\n\nSTART MOV @12(R13),R10 *Get stackpointer (R6) from Forth's WP->R10\nLI R9,ENDSTK *SUBFILE STACKPOINTER\nMOV *R10+,R1 * POP PARAMETER N\nMOV *R10+,R0 * POP ARRAY POINTER\nDEC R1\nSLA R1,1\nA R0,R1 *CALCULATE ARRAY ENDPOINT\n\nMOV R0,R2 *L:=1\nMOV R1,R3 *R:=N\nMOV R1,R7\nS R0,R7\nCI R7,LIMIT\nJLE INSERT *FIGURE OUT IF QUICKSORT IS NEEDED\n\nMNLOOP MOV R2,R7\nSRL R7,1\nMOV R3,R8\nSRL R8,1\nA R8,R7\nANDI R7,>FFFE *R7:=INT((L+R)/2)\nMOV *R7,R8\nMOV @2(R2),*R7\nMOV R8,@2(R2) *A[(L+R)/2]:=:A[L+1]\n\nC @2(R2),*R3\nJLT NOSWP1\nMOV @2(R2),R8\nMOV *R3,@2(R2)\nMOV R8,*R3 *A[L+1]:=:A[R]\n\nNOSWP1 C *R2,*R3\nJLT NOSWP2\nMOV *R2,R8\nMOV *R3,*R2\nMOV R8,*R3 *A[L]:=:A[R]\n\nNOSWP2 C @2(R2),*R2\nJLT NOSWP3\nMOV @2(R2),R8\nMOV *R2,@2(R2)\nMOV R8,*R2 *A[L+1]:=:A[L]\n\nNOSWP3 MOV R2,R4\nINCT R4 *I:=L+1\nMOV R3,R5 *J:=R\nMOV *R2,R6 *KEY:=A[L]\nJMP INCLOP\n\nINRLOP MOV *R4,R8 *LOOP UNWRAPPING\nMOV *R5,*R4\nMOV R8,*R5 *A[I]:=:A[J]\n\nINCLOP INCT R4 *I:=I+1\nC *R4,R6\nJLT INCLOP *A[I]<KEY\n\nDECLOP DECT R5 *J:=J-1\nC *R5,R6\nJGT DECLOP *A[J]>KEY\n\nC R4,R5\nJLE INRLOP *IF I<=J THEN CONTINUE\n\nOUT MOV *R2,R8\nMOV *R5,*R2\nMOV R8,*R5 *A[L]:=:A[J]\n\nDEL1 MOV R5,R7 *Quicksort subfiles?\nS R2,R7 *R7:=J-L\nMOV R3,R8\nS R4,R8\nINCT R8 *R8:=R-I+1\nCI R7,LIMIT\nJH DEL2\nCI R8,LIMIT\nJH DEL2\n\nCI R9,ENDSTK *LVL=0?\nJEQ INSERT *No more Quicksorting at all?\n\nMOV *R9+,R2 *POP L\nMOV *R9+,R3 *POP R\nJMP MNLOOP\n\nDEL2 C R7,R8 *Determine what is small and large subfile\nJL ELSE2\n\nMOV R2,@LSFL\nMOV R5,@LSFR\nDECT @LSFR\nMOV R4,@SSFL\nMOV R3,@SSFR\nJMP DEL3\n\nELSE2 MOV R4,@LSFL\nMOV R3,@LSFR\nMOV R2,@SSFL\nMOV R5,@SSFR\nDECT @SSFR\n\nDEL3 CI R7,LIMIT *Is small subfile big enough to be sorted by\nJLE THEN3 *Quicksort?\nCI R8,LIMIT\nJH ELSE3\n\nTHEN3 MOV @LSFL,R2 *Don't Quicksort small subfile, only large\nMOV @LSFR,R3\nJMP MNLOOP\n\nELSE3 DECT R9 *Stack large subfile\nMOV @LSFR,*R9 *PUSH R\nDECT R9\nMOV @LSFL,*R9 *PUSH L\nMOV @SSFL,R2 *Sort small subfile\nMOV @SSFR,R3\nJMP MNLOOP\n\n*\n* Insertion Sort finishing up\n*\nINSERT MOV R1,R4\nDECT R4 *I:=N-1\nC R4,R0\nJL LEAVE *Check if any looping at al\n\nFORI C @2(R4),*R4\nJGT NEXTI *If next is greater than this, it's OK\n\nMOV *R4,R6 *KEY:=A[I]\nMOV R4,R5\nINCT R5 *J:=I+1\n\nWHILE MOV *R5,@-2(R5) *A[J-1]:=A[J]\nINCT R5 *J:=J+1\nC R5,R1\nJH ENDWHL *J>N?\nC *R5,R6 *A[J]<KEY?\nJLT WHILE\nENDWHL MOV R6,@-2(R5) *A[J-1]:=KEY\nNEXTI DECT R4\nC R4,R0 *Check if passed array base point\nJHE FORI\n\nLEAVE RTWP * Return Forth workspace\n* AI R6,4 * remove parameters from Forth stack\nB @R10 * Branch to Forth interpreter\n\n*--------------\n* DATA AREA\n\nSORTWS BSS >20 *Workspace for sorting routine\nSUBSTK BSS >40 *Internal subfile stack\nENDSTK EQU SUBSTK+>40 *End of that stack\n\n* variable used by quicksort\nLSFL DATA 0 *Large SubFile Left pointer\nLSFR DATA 0 *Large SubFile Right pointer\nSSFL DATA 0 *Small SubFile Left pointer\nSSFR DATA 0 *Small SubFile Right pointer\n\nEND\n```\n\n•",
null,
"1\n##### Share on other sites\n\n1 hour ago, FarmerPotato said:\n\nAgree this is valuable because it's so short.\n\nyou can eliminate IF I=N\n\nby saying FOR I=1 TO N-1\n\nYes! Every little trim helps.\n\n•",
null,
"1\n\n## Join the conversation\n\nYou can post now and register later. If you have an account, sign in now to post with your account.\nNote: Your post will require moderator approval before it will be visible.",
null,
"× Pasted as rich text. Paste as plain text instead\n\nOnly 75 emoji are allowed."
] | [
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/emoticons/atariage_icon_smile.gif",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/emoticons/atariage_icon_smile.gif",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/emoticons/atariage_icon_lol.gif",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_haha.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/emoticons/atariage_icon_winking.gif",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/emoticons/atariage_icon_winking.gif",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_thanks.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/reactions/react_like.png",
null,
"https://content.invisioncic.com/r322239/set_resources_6/84c1e40ea0e759e3f1505eb1788ddf3c_default_photo.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.90156996,"math_prob":0.825864,"size":1545,"snap":"2023-14-2023-23","text_gpt3_token_len":469,"char_repetition_ratio":0.11161584,"word_repetition_ratio":0.05105105,"special_character_ratio":0.30938512,"punctuation_ratio":0.06741573,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9746126,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,4,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-06-05T17:03:50Z\",\"WARC-Record-ID\":\"<urn:uuid:5222e8bc-c36a-4dfd-a9fa-1f824f684bcc>\",\"Content-Length\":\"449330\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:b80b8f65-067b-4040-a60f-d71500b38cfe>\",\"WARC-Concurrent-To\":\"<urn:uuid:0829e892-89d9-434a-b6d8-79e89e9f93ef>\",\"WARC-IP-Address\":\"13.32.208.21\",\"WARC-Target-URI\":\"https://forums.atariage.com/topic/350418-sorting-looking-for-a-better-algorithm/page/2/\",\"WARC-Payload-Digest\":\"sha1:63MBQPRBFLUNLVNMH5FHOKPUCOAMRKUH\",\"WARC-Block-Digest\":\"sha1:BDVKGQETIVWQS6G2CJMZWY3ZARHGZ4HC\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-23/CC-MAIN-2023-23_segments_1685224652149.61_warc_CC-MAIN-20230605153700-20230605183700-00621.warc.gz\"}"} |
https://whatmaster.com/what-is-a-geometric-figure/ | [
"CONCEPTS\n\n# What is a geometric figure?\n\nWe explain what geometric figures are and the ways in which they can be classified. In addition, some examples of these figures.\n\n1. ### What is a geometric figure?\n\nA geometric figure is the visual and functional representation of a non-empty and closed set of points in a geometric plane. That is, figures that delimit flat surfaces through a set of lines (sides) that join their points in a specific way. Depending on the order and number of these lines we will talk about one figure or another.\n\nGeometric figures are the work of geometry , a branch of mathematics that studies representational planes and the relationships between the forms we can imagine in them. These are, therefore, abstract objects, according to which our perspective and our way of spatially understanding the universe around us are determined.\n\nYou can classify the geometric figures according to their shape and number of sides, but also based on the number of dimensions represented, being able to talk about:\n\n• Dimensional figures (0 dimensions) . It basically refers to the point.\n• Linear figures (1 dimension) . These are the lines and the curves, that is, lines with some orientation and determined path.\n• Flat figures (2 dimensions) . Polygons, planes and surfaces, which lack depth but have a measurable length and width.\n• Volumetric figures (3 dimensions) . Three-dimensional figures add depth and perspective to the matter, and can be considered geometric bodies, such as polyhedra and solids in revolution.\n• N-dimensional figures (n-dimensions) . These are theoretical abstractions endowed with n appreciable dimensions.\n\nWe should note that to define the geometric figures , abstractions such as the point, the line and the plane are often used , which are in turn considered geometry figures.\n\n1. ### Examples of geometric figures",
null,
"Squares necessarily have four equal sides.\n\nSome examples of geometric figures are:\n\n• Triangles . Flat figures characterized by having three sides, that is, three lines in contact forming three vertices. Depending on the type of angle they build, they can be equilateral triangles (three equal sides), isosceles (two equal and one different) or scalenes (all unequal).\n• Squares . These flat figures are always identical in proportion but not in size, having four sides necessarily of the same length. Its four angles will then be right angles (90 °).\n• Rhombus s . Similar to the square, they have four identical sides in contact, but none constitute right angles, but acute and two obtuse.\n• Circumferences . It is a flat and closed curve on itself, in which any chosen point of the line is at the same identical distance from the center (or axis). It could be called a perfect circle.\n• Ellipses . Closed curves similar to the circumference, but with two axes or centers instead of one, generating a flattened or elongated spheroid, depending on whether it revolves around its minor or major axis, respectively.\n• Pyramids . Three-dimensional geometric bodies formed by a quadrangular base and four isosceles triangles that act as sides."
] | [
null,
"https://whatmaster.com/wp-content/uploads/2020/02/03-193.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.92865074,"math_prob":0.9822912,"size":3035,"snap":"2021-21-2021-25","text_gpt3_token_len":618,"char_repetition_ratio":0.14879578,"word_repetition_ratio":0.004008016,"special_character_ratio":0.20296541,"punctuation_ratio":0.122486286,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9962667,"pos_list":[0,1,2],"im_url_duplicate_count":[null,1,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-06-12T21:19:15Z\",\"WARC-Record-ID\":\"<urn:uuid:89cfc51a-5ff0-4398-a601-617a56a97114>\",\"Content-Length\":\"131478\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:9fbbb2d1-a94c-44c4-9e85-a6f4ae4ddbc2>\",\"WARC-Concurrent-To\":\"<urn:uuid:5885d43f-8e3b-41bb-8e45-f4f92d66a72d>\",\"WARC-IP-Address\":\"74.208.236.160\",\"WARC-Target-URI\":\"https://whatmaster.com/what-is-a-geometric-figure/\",\"WARC-Payload-Digest\":\"sha1:DC2QR5ACG3IW2NUUWRKUL6TW25K7RUEQ\",\"WARC-Block-Digest\":\"sha1:JB6PNNDB66LQLEDYDM4GBOJWVKMCJUNI\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-25/CC-MAIN-2021-25_segments_1623487586390.4_warc_CC-MAIN-20210612193058-20210612223058-00083.warc.gz\"}"} |
https://www.turito.com/ask-a-doubt/Mathematics-lin-creates-a-pattern-using-the-white-and-black-tiles-the-number-of-white-tiles-present-in-the-next-sha-qe11e76 | [
"Mathematics\nEasy\n\nQuestion\n\n# Lin creates a pattern using the white and black tiles.",
null,
"The number of white tiles present in the next shape of Lin’s pattern is _____.\n\n## 15 16 20 25",
null,
"Hint:\n\n## The correct answer is: 16\n\n### The number of tiles is increasing with the number of shape. The rule used to create the shape is the number of tiles is given by a square. And the number is increasing by 1.The first shape requires 12 = 1 white tiles.The second shape requires 22 = 4 white tiles.The third shape requires 32 = 9 white tiles.So, the next figure will be square of next number that is 4.Therefore, 4th shape requires 42 = 16 white tiles.\n\nWe have to be careful about the sequence of the shape. We have to increase the number of tiles in proper order.\n\n### Related Questions to study",
null,
"",
null,
"#### With Turito Foundation.",
null,
"#### Get an Expert Advice From Turito.",
null,
"",
null,
""
] | [
null,
"https://mycourses.turito.com/tokenpluginfile.php/c161933dbfaab094c54655ab71e9b8f0/1/question/questiontext/888095/1/1207599/Picture65.png",
null,
"https://www.turito.com/images/idea_green.svg",
null,
"https://www.turito.com/_next/image",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9079809,"math_prob":0.95818377,"size":1042,"snap":"2023-40-2023-50","text_gpt3_token_len":257,"char_repetition_ratio":0.20905587,"word_repetition_ratio":0.029850746,"special_character_ratio":0.2581574,"punctuation_ratio":0.09954751,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9653665,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14],"im_url_duplicate_count":[null,1,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-12-04T13:42:58Z\",\"WARC-Record-ID\":\"<urn:uuid:481f8b91-17c3-4f9c-af19-180d59037417>\",\"Content-Length\":\"74648\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:51ea5497-fba3-4482-b8b7-8193e05e61c3>\",\"WARC-Concurrent-To\":\"<urn:uuid:da5d41ae-0f64-4546-aadf-59c48497e52c>\",\"WARC-IP-Address\":\"3.108.140.208\",\"WARC-Target-URI\":\"https://www.turito.com/ask-a-doubt/Mathematics-lin-creates-a-pattern-using-the-white-and-black-tiles-the-number-of-white-tiles-present-in-the-next-sha-qe11e76\",\"WARC-Payload-Digest\":\"sha1:XYTWDTMO7J3YDT3PXK5Y62TE4DDEK7CZ\",\"WARC-Block-Digest\":\"sha1:LTL7AMM3YZ4KDXCXVTCWNI4SW4QZJYJV\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-50/CC-MAIN-2023-50_segments_1700679100529.8_warc_CC-MAIN-20231204115419-20231204145419-00293.warc.gz\"}"} |
https://coding-gym.org/tags/subarray/ | [
"## eTonno influencers accuracy\n\nSolutions A brute-force solution (considering the set of all possible transactions) is clearly too expensive. To grasp the optimal solution, consider this example: 1 1, 7, 2, 3, 6, 7, 6, 7 To obtain the maximum profit, the - possibly - most intuitive set of transactions is: 1 (buy=1, sell=7) + (buy=2, sell=7) + (buy=6, sell=7) = 6 + 5 + 1 = 12 Look at the increasing sub-series 2, 3, 6, 7. [Read More]"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.7413337,"math_prob":0.9823136,"size":431,"snap":"2022-40-2023-06","text_gpt3_token_len":144,"char_repetition_ratio":0.12412178,"word_repetition_ratio":0.0,"special_character_ratio":0.34106728,"punctuation_ratio":0.19587629,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9847828,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-10-05T21:35:53Z\",\"WARC-Record-ID\":\"<urn:uuid:1e514eae-0bf8-4d4b-a3e3-3ce0c134b81c>\",\"Content-Length\":\"8702\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:ff10defc-c4c4-4b55-9b1f-a41abc7c8d16>\",\"WARC-Concurrent-To\":\"<urn:uuid:f0576060-bf53-44b6-bb2d-0b548d19c089>\",\"WARC-IP-Address\":\"35.185.44.232\",\"WARC-Target-URI\":\"https://coding-gym.org/tags/subarray/\",\"WARC-Payload-Digest\":\"sha1:5MJOTZCQT7RCAYVOUOFA5PZMVYYT433A\",\"WARC-Block-Digest\":\"sha1:J7HZZRU5YBCSCFJKO4IDNPW76L45FTG3\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-40/CC-MAIN-2022-40_segments_1664030337668.62_warc_CC-MAIN-20221005203530-20221005233530-00337.warc.gz\"}"} |
https://www.baeldung.com/cs/graphs-max-number-of-edges | [
"## 1. Overview\n\nIn this tutorial, we’ll discuss how to calculate the maximum number of edges in a directed graph.\n\n## 2. A Simple Definition of Directed Graph\n\nIn graph theory, graphs can be categorized generally as a directed or an undirected graph. In this section, we’ll focus our discussion on a directed graph.\n\nLet’s start with a simple definition. A graph",
null,
"is a directed graph if all the edges in the graph",
null,
"have direction. The vertices and edges in",
null,
"should be connected, and all the edges are directed from one specific vertex to another.\n\nThe main difference between a directed and an undirected graph is reachability. Let’s explain this statement with an example:",
null,
"We’ve taken a graph",
null,
". The vertex set",
null,
"contains five vertices:",
null,
". The edge set",
null,
"of",
null,
"contains six edges:",
null,
".\n\nNow as we discussed, in a directed graph all the edges have a specific direction. For example, edge",
null,
"can only go from vertex",
null,
"to",
null,
". Unlike an undirected graph, now we can’t reach the vertex",
null,
"from",
null,
"via the edge",
null,
".\n\nHence in a directed graph, reachability is limited and a user can specify the directions of the edges as per the requirement.\n\n## 3. When a Directed Graph Contains Maximum Edges?\n\nIn this section, we’ll discuss some conditions that a directed graph needs to hold in order to contain the maximum number of edges.\n\nFirstly, there should be at most one edge from a specific vertex to another vertex. This ensures all the vertices are connected and hence the graph contains the maximum number of edges. In short, a directed graph needs to be a complete graph in order to contain the maximum number of edges.\n\nIn graph theory, there are many variants of a directed graph. To make it simple, we’re considering a standard directed graph. So in our directed graph, we’ll not consider any self-loops or parallel edges.\n\n## 4. A General Formula for Maximum Edges Calculation\n\nIn this section, we’ll present a general formula to calculate the maximum number of edges that a directed graph can contain.\n\nLet’s assume an undirected graph with",
null,
"vertices. Further, we’re also assuming that the graph has a maximum number of edges. In such a case, from the starting vertex, we can draw",
null,
"edges in the graph. Continuing this way, from the next vertex we can draw",
null,
"edges.\n\nHence the maximum number of edges in an undirected graph is:",
null,
"Now, in an undirected graph, all the edges are bidirectional. We can convert an undirected graph into a directed graph by replacing each edge with two directed edges. Hence the revised formula for the maximum number of edges in a directed graph:",
null,
"## 5. An Example\n\nIn this section, we’ll take some directed graph and calculate the maximum number of edges according to the formula we derived:",
null,
"Now, we already discussed some conditions and assumptions for a directed graph such that it contains the maximum number of edges. Let’s verify first whether this graph contains the maximum number of edges or not.\n\nFirst, let’s check if it is a complete directed graph or not. In a complete directed graph, all the vertices are reachable from one another. In the above graph, we can see all the vertices are reachable from one another.\n\nSecondly, in our directed graph, there shouldn’t be any parallel edges or self-loop. Our example directed graph satisfies this condition too. Now let’s proceed with the edge calculation. Note that each edge here is bidirectional. Hence, each edge is counted as two independent directed edges.\n\nThe maximum number of edges =",
null,
"and the above graph has all the edges it can contain.\n\nLet’s take another graph:",
null,
"Does this graph contain the maximum number of edges? Let’s check.\n\nTo verify this, we need to check if all the vertices can reach from one another. If we take a deep loop in the graph, we can see a lot of vertices can’t reach each other via a single edge.\n\nTherefore, we can conclude that the given directed graph doesn’t contain the maximum number of edges. According to our formula, this graph has the capacity to contain maximum of",
null,
"edges. But the graph has 16 edges in this example.\n\n## 6. Conclusion\n\nIn this tutorial, we’ve discussed how to calculate the maximum number of edges in a directed graph.\n\nWe’ve presented a general formula for calculating the maximum number of edges in a directed graph and verified our formula with the help of a couple of examples."
] | [
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-eaa54ad1d5903544229dbbebdf92afbd_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-1e40206e25474f738eeb7ca968031abf_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-1e40206e25474f738eeb7ca968031abf_l3.svg",
null,
"https://www.baeldung.com/wp-content/uploads/sites/4/2020/06/graph-1.png",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-e3192da0128dfabe5fce82166bdc373c_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-54e215a7a583b4f357a5a627420bcf2f_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-505498cd4401f369536779b85c9f4206_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-638a7387bd72763290cc777a9b509c38_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-e3192da0128dfabe5fce82166bdc373c_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-3ffabe3c897ee301a3d3ad0b12041d64_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-ac91793e30799352150fdae8a6ae5d48_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-c13da9eae23428ebdd0fed62ec5a2124_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-93741ff3d67e852e96df8314f03552f6_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-c13da9eae23428ebdd0fed62ec5a2124_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-93741ff3d67e852e96df8314f03552f6_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-ac91793e30799352150fdae8a6ae5d48_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-7354bae77b50b7d1faed3e8ea7a3511a_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-b8d591aa3d3a6700d7bc61014596c9fb_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-91c3bf97740f19afb5e1c465cfc5510d_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-03fd9865d9c031490aea97d5172a89da_l3.svg",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-833956ebdd46ec4302a307b272da5b79_l3.svg",
null,
"https://www.baeldung.com/wp-content/uploads/sites/4/2020/06/graph-2.png",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-be79e9c203cad64e02e64c142b220f53_l3.svg",
null,
"https://www.baeldung.com/wp-content/uploads/sites/4/2020/06/Capture.png",
null,
"https://www.baeldung.com/wp-content/ql-cache/quicklatex.com-76c2f9fc5a2660966460ba939a42d02c_l3.svg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9472039,"math_prob":0.983411,"size":4249,"snap":"2023-40-2023-50","text_gpt3_token_len":881,"char_repetition_ratio":0.23674911,"word_repetition_ratio":0.08819538,"special_character_ratio":0.20475405,"punctuation_ratio":0.11214953,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9996699,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50],"im_url_duplicate_count":[null,null,null,null,null,null,null,4,null,null,null,null,null,2,null,null,null,null,null,2,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,6,null,2,null,2,null,2,null,4,null,2,null,4,null,2,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-10-02T18:13:10Z\",\"WARC-Record-ID\":\"<urn:uuid:e6b5b6e7-d5ea-433b-af73-3b18b697145a>\",\"Content-Length\":\"73142\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:30229368-bd6b-44f4-b69c-3e3fa0ce746a>\",\"WARC-Concurrent-To\":\"<urn:uuid:006269ea-de9e-4b24-81b9-a190dea3bdc6>\",\"WARC-IP-Address\":\"172.66.40.248\",\"WARC-Target-URI\":\"https://www.baeldung.com/cs/graphs-max-number-of-edges\",\"WARC-Payload-Digest\":\"sha1:7GMKAPHTNUVWE3CUDRBBKBHWTI7PH6S7\",\"WARC-Block-Digest\":\"sha1:APVAM7ZBDZHDJQU5OPXKHDH4DTFOYKEE\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-40/CC-MAIN-2023-40_segments_1695233511002.91_warc_CC-MAIN-20231002164819-20231002194819-00773.warc.gz\"}"} |
https://quantitysystem.wordpress.com/2010/04/15/work-and-torque-solution/ | [
"I am really sorry\n\nI didn’t notice that I haven’t posted how did I solve the dilemma of Torque and Work Problem\n\nhowever the solution was there in my discussion of quantity System http://quantitysystem.codeplex.com/Thread/View.aspx?ThreadId=23672\n\nand also on this post of my personal blog http://blog.lostparticles.net/?p=28\n\n# Problem Core: Length\n\nSimply I defined TWO Length Types\n\n## Normal Length (NL)\n\nThis is the normal length that we refer to it in our daily life\n\nThis is the radius length that have an origin point in center of circle\n\n## Quantities\n\nWork: Force * Normal Length\n\nAngle: Normal Length / Radial Length\n\nIn quantity system I made the L dimension as NL+RL\n\nCAN YOU SEE ANGLE\n\nI made it explicitly a quantity that is NOT dimensionless\n\nand THIS SOLVED ALL my problems of this Problem\n\nI won’t argue much let us test 🙂\n\nTorque * Angle = Work\n\nF*RL * (NL/RL) = F * NL <== see what I mean\n\nTorque * Angular Speed = Power\n\nF*RL * (NL/RL*T) = F*NL/T <== where T is the time.\n\nso you may wonder about Angle and Solid Angle\n\nin SI they are all dimensionless but in Quantity System YOU CAN’T consider them like this\n\n(By the way I’ve break the checking for these two quantities to be summable with dimensionless numbers – just to keep the fundamentals as it is although I am not convinced and I may remove it in future but damn it I need support from any physics guy)\n\nANGLE : NL/RL\n\nSolid Angle: NL^2/RL^2 because its area over area\n\nFrequency = 1/T\n\nAngular Velocity = (NL/RL)/T\n\ndo you remember the conversion between RPM to frequency\n\nRPM (Revolution Per Minute) is a Angle / Time\n\nlets test the law\n\nOmega = 2*pi*frequency\n\npi: radian value which is NL/RL\n\nOmega = (NL/RL) * 1/T = (NL/RL)/T which angular velocity\n\n# Discoveries\n\n## PI value\n\nPI is ratio of any circle‘s circumference to its diameter WHICH MEANS (NL/RL)\n\nthis is the same value as the ratio of a circle’s area to the square of its radius WHICH MEANS (NL^2/RL^2)\n\nwhich corresponds to radian unit and stradian unit for angle and solid angle quantities.\n\n## Reynolds Number\n\nI am not holding back ( Reynolds number is a dimensionless number that measure inertial forces to viscous forces)\n\nWHY we always differentiating between Flow in Pipes and Flow on Flat plate\n\nlet’s see with normal length in quantity system\n\nQs> rho = 3[Density]\nDensity: 3 <kg/m^3>\nQs> v=0.5<m/s>\nSpeed: 0.5 <m/s>\nQs> l=4<m>\nLength: 4 m\nQs> mue = 2<Pa.s>\nViscosity: 2 <Pa.s>\nQs> rho*v*l/mue\nDimensionlessQuantity: 3 <kg/m.s^2.Pa>\n\nit shows it is a dimensionless quantity\n\nok let us force my theory about flow in pipes\n\nthe pipe have a diameter and Reynolds number is calculated by rho*v*DIAMETER/viscosity\n\nso let me add d as a diameter and solve again\n\nQs> d=0.5<m!>\n\nQs> rho*v*d/mue\n\nDerivedQuantity: 0.375 <kg/m.s^2.Pa>\n\nNOTE: Adding ‘!’ after the length unit will mark the quantity as Radial Length quantity.\n\nERROR it shouldn’t be DerivedQuantity at all it should be Dimensionlesss\n\nso there is another term that should be fixed. Do you know which term ???\n\nlets try the velocity with vr=0.5<m!/s>\n\nQs> vr=0.5<m!/s>\n\nDerivedQuantity: 0.5 <m/s>\n\nQs> rho*vr*d/mue\n\nDerivedQuantity: 0.375 <kg/m.s^2.Pa>\n\nALSO ERROR\n\nok let us try the density\n\nQs> rhor = 3<kg/m!^3>\n\nDerivedQuantity: 3 <kg/m^3>\n\nQs> rhor*v*d/mue\n\nSolidAngle: 0.375 <kg/m.s^2.Pa>\n\nCAN YOU SEE THE SOLID ANGLE Quantity\n\ndo you remember the above argue about Solid Angle is dimensionless number\n\ncan I pretend now that reynolds number for pipes is CORRECT ???\n\nthe new density which is kg/m!^3\n\nThis is driving me nuts\n\n## Pump Affinity Laws\n\nAlso pump equations led to the same SolidAngle Quantity not DimensionLess one\n\n# Epilogue\n\nI’ve said what I’ve discovered till now about this problem I hope that may be someday someone explain to me or convince me that Angle is really a Dimensionless number after all of this and that my assumption about Torque and Work is Wrong.\n\nFrom → Uncategorized\n\nOne Comment"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8694817,"math_prob":0.95537186,"size":3733,"snap":"2020-45-2020-50","text_gpt3_token_len":1002,"char_repetition_ratio":0.11558058,"word_repetition_ratio":0.0,"special_character_ratio":0.23921779,"punctuation_ratio":0.070866145,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99598795,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-11-26T14:29:32Z\",\"WARC-Record-ID\":\"<urn:uuid:52f19000-d217-499f-9877-a2e3fc8fc7cc>\",\"Content-Length\":\"66820\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:d829dfbe-9bb7-498b-92c1-20ce43668ff3>\",\"WARC-Concurrent-To\":\"<urn:uuid:a8d27c05-fab5-4c0c-a081-2e5e5d45131c>\",\"WARC-IP-Address\":\"192.0.78.12\",\"WARC-Target-URI\":\"https://quantitysystem.wordpress.com/2010/04/15/work-and-torque-solution/\",\"WARC-Payload-Digest\":\"sha1:HATUJEK376C4S5N6RRC5DWKW7B2GSLIP\",\"WARC-Block-Digest\":\"sha1:3FXA3PYUEWXXK7UQZ6A2E7XZHUSWOXWM\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-50/CC-MAIN-2020-50_segments_1606141188800.15_warc_CC-MAIN-20201126142720-20201126172720-00506.warc.gz\"}"} |
https://members.kidpid.com/ask/reply/49836/ | [
"community around the world.\n\nActivity Discussion Math MATHS Reply To: MATHS\n\n• ### Aseem\n\nMember\nJune 4, 2023 at 8:44 am\n2\n\nTo simplify the expression (2x + 3y) – (4x – 2y), we need to distribute the negative sign to the terms inside the parentheses. Here are the steps to simplify it:\n\nStep 1: Distribute the negative sign to the terms inside the second set of parentheses:\n\n(2x + 3y) – 4x + 2y.\n\nStep 2: Combine like terms. In this case, we can combine the x terms and the y terms separately:\n\n2x – 4x + 3y + 2y.\n\nStep 3: Simplify the x terms by combining the coefficients:\n\n(2 – 4)x + 3y + 2y.\n\nStep 4: Simplify the y terms by combining the coefficients:\n\n-2x + 5y.\n\nTherefore, the simplified expression for (2x + 3y) – (4x – 2y) is -2x + 5y.\n\n+"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.7227888,"math_prob":0.9954003,"size":706,"snap":"2023-40-2023-50","text_gpt3_token_len":237,"char_repetition_ratio":0.14814815,"word_repetition_ratio":0.11510792,"special_character_ratio":0.3371105,"punctuation_ratio":0.1632653,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9945438,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-10-04T19:20:17Z\",\"WARC-Record-ID\":\"<urn:uuid:7a47393d-c72b-4c97-b303-c336c81632fe>\",\"Content-Length\":\"112330\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:d3bd08c6-6235-48e3-afb5-c31a66e199a5>\",\"WARC-Concurrent-To\":\"<urn:uuid:b9439a94-9403-422f-9bc0-31627e51b529>\",\"WARC-IP-Address\":\"68.178.152.103\",\"WARC-Target-URI\":\"https://members.kidpid.com/ask/reply/49836/\",\"WARC-Payload-Digest\":\"sha1:GFOFEYKCRVV3VILOL6BC6IQ4FW4JUFKT\",\"WARC-Block-Digest\":\"sha1:TZQOYODACFWQRO6HBKEGVD3DDII5NUS5\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-40/CC-MAIN-2023-40_segments_1695233511406.34_warc_CC-MAIN-20231004184208-20231004214208-00070.warc.gz\"}"} |
https://electronics.stackexchange.com/questions/538187/how-are-two-definitions-of-baud-rate-same | [
"# How are two definitions of baud rate same?\n\nThe bit rate V baud rate has been a confusing topic for me lately. I feel like I am clear about the difference between these two.\n\nBut going through the definitions of baud rate, I find two different definitions in use:\n\n1. A baud rate is the number of times a signal in a communications channel changes state or varies. For example, a 2400 baud rate means that the channel can change states up to 2400 times per second. The term “change state” means that it can change from 0 to 1 or from 1 to 0 up to X (in this case, 2400) times per second. (This is the definition from my teacher's notes.)\n1. Baud rate as the no. of symbols transmitted per second. Consider a symbol \"A\" which is encoded as \"0100 0001\" in ASCII format. If I send this symbol within 1 second, I have bitrate of 8 bits per second.\n\nFor baud rate: According to first definition, baud rate is 1 baud per second.\n\nBut according to second definition, the baud rate is 3 bauds per second since the signal changes its state three times (0 -> 1 -> 00000 -> 1).\n\nSo how do these two definitions link together? I can't see any match between these two definitions with \"my\" level of knowledge. Thank you!!\n\nAnd how is the calculation done in following image? I understand the calculation for the bit rate but how is baud rate calculated?",
null,
"• The letter 'A' is not a symbol in this context. In this context, a symbol is a quantum of information that can be transmitted on the communication channel. Dec 19 '20 at 15:20\n• @ElliotAlderson would you elaborate please? Dec 19 '20 at 15:24\n• Sounds like a non-standard definition in the second one. \"Symbol\" sounds vague. I agree with Elliot's comment. It should be referring to the least indivisible information or something in the context you read. The first one is standard definition though. Dec 19 '20 at 15:49\n• @Mitu Raj The terms symbol and symbol rate are not vague and have been in use for at least 40 years. Dec 19 '20 at 16:37\n• I would be curious to see any reliable source which correctly defines what is \"Symbol\" in information theory. As of the above definition of baudrate, does a Symbol means the same as \"number of transitions of a signal\" in a second (cz that's what baudrate means)? I don't think so. It has different meanings as per how the information is encoded. Dec 19 '20 at 19:31\n\nData transmission has always some bits of overhead for giving the payload data a frame so that decoding it is possible with some certainty. Thus sync signals and also parity signals are there. On bus systems further multiplexing (routing) information is part of it. In modern systems there is even some parts used for data priorization (effectively part of the routing duty) and for media quality measurement such as DSL signal optimisation.\n\nFor RS232 you have for example the start and stop bits, and the optional parity bits - applied to each character bit (might it be 5 to 8 bits long). For Ethernet you have the whole IP header that encapsulates your payload data in a package. Further there are For CAN bus there is an address field and some checksums along with other bits. For bit-serial busses like I2C, SPI and alike you often will find read-write bits, address bits and also start/stop bits along with checksums and even feedback/confirmation/error bits.\n\nRationale: What's sent on the channel is more than just the data bits you want to be sent but also some extra data making it possible for the receiver to really decode your data bits. For this some extra bits are added and later on removed again. This extra bits are counted on the channel's baud rate but they have to be subtracted to estimate the maximum transfer data rate that you as a user will e able to achieve.\n\nWhat else? Parallel busses have more than one wire and thus are able to transmit multiple bits per transmission step. Further the control flow is realized as separate wires. Thus an 8 wire + control flow wire interface can have 8 times the data rate than the baud rate.\n\nThe key word \"symbols\" is a term found in modem technology. With a certain signal shape more than one bit is encoded. This can be for example multiple tone signals send in parallel (DTMF) or other types of modulation (FSK, PSK, QAM, ...). Thus meaning the tone frequency and the switching speed between sent symbols (no longer bits) is quite decoupled. (Of course there is the Nyquist theorem of limiting a channel to some maximum raw data transmission capability.) So if you have for example 64-value quadrature amplitude modulation - then you will have a bit equivalent to those 64 values of useable channel capacity that is sent and received on each of the baud-rate steps. 64 values would mean 6 bits of raw data per baud-rate step. (Still even with this a few values might be reserved in order to achieve various types of bit and byte border synchronization as well as for channel duties.)\n\n• Channel overhead is not part of the question (although it needs to be considered at link level). Dec 19 '20 at 17:00\n• Good point, Peter. The question was not that clear for me if this item in the stack has even awareness - it definitely contributes in a larger amount of cases to the difference between user seen capacity and baud rate. - Further paragraphs on parallel busses and on /symbol/ based transmissions (or modulated signals) were there already. Dec 20 '20 at 9:32\n\nThe letter 'A' is not a symbol in this context. A symbol is a recognizable distinct value on the communication channel; it is a quantum of transmittable information.\n\nFor a binary communication channel, a symbol is either a 0 or a 1. If you are talking about conventional UART kinds of transmission, then every transmitted byte of information will also need a start symbol and a stop symbol. So, you have to transmit 10 symbols in order to transmit 8 bits of information. The maximum information (bit) rate is 8/10 of the maximum baud rate.\n\nSome kinds of communication can send multiple bits per symbol. In the old fashioned touch-tone dual-tone multiple-frequency (DTMF) telephone systems, pressing a button on the keypad caused a sound to be transmitted. Each sound was a symbol. Each sound comprised two audio frequencies, one frequency corresponding to a row on the keypad and the other frequency corresponding to the column. With four rows and four columns, each sound corresponded to 1 of 16 keys. So, each sound conveyed 4 bits of information.\n\n• Actually, each button press transmitted two tones, hence the name \"dual tone\". Dec 19 '20 at 16:09\n• So in this, a symbol would be 1 or 0? If that is the case there would be 8 symbols. So, 8 baud per second. Then how is it equal to 3 state changes in the signal? Dec 19 '20 at 16:10\n• @Hearth You are right, I'll change that to something else. Dec 19 '20 at 16:39\n• @G-aura-V You are comparing apples and cabbages. You talk about two completely different communication systems, one that encodes a single bit per baud and another that encodes three bits per baud. Dec 19 '20 at 16:41\n• @Elliot Alderon I didn't get you. Which system in the question encodes three bits per baud? Dec 20 '20 at 3:37\n\nbit rate = (bits/symbol)*(symbols/second)\n\nIf you are going to transmit three bits at a time you have to use eight different frequencies (as in the case of FSK). So, each symbol will have three bits and the symbol rate (which we call baud rate) will be decided prior to transmission. This is your 'second' definition. For some modulation schemes such as ASK, BPSK, and PSK, the bit rate equals the baud rate."
] | [
null,
"https://i.stack.imgur.com/4ZfD3.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.93958485,"math_prob":0.90499586,"size":1288,"snap":"2021-43-2021-49","text_gpt3_token_len":306,"char_repetition_ratio":0.16666667,"word_repetition_ratio":0.0,"special_character_ratio":0.25543478,"punctuation_ratio":0.09811321,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.95398897,"pos_list":[0,1,2],"im_url_duplicate_count":[null,1,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-11-27T20:58:22Z\",\"WARC-Record-ID\":\"<urn:uuid:d3a428cf-d6cf-44d0-9441-c63708cc440f>\",\"Content-Length\":\"167937\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:33369717-d2f7-4746-875b-c699a6597f37>\",\"WARC-Concurrent-To\":\"<urn:uuid:c6aaef65-0dbc-44a0-ba48-7d2f55549b4d>\",\"WARC-IP-Address\":\"151.101.129.69\",\"WARC-Target-URI\":\"https://electronics.stackexchange.com/questions/538187/how-are-two-definitions-of-baud-rate-same\",\"WARC-Payload-Digest\":\"sha1:POVCAZANA5C3B6GPEYMYVIRGQC725W3T\",\"WARC-Block-Digest\":\"sha1:YNMZAT3X5RGUN5RG42FQZYP2G2NHFNS5\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-49/CC-MAIN-2021-49_segments_1637964358233.7_warc_CC-MAIN-20211127193525-20211127223525-00007.warc.gz\"}"} |
https://math.stackexchange.com/questions/1814721/solutions-of-lfloor-4x-rfloor-lfloor-3x-rfloor-1 | [
"Solutions of $\\lfloor 4x\\rfloor+\\lfloor 3x\\rfloor=1$\n\nFind all solutions of $$\\lfloor 4x\\rfloor+\\lfloor 3x\\rfloor=1$$\n\nI have no idea as to how to go about this question. I would be grateful if somebody would please show me how to solve such questions.\n\nMany thanks!\n\n• Yes Sir, it is the floor function. – user342209 Jun 5 '16 at 16:24\n\nIf $x\\le0$, then the LHS is non-positive.\n\nSo $x$ has to be positive. Since both terms on the LHS are integers with $\\lfloor 3x\\rfloor\\le \\lfloor 4x\\rfloor$, we have $$\\lfloor 4x\\rfloor=1\\quad \\text{and}\\quad \\lfloor 3x\\rfloor =0$$ from which $\\color{red}{1/4\\le x\\lt 1/3}$ follows.\n\n• Could you please elaborate a bit? I couldn't understand the part about $\\lfloor 3x\\rfloor\\le \\lfloor 4x\\rfloor$. How do we compare between $\\lfloor ax\\rfloor$ and $\\lfloor bx\\rfloor$ for any general $x$ (ie positive or negative values of $x$), where $a,b$ are constants? – user342209 Jun 5 '16 at 16:45\n• @user342209 : For $x\\gt 0$, we have $3x\\lt 4x$, and so $\\lfloor 3x\\rfloor\\le \\lfloor 4x\\rfloor$. Does this help or not? – mathlove Jun 5 '16 at 16:47\n• @user342209: In general, if $ax\\le bx$, then $\\lfloor ax\\rfloor\\le\\lfloor bx\\rfloor$. – mathlove Jun 5 '16 at 16:55\n• Beat me to it. I was typing on my phone. – user223391 Jun 5 '16 at 16:57\n• @mathlove It helps a lot! – user342209 Jun 5 '16 at 17:06\n\nHint: $$\\lfloor4x \\rfloor+\\lfloor3x \\rfloor=1$$ $$4x-1<\\lfloor4x \\rfloor\\le4x$$ $$3x-1<\\lfloor3x \\rfloor\\le3x$$ Then $$3x+4x-2<\\lfloor4x \\rfloor+\\lfloor3x \\rfloor\\le3x+4x$$ $$7x-2\\le1<7x$$ $$\\frac 17< x\\le\\frac37$$\n\nCase 1) $\\frac 17< x<\\frac14$\n\nCase 2) $\\frac 14\\le x<\\frac13$\n\nCase 3) $\\frac 13\\le x<\\frac37$\n\nAnswer: $$\\frac 14\\le x<\\frac13$$\n\n• Sir, isn't $[x]\\le x$? Then how can $4x\\le\\lfloor4x \\rfloor<4x+1$? – user342209 Jun 5 '16 at 16:32\n• You probably mean $4x-1$ and $4x$. – user223391 Jun 5 '16 at 16:36\n\nLet $a+b=1$ where $a,b\\in \\Bbb{Z}$.\n\nNote if $x <0$ then $\\lfloor 3x\\rfloor<0$ and likewise with $4x$. So $a,b\\geq 0$.\n\nSo the equation boils down to $a=1$ and $b=0$ or vice versa. Note that $\\lfloor 4x\\rfloor\\geq \\lfloor 3x\\rfloor$ so you need to find $x$ so that $\\lfloor 3x\\rfloor=0$ and $\\lfloor 4x \\rfloor = 1$.\n\nYou want $0<3x<1$ and $1\\leq 4x< 2$. That is, $1/4 \\leq x < 1/3$."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.69032824,"math_prob":0.99996924,"size":1428,"snap":"2019-26-2019-30","text_gpt3_token_len":593,"char_repetition_ratio":0.18820225,"word_repetition_ratio":0.30331755,"special_character_ratio":0.37114847,"punctuation_ratio":0.07491857,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99995136,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-06-20T15:23:49Z\",\"WARC-Record-ID\":\"<urn:uuid:c42fd27c-99c6-417c-9c26-dadf91b19505>\",\"Content-Length\":\"156706\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e704ef23-f007-48e9-9235-74ba5a5020d0>\",\"WARC-Concurrent-To\":\"<urn:uuid:e9c95090-e394-4e3d-a2c5-7dcacf104c35>\",\"WARC-IP-Address\":\"151.101.1.69\",\"WARC-Target-URI\":\"https://math.stackexchange.com/questions/1814721/solutions-of-lfloor-4x-rfloor-lfloor-3x-rfloor-1\",\"WARC-Payload-Digest\":\"sha1:F3AGAXWRB77TV22W43PBU5U6ICGM3P25\",\"WARC-Block-Digest\":\"sha1:WHQ4Y3J22A3XYV2KLJQUNNIPTNGBFNGO\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-26/CC-MAIN-2019-26_segments_1560627999261.43_warc_CC-MAIN-20190620145650-20190620171650-00153.warc.gz\"}"} |
https://www.designcise.com/web/tutorial/how-to-get-key-value-pair-from-url-query-string-in-php | [
"How To Get Key/Value Pair From URL Query String In PHP?\n\nA look at different ways to retrieve the query string and parameter values therein\n\n• By Daniyal Hamid\n• October 15, 2015\n\nIn this article we look at different ways in PHP to retrieve the query string and its parameter values from a URL. We'll be using the following string for all the examples in this article:\n\nhttp://www.designcise.com/?key1=value1&key2=value2\n\nRetrieving The Query String\n\nQuery String Of Current URL:\n\nUsing \\$_SERVER['QUERY_STRING'] in PHP we can get the full query string from the current URL. For example:\n\necho \\$_SERVER['QUERY_STRING'];\n\n// Output: key1=value1&key2=value2\n\nQuery String From A String\n\nTo retrieve the query string from a string we can use the parse_url function. For example:\n\necho parse_url('http://www.designcise.com/?key1=value1&key2=value2', PHP_URL_QUERY);\n\n// Output: key1=value1&key2=value2\n\nQuery String Parameters As An Array\n\nUsing The \\$_GET Array:\n\nUsing \\$_GET array in PHP we can directly access any key/value pair in the current URL. For example:\n\necho \\$_GET['key1']; // Output: value1\n\nParsing A Query String\n\nWhen we have all the key/value pairs in a single string, we can use the parse_str function to convert the key/value pairs to an array:\n\n// method #1\nparse_str(\\$_SERVER['QUERY_STRING'], \\$output);\n\n// method #2\nparse_str(parse_url('http://www.designcise.com/?key1=value1&key2=value2', PHP_URL_QUERY), \\$output);\necho print_r(\\$output, TRUE);\n\n// Output:\nArray (\n['key1'] => \"value1\"\n['key2'] => \"value2\"\n)\n\nHandling Duplicate Keys In A Query String:\n\nUsing either of the two methods explained above, the output of duplicate keys in a query string would be a child array for that key with numerically indexed values. For demonstration purposes, consider the output of the following url:\n\nhttp://www.designcise.com/?key[]=value1&key[]=value2\n\n// Output:\nArray (\n['key'] => Array (\n => test1\n => test2\n)\n)\n\nThings To Remember:\n\nWhen using the methods explained above, remember the following are true:\n\n• Using \\$_GET would be the fastest way to access a key/value pair in the current url. Wherever possible, this should be the preferred choice.\n• Both parse_str and \\$_GET automatically urldecode values, which means any %## encoding is decoded in the given string. Plus symbols (i.e. +) are decoded to a space character. If this is not the behavior you're looking for, then you may use \\$_SERVER['QUERY_STRING'] to retrieve the entire query string in its original form or call urlencode on individual values.\n• Duplicate key names followed by square brackets (for example, ?key[]=value1&key[]=value2) create a child array for that key with numerically indexed values."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.5945473,"math_prob":0.7432149,"size":2477,"snap":"2019-43-2019-47","text_gpt3_token_len":604,"char_repetition_ratio":0.12252325,"word_repetition_ratio":0.056179777,"special_character_ratio":0.25878078,"punctuation_ratio":0.14254385,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9522122,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-10-16T16:57:04Z\",\"WARC-Record-ID\":\"<urn:uuid:1b7dc6f5-4495-479c-8703-fe6359ac9fd1>\",\"Content-Length\":\"18132\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:167ab67d-4e04-4aed-b8be-163ac7bc15f6>\",\"WARC-Concurrent-To\":\"<urn:uuid:7cd7d837-ac50-41d3-94d0-de27e9f97f74>\",\"WARC-IP-Address\":\"213.32.120.154\",\"WARC-Target-URI\":\"https://www.designcise.com/web/tutorial/how-to-get-key-value-pair-from-url-query-string-in-php\",\"WARC-Payload-Digest\":\"sha1:FDA2EO6JIZYP3T53W3SUVVZB5ZX3CCD6\",\"WARC-Block-Digest\":\"sha1:2IH7UV4QWQ5OZJ2YF6FZKLMQZH7AWCOL\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-43/CC-MAIN-2019-43_segments_1570986669057.0_warc_CC-MAIN-20191016163146-20191016190646-00378.warc.gz\"}"} |
https://www.fmz.com/strategy/380219 | [
"# Candle Strength\n\nAuthor: Zer3192, Date: 2022-08-27 11:57:02\nTags:\n\n```/*backtest\nstart: 2021-05-08 00:00:00\nend: 2022-05-07 23:59:00\nperiod: 4h\nbasePeriod: 15m\nexchanges: [{\"eid\":\"Futures_Binance\",\"currency\":\"BTC_USDT\"}]\n*/\n// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/\n\n//@version=5\nindicator(\"Candle Strength\",overlay = true )\n\n//round function for rounding up to n decimal places\n//Thanks to Proper Round Function - QuantNomad\n\nroundn(x, n) =>\nmult = 1\nif n != 0\nfor i = 1 to math.abs(n) by 1\nmult *= 10\nmult\n\nn >= 0 ? math.round(x * mult) / mult : math.round(x / mult) * mult\n\n//calculating strength\ngreen = roundn(((close-low)/(high-low) *100), 2)\nred = roundn(((high-close)/(high-low)*100), 2)\n\nif (close>open)\nl = label.new(x = bar_index,y = close,text=str.tostring(green) + \" %\",color=color.green,textcolor = color.white,style=label.style_label_up)\nlabel.set_yloc(l,yloc.belowbar)\nstrategy.entry(\"Enter Long\", strategy.long)\nelse if (open > close)\nl2 = label.new(x = bar_index,y = close,text=str.tostring(red)+ \" %\",color=color.red,textcolor=color.white,style=label.style_label_down)\nlabel.set_yloc(l2,yloc = yloc.abovebar)\nstrategy.entry(\"Enter Short\", strategy.short)\n\n```\n\nMore"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.5073403,"math_prob":0.9112602,"size":1280,"snap":"2023-40-2023-50","text_gpt3_token_len":407,"char_repetition_ratio":0.09874608,"word_repetition_ratio":0.013071896,"special_character_ratio":0.35078126,"punctuation_ratio":0.23791821,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9764429,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-12-05T00:03:06Z\",\"WARC-Record-ID\":\"<urn:uuid:3c03f342-1afa-43df-ab06-ae9bea4e37e2>\",\"Content-Length\":\"8226\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:bf3db980-0220-462f-a70e-94b54c208fa0>\",\"WARC-Concurrent-To\":\"<urn:uuid:6a2ce15c-67ac-431c-810a-e54b8f42076e>\",\"WARC-IP-Address\":\"34.92.158.77\",\"WARC-Target-URI\":\"https://www.fmz.com/strategy/380219\",\"WARC-Payload-Digest\":\"sha1:3E33F7FBXYF3BXN3PVWGPY4DDQPFLT7B\",\"WARC-Block-Digest\":\"sha1:SLFMKTNMMMYLS4RFBTE62ANWD45WOAUG\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-50/CC-MAIN-2023-50_segments_1700679100535.26_warc_CC-MAIN-20231204214708-20231205004708-00571.warc.gz\"}"} |
http://aspalliance.com/36_Creating_Excel_XP_spreadsheets_by_using_NET_and_XML | [
"",
null,
"",
null,
"",
null,
"",
null,
"",
null,
"Print",
null,
"Add To Favorites",
null,
"Email To Friend",
null,
"Rate This Article Creating Excel XP spreadsheets by using .NET and XML\n page 1 of 1\nPublished: 26 Sep 2003\nUnedited - Community Contributed\nAbstract\nExcel XP has a cool feature related to XML as the product can easily read and write properly-structured XML documents, run web queries against properly-structured XML data sources and save entire workbooks as XML spreadsheets. This article demonstrates one view to the utilization of this feature in .NET, namely creating a basic spreadsheet that has formulas.",
null,
"by\nFeedback\nViews (Total / Last 10 Days): 17809/ 39\n\nThe article\n\nSource XML\n\n<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<sales>\n<product>\n<name>CD</name>\n<price>20</price>\n<sold>15</sold>\n</product>\n<product>\n<name>Book</name>\n<price>50</price>\n<sold>7</sold>\n</product>\n<product>\n<name>Pen</name>\n<price>2</price>\n<sold>18</sold>\n</product>\n</sales>\n\nTarget XML\n\nThis is an example of the format Excel can open straight as a file from file system or as a web page and then produce a working spreadsheet with formulas. Note that this is a reduced version to keep the example concise.\nIf you save an Excel spreadsheet as XML and take a look at it, there would be content related to worksheet's options, protection, document's properties and so on. However, those are optional elements in the XML format and therefore stripped out of this example.\n\n<?xml version=\"1.0\" encoding=\"utf-8\"?>\n\n<Styles>\n<Style ss:ID=\"s1\">\n<Font x:Family=\"Swiss\" ss:Bold=\"1\" />\n</Style>\n</Styles>\n\n<Worksheet ss:Name=\"Sheet1\">\n<Table>\n<Row>\n<Cell>\n<Data ss:Type=\"String\">Demonstration spreadsheet created with .NET</Data>\n</Cell>\n</Row>\n\n<Row ss:Index=\"3\">\n<Cell ss:StyleID=\"s1\">\n<Data ss:Type=\"String\">Product</Data>\n</Cell>\n<Cell ss:StyleID=\"s1\">\n<Data ss:Type=\"String\">Sold</Data>\n</Cell>\n<Cell ss:StyleID=\"s1\">\n<Data ss:Type=\"String\">Price</Data>\n</Cell>\n<Cell ss:StyleID=\"s1\">\n<Data ss:Type=\"String\">Sum</Data>\n</Cell>\n</Row>\n<Row>\n<Cell>\n<ss:Data ss:Type=\"String\">CD</ss:Data>\n</Cell>\n<Cell>\n<ss:Data ss:Type=\"Number\">15</ss:Data>\n</Cell>\n<Cell>\n<Data ss:Type=\"Number\">20</Data>\n</Cell>\n<Cell ss:Formula=\"=RC[-2]*RC[-1]\">\n</Cell>\n</Row>\n<Row>\n<Cell>\n<ss:Data ss:Type=\"String\">Book</ss:Data>\n</Cell>\n<Cell>\n<ss:Data ss:Type=\"Number\">7</ss:Data>\n</Cell>\n<Cell>\n<Data ss:Type=\"Number\">50</Data>\n</Cell>\n<Cell ss:Formula=\"=RC[-2]*RC[-1]\">\n</Cell>\n</Row>\n<Row>\n<Cell>\n<ss:Data ss:Type=\"String\">Pen</ss:Data>\n</Cell>\n<Cell>\n<ss:Data ss:Type=\"Number\">18</ss:Data>\n</Cell>\n<Cell>\n<Data ss:Type=\"Number\">2</Data>\n</Cell>\n<Cell ss:Formula=\"=RC[-2]*RC[-1]\">\n</Cell>\n</Row>\n<Row>\n<Cell ss:Index=\"3\" ss:StyleID=\"s1\">\n<Data ss:Type=\"String\">Sum</Data>\n</Cell>\n<Cell ss:Formula=\"=R[-3]C+R[-2]C+R[-1]C\">\n</Cell>\n</Row>\n</Table>\n</Worksheet>\n</Workbook>\n\n<Style ss:ID=\"s1\">\n<Font x:Family=\"Swiss\" ss:Bold=\"1\" />\n</Style>\n\nThis declares a style that can be used at the spreadsheet by referring to ss:StyleID=\"s1\"\n\n<Worksheet ss:Name=\"Sheet1\">\n\nDeclares a worksheet with name “Sheet 1”.\n\n<Data ss:Type=\"String\">\n\nSpecifies the data type of the content of the cell.\n\n<Row ss:Index=\"3\">\n\nSpecifies that the row is placed at the third row at the spreadsheet.\n\n<Cell ss:Index=\"3\"…>\n\nSpecifies that the cell is placed at the third cell in this row at the spreadsheet.\n\n<Cell ss:Formula=\"=R[-3]C+R[-2]C+R[-1]C\"></Cell>\n\nSpecifies the formula to be used to produce the content for the cell. The syntax is the basic RC syntax that uses relative locations. R means row and C means cell.\n\nIf you want to know more about the exact syntax, see resources provided at the end of this article.\n\nSo?\n\nWell, it should be obvious that creating these Excel compatible XML files is very easy task in .NET. You could create the XML for example using XSLT or DOM and output it from web page using built-in Xml Control. Consider also the benefits if these docs i.e. Excel spreadsheets would be transmitted using XML web services. Also according to Microsoft the Office 2003 will have better support for XML. The result XML provided earlier was successfully tested with beta version of Excel 2003 by Thomas Johansen, http://authors.aspalliance.com/aylar .\n\nAs much as it is cool to have this kind feature, there are also restrictions. You can't save charts, OLE objects, VBA code etc. special features. I've included sample codes for the XSLT approach. It contains the source XML, the XSLT style sheet with extension C# class and the page to test the transformation and to produce the result XML. If you try to open the page from your server using Excel XP, you get fully working spreadsheet that has formulas.\n\nResources\n\nXML in Excel and the Spreadsheet component (MSDN)\n\nTransform XML Files when importing into Microsoft Excel 2002 (MSDN)",
null,
"",
null,
"",
null,
"",
null,
"",
null,
""
] | [
null,
"http://aspalliance.com/images/clear.gif",
null,
"http://aspalliance.com/images/clear.gif",
null,
"http://aspalliance.com/images/clear.gif",
null,
"http://aspalliance.com/images/clear.gif",
null,
"http://aspalliance.com/images/icons_11x8/icon-print.gif",
null,
"http://aspalliance.com/images/icons_11x8/icon-favorite.gif",
null,
"http://aspalliance.com/images/icons_11x8/icon-envelope.gif",
null,
"http://aspalliance.com/images/icons_11x8/icon-rate.gif",
null,
"http://aspalliance.com/images/photos/8cbd3d4f-1d72-4777-9409-46f875fcc8f8_80_80.jpg",
null,
"http://aspalliance.com/images/gear_16x16.gif",
null,
"http://aspalliance.com/images/clear.gif",
null,
"http://aspalliance.com/images/clear.gif",
null,
"http://aspalliance.com/images/clear.gif",
null,
"http://aspalliance.com/images/clear.gif",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.63701177,"math_prob":0.47267985,"size":4586,"snap":"2020-34-2020-40","text_gpt3_token_len":1315,"char_repetition_ratio":0.16302924,"word_repetition_ratio":0.03797468,"special_character_ratio":0.28892282,"punctuation_ratio":0.13943355,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.95936954,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,5,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-08-06T07:24:28Z\",\"WARC-Record-ID\":\"<urn:uuid:81ab437c-6295-47f4-9c83-3010aa99fd6c>\",\"Content-Length\":\"84173\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:9a9c6c41-8847-49aa-85f8-f1789eb9cead>\",\"WARC-Concurrent-To\":\"<urn:uuid:d3303ab1-e2ea-4f7a-9316-a168d624d895>\",\"WARC-IP-Address\":\"76.74.234.215\",\"WARC-Target-URI\":\"http://aspalliance.com/36_Creating_Excel_XP_spreadsheets_by_using_NET_and_XML\",\"WARC-Payload-Digest\":\"sha1:TJQUMP5NYBDBOVVZEFQUWVWBZWZQ5MXW\",\"WARC-Block-Digest\":\"sha1:BIR5OOR7RYOUMMLCFBUGA2E35TF4MR26\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-34/CC-MAIN-2020-34_segments_1596439736883.40_warc_CC-MAIN-20200806061804-20200806091804-00389.warc.gz\"}"} |
https://numbermatics.com/n/920736/ | [
"# 920736\n\n## 920,736 is an even composite number composed of four prime numbers multiplied together.\n\nWhat does the number 920736 look like?\n\nThis visualization shows the relationship between its 4 prime factors (large circles) and 72 divisors.\n\n920736 is an even composite number. It is composed of four distinct prime numbers multiplied together. It has a total of seventy-two divisors.\n\n## Prime factorization of 920736:\n\n### 25 × 32 × 23 × 139\n\n(2 × 2 × 2 × 2 × 2 × 3 × 3 × 23 × 139)\n\nSee below for interesting mathematical facts about the number 920736 from the Numbermatics database.\n\n### Names of 920736\n\n• Cardinal: 920736 can be written as Nine hundred twenty thousand, seven hundred thirty-six.\n\n### Scientific notation\n\n• Scientific notation: 9.20736 × 105\n\n### Factors of 920736\n\n• Number of distinct prime factors ω(n): 4\n• Total number of prime factors Ω(n): 9\n• Sum of prime factors: 167\n\n### Divisors of 920736\n\n• Number of divisors d(n): 72\n• Complete list of divisors:\n• Sum of all divisors σ(n): 2751840\n• Sum of proper divisors (its aliquot sum) s(n): 1831104\n• 920736 is an abundant number, because the sum of its proper divisors (1831104) is greater than itself. Its abundance is 910368\n\n### Bases of 920736\n\n• Binary: 111000001100101000002\n• Base-36: JQG0\n\n### Squares and roots of 920736\n\n• 920736 squared (9207362) is 847754781696\n• 920736 cubed (9207363) is 780558346679648256\n• The square root of 920736 is 959.5498944821\n• The cube root of 920736 is 97.2848114109\n\n### Scales and comparisons\n\nHow big is 920736?\n• 920,736 seconds is equal to 1 week, 3 days, 15 hours, 45 minutes, 36 seconds.\n• To count from 1 to 920,736 would take you about three days!\n\nThis is a very rough estimate, based on a speaking rate of half a second every third order of magnitude. If you speak quickly, you could probably say any randomly-chosen number between one and a thousand in around half a second. Very big numbers obviously take longer to say, so we add half a second for every extra x1000. (We do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!)\n\n• A cube with a volume of 920736 cubic inches would be around 8.1 feet tall.\n\n### Recreational maths with 920736\n\n• 920736 backwards is 637029\n• The number of decimal digits it has is: 6\n• The sum of 920736's digits is 27\n• More coming soon!"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8160243,"math_prob":0.9603531,"size":3414,"snap":"2021-31-2021-39","text_gpt3_token_len":1013,"char_repetition_ratio":0.11994135,"word_repetition_ratio":0.034843206,"special_character_ratio":0.4004101,"punctuation_ratio":0.14114115,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99316543,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-09-28T19:54:36Z\",\"WARC-Record-ID\":\"<urn:uuid:38748c6c-99e8-49f7-9e87-3796c1c4063d>\",\"Content-Length\":\"21898\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:d14c55d4-0821-4946-a0f6-cc8b26313625>\",\"WARC-Concurrent-To\":\"<urn:uuid:c2d4074c-db4d-468a-9178-c4b6f12af07c>\",\"WARC-IP-Address\":\"72.44.94.106\",\"WARC-Target-URI\":\"https://numbermatics.com/n/920736/\",\"WARC-Payload-Digest\":\"sha1:TWUNUYAUVBIWS6NB4JMMEJMQD2OGDGUG\",\"WARC-Block-Digest\":\"sha1:RYJDIK2PWSXJY7C46ZOBA2YPQM2WAJTM\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-39/CC-MAIN-2021-39_segments_1631780060882.17_warc_CC-MAIN-20210928184203-20210928214203-00513.warc.gz\"}"} |
https://piping-designer.com/index.php/disciplines/electrical/2517-wavelength-velocity | [
"# Wavelength Velocity\n\nWritten by Jerry Ratzlaff on . Posted in Electrical Engineering\n\n## Wavelength Velocity formula\n\n $$\\large{ v_w = \\frac { f } { \\lambda } }$$\n\n### Where:\n\n Units English Metric $$\\large{ v_w }$$ = wavelength velocity $$\\large{\\frac{ft}{sec}}$$ $$\\large{\\frac{m}{s}}$$ $$\\large{ f }$$ = frequency $$\\large{Hz}$$ $$\\large{Hz}$$ $$\\large{ \\lambda }$$ (Greek symbol \\lambda) = wavelength $$\\large{ft}$$ $$\\large{m}$$",
null,
""
] | [
null,
"https://piping-designer.com/images/Piping%20Designer%20Gallery/P-D_Logo_1.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.5519477,"math_prob":1.0000091,"size":368,"snap":"2022-40-2023-06","text_gpt3_token_len":129,"char_repetition_ratio":0.27747253,"word_repetition_ratio":0.0,"special_character_ratio":0.41847825,"punctuation_ratio":0.022727273,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":1.0000072,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-09-28T18:56:29Z\",\"WARC-Record-ID\":\"<urn:uuid:9419bbbf-3b82-4085-b891-8243d7a2c96c>\",\"Content-Length\":\"27082\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:46b23d93-bf52-4102-ae8d-f01e762d5568>\",\"WARC-Concurrent-To\":\"<urn:uuid:f0a313d4-1981-4d60-8f48-2a20506da993>\",\"WARC-IP-Address\":\"200.225.40.42\",\"WARC-Target-URI\":\"https://piping-designer.com/index.php/disciplines/electrical/2517-wavelength-velocity\",\"WARC-Payload-Digest\":\"sha1:2BSGD7EZLMJ73P6B5F364OPZKKNBONYG\",\"WARC-Block-Digest\":\"sha1:VTZCXGCJBKA5O3WFV4MPH3ELV4HIU7WD\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-40/CC-MAIN-2022-40_segments_1664030335276.85_warc_CC-MAIN-20220928180732-20220928210732-00720.warc.gz\"}"} |
https://texar-pytorch.readthedocs.io/en/latest/_modules/texar/torch/run/metric/summary.html | [
"# Source code for texar.torch.run.metric.summary\n\n```# Copyright 2019 The Texar Authors. All Rights Reserved.\n#\n# you may not use this file except in compliance with the License.\n# You may obtain a copy of the License at\n#\n#\n# Unless required by applicable law or agreed to in writing, software\n# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n# See the License for the specific language governing permissions and\n\"\"\"\nExecutor metrics for summaries.\n\"\"\"\n\nfrom collections import deque\nfrom typing import Any, Deque, Optional, Sequence\nimport weakref\n\nimport numpy as np\nfrom torch.optim.optimizer import Optimizer\n\nfrom texar.torch.run.metric.base_metric import StreamingMetric\n\n__all__ = [\n\"Average\",\n\"AveragePerplexity\",\n\"RunningAverage\",\n\"LR\",\n]\n\n[docs]class Average(StreamingMetric[float, float]):\nr\"\"\"The average of a specific predicted value.\n\nAverage is a :class:`~texar.torch.run.metric.StreamingMetric`, requires only\npredicted values. Average values are unbounded :class:`float` numbers. By\ndefault, lower values are better, but the behavior can be configured.\n\nKeyword Args:\npred_name (str): Name of the predicted value. This will be used as the\nkey to the dictionary returned by the model. Defaults to ``\"loss\"``.\nhigher_is_better (bool, optional): If specified, the\n:attr:`higher_is_better` attribute for the instance is overwritten\nby the specified value. Defaults to `False`.\n\"\"\"\nhigher_is_better = False\nrequires_label = False\n\nsum: float\n\ndef __init__(self, *, pred_name: str = \"loss\",\nhigher_is_better: bool = False):\n# pylint: disable=useless-super-delegation\nsuper().__init__(pred_name=pred_name, higher_is_better=higher_is_better)\n\ndef reset(self) -> None:\nsuper().reset()\nself.sum = 0.0\n\ndef add(self, predicted: Sequence[float], _) -> None:\nself.count += len(predicted)\nself.sum += sum(predicted)\n\ndef value(self) -> float:\nif self.count == 0:\nreturn 0.0\nreturn self.sum / self.count\n\n[docs]class AveragePerplexity(Average):\n# TODO: Create a `WeightedAverage` class that takes `(value, weight)`\nhigher_is_better = False\n\ndef add(self, predicted: Sequence[float], _) -> None:\n\n[docs]class RunningAverage(StreamingMetric[float, float]):\nr\"\"\"The running average of a specific predicted value, i.e., the average\ncomputed over the most recent :attr:`queue_size` values.\n\nRunning average is a :class:`~texar.torch.run.metric.StreamingMetric`,\nrequires only predicted values. Running average values are unbounded\n:class:`float` numbers. By default, lower values are better, but the\nbehavior can be configured.\n\nKeyword Args:\nqueue_size (int): Size of the queue to keep history values. The running\naverage is computed over the most recent :attr:`queue_size` values.\npred_name (str): Name of the predicted value. This will be used as the\nkey to the dictionary returned by the model. Defaults to ``\"loss\"``.\nhigher_is_better (bool, optional): If specified, the\n:attr:`higher_is_better` attribute for the instance is overwritten\nby the specified value.\n\"\"\"\nhigher_is_better = False\nrequires_label = False\n\nhistory: Deque[float]\nsum: float\n\ndef __init__(self, queue_size: int, *, pred_name: str = \"loss\",\nhigher_is_better: bool = False):\nsuper().__init__(pred_name=pred_name, higher_is_better=higher_is_better)\nif not isinstance(queue_size, int) or queue_size <= 0:\nraise ValueError(\"'queue_size' must be a position integer\")\nself.queue_size = queue_size\n\ndef reset(self) -> None:\nsuper().reset()\nself.sum = 0.0\nself.history = deque()\n\ndef add(self, predicted: Sequence[float], _) -> None:\nif len(predicted) >= self.queue_size:\nself.history = deque(predicted[-self.queue_size:])\nself.sum = sum(self.history)\nelse:\nfor _ in range(len(predicted) -\n(self.queue_size - len(self.history))):\nself.sum -= self.history.popleft()\nself.sum += sum(predicted)\nself.history.extend(predicted)\n\ndef value(self) -> float:\nif len(self.history) == 0:\nreturn 0.0\nreturn self.sum / len(self.history)\n\n[docs]class LR(StreamingMetric[Any, float]):\nr\"\"\"The learning rate (LR) of the given optimizer. This is not exactly a\nmetric, but rather a convenience object to print learning rates in log.\n\nLR is a :class:`~texar.torch.run.metric.StreamingMetric`, requires neither\npredicted values nor labels. LR values are unbounded :class:`float` numbers,\nwith no clear definition of \"better\". Comparison of two learning rates are\nnot meaningful.\n\nKeyword Args:\noptimizer: The optimizer instance.\nparam_group (int, optional): Index of the parameter group to obtain the\nlearning rate from. Defaults to 0. You don't need to specify this if\nthe optimizer contains only one parameter group (e.g., constructed\nusing :python:`optim_class(model.parameters())`.\n\"\"\"\n\nrequires_pred = False\nrequires_label = False\n\ndef __init__(self, optimizer: Optimizer, param_group: int = 0):\nsuper().__init__(pred_name=None)\nself.optimizer = weakref.ref(optimizer)\nself.group = param_group\n\npass\n\ndef value(self) -> float:\nreturn self.optimizer().param_groups[self.group]['lr'] # type: ignore\n\ndef better(self, cur: float, prev: float) -> Optional[bool]:\n# pylint: disable=unused-argument\n# Always return `None` to indicate values are uncomparable.\nreturn None\n\ndef __getstate__(self):\n# There's no point in pickling an `LR` metric; just ignore it.\nreturn None\n\ndef __getnewargs__(self):\n# But when unpickling, we need to make sure we can construct something.\n# This requires passing a dummy `optimizer` to which a weakref can be\n# constructed. In this case, we use an arbitrary built-in class.\nreturn (int,)\n```"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.51193094,"math_prob":0.8313412,"size":5702,"snap":"2020-45-2020-50","text_gpt3_token_len":1389,"char_repetition_ratio":0.13180064,"word_repetition_ratio":0.21798365,"special_character_ratio":0.2569274,"punctuation_ratio":0.23258004,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9740546,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-10-25T07:57:44Z\",\"WARC-Record-ID\":\"<urn:uuid:c89c5399-b70c-441d-89e2-7e97957cc0ac>\",\"Content-Length\":\"75808\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:b9052407-1749-4403-a13c-4f5383e49ab8>\",\"WARC-Concurrent-To\":\"<urn:uuid:66188171-3111-492b-b100-844b0a09fcc5>\",\"WARC-IP-Address\":\"104.17.33.82\",\"WARC-Target-URI\":\"https://texar-pytorch.readthedocs.io/en/latest/_modules/texar/torch/run/metric/summary.html\",\"WARC-Payload-Digest\":\"sha1:RYFB3NRVPLOO5PIUW6VPFWFACWFRDWJX\",\"WARC-Block-Digest\":\"sha1:2HYJQRBZRCJYUOE3TYDZJ5VRB72ZZK3C\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-45/CC-MAIN-2020-45_segments_1603107888402.81_warc_CC-MAIN-20201025070924-20201025100924-00272.warc.gz\"}"} |
https://asmedc.silverchair.com/vibrationacoustics/article-abstract/108/3/362/418462/On-Statistical-Analysis-of-Gear-Dynamic-Loads?searchresult=1 | [
"Statistical analysis of the gear dynamic load is carried out using piecewise constant mesh stiffness approximation. The dynamics of the spur gear system is modeled as a nonlinear, nonstationary process, and the gear transmission error which acts as a random input to the gear system is generated by passing a Gaussian white noise process through a time invariant shaping filter. The equivalent discrete time state equation and the mean and covariance propagation equations are then written for the augmented system. Then starting from known initial conditions these propagation equations are used to compute the statistics of the steady state response and hence those of the dynamic load. A procedure is presented for the selection of proper initial conditions so as to reach the steady state condition faster, thereby reducing the computational time required. The variations in the statistics of the dynamic load with respect to changes in contact position, random error magnitude, and operating speed are also investigated with the help of a numerical example. The results show that the approach presented in this study provides truer results than the statistical linearization approach used by Tobe et al. . Moreover, the proposed procedure has the advantage that it can be applied to higher-order systems with complex mesh stiffness and torque fluctuations and to systems with symmetrical or nonsymmetrical nonlinearities.\n\nThis content is only available via PDF.\nYou do not currently have access to this content."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.83485633,"math_prob":0.927875,"size":3991,"snap":"2022-40-2023-06","text_gpt3_token_len":946,"char_repetition_ratio":0.09982443,"word_repetition_ratio":0.15745394,"special_character_ratio":0.22074668,"punctuation_ratio":0.16644114,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.96064955,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-10-03T21:19:00Z\",\"WARC-Record-ID\":\"<urn:uuid:a7cb3e62-fc30-47b1-93f6-8e0f9233a178>\",\"Content-Length\":\"112661\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:6fd9357a-7a5f-4310-b146-28ce00c8d58b>\",\"WARC-Concurrent-To\":\"<urn:uuid:53f2e7c8-3fac-4214-9079-8a40f38c342c>\",\"WARC-IP-Address\":\"52.179.114.94\",\"WARC-Target-URI\":\"https://asmedc.silverchair.com/vibrationacoustics/article-abstract/108/3/362/418462/On-Statistical-Analysis-of-Gear-Dynamic-Loads?searchresult=1\",\"WARC-Payload-Digest\":\"sha1:SMJQRXM73QOTPRVJRRL3F2SFOUXMNX6M\",\"WARC-Block-Digest\":\"sha1:5VRWON2CPI34M57HKCH4MZGSLGW6SURX\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-40/CC-MAIN-2022-40_segments_1664030337432.78_warc_CC-MAIN-20221003200326-20221003230326-00028.warc.gz\"}"} |
http://downloads.hindawi.com/journals/mpe/2015/109325.xml | [
"MPE Mathematical Problems in Engineering 1563-5147 1024-123X Hindawi Publishing Corporation 10.1155/2015/109325 109325 Research Article On Two-Level State-Dependent Routing Polling Systems with Mixed Service Zheng Guan 1 Zhijun Yang 2 Wenhua Qian 1 Min He 1 Liu Ruihua 1 School of Information Science and Technology Yunnan University Kunming 650091 China ynu.edu.cn 2 Educational and Scientific Institute Educational Department of Yunnan Province Kunming 650223 China 2015 18102015 2015 19 03 2015 01 09 2015 18102015 2015 Copyright © 2015 Guan Zheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.\n\nBased on priority differentiation and efficiency of the system, we consider an N+1 queues’ single-server two-level polling system which consists of one key queue and N normal queues. The novel contribution of the present paper is that we consider that the server just polls active queues with customers waiting in the queue. Furthermore, key queue is served with exhaustive service and normal queues are served with 1-limited service in a parallel scheduling. For this model, we derive an expression for the probability generating function of the joint queue length distribution at polling epochs. Based on these results, we derive the explicit closed-form expressions for the mean waiting time. Numerical examples demonstrate that theoretical and simulation results are identical and the new system is efficient both at key queue and normal queues.\n\n1. Introduction\n\nIn this paper, we study a class of N+1 queues’ polling systems that consists of one key queue, Qh, and N normal queues, Q1,Q2,,QN, which are attended by a single server. Studies on the polling systems have attracted extensive attentions in the last years due to their vast area of applications in communication network, production, and transportation. Excellent surveys on polling systems analysis and their applications may be found in . However, many studies in the literatures assume that the server visit the queues in a fixed, cyclic order. This might not be a realistic assumption, as queues might have different priority level; queues with high priority should be visit more frequently than the lower ones; sometime queues might be empty and then there is no need to visit. As such, we study the case where the server just visits active queues with customers. Note that as a consequence, after skipping the empty queues, server could provide more visit opportunity to active queues with customers. Furthermore, parallel process of service period and switch-over period allows a successive service between two active queues without the duration of switch-over time. To provide priority differentiation service, queues are separated as one key queue and N normal queues. Two-level route order and mixed service scheme are used to provide high priority to key queue.\n\nIt is observed that in the wide body of literature on polling system hardly can any studies be found that take the consideration of queue state-dependent routing and service priority simultaneously. The reason for this may lie in the fact that the analysis of state-dependent routing polling model is much more complex than that of cyclic polling model, especially in priority differentiated model. In particular, waiting time and queue length analysis of two-level priorities polling systems can be found in , in which the server visits queues in a two-level route; that is, the server polls key queue with exhaustive scheme after each gated service to normal queue . This work is extended in with assigning 1-limited service discipline to normal queues. More recently, Yang et al. set the exhaustive service for normal queue and gated service for key queue to ensure fairness but just acquire the first moment performance of the system as mean queue length at the polling epoch and the mean cyclic time . The parallel discipline is used to improve the delay performance in , in which when the current polling queue has customers in storage the server will process service while switching to the successive queue simultaneously and begins to serve the successor once it finishes the service of the current one. This scheme could improve polling efficiency in high traffic cases. However, the parallel mechanism will be invalid when there is no customer in the queue. In low traffic cases, useless polling to idle queue becomes an obvious liability in cyclic polling model. Routing depends on the event whether a queue is empty or it is not helpful to this problem . In this paper, we consider the special setting to a two-level mixed service polling model, where the key queue is served exhaustively while normal queues are served in 1-limited mechanism. Furthermore, the server no longer checks all the stations in a fixed order; only active stations with transfer requirements could be served and then the switch-over period and service period are processed paralleled. This mechanism increases the system utilization and reduces the mean waiting time.\n\nAlthough the exhaustive service discipline in principle fits the branching property, the present model involves 1-limited service discipline, which does not satisfy the above-mentioned branching property. The explicit analysis of nonbranching service disciplines is mostly in special setting, such as [10, 11] studied on two-queue polling systems and studied on symmetric 1-limited model. In this paper, we follow the special setting in and analyze the mean waiting time of the present model under the assumption on the symmetrical characteristic among normal queues, as will be described in greater detail in Section 2.\n\nInitially, we follow an approach similar to the analysis of , which uses a recursive iteration of a functional equation, for the probability generating function (PGF) of the joint queue-length distribution at moments the server starts a visit period.\n\nThe main contributions of this paper can be summarized as follows. Firstly, we extend the parallel two-level poling system in by using queue state-dependent routing, in which only active queues with customers could be visited by server. This scheme is helpful to avoid the consumptions induced by idle visit. Secondly, under the assumption of a stable system, we obtain the explicit expressions for the PGF for the joint queue length distribution at polling epochs as a starting point of key queue and normal queue separately. Thirdly, we achieve the exact closed-form expression of the mean waiting time under the assumption on the symmetrical characteristic of normal queue.\n\nThe rest of the paper is structured as follows. In Section 2, we give a formal description of the polling model that we study and we introduce the necessary notation. Based on this, in Section 3, we derive the expressions for the mean waiting time of the present model under the assumption of a semisymmetric (symmetrical characteristic of normal queue) stable system, by taking a functional equation for the PGF for the joint queue length distribution at polling epochs as a starting point. In Section 4, numerical results obtained with the proposed analytical models are shown and their very good agreement with realistic simulation results is discussed. Finally, concluding remarks and directions for future research are given in the end.\n\n2. Model Description\n\nConsider a discrete time (timeline is divided into time slot) polling system consisting of N (N2) infinite-buffer queues Q1,Q2,,QN, and Qh. The single server visits active queues in a two-level state-dependent routing order and serves the customers with mixed service discipline.\n\nIn the arrival process, type-j (j=1,2,,N,h) customers arrive at Qj according to an independent Poisson arrival process. The generating function of arrival process in queue j is Aj(zj), with the variance of σλj2=Aj1+λj-λj2 and the arrival rate of λj=Aj1. The total arrival rate is i=1Nλi+λh.\n\nIn the service process, we assume that customers in queue j (j=1,2,,N,h) receive individual service. The service time of a customer at each queue is independent of each other. Their generating function is Bj(zj), with the variance of σβj2=Bj1+βj-βj2 and the mean value βj=Bj1. We propose a two-level server routing make the high priority queue be visited more frequently than others and add mix-service discipline to ensure the high priority of Qh. The load offered to Qj is ρj=λjβj, and the total offered load is equal to i=1Nρi+ρh.\n\nState-Dependent Routing. Queues are partitioned as active queue and idle queue by their buffer condition. Only active queues with customers waiting in the buffer could be visited by the server in order. Idle queue with empty buffer would be skipped in the current polling round.\n\nTwo-Level Polling. The server visits queues governed by a two-level routing. In the first polling level, the server polls between the high priority queue Qh and an active normal queue; in the second level, for each time after the exhaustive service at Qh, one normal active queue is visited in a cyclic order; that is, the server routing in this model is 1hihi+1hN.\n\nIn the switch-over process, a parallel mechanism is used. When the server polls an active queue at time with customers in its buffer, the server will provide service and inquire the next active queue simultaneously and then switch to serve the successor immediately without the switch-over time once it has finished the current service. Combined with the state-dependent routing scheme, over the course of a visit period, the server serves the active queues and normal queue in sequence continuously until the entire system is empty; there will be no consumption of switch-over time anymore in the present model. More especially, we assume the server consume one time slot to confirm the system state when the system is entirely empty.\n\nMix-Service Discipline. Exhaustive discipline is specified for the key queue and 1-limited discipline for normal queues, so that the entire customers in the key queue could be served in the present server round, while those who are in normal queues might need several rounds when there are more than one customer in the buffer. Let Fh denote the duration of a service period for the customers arrive during arbitrary time slot in Qh. This service period consists of the services of its ancestral customers arriving during the exact slot and the services of the offspring line of the ancestral customers . The generating function of Fh is denoted by Fh(zh)=E[zhFh]. Such a functional equation has already been derived in as Fh(zh)=Ah(Bh(zhF(zh))).\n\nIn the remainder of this paper, we are interested in the queue length distributions at the polling epoch of Qi and Qh. Let ξj(n) denote the number of customers present at Qj at tn when the server starts a visit period at Qi, and let ξj(n) denote the number of customers present at Qj at tn when the server starts a visit period at Qh successively with the service of Qi. The joint distribution of ξj(n+1) and ξj(n) is represented by the N-dimensional PGF Gi+1(z1,,zN,zh) and Gih(z1,,zN,zh).\n\nWe analyze the system under stability conditions (i=1Nρi+ρh<1) . Normal queues in the present model are served in a 1-limited manner, which does not satisfy the well-known branching property in polling systems. Therefore, more specifically, in the analyses of mean waiting time, we assume the normal queues are symmetric; that is, normal queues have the same customer arrival rate and service rate.\n\nIn this section, we derive explicit expression for the joint queue length distribution. In Section 3.1, we first obtain expressions for Gi+1(z1,,zN,zh) and Gih(z1,,zN,zh), the joint queue length PGF at the polling epoch at Qi+1 and Qh. These results ultimately lead in Section 3.2 to the first and second moment of the PGF, and obtain the expressions for E[Wi] and E[Wh], the mean waiting time of type-i and type-h customers that arrive at an arbitrary point in time.\n\n3.1. Joint Queue Length Distribution at Polling Epoch\n\nAssuming that the server begin the service of Qi at tn, define a random variable ξj(n) as the number of type-j (j=1,2,,N,h) customers at time tn. Then the status of the entire polling model at time tn can be represented as {ξ1(n),,ξN(n),ξh(n)}. Denote ξj(n+k) as the number of type-j customers at tn+k, the polling epoch of Qi+k. The status of the entire polling model at time tn+k can be represented as {ξ1(n+k),,ξN(n+k),ξh(n+k)} while ξi(n) is the number of type-j customers in at time tn, at which the server begins providing service to Qh and the status of the entire polling model at time tn can be represented as {ξ1(n),,ξN(n),ξh(n)}. Under the necessary and sufficient condition for the stability of the system i=1Nρi+ρh<1, the probability distribution is defined as(1)limnPξjn=xj;j=1,,N,h=πix1,,xN,xh,limnpξjn=yj;j=1,,N,h=πihy1,,yN,yh.The generating functions at tn and tn are(2)Giz1,,zN,zh=x1=0xN=0xh=0z1x1zNxnzhxhπix1,,xN,xhi=1,2,,N,Gihz1,,zN,zh=y1=0yN=0yh=0z1y1zNynzhyhπihy1,,yN,yhi=1,2,,N.\n\nAccording to the proposed mechanism, the system variables have the following equations. When the server begins the service on Qi+1 at tn+1, we have(3)ξjn+1=ξjn+ηjνhjh0j=h.vj(n) is the service time in Qj and ηk(vj) is the number of arrivals to Qk during vj(n).\n\nThe server just finishes the service of Qh in an exhaustive manner and starts the polling on Qi+1 at tn+1. Such a functional equation of exhaustive service has already been derived in . Applying these results to our case, we obtain(4)Gi+1z1,z2,,zN,zh=limnEj=1Nzjξin+1zhξhn+1=Gihz1,z2,,zN,Bhj=1NAjzjFhj=1NAjzj.\n\nThe expression can be interpreted as follows. At the start of the visit period at Qi+1, type-i customers are those at the polling epoch of Qh plus the new customers arriving at each queue during the service period of the Qh in exhaustive scheme, and no type-h customer resumes at that moment.\n\nWhen the server begins the service on Qh at tn, we have(5)ξjn=ξjn+ηjνi,jih,ξin+ηiνi-1,j=iξin0,ηjνi,j=h,ξjn=ξjn,jih,0,j=iξin=0,0,j=hνj(n) is the service time in Qj, and ηk(νj) is the number of arrivals to Qk during νj(n).\n\nIn our case, for normal queues, the server just polls the active queues with customers in parallel 1-limited manner. To gain more insight in the state-dependent service discipline, let Pi denote the queue length at the service epoch in an M/G/1 queue with the same arrival process and service-time distribution as Qi. We assume that the k customers have waited in Qi at the start of the busy period with probability pk[0,1), k=0pk=1. Then we can acquire the queue length generating function at the service epoch as Pizi=Aizik=0pkzik, where Ai(zi) is the PGF of the arrival process as defined in Section 2. Specifically, the server does not provide service when the queue length is zero, so we assume that k customers resumed after the end of the busy time in 1-limited service with the probability of pk[0,1), and pk=pk+1 for k=0,1,. Consequently, the probability space could be rebuilt as(6)Pizi=BiAiziAizip0+k=0pkzik=BiAizik=0pkzik-p0zi0zi+p0zi0.\n\nWith the definition of Pi(zi), we have(7)Pizi=BiAiziPizi-Pizizi=0zi+Pizizi=0.Applying these results to our case, we obtain(8)Gihz1,,zN,zh=limnEj=1Nzjξinzhξhn=1ziBij=1NAjzjAhzhGiz1,,zN,zh-Giz1,,zN,zhzi=0+Giz1,,zN,zhzi=0-Giz1,,zN,zhz1,,zN,zh=0+j=1NAjzjAhzhGiz1,,zN,zhz1,,zN,zh=0.\n\nThe expression can be interpreted as follows. At the start of the visit period at Qh, in the case that the former Qi is active, one type-i customer would have been served at tn and new customers arrived at each queue during the service period of the exact type-i customer. The server would skip Qi to Qi+1 when Qi is empty; in that case, the distribution of the number of customers in the systems is represented by the generating function Giz1,,zi,,zN-1,zhzi=0, with the exception as the system is entirely empty, which is represented by the generating function Giz1,,zi,,zN-1,zhz1,,zN-1,zh=0. When the system is entirely empty, the server will stop providing service for one time slot until new customers arrive during this time slot, and this number of customers is represented by the last partition of the addition formula.\n\n3.2. Expression for the Mean Waiting Time\n\nNow we have derived expressions for the PGF Gi+1z1,,zi,,zN,zh and Gihz1,,zi,,zN,zh pertaining to the queue length at polling epoch of Qi+1 and Qh, we use these results to obtain E[Wi], the mean waiting time of type-i normal customers, and E[Wh], the mean waiting time of type-h high priority customers.\n\n3.2.1. The First and Second Moment of <inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M146\"><mml:msub><mml:mrow><mml:mi>G</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mfenced separators=\"|\"><mml:mrow><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant=\"normal\">1</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:mo>…</mml:mo><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:mo>…</mml:mo><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mi>N</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mi>h</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfenced></mml:math></inline-formula> and <inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M147\"><mml:msub><mml:mrow><mml:mi>G</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi><mml:mi>h</mml:mi></mml:mrow></mml:msub><mml:mfenced separators=\"|\"><mml:mrow><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant=\"normal\">1</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:mo>…</mml:mo><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:mo>…</mml:mo><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mi>N</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mrow><mml:mi>z</mml:mi></mml:mrow><mml:mrow><mml:mi>h</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfenced></mml:math></inline-formula>\n\nTo start the analysis of mean waiting time of type-j customers, we need to calculate the generating functions and its derivation at the point z=1, z is the abbreviation of the (1×N+1) vector of (z1,,zi,,zN,zh), and 1 is the (1×N+1) vector with 1.\n\nG i + 1 ( z ) is the PGF of the joint queue length at the polling epoch of Qi, so we have(9)Giz1,,zi,,zN,zh=x1=0xi=0xN=0xh=0z1x1zixizNxnzhxhPξ1n=x1,,ξin=xi,,ξNn=xN,ξhn=xh=x1=0xi=0xN=0xh=0z1x1zixizNxnzhxhPξ1n=x1,,ξNn=xN,ξhn=xhξin=xiPξin=xi.\n\nTaking the kth derivative with respect to zi yields(10)kGiz1,z2,,zi,,zN,zhzik=x1=0xN=0xh=0z1x1zixi-kzNxNzhxhxi!xi-k!Pξ1n=x1,,ξNn=xN,ξhn=xhξin=xiPξin=xi.\n\nSetting zi=0 yields(11)kGiz1,z2,,zi,,zN,zhzikzi=0=x1=0xN=0xh=0z1x11zNxNzhxhk!Pξ1n=x1,,ξNn=xN,ξhn=xhξin=kPξin=k=k!Pξin=kx1=0xN=0xh=0z1x11zNxNzhxhPξ1n=x1,,ξNn=xN,ξhn=xhξin=k=k!Pξin=kEz1ξ1n1zNξNnzhξhnξin=k.Rearranging terms and setting k=0, we have(12)Giz1,z2,,zi,,zN,zhzi=0=Pξin=0Ez1ξ1n1zNξNnzhξhnξin=0,Gi1i=Pξin=0.Extending this result we have(13)Gi0=Pξ1n=0,,ξin=0,,ξNn=0,ξhn=0.0 is the (1×N+1) vector with 0, and 1j is the (1×N+1) vector with 0 in jth position and 1 in all other entries.\n\nDefine the first derivative of Gi(z) and Gih(z) at z=1 as (14)gij=limz1,,zi,,zN,zh1Gizzj,gihj=limz1,,zi,,zN,zh1Gihzzj,j,k=1,2,,N,h.(15)gihj=βiλj1-Gi1i+gij+λjGi0(16)gihi=βiλi-11-Gi1i+gii+λiGi0(17)gihh=βiλh1-Gi1i+λhGi0(18)gi+1i=gihi+gihhβhλi1+Fh1(19)gi+1j=gihj+gihhβhλj1+Fh1.Calculate j=1Ngj+1k yields(20)1-Gi1i=NλiGi01-ρh-Nρ.Define the second derivative of Gi(z) and Gih(z) at z=1 as(21)gij,k=limz1,,zi,,zN,zh12Gizzjzkgi0j,k=limz1,,zi-1,zi+1,,zN,zh12Gizzi=0zjzkgi00j,k=limz1,,zN,zh02Gizz1,,zN,zh=0zjzkgihj,k=limz1,,zN,zh12Gihzzjzki=1,2,,Nj,k=1,2,,N,h.\n\nSubstitute (4) and (8) into the above second derivative formulas.\n\nWe assume the N normal queues are symmetrical; that is, λi=λ, βi=β, i=1,2,,N. Then simplifying these we get the second derivative of Gi(z) and Gih(z) at z=1 as follows:(22)gihh,h=B1λh21-Gi1i+βAh11-Gi1i+Ah1Gi0.(23)gii=1-Gi1i211-ρh-Nρ1-ρhρhA1λ1-ρh2+Ahβh2+λhBh+NB1λ2+NβA1+λ1-ρh+λhλBh11-ρh-Nρ+1-Gi1i.\n\nRemark 1.\n\nThough gi(i) is the first derivative at z=1Gi(z) in definition, it is clear that it contains the second moment parameter as Aj(1) and Bj(1). So, gi(i) is a second moment parameter for the system performance.\n\n3.2.2. Analysis of <inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M197\"><mml:mi>E</mml:mi><mml:mo stretchy=\"false\">[</mml:mo><mml:msub><mml:mrow><mml:mi>W</mml:mi></mml:mrow><mml:mrow><mml:mi>h</mml:mi></mml:mrow></mml:msub><mml:mo stretchy=\"false\">]</mml:mo></mml:math></inline-formula> and <inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M198\"><mml:mi>E</mml:mi><mml:mo stretchy=\"false\">[</mml:mo><mml:msub><mml:mrow><mml:mi>W</mml:mi></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo stretchy=\"false\">]</mml:mo></mml:math></inline-formula>\n\nDefine Wh and Wi as the waiting time of type-h and type-i customers, which denotes the time from the epoch when a customer arrives at the queue to the time it is served. In the present model, high priority type-h customers are served in the exhaustive service and normal type-i customers are served in 1-limited service. Based on the related research works in , the mean waiting time of type-h customers E[Wh] and the type-i customers E[Wi] can be calculated as follows:(24)EWh=gihh,h2λhgihh-Ah12λh21+ρh+λhBh121-ρh,(25)EWi=1λ1-Gi1igii-1λ-A12λ2.\n\nTaking (17), (22) in (24) in the above expressions, we have(26)EWh=121-ρh1-ρh+NλB1+λhBh1-12λh21+ρhAh1.\n\nTaking (17), (22), and (23) in (25) in the above expressions, we have(27)EWi=12λ11-ρh-Nρ1-ρhρhA1λi1-ρh2+Ahβh2+λhBh+NB1λ2+NβA1+λ1-ρh+λhλBh11-ρh-Nρ-A12λ2.\n\n4. Numerical Study\n\nIn this section we study the accuracy of the theoretical analysis and compare the mean waiting time of the present model with two existing two-level polling models. Consider an N+1 queues’ model with one high priority queue Qh and N normal queues Qi (i=1,,N) defined as follows: the service times of all customers are exponentially distributed with mean β in Qi and βh in Qh. The arrival processes are Poisson process with rate λ in Qi and λh in Qh. The relative parameter values are listed in Table 1, in which {a:k:b} means the parameter is varied between a and b in steps of k.\n\nTest bed used to compare the mean waiting time.\n\n Parameter Number of normal queues Arrival rate Service time Switch over time Notation value N λ λ h β β h γ Figure 1(a) 1 : 1 : 9 0.04 0.1 2 2 Figure 1(b) 4 0.02 0.1 : 0.05 : 0.4 1 2 — Figure 1(c) 4 0.02 : 0.02 : 0.18 0.1 1 2 — Figure 1(d) 4 0.02 0.1 2 1 : 1 : 9 — Figure 1(e) 4 0.02 0.1 1 : 1 : 10 2 — Figure 2 4 0.01 : 0.01 : 0.09 0.1 2 2 1\n\nFrom Figure 1, we can clearly see that, firstly, the theoretical value and the simulation result coincided with each other. Secondly, when the total offered load grew with the arrival rate, service time, and the number of queues, with the mean waiting time increasing distinctly in Qi, while the performances in Qh are much better, both queue and mean waiting time are much lower than normal queues, and the growth in Qh with the total offered load presents much more smoothly.\n\nTheoretical and simulation values of E[Wh] and E[Wi] from different values of the load increasing with the increasing of the number of normal queues. (a) is the total offered load increasing with the growth of the number of normal queues. (b) is the total offered load increasing with the growth of the arrival rate of Qh. (c) is the total offered load increasing with the growth of the arrival rate of Qi. (d) is the total offered load increasing with the growth of the service time of Qh. (e) is the total offered load increasing with the growth of the service time of Qi.\n\nIt is worth considering whether the state-dependent mechanism improves the performance of the system comparing with the existing two-level polling systems. In order to answer this question, we compare a classical two-level system with switch-over time , abbreviated as classical system and a parallel two-level system , abbreviated as parallel system in Figure 2. The service discipline in the comparisons is 1-limited service for normal queues and exhaustive service for the key queue. Overall models have the same test bed as shown in Table 1. We just vary the working mechanism.\n\nComparing of mean waiting time among the classical two-level system , the parallel two-level system , and the state-dependent two-level system. (a) is the theoretical value comparison of E[Wi] with the growth of the arrival rate in Qi. (b) is the theoretical value comparison of E[Wh] with the growth of the arrival rate in Qi.\n\nFigure 2 shows the mean waiting time of normal queues in (a) and mean waiting time of key queue in (b). Comparing with the forgoing, the state-dependent system achieves a better performance in delay guarantee and stability. It is clear in Figure 2(a), for lower load, in most of the cases, that there is no customer in the buffers; thus a switch-over time is necessary when the server switches between Qi and Qh in the classical and parallel system, while the empty queues would be skipped in the present model. Therefore, customers in the state-dependent system achieve a lower mean waiting time, which is under 20% of the forgoing. In the heavy traffic, the server could not provide service in the necessary switch-over time for the classical system; consequently, it becomes unstable when the arrival rate of Qi grows over 0.06 in this case. The parallel system and the state-dependent system have better performance in system stability; especially in state-dependent system, the mean waiting time of the normal customers has less than 50% of which in the parallel system. A conclusion can be drawn from a comparison between Figures 2(a) and 2(b), which is that for all three two-level models the mean waiting time of the customers in key queue is significantly lower than that in normal queues, and as illustrated in Figure 2(b), the mean waiting time for h-type customers in state-dependent system is lower than that of the others.\n\n5. Conclusion\n\nWhen comparing the model of the present paper with the existing literature, the contribution of the present paper is twofold. One of the most striking differences is the queues which are partitioned as active queue and idle queue by their buffer condition, and only active queues with customers waiting in the buffer could be visited by the server in a two-level order. As illustrated in the numerical example, both i-type customers in normal queues and h-type customers in key queue acquire better delay performance than those in systems without queue-stated differentiation. Another notable contribution of the paper is that we achieve the closed-form exact expressions of the mean waiting time for customers in normal queues and key queue, under the assumption of the symmetric of normal queues. The total unknowns in these equations are all first moments of random variables and, thus, no correlation terms are required.\n\nConflict of Interests\n\nThe authors declare that there is no conflict of interests regarding the publication of this paper.\n\nAcknowledgments\n\nThis work was supported by a Grant from the National Science Foundation of China (nos. 61463051 and 61463054), the National Science Foundation of Yunnan Province (no. 2012FD002), and the Science Foundation of Yunnan Provincial Department (no. 2014Z010).\n\nTakagi H. Analysis of polling systems Performance Evaluation 1985 5 3 206 Levy H. Sidi M. Polling systems: applications, modeling, and optimization IEEE Transactions on Communications 1990 38 10 1750 1760 10.1109/26.61446 2-s2.0-0025502587 Boon M. A. A. van der Mei R. D. Winands E. M. M. Applications of polling systems Surveys in Operations Research and Management Science 2011 16 2 67 82 10.1016/j.sorms.2011.01.001 2-s2.0-79957844270 Vishnevskii V. M. Semenova O. M. Mathematical models to study the polling systems Automation and Remote Control 2006 67 2 173 220 Yang Z.-J. Zhao D.-F. Ding H.-W. Zhao Y.-F. Research on two-class priority based polling system Acta Electronica Sinica 2009 37 7 1452 1456 2-s2.0-69249127140 Liu Q. Zhao D. Zhou D. An analytic model for enhancing IEEE 802.11 point coordination function media access control protocol European Transactions on Telecommunications 2011 22 6 332 338 10.1002/ett.1482 2-s2.0-81355138818 Yang Z.-J. Ding H.-W. Chen C.-L. Research on E(x) characteristics of two-class polling system of exhaustive-gated service Tien Tzu Hsueh Pao/Acta Electronica Sinica 2014 42 4 774 778 10.3969/j.issn.0372-2112.2014.04.023 2-s2.0-84904046560 Guan Z. Zhao D. Zhao Y. A discrete time two-level mixed service parallel polling model Journal of Electronics 2012 29 1-2 103 110 10.1007/s11767-012-0781-3 2-s2.0-84861976713 Dorsman J. P. Boxma O. J. van der Mei R. D. On two-queue Markovian polling systems with exhaustive service Queueing Systems 2014 78 4 287 311 10.1007/s11134-014-9413-y MR3269260 2-s2.0-84910150691 Boon M. A. Adan I. J. Boxma O. J. A two-queue polling model with two priority levels in the first queue Discrete Event Dynamic Systems 2010 20 4 511 536 10.1007/s10626-009-0072-9 MR2721286 2-s2.0-77956790267 Dongfeng Z. Bihai L. sumin Z. Study of a polling systems with limited service Journal of Electronics 1997 19 1 44 49 Ibe O. C. Cheng X. Stability conditions for multi-queue systems with cyclic service IEEE Transactions on Automatic Control 1988 33 1 102 103 10.1109/9.370 2-s2.0-0023842924 Boxma O. J. Groenendijk W. P. Pseudoconservation laws in cyclic-service systems Journal of Applied Probability 1987 24 4 949 964 10.2307/3214218 MR913834 Zhao D. Zheng S. Analysis on a polling model with exhaustive service Acta Electronica Sinica 1994 22 5 102 107 2-s2.0-0028422934"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.90160745,"math_prob":0.884889,"size":4030,"snap":"2019-43-2019-47","text_gpt3_token_len":850,"char_repetition_ratio":0.12468952,"word_repetition_ratio":0.07196402,"special_character_ratio":0.2191067,"punctuation_ratio":0.07032349,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9589004,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-11-18T13:51:14Z\",\"WARC-Record-ID\":\"<urn:uuid:9ed1eaa5-3f0b-403a-b7f4-52d8e5f0c072>\",\"Content-Length\":\"235499\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:a528b2e7-c4c1-4867-8c5b-7e69d77a8557>\",\"WARC-Concurrent-To\":\"<urn:uuid:1e7e46b7-48d0-4d36-80b0-8d92fabcd87c>\",\"WARC-IP-Address\":\"52.216.130.3\",\"WARC-Target-URI\":\"http://downloads.hindawi.com/journals/mpe/2015/109325.xml\",\"WARC-Payload-Digest\":\"sha1:HYJOAI5SJL2L5RBIL6GRGNVRYJT7ZT7X\",\"WARC-Block-Digest\":\"sha1:QRPMM5636FJFUDJZYDKZEDBB5HWGL3P3\",\"WARC-Identified-Payload-Type\":\"application/xml\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-47/CC-MAIN-2019-47_segments_1573496669795.59_warc_CC-MAIN-20191118131311-20191118155311-00406.warc.gz\"}"} |
https://communities.sas.com/t5/SAS-Procedures/Adjust-simulate-how-does-it-adjust/td-p/301201 | [
"Hi, I am trying to understand what adjust=simulate does (within the lsmestimate option in proc mixed and other procs, SAS 9.4). I am comfortable with what it is doing at a high level, but I can not get my head around how it does it. I have read the reference below and the on line help in SAS (also below) but I am finding it hard to grasp the principle of how the the adjustment is done. I believe simulations are done and the contrasts are calculated for the specified contrasts for each simulation and a p-value is obtained from a mutivariate t but I'm unclear on how the simulations are generated and how the adjusted p-value is obtained. A simple explanation or even examples would be great. I have emailed SAS but they have no further info they can provide to me. thank you.\n\nhttp://support.sas.com/documentation/cdl/en/statug/68162/HTML/default/viewer.htm#statug_glm_details2...\n\n1 ACCEPTED SOLUTION\n\nAccepted Solutions\n\nWhat is your statistical background and previous experience with simulation methods in statistics? From your questions, it sounds like you need to start with simpler situations to better unerstand the main ideas. Try reading about using simulation to estimate the power of a statistical test and Monte Carlo methods for contingency tables in SAS.\n\nAlso what is the application here? Are you merely intellectually curious about the details of the algorithm? Or do you need to implement a similar algoithm in a different situation?\n\n3 REPLIES 3\n\nIt's basically a multivariate generalization of using simulation to estimate the coverage probability of a 1-D confidence interval.\n\nSuppose you want to estimate ONE linear combination of the betas: c`*beta. You also want a CI. The statistic c`*beta is normally distributed, so the CI will be of the form\n\nc`*beta +/- delta * stderr(c`*beta).\n\nThe challenge is to choose delta. For simple estimates (like c=(1 0 0 .. 0)), you can choose delta to be a critical value of the t distribution: delta=t(1-alpha/2, df). The t distribution is used instead of the normal distribution to adjust for the finite sample size.\n\nNow suppose that you have k linear combinations and you want SIMULTANEOUS CIs. The k estimates are jointly MVN with mean and covariance that can be computed because you are assuming a GLM. So simulate a bunch of values from the appropriate MVN distribution (actually multivariate t) and then use quantiles of the simulated distribution of estimates to find the critical value (delta) that works simultaneously for all the estimates. Make a bunch of draws of the form (t1, t2, ..., tk) and for each draw compute the statistic max(|t1|, ..., |tk|). The union of those max statistics has an empirical distribution. The Edwards/Berrry paper says that you can choose delta to be the (1-alpha)th quantile of the empirical distribution.\n\n* When you say \"simulate a bunch of values from the appropriate MVN distribution (actually multivariate t)\". Do you mean, generate a lot of datasets, say 100 to keep things simple, from a mvt which has means which match the means of your k contrasts/estimates and covariance that matches the covariance of your k contrasts/means?\n\n* Then you say \"use quantiles of the simulated distribution of estimates to find the critical value (delta) that works simultaneously for all the estimates.\". My guess at what this means is, for the each datasets you have simulated, calculate the value of each of the k contrasts, so if k=2, and 100 datasets, you have 100 values for each contrast. Then I'm not sure how you find the critical value. You mention later to use (1-alpha)th quantile. So if alpha is 5%, is the 95th ordered value from the 100 values I have for each k my critical value?\n\n*Then \"Make a bunch of draws of the form (t1, t2, ..., tk) and for each draw compute the statistic max(|t1|, ..., |tk|).\". I'm lost here, am I randomly selecting a value from the 100 values I have for each k, so in my case I would have two values, then select the max of these and build up a distribution of these I guess. Sorry, I'm not sure what happens now.\n\nWhat is your statistical background and previous experience with simulation methods in statistics? From your questions, it sounds like you need to start with simpler situations to better unerstand the main ideas. Try reading about using simulation to estimate the power of a statistical test and Monte Carlo methods for contingency tables in SAS.\n\nAlso what is the application here? Are you merely intellectually curious about the details of the algorithm? Or do you need to implement a similar algoithm in a different situation?\n\nDiscussion stats\n• 3 replies\n• 1455 views\n• 1 like\n• 2 in conversation"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9092807,"math_prob":0.9375539,"size":5414,"snap":"2023-40-2023-50","text_gpt3_token_len":1183,"char_repetition_ratio":0.12606284,"word_repetition_ratio":0.27734807,"special_character_ratio":0.22072405,"punctuation_ratio":0.11797753,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9873639,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-12-04T10:46:08Z\",\"WARC-Record-ID\":\"<urn:uuid:d3d6e280-4d55-49f3-b1d5-5893c896c69d>\",\"Content-Length\":\"208899\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:8d723028-06cd-409a-8b7f-e177f0d287ee>\",\"WARC-Concurrent-To\":\"<urn:uuid:c2d7032b-9833-4a1d-aa62-3e6a39fc5cb3>\",\"WARC-IP-Address\":\"18.67.65.90\",\"WARC-Target-URI\":\"https://communities.sas.com/t5/SAS-Procedures/Adjust-simulate-how-does-it-adjust/td-p/301201\",\"WARC-Payload-Digest\":\"sha1:5CAUWI2BXQGXQY3NOXTXGNIPNBWCENVH\",\"WARC-Block-Digest\":\"sha1:RR7ZV4LK5TZVRBDDJSS3NRQXYNJPFQD6\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-50/CC-MAIN-2023-50_segments_1700679100527.35_warc_CC-MAIN-20231204083733-20231204113733-00596.warc.gz\"}"} |
https://www.jetpunk.com/user-quizzes/19203/intro-to-motion-physics-2/stats | [
"# Statistics for Introduction to Motion Physics Quiz #2\n\n### General Stats\n\n• This quiz has been taken 655 times\n• The average score is 9 of 15\n\nEnergy associated with movementKinetic Energy\n90%\nStored EnergyPotential Energy\n89%\nMeasure of how heavy you areMass\n82%\nEnergy and the above answer are measured in __________Joules (J)\n75%\nSpeed is to scalar as Velocity is to __________Vector\n73%\nMeasure of change in energy (force times distance)Work\n67%\nEnergy present in objects that are in a position from which they could fall as a result of the force of gravityGravitational Potential Energy\n66%\nThe force applied to an object by the Earth due to gravitational attractionWeight\n63%\nNegative AccelerationDeceleration\n62%\nHow useful a system as an energy converter is [(Useful energy output over energy input) times 100%]Efficiency\n57%\nProperty that makes objects resist changes in their motionInertia\n53%\nEnergy stored within the nucleus of all atomsNuclear Energy\n49%\nEnergy present in objects or groups of objects in which positively and negatively charged particles are separated ; also present when the charges are brought togetherElectrical Potential Energy\n32%\nEnergy can never be created nor destroyed - only transferred and storedLaw of Conservation of Energy\n29%\nEnergy present in all substances as a result of the electrical forces that hold atoms together ; A form of the above type of energyChemical Potential Energy\n26%"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9113481,"math_prob":0.86968017,"size":1388,"snap":"2021-21-2021-25","text_gpt3_token_len":308,"char_repetition_ratio":0.14378613,"word_repetition_ratio":0.017316017,"special_character_ratio":0.2615274,"punctuation_ratio":0.0091743115,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9618333,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-05-06T04:44:10Z\",\"WARC-Record-ID\":\"<urn:uuid:ac9a1561-5377-4bd2-8bb5-fcc0d2bf0bab>\",\"Content-Length\":\"29424\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:14e0724e-e9fc-474c-8b1c-b16d497e22cb>\",\"WARC-Concurrent-To\":\"<urn:uuid:91e0d72d-a2d1-4729-b227-5b089b9b63dc>\",\"WARC-IP-Address\":\"34.193.34.229\",\"WARC-Target-URI\":\"https://www.jetpunk.com/user-quizzes/19203/intro-to-motion-physics-2/stats\",\"WARC-Payload-Digest\":\"sha1:NG727TJXR7CUBPV4OBFVV2FK3PXCJ45F\",\"WARC-Block-Digest\":\"sha1:UB2FQ3WN3CZV5B5IC26AGNTOMRRWIEQ5\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-21/CC-MAIN-2021-21_segments_1620243988725.79_warc_CC-MAIN-20210506023918-20210506053918-00254.warc.gz\"}"} |
https://rdrr.io/cran/rsimsum/man/nsim.html | [
"# nsim: Compute number of simulations required In rsimsum: Analysis of Simulation Studies Including Monte Carlo Error\n\n nsim R Documentation\n\n## Compute number of simulations required\n\n### Description\n\nThe function `nsim` computes the number of simulations B to perform based on the accuracy of an estimate of interest, using the following equation:\n\nB = [((Z(1 - α / 2) + Z(1 - θ)) σ) / δ] ^ 2\n\nwhere δ is the specified level of accuracy of the estimate of interest you are willing to accept (i.e. the permissible difference from the true value β), Z(1 - α / 2) is the (1 - α / 2) quantile of the standard normal distribution, Z(1 - θ) is the (1 - θ) quantile of the standard normal distribution with 1 - θ being the power to detect a specific difference from the true value as significant, and σ ^ 2] is the variance of the parameter of interest.\n\n### Usage\n\n```nsim(alpha, sigma, delta, power = 0.5)\n```\n\n### Arguments\n\n `alpha` Significance level. Must be a value between 0 and 1. `sigma` Variance for the parameter of interest. Must be greater than 0. `delta` Specified level of accuracy of the estimate of interest you are willing to accept. Must be greater than 0. `power` Power to detect a specific difference from the true value as significant. Must be a value between 0 and 1. Defaults to 0.5, e.g. a power of 50%.\n\n### Value\n\nA scalar value B representing the number of simulations to perform based on the accuracy required.\n\n### References\n\nBurton, A., Douglas G. Altman, P. Royston. et al. 2006. The design of simulation studies in medical statistics. Statistics in Medicine 25: 4279-4292 doi: 10.1002/sim.2673\n\n### Examples\n\n```# Number of simulations required to produce an estimate to within 5%\n# accuracy of the true coefficient of 0.349 with a 5% significance level,\n# assuming the variance of the estimate is 0.0166 and 50% power:\nnsim(alpha = 0.05, sigma = sqrt(0.0166), delta = 0.349 * 5 / 100, power = 0.5)\n\n# Number of simulations required to produce an estimate to within 1%\n# accuracy of the true coefficient of 0.349 with a 5% significance level,\n# assuming the variance of the estimate is 0.0166 and 50% power:\nnsim(alpha = 0.05, sigma = sqrt(0.0166), delta = 0.349 * 1 / 100, power = 0.5)\n```\n\nrsimsum documentation built on Aug. 17, 2022, 5:07 p.m."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.79356915,"math_prob":0.99409664,"size":2074,"snap":"2023-40-2023-50","text_gpt3_token_len":585,"char_repetition_ratio":0.11932367,"word_repetition_ratio":0.3298153,"special_character_ratio":0.3090646,"punctuation_ratio":0.14942528,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99908984,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-09-29T12:51:44Z\",\"WARC-Record-ID\":\"<urn:uuid:4f2922ea-3703-44e6-b47d-a31d6834d1cc>\",\"Content-Length\":\"30188\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:f9507e2f-805a-4755-9419-731e91f8ac7b>\",\"WARC-Concurrent-To\":\"<urn:uuid:f9fa33f8-1071-42c9-b5f4-f14d1514cc23>\",\"WARC-IP-Address\":\"51.81.83.12\",\"WARC-Target-URI\":\"https://rdrr.io/cran/rsimsum/man/nsim.html\",\"WARC-Payload-Digest\":\"sha1:X5QSESW6XDIAQQ7DDBFNGYHKTHJIPDOV\",\"WARC-Block-Digest\":\"sha1:3G5TNG7U6MQVH47CLI5FIN7PCDCBT4F5\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-40/CC-MAIN-2023-40_segments_1695233510516.56_warc_CC-MAIN-20230929122500-20230929152500-00324.warc.gz\"}"} |
https://www.frontiersin.org/articles/10.3389/fict.2016.00019/full | [
"World-class research. Ultimate impact.\nMore on impact ›\n\n# Frontiers in ICT",
null,
"## Original Research ARTICLE\n\nFront. ICT, 15 September 2016 | https://doi.org/10.3389/fict.2016.00019\n\n# Energetic Cost of Superadiabatic Quantum Computation\n\n• 1Instituto de Física, Universidade Federal Fluminense, Niterói, Brazil\n• 2Information Sciences Institute, University of Southern California, Marina del Rey, CA, USA\n• 3Ming Hsieh Department of Electrical Engineering, Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, CA, USA\n\nWe discuss the energetic cost of superadiabatic models of quantum computation. Specifically, we investigate the energy–time complementarity in general transitionless controlled evolutions and in shortcuts to the adiabatic quantum search over an unstructured list. We show that the additional energy resources required by superadiabaticity for arbitrary controlled evolutions can be minimized by using probabilistic dynamics, so that the optimal success probability is fixed by the choice of the evolution time. In the case of analog quantum search, we show that the superadiabatic approach induces a non-oracular counter-diabatic Hamiltonian, with the same energy–time complexity as equivalent adiabatic implementations.\n\n## 1. Introduction\n\nShortcuts to adiabatic passage (Demirplak and Rice, 2003, 2005; Berry, 2009; Torrontegui et al., 2013) provide a remarkable mechanism for speeding up quantum tasks, which can be achieved through the use of a counter-diabatic assistant driving. These techniques have been introduced to mimic the transitionless adiabatic dynamics, but with the usual constraint on the adiabatic runtime lifted. Transitionless quantum driving has been applied to a number of quantum information protocols, such as population transfer (Chen et al., 2014a; Lu et al., 2014a) and entanglement generation (Chen et al., 2014b, 2015a,b; Lu et al., 2014b). In the context of many-body systems, realizable settings have been investigated for assisted evolutions in quantum critical phenomena (del Campo et al., 2012; del Campo, 2013; Saberi et al., 2014). More recently, counter-diabatic approaches have been proposed for fast implementation of individual unitaries in quantum circuits, leading to universal superadiabatic schemes of quantum computing (QC) via local Hamiltonians (Santos and Sarandy, 2015; Santos et al., 2016). Such methods may be potentially relevant to accelerating the implementation of n-qubit controlled gates in digitized proposals of adiabatic quantum computing [see Kieferová and Wiebe (2014), Martinis and Geller (2014), Barends et al. (2015), and Hen (2015)].\n\nThe superadiabatic speedup is intrinsically connected with an increase of the energy resources demanded by the quantum computer (Santos and Sarandy, 2015; Santos et al., 2016), which in turn implies a rather versatile computational cost that is controlled by the energetic capacity available to the physical apparatus. Here, we show that this energy–time complementarity can be exploited in quantum information processing. First, we consider controlled evolutions (CE) as a mechanism to implement superadiabatic universal QC (Santos and Sarandy, 2015), which generalizes the original adiabatic approach introduced in Hen (2015). We then show that, within the superadiabatic scenario, the energetic cost can be minimized by replacing the deterministic realization of quantum gates for probabilistic implementations based on a probability distribution of a binary random variable described by an angle parameter. By doing so, the energy expense can be minimized by adjusting the probability distribution, provided the choice of the evolution time of the computational process. Second, we analyze the effects of the energy–time complementarity in analog quantum search (Grover, 1997), where the oracular approach designed by the local adiabatic Grover algorithm is known to be optimal (van Dam et al., 2001; Roland and Cerf, 2002). In this case, we show that the superadiabatic approach naturally requires an unphysical non-oracular counter-diabatic Hamiltonian, with the energy–time complexity equivalent to non-oracular adiabatic implementations.\n\nThe paper is organized as follows. In Section 2, we describe the adiabatic implementation of quantum gates via CE and several adiabatic quantum search approaches. We then provide their superadiabatic versions and introduce the metric for energetic cost used in our work. In Section 3, we investigate the energy complexity of the superadiabatic realizations of both quantum gates via CE and analog quantum search. In particular, we consider the properties of the probabilistic model of QC through CE and the consequences of the energy–time complementarity for the search problem. In Section 4, we present our conclusions and future perspectives.\n\n## 2. Materials and Methods\n\nOur aim in this Section is to discuss adiabatic implementations of QC, their superadiabatic generalizations, and the energetic cost measure adopted in this work.\n\n### 2.1. Quantum Gates by Adiabatic Controlled Evolutions\n\nLet us begin by using adiabatic CE (Hen, 2015) to implement n-controlled gates (Santos and Sarandy, 2015). To this end, we will consider the adiabatic evolution of a composite system 𝒯 𝒜 associated with a Hilbert space ℋ𝒯 ⊗ ℋ𝒜, where 𝒯 denotes a target subsystem containing n + 1 qubits and 𝒜 denotes an auxiliary subsystem containing a single qubit. We will use the first n qubits of 𝒯 as the control register of the n-controlled gate, while the last qubit will play the role of its target register. Then, a rotation of the target qubit of an angle ϕ around a direction $n^$ in the Bloch sphere will be performed when the state of the control register is |11⋯ 1⟩. We will adopt here the decimal representation |11⋯ 1⟩ ≡ |N − 1⟩, with N = 2n. An n-controlled rotation over a single qubit can be adibatically implemented by preparing the auxiliary qubit in the initial state |0⟩, with the adiabatic Hamiltonian given by (Santos and Sarandy, 2015)\n\n$H(s)=𝟙−PN−1,n−⊗H0(s)+PN−1,n−⊗Hϕ(s),$\n\nwhere $Pk,n±=|k⟩ ⟨k|⊗|n^±⟩ ⟨n^±|$ is the set of all orthogonal projectors on the subspace 𝒯 and $|n^±⟩ ⟨n^±|=1∕2(𝟙±n^⋅σ→)$, with $σ→=σx,σy,σz$. The Hamiltonians H0(s) and Hϕ(s) are given by\n\n$Hξ(s)=−ℏωσzcosθ(s)+sinθ(s)[σxcosξ+σysinξ],$\n\nwhere θ (s) = θ0s, θ0 is a constant angle, ξ = {0, ϕ}, and s denotes the normalized time s = t/τ, with τ the total evolution time. The system is prepared in the initial state |Ψ(0)⟩ = |ψn⟩ ⊗ |0⟩, where\n\n$|ψn⟩=∑m=0N−1∑ϵ=±γm,ϵ|m,n^ϵ⟩.$\n\nThen, by adiabatic evolution, the system will evolve to the final state |Ψ(1)⟩ given by\n\n$|Ψ(1)⟩=𝟙−PN−1,n^−ψn⊗|E00(1)⟩+PN−1,n^−ψn⊗|Eϕ0(1)⟩,$\n\nwhere $|Eξ0(1)⟩=cosθ0∕20+eiξsinθ0∕21$ is the ground state of Hξ(1). Then, equivalently, we can write\n\n$|Ψ(1)⟩=cosθ0∕2ψn⊗|0⟩+sinθ0∕2|ψnrot⟩⊗1,$\n\nwith\n\n$|ψnrot⟩=∑k=0N−2∑ϵ=±γk,ϵk,n^ϵ+N−1⊗[γN−1,+n^++eiϕγN−1,−n^−].$\n\nThe rotated state $|ψnrot⟩$ is the target of the n-controlled gate. However, note that |Ψ(1)⟩ in equation (5) is an entangled state. Thus, a measurement must be performed on the auxiliary system, where the action of the gate will be considered successful if 𝒜 is measured in the state |1⟩, which occurs with probability sin2 (θ0/2). On the other hand, if the outcome of a measurement on 𝒜 yields |0⟩, the adiabatic evolution should be restarted through the Hamiltonian in equation (1), as the state of the system is projected onto the initial state |Ψ(0)⟩. Naturally, by choosing θ0 = π, we deterministically ensure the success of the computation. However, as we will show, deterministic evolutions may demand more energy resources than probabilistic processes when transitionless drivings are considered. In particular, observe also that the scheme presented here allows for the implementation of arbitrary n-controlled gates, which lead to versatile sets of universal gates, e.g., single qubit rotations and controlled-NOT operations (Nielsen and Chuang, 2000).\n\nInstead of adiabatic implementations of quantum circuits, we can also consider the original approach of adiabatic QC (Farhi et al., 2001), where a single annealing process is performed using energy penalties attributed to quantum states that violate the solutions of an optimization problem. Here, we employ this method to analyze three possible adiabatic implementations of quantum search over an unstructured list. An adiabatic QC approach for the quantum search through Grover’s algorithm (Grover, 1997) was first proposed in Farhi et al. (2000) and improved by using local adiabaticity (van Dam et al., 2001; Roland and Cerf, 2002), where the adiabatic evolution is required for each local time interval, instead of being globally applied as in the original proposal. In both cases, the search for a marked element in an unstructured list of N = 2n elements (labeled by n qubits) can be achieved by employing a Hamiltonian of the form\n\n$H0(s)=f(s)(𝟙−|+⟩⟨+|)+g(s)(𝟙−|m⟩⟨m|),$\n\nwhere |m⟩ is the marked state, s is the normalized time (0 ≤ s ≤ 1), $|+⟩=1∕N∑i=0N−1|i⟩$, and f (0) = g(1) = 1 and f (1) = g(0) = 0. The eigenspectrum of this Hamiltonian can be exactly derived [see Das et al. (2003) and Orus and Latorre (2004)]. In particular, the two lowest eigenstates can be written as\n\n$|E±(s)⟩=N±(s)|m⟩+b±(s)|ϕ⟩,$\n\nwhere the normalization constant is $N±(s) = 1∕1+(N−1)b±(s)2$, $|ϕ⟩=∑i≠m|i⟩$, and\n\n$b±(s)=1−E±(s)f(s)N¯,$\n\nwith $N¯=1−1∕N$, and the corresponding energies E±(s) given by\n\n$E±(s)=f(s)+g(s)±[ f(s)+g(s)]2−4f(s)g(s)N¯2.$\n\nThe other higher-energy eigenstates form an (N − 2)-fold degenerate eigenspace, whose energy is given by\n\n$Edeg= f(s)+g(s).$\n\nIn order to explicitly provide the eigenstates $|Edegk⟩$ (k = 1, ⋯ , N − 2) associated with the eigenenergy Edeg, we write\n\n$|Edegk⟩=∑n=0N−1cnk|n⟩.$\n\nThen, from the eigenvalue equation for H0(s), it directly follows that the set ${cnk}$ is just required to satisfy the constraints $∑n=0N−1cnk=0$ and $cmk=0$. As a consequence, the states $|Edegk⟩$ can be suitably chosen as time-independent vectors.\n\nBy imposing a local adiabatic evolution (van Dam et al., 2001; Roland and Cerf, 2002), i.e., by requiring adiabaticity at each infinitesimal time interval, the runtime is minimized for the path [see also Kieferová and Wiebe (2014)]\n\n$f(s)=1−g(s),g(s)=N−1−tanarctanN−11−2s2N−1.$\n\nThis results in a quadratic speedup over the classical search, i.e., we obtain the time complexity $O(N)$ expected by the Grover quantum search (van Dam et al., 2001; Roland and Cerf, 2002).\n\nIt is possible to reduce the time complexity of the Grover quantum search by transferring the algorithmic cost to other physical resources. The second implementation of the adiabatic Grover search considered here has been introduced in Das et al. (2003) and Wen and Qiu (2008). It is also based on the Hamiltonian in equation (7) to perform the evolution, but requiring that the functions f (s) and g(s) satisfy\n\n$f(s)=1−s+N(1−s)s,$\n$g(s)=s+N(1−s)s.$\n\nThis implementation achieves the solution at constant time complexity O(1). As is apparent from equations (14) to (15), the original time resource has been transferred to the coupling strengths f (s) and g(s) and, as discussed in detail in the next Section, will be reflected in the energy scaling required by the system.\n\nThe two previous versions of the adiabatic Grover’s algorithm are based on oracular Hamiltonians, which we take here to be operators able to recognize the correct answer of a problem (Nielsen and Chuang, 2000). This is indeed the case if one chooses a Hamiltonian composed of an operator Om in the form Om = 𝟙 − |m⟩ ⟨m|. The action of Om in the computational basis {|i⟩} is\n\n$Om|i⟩=(𝟙−|m⟩⟨m|)|i⟩=0(i=m),|i⟩(i≠m),$\n\nso that this operator recognizes the marked state, providing no hint about its identity if acting upon any other state. Adiabatic versions of the quantum search have also been proposed via non-oracular Hamiltonians. Our third implementation of Grover’s algorithm is based on the non-linear non-oracular (NLNO) Hamiltonian proposed in Wen et al. (2009). In this work, the time-dependent Hamiltonian in equation (7) is replaced for\n\n$H0(s)=f(s)(𝟙−|+⟩⟨+|)+g(s)(𝟙−|m⟩⟨m|)+h(s)(|+⟩⟨m|+|m⟩⟨+|),$\n\nwhere h(0) = h(1) = 0. The Hamiltonian in equation (17) contains an operator $O¯m=|+⟩⟨m|+|m⟩⟨+|$. The action of $O¯m$ in the computational basis {|i⟩} is\n\n$O¯m|i⟩=(|+⟩⟨m|+|m⟩⟨+|)|i⟩=1N|m⟩+|+⟩(i=m),1N|m⟩(i≠m).$\n\nObserve that equation (18) implies that $O¯m$ cannot exactly recognize a marked element, even though it could effectively recover the marked state for N ≫ 1 with a single operation over the uniform superposition provided by the state |+⟩. Naturally, the non-oracular form of the Hamiltonian involves all the individual computational states, requiring, therefore, much more than the capacity of the Hamiltonian to recognize the marked element. This is an obviously artificial approach, whose discussion here is kept just for comparison with the superadiabatic scenario. Assuming a restricted feasibility of such a Hamiltonian, we proceed by looking at its eigenspectrum. The ground and first excited states have the same structure as in equation (8), with\n\n$b±(s)=N¯f(s)+2h(s)N−E±(s)N¯ f(s)−h(s)N.$\n\nThe two lowest energy levels are given by\n\n$E±(s)=12f(s)+g(s)+2h(s)N±f(s)+g(s)2−4f(s)g(s)N¯+ 4h2(s)−4h(s)N f(s)+g(s) .$\n\nAs before, the higher-energy states form an (N − 2)-fold degenerate subspace, with energy given by f(s) + g(s). As shown in Wen et al. (2009), this formulation also shows constant time complexity O(1), which can be obtained by choosing a suitable interpolation, such as\n\n$f(s)=1−s,g(s)=s,h(s)=s(1−s).$\n\nThe performance of adiabatic QC is dictated by a long total evolution time compared to the inverse of a power of the energy gap (Messiah, 1962; Teufel, 2003; Sarandy et al., 2004; Jansen et al., 2007). However, the adiabatic evolution can be sped up through shortcuts to adiabaticity via counter-diabatic Hamiltonians (Demirplak and Rice, 2003, 2005; Berry, 2009). The fundamental idea underlying these shortcuts to adiabaticity is to add a new contribution HCD(t), called counter-diabatic Hamiltonian, to the original adiabatic Hamiltonian H(t). This term is constructed such that it allows the mimicking of the adiabatic evolution, however, without any constraint on the total time of evolution. The total composite Hamiltonian is\n\n$HSA(t)=H(t)+HCD(t),$\n\nwhich is called superadiabatic Hamiltonian. In particular, it is possible to show that the counter-diabatic term reads (Berry, 2009).\n\n$HCD(t)=iℏ∑nn˙(t)n(t)+n˙(t)|n(t)n(t)n(t),$\n\nwhere |n(t)⟩ is the eigenstate of H(t) associated with the energy En(t). The goal of the counter-diabatic term HCD(t) in the Hamiltonian HSA(t) is exactly to eliminate the diabatic contributions of H(t). Thus, if the system is initially prepared in the ground state of H(0), then the system will deterministically evolve to the instantaneous ground state of the Hamiltonian H(t) with no constraints over the evolution time. Note that, in general, one would need to be able to explicitly calculate all the eigenstates of H(t) to derive a shortcut to adiabaticity using the counter-diabatic driving. However, this may not be a hard requirement in the case of superadiabatic versions of circuit implementations, where one-qubit rotations and two-qubit entangling gates are enough to achieve QC universality (Nielsen and Chuang, 2000). In particular, as we shall see for this case, HCD(t) can be realized through a simple time-independent operator.\n\n### 2.4. Energetic Cost of Quantum Evolutions\n\nTo quantify the expense of energy in a quantum evolution driven by a Hamiltonian H(t), we adopt as the cost measure the average norm of H(t) computed for a total time of evolution τ. This yields (Kieferová and Wiebe, 2014; Santos and Sarandy, 2015; Zheng et al., 2015; Santos et al., 2016)\n\n$Σ(τ)=1τ∫0τH(t)dt=∫01H(s)ds,$\n\nwhere s = t/τ is the parameterized time and the norm here is defined by the Frobenius norm (Hilbert–Schmidt norm) $A=TrA†A$. Naturally, other norms can be adopted as, for instance, the spectral norm $A2=λmaxA†A$, where λmax denotes the maximum eigenvalue of [A A]. For the Hamiltonians investigated in this work, these norms will imply into a cost simply related by a constant D1/2, with D denoting the dimension of corresponding the Hilbert space. The Frobenius norm as well as arbitrary superadiabatic evolutions with total evolution time τ, the energetic cost can be written as\n\n$ΣSA(τ)=1τ∫0τTrHSA2(t)dt=1τ∫0τTrH2(t)+HCD2(t)dt,$\n\nwhere we have used that Tr({H(t), HCD(t)}) = 0 (Santos and Sarandy, 2015). This explicitly shows that a superadiabatic evolution has an energetic cost larger than its corresponding adiabatic evolution. By evaluating the trace in equation (25), we obtain\n\n$ΣSA(τ)=∫01∑mEm2(s)+ℏ2μm(s)τ2ds,$\n\nwhere μm(s) = ⟨∂sm(s)|∂sm(s)⟩ − |⟨m(s)|∂sm(s)⟩|2 and {Em(s)} is the energy spectrum of the adiabatic Hamiltonian H(t), with {|m(s)⟩} denoting its eigenbasis. Notice that the adiabatic limit is recovered when taking τ → ∞. Thus, the speedup obtained by the superadiabatic dynamics is limited by the energetic cost of the evolution. Indeed, this energy–time complementarity can be formally discussed through the quantum speed limit (Deffner and Lutz, 2013), which suggests that the superadiabatic evolution time is compatible with arbitrarily short time intervals (implying into corresponding arbitrarily large energies) (Santos and Sarandy, 2015), while the adiabatic evolution time obeys the lower bound τAd ∝ 1/ωn, with ω associated with the energy gap and n ∈ ℕ+ (Messiah, 1962; Teufel, 2003; Sarandy et al., 2004; Jansen et al., 2007).\n\n## 3. Results\n\nWe now consider the performance of adiabatic and superadiabatic quantum computation, focusing on their time–energy complexity. This will be investigated both for the universal model of superadiabatic controlled gates and for the superadiabatic implementations of the Grover search.\n\n### 3.1. Quantum Gates by Superadiabatic Controlled Evolutions\n\nLet us begin by discussing the superadiabatic model of universal QC via CE implemented by shortcuts to adiabaticity (Santos and Sarandy, 2015). To this end, let us first write the complete set of eigenstates of H(t) as (Santos and Sarandy, 2015)\n\n$|E0mϵk(s)⟩=|m,n^ϵ⊗|E0k(s)⟩,$\n$|E0 (N−1)+k(s)⟩=|N−1,n^+⊗|E0k(s)⟩,$\n$|Eϕ (N−1)−k(s)⟩=|N−1,n^−⊗|Eϕk(s)⟩,$\n\nwhere m ∈ {0, ⋯ , N − 2}, ϵ, k ∈ { ± }, and\n\n$|Eξ+(s)⟩=−sinθ0s20+eiξcosθ0s21,$\n$|Eξ−(s)⟩=cosθ0s20+eiξsinθ0s21,$\n\nwith ξ ∈ {0, ϕ} and ${|Eξ±(s)⟩}$ denoting the set of eigenstates of each adiabatic Hamiltonian Hξ(s), as provided by equation (2). Thus, by using the equation (22), we can show that the superadiabatic Hamiltonian is given by (Santos and Sarandy, 2015)\n\n$HSA(s)=1−PN−1,n^−⊗H0SA(s)+PN−1,n^−⊗HϕSA(s),$\n\nwhere each term $HξSA(s)$ corresponds to the superadiabatic Hamiltonian associated with the adiabatic Hamiltonian Hξ(s), i.e., $HξSA(s)=Hξ(s)+HξCD$, with\n\n$HξCD=ℏθ02τσycosξ−σxsinξ$\n\nbeing the (time-independent) counter-diabatic contribution to achieve the evolution at total time τ (Santos and Sarandy, 2015).\n\n### 3.2. Energy–Time Complementarity in the CE Model of Quantum Gates\n\nLet us now consider equation (26) to investigate the time–energy complementarity relationship in both adiabatic and superadiabatic CE models of universal quantum gates. To this end, we need the set of eigenvalues and eigenstates of the adiabatic Hamiltonian in equation (1), which are given by Eqs 27–31. The spectrum of H(s) has (2N)-degenerate levels, with ${|E0mϵ+(s)⟩,|E0 (N−1)++(s)⟩,|Eϕ (N−1)−+(s)⟩}$ and ${|E0mϵ−(s)⟩,|E0 (N−1)+−(s)⟩,|Eϕ (N−1)−−(s)⟩}$ associated with the levels E+ = ℏω and E = −ℏω, respectively. So, by using Eqs 27–31, we can show that $μlm(s)=θ02∕4τ2$. In addition, the energetic cost to implement any gate controlled by n qubits is $ΣSA(τ,n)=2n∕2ΣSAsing(τ)$ (Santos and Sarandy, 2015), where $ΣSAsing$ is the energetic cost to implement any single qubit unitary transformation, with\n\n$ΣSAsingωτ,θ0=2ℏω1+θ024ωτ2.$\n\nA similar result can be obtained from the spectral norm, with energetic cost given by $ΣSAsingωτ,θ0|2=(1∕2)ΣSAsingωτ,θ0$, since the Hilbert space has dimension D = 4 in this case. Note that the energetic cost is independent of the parameter θ0 in the adiabatic limit ωτ → ∞. Therefore, the best computational adiabatic strategy is to set θ = π, which deterministically ensures the implementation of the gate with probability one. On the other hand, probabilistic quantum computation can be energetically favored in the superadiabatic regime. Indeed, from equation (5), we can see that, by setting 0 < θ0 < π, the implementation of the quantum gate is achieved with a non-vanishing probability. Thus, we can investigate whether or not it is possible to find out a specific value of θ0 such that the energetic cost is better in average than the deterministic choice θ0 = π. To address this point, let us define the quantity\n\n$⟨N⟩=1sin2θ0∕2,$\n\nwhich is the average number of evolutions for a successful computation. So, the average energetic cost to implement a probabilistic evolution is\n\n$Σ¯=⟨N⟩Σ,$\n\nwhere Σ is the cost of a single evolution. Without loss of generality, we will consider the cost of single gates, since similar arguments apply for the cost of n-qubit controlled gates. So, by performing superadiabatic probabilistic quantum computing, the average energetic cost is given by\n\n$Σ¯SAsingωτ,θ0=NΣSAsingωτ,θ0=2ℏωcsc2θ021+θ024ωτ2.$\n\nThe function $Σ¯SAsingωτ,θ0 → ∞$ as θ0 → 0 and exhibits a minimum in the interval 0 < θ0 < π as a function of ωτ. Indeed, the angle $θ0min$ that minimizes $Σ¯SAsingωτ,θ0$ grows monotonically with ωτ, with $θ0min→π$ as ωτ → ∞ (adiabatic limit). Then, optimizing $Σ¯SAsingωτ,θ0$ for θ0, we obtain\n\n$∂∂θ0Σ¯SAsingωτ,θ0=ηθ0,ωτθ0−4ωτ2+θ02cotanθ02=0,$\n\nwhere we have defined the function\n\n$ηθ0,ωτ=csc2θ0∕22ωτ21+θ02∕4ωτ2.$\n\nNote that η(θ0, ωτ) is non-vanishing in the whole interval $Iθ0 ∈ 0,π$. Thus, to obtain the critical angle $θ0min$ in $Σ¯SAsingωτ,θ0$, we use equation (38) to note that ωτ satisfies\n\n$ωτ=θ0min2tanθ0min2−θ0min,$\n\nwhere we can see a dependence of $θ0min$ on the choice of ωτ. In addition, note that $θ0min$ is such that $tanθ0min2 ≥ θ0min$, since the quantity ωτ is required to be real and positive. The probabilistic advantage is plotted in Figure 1, where it is shown that the optimal value for θ0 is a continuous function of ωτ, being distinct of the deterministic implementation θ0 = π. In the inset, we show the global minimum of the average energy for ωτ = 0.01, which occurs for θ0 < π. In particular, $θ0min$ moves away from π as ωτ is lowered, i.e., in the strong superadiabatic regime. As ωτ shifts toward the adiabatic limit, we find that $θ0min→π$. The optimization of the energy cost is shown in the lower inset, where we define the fraction of energy required by the optimized probabilistic model as a function of ωτ as\n\n$Σrelωτ=Σ¯SAsing(ωτ,θ0min)ΣSAsingωτ,π.$\nFIGURE 1",
null,
"Figure 1. Optimal value $θ0min$ for the angle parameter θ0 as a function of ωτ, with ωτ in logarithmic scale. The points are obtained from equation (40), with the curve denoting the numerical fit. Upper inset: average energy in units of ℏω as a function of θ0 for ωτ = 0.01. The results are obtained from equation (37). Lower inset: fraction Σrel(ωτ) of energy required by the optimized probabilistic model as a function of ωτ, with data in logarithmic scale. The points are obtained from equation (41), with the curve denoting the numerical fit.\n\nNotice that Σrel(ωτ) decreases in the superadiabatic regime, implying into a large reduction of the energetic cost for small values of ωτ. On the other hand, Σrel(ωτ) →1 in the adiabatic limit, since $θ0min→π$.\n\nHere, we derive a superadiabatic Hamiltonian HSA(s) for the oracular quantum search governed by the adiabatic Hamiltonian H0(s) in equation (7). We will adopt linear interpolation, with f (s) = 1 − s and g(s) = s, as in Farhi et al. (2000) and write HSA(s) = H0(s) + HCD(s). In order to determine the counter-diabatic Hamiltonian HCD(s), we observe that, since H0(s) has real eigenstates, we use that $⟨n˙(s)|n(s)⟩=0$ in equation (23), which implies that\n\n$HCD(s)=iℏτ∑ξ=±|E˙ξ(s)⟩⟨Eξ(s)|,$\n\nwhere the energies |E±(s)⟩ are given by equation (8) and\n\n$|E˙±(s)⟩=−(N−1)b±b˙±(1+(N−1)b±2)3∕2|m⟩+b˙±(1+(N−1)b±2)3∕2|ϕ⟩.$\n\nNote that only the ground and first excited states contribute to HCD(s), since the higher-energy degenerate sector ${|Edegk⟩}$ is composed by time-independent eigenvectors [see equation (12)]. Note also that the counter-diabatic Hamiltonian will naturally be non-oracular [see equation (18)], with contributions from operators, such as |ϕ⟩ ⟨m| and |m⟩ ⟨ϕ|. This is the reason behind the time complexity O(1) for the superadiabatic Hamiltonian. Naturally, such a result leads to an artificial approach. In a more physical scenario, superadiabaticity could be applied to the quantum search via the direct implementation of the Grover quantum circuit, through the controlled evolution approach discussed in Section 3.1.\n\n### 3.4. Energy–Time Complementarity in the Quantum Search\n\nLet us now analyze the time–energy complementarity relationship in the adiabatic and superadiabatic versions of the Grover search. In the adiabatic regime, the energetic cost can be computed from equation (26) and using τ → ∞. Therefore, the adiabatic cost can be written as\n\n$Σad=∫01ds∑mEm2(s)=∫01dsE+(s)2+E−(s)2+(N−2)Edeg(s)2.$\n\nLet us initially consider the oracular Hamiltonian H0(s) in equation (7), whose eigenvalues are given by equations (10) and (11). By considering the case of local adiabatic evolution provided by the interpolation in equation (13) and by taking N ≫ 1, we obtain E±(s) ∼ Edeg(s) ∼ O(1), which implies from equation (44) into an energetic cost $ΣadLA$ that scales as $O(N)$. On the other hand, in the superenergetic version of the quantum search, we adopt the interpolation in Eqs 14 and 15. Then, by taking N ≫ 1, we obtain now $E±(s)∼Edeg(s)∼O(N)$, which implies into an energetic cost $ΣadSE$ that scales as O(N). This higher energetic cost is a consequence of the complementarity between energy and time, which arises to compensate the constant time complexity O(1) of the superenergetic version. Naturally, the composite energy–time complexity is kept constant for both cases. This overall complexity is reduced by taking non-oracular artificial Hamiltonians. In the case of the adiabatic NLNO model, we use the Hamiltonian in equation (17), whose ground state and first excited state energies are given now by equation (20), with the higher energies kept as in equation (11). Its energetic cost $ΣadNO$ can also be computed from equation (44) by considering the interpolation in equation (21) and by taking N ≫ 1. Then, we obtain E±(s) ∼ Edeg(s) ∼ O(1), which yields $ΣadNO$ scaling as $O(N)$.\n\nFor the superadiabatic algorithm, equation (26) must be used. Without loss of generality, we set energy units such that /τ = 1. We find that for N ≫ 1, the value of μ±(s) in equation (26) evaluate to\n\n$μ±(s)=⟨E˙±(s)|E˙±(s)⟩=(N−1)b˙±(s)2(1+(N−1)b±(s)2)2,$\n\nwhich in turn gives the superadiabatic search energetic cost ΣSA of order $O(N)$, just reproducing the scaling of the NLNO adiabatic search. Similar results can be obtained if one chooses the spectral norm in the energetic cost, up to a common scaling factor $D1∕2=N$ related to the dimension of the Hilbert space. These results are summarized in Table 1.\n\nTABLE 1",
null,
"Table 1. Energy–time complexity for several versions of oracular and non-oracular Hamiltonians for the Grover quantum search.\n\n## 4. Discussion\n\nImplications of probabilistic superadiabatic QC under decoherence is a further challenge of immediate interest. In a quantum open-systems scenario, there is a compromise between the time required by adiabaticity and the decoherence time of the quantum device. Therefore, a superadiabatic implementation may provide a direction to obtain an optimal running time for the quantum algorithm while keeping an inherent protection against decoherence. In this context, it is our interest to understand to what extent decoherence can affect the optimal angle $θ0min$, investigating in particular if it can be robust against classes of decohering processes. Concerning specifically the Grover search, it would be interesting to understand whether superadiabatic implementations are equivalent to arbitrary non-oracular adiabatic Hamiltonians, as suggested in our present discussion. Moreover, the behavior of correlations, such as entanglement and the investigation of experimental proposals in the superadiabatic scenario are also topics under investigation.\n\n## Author Contributions\n\nAll the authors equally contributed to the conception of the work, development of the main results, and writing of the manuscript.\n\n## Conflict of Interest Statement\n\nThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.\n\n## Funding\n\nMS thanks Daniel Lidar for his hospitality at the University of Southern California. IC, AS, and MS acknowledge support from CNPq/Brazil and the Brazilian National Institute for Science and Technology of Quantum Information (INCT-IQ).\n\n## References\n\nBarends, R., Shabani, A., Lamata, L., Kelly, J., Mezzacapo, A., Las Heras, U., et al. (2016). Digitized adiabatic quantum computing with a superconducting circuit. Nature 534, 222–226. doi: 10.1038/nature17658\n\nBerry, M. V. (2009). Transitionless quantum driving. J. Phys. A: Math. Theor. 42, 365303. doi:10.1088/1751-8113/42/36/365303\n\nBocharov, A., Roetteler, M., and Svore, K. M. (2015). Efficient synthesis of universal repeat-until-success quantum circuits. Phys. Rev. Lett. 114, 080502. doi:10.1103/PhysRevLett.114.080502\n\nChen, Y. H., Xia, Y., Chen, Q. Q., and Song, J. (2014a). Efficient shortcuts to adiabatic passage for fast population transfer in multiparticle systems. Phys. Rev. A 89, 033856. doi:10.1103/PhysRevA.89.033856\n\nChen, Y.-H., Xia, Y., Chen, Q. Q., and Song, J. (2014b). Shortcuts to adiabatic passage for multiparticles in distant cavities: applications to fast and noise-resistant quantum population transfer, entangled states preparation and transition. Laser Phys. Lett. 11, 115201. doi:10.1088/1612-2011/11/11/115201\n\nChen, Y.-H., Xia, Y., Chen, Q. Q., and Song, J. (2015a). Fast and noise-resistant implementation of quantum phase gates and creation of quantum entangled states. Phys. Rev. A 91, 012325. doi:10.1103/PhysRevA.91.012325\n\nChen, Y.-H., Xia, Y., Song, J., and Chen, Q.-Q. (2015b). Shortcuts to adiabatic passage for fast generation of Greenberger-Horne-Zeilinger states by transitionless quantum driving. Sci. Rep. 5, 15616. doi:10.1038/srep15616\n\nDas, S., Kobes, R., and Kunstatter, G. (2003). Energy and efficiency of adiabatic quantum search algorithms. J. Phys. A: Math. Gen. 36, 2839. doi:10.1088/0305-4470/36/11/313\n\nDeffner, S., and Lutz, E. (2013). Energy time uncertainty relation for driven quantum systems. J. Phys. A: Math. Theor. 46, 335302. doi:10.1088/1751-8113/46/33/335302\n\ndel Campo, A. (2013). Shortcuts to adiabaticity by counter-diabatic driving. Phys. Rev. Lett. 111, 100502. doi:10.1103/PhysRevLett.111.100502\n\ndel Campo, A., Rams, M. M., and Zurek, W. H. (2012). Assisted finite-rate adiabatic passage across a quantum critical point: exact solution for the quantum Ising model. Phys. Rev. Lett. 109, 115703. doi:10.1103/PhysRevLett.109.115703\n\nDemirplak, M., and Rice, S. A. (2003). Adiabatic population transfer with control fields. J. Phys. Chem. A 107, 9937. doi:10.1021/jp030708a\n\nDemirplak, M., and Rice, S. A. (2005). Assisted adiabatic passage revisited. J. Phys. Chem. B 109, 6838. doi:10.1021/jp040647w\n\nFarhi, E., Goldstone, J., Gutmann, S., Lapan, J., Lundgren, A., and Preda, D. (2001). A quantum adiabatic evolution algorithm applied to random instances of an NP-complete problem. Science 292, 472. doi:10.1126/science.1057726\n\nFarhi, E., Goldstone, J., Gutmann, S., and Sipser, M. (2000). Quantum computation by adiabatic evolution. MIT-CTP-2936 (arXiv:quant-ph/0001106).\n\nGrover, L. K. (1997). Quantum mechanics helps in searching for a needle in a haystack. Phys. Rev. Lett. 79, 325. doi:10.1103/PhysRevLett.79.325\n\nHen, I. (2015). Quantum gates with controlled adiabatic evolutions. Phys. Rev. A 91, 022309. doi:10.1103/PhysRevA.91.022309\n\nJansen, S., Ruskai, M.-B., and Seiler, R. (2007). Bounds for the adiabatic approximation with applications to quantum computation. J. Math. Phys. 48, 102111. doi:10.1063/1.2798382\n\nKieferová, M., and Wiebe, N. (2014). On the power of coherently controlled quantum adiabatic evolutions. New J. Phys. 16, 123034. doi:10.1088/1367-2630/16/12/123034\n\nLu, M., Xia, Y., Shen, L. T., and Song, J. (2014a). An effective shortcut to adiabatic passage for fast quantum state transfer in a cavity quantum electronic dynamics system. Laser Phys. 24, 105201. doi:10.1088/1054-660X/24/10/105201\n\nLu, M., Xia, Y., Shen, L. T., Song, J., and An, N. B. (2014b). Shortcuts to adiabatic passage for population transfer and maximum entanglement creation between two atoms in a cavity. Phys. Rev. A 89, 012326. doi:10.1103/PhysRevA.89.012326\n\nMartinis, J. M., and Geller, M. R. (2014). Fast adiabatic qubit gates using only σz control. Phys. Rev. A 90, 022307. doi:10.1103/PhysRevA.90.022307\n\nMessiah, A. (1962). Quantum Mechanics. North-Holland, Amsterdam: North-Holland Pub. Co.\n\nNielsen, M. A., and Chuang, I. L. (2000). Quantum Computation and Quantum Information. Cambridge: Cambridge University Press.\n\nOrus, R., and Latorre, J. I. (2004). Universality of entanglement and quantum computation complexity. Phys. Rev. A 69, 052308. doi:10.1103/PhysRevA.69.052308\n\nPaetznick, A., and Svore, K. M. (2014). Repeat-until-success: non-deterministic decomposition of single-qubit unitaries. Quantum Inf. Comput. 14, 1277.\n\nRoland, J., and Cerf, N. J. (2002). Quantum search by local adiabatic evolution. Phys. Rev. A 65, 042308. doi:10.1103/PhysRevA.65.042308\n\nSaberi, H., Opatrny, T., Molmer, K., and del Campo, A. (2014). Adiabatic tracking of quantum many-body dynamics. Phys. Rev. A 90, 060301(R). doi:10.1103/PhysRevA.90.060301\n\nSantos, A. C., and Sarandy, M. S. (2015). Superadiabatic controlled evolutions and universal quantum computation. Sci. Rep. 5, 15775. doi:10.1038/srep15775\n\nSantos, A. C., Silva, R. D., and Sarandy, M. S. (2016). Shortcut to adiabatic gate teleportation. Phys. Rev. A 93, 012311. doi:10.1103/PhysRevA.93.012311\n\nSarandy, M. S., Wu, L.-A., and Lidar, D. (2004). Consistency of the adiabatic theorem. Quantum Inf. Process. 3, 331. doi:10.1007/s11128-004-7712-7\n\nTeufel, S. (2003). “Adiabatic perturbation theory in quantum dynamics,” in Lecture Notes in Mathematics, Vol. 1821 (Berlin Heidelberg: Springer-Verlag).\n\nTorrontegui, E., Ibáñez, S., Martínez-Garaot, S., Modugno, M., del Campo, A., Guéry-Odelin, D., et al. (2013). Shortcuts to adiabaticity. Adv. Atom. Mol. Opt. Phys. 62, 117. doi:10.1016/B978-0-12-408090-4.00002-5\n\nvan Dam, W., Mosca, M., and Vazirani, U. (2001). “How powerful is adiabatic quantum computation?,” in Proceedings of the 42nd Annual Symposium on Foundations of Computer Science, Las Vegas, 279.\n\nWen, J., Huang, Y., and Qiu, D. (2009). Entanglement proprieties of adiabatic quantum algorithms. Int. J. Quantum Inform. 7, 1531. doi:10.1142/S0219749909006000\n\nWen, J., and Qiu, D. (2008). Entanglement in adiabatic quantum searching algorithms. Int. J. Quantum Inform. 6, 997. doi:10.1142/S0219749908004249\n\nZheng, Y., Campbell, S., Chiara, G., and Poletti, D. (2015). Cost of transitionless driving and work output. e-print arXiv:1509.01882\n\nKeywords: quantum computing, quantum information, shortcuts to adiabaticity, superadiabaticity, quantum gates, quantum search\n\nCitation: Coulamy IB, Santos AC, Hen I and Sarandy MS (2016) Energetic Cost of Superadiabatic Quantum Computation. Front. ICT 3:19. doi: 10.3389/fict.2016.00019\n\nReceived: 29 March 2016; Accepted: 23 August 2016;\nPublished: 15 September 2016\n\nEdited by:"
] | [
null,
"https://crossmark-cdn.crossref.org/widget/v2.0/logos/CROSSMARK_Color_square.svg",
null,
"https://www.frontiersin.org/files/Articles/202223/fict-03-00019-HTML/image_t/fict-03-00019-g001.gif",
null,
"https://www.frontiersin.org/files/Articles/202223/fict-03-00019-HTML/image_t/fict-03-00019-t001.gif",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8398711,"math_prob":0.9868201,"size":35434,"snap":"2019-26-2019-30","text_gpt3_token_len":9244,"char_repetition_ratio":0.1732148,"word_repetition_ratio":0.044207036,"special_character_ratio":0.25193316,"punctuation_ratio":0.18330465,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9949713,"pos_list":[0,1,2,3,4,5,6],"im_url_duplicate_count":[null,null,null,1,null,1,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-07-19T14:25:29Z\",\"WARC-Record-ID\":\"<urn:uuid:920a7f45-1837-4578-a822-c6ec617912f6>\",\"Content-Length\":\"258532\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:f5473216-9ebe-429d-9fa2-c7e108b2dca1>\",\"WARC-Concurrent-To\":\"<urn:uuid:1d0b7e4c-3af7-4d66-979d-8086254ea8fc>\",\"WARC-IP-Address\":\"134.213.70.247\",\"WARC-Target-URI\":\"https://www.frontiersin.org/articles/10.3389/fict.2016.00019/full\",\"WARC-Payload-Digest\":\"sha1:JIWLQU4LTDK74HWSPIHWNVVB6XUV47DF\",\"WARC-Block-Digest\":\"sha1:IFJFJX5JMNOGS5C65HB6WX2RT7XCOABC\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-30/CC-MAIN-2019-30_segments_1563195526254.26_warc_CC-MAIN-20190719140355-20190719162355-00547.warc.gz\"}"} |
https://stablemarkets.wordpress.com/2019/03/ | [
"# Efficient MCMC with Caching\n\nThis post is part of a running series on Bayesian MCMC tutorials. For updates, follow @StableMarkets. Metropolis Review Metropolis-Hastings is an MCMC algorithm for drawing samples from a distribution known up to a constant of proportionality, $latex p(\\theta | y) \\propto p(y|\\theta)p(\\theta)$. Very briefly, the algorithm works by starting with some initial draw $latex \\theta^{(0)}$ then running … Continue reading Efficient MCMC with Caching"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.86679035,"math_prob":0.83698344,"size":445,"snap":"2019-43-2019-47","text_gpt3_token_len":107,"char_repetition_ratio":0.09977324,"word_repetition_ratio":0.0,"special_character_ratio":0.21348314,"punctuation_ratio":0.08,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9811637,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-11-15T00:06:14Z\",\"WARC-Record-ID\":\"<urn:uuid:619e0aa9-11f1-49f4-a319-ab1612673d14>\",\"Content-Length\":\"78093\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:2ddb1b20-4000-47be-a957-eaa9560ee549>\",\"WARC-Concurrent-To\":\"<urn:uuid:4d2d211e-34ad-45fa-ad59-eaf01fcedf6a>\",\"WARC-IP-Address\":\"192.0.78.13\",\"WARC-Target-URI\":\"https://stablemarkets.wordpress.com/2019/03/\",\"WARC-Payload-Digest\":\"sha1:DKKC6755X3XJTT6CDA5CTWZS4KUUEAWV\",\"WARC-Block-Digest\":\"sha1:W5STQMIUOQNJQTJX2HLREAJLEEDCEEKI\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-47/CC-MAIN-2019-47_segments_1573496668544.32_warc_CC-MAIN-20191114232502-20191115020502-00184.warc.gz\"}"} |
https://timsong-cpp.github.io/cppwp/n4659/valarray.cons | [
"# 29 Numerics library [numerics]\n\n## 29.7 Numeric arrays [numarray]\n\n### 29.7.2 Class template valarray[template.valarray]\n\n#### 29.7.2.2valarray constructors [valarray.cons]\n\n```valarray(); ```\n\nEffects: Constructs a valarray that has zero length.277\n\n```explicit valarray(size_t n); ```\n\nEffects: Constructs a valarray that has length n. Each element of the array is value-initialized.\n\n```valarray(const T& v, size_t n); ```\n\nEffects: Constructs a valarray that has length n. Each element of the array is initialized with v.\n\n```valarray(const T* p, size_t n); ```\n\nRequires: p points to an array ([dcl.array]) of at least n elements.\n\nEffects: Constructs a valarray that has length n. The values of the elements of the array are initialized with the first n values pointed to by the first argument.278\n\n```valarray(const valarray& v); ```\n\nEffects: Constructs a valarray that has the same length as v. The elements are initialized with the values of the corresponding elements of v.279\n\n```valarray(valarray&& v) noexcept; ```\n\nEffects: Constructs a valarray that has the same length as v. The elements are initialized with the values of the corresponding elements of v.\n\nComplexity: Constant.\n\n```valarray(initializer_list<T> il); ```\n\nEffects: Equivalent to valarray(il.begin(), il.size()).\n\n```valarray(const slice_array<T>&); valarray(const gslice_array<T>&); valarray(const mask_array<T>&); valarray(const indirect_array<T>&); ```\n\nThese conversion constructors convert one of the four reference templates to a valarray.\n\n```~valarray(); ```\n\nEffects: The destructor is applied to every element of *this; an implementation may return all allocated memory.\n\nThis default constructor is essential, since arrays of valarray may be useful. After initialization, the length of an empty array can be increased with the resize member function.\n\nThis constructor is the preferred method for converting a C array to a valarray object.\n\nThis copy constructor creates a distinct array rather than an alias. Implementations in which arrays share storage are permitted, but they shall implement a copy-on-reference mechanism to ensure that arrays are conceptually distinct."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6846369,"math_prob":0.95534515,"size":1539,"snap":"2019-13-2019-22","text_gpt3_token_len":328,"char_repetition_ratio":0.19413681,"word_repetition_ratio":0.12903225,"special_character_ratio":0.20987654,"punctuation_ratio":0.14234875,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9907688,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-03-23T00:26:25Z\",\"WARC-Record-ID\":\"<urn:uuid:86bc15a6-cc70-4714-99ea-2dc45c1183e6>\",\"Content-Length\":\"9784\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:494ad421-a400-44ff-839d-11d68816fcfa>\",\"WARC-Concurrent-To\":\"<urn:uuid:5776ab81-b948-4a64-9e81-651449db63b2>\",\"WARC-IP-Address\":\"185.199.110.153\",\"WARC-Target-URI\":\"https://timsong-cpp.github.io/cppwp/n4659/valarray.cons\",\"WARC-Payload-Digest\":\"sha1:IVE3GJUEH7IY5K6VXJOCS4RLC6E65X5J\",\"WARC-Block-Digest\":\"sha1:3KGQT4KO6JONCSTYNMQ6WGPQGCCJ66BM\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-13/CC-MAIN-2019-13_segments_1552912202704.58_warc_CC-MAIN-20190323000443-20190323022443-00480.warc.gz\"}"} |
https://artofproblemsolving.com/wiki/index.php?title=1994_AIME_Problems/Problem_13&diff=30348&oldid=28428 | [
"# Difference between revisions of \"1994 AIME Problems/Problem 13\"\n\n## Problem\n\nThe equation",
null,
"$x^{10}+(13x-1)^{10}=0\\,$\n\nhas 10 complex roots",
null,
"$r_1, \\overline{r_1}, r_2, \\overline{r_2}, r_3, \\overline{r_3}, r_4, \\overline{r_4}, r_5, \\overline{r_5},\\,$ where the bar denotes complex conjugation. Find the value of",
null,
"$\\frac 1{r_1\\overline{r_1}}+\\frac 1{r_2\\overline{r_2}}+\\frac 1{r_3\\overline{r_3}}+\\frac 1{r_4\\overline{r_4}}+\\frac 1{r_5\\overline{r_5}}.$\n\n## Solution\n\nLet",
null,
"$t = 1/x$. After multiplying the equation by",
null,
"$t^{10}$,",
null,
"$1 + (13 - t)^{10} = 0\\Rightarrow (13 - t)^{10} = - 1$.\n\nUsing DeMoivre,",
null,
"$13 - t = \\text{cis}\\left(\\frac {(2k + 1)\\pi}{10}\\right)$ where",
null,
"$k$ is an integer between",
null,
"$0$ and",
null,
"$9$.",
null,
"$t = 13 - \\text{cis}\\left(\\frac {(2k + 1)\\pi}{10}\\right) \\Rightarrow \\bar{t} = 13 - \\text{cis}\\left(-\\frac {(2k + 1)\\pi}{10}\\right)$.\n\nSince",
null,
"$\\text{cis}(\\theta) + \\text{cis}(-\\theta) = 2\\cos(\\theta)$,",
null,
"$t\\bar{t} = 170 - 26\\cos \\left(\\frac {(2k + 1)\\pi}{10}\\right)$ after expanding. Here",
null,
"$k$ ranges from 0 to 4 because two angles which sum to",
null,
"$2\\pi$ are involved in the product.\n\nThe expression to find is",
null,
"$\\sum t\\bar{t} = 850 - 26\\sum_{k = 0}^4 \\cos \\frac {(2k + 1)\\pi}{10}$.\n\nBut",
null,
"$\\cos \\frac {\\pi}{10} + \\cos \\frac {9\\pi}{10} = \\cos \\frac {3\\pi}{10} + \\cos \\frac {7\\pi}{10} = \\cos \\frac {\\pi}{2} = 0$ so the sum is",
null,
"$\\boxed{850}$."
] | [
null,
"https://latex.artofproblemsolving.com/7/3/e/73ef5b72d76840f828b8eded9fe5a63bba1d2958.png ",
null,
"https://latex.artofproblemsolving.com/9/6/0/96085a8136e254533acb15da0fa3a66dd66f6675.png ",
null,
"https://latex.artofproblemsolving.com/3/d/f/3df94cc625c07e4055d82e8eef058b98b14fde99.png ",
null,
"https://latex.artofproblemsolving.com/6/3/9/6394005e2cce77fd6160d821d368074decc504dc.png ",
null,
"https://latex.artofproblemsolving.com/9/0/8/908eb84285dc4794d5bf9cd93bfd22cadcf9e0d8.png ",
null,
"https://latex.artofproblemsolving.com/1/2/2/122d20f8fafc6474f3f3d3c7317e812e83610418.png ",
null,
"https://latex.artofproblemsolving.com/4/e/b/4ebe7135919c2ec9a555dc3d5346061cdaa953f6.png ",
null,
"https://latex.artofproblemsolving.com/8/c/3/8c325612684d41304b9751c175df7bcc0f61f64f.png ",
null,
"https://latex.artofproblemsolving.com/b/c/1/bc1f9d9bf8a1b606a4188b5ce9a2af1809e27a89.png ",
null,
"https://latex.artofproblemsolving.com/b/f/2/bf2c9074b396e3af0dea52d792660eea1c77f10f.png ",
null,
"https://latex.artofproblemsolving.com/9/d/b/9db63ea6ee7ed40f3da11331fefc4c5f3820363c.png ",
null,
"https://latex.artofproblemsolving.com/4/c/5/4c5cc1e448556a53bc38c7963c8700d30b026dd5.png ",
null,
"https://latex.artofproblemsolving.com/9/6/2/96252c856625cb6370a1022de069b478ce1edf61.png ",
null,
"https://latex.artofproblemsolving.com/8/c/3/8c325612684d41304b9751c175df7bcc0f61f64f.png ",
null,
"https://latex.artofproblemsolving.com/7/0/9/709acef3551b886e6754de72d59a88f00660f0d3.png ",
null,
"https://latex.artofproblemsolving.com/2/2/f/22f53ad4b1e4cfe03be2ce6eff08e645d24f1dae.png ",
null,
"https://latex.artofproblemsolving.com/4/1/f/41f599490089a11f562b33f0eabe91120e03029d.png ",
null,
"https://latex.artofproblemsolving.com/9/3/1/93171c7d4fcdd25e8c3690afeb801531b871947a.png ",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6129785,"math_prob":1.0000085,"size":2246,"snap":"2021-31-2021-39","text_gpt3_token_len":833,"char_repetition_ratio":0.18108831,"word_repetition_ratio":0.32152587,"special_character_ratio":0.44033837,"punctuation_ratio":0.073903,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":1.0000072,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-09-24T01:14:54Z\",\"WARC-Record-ID\":\"<urn:uuid:59c2a334-46ea-4343-b649-76128fa5212f>\",\"Content-Length\":\"48161\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:9bf5e59f-0aa1-4aa7-933f-15437d1b3fba>\",\"WARC-Concurrent-To\":\"<urn:uuid:f25ea4ee-0198-4c16-9010-8135628be829>\",\"WARC-IP-Address\":\"104.26.11.229\",\"WARC-Target-URI\":\"https://artofproblemsolving.com/wiki/index.php?title=1994_AIME_Problems/Problem_13&diff=30348&oldid=28428\",\"WARC-Payload-Digest\":\"sha1:47ZNIF46NQ6SPG4DFAL3CKEMFCMLOHI5\",\"WARC-Block-Digest\":\"sha1:H4QVY6H25NI54EPKDFU4CPCWWV5UNUKT\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-39/CC-MAIN-2021-39_segments_1631780057479.26_warc_CC-MAIN-20210923225758-20210924015758-00243.warc.gz\"}"} |
https://runestone.academy/ns/books/published//TeacherCSP/CSPNameNumbers/expressionTable.html | [
"Summary of Expression Types¶\n\n Expression Arithmetic meaning 1 + 2 Addition, the result is 3 3 * 4 Multiplication, the result is 12 1 / 3 Integer division, the result is 0 in older Python environments, but 0.333333333333 in Python 3 2.0 / 4.0 Division, the result is 0.5, since you are using decimal numbers in the calculation 2 % 3 Modulo (remainder), the result is 2 -1 Negation, the result is -1"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.82041097,"math_prob":0.9975239,"size":470,"snap":"2022-05-2022-21","text_gpt3_token_len":150,"char_repetition_ratio":0.22103004,"word_repetition_ratio":0.0,"special_character_ratio":0.34893617,"punctuation_ratio":0.13043478,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9927589,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-01-20T10:13:33Z\",\"WARC-Record-ID\":\"<urn:uuid:df8a49c2-31aa-408d-9990-f0adeeded3d8>\",\"Content-Length\":\"26285\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:b58c2655-b54f-4e76-9732-b7dd539488b1>\",\"WARC-Concurrent-To\":\"<urn:uuid:c5f5fb6e-d875-4105-838d-45f24797aefd>\",\"WARC-IP-Address\":\"134.122.31.165\",\"WARC-Target-URI\":\"https://runestone.academy/ns/books/published//TeacherCSP/CSPNameNumbers/expressionTable.html\",\"WARC-Payload-Digest\":\"sha1:XK3UFHHCARCUQHE7QUFHUEVMDQ62VGWX\",\"WARC-Block-Digest\":\"sha1:U7HZWHQV3ARQPUR2Z6VBTEXNXLKC4A6I\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-05/CC-MAIN-2022-05_segments_1642320301737.47_warc_CC-MAIN-20220120100127-20220120130127-00679.warc.gz\"}"} |
https://www.coursehero.com/file/p5kgta7/pts-Consider-the-linear-transformation-T-R-3-P-3-R-given-byT-a-b-c-a-bx-a-b-x-3/ | [
"# Pts consider the linear transformation t r 3 p 3 r\n\n• Test Prep\n• 8\n• 100% (2) 2 out of 2 people found this document helpful\n\nThis preview shows page 3 - 8 out of 8 pages.\n\nProblem 1 (20 pts).Consider the linear transformationT:R3P3(R) given byTabc=a+bx+ (a+b)x3.(a) Find the matrix [T]γβofTrelative to the standard basesβandγofR3andP3(R).(b) Explain whyTis neither 1-1 nor onto.3\nProblem 2 (30 pts).LetVbe the set of matrices defined as follows:V=a-bbaa, bR.(a) Show thatVis a vector space overR.(b) Give a basis forVand find dimV.4\n(c) ConsiderC, the set of complex numbers, as a vector space overR.Give a basis forCand find its dimension.(d) Letf:VCbe a function defined byfa-bba=a+ibfor alla, bR.Prove thatfis an isomorphism of vectors spaces overR.5\nProblem 3 (20 pts).LetVbe a vector space and letL(V, V) be the vector space of all lineartransformations fromVtoV.(a) State what it means for several linear transformationsT1, T2, . . . , TkfromVtoVto belinearly independent inL(V, V).(b) LetV=P5(R). LetTandUbe linear transformations fromVtoVdefined byT(f(x)) =f(2) +f0(x) andU(f(x)) =f00(x) for all polynomialsf(x)V.Prove thatTandUare linearly independent inL(V, V).6\nProblem 4 (10 pts).LetVbe a vector space of dimension 2017. LetT:VVbe a lineartransformation and let~vbe some vector inV. Prove that for a large enough positive integermthevectors~v, T(~v), T2(~v), T3(~v), . . . , Tm(~v)will be linearlydependentinV.7\n•",
null,
"•",
null,
"•",
null,
""
] | [
null,
"https://www.coursehero.com/assets/img/doc-landing/start-quote.svg",
null,
"https://www.coursehero.com/assets/img/doc-landing/start-quote.svg",
null,
"https://www.coursehero.com/assets/img/doc-landing/start-quote.svg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6594304,"math_prob":0.99656105,"size":1257,"snap":"2021-43-2021-49","text_gpt3_token_len":434,"char_repetition_ratio":0.12769353,"word_repetition_ratio":0.0,"special_character_ratio":0.2728719,"punctuation_ratio":0.17343174,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.996373,"pos_list":[0,1,2,3,4,5,6],"im_url_duplicate_count":[null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-10-21T05:37:55Z\",\"WARC-Record-ID\":\"<urn:uuid:295e7259-dd49-4d9e-ae0a-54397c103310>\",\"Content-Length\":\"278626\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:c77ffdd0-6550-487e-a717-4d562ea42f40>\",\"WARC-Concurrent-To\":\"<urn:uuid:05d68b14-8800-49b9-87a2-235967ebe7be>\",\"WARC-IP-Address\":\"104.17.93.47\",\"WARC-Target-URI\":\"https://www.coursehero.com/file/p5kgta7/pts-Consider-the-linear-transformation-T-R-3-P-3-R-given-byT-a-b-c-a-bx-a-b-x-3/\",\"WARC-Payload-Digest\":\"sha1:OKTZVZ3CIRGQJ5G47AGVNHAN7T4FRJFF\",\"WARC-Block-Digest\":\"sha1:FCSZDFF7HOGQZCBLQQ3J674HZCRSDVIJ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-43/CC-MAIN-2021-43_segments_1634323585381.88_warc_CC-MAIN-20211021040342-20211021070342-00157.warc.gz\"}"} |
https://everything.explained.today/Closure_(topology)/ | [
"Closure (topology) explained\n\nIn mathematics, the closure of a subset S of points in a topological space consists of all points in S together with all limit points of S. The closure of S may equivalently be defined as the union of S and its boundary, and also as the intersection of all closed sets containing S. Intuitively, the closure can be thought of as all the points that are either in S or \"near\" S. A point which is in the closure of S is a point of closure of S. The notion of closure is in many ways dual to the notion of interior.\n\nDefinitions\n\nPoint of closure\n\nFor\n\nS\n\na subset of a Euclidean space,\n\nx\n\nis a point of closure of\n\nS\n\nif every open ball centered at\n\nx\n\ncontains a point of\n\nS\n\n(this point may be\n\nx\n\nitself).\n\nThis definition generalizes to any subset\n\nS\n\nof a metric space\n\nX.\n\nFully expressed, for\n\nX\n\na metric space with metric\n\nd,\n\nx\n\nis a point of closure of\n\nS\n\nif for every\n\nr>0\n\nthere exists some\n\ns\\inS\n\nsuch that the distance\n\nd(x,s)<r\n\n(again,\n\nx=s\n\nis allowed). Another way to express this is to say that\n\nx\n\nis a point of closure of\n\nS\n\nif the distance\n\nd(x,S):=infsd(x,s)=0.\n\nThis definition generalizes to topological spaces by replacing \"open ball\" or \"ball\" with \"neighbourhood\". Let\n\nS\n\nbe a subset of a topological space\n\nX.\n\nThen\n\nx\n\nis a or of\n\nS\n\nif every neighbourhood of\n\nx\n\ncontains a point of\n\nS.\n\nNote that this definition does not depend upon whether neighbourhoods are required to be open.\n\nLimit point\n\nSee main article: Limit point.\n\nThe definition of a point of closure is closely related to the definition of a limit point. The difference between the two definitions is subtle but important – namely, in the definition of limit point, every neighbourhood of the point\n\nx\n\nin question must contain a point of the set . The set of all limit points of a set\n\nS\n\nis called the\n\nThus, every limit point is a point of closure, but not every point of closure is a limit point. A point of closure which is not a limit point is an isolated point. In other words, a point\n\nx\n\nis an isolated point of\n\nS\n\nif it is an element of\n\nS\n\nand if there is a neighbourhood of\n\nx\n\nwhich contains no other points of\n\nS\n\nother than\n\nx\n\nitself.\n\nFor a given set\n\nS\n\nand point\n\nx,\n\nx\n\nis a point of closure of\n\nS\n\nif and only if\n\nx\n\nis an element of\n\nS\n\nor\n\nx\n\nis a limit point of\n\nS\n\n(or both).\n\nClosure of a set\n\nThe of a subset\n\nS\n\nof a topological space\n\n(X,\\tau),\n\ndenoted by\n\n\\operatorname{cl}(X,S\n\nor possibly by\n\n\\operatorname{cl}XS\n\n(if\n\n\\tau\n\nis understood), where if both\n\nX\n\nand\n\n\\tau\n\nare clear from context then it may also be denoted by\n\n\\operatorname{cl}S,\n\n\\overline{S},\n\nor\n\nS{}-\n\n(moreover,\n\n\\operatorname{cl}\n\nis sometimes capitalized to\n\n\\operatorname{Cl}\n\n) can be defined using any of the following equivalent definitions:\n1. \\operatorname{cl}S\n\nis the set of all points of closure of\n\nS.\n\n2. \\operatorname{cl}S\n\nis the set\n\nS\n\ntogether with all of its limit points.\n3. \\operatorname{cl}S\n\nis the intersection of all closed sets containing\n\nS.\n\n4. \\operatorname{cl}S\n\nis the smallest closed set containing\n\nS.\n\n5. \\operatorname{cl}S\n\nis the union of\n\nS\n\nand its boundary\n\n\\partial(S).\n\n6. \\operatorname{cl}S\n\nis the set of all\n\nx\\inX\n\nfor which there exists a net (valued) in\n\nS\n\nthat converges to\n\nx\n\nin\n\n(X,\\tau).\n\nThe closure of a set has the following properties.\n\n\\operatorname{cl}S\n\nis a closed superset of\n\nS\n\n• The set\n\nS\n\nis closed if and only if\n\nS=\\operatorname{cl}S\n\n• If\n\nS\\subseteqT\n\nthen\n\n\\operatorname{cl}S\n\nis a subset of\n\n\\operatorname{cl}T.\n\n• If\n\nA\n\nis a closed set, then\n\nA\n\ncontains\n\nS\n\nif and only if\n\nA\n\ncontains\n\n\\operatorname{cl}S.\n\nSometimes the second or third property above is taken as the of the topological closure, which still make sense when applied to other types of closures (see below).\n\nIn a first-countable space (such as a metric space),\n\n\\operatorname{cl}S\n\nis the set of all limits of all convergent sequences of points in\n\nS.\n\nFor a general topological space, this statement remains true if one replaces \"sequence\" by \"net\" or \"filter\".\n\nNote that these properties are also satisfied if \"closure\", \"superset\", \"intersection\", \"contains/containing\", \"smallest\" and \"closed\" are replaced by \"interior\", \"subset\", \"union\", \"contained in\", \"largest\", and \"open\". For more on this matter, see closure operator below.\n\nExamples\n\nConsider a sphere in 3 dimensions. Implicitly there are two regions of interest created by this sphere; the sphere itself and its interior (which is called an open 3-ball). It is useful to be able to distinguish between the interior of 3-ball and the surface, so we distinguish between the open 3-ball, and the closed 3-ball – the closure of the 3-ball. The closure of the open 3-ball is the open 3-ball plus the surface.\n\n• In any space,\n\n\\varnothing=\\operatorname{cl}\\varnothing.\n\n• In any space\n\nX,\n\nX=\\operatorname{cl}X.\n\nGiving\n\nR\n\nand\n\nC\n\nthe standard (metric) topology:\n• If\n\nX\n\nis the Euclidean space\n\nR\n\nof real numbers, then\n\n\\operatorname{cl}X((0,1))=[0,1].\n\n• If\n\nX\n\nis the Euclidean space\n\nR\n\nthen the closure of the set\n\nQ\n\nof rational numbers is the whole space\n\nR.\n\nWe say that\n\nQ\n\nis dense in\n\nR.\n\n• If\n\nX\n\nis the complex plane\n\nC=R2,\n\nthen\n\n\\operatorname{cl}X\\left(\\{z\\inC:|z|>1\\}\\right)=\\{z\\inC:|z|\\geq1\\}.\n\n• If\n\nS\n\nis a finite subset of a Euclidean space\n\nX,\n\nthen\n\n\\operatorname{cl}XS=S.\n\n(For a general topological space, this property is equivalent to the T1 axiom.)\n\nOn the set of real numbers one can put other topologies rather than the standard one.\n\n• If\n\nX=R\n\nis endowed with the lower limit topology, then\n\n\\operatorname{cl}X((0,1))=[0,1).\n\n• If one considers on\n\nX=R\n\nthe discrete topology in which every set is closed (open), then\n\n\\operatorname{cl}X((0,1))=(0,1).\n\n• If one considers on\n\nX=R\n\nthe trivial topology in which the only closed (open) sets are the empty set and\n\nR\n\nitself, then\n\n\\operatorname{cl}X((0,1))=R.\n\nThese examples show that the closure of a set depends upon the topology of the underlying space. The last two examples are special cases of the following.\n\n• In any discrete space, since every set is closed (and also open), every set is equal to its closure.\n\nX,\n\nsince the only closed sets are the empty set and\n\nX\n\nitself, we have that the closure of the empty set is the empty set, and for every non-empty subset\n\nA\n\nof\n\nX,\n\n\\operatorname{cl}XA=X.\n\nIn other words, every non-empty subset of an indiscrete space is dense.\n\nThe closure of a set also depends upon in which space we are taking the closure. For example, if\n\nX\n\nis the set of rational numbers, with the usual relative topology induced by the Euclidean space\n\nR,\n\nand if\n\nS=\\{q\\inQ:q2>2,q>0\\},\n\nthen\n\nS\n\nis both closed and open in\n\nQ\n\nbecause neither\n\nS\n\nnor its complement can contain\n\n\\sqrt2\n\n, which would be the lower bound of\n\nS\n\n, but cannot be in\n\nS\n\nbecause\n\n\\sqrt2\n\nis irrational. So,\n\nS\n\nhas no well defined closure due to boundary elements not being in\n\nQ\n\n. However, if we instead define\n\nX\n\nto be the set of real numbers and define the interval in the same way then the closure of that interval is well defined and would be the set of all greater than\n\n\\sqrt2\n\n.\n\nClosure operator\n\nA on a set\n\nX\n\nis a mapping of the power set of\n\nX,\n\nl{P}(X)\n\n, into itself which satisfies the Kuratowski closure axioms. Given a topological space\n\n(X,\\tau)\n\n, the topological closure induces a function\n\n\\operatorname{cl}X:\\wp(X)\\to\\wp(X)\n\nthat is defined by sending a subset\n\nS\\subseteqX\n\nto\n\n\\operatorname{cl}XS,\n\nwhere the notation\n\n\\overline{S}\n\nor\n\nS-\n\nmay be used instead. Conversely, if\n\nc\n\nis a closure operator on a set\n\nX,\n\nthen a topological space is obtained by defining the closed sets as being exactly those subsets\n\nS\\subseteqX\n\nthat satisfy\n\nc(S)=S\n\n(so complements in\n\nX\n\nof these subsets form the open sets of the topology).\n\nThe closure operator\n\n\\operatorname{cl}X\n\nis dual to the interior operator, which is denoted by\n\n\\operatorname{int}X,\n\nin the sense that\n\n\\operatorname{cl}XS=X\\setminus\\operatorname{int}X(X\\setminusS),\n\nand also\n\n\\operatorname{int}XS=X\\setminus\\operatorname{cl}X(X\\setminusS).\n\nTherefore, the abstract theory of closure operators and the Kuratowski closure axioms can be readily translated into the language of interior operators by replacing sets with their complements in\n\nX.\n\nIn general, the closure operator does not commute with intersections. However, in a complete metric space the following result does hold:\n\nA subset\n\nS\n\nis closed in\n\nX\n\nif and only if\n\n\\operatorname{cl}XS=S.\n\nIn particular:\n• The closure of the empty set is the empty set;\n• The closure of\n\nX\n\nitself is\n\nX.\n\n• The closure of an intersection of sets is always a subset of (but need not be equal to) the intersection of the closures of the sets.\n• In a union of finitely many sets, the closure of the union and the union of the closures are equal; the union of zero sets is the empty set, and so this statement contains the earlier statement about the closure of the empty set as a special case.\n• The closure of the union of infinitely many sets need not equal the union of the closures, but it is always a superset of the union of the closures.\n\nIf\n\nS\\subseteqT\\subseteqX\n\nand if\n\nT\n\nis a subspace of\n\nX\n\n(meaning that\n\nT\n\nis endowed with the subspace topology that\n\nX\n\ninduces on it), then\n\n\\operatorname{cl}TS\\subseteq\\operatorname{cl}XS\n\nand the closure of\n\nS\n\ncomputed in\n\nT\n\nis equal to the intersection of\n\nT\n\nand the closure of\n\nS\n\ncomputed in\n\nX\n\n:\n\n\\operatorname{cl}TS~=~T\\cap\\operatorname{cl}XS.\n\n\n\nIn particular,\n\nS\n\nis dense in\n\nT\n\nif and only if\n\nT\n\nis a subset of\n\n\\operatorname{cl}XS.\n\nIf\n\nS,T\\subseteqX\n\nbut\n\nS\n\nis not necessarily a subset of\n\nT\n\nthen only\n\n\\operatorname{cl}T(S\\capT)~\\subseteq~T\\cap\\operatorname{cl}XS\n\nis guaranteed in general, where this containment could be strict (consider for instance\n\nX=\\R\n\nwith the usual topology,\n\nT=(-infty,0],\n\nand\n\nS=(0,infty)\n\n) although if\n\nT\n\nis an open subset of\n\nX\n\nthen the equality\n\n\\operatorname{cl}T(S\\capT)=T\\cap\\operatorname{cl}XS\n\nwill hold (no matter the relationship between\n\nS\n\nand\n\nT\n\n). Consequently, if\n\nl{U}\n\nis any open cover of\n\nX\n\nand if\n\nS\\subseteqX\n\nis any subset then:\n\n\\operatorname{cl}XS=cupU\n\n} \\operatorname_U (U \\cap S)\n\nbecause\n\n\\operatorname{cl}U(S\\capU)=U\\cap\\operatorname{cl}XS\n\nfor every\n\nU\\inl{U}\n\n(where every\n\nU\\inl{U}\n\nis endowed with the subspace topology induced on it by\n\nX\n\n). This equality is particularly useful when\n\nX\n\nis a manifold and the sets in the open cover\n\nl{U}\n\nare domains of coordinate charts. In words, this result shows that the closure in\n\nX\n\nof any subset\n\nS\\subseteqX\n\ncan be computed \"locally\" in the sets of any open cover of\n\nX\n\nand then unioned together.In this way, this result can be viewed as the analogue of the well-known fact that a subset\n\nS\\subseteqX\n\nis closed in\n\nX\n\nif and only if it is \"locally closed in\n\nX\n\n\", meaning that if\n\nl{U}\n\nis any open cover of\n\nX\n\nthen\n\nS\n\nis closed in\n\nX\n\nif and only if\n\nS\\capU\n\nis closed in\n\nU\n\nfor every\n\nU\\inl{U}.\n\nCategorical interpretation\n\nOne may elegantly define the closure operator in terms of universal arrows, as follows.\n\nThe powerset of a set\n\nX\n\nmay be realized as a partial order category\n\nP\n\nin which the objects are subsets and the morphisms are inclusion maps\n\nA\\toB\n\nwhenever\n\nA\n\nis a subset of\n\nB.\n\nFurthermore, a topology\n\nT\n\non\n\nX\n\nis a subcategory of\n\nP\n\nwith inclusion functor\n\nI:T\\toP.\n\nThe set of closed subsets containing a fixed subset\n\nA\\subseteqX\n\ncan be identified with the comma category\n\n(A\\downarrowI).\n\nThis category — also a partial order — then has initial object\n\n\\operatorname{cl}A.\n\nThus there is a universal arrow from\n\nA\n\nto\n\nI,\n\ngiven by the inclusion\n\nA\\to\\operatorname{cl}A.\n\nSimilarly, since every closed set containing\n\nX\\setminusA\n\ncorresponds with an open set contained in\n\nA\n\nwe can interpret the category\n\n(I\\downarrowX\\setminusA)\n\nas the set of open subsets contained in\n\nA,\n\nwith terminal object\n\n\\operatorname{int}(A),\n\nthe interior of\n\nA.\n\nAll properties of the closure can be derived from this definition and a few properties of the above categories. Moreover, this definition makes precise the analogy between the topological closure and other types of closures (for example algebraic closure), since all are examples of universal arrows.\n\nNotes and References\n\n1. , and use the second property as the definition.\n2. Because\n\n\\operatorname{cl}XS\n\nis a closed subset of\n\nX,\n\nthe intersection\n\nT\\cap\\operatorname{cl}XS\n\nis a closed subset of\n\nT\n\n(by definition of the subspace topology), which implies that\n\n\\operatorname{cl}TS\\subseteqT\\cap\\operatorname{cl}XS\n\n(because\n\n\\operatorname{cl}TS\n\nis the closed subset of\n\nT\n\ncontaining\n\nS\n\n). Because\n\nT\\cap\\operatorname{cl}XS\n\nis a closed subset of\n\nT,\n\nfrom the definition of the subspace topology, there must exist some set\n\nC\\subseteqX\n\nsuch that\n\nC\n\nis closed in\n\nX\n\nand\n\n\\operatorname{cl}TS=T\\capC.\n\nBecause\n\nS\\subseteq\\operatorname{cl}TS\\subseteqC\n\nand\n\nC\n\nis closed in\n\nX,\n\nthe minimality of\n\n\\operatorname{cl}XS\n\nimplies that\n\n\\operatorname{cl}XS\\subseteqC.\n\nIntersecting both sides with\n\nT\n\nshows that\n\nT\\cap\\operatorname{cl}XS\\subseteqT\\capC=\\operatorname{cl}TS.\n\n\\blacksquare\n\n3. From\n\nT:=(-infty,0\n\n4. Let\n\nS,T\\subseteqX\n\nand assume that\n\nT\n\nis open in\n\nX.\n\nLet\n\nC:=\\operatorname{cl}T(T\\capS),\n\nwhich is equal to\n\nT\\cap\\operatorname{cl}X(T\\capS)\n\n(because\n\nT\\capS\\subseteqT\\subseteqX\n\n). The complement\n\nT\\setminusC\n\nis open in\n\nT,\n\nwhere\n\nT\n\nbeing open in\n\nX\n\nnow implies that\n\nT\\setminusC\n\nis also open in\n\nX.\n\nConsequently\n\nX\\setminus(T\\setminusC)=(X\\setminusT)\\cupC\n\nis a closed subset of\n\nX\n\nwhere\n\n(X\\setminusT)\\cupC\n\ncontains\n\nS\n\nas a subset (because if\n\ns\\inS\n\nis in\n\nT\n\nthen\n\ns\\inT\\capS\\subseteq\\operatorname{cl}T(T\\capS)=C\n\n), which implies that\n\n\\operatorname{cl}XS\\subseteq(X\\setminusT)\\cupC.\n\nIntersecting both sides with\n\nT\n\nproves that\n\nT\\cap\\operatorname{cl}XS\\subseteqT\\capC=C.\n\nThe reverse inclusion follows from\n\nC\\subseteq\\operatorname{cl}X(T\\capS)\\subseteq\\operatorname{cl}XS.\n\n\\blacksquare"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.7067444,"math_prob":0.93707913,"size":6400,"snap":"2022-05-2022-21","text_gpt3_token_len":2191,"char_repetition_ratio":0.26626018,"word_repetition_ratio":0.0068965517,"special_character_ratio":0.25140625,"punctuation_ratio":0.11904762,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9979797,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-01-27T20:24:03Z\",\"WARC-Record-ID\":\"<urn:uuid:3cc730bd-b2d7-4283-929e-856e76db9273>\",\"Content-Length\":\"59802\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:7fa74a8a-03fb-4fbb-a4dc-f64cc67fcd11>\",\"WARC-Concurrent-To\":\"<urn:uuid:aa3106cb-ff60-4f87-8ef7-d192e801ea64>\",\"WARC-IP-Address\":\"85.25.210.18\",\"WARC-Target-URI\":\"https://everything.explained.today/Closure_(topology)/\",\"WARC-Payload-Digest\":\"sha1:454NWRM4JPCKUIKNTCFALI7ZVZMGAIES\",\"WARC-Block-Digest\":\"sha1:DUYV2BBEL5YEE3XEMG5INH5AIDRTEQBZ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-05/CC-MAIN-2022-05_segments_1642320305288.57_warc_CC-MAIN-20220127193303-20220127223303-00040.warc.gz\"}"} |
https://www.informatik.uni-kiel.de/~curry/listarchive/0142.html | [
"# Re: Puzzle\n\nFrom: Michael Hanus <hanus_at_informatik.rwth-aachen.de>\nDate: Tue, 1 Dec 1998 15:35:37 +0100\n\nDear Wolfgang,\n\nthanks for your interesting example. It shows that one has\nto be careful if there is too much syntactic sugar.\nMy initial motivation for the remark \"a defining equation f = g\nbetween functions will be interpreted in Curry as syntactic sugar\nfor the corresponding defining equation f x = g x on base types\"\nwas to express that the semantics of Curry is not based on\nhigher-order rewriting which might complicate things.\nThus, I assumed that this kind of desugaring is done\nafter lambda lifting. It might be interesting to note\nthat Haskell has also surprisingly restrictions.\nFor instance, the program\n\nf x = 1\nf x = 2\n\nis a valid Haskell program, whereas the version\n\nf = \\x->1\nf = \\x->2\n\nseems to be invalid (although Hugs accepts currently both).\n\nYour remark reminds me that I wanted to suggest a further\nrestriction for local pattern definitions in Curry which solves\nthese problems:\n\nAll variables occurring in lhs patterns in some let/where\nshould occur at most once in a lhs of a local pattern declaration.\n\nThis restriction would forbid programs like\n\nf x = coin where coin = 1\ncoin = 2"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.91382134,"math_prob":0.91390336,"size":1304,"snap":"2023-40-2023-50","text_gpt3_token_len":319,"char_repetition_ratio":0.08846154,"word_repetition_ratio":0.0,"special_character_ratio":0.24156442,"punctuation_ratio":0.08949416,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9692447,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-12-01T02:54:08Z\",\"WARC-Record-ID\":\"<urn:uuid:32e57ad9-ef92-4b8f-a41e-e8dc672df9e0>\",\"Content-Length\":\"7237\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:f63dd7f4-4c5d-43ff-88e8-2e8c116f5426>\",\"WARC-Concurrent-To\":\"<urn:uuid:ca0133c8-30ac-42d9-aa25-e0048bff6730>\",\"WARC-IP-Address\":\"134.245.248.185\",\"WARC-Target-URI\":\"https://www.informatik.uni-kiel.de/~curry/listarchive/0142.html\",\"WARC-Payload-Digest\":\"sha1:JY52QEVOSKTLYZFDTO2YBZFDTB3NB7EM\",\"WARC-Block-Digest\":\"sha1:ONWY6F2ZGD6SIKLPEYI42R7DMEFQICST\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-50/CC-MAIN-2023-50_segments_1700679100264.9_warc_CC-MAIN-20231201021234-20231201051234-00444.warc.gz\"}"} |
https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Book%3A_Quantum_States_of_Atoms_and_Molecules_(Zielinksi_et_al.)/10%3A_Theories_of_Electronic_Molecular_Structure/10.0S%3A_10.S%3A_Theories_of_Electronic_Molecular_Structure_(Summary) | [
"# 10.S: Theories of Electronic Molecular Structure (Summary)\n\nOther terms account for the interactions between all the magnetic dipole moments and the interactions with any external electric or magnetic fields. The charge distribution of an atomic nucleus is not always spherical and, when appropriate, this asymmetry must be taken into account as well as the relativistic effect that a moving electron experiences as a change in mass. This complete Hamiltonian is too complicated and is not needed for many situations. In practice, only the terms that are essential for the purpose at hand are included. Consequently in the absence of external fields, interest in spin-spin and spin-orbit interactions, and in electron and nuclear magnetic resonance spectroscopy (ESR and NMR), the molecular Hamiltonian usually is considered to consist only of the kinetic and potential energy terms, and the Born-Oppenheimer approximation is made in order to separate the nuclear and electronic motion.\n\nIn general, electronic wavefunctions for molecules are constructed from approximate one-electron wavefunctions. These one-electron functions are called molecular orbitals. The expectation value expression for the energy is used to optimize these functions, i.e. make them as good as possible. The criterion for quality is the energy of the ground state. According to the Variational Principle, an approximate ground state energy always is higher than the exact energy, so the best energy in a series of approximations is the lowest energy. In this chapter we describe how the variational method, perturbation theory, the self-consistent field method, and configuration interaction all are used to describe the electronic states of molecules. The ultimate goal is a mathematical description of electrons in molecules that enables chemists and other scientists to develop a deep understanding of chemical bonding, to calculate properties of molecules, and to make predictions based on these calculations. For example, an active area of research in industry involves calculating changes in chemical properties of pharmaceutical drugs as a result of changes in their chemical structure.\n\nStudy Guide\n\n• What is meant by the expression ab initio calculation?\n• List all the terms in a complete molecular Hamiltonian.\n• Why are calculations on closed-shell systems more easily done than on open-shell systems?\n• How is it possible to reduce a multi-electron Hamiltonian operator to a single-electron Fock operator?\n• Why is the calculation with the Fock operator called a self-consistent field calculation?\n• What is the physical meaning of a SCF one-electron energy?\n• Why is the nonlinear variational method not used in every case to optimize basis functions, and what usually is done instead?\n• Why is it faster for a computer to use the variational principle to determine the coefficients in a linear combination of functions than to determine the parameters in the functions?\n• Identify the characteristics of hydrogenic, Slater, and Gaussian basis sets.\n• What is meant by the Hartree-Fock wavefunction and energy?\n• What is the difference between a restricted and unrestricted Hartree-Fock calculation?\n• What is neglected that makes the Hartree-Fock energy necessarily greater than the exact energy?\n• What is meant by correlation energy?\n• What purpose is served by including configuration interaction in a calculation?"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9239626,"math_prob":0.96149075,"size":3566,"snap":"2019-51-2020-05","text_gpt3_token_len":679,"char_repetition_ratio":0.13054463,"word_repetition_ratio":0.0073937154,"special_character_ratio":0.1805945,"punctuation_ratio":0.09166667,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9748172,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-01-26T03:14:49Z\",\"WARC-Record-ID\":\"<urn:uuid:e42da2b0-0f1f-4350-8cec-f52aec91434e>\",\"Content-Length\":\"86019\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:faf34fa5-9af5-4d85-9600-bbc0df9ca645>\",\"WARC-Concurrent-To\":\"<urn:uuid:24c61003-89c5-4b7e-9856-37c789f5f155>\",\"WARC-IP-Address\":\"99.84.181.53\",\"WARC-Target-URI\":\"https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Book%3A_Quantum_States_of_Atoms_and_Molecules_(Zielinksi_et_al.)/10%3A_Theories_of_Electronic_Molecular_Structure/10.0S%3A_10.S%3A_Theories_of_Electronic_Molecular_Structure_(Summary)\",\"WARC-Payload-Digest\":\"sha1:WPKMW32JHGRTHTQWSESV2RTSP6RMVYVF\",\"WARC-Block-Digest\":\"sha1:TPVBO5NDHPWH4GMBYVBNQCZLBCNXPGQH\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-05/CC-MAIN-2020-05_segments_1579251684146.65_warc_CC-MAIN-20200126013015-20200126043015-00152.warc.gz\"}"} |
https://en.wikipedia.org/wiki/Riemann_surface | [
"# Riemann surface",
null,
"Riemann surface for the function f(z) = z. The two horizontal axes represent the real and imaginary parts of z, while the vertical axis represents the real part of z. The imaginary part of z is represented by the coloration of the points. For this function, it is also the height after rotating the plot 180° around the vertical axis.\n\nIn mathematics, particularly in complex analysis, a Riemann surface is a connected one-dimensional complex manifold. These surfaces were first studied by and are named after Bernhard Riemann. Riemann surfaces can be thought of as deformed versions of the complex plane: locally near every point they look like patches of the complex plane, but the global topology can be quite different. For example, they can look like a sphere or a torus or several sheets glued together.\n\nThe main interest in Riemann surfaces is that holomorphic functions may be defined between them. Riemann surfaces are nowadays considered the natural setting for studying the global behavior of these functions, especially multi-valued functions such as the square root and other algebraic functions, or the logarithm.\n\nEvery Riemann surface is a two-dimensional real analytic manifold (i.e., a surface), but it contains more structure (specifically a complex structure) which is needed for the unambiguous definition of holomorphic functions. A two-dimensional real manifold can be turned into a Riemann surface (usually in several inequivalent ways) if and only if it is orientable and metrizable. So the sphere and torus admit complex structures, but the Möbius strip, Klein bottle and real projective plane do not.\n\nGeometrical facts about Riemann surfaces are as \"nice\" as possible, and they often provide the intuition and motivation for generalizations to other curves, manifolds or varieties. The Riemann–Roch theorem is a prime example of this influence.\n\n## Definitions\n\nThere are several equivalent definitions of a Riemann surface.\n\n1. A Riemann surface X is a connected complex manifold of complex dimension one. This means that X is a connected Hausdorff space that is endowed with an atlas of charts to the open unit disk of the complex plane: for every point xX there is a neighbourhood of x that is homeomorphic to the open unit disk of the complex plane, and the transition maps between two overlapping charts are required to be holomorphic.\n2. A Riemann surface is an oriented manifold of (real) dimension two – a two-sided surface – together with a conformal structure. Again, manifold means that locally at any point x of X, the space is homeomorphic to a subset of the real plane. The supplement \"Riemann\" signifies that X is endowed with an additional structure which allows angle measurement on the manifold, namely an equivalence class of so-called Riemannian metrics. Two such metrics are considered equivalent if the angles they measure are the same. Choosing an equivalence class of metrics on X is the additional datum of the conformal structure.\n\nA complex structure gives rise to a conformal structure by choosing the standard Euclidean metric given on the complex plane and transporting it to X by means of the charts. Showing that a conformal structure determines a complex structure is more difficult.\n\n## Examples\n\n• The complex plane C is the most basic Riemann surface. The map f(z) = z (the identity map) defines a chart for C, and {f} is an atlas for C. The map g(z) = z* (the conjugate map) also defines a chart on C and {g} is an atlas for C. The charts f and g are not compatible, so this endows C with two distinct Riemann surface structures. In fact, given a Riemann surface X and its atlas A, the conjugate atlas B = {f* : f ∈ A} is never compatible with A, and endows X with a distinct, incompatible Riemann structure.\n• In an analogous fashion, every non-empty open subset of the complex plane can be viewed as a Riemann surface in a natural way. More generally, every non-empty open subset of a Riemann surface is a Riemann surface.\n• Let S = C ∪ {∞} and let f(z) = z where z is in S \\ {∞} and g(z) = 1 / z where z is in S \\ {0} and 1/∞ is defined to be 0. Then f and g are charts, they are compatible, and { fg } is an atlas for S, making S into a Riemann surface. This particular surface is called the Riemann sphere because it can be interpreted as wrapping the complex plane around the sphere. Unlike the complex plane, it is compact.\n• The theory of compact Riemann surfaces can be shown to be equivalent to that of projective algebraic curves that are defined over the complex numbers and non-singular. For example, the torus C/(Z + τ Z), where τ is a complex non-real number, corresponds, via the Weierstrass elliptic function associated to the lattice Z + τ Z, to an elliptic curve given by an equation\ny2 = x3 + a x + b.\n\nTori are the only Riemann surfaces of genus one; surfaces of higher genera g are provided by the hyperelliptic surfaces\n\ny2 = P(x),\nwhere P is a complex polynomial of degree 2g + 1.\n• All compact Riemann surfaces are algebraic curves since they can be embedded into some $\\mathbb {CP} ^{n}$",
null,
". This follows from the Kodaira embedding theorem and the fact there exists a positive line bundle on any complex curve.\n• Important examples of non-compact Riemann surfaces are provided by analytic continuation.\n\n## Further definitions and properties\n\nAs with any map between complex manifolds, a function f: MN between two Riemann surfaces M and N is called holomorphic if for every chart g in the atlas of M and every chart h in the atlas of N, the map hfg−1 is holomorphic (as a function from C to C) wherever it is defined. The composition of two holomorphic maps is holomorphic. The two Riemann surfaces M and N are called biholomorphic (or conformally equivalent to emphasize the conformal point of view) if there exists a bijective holomorphic function from M to N whose inverse is also holomorphic (it turns out that the latter condition is automatic and can therefore be omitted). Two conformally equivalent Riemann surfaces are for all practical purposes identical.\n\n### Orientability\n\nEach Riemann surface, being a complex manifold, is orientable as a real manifold. For complex charts f and g with transition function h = f(g−1(z)), h can be considered as a map from an open set of R2 to R2 whose Jacobian in a point z is just the real linear map given by multiplication by the complex number h'(z). However, the real determinant of multiplication by a complex number α equals |α|2, so the Jacobian of h has positive determinant. Consequently, the complex atlas is an oriented atlas.\n\n### Functions\n\nEvery non-compact Riemann surface admits non-constant holomorphic functions (with values in C). In fact, every non-compact Riemann surface is a Stein manifold.\n\nIn contrast, on a compact Riemann surface X every holomorphic function with values in C is constant due to the maximum principle. However, there always exist non-constant meromorphic functions (holomorphic functions with values in the Riemann sphere C ∪ {∞}). More precisely, the function field of X is a finite extension of C(t), the function field in one variable, i.e. any two meromorphic functions are algebraically dependent. This statement generalizes to higher dimensions, see Siegel (1955). Meromorphic functions can be given fairly explicitly, in terms of Riemann theta functions and the Abel–Jacobi map of the surface.\n\n## Analytic vs. algebraic\n\nThe existence of non-constant meromorphic functions can be used to show that any compact Riemann surface is a projective variety, i.e. can be given by polynomial equations inside a projective space. Actually, it can be shown that every compact Riemann surface can be embedded into complex projective 3-space. This is a surprising theorem: Riemann surfaces are given by locally patching charts. If one global condition, namely compactness, is added, the surface is necessarily algebraic. This feature of Riemann surfaces allows one to study them with either the means of analytic or algebraic geometry. The corresponding statement for higher-dimensional objects is false, i.e. there are compact complex 2-manifolds which are not algebraic. On the other hand, every projective complex manifold is necessarily algebraic, see Chow's theorem.\n\nAs an example, consider the torus T := C/(Z + τ Z). The Weierstrass function $\\wp _{\\tau }(z)$",
null,
"belonging to the lattice Z + τ Z is a meromorphic function on T. This function and its derivative $\\wp _{\\tau }'(z)$",
null,
"generate the function field of T. There is an equation\n\n$[\\wp '(z)]^{2}=4[\\wp (z)]^{3}-g_{2}\\wp (z)-g_{3},$",
null,
"where the coefficients g2 and g3 depend on τ, thus giving an elliptic curve Eτ in the sense of algebraic geometry. Reversing this is accomplished by the j-invariant j(E), which can be used to determine τ and hence a torus.\n\n## Classification of Riemann surfaces\n\nThe set of all Riemann surfaces can be divided into three subsets: hyperbolic, parabolic and elliptic Riemann surfaces. Geometrically, these correspond to surfaces with negative, vanishing or positive constant sectional curvature. That is, every connected Riemann surface $X$",
null,
"admits a unique complete 2-dimensional real Riemann metric with constant curvature equal to $-1,0$",
null,
"or $1$",
null,
"which belongs to the conformal class of Riemannian metrics determined by its structure as a Riemann surface. This can be seen as a consequence of the existence of isothermal coordinates.\n\nIn complex analytic terms, the Poincaré–Koebe uniformization theorem (a generalization of the Riemann mapping theorem) states that every simply connected Riemann surface is conformally equivalent to one of the following:\n\n• The Riemann sphere ${\\widehat {\\mathbf {C} }}:=\\mathbf {C} \\cup \\{\\infty \\}$",
null,
", which is isomorphic to the $\\mathbf {P} ^{1}(\\mathbf {C} )$",
null,
";\n• The complex plane $\\mathbf {C}$",
null,
";\n• The open disk $\\mathbf {D} :=\\{z\\in \\mathbf {C} :|z|<1\\}$",
null,
"which is isomorphic to the upper half-plane $\\mathbf {H} :=\\{z\\in \\mathbf {C} :\\mathrm {Im} (z)>0\\}$",
null,
".\n\nA Riemann surface is elliptic, parabolic or hyperbolic according to whether its universal cover is isomorphic to $\\mathbf {P} ^{1}(\\mathbf {C} )$",
null,
", $\\mathbf {C}$",
null,
"or $\\mathbf {D}$",
null,
". The elements in each class admit a more precise description.\n\n### Elliptic Riemann surfaces\n\nThe Riemann sphere $\\mathbf {P} ^{1}(\\mathbf {C} )$",
null,
"is the only example, as there is no group acting on it by biholomorphic transformations freely and properly discontinuously and so any Riemann surface whose universal cover is isomorphic to $\\mathbf {P} ^{1}(\\mathbf {C} )$",
null,
"must itself be isomorphic to it.\n\n### Parabolic Riemann surfaces\n\nIf $X$",
null,
"is a Riemann surface whose universal cover is isomorphic to the complex plane $\\mathbf {C}$",
null,
"then it is isomorphic to one of the following surfaces:\n\n• $\\mathbf {C}$",
null,
"itself;\n• The quotient $\\mathbf {C} /\\mathbf {Z}$",
null,
";\n• A quotient $\\mathbf {C} /(\\mathbf {Z} +\\mathbf {Z} \\tau )$",
null,
"where $\\tau \\in \\mathbf {C}$",
null,
"with $\\mathrm {Im} (\\tau )>0$",
null,
".\n\nTopologically there are only three types: the plane, the cylinder and the torus. But while in the two former case the (parabolic) Riemann surface structure is unique, varying the parameter $\\tau$",
null,
"in the third case gives non-isomorphic Riemann surfaces. The description by the parameter $\\tau$",
null,
"gives the Teichmüller space of \"marked\" Riemann surfaces (in addition to the Riemann surface structure one adds the topological data of a \"marking\", which can be seen as a fixed homeomorphism to the torus). To obtain the analytic moduli space (forgetting the marking) one takes the quotient of Teichmüller space by the mapping class group. In this case it is the modular curve.\n\n### Hyperbolic Riemann surfaces\n\nIn the remaining cases $X$",
null,
"is a hyperbolic Riemann surface, that is isomorphic to a quotient of the upper half-plane by a Fuchsian group (this is sometimes called a Fuchsian model for the surface). The topological type of $X$",
null,
"can be any orientable surface save the torus and sphere.\n\nA case of particular interest is when $X$",
null,
"is compact. Then its topological type is described by its genus $g\\geq 2$",
null,
". Its Teichmüller space and moduli space are $6g-6$",
null,
"-dimensional. A similar classification of Riemann surfaces of finite type (that is homeomorphic to a closed surface minus a finite number of points) can be given. However in general the moduli space of Riemann surfaces of infinite topological type is too large to admit such a description.\n\n## Maps between Riemann surfaces\n\nThe geometric classification is reflected in maps between Riemann surfaces, as detailed in Liouville's theorem and the Little Picard theorem: maps from hyperbolic to parabolic to elliptic are easy, but maps from elliptic to parabolic or parabolic to hyperbolic are very constrained (indeed, generally constant!). There are inclusions of the disc in the plane in the sphere: $\\Delta \\subset \\mathbf {C} \\subset {\\widehat {\\mathbf {C} }},$",
null,
"but any holomorphic map from the sphere to the plane is constant, any holomorphic map from the plane into the unit disk is constant (Liouville's theorem), and in fact any holomorphic map from the plane into the plane minus two points is constant (Little Picard theorem)!\n\n### Punctured spheres\n\nThese statements are clarified by considering the type of a Riemann sphere ${\\widehat {\\mathbf {C} }}$",
null,
"with a number of punctures. With no punctures, it is the Riemann sphere, which is elliptic. With one puncture, which can be placed at infinity, it is the complex plane, which is parabolic. With two punctures, it is the punctured plane or alternatively annulus or cylinder, which is parabolic. With three or more punctures, it is hyperbolic – compare pair of pants. One can map from one puncture to two, via the exponential map (which is entire and has an essential singularity at infinity, so not defined at infinity, and misses zero and infinity), but all maps from zero punctures to one or more, or one or two punctures to three or more are constant.\n\n### Ramified covering spaces\n\nContinuing in this vein, compact Riemann surfaces can map to surfaces of lower genus, but not to higher genus, except as constant maps. This is because holomorphic and meromorphic maps behave locally like $z\\mapsto z^{n},$",
null,
"so non-constant maps are ramified covering maps, and for compact Riemann surfaces these are constrained by the Riemann–Hurwitz formula in algebraic topology, which relates the Euler characteristic of a space and a ramified cover.\n\nFor example, hyperbolic Riemann surfaces are ramified covering spaces of the sphere (they have non-constant meromorphic functions), but the sphere does not cover or otherwise map to higher genus surfaces, except as a constant.\n\n## Isometries of Riemann surfaces\n\nThe isometry group of a uniformized Riemann surface (equivalently, the conformal automorphism group) reflects its geometry:\n\n• genus 0 – the isometry group of the sphere is the Möbius group of projective transforms of the complex line,\n• the isometry group of the plane is the subgroup fixing infinity, and of the punctured plane is the subgroup leaving invariant the set containing only infinity and zero: either fixing them both, or interchanging them (1/z).\n• the isometry group of the upper half-plane is the real Möbius group; this is conjugate to the automorphism group of the disk.\n• genus 1 – the isometry group of a torus is in general translations (as an Abelian variety), though the square lattice and hexagonal lattice have addition symmetries from rotation by 90° and 60°.\n• For genus g ≥ 2, the isometry group is finite, and has order at most 84(g − 1), by Hurwitz's automorphisms theorem; surfaces that realize this bound are called Hurwitz surfaces.\n• It is known that every finite group can be realized as the full group of isometries of some Riemann surface.\n• For genus 2 the order is maximized by the Bolza surface, with order 48.\n• For genus 3 the order is maximized by the Klein quartic, with order 168; this is the first Hurwitz surface, and its automorphism group is isomorphic to the unique simple group of order 168, which is the second-smallest non-abelian simple group. This group is isomorphic to both PSL(2,7) and PSL(3,2).\n• For genus 4, Bring's surface is a highly symmetric surface.\n• For genus 7 the order is maximized by the Macbeath surface, with order 504; this is the second Hurwitz surface, and its automorphism group is isomorphic to PSL(2,8), the fourth-smallest non-abelian simple group.\n\n## Function-theoretic classification\n\nThe classification scheme above is typically used by geometers. There is a different classification for Riemann surfaces which is typically used by complex analysts. It employs a different definition for \"parabolic\" and \"hyperbolic\". In this alternative classification scheme, a Riemann surface is called parabolic if there are no non-constant negative subharmonic functions on the surface and is otherwise called hyperbolic. This class of hyperbolic surfaces is further subdivided into subclasses according to whether function spaces other than the negative subharmonic functions are degenerate, e.g. Riemann surfaces on which all bounded holomorphic functions are constant, or on which all bounded harmonic functions are constant, or on which all positive harmonic functions are constant, etc.\n\nTo avoid confusion, call the classification based on metrics of constant curvature the geometric classification, and the one based on degeneracy of function spaces the function-theoretic classification. For example, the Riemann surface consisting of \"all complex numbers but 0 and 1\" is parabolic in the function-theoretic classification but it is hyperbolic in the geometric classification."
] | [
null,
"https://upload.wikimedia.org/wikipedia/commons/thumb/9/9c/Riemann_sqrt.svg/310px-Riemann_sqrt.svg.png",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/2f02cfe21a83e074d5589b15f2e5f0947cb39c4d",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/0b7906cd754770b5fdbcdf47696755df0cd4bcd4",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/b13aa27846469ee752b04ccd1e5907256cf8b1a7",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/d094adcb0b3a44c6e5cbdc747eef133ab81f4d67",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/68baa052181f707c662844a465bfeeb135e82bab",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/2ecc0cf14129eadc29034c37c3514979e9a22f62",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/92d98b82a3778f043108d4e20960a9193df57cbf",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/1b3d280946e51d275323d5a180ebe4b942dcc809",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/b8ad36aa52f587ebbcbdd22ef95ca901faca2fa6",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/11de80478fce9090e43eed19100b37cc841661e8",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/d11e41499bdeebe9e1f48b674cbbcc12f26ffc62",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/2d0e2311d8977de4df7778accdec9edf89630d2e",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/b8ad36aa52f587ebbcbdd22ef95ca901faca2fa6",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/11de80478fce9090e43eed19100b37cc841661e8",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/b2345293072878db24e119c580def49ad582e3ed",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/b8ad36aa52f587ebbcbdd22ef95ca901faca2fa6",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/b8ad36aa52f587ebbcbdd22ef95ca901faca2fa6",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/68baa052181f707c662844a465bfeeb135e82bab",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/11de80478fce9090e43eed19100b37cc841661e8",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/11de80478fce9090e43eed19100b37cc841661e8",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/58cb76df9aeb82f73e84d16713eb070c8ea1f99c",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/ffb5fdb97b250079933e4d5d60531cca138eb2ad",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/76285b74a5fec2dc9cfd715f46c6ab2489033708",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/e776b45526b3f635dcb3485280e7b8f32692663a",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/68baa052181f707c662844a465bfeeb135e82bab",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/68baa052181f707c662844a465bfeeb135e82bab",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/68baa052181f707c662844a465bfeeb135e82bab",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/b84b2394f64ae9927e09ee51b848be213edecafe",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/66916d4a8725d7a8ef883852a69a351f2a8b5ccc",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/587a538fa8d1e02f5037e0fa573b6a6eb0603c78",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/e2bca04fcef2ebdc939432dd69095376e5a1397f",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/e816921d9adb44252accd58f444cca827a5ab262",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8663973,"math_prob":0.984755,"size":19334,"snap":"2023-14-2023-23","text_gpt3_token_len":4669,"char_repetition_ratio":0.17263322,"word_repetition_ratio":0.03356142,"special_character_ratio":0.22369918,"punctuation_ratio":0.1228169,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99838,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70],"im_url_duplicate_count":[null,8,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,9,null,9,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,9,null,9,null,9,null,10,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-06-09T19:36:35Z\",\"WARC-Record-ID\":\"<urn:uuid:35fce45c-0749-4582-a5bb-30ef6128610c>\",\"Content-Length\":\"193094\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:5e197b69-8ceb-4000-beae-1ac098af3790>\",\"WARC-Concurrent-To\":\"<urn:uuid:042073d2-91f4-4319-8aaf-ea612e2e6bf5>\",\"WARC-IP-Address\":\"208.80.154.224\",\"WARC-Target-URI\":\"https://en.wikipedia.org/wiki/Riemann_surface\",\"WARC-Payload-Digest\":\"sha1:75XIGBYJTAEBDKYVMASC4PUO5EKQH75A\",\"WARC-Block-Digest\":\"sha1:PJ2QWCCRSY46U73OY4BMBK2OXCQPGYV3\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-23/CC-MAIN-2023-23_segments_1685224656788.77_warc_CC-MAIN-20230609164851-20230609194851-00744.warc.gz\"}"} |
https://eng.kakprosto.ru/how-242383-how-to-calculate-average-wage | [
"You will need\n• settlement statements for the three months of the employee;\n• - production calendar;\n• calculator;\n• - HR documents employee.\nInstruction\n1\nUse the settlement statements for preceding three months of dismissal of the employee. Fold his wages for the period. Enable this amount of salary, bonuses, allowances and other payments that are remuneration for the performance of his official duties, spelled out in the agreement (contract). Do not include in the calculation of the cash issued to an employee as financial assistance or a lump sum.\n2\nNow the sum of the number of working days in the last three months of employment of the employee. To do this, use the production calendar. Then calculate the number of days worked in the period.\n3\nFind the value of the average daily wage of a specialist. To do this, divide the amount of payments on the actual number of days worked.\n4\nThen determine the average number of working days. The actual number of days worked, divide by three.\n5\nAfter that the average daily earnings of an employee, multiply by the average number of days worked in a month. Thus, to get the average wage of an employee. This value will be used for the calculation and accrual of unemployment benefits.\n6\nIf you need to calculate the average wage for the calculation of sickness benefit or vacation pay, the calculation will be made in the same way. The difference lies in the following. The billing period is twelve calendar months. Payments for performance of duties for the year are summarized. Then calculated the average daily wage by dividing total earnings by the number of calendar days in the year. The obtained value is multiplied by 29.5 days.\n7\nWhen filling out the reference to the employment center please note that the document contains graphs in which you need to specify the number of days of sick leave, vacation, if any."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9312381,"math_prob":0.97260046,"size":1875,"snap":"2023-14-2023-23","text_gpt3_token_len":378,"char_repetition_ratio":0.15499733,"word_repetition_ratio":0.0062111802,"special_character_ratio":0.20266667,"punctuation_ratio":0.10335196,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9601221,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-06-09T21:19:56Z\",\"WARC-Record-ID\":\"<urn:uuid:8802ee12-70b3-478d-acad-c17163f5d10b>\",\"Content-Length\":\"33108\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:8e020816-b00f-4e1a-b407-1027936be37b>\",\"WARC-Concurrent-To\":\"<urn:uuid:1828741c-6a91-481d-b314-cdbe8fa928bd>\",\"WARC-IP-Address\":\"178.154.246.3\",\"WARC-Target-URI\":\"https://eng.kakprosto.ru/how-242383-how-to-calculate-average-wage\",\"WARC-Payload-Digest\":\"sha1:UPDETR5JWYOFFNKCLEVLBD3MHE6BRLD5\",\"WARC-Block-Digest\":\"sha1:4437Z5LTIKML7UDOGFSGE3RVDKYTQI5L\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-23/CC-MAIN-2023-23_segments_1685224656833.99_warc_CC-MAIN-20230609201549-20230609231549-00534.warc.gz\"}"} |
https://bloginonline.com/diagram-of-a-typical-bone/diagram-of-a-typical-bone-diagram-of-a-typical-long-bone-anatomical-diagram-of-typical-long/ | [
"# Diagram Of A Typical Bone Diagram Of A Typical Long Bone Anatomical Diagram Of Typical Long\n\nDiagram Of A Typical Bone Diagram Of A Typical Long Bone Anatomical Diagram Of Typical Long",
null,
"Tagged: a well labelled diagram of a typical long bone, diagram of a typical bone, diagram of a typical long bone, draw a labelled diagram of a typical long bone, draw and label a diagram of a typical bone, labeled diagram of the structure of a typical long bone, structure of a typical bone diagram"
] | [
null,
"https://bloginonline.com/wp-content/uploads/2018/07/diagram-of-a-typical-bone-diagram-of-a-typical-long-bone-anatomical-diagram-of-typical-long.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.62901187,"math_prob":0.9147955,"size":1508,"snap":"2019-51-2020-05","text_gpt3_token_len":312,"char_repetition_ratio":0.37367022,"word_repetition_ratio":0.37269372,"special_character_ratio":0.19363396,"punctuation_ratio":0.028571429,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.97503364,"pos_list":[0,1,2],"im_url_duplicate_count":[null,1,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-12-15T07:20:12Z\",\"WARC-Record-ID\":\"<urn:uuid:b7ce2b63-76e5-4f5a-b257-e4a1c5294575>\",\"Content-Length\":\"58433\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:9a0a2a5a-f9ce-4aae-ac31-a51863eceb8b>\",\"WARC-Concurrent-To\":\"<urn:uuid:4bc1fe6a-b977-4bd8-961b-2f188c9c794f>\",\"WARC-IP-Address\":\"145.239.7.237\",\"WARC-Target-URI\":\"https://bloginonline.com/diagram-of-a-typical-bone/diagram-of-a-typical-bone-diagram-of-a-typical-long-bone-anatomical-diagram-of-typical-long/\",\"WARC-Payload-Digest\":\"sha1:4Q7ZG3VMXYF5JO24FCKDYAVYRLG5ALCH\",\"WARC-Block-Digest\":\"sha1:2WUSBIQ5QEKUEPI2TNKIL6N73KQPL5HF\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-51/CC-MAIN-2019-51_segments_1575541307797.77_warc_CC-MAIN-20191215070636-20191215094636-00355.warc.gz\"}"} |
https://betterlesson.com/lesson/425905/working-with-expressions-and-equations-part-3?from=breadcrumb_lesson | [
"# Working with Expressions and Equations Part 3\n\n15 teachers like this lesson\nPrint Lesson\n\n## Objective\n\nSWBAT: ⢠Create algebraic expressions and equations based on word problems. ⢠Use substitution to evaluate algebraic expressions.\n\n#### Big Idea\n\nBenâs mom gives him the option of grooming 3 horses or mowing 2 fields. Which job should Ben choose? Why? Students use their knowledge of algebraic expressions and equations to write expressions and equations.\n\n## Do Now\n\n7 minutes\n\nPart of my class routine is a do now at the beginning of every class. Students walk into class and pick up the packet for the day. They get to work quickly on the problems. Often, I create do nows that have problems that connect to the task that students will be working on that day. For this lesson I want students to start thinking about expressions that involve more than one operation.\n\nI ask for a volunteer to read number 1. I assert that I think that the answer is a. 8h + 2. I tell students to discuss my answer with their neighbor and decide whether they agree or disagree. I can on a few students to explain their thinking. I want students to articulate that a. would be correct if it cost \\$2 to enter and \\$8 for every extra hour. For number 3 I ask students to identify one answer choice that is incorrect and explain why it does not work. Why might a student choose that answer choice?\n\n## Guided Practice\n\n7 minutes\n\nAfter the Do Now, I have a student read the objectives for the day. I tell students that they will again be creating expressions and equations to model situations. These expressions and equations will be more complicated than the ones that we created previously.\n\nBefore students move into groups, we work through page 2 together. I ask students who has ever ridden a horse before. Students share out what they know about horses and we look at the picture about the tools that you need in order to groom, or clean, a horse.\n\nWe read #1 and I call on a student to share his/her answer. If the student gives me 90 minutes, I ask for another way to write that answer (1 ½ hours or 1.5 hours). How long would it take him to group 2 horses? 4? 9? Using that data, I ask students to write an expression that shows how many minutes it will take Ben to groom h horses and to create an expression that is equivalent. I want students to articulate that since it takes 30 minutes to groom each horse, you need to multiply the number of horses he grooms by 30 minutes and the order does not matter.\n\nStudents will be working in groups of 3-4 students on the rest of the packet. I will review group expectations and using the Group Work Rubric. See the Using the Group Work Rubric video in my Strategy Folder.\n\n## Group Work\n\n31 minutes\n\nI walk around and monitor student progress and fill out the group work rubric for each group. I am also looking for student work that has different strategies for solving #4 on page 5 to use during the closure.\n\nSome common mistakes are students incorrectly using substitution with the expression they have created. Some students also get confused with number 6 on page 4, since both chores will take the same amount of time. If students are struggling with pages 3-4, I may ask them the following questions:\n\n• What is going on in this situation?\n• How long would it take if he/she needed to groom 10 horses? What operation did you use to figure that out?\n• How many unknowns are in the situation?\n• What does your answer mean? What units belong with your answer? Could you write the answer in another way?\n\nSome students may struggle when they get to the “Making Money” questions on page 5 and 6. Here are some questions I may ask:\n\n• How many minutes are in an hour?\n• How much does he make for 1 hour of work? How can you use that information to help you?\n• How many hours did it take Ben to complete that chore?\n\nFor students who correctly work through problems I may ask them these questions and then have them work on the substitution practice on page 7:\n\n• Would Ben make more money grooming 11 horses or mowing 8 fields? How do you know?\n• How much money would Ben earn if he mowed 3 ½ fields?\n• Ben has 4 ½ hours, how many fields can he mow?\n\n## Closure and Ticket to Go\n\n15 minutes\n\nI ask students to share and compare their answers to question 6 on page 6. I want students to articulate that it doesn’t matter which chore he chooses, each of them will take 2 hours to complete. Then we’ll move on to talk about #4 on page 5. I will call up the students I identified during the group work time to put their work under the document camera and explain their thinking. Some students may use equivalent rates to show that if he earns \\$6/1 hour than he’ll earn \\$15/2 ½ hours of work. Other students may start with the rate \\$6/60 minutes and go from there. Other student may create a unit rate that \\$1/10 minutes and use that to find the amount of money Ben earns. Other students may use go through a similar process but not use rates. Some students will use decimals. If I did not see students using some of these strategies I will model them under the document camera.\n\nI will ask whether I could change 150 minutes --> 2 hours 30 minutes --> 2.3 hours to use in my calculations. I want students to be able to articulate that 2 hours and 30 minutes is not equivalent to 2.3 hours, since an hour is out of 60 minutes, so 30 minutes represents 30/60 or ½ or .5.\n\nIf I have time, I ask students to share struggles they had and how they overcame them. I also ask students if there are still struggles they are having. I ask other students to give advice. In my classroom I try to consistently show students that they will struggle with different problems but that they need to use their creative problem solving minds to try a strategy. If that strategy doesn’t work, try another one! The main question in this lesson was a difficult one that required students to problem solve and persevere through challenges and set-backs. I want to acknowledge my students hard work and their persistence.\n\nWith 5 minutes remaining, pass out the ticket to go. Students work independently to complete it."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.96570885,"math_prob":0.6255729,"size":4864,"snap":"2019-35-2019-39","text_gpt3_token_len":1063,"char_repetition_ratio":0.15884773,"word_repetition_ratio":0.008908686,"special_character_ratio":0.22327302,"punctuation_ratio":0.07947686,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9535845,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-08-26T05:55:00Z\",\"WARC-Record-ID\":\"<urn:uuid:3194cbd6-abea-439a-b0b9-aa3b4f3e60dc>\",\"Content-Length\":\"143842\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:f2fb2849-ffff-4cea-9b10-70424314fd60>\",\"WARC-Concurrent-To\":\"<urn:uuid:b5d36c5b-8c04-44a6-8789-953d81a269a1>\",\"WARC-IP-Address\":\"107.21.10.124\",\"WARC-Target-URI\":\"https://betterlesson.com/lesson/425905/working-with-expressions-and-equations-part-3?from=breadcrumb_lesson\",\"WARC-Payload-Digest\":\"sha1:LYKPFN6QQWYNM5DCLFZZRIY3ASUR7IC2\",\"WARC-Block-Digest\":\"sha1:ZIT5RCU7OX2AVYTWMTZYMKAZHVAK367R\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-35/CC-MAIN-2019-35_segments_1566027330968.54_warc_CC-MAIN-20190826042816-20190826064816-00547.warc.gz\"}"} |
https://refractiveindex.info/?shelf=main&book=AgGaSe2&page=Boyd-e | [
"# RefractiveIndex.INFO\n\nRefractive index database\n\nShelf\n\nBook\n\nPage\n\n## Optical constants of AgGaSe2 (Silver gallium selenide, AGSe)Boyd et al. 1972: n(e) 0.725–13.5 µm\n\nWavelength: µm\n(0.725 – 13.5)\n\n### Complex refractive index (n+ik)[ i ]\n\nn k LogX LogY eV\n\n### Dispersion formula [ i ]\n\n$$n^2-1=4.2912+\\frac{1.3970λ^2}{λ^2-0.2845}+\\frac{1.9282λ^2}{λ^2-1600}$$\n\nExtraordinary ray(e)\n\n### References\n\n1) G. D. Boyd, H. M. Kasper, J. H McFee, F. G Storz. Linear and nonlinear optical properties of some ternary selenides, IEEE J. Quant. Electron., 8, 900-908 (1972)\n2) G. C. Bhar, Refractive index interpolation in phase-matching, Appl. Opt. 15, 305-307 (1976)\n*Ref. 2 provides a dispersion formula based on data from Ref. 1"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.5535143,"math_prob":0.91295236,"size":657,"snap":"2022-40-2023-06","text_gpt3_token_len":251,"char_repetition_ratio":0.07810107,"word_repetition_ratio":0.0,"special_character_ratio":0.3850837,"punctuation_ratio":0.23125,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9831254,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-09-28T11:46:46Z\",\"WARC-Record-ID\":\"<urn:uuid:3de00029-b4e0-4114-b140-061267af1587>\",\"Content-Length\":\"37660\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:292c9800-734e-49b8-8055-511f35e2eb25>\",\"WARC-Concurrent-To\":\"<urn:uuid:9019a275-f745-4cb3-81e5-0b835bcdf67f>\",\"WARC-IP-Address\":\"50.63.7.197\",\"WARC-Target-URI\":\"https://refractiveindex.info/?shelf=main&book=AgGaSe2&page=Boyd-e\",\"WARC-Payload-Digest\":\"sha1:RWFIVTVKCAJ6RXFZOOCXZMTWY4BCJTAE\",\"WARC-Block-Digest\":\"sha1:JTZ7BMXKC6QMHT6Z32H6FKXPSUCDGJ55\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-40/CC-MAIN-2022-40_segments_1664030335254.72_warc_CC-MAIN-20220928113848-20220928143848-00783.warc.gz\"}"} |
https://carafilms.com/mastering-linear-regression-a-step-by-step-guide/ | [
"# Mastering Linear Regression: A Step-By-Step Guide\n\nAre you ready to become a master of linear regression? If you’re looking to gain a deep understanding of this powerful statistical technique, then you’ve come to the right place.\n\nIn this step-by-step guide, we will walk you through the process of mastering linear regression, helping you to build a solid foundation and develop the skills needed to confidently apply it to your own data analysis projects.\n\nLinear regression is a fundamental tool in statistics and machine learning, allowing you to model the relationship between a dependent variable and one or more independent variables. It provides a way to make predictions, understand the strength of relationships, and identify the most important factors influencing the outcome.\n\nBy mastering linear regression, you will unlock the ability to uncover valuable insights from your data and make informed decisions based on evidence. Whether you’re a beginner or have some experience with linear regression, this guide will equip you with the knowledge and practical skills needed to excel in this field.\n\nSo, let’s dive in and take your understanding of linear regression to new heights!\n\n## Understanding the Basics of Linear Regression\n\nSo, you’re ready to dive into the world of linear regression? Let’s start by understanding the basics and wrap our heads around this popular statistical technique.\n\nLinear regression is a powerful tool used to analyze the relationship between two variables. It helps you predict the value of a dependent variable based on the values of one or more independent variables.\n\nThe main idea behind linear regression is to find the best-fitting line that represents the relationship between these variables. This line is determined by minimizing the sum of the squared differences between the predicted values and the actual values of the dependent variable. By doing so, linear regression allows you to make predictions and understand the impact of the independent variables on the dependent variable.\n\nTo get started with linear regression, you need to have a clear understanding of the key components involved. The dependent variable, also known as the response variable, is the variable you want to predict or explain using the independent variables.\n\nOn the other hand, the independent variables, also known as predictor variables, are the variables used to predict the value of the dependent variable. It’s important to note that linear regression assumes a linear relationship between the independent variables and the dependent variable. This means that the relationship can be represented by a straight line on a scatter plot.\n\nBy understanding these basics, you can begin to grasp the foundations of linear regression and move towards mastering this essential statistical technique.\n\n## Defining Dependent and Independent Variables\n\nTo define your dependent and independent variables, picture yourself as a researcher identifying the factors that influence a particular outcome. The dependent variable is the outcome or the variable that you’re trying to predict or explain. It’s the variable that you believe is influenced by one or more independent variables.\n\nFor example, if you’re studying the effect of temperature on plant growth, the dependent variable would be the growth of the plants. In this case, temperature would be the independent variable as it’s believed to have an effect on the growth of the plants.\n\nThe independent variables, on the other hand, are the variables that you believe have an effect on the dependent variable. These variables are usually manipulated or controlled by the researcher to observe their impact on the dependent variable.\n\nIn the plant growth example, the independent variable would be the temperature. Other independent variables that could be considered include the amount of sunlight, the type of soil, or the amount of water provided to the plants.\n\nBy defining your dependent and independent variables clearly, you can set up your study in a way that allows you to analyze the relationship between them and make predictions or explanations based on your findings.\n\n## Assumptions and Types of Linear Regression Models\n\nLinear regression models make certain assumptions about the relationship between the dependent and independent variables, and understanding these assumptions is crucial for accurate analysis and interpretation of the data.\n\nThe first assumption is linearity, which means that there is a linear relationship between the dependent variable and the independent variable(s). This assumption implies that as the independent variable(s) change, the dependent variable changes in a constant and predictable manner. If this assumption is violated, the results of the linear regression model may not be reliable.\n\nThe second assumption is independence, which means that the observations in the dataset are independent of each other. This assumption is important because if the observations are not independent, it can lead to biased and inefficient estimates. To check for independence, it is important to ensure that there is no systematic pattern or correlation in the residuals, which are the differences between the observed and predicted values of the dependent variable.\n\nAnother assumption is homoscedasticity, which means that the variance of the residuals is constant across all levels of the independent variable(s). If this assumption is violated, it indicates that the spread of the residuals is not consistent, and it can lead to unreliable estimates and incorrect inferences. To check for homoscedasticity, one can plot the residuals against the predicted values and look for any patterns or trends.\n\nLastly, the assumption of normality states that the residuals follow a normal distribution. This assumption is important because many statistical tests and confidence intervals rely on the assumption of normality. Violation of this assumption can lead to incorrect p-values and confidence intervals.\n\nOverall, understanding the assumptions and types of linear regression models is crucial for accurate analysis and interpretation of data. Violation of these assumptions can lead to biased and unreliable results, so it’s important to check for them and consider alternative models if necessary.\n\n## Step 1: Data Collection and Cleaning\n\nCollecting and cleaning data is the first exciting step in building a successful linear regression model. It involves gathering all the necessary data points and ensuring that they’re accurate and reliable.\n\nYou start by identifying the variables that are relevant to your model and collecting data for each of them. This may involve conducting surveys, performing experiments, or extracting data from existing sources.\n\nOnce you’ve collected the data, you need to clean it by removing any errors, outliers, or missing values. This is crucial because using flawed data can lead to inaccurate and unreliable results. Cleaning the data involves techniques such as imputation, where missing values are estimated and replaced, and outlier detection, where extreme values are identified and either corrected or removed.\n\nThe process of data cleaning also includes checking for inconsistencies, such as duplicate entries or contradictory information. It’s important to ensure that all the data is in the same format and follows the same conventions. This may require converting data types, standardizing units of measurement, or merging datasets.\n\nAdditionally, it’s crucial to validate the data by cross-checking it with known values or independent sources. This helps to identify any potential errors or discrepancies.\n\nBy meticulously collecting and cleaning your data, you lay the foundation for a robust and reliable linear regression model. It ensures that your analysis is based on accurate and trustworthy information, leading to more meaningful insights and better predictions.\n\n## Step 2: Model Building and Evaluation\n\nOnce you’ve gathered and cleaned your data, it’s time to start building and evaluating your model to uncover valuable insights and make accurate predictions. The first step in model building is to select the appropriate variables for your regression analysis. This involves identifying the independent variables that are most likely to have an impact on the dependent variable you’re trying to predict.\n\nIt’s important to consider the theoretical and practical significance of each variable and ensure they’re relevant to your research question.\n\nAfter selecting the variables, you can start building your regression model. There are various techniques and algorithms available, but a common approach is to use the ordinary least squares (OLS) method. This method minimizes the sum of squared residuals to find the best-fitting line that represents the relationship between the independent and dependent variables.\n\nOnce the model is built, you can evaluate its performance by assessing the goodness of fit. This can be done by analyzing the R-squared value, which indicates the proportion of the variance in the dependent variable that’s explained by the independent variables. Additionally, you can examine the p-values of the coefficients to determine if they’re statistically significant. A low p-value suggests that the coefficient has a significant impact on the dependent variable.\n\nBy carefully evaluating your model, you can ensure its accuracy and reliability, allowing you to make informed decisions and predictions based on the insights gained from the regression analysis.\n\n### What are some common challenges faced during the data collection and cleaning process in linear regression?\n\nSome common challenges you may face during the data collection and cleaning process in linear regression include missing values, outliers, data inconsistencies, and dealing with large datasets.\n\n### How can we handle missing data in linear regression analysis?\n\nTo handle missing data in linear regression analysis, you can use techniques like imputation, where missing values are filled in based on other variables, or you can remove the incomplete cases from the analysis.\n\n### Are there any specific techniques or methods to deal with outliers in linear regression?\n\nTo handle outliers in linear regression, you can use techniques like removing outliers based on statistical tests, transforming variables, or using robust regression methods. These methods help improve the accuracy of the regression analysis.\n\n### What are some common evaluation metrics used to assess the performance of a linear regression model?\n\nCommon evaluation metrics used to assess linear regression models include mean squared error, mean absolute error, root mean squared error, and R-squared. These metrics help you measure how well the model fits the data and make comparisons between different models.\n\n### How can multicollinearity affect the results of a linear regression analysis and how can it be addressed?\n\nMulticollinearity can distort the results of a linear regression analysis by making it difficult to determine the independent effects of predictor variables. It can be addressed by removing correlated variables or using techniques like principal component analysis.\n\n## Conclusion\n\nSo there you have it, a step-by-step guide to mastering linear regression. By understanding the basics of linear regression and the importance of defining dependent and independent variables, you’re well on your way to becoming a pro in this field.\n\nAdditionally, by familiarizing yourself with the assumptions and types of linear regression models, you can choose the most suitable approach for your data.\n\nThe key to success lies in thorough data collection and cleaning, followed by model building and evaluation. This process ensures that your model is accurate and reliable.\n\nWith practice and dedication, you’ll become proficient in mastering linear regression and be able to confidently apply it to various real-world scenarios.\n\nSo go ahead, take the plunge, and start your journey towards becoming a linear regression expert!"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9060462,"math_prob":0.9049163,"size":11985,"snap":"2023-40-2023-50","text_gpt3_token_len":2086,"char_repetition_ratio":0.19288874,"word_repetition_ratio":0.0413679,"special_character_ratio":0.17046309,"punctuation_ratio":0.08787432,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98242915,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-12-07T22:37:19Z\",\"WARC-Record-ID\":\"<urn:uuid:1141d720-358a-4a1f-9b6c-fa4cffb59ecd>\",\"Content-Length\":\"66407\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:49655865-de66-473c-99ea-a21c363948da>\",\"WARC-Concurrent-To\":\"<urn:uuid:a7f0f73f-5e9c-463f-87a2-d333a1044fed>\",\"WARC-IP-Address\":\"172.67.150.147\",\"WARC-Target-URI\":\"https://carafilms.com/mastering-linear-regression-a-step-by-step-guide/\",\"WARC-Payload-Digest\":\"sha1:BDKHYBUOHF35UG7MORJHKN3ZOVDZKFXG\",\"WARC-Block-Digest\":\"sha1:MQG4UPREB2KUTZ4EWBCRTQSZTY7SJM6V\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-50/CC-MAIN-2023-50_segments_1700679100705.19_warc_CC-MAIN-20231207221604-20231208011604-00128.warc.gz\"}"} |
https://meangreenmath.com/category/popular-culture/page/2/ | [
"# Predicate Logic and Popular Culture (Part 237): Psycho\n\nLet",
null,
"$P$ be the set of all people, let",
null,
"$T$ be the set of all times, and let",
null,
"$M(x,t)$ be the statement “",
null,
"$x$ goes mad at time",
null,
"$t$.” Translate the logical statement",
null,
"$\\forall x \\in P \\exists t \\in T (\\sim M(x,t))$.\n\nThis matches a line from the movie Psycho.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 236): Dirty Dancing\n\nLet",
null,
"$P$ be the set of all people, and let",
null,
"$C(x)$ be the statement “",
null,
"$x$ puts Baby in a corner.” Translate the logical statement",
null,
"$\\forall x \\in P (\\sim C(x))$.\n\nThis matches a line from the movie Dirty Dancing.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 235): Suits\n\nLet",
null,
"$p$ be the statement “Winners make excuses,” and let",
null,
"$q$ be the statement “The other side plays the game.” Translate the logical statement",
null,
"$q Rightarrow \\sim p$.\n\nThis matches a line from the TV show Suits.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 234): Linkin Park\n\nLet",
null,
"$p$ be the statement “They turn down the lights,” and let",
null,
"$q$ be the statement “I hear my battle symphony.” Translate the logical statement",
null,
"$p \\Rightarrow q$.\n\nThis matches part of the chorus of “Battle Symphony” by Linkin Park.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 233): Panic! At The Disco\n\nLet",
null,
"$F(x)$ be the statement “",
null,
"$x$ feels good,” let",
null,
"$H(x)$ be the statement “",
null,
"$x$ tastes good,” let",
null,
"$M(x)$ be the statement “",
null,
"$x$ is mine,” and let",
null,
"$H$ be the set of all things. Translate the logical statement",
null,
"$\\forall x \\in H( (F(x) \\land H(x)) \\Rightarrow M(x))$.\n\nThis matches a line from “Emperor’s New Clothes” by Panic! At The Disco.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 232): Limp Bizkit\n\nLet",
null,
"$B(x)$ be the statement “",
null,
"$x$ knows what it’s like to be the bad man,” let",
null,
"$H(x)$ be the statement “",
null,
"$x$ knows what it’s like to be hated,” and let",
null,
"$P$ be the set of all people. Translate the logical statement",
null,
"$\\forall x \\in P(\\lnot B(x) \\land \\lnot H(x))$.\n\nThis matches the opening lines of “Behind Blue Eyes” by Limp Bizkit.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 231): Aristocats\n\nLet",
null,
"$C(x)$ be the statement “",
null,
"$x$ wants to be a cat,” and let",
null,
"$P$ be the set of all people. Translate the logical statement",
null,
"$\\forall x in P(C(x))$.\n\nThis matches the opening line of “Everyone Wants to be a Cat” from the movie “The Aristocats.”\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 230): Dean Lewis\n\nLet",
null,
"$W(t)$ be the statement “It is easy to walk away at time",
null,
"$t$,” and let",
null,
"$T$ be the set of all times. Translate the logical statement",
null,
"$\\forall t \\in T(\\lnot W(t))$.\n\nThis matches part of the chorus of “Be Alright” by Dean Lewis.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 229): Mean Girls\n\nLet",
null,
"$W(t)$ be the statement “",
null,
"$t$ is a Wednesday,” let",
null,
"$P(t)$ be the statement “We wear pink at time",
null,
"$t$,” and let",
null,
"$T$ be the set of all times. Translate the logical statement",
null,
"$\\forall t \\in T(W(t) \\Rightarrow P(t))$.\n\nThis matches a line from the movie “Mean Girls.”\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first.\n\n# Predicate Logic and Popular Culture (Part 228): Hannah Montana\n\nLet",
null,
"$M(x)$ be the statement “",
null,
"$x$ makes mistakes,” let",
null,
"$D(x)$ be the statement “",
null,
"$x$ has those days,” and let",
null,
"$P$ be the set of all people. Translate the logical statement",
null,
"$\\forall x \\in P(M(x) \\land D(x))$.\n\nThis matches the opening lines of “Nobody’s Perfect” by Hannah Montana.\n\nContext: Part of the discrete mathematics course includes an introduction to predicate and propositional logic for our math majors. As you can probably guess from their names, students tend to think these concepts are dry and uninteresting even though they’re very important for their development as math majors.\n\nIn an effort to making these topics more appealing, I spent a few days mining the depths of popular culture in a (likely futile) attempt to make these ideas more interesting to my students. In this series, I’d like to share what I found. Naturally, the sources that I found have varying levels of complexity, which is appropriate for students who are first learning prepositional and predicate logic.\n\nWhen I actually presented these in class, I either presented the logical statement and had my class guess the statement in actual English, or I gave my students the famous quote and them translate it into predicate logic. However, for the purposes of this series, I’ll just present the statement in predicate logic first."
] | [
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null,
"https://s0.wp.com/latex.php",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9564396,"math_prob":0.6713906,"size":12416,"snap":"2022-40-2023-06","text_gpt3_token_len":2433,"char_repetition_ratio":0.14413472,"word_repetition_ratio":0.8879847,"special_character_ratio":0.19434601,"punctuation_ratio":0.093534485,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9629157,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-10-01T05:11:50Z\",\"WARC-Record-ID\":\"<urn:uuid:ebbc3d4f-bed7-4716-b10e-6f31d7efd205>\",\"Content-Length\":\"148467\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:ce2a7653-8170-4ba4-a828-f3be4a44b652>\",\"WARC-Concurrent-To\":\"<urn:uuid:6ed6fc52-01fd-443c-b393-96270a69b911>\",\"WARC-IP-Address\":\"192.0.78.24\",\"WARC-Target-URI\":\"https://meangreenmath.com/category/popular-culture/page/2/\",\"WARC-Payload-Digest\":\"sha1:IOWG6MGBT73GH7DDQUIN2ZJQHZJQOAOW\",\"WARC-Block-Digest\":\"sha1:GFSQVKJGL4H3OFCIIHL6SBK5ACFGEO6H\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-40/CC-MAIN-2022-40_segments_1664030335530.56_warc_CC-MAIN-20221001035148-20221001065148-00669.warc.gz\"}"} |
https://www.nagwa.com/en/videos/748137847924/ | [
"# Video: Determining the Definite Integral of a Trigonometric Function\n\nDetermine ∫_(−𝜋) ^(−𝜋/4) 8 cos 5𝜃 d𝜃.\n\n04:50\n\n### Video Transcript\n\nDetermine the integral of eight cos five 𝜃 d𝜃 between negative 𝜋 by four and negative 𝜋.\n\nOur first step here is to take out the constant eight. This leaves us with eight multiplied by the integral of cos five 𝜃 d𝜃. The integral of cos 𝜃 is a standard one that we should know. It is equal to sin 𝜃, as integrating is the opposite, or inverse, of differentiating.\n\nWe want to integrate cos five 𝜃. This means we need to use another general rule. This states that the integral of cos 𝑛𝜃 is equal to one over 𝑛 multiplied by sin 𝜃. We differentiate the 𝑛𝜃 to give us 𝑛. The integral of cos five 𝜃 is equal to one-fifth multiplied by sin five 𝜃. We need to multiply this by eight and have limits of negative 𝜋 by four and negative 𝜋. As with the eight at the start, we can take the constant one-fifth outside of the bracket. This gives us eight-fifths multiplied by sin five 𝜃.\n\nOur next step is to substitute in our two limits and subtract the answers. Substituting in the upper limit gives us sin of five multiplied by negative 𝜋 over four. This can be rewritten as sin of negative five 𝜋 over four. Substituting in our lower limit gives us sin of five multiplied by negative 𝜋. Once again, this can be rewritten as sin of negative five 𝜋.\n\nAt this point, it is worth drawing the sine curve to see if negative five 𝜋 by four and negative five 𝜋 correspond with any our known angles. The sine curve has a maximum value of one and a minimum value of negative one. It has key values on the 𝜃-, or 𝑥-axis, of 𝜋 by two and 𝜋, negative 𝜋 by two and negative 𝜋. If you prefer to think of these angles in degrees. It’s worth remembering that 𝜋 radians is equal to 180 degrees.\n\nThe sine curve looks as shown in the diagram. However, at the moment, we have a slight problem as our two angles negative five 𝜋 by four and negative five 𝜋 don’t fit in the range. As the sine curve has a period of two 𝜋, it repeats every two 𝜋 radians, we can continue the graph as shown.\n\nWe can see clearly from the graph that the sin of negative five 𝜋 is equal to zero. Negative five 𝜋 by four is shown in the diagram. By going vertically upwards to the sine curve and then horizontally along to the 𝑦-axis, we can see what this value will take. Due to the symmetry of the sine curse, sin of negative five 𝜋 by four is equal to sin of 𝜋 by four.\n\n𝜋 by four is equal to 45 degrees and is one of our known angles. This is equal to root two over two. The sin of 45 degrees equals root two over two. Therefore, the sin of 𝜋 by four radians must also equal root two over two. The sin of negative five 𝜋 by four is equal to root two over two. And the sin of negative five 𝜋 is equal to zero.\n\nRoot two over two minus zero is root two over two. So, we need to multiply this by eight-fifths. Multiplying the numerators gives us eight root two. And multiplying the denominators, gives us 10. We have eight root two over 10. Eight and 10 have a common factor of two. So, we can divide the numerator and denominator by two. This gives us four root two over five. We can, therefore, say that the integral of eight cos five 𝜃 d𝜃 between negative 𝜋 by four and negative 𝜋 is equal to four root two over five."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9327611,"math_prob":0.9968589,"size":3176,"snap":"2020-45-2020-50","text_gpt3_token_len":894,"char_repetition_ratio":0.1793821,"word_repetition_ratio":0.16242038,"special_character_ratio":0.22638538,"punctuation_ratio":0.09348442,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99968016,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-10-22T11:26:27Z\",\"WARC-Record-ID\":\"<urn:uuid:c54b4209-38e1-4ee9-8f68-bb5864c06cb2>\",\"Content-Length\":\"29399\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:44f32aaf-3362-4552-89f7-64fc02af3f3e>\",\"WARC-Concurrent-To\":\"<urn:uuid:3275d99d-2306-4c3e-adba-c86a87116a6f>\",\"WARC-IP-Address\":\"23.23.60.1\",\"WARC-Target-URI\":\"https://www.nagwa.com/en/videos/748137847924/\",\"WARC-Payload-Digest\":\"sha1:VAT25YWXSMW5SMCTLBAJUAUCMC4ZWA47\",\"WARC-Block-Digest\":\"sha1:FBEHRGKZBDAPLBGDPI2RRUK47CUZ4P6A\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-45/CC-MAIN-2020-45_segments_1603107879537.28_warc_CC-MAIN-20201022111909-20201022141909-00319.warc.gz\"}"} |
https://www.npmjs.com/package/geometric-pack | [
"# npm\n\n## geometric-pack",
null,
"0.7.1 • Public • Published\n\n# Geometric pack\n\nGeometric calculator created with TypeScript\n\nThe package supports accuracy up to 12 decimal places.\n\n## General info\n\nGeometric pack with lots of available calculations for 2D and 3D geometry\n\n## Example\n\n```import { Triangle } from \"geometric-pack\";\n\nconst firstTriangle = new Triangle(5, 3, 4);\nconst secondTriangle = new Triangle(10, 6, 8);\n\nconsole.log(firstTriangle.isCongruent(secondTriangle)); // False\nconsole.log(firstTriangle.isSimilar(secondTriangle)); // True```\n\nYou can also check more examples by running `.getDefinition()` method on other classes or by running example file\n\n``````\\$ node node_modules/geometric-pack/dist/utils/example\n``````\n\n## Launch\n\nTo use available calculations in this project you will have to create object of class you want to use and start available methods\n\n```import { Triangle } from \"geometric-pack\";\n\nconst firstTriangle = new Triangle(5, 3, 4);\n\nconsole.log(firstTriangle.getDefinition());\n\n// returns:\n// {\n// sideLengthA: 3,\n// sideLengthB: 4,\n// sideLengthC: 5,\n// circumference: 12,\n// area: 6,\n// rightAngle: true,\n// heights: { heightOfBaseA: 4, heightOfBaseB: 3, heightOfBaseC: 2.4 },\n// angles: { gamma: 90, beta: 53.13010235415598, alpha: 36.86989764584402 },\n// }```\n\nAvailable classes:\n\n• Two-dimensional\n\n• `Triangle`, You have to use three arguments and program will take them as a sides of triangle 'a', 'b', 'c', you can write them in any order you want because program will sort them a < b < c\n\n• `Rectangle`, You have to use two arguments and program will take them as a sides of rectangle 'a', 'b', program will not sort them in any order\n\n• `Square`, You have to use one argument and program will take it as a side of square 'a'\n\n• `Circle`, You have to use one argument and program will take it as a radius of circle 'r'\n\n• `Rhombus`, You have to use two arguments and program will take them as side 'a' and height 'h' in exact order\n\n• `Parallelogram`, You have to use three arguments and program will take them as side 'a', side 'b' and height 'h' in exact order\n\n• `Polygon`, It's a regular polygon so you have to use two arguments and program will take them as side 'a' and number of sides 'n' where 3 <= n <= 14 in exact order\n\n• `Stadium`, You have to use two arguments and program will take them as side length 'a' and radius 'r' in exact order\n\n• `Distance2D`, You have to use four arguments and program will take them as coordinates 'x1', 'y1', 'x2', 'y2' in exact order\n\n• `Annulus`, You have to use two arguments and program will take them as outerRadius 'r1' and innerRadius 'r2' in exact order\n\n• `QuadraticFunction`, You have two use three arguments and program will take them as 'a', 'b' and 'c' of function in exact order\n\n• `LinearFunction`, You have to use two arguments and program will take them as 'a' and 'b' of function in exact order\n\n• Three-dimensional\n\n• `Cone`, You have to use two arguments and program will take them as radius 'r' and height 'h' in exact order\n\n• `Cylinder`, You have to use two arguments and program will take them as radius 'r' and height 'h' in exact order\n\n• `Sphere`, You have to use one argument and program will take it as radius 'r'\n\n• `Cube`, You have to use one argument and program will take it as length side 'a'\n\n• `ConicalFrustum`, You have to use three arguments and program will take them as radius1 'r1', radius2 'r2' and height 'h' in exact order\n\n• `Capsule`, You have to use two arguments and program will take them as sideLength 'a' and radius 'r' in exact order\n\n• `Hemisphere`, You have to use two one argument and program will take it as radius 'r'\n\n• `Pyramid`, You have to use two arguments and program will take them as side length 'a' and height 'h' in exact order\n\n• `Cuboid`, You have to use three arguments and program will take them as length 'l', width 'w' and height 'h' in exact order\n\n• `Distance3D`, You have to use six arguments and program will take them as coordinates 'x1', 'y1', 'z1', 'x2', 'y2', 'z2' in exact order\n\n• `Tube`, You have to use three arguments and program will take them as outerRadius 'r1', innerRadius 'r2' and height 'h' in exact order\n\n## Setup\n\nTo run this project, install it locally using npm\n\n``````\\$ cd ../lorem\n\\$ npm init\n\\$ npm i geometric-pack\n``````\n\n## Technologies\n\nProject is created with:\n\n• TypeScript: 4.3.5\n\n### Install\n\n`npm i geometric-pack`\n\n### Repository\n\ngithub.com/MateuszCaputa/geometric-pack\n\n### Homepage\n\ngithub.com/MateuszCaputa/geometric-pack\n\n8\n\n0.7.1"
] | [
null,
"https://static.npmjs.com/255a118f56f5346b97e56325a1217a16.svg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8205311,"math_prob":0.5723987,"size":4220,"snap":"2023-14-2023-23","text_gpt3_token_len":1119,"char_repetition_ratio":0.23197344,"word_repetition_ratio":0.372442,"special_character_ratio":0.2729858,"punctuation_ratio":0.1299505,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98632306,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-05-30T16:12:27Z\",\"WARC-Record-ID\":\"<urn:uuid:46e33d5a-3768-4a46-a3e9-6bd340151703>\",\"Content-Length\":\"109024\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:47de06bb-1441-4c21-8d95-f25cbf62acef>\",\"WARC-Concurrent-To\":\"<urn:uuid:eef405b4-d66b-4791-8940-9e9600e3aa98>\",\"WARC-IP-Address\":\"104.16.93.83\",\"WARC-Target-URI\":\"https://www.npmjs.com/package/geometric-pack\",\"WARC-Payload-Digest\":\"sha1:3UAZVRP4TVP5OES5FBLK43PH6JJB7FGR\",\"WARC-Block-Digest\":\"sha1:G6BK2MRVBJK2T7GH37MXTBJNBDKC5XPC\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-23/CC-MAIN-2023-23_segments_1685224645810.57_warc_CC-MAIN-20230530131531-20230530161531-00669.warc.gz\"}"} |
https://utzx.com/units/convert-30-inches-to-cm/ | [
"# Convert 30 Inches to CM\n\n## How much are 1 inch equivalent to cm?\n\ncminchesconverter is an efficient converter tool that can help you achieve inches to cm conversion.\n\nWe all know that centimeters and inches are the units used to measure length.\n\nBefore you can convert the ratio of 30 inches in cm, you need to know one inch is equivalent to how much cm.\n\nCentimeters or centimetres are the measurement unit for length measurement used in the metric system. English symbols are abbreviated by the letter cm. The meter is defined internationally as an SI unit, but the centimeter does not. One cm is equivalent to one hundredth of meter. It’s also approximately 39.37 in.\n\n## What is Inch?\n\nAn Anglo-American measure for length is the inch (its symbol is in).. Its symbol is in. In many European local languages, “inch” can be utilized interchangeably with “thumb” or from “thumb”. Since a person’s thumb is about an inch wide.\n\n• Electronic components, for example, the dimensions of the PC screen.\n• Dimensions of tires for cars and trucks.\n\n## How to Transfer 30 inches in centimeters?\n\nThe formula can be utilized to solve any problem from in to cm.\n\nWe can directly apply the formula to convert 30 inch to cm.\n\n1 inch = 2.54 cm\n\nHere is an example to help you in understanding this more.30 inches to cm= 2.54 × 30 = 76.2 cm.\n\n inches cm 29.6 inches 75.184 cm 29.65 inches 75.311 cm 29.7 inches 75.438 cm 29.75 inches 75.565 cm 29.8 inches 75.692 cm 29.85 inches 75.819 cm 29.9 inches 75.946 cm 29.95 inches 76.073 cm 30 inches 76.2 cm 30.05 inches 76.327 cm 30.1 inches 76.454 cm 30.15 inches 76.581 cm 30.2 inches 76.708 cm 30.25 inches 76.835 cm 30.3 inches 76.962 cm 30.35 inches 77.089 cm"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8652728,"math_prob":0.9718311,"size":1706,"snap":"2023-40-2023-50","text_gpt3_token_len":498,"char_repetition_ratio":0.18448883,"word_repetition_ratio":0.0,"special_character_ratio":0.33352873,"punctuation_ratio":0.15696202,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.95891684,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-12-03T17:49:51Z\",\"WARC-Record-ID\":\"<urn:uuid:322d9c9b-b542-4ab8-9cc8-ad981edab785>\",\"Content-Length\":\"136710\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:6c2a902f-2f3e-40d5-9056-c869ba0a0639>\",\"WARC-Concurrent-To\":\"<urn:uuid:408d29c0-369f-4e47-a323-6e36130721f8>\",\"WARC-IP-Address\":\"172.67.212.217\",\"WARC-Target-URI\":\"https://utzx.com/units/convert-30-inches-to-cm/\",\"WARC-Payload-Digest\":\"sha1:PSHPMWAIOSO6JJWB6RG2GWZ2DAZKMQRM\",\"WARC-Block-Digest\":\"sha1:GH3CIGMDGM57HH32IVSHUPYSEVNTXF2S\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-50/CC-MAIN-2023-50_segments_1700679100508.42_warc_CC-MAIN-20231203161435-20231203191435-00269.warc.gz\"}"} |
http://ylamifeb.blog.free.fr/index.php?post/2020/05/29/Download-ebooks-for-ipad-2-The-Math-Book%3A-Big-Ideas-Simply-Explained | [
"## The Math Book: Big Ideas Simply Explained by DK",
null,
"",
null,
"• The Math Book: Big Ideas Simply Explained\n• DK\n• Page: 352\n• Format: pdf, ePub, mobi, fb2\n• ISBN: 9781465480248\n• Publisher: DK\n\nThe Math Book: Big Ideas Simply Explained\n\nDiscover more than 85 of the most important mathematical ideas, theorems, and proofs ever devised, and the great minds behind them, with this original, graphics-led book. Applying the Big Ideas Simply Explained series' trademark combination of authoritative, accessible text and bold graphics to chart the development of math through history, The Math Book explores and explains subjects ranging from ancient mathematical ideas and inventions, such as prehistoric tally bones and Sumerian multiplication tables, through the developments in mathematics during medieval and Renaissance Europe, to the more recent rise of game and group theory. Tracing math through the scientific revolution to its 21st-century use in computers, the internet, and AI, The Math Book uses an innovative graphic-led approach to make the subject accessible to everyone.\n\nThe History Book (Big Ideas Simply Explained) by DK Publishing\nAs part of DK's award-winning Big Ideas Simply Explained series, The History Book uses infographics and images to explain key ideas and The Maths Book: Big Ideas Simply Explained - DK - Google Books\nDiscover more than 85 of the most important mathematical ideas, theorems, and proofs ever devised, and the great minds behind them, with this original and The Economics Book: Big Ideas Simply Explained: DK - Amazon.ca\nThe Economics Book: Big Ideas Simply Explained Paperback – Feb 6 2018 .. on the mathematical models, this book brings back the important economics The Maths Book: Big Ideas Simply Explained by DK Publishing\nThe Maths Book book. Read reviews from world's largest community for readers. Discover more than 85 of the most important mathematical ideas, theorems, a The Literature Book (Big Ideas Simply Explained) - Harvard Book\nA global look at the greatest works of Eastern and Western literature and the themes that unite them, for students and lovers of literature and The Math Book by DK | PenguinRandomHouse.com: Books\nApplying the Big Ideas Simply Explained series' trademark combination of authoritative, accessible text and bold graphics to chart the development of math through history, The Math Book explores and explains subjects ranging from ancient mathematical ideas and inventions, such as prehistoric tally bones and Sumerian Big Ideas Learning Student Edition - Big Ideas Math\nBig Ideas MATH: A Focal Points Curriculum. Middle School Math Textbooks Written by Ron Larson and Laurie Boswell."
] | [
null,
"http://prodimage.images-bn.com/pimages/9781465480248.jpg",
null,
"https://i.imgur.com/s7YtI18.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.74174935,"math_prob":0.6075886,"size":3567,"snap":"2020-34-2020-40","text_gpt3_token_len":785,"char_repetition_ratio":0.1692394,"word_repetition_ratio":0.3147482,"special_character_ratio":0.2054948,"punctuation_ratio":0.1168,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9640943,"pos_list":[0,1,2,3,4],"im_url_duplicate_count":[null,1,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-09-20T13:52:56Z\",\"WARC-Record-ID\":\"<urn:uuid:19c81f24-04b9-4beb-83e9-9f00f2b66008>\",\"Content-Length\":\"11812\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:f5827190-d378-47d1-9c00-06e084538364>\",\"WARC-Concurrent-To\":\"<urn:uuid:9def6f89-91d9-4e90-aaab-3f7f4469f725>\",\"WARC-IP-Address\":\"212.27.63.52\",\"WARC-Target-URI\":\"http://ylamifeb.blog.free.fr/index.php?post/2020/05/29/Download-ebooks-for-ipad-2-The-Math-Book%3A-Big-Ideas-Simply-Explained\",\"WARC-Payload-Digest\":\"sha1:5X5Z62GHVUH7NUWGI5YCRKHKF63EMQVM\",\"WARC-Block-Digest\":\"sha1:7AESSO4IL5HWTTX32AN6AYMYITKIR66K\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-40/CC-MAIN-2020-40_segments_1600400198213.25_warc_CC-MAIN-20200920125718-20200920155718-00592.warc.gz\"}"} |
https://tex.stackexchange.com/questions/104453/in-math-mode-line-non-math-type | [
"# In “math-mode line” non-math type\n\nI'd like to type non-math text inside of the bracket math text lines, or know of a better way to do what I'm trying to do.\n\nIn the following, I don't literally type \\nomath. I don't know what I need to type there in order to make this work.\n\nThis is what I type (the dashes are disappearing, I don't know why):\n\n\\begin{document}\n\n$K=L$\n\n$A = B \\nomath or \\nomath A_1 = B_1$\n\n\\end{document}\n\n\nThis is what I get:\n\nK=L\n\nA=B\n\nor\n\nA_1=B_1\n\nThis is what I want:\n\nK=L\n\nA=B or A_1=B_1\n\nWhat I'd like for the or word to be in non-math text mode, with everything around it following the normal rules according to the dashes and brackets. Can anyone help me?\n\n• Welcome to TeX.sx! A tip: If you indent lines by 4 spaces, they'll be marked as a code sample. You can also highlight the code and click the \"code\" button (with \"{}\" on it). – jubobs Mar 26 '13 at 20:43\n• Thanks for editing the post so it looks nicer, and where I can find more posting tips. – rod Mar 26 '13 at 22:19\n\n## 1 Answer\n\nIf you use the amsmath package, you should be able to write something like\n\n$A = B \\text{ or } A_1 = B_1$\n\n\nYou'll have to manually add space around the or. You can do it as I did or you can do it as:\n\n$A = B \\quad \\text{or} \\quad A_1 = B_1$\n\n\nEDIT 1\n\nHere's a complete MWE:\n\n\\documentclass{article}\n\\usepackage{amsmath}\n\\pagestyle{empty}\n\\begin{document}\n\n$A = B \\text{ or } A_1 = B_1$\n\n$A = B \\quad \\text{or} \\quad A_1 = B_1$\n\n\\end{document}\n\n\nEDIT 2\n\nA comparison of \\mbox{...} vs \\text{...}\n\n$A_{\\mbox{Hi}} \\text{ vs } A_{\\text{Hi}}$\n\n\nIf you want to know more about the differences between these, you should probably post another question.\n\n• Thanks for the answer. Although I couldn't get any of your suggestions to work, you gave me the terminology I needed to find what I could get to work, which was using \"\\mbox{ or }\". – rod Mar 26 '13 at 22:03\n• Did you use \\usepackage{amsmath} in the preamble to your document? – A.Ellett Mar 26 '13 at 22:30\n• Maybe? I guess the preamble isn't the part before the \\documentclass{article}, but after. When I put \\usepackage{amsmath} before \\documentclass{article}, \\text{or} doesn't work as I desired. After, and it does. On a related note, is there any effective difference between \\mbox{or} and \\text{or}? – rod Mar 27 '13 at 4:42\n• Usually, the \\documentclass{...} declaration should come at the beginning of the document. There are exceptions to this. But if you are new to LaTeX, that might be a good rule of thumb to initially follow. Yes, there is a difference between \\mbox{or} and \\text{or}. In brief, \\text{...} is sensitive to its context and chooses the correct font size. See 2nd edit above. – A.Ellett Mar 27 '13 at 5:19"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.94750756,"math_prob":0.710834,"size":639,"snap":"2019-13-2019-22","text_gpt3_token_len":191,"char_repetition_ratio":0.12598425,"word_repetition_ratio":0.0,"special_character_ratio":0.28951487,"punctuation_ratio":0.083333336,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9884731,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-05-21T10:58:18Z\",\"WARC-Record-ID\":\"<urn:uuid:e0e4984f-e594-4495-bc0a-c086aecb7ba9>\",\"Content-Length\":\"136867\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:7d0b8fa9-4e00-4990-85bb-9d071d2e8d3f>\",\"WARC-Concurrent-To\":\"<urn:uuid:76aa10df-dc72-4ae9-97ca-d5c38fab13f9>\",\"WARC-IP-Address\":\"151.101.65.69\",\"WARC-Target-URI\":\"https://tex.stackexchange.com/questions/104453/in-math-mode-line-non-math-type\",\"WARC-Payload-Digest\":\"sha1:QZNQ63BOG5OKGSJSUKAH2GDIQFESXVSR\",\"WARC-Block-Digest\":\"sha1:RNHVFMBQDYCVTAQVD2G36Q4U2M6LI3KM\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-22/CC-MAIN-2019-22_segments_1558232256314.52_warc_CC-MAIN-20190521102417-20190521124417-00475.warc.gz\"}"} |
http://philiplaven.com/p3b.html | [
"## Variability in size of raindrops\n\nThe Mie algorithm assumes scattering from a single sphere, but a rainbow involves scattering from millions of raindrops. In practice, raindrops are not of uniform size. MiePlot simulates the effect of size dispersion by performing N calculations for sizes described by Normal or Log-Normal statistical distributions. Fig. 5 shows that even very small variations in the size of the drops (e.g. a standard deviation of 0.1%) can have a considerable effect.",
null,
"",
null,
"",
null,
"Scattering angle (degrees)",
null,
"Scattering angle (degrees) Fig. 5 Intensity v. scattering angle for red light (0.65 µm wavelength) by a water drop of nominal radius 100 µm for perpendicular polarisation"
] | [
null,
"http://philiplaven.com/Fig5a.gif",
null,
"http://philiplaven.com/Fig5b.gif",
null,
"http://philiplaven.com/Fig5c1.gif",
null,
"http://philiplaven.com/Fig5d1.gif",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.88035464,"math_prob":0.98380667,"size":588,"snap":"2019-51-2020-05","text_gpt3_token_len":125,"char_repetition_ratio":0.1130137,"word_repetition_ratio":0.045454547,"special_character_ratio":0.20238096,"punctuation_ratio":0.115384616,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9782968,"pos_list":[0,1,2,3,4,5,6,7,8],"im_url_duplicate_count":[null,3,null,3,null,3,null,3,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-01-26T05:12:04Z\",\"WARC-Record-ID\":\"<urn:uuid:e61604ab-29a4-4a88-bcc7-6e8dfb08c029>\",\"Content-Length\":\"2754\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:afe605fa-4487-4069-ad64-9008a1d396ea>\",\"WARC-Concurrent-To\":\"<urn:uuid:999377e2-eeab-4fc4-881b-a2526f60a417>\",\"WARC-IP-Address\":\"192.252.146.23\",\"WARC-Target-URI\":\"http://philiplaven.com/p3b.html\",\"WARC-Payload-Digest\":\"sha1:6FCNSUQDNV3NBHY5PWHEUJV42GY5J5I7\",\"WARC-Block-Digest\":\"sha1:LLOYBCPOGEF6UI54CLOOWKIMRIBMY7JZ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-05/CC-MAIN-2020-05_segments_1579251687725.76_warc_CC-MAIN-20200126043644-20200126073644-00367.warc.gz\"}"} |
https://worksheetzone.org/math/compound-probability-worksheet | [
"",
null,
"# Compoundprobabilityworksheets\n\nThe compound probability worksheet is one of the most basic concepts from a mathematics perspective. The probability of an event is seen as the measure of the possibility of the occurrence of that event. Compound probability is applicable when there is more than one independent event taking place. We have an example of a compound event - suppose, you need to roll a die, and toss a coin. Now if you are required to find the probability of getting 6 after rolling the die and getting heads at the same time, then that becomes a question. Our experts developed a set of compound probability worksheets that consists of many questions; from basic to advanced levels. These worksheets would help the students to understand their concepts clearly and help them in their exams, as well as, help them in their calculations. Students would also be able to calculate the probability of an event before performing it, in real life! These math worksheets should be practiced regularly to be able to grasp this challenging compound probability with ease. Let’s check these compound probability worksheets out and measure the probability you can earn a high score after finishing these worksheets!\n\nOn WorksheetZone, we have millions of free printable worksheets ready for you to use. Let's get started!\n\n10filtered results"
] | [
null,
"https://worksheetzone.org/images/logo_mobile.svg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.97081393,"math_prob":0.876528,"size":1291,"snap":"2023-40-2023-50","text_gpt3_token_len":238,"char_repetition_ratio":0.16627817,"word_repetition_ratio":0.0,"special_character_ratio":0.18357863,"punctuation_ratio":0.08547009,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.990622,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-09-28T11:11:29Z\",\"WARC-Record-ID\":\"<urn:uuid:40dc7192-c911-454d-89a2-e905f3b3ce5e>\",\"Content-Length\":\"267883\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:7b6ea9ff-a1ec-4474-b139-465ebacf47d3>\",\"WARC-Concurrent-To\":\"<urn:uuid:404e082b-504c-44b8-a920-15f301fc8d16>\",\"WARC-IP-Address\":\"104.21.79.226\",\"WARC-Target-URI\":\"https://worksheetzone.org/math/compound-probability-worksheet\",\"WARC-Payload-Digest\":\"sha1:GRUW7NO35JCA36YCAK4W4MQQPURB3U7M\",\"WARC-Block-Digest\":\"sha1:FM3ME3XM5ZHYJIYS3HJMZDDWTUW2M5LX\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-40/CC-MAIN-2023-40_segments_1695233510387.77_warc_CC-MAIN-20230928095004-20230928125004-00152.warc.gz\"}"} |
https://shapenet.org/qaforum/index.php?qa=116&qa_1=how-are-the-samples-shapenetcore-v2-transformed-the-ones-of | [
"# How are the samples of ShapeNetCore v2 transformed w.r.t. the ones of v1?\n\nHello,\n\nI would like to ask what are the transformation used to align the data samples coming from v1 and v2? As explained in the README, the v2 samples are rotated by 90 degrees around y-axis, but visualization of the corresponding samples from v1 and v2 reveals that there is also a translation and scale applied to some of the samples. Even though each sample from v2 comes with a model_normalized.json file, it is not clear how to interpret the values stored in these files, since all the \"min\", \"max\" and \"centroid\" values are too huge and represent 3D points lying way out of the 3D models of either v1 or v2. Could you please point me to where I can find the transformations applied to the samples from v2 so that it would be possible to align them with v1?\n\nThank you\n\nJan\n\nI've done some extensive research and finally find the answer:\n\n• For shapenet v1, v1_norm = (v-center) / norm(diag)\n• For shapenet v2, v2_norm = (v-centroid) / norm(diag)\n\nwhere:\n\n• 'diag' stands for the bounding box diagonal vector, calculated by 'max' - 'min' from the json.\n• 'center' stands for the bounding box center, calculated by ('max'+'min')/2. from the json.\n• and the 'centroid' stands for the mean point of all mesh's vertices, from the 'centroid' in the json.\n\nso, v1_norm = v2_norm + (centroid - center) / norm(diag)\n\nand v2_norm = v1_norm + (center - centroid) / norm(diag)\n\nAfter re-scale, the rotation matrix (left-multiply):\n\nfrom v2 to v1: np.array([[0, 0, 1], [0, 1, 0], [-1, 0, 0]])\n\nfrom v1 to v2: np.array([[0, 0, -1], [0, 1, 0], [1, 0, 0]])\n\nanswered Apr 16 by (190 points)\nedited Apr 26"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6445634,"math_prob":0.9883033,"size":758,"snap":"2021-31-2021-39","text_gpt3_token_len":258,"char_repetition_ratio":0.1392573,"word_repetition_ratio":0.015748031,"special_character_ratio":0.37598944,"punctuation_ratio":0.21118012,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9867955,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-08-02T09:23:24Z\",\"WARC-Record-ID\":\"<urn:uuid:ce7c3f71-f2f7-4fb2-bf66-69a1694eca59>\",\"Content-Length\":\"17442\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e67c258a-f54f-4c21-b217-57c220121445>\",\"WARC-Concurrent-To\":\"<urn:uuid:d482e829-f1d9-4d71-a217-470fa26cc216>\",\"WARC-IP-Address\":\"34.213.15.89\",\"WARC-Target-URI\":\"https://shapenet.org/qaforum/index.php?qa=116&qa_1=how-are-the-samples-shapenetcore-v2-transformed-the-ones-of\",\"WARC-Payload-Digest\":\"sha1:RU275O7XZ73OAWHCAC6B5YYA4F3CYAAJ\",\"WARC-Block-Digest\":\"sha1:KEU53QEG2IHYYLWVIIPXCK5OJX6STSSI\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-31/CC-MAIN-2021-31_segments_1627046154310.16_warc_CC-MAIN-20210802075003-20210802105003-00248.warc.gz\"}"} |
https://scholar.ufs.ac.za/xmlui/handle/11660/442 | [
"Recent Submissions\n\n• A structural approach to the endomorphisms of certain abelian groups \n\n(University of the Free State, 2016-09)\nEnglish: Given a set S, and any selfmap ƒ: S→S, the functional graph associated with ƒ can be described as a graph with vertex set S and directed edge set E = {(u; v) ϵ S2 : ƒ (u) = v}. A classification of all functional ...\n• Analysis of numerical approximation algorithms for nonlinear differential equations using a discrete multiple scales technique \n\n(University of the Free State, 2002-12)\nEnglish: Perturbation techniques for the solution of differential equations form an essential ingredient of the tools of mathematics as applied to physics, engineering, finance and other areas of applied mathematics. A ...\n• Contributions to the theory of near vector spaces \n\n(University of the Free State, 2007-09)\nThe main purpose of this thesis is to give an exposition of and expand the theory of near vector spaces, as first introduced by Andr´e . The notion of a vector space is well known. For this reason the material in this ...\n• Adaptive dynamics for an age-structured population model with a Shepherd recruitment function \n\n(University of the Free State, 2013-06-07)\nEnglish: In this study the evolution of the genetic composition of certain species will be replaced by the evolution of the traits that represent these genetic compositions. Depending on the nature of the trait of interest, ..."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8936928,"math_prob":0.90180695,"size":1491,"snap":"2019-43-2019-47","text_gpt3_token_len":326,"char_repetition_ratio":0.12104909,"word_repetition_ratio":0.025641026,"special_character_ratio":0.22132796,"punctuation_ratio":0.121323526,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.95169187,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-10-15T22:53:30Z\",\"WARC-Record-ID\":\"<urn:uuid:74d50253-11b0-4055-96a3-6ed35716484a>\",\"Content-Length\":\"22726\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:dffdb687-cf27-41ee-8288-0c1bc7362c4f>\",\"WARC-Concurrent-To\":\"<urn:uuid:4561379d-294b-49f1-b1c1-0d51ecac6bd8>\",\"WARC-IP-Address\":\"196.255.240.49\",\"WARC-Target-URI\":\"https://scholar.ufs.ac.za/xmlui/handle/11660/442\",\"WARC-Payload-Digest\":\"sha1:GCQ3ERHFBGI3V2HL3JQJJJ7T4I7WIBZG\",\"WARC-Block-Digest\":\"sha1:YBUS6HW2KRXUIEB4CYQ5ZD3Q73VYIMI7\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-43/CC-MAIN-2019-43_segments_1570986660323.32_warc_CC-MAIN-20191015205352-20191015232852-00144.warc.gz\"}"} |
https://lists.gnu.org/archive/html/emacs-elpa-diffs/2020-02/msg00120.html | [
"emacs-elpa-diffs\n[Top][All Lists]\n\n## [elpa] master a758e6a 051/135: Added tests for finders\n\n From: Ian Dunn Subject: [elpa] master a758e6a 051/135: Added tests for finders Date: Mon, 17 Feb 2020 10:52:51 -0500 (EST)\n\n```branch: master\ncommit a758e6a873830fa908394b78977ac0439c9c3eeb\n\n* org-edna.el (org-edna-finder/siblings): Fixed case where current headline\nis\nthe first sibling.\n(org-edna-finder/siblings-wrap): Wrap movements in save-excursion to allow\n\n* org-edna-tests.el, org-edna-tests.org: Tests for the rest of the finders.\n---\norg-edna-tests.el | 145 +++++++++++++++++++++++++++++++++++++++++++++++++----\norg-edna-tests.org | 16 ++++++\norg-edna.el | 17 ++++---\n3 files changed, 160 insertions(+), 18 deletions(-)\n\ndiff --git a/org-edna-tests.el b/org-edna-tests.el\nindex 14c0caa..46f5f49 100644\n--- a/org-edna-tests.el\n+++ b/org-edna-tests.el\n@@ -28,6 +28,27 @@\n(require 'org-edna)\n(require 'ert)\n\n+(defconst org-edna-test-dir\nbuffer-file-name))))\n+\n+(defconst org-edna-test-file\n+ (expand-file-name \"org-edna-tests.org\" org-edna-test-dir))\n+\n+;; Jan 15, 2000; chosen at random\n+(defconst org-edna-test-time\n+ (encode-time 0 0 0 15 1 2000))\n+\n+(defconst org-edna-test-sibling-one-id\n\"82a4ac3d-9565-4f94-bc84-2bbfd8d7d96c\")\n+(defconst org-edna-test-sibling-two-id\n\"72534efa-e932-460b-ae2d-f044a0074815\")\n+(defconst org-edna-test-sibling-three-id\n\"06aca55e-ce09-46df-80d7-5b52e55d6505\")\n+(defconst org-edna-test-parent-id\n\"21b8f1f5-14e8-4677-873d-69e0389fdc9e\")\n+\n+ \"Find the test heading with id ID.\"\n+ (with-current-buffer (find-file-noselect org-edna-test-file)\n+ (goto-char (org-find-entry-with-id id))\n+ (point-marker)))\n+\n(ert-deftest org-edna-parse-form-no-arguments ()\n(let* ((input-string \"test-string\")\n(parsed (org-edna-parse-form input-string)))\n@@ -102,16 +123,6 @@\n(should (not modifier1))\n(should (= pos1 (length input-string))))))\n\n-(defconst org-edna-test-dir\nbuffer-file-name))))\n-\n-(defconst org-edna-test-file\n- (expand-file-name \"org-edna-tests.org\" org-edna-test-dir))\n-\n-;; Jan 15, 2000; chosen at random\n-(defconst org-edna-test-time\n- (encode-time 0 0 0 15 1 2000))\n-\n\n;; Finders\n\n@@ -155,6 +166,118 @@\n(should (string-equal (substring-no-properties org-block-entry-blocking)\n\n+(ert-deftest org-edna-finder/file ()\n+ (let* ((targets (org-edna-finder/file org-edna-test-file)))\n+ (should (= (length targets) 1))\n+ (should (markerp (nth 0 targets)))\n+ (org-with-point-at (nth 0 targets)\n+ (should (equal (current-buffer) (find-buffer-visiting\norg-edna-test-file)))\n+ (should (equal (point) 1)))))\n+\n+(ert-deftest org-edna-finder/org-file ()\n+ (let* ((org-directory (file-name-directory org-edna-test-file))\n+ (targets (org-edna-finder/org-file (file-name-nondirectory\norg-edna-test-file))))\n+ (should (= (length targets) 1))\n+ (should (markerp (nth 0 targets)))\n+ (org-with-point-at (nth 0 targets)\n+ (should (equal (current-buffer) (find-buffer-visiting\norg-edna-test-file)))\n+ (should (equal (point) 1)))))\n+\n+(ert-deftest org-edna-finder/self ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find \"82a4ac3d-9565-4f94-bc84-2bbfd8d7d96c\" t))\n+ (targets (org-with-point-at current (org-edna-finder/self))))\n+ (should (= (length targets) 1))\n+ (should (equal current (nth 0 targets)))))\n+\n+(ert-deftest org-edna-finder/siblings ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find \"82a4ac3d-9565-4f94-bc84-2bbfd8d7d96c\" t))\n+ (siblings (mapcar\n+ (lambda (uuid) (org-id-find uuid t))\n+ '(\"72534efa-e932-460b-ae2d-f044a0074815\"\n+ \"06aca55e-ce09-46df-80d7-5b52e55d6505\")))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/siblings))))\n+ (should (= (length targets) 2))\n+ (should (equal siblings targets))))\n+\n+(ert-deftest org-edna-finder/siblings-wrap ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find \"72534efa-e932-460b-ae2d-f044a0074815\" t))\n+ (siblings (mapcar\n+ (lambda (uuid) (org-id-find uuid t))\n+ '(\"06aca55e-ce09-46df-80d7-5b52e55d6505\"\n+ \"82a4ac3d-9565-4f94-bc84-2bbfd8d7d96c\")))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/siblings-wrap))))\n+ (should (= (length targets) 2))\n+ (should (equal siblings targets))))\n+\n+(ert-deftest org-edna-finder/rest-of-siblings ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find \"72534efa-e932-460b-ae2d-f044a0074815\" t))\n+ (siblings (mapcar\n+ (lambda (uuid) (org-id-find uuid t))\n+ '(\"06aca55e-ce09-46df-80d7-5b52e55d6505\")))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/rest-of-siblings))))\n+ (should (= (length targets) 1))\n+ (should (equal siblings targets))))\n+\n+(ert-deftest org-edna-finder/next-sibling ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find \"72534efa-e932-460b-ae2d-f044a0074815\" t))\n+ (siblings (mapcar\n+ (lambda (uuid) (org-id-find uuid t))\n+ '(\"06aca55e-ce09-46df-80d7-5b52e55d6505\")))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/next-sibling))))\n+ (should (= (length targets) 1))\n+ (should (equal siblings targets))))\n+\n+(ert-deftest org-edna-finder/previous-sibling ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find \"06aca55e-ce09-46df-80d7-5b52e55d6505\" t))\n+ (siblings (mapcar\n+ (lambda (uuid) (org-id-find uuid t))\n+ '(\"72534efa-e932-460b-ae2d-f044a0074815\")))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/previous-sibling))))\n+ (should (= (length targets) 1))\n+ (should (equal siblings targets))))\n+\n+(ert-deftest org-edna-finder/first-child ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find org-edna-test-parent-id t))\n+ (first-child (list (org-id-find org-edna-test-sibling-one-id t)))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/first-child))))\n+ (should (= (length targets) 1))\n+ (should (equal first-child targets))))\n+\n+(ert-deftest org-edna-finder/children ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find org-edna-test-parent-id t))\n+ (children (mapcar\n+ (lambda (uuid) (org-id-find uuid t))\n+ `(,org-edna-test-sibling-one-id\n+ ,org-edna-test-sibling-two-id\n+ ,org-edna-test-sibling-three-id)))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/children))))\n+ (should (= (length targets) 3))\n+ (should (equal children targets))))\n+\n+(ert-deftest org-edna-finder/parent ()\n+ (let* ((org-agenda-files `(,org-edna-test-file))\n+ (current (org-id-find org-edna-test-sibling-one-id t))\n+ (parent (list (org-id-find org-edna-test-parent-id t)))\n+ (targets (org-with-point-at current\n+ (org-edna-finder/parent))))\n+ (should (= (length targets) 1))\n+ (should (equal parent targets))))\n+\n\n;; Actions\n\n@@ -196,7 +319,7 @@\n(pairs '((cp . rm) (copy . remove) (\"cp\" . \"rm\") (\"copy\" .\n\"remove\"))))\n(org-with-point-at target\n(dolist (pair pairs)\n- (message \"Pair: %s\" pair)\n+ ;; (message \"Pair: %s\" pair)\n(org-edna-action/scheduled source (car pair))\n(should (string-equal (org-entry-get nil \"SCHEDULED\")\n\"<2000-01-15 Sat 00:00>\"))\ndiff --git a/org-edna-tests.org b/org-edna-tests.org\nindex 666ec1e..f44702f 100644\n--- a/org-edna-tests.org\n+++ b/org-edna-tests.org\n@@ -44,6 +44,22 @@ SCHEDULED: <2017-01-01 Sun>\n:PROPERTIES:\n:ID: 5594d4f1-b1bb-400f-9f3d-e2f9b43e82c3\n:END:\n+:PROPERTIES:\n+:ID: 21b8f1f5-14e8-4677-873d-69e0389fdc9e\n+:END:\n+*** Sibling 1\n+:PROPERTIES:\n+:ID: 82a4ac3d-9565-4f94-bc84-2bbfd8d7d96c\n+:END:\n+*** Sibling 2\n+:PROPERTIES:\n+:ID: 72534efa-e932-460b-ae2d-f044a0074815\n+:END:\n+*** Sibling 3\n+:PROPERTIES:\n+:ID: 06aca55e-ce09-46df-80d7-5b52e55d6505\n+:END:\n* Finder Tests\n** Match\n*** TODO Blocking Test\ndiff --git a/org-edna.el b/org-edna.el\nindex da8747a..cd83eb7 100644\n--- a/org-edna.el\n+++ b/org-edna.el\n@@ -266,7 +266,8 @@ IDS are all UUIDs as understood by `org-id-find'.\"\n(markers))\n(org-goto-first-child)\n- (push (point-marker) markers)\n+ (unless (equal (point) self)\n+ (push (point-marker) markers))\n(while (org-get-next-sibling)\n(unless (equal (point) self)\n(push (point-marker) markers)))\n@@ -277,15 +278,17 @@ IDS are all UUIDs as understood by `org-id-find'.\"\n(let ((self (and (ignore-errors (org-back-to-heading t)) (point)))\n(markers))\n;; Go from this heading to the end\n- (while (org-get-next-sibling)\n- (unless (equal (point) self)\n- (push (point-marker) markers)))\n+ (save-excursion\n+ (while (org-get-next-sibling)\n+ (unless (equal (point) self)\n+ (push (point-marker) markers))))\n;; Go to the first heading\n(org-goto-first-child)\n- (while (not (equal (point) self))\n- (push (point-marker) markers)\n- (org-get-next-sibling))\n+ (save-excursion\n+ (while (not (equal (point) self))\n+ (push (point-marker) markers)\n+ (org-get-next-sibling)))\n(nreverse markers))))\n\n(defun org-edna-finder/rest-of-siblings ()\n\n```"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.61648655,"math_prob":0.4801514,"size":10998,"snap":"2020-10-2020-16","text_gpt3_token_len":3793,"char_repetition_ratio":0.20283791,"word_repetition_ratio":0.27228525,"special_character_ratio":0.40352792,"punctuation_ratio":0.104957804,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99309975,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-04-09T15:18:40Z\",\"WARC-Record-ID\":\"<urn:uuid:c0f3d416-72ba-4153-9977-c43baef7fba0>\",\"Content-Length\":\"18337\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:3a6e4c56-b543-47db-877f-d6348cdd403d>\",\"WARC-Concurrent-To\":\"<urn:uuid:0268f47b-ac90-45fa-909f-7704f5708130>\",\"WARC-IP-Address\":\"209.51.188.17\",\"WARC-Target-URI\":\"https://lists.gnu.org/archive/html/emacs-elpa-diffs/2020-02/msg00120.html\",\"WARC-Payload-Digest\":\"sha1:GF2TOSD5QVBRPE53KIGCKNP2AWK6CMWZ\",\"WARC-Block-Digest\":\"sha1:HL45C5M6YD32GO5XRDGMWCJU3P6ZPGKE\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-16/CC-MAIN-2020-16_segments_1585371858664.82_warc_CC-MAIN-20200409122719-20200409153219-00288.warc.gz\"}"} |
https://www.triangle-calculator.com/?what=sss&a=5&b=18&c=20&submit=1 | [
"# Triangle calculator SSS - result\n\nPlease enter the triangle sides:\n\n### Obtuse scalene triangle.\n\nSides: a = 5 b = 18 c = 20\n\nArea: T = 43.15659671424\nPerimeter: p = 43\nSemiperimeter: s = 21.5\n\nAngle ∠ A = α = 13.8722102735° = 13°52'20″ = 0.24221138669 rad\nAngle ∠ B = β = 59.66986476367° = 59°40'7″ = 1.04114143615 rad\nAngle ∠ C = γ = 106.4599249628° = 106°27'33″ = 1.85880644252 rad\n\nHeight: ha = 17.2622386857\nHeight: hb = 4.79551074603\nHeight: hc = 4.31655967142\n\nMedian: ma = 18.86113361139\nMedian: mb = 11.46773449412\nMedian: mc = 8.63113382508\n\nInradius: r = 2.00772542857\nCircumradius: R = 10.42772949906\n\nVertex coordinates: A[20; 0] B[0; 0] C[2.525; 4.31655967142]\nCentroid: CG[7.50883333333; 1.43985322381]\nCoordinates of the circumscribed circle: U[10; -2.95444002473]\nCoordinates of the inscribed circle: I[3.5; 2.00772542857]\n\nExterior(or external, outer) angles of the triangle:\n∠ A' = α' = 166.1287897265° = 166°7'40″ = 0.24221138669 rad\n∠ B' = β' = 120.3311352363° = 120°19'53″ = 1.04114143615 rad\n∠ C' = γ' = 73.54107503717° = 73°32'27″ = 1.85880644252 rad\n\n# How did we calculate this triangle?\n\n### 1. The triangle circumference is the sum of the lengths of its three sides",
null,
"### 2. Semiperimeter of the triangle",
null,
"### 3. The triangle area using Heron's formula",
null,
"### 4. Calculate the heights of the triangle from its area.",
null,
"### 5. Calculation of the inner angles of the triangle using a Law of Cosines",
null,
"### 6. Inradius",
null,
"### 7. Circumradius",
null,
"### 8. Calculation of medians",
null,
"#### Look also our friend's collection of math examples and problems:\n\nSee more informations about triangles or more information about solving triangles."
] | [
null,
"https://www.triangle-calculator.com/tex/59e/59e4a031e8298.svg",
null,
"https://www.triangle-calculator.com/tex/46c/46c771070fa35.svg",
null,
"https://www.triangle-calculator.com/tex/0d8/0d8e185e1f060.svg",
null,
"https://www.triangle-calculator.com/tex/576/576b03a67144f.svg",
null,
"https://www.triangle-calculator.com/tex/c44/c442736cdf070.svg",
null,
"https://www.triangle-calculator.com/tex/a7a/a7a514a16c1e7.svg",
null,
"https://www.triangle-calculator.com/tex/aa4/aa42e8639b77a.svg",
null,
"https://www.triangle-calculator.com/tex/dd0/dd030695ef4c9.svg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6602824,"math_prob":0.99737954,"size":1451,"snap":"2019-35-2019-39","text_gpt3_token_len":562,"char_repetition_ratio":0.14029026,"word_repetition_ratio":0.0,"special_character_ratio":0.52997935,"punctuation_ratio":0.21843003,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9996169,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16],"im_url_duplicate_count":[null,2,null,null,null,2,null,2,null,2,null,2,null,2,null,2,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-08-20T09:47:10Z\",\"WARC-Record-ID\":\"<urn:uuid:f2451ca5-c029-4e6f-9f9a-58ed0b5696e8>\",\"Content-Length\":\"19098\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:86705b32-00ac-4dfc-b525-9ad013776005>\",\"WARC-Concurrent-To\":\"<urn:uuid:8004f78d-4d5a-460d-8564-b97f69086575>\",\"WARC-IP-Address\":\"104.28.13.22\",\"WARC-Target-URI\":\"https://www.triangle-calculator.com/?what=sss&a=5&b=18&c=20&submit=1\",\"WARC-Payload-Digest\":\"sha1:WMULW7PNJUE7P4SWAYXE575SZQT73AIZ\",\"WARC-Block-Digest\":\"sha1:ZZ4RX6SBU2Q6BBXU7ZFINIPR63BYEV6A\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-35/CC-MAIN-2019-35_segments_1566027315321.52_warc_CC-MAIN-20190820092326-20190820114326-00476.warc.gz\"}"} |
http://weyond.com/events/74/176/ | [
"## TechTalks from event: FOCS 2011\n\nWe will be uploading the videos for FOCS 2011 during the week of Nov 28th 2011. If you find any discrepancy, please let us know by clicking on report error link on talk page. If you did not permit the video to be published and by mistake we have published your talk, please notify us immediately at support AT weyond.com\n\n## 5B\n\n• The Complexity of Quantum States - a combinatorial approach Authors: Dorit Aharonov, Itai Arad, Zeph Landau, Umesh Vazirani\nThe classical description of quantum states is in general exponential in the number of qubits. Can we get polynomial descriptions for more restricted sets of states such as ground states of interesting subclasses of local Hamiltonians? This is the basic problem in the study of the complexity of ground states, and requires an understanding of multi-particle entanglement and quantum correlations in such states. We propose a combinatorial approach to this question, based on a reformulation of the detectability lemma introduced by us in the context of quantum gap amplification \\cite{ref:Aha09b}. We give an alternative proof of the detectability lemma which is not only simple and intuitive, but also removes a key restriction in the original statement, making it more suitable for this new context. We then provide a one page proof of Hastings' proof that the correlations in the ground states of Gapped Hamiltonians decay exponentially with the distance, demonstrating the simplicity of the combinatorial approach for those problems. As our main application, we provide a combinatorial proof of Hastings' seminal 1D area law \\cite{ref:Has07} for the special case of frustration free systems. Area laws provide a fundamental ingredient in the study of the complexity of ground states, since they offer a way to bound in a quantitative way the entanglement in such states. An intricate combinatorial analysis allows us to significantly improve the bounds achieved in Hastings proofs, and derive an exponentially better scaling in terms of the inverse spectral gap and the dimensionality of the particles. This holds out hope that the new approach might be a promising route towards resolving the 2D case and higher dimensions, which is one of the most important open questions in Hamiltonian complexity.\n• On the complexity of Commuting Local Hamiltonians, and tight conditions for Topological Order in such systems Authors: Dorit Aharonov and Lior Eldar\nThe local Hamiltonian problem plays the equivalent role of SAT in quantum complexity theory. Understanding the complexity of the intermediate case in which the constraints are quantum but all local terms in the Hamiltonian commute, is of importance for conceptual, physical and computational complexity reasons. Bravyi and Vyalyi showed in 2003 \\cite{BV}, using a clever application of the representation theory of C*-algebras, that if the terms in the Hamiltonian are all two-local, the problem is in NP, and the entanglement in the ground states is local. The general case remained open since then. In this paper we extend this result beyond the two-local case, to the case of three-qubit interactions. We then extend our results even further, and show that NP verification is possible for three-wise interaction between qutrits as well, as long as the interaction graph is planar and also \"nearly Euclidean\" in some well-defined sense. The proofs imply that in all such systems, the entanglement in the ground states is local. These extensions imply an intriguing sharp transition phenomenon in commuting Hamiltonian systems: the ground spaces of 3-local \"physical\" systems based on qubits and qutrits are diagonalizable by a basis whose entanglement is highly local, while more involved interactions (the particle dimensionality or the locality of the interaction is larger) can already exhibit topological order; In particular, for those parameters, there exist Hamiltonians all of whose groundstates have entanglement which spreads over scales proportional to the size of the system, such as Kitaev's Toric Code system. This has a direct implication to the developing theory of Topological Order, since it shows that one cannot improve on the parameters to construct topological order systems based on commuting Hamiltonians. This is of particular interest in light of the recent proofs by Bravyi, Hastings and Michalakis\n• Quantum query complexity of state conversion Authors: Troy Lee and Rajat Mittal and Ben W. Reichardt and Robert Spalek and Mario Szegedy\nState-conversion generalizes query complexity to the problem of converting between two input-dependent quantum states by making queries to the input. We characterize the complexity of this problem by introducing a natural information-theoretic norm that extends the Schur product operator norm. The complexity of converting between two systems of states is given by the distance between them, as measured by this norm. In the special case of function evaluation, the norm is closely related to the general adversary bound, a semi-definite program that lower-bounds the number of input queries needed by a quantum algorithm to evaluate a function. We thus obtain that the general adversary bound characterizes the quantum query complexity of any function whatsoever. This generalizes and simplifies the proof of the same result in the case of boolean input and output. Also in the case of function evaluation, we show that our norm satisfies a remarkable composition property, implying that the quantum query complexity of the composition of two functions is at most the product of the query complexities of the functions, up to a constant. Finally, our result implies that discrete and continuous-time query models are equivalent in the bounded-error setting, even for the general state-conversion problem.\n• Optimal bounds for quantum bit commitment Authors: André Chailloux and Iordanis Kerenidis\nBit commitment is a fundamental cryptographic primitive with numerous applications. Quantum information allows for bit commitment schemes in the information theoretic setting where no dishonest party can perfectly cheat. The previously best-known quantum protocol by Ambainis achieved a cheating probability of at most 3/4. On the other hand, Kitaev showed that no quantum protocol can have cheating probability less than 1/sqrt{2}(his lower bound on coin flipping can be easily extended to bit commitment). Closing this gap has since been an important open question. In this paper, we provide the optimal bound for quantum bit commitment. First, we show a lower bound of approximately 0.739, improving Kitaev's lower bound. For this, we present some generic cheating strategies for Alice and Bob and conclude by proving a new relation between the trace distance and fidelity of two quantum states. Second, we present an optimal quantum bit commitment protocol which has cheating probability arbitrarily close to \\$0.739\\$. More precisely, we show how to use any weak coin flipping protocol with cheating probability 1/2 + eps in order to achieve a quantum bit commitment protocol with cheating probability 0.739 + O(eps). We then use the optimal quantum weak coin flipping protocol described by Mochon. Last, in order to stress the fact that our protocol uses quantum effects beyond the weak coin flip, we show that any classical bit commitment protocol with access to perfect weak (or strong) coin flipping has cheating probability at least 3/4."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.91798633,"math_prob":0.93156636,"size":7214,"snap":"2019-43-2019-47","text_gpt3_token_len":1413,"char_repetition_ratio":0.13051318,"word_repetition_ratio":0.017905103,"special_character_ratio":0.1833934,"punctuation_ratio":0.07648953,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9524827,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-11-20T04:06:17Z\",\"WARC-Record-ID\":\"<urn:uuid:a5a0be70-e9e9-4e5c-9836-082a737a20f9>\",\"Content-Length\":\"38817\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:1400fd22-960b-4049-8735-f940dca70914>\",\"WARC-Concurrent-To\":\"<urn:uuid:c7491fec-1faa-45b8-a3d0-49de2ef63ea4>\",\"WARC-IP-Address\":\"173.230.131.71\",\"WARC-Target-URI\":\"http://weyond.com/events/74/176/\",\"WARC-Payload-Digest\":\"sha1:CIEZXK7SOVGVEV542FN2MYBYQIEXOJY6\",\"WARC-Block-Digest\":\"sha1:JV52E6UN4HZO3DS5DO6SXOBLN4OEFWRW\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-47/CC-MAIN-2019-47_segments_1573496670448.67_warc_CC-MAIN-20191120033221-20191120061221-00060.warc.gz\"}"} |
http://www.CMStatistics.org/RegistrationsV2/CFE2021/viewSubmission.php?in=1510&token=8322q6so0610qq6pq19949s6sp49n113 | [
"CMStatistics 2021: Start Registration",
null,
"View Submission - CFE\nA1510\nTitle: Test assets and weak factors Authors: Stefano Giglio - Yale and NBER (United States) [presenting]\nAbstract: Estimation and testing of factor models in asset pricing require choosing a set of test assets. The choice of test assets determines how well different factor risk premia can be identified: if only a few assets are exposed to a factor, that factor is weak, which makes standard estimation and inference incorrect. In other words, the strength of a factor is not an inherent property of the factor: it is a property of the cross-section used in the analysis. We propose a novel way to select assets from a universe of test assets and estimate the risk premium of a factor of interest, as well as the entire stochastic discount factor, that explicitly accounts for weak factors and test assets with highly correlated risk exposures. We refer to our methodology as supervised principal component analysis (SPCA), because it iterates an asset selection step and a principal-component estimation step. We provide the asymptotic properties of our estimator, and compare its limiting behavior with that of alternative estimators proposed in the recent literature, which rely on PCA, Ridge, Lasso, and Partial Least Squares (PLS). We find that the SPCA is superior in the presence of weak factors, both in theory and in finite samples. We illustrate the use of SPCA by applying it to estimate the risk premia of several tradable and nontradable factors, to evaluate asset manager's performance, and to de-noise asset pricing factors."
] | [
null,
"http://www.CMStatistics.org/RegistrationsV2/CFE2021/menu_files/HeaderCFE2021.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9273252,"math_prob":0.7271931,"size":1546,"snap":"2022-05-2022-21","text_gpt3_token_len":312,"char_repetition_ratio":0.14202334,"word_repetition_ratio":0.0,"special_character_ratio":0.19016817,"punctuation_ratio":0.09642857,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9595526,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-05-24T12:39:10Z\",\"WARC-Record-ID\":\"<urn:uuid:38902b4b-b835-4c7e-8d6b-bb4f59a4fb29>\",\"Content-Length\":\"5855\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:90fb6ae3-2f55-4745-8e23-6b15fce22455>\",\"WARC-Concurrent-To\":\"<urn:uuid:17dda206-d61d-4948-b8a1-4d4a40288c17>\",\"WARC-IP-Address\":\"208.113.212.214\",\"WARC-Target-URI\":\"http://www.CMStatistics.org/RegistrationsV2/CFE2021/viewSubmission.php?in=1510&token=8322q6so0610qq6pq19949s6sp49n113\",\"WARC-Payload-Digest\":\"sha1:25E6RC23R3PJRB7I56HGFEQMKYQ3JLDD\",\"WARC-Block-Digest\":\"sha1:WKGIGNSPBCQMBP7PU32FVVJLJZ3NTOT5\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-21/CC-MAIN-2022-21_segments_1652662572800.59_warc_CC-MAIN-20220524110236-20220524140236-00144.warc.gz\"}"} |
http://ehs.svvsd.org/updates/get-your-own-calculator-asap | [
"# Get Your Own Calculator ASAP\n\nDid you know that 65% of the math questions on the SAT allow a calculator? CollegeBoard recommends students bring a calculator with which they are familiar to the SAT to avoid confusion and wasted time trying to figure out a new calculator. This tip will increase SAT scores and reduce any test day stress. A list of approved calculators can be found on the CollegeBoard website, and in general most scientific and graphing calculators are allowed on the SAT, PSAT and AP exams. iPads, cell phones, and smart watches cannot be used on the SAT, PSAT or AP exams.\n\nStudents should have their own calculator to use in math class and to complete their math assignments. This should be the same calculator they plan to use for the PSAT, SAT, and/or AP exams. By using the same calculator daily, students will become familiar with the calculator’s features and will learn how the calculator can help them become more efficient and effective math problem solvers.\n\nFor Algebra 1 and Geometry, the Erie High Math Department recommends a scientific calculator (such as the Texas Instruments 30XS or Casio FX155ES). Make sure the scientific calculator has the trigonometric functions (sin, cos, and tan), a square root button, and an exponent button. For students in Algebra 2, Pre-Calculus, Trigonometry, Finite Math, Statistics, and Calculus, a graphing calculator (such as the TI-84) is recommended. Students learn how to use the graphic calculator and all of its graphing features while in thee courses. Graphing calculators are an investment. Please keep in mind that students can use graphing calculators for their entire high school career and any post-secondary pathway. If your student is in AP Calculus or AP Statistics, a portion of the AP exam is graphing calculator required. The teachers for these courses will work with students to ensure they learn the necessary calculator skills for the AP exams. iPads and cell phones cannot be used for calculators on math assessments at Erie High School. If you have any questions about the appropriate calculator for your student, please talk to any Erie High math teacher or check out the course syllabus. The calculator recommendations are listed under the materials section of the syllabus."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.91067576,"math_prob":0.94343376,"size":2437,"snap":"2019-51-2020-05","text_gpt3_token_len":525,"char_repetition_ratio":0.1594739,"word_repetition_ratio":0.0,"special_character_ratio":0.21091506,"punctuation_ratio":0.09750567,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9550112,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-12-07T02:48:15Z\",\"WARC-Record-ID\":\"<urn:uuid:c20b91c8-2d19-4d37-82bd-55d7d371768d>\",\"Content-Length\":\"34552\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:15d7dd4d-2121-4e55-b88c-0120f2ef979d>\",\"WARC-Concurrent-To\":\"<urn:uuid:1b876f37-477d-4373-8103-6a888f7dd685>\",\"WARC-IP-Address\":\"34.232.162.81\",\"WARC-Target-URI\":\"http://ehs.svvsd.org/updates/get-your-own-calculator-asap\",\"WARC-Payload-Digest\":\"sha1:XOFTM7MBEKIYDPF4QHRQVTSVA2RH3LUL\",\"WARC-Block-Digest\":\"sha1:57Z6K3R7YBS7JIO7H6MZHAD2ILOXN6BE\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-51/CC-MAIN-2019-51_segments_1575540491871.35_warc_CC-MAIN-20191207005439-20191207033439-00299.warc.gz\"}"} |
https://zbmath.org/?q=an:1138.37019 | [
"# zbMATH — the first resource for mathematics\n\nLarge derivatives, backward contraction and invariant densities for interval maps. (English) Zbl 1138.37019\nSummary: We study the dynamics of a smooth multimodal interval map $$f$$ with nonflat critical points and all periodic points hyperbolic repelling. Assuming that $$|Df^{n}(f(c))|\\rightarrow \\infty$$ as $$n\\rightarrow \\infty$$ holds for all critical points $$c$$, we show that $$f$$ satisfies the so called backward contracting property with an arbitrarily large constant, and that $$f$$ has an invariant probability $$\\mu$$ which is absolutely continuous with respect to Lebesgue measure and the density of $$\\mu$$ belongs to $$L^{p}$$ for all $$p<\\ell_{\\max}/(\\ell_{\\max}-1)$$, where $$\\ell_{\\max}$$ denotes the maximal critical order of $$f$$. In the appendix, we prove that various growth conditions on the derivatives along the critical orbits imply stronger backward contraction.\n\n##### MSC:\n 37E05 Dynamical systems involving maps of the interval 37C40 Smooth ergodic theory, invariant measures for smooth dynamical systems\nFull Text:\n##### References:\n Bruin, H.: The existence of absolutely continuous invariant measures is not a topological invariant for unimodal maps. Ergodic Theory Dyn. Syst. 18(3), 555–565 (1998) · Zbl 0928.37004 Bruin, H.: Invariant measures of interval maps. Ph.D. Thesis, University of Delft (1994) · Zbl 0812.58052 Bruin, H., Keller, G., Nowicki, T., van Strien, S.: Wild attractors exist. Ann. Math. 143(1), 97–130 (1996) · Zbl 0848.58016 Bruin, H., Shen, W., van Strien, S.: Invariant measure exists without a growth condition. Commun. Math. Phys. 241, 287–306 (2003) · Zbl 1098.37034 Bruin, H., van Strien, S.: Existence of invariant measures for multimodal interval maps. In: Global Analysis of Dynamical Systems, pp. 433–447. Inst. Phys., Bristol (2001) · Zbl 1198.37066 Collet, P., Eckmann, J.-P.: Positive Liapunov exponents and absolutely continuity for maps of the interval. Ergodic Theory Dyn. Syst. 3(1), 13–46 (1983) · Zbl 0532.28014 Graczyk, J., Sands, D.: Manuscript in preparation Misiurewicz, M.: Absolutely continuous measures for certain maps of an interval. Publ. Math., Inst. Hautes ’Etud. Sci. 53, 17–51 (1981) · Zbl 0477.58020 de Melo, W., van Strien, S.: One-Dimensional Dynamics. Springer, Berlin (1993) · Zbl 0791.58003 Nowicki, T., van Strien, S.: Hyperbolicity properties of C 2 multi-modal Collet–Eckmann maps without Schwarzian derivative assumptions. Trans. Am. Math. Soc. 321(2), 793–810 (1990) · Zbl 0731.58021 Nowicki, T., van Strien, S.: Invariant measures exist under a summability condition for unimodal maps. Invent. Math. 105, 123–136 (1991) · Zbl 0736.58030 Rivera-Letelier, J.: A connecting lemma for rational maps satisfying a no growth condition. Ergodic Theory Dyn. Syst. 27(2), 595–636 (2007) · Zbl 1110.37037 van Strien, S., Vargas, E.: Real Bounds, ergodicity and negative Schwarzian for multimodal maps. J. Am. Math. Soc. 17(4), 749–782 (2004) · Zbl 1073.37043\nThis reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6490722,"math_prob":0.97730607,"size":3738,"snap":"2021-31-2021-39","text_gpt3_token_len":1096,"char_repetition_ratio":0.11515801,"word_repetition_ratio":0.009276438,"special_character_ratio":0.33146068,"punctuation_ratio":0.24935733,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98339427,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-08-06T03:05:59Z\",\"WARC-Record-ID\":\"<urn:uuid:fff74562-e2bf-4538-8fb8-cccbd831a68b>\",\"Content-Length\":\"51604\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:870db2b8-9895-4966-8601-de36d9eb5a4a>\",\"WARC-Concurrent-To\":\"<urn:uuid:3d614636-d8b1-4286-ad3b-2bdd71c133af>\",\"WARC-IP-Address\":\"141.66.194.2\",\"WARC-Target-URI\":\"https://zbmath.org/?q=an:1138.37019\",\"WARC-Payload-Digest\":\"sha1:DF4N2R337SQMELBPT4ECJZYO4JZHH62F\",\"WARC-Block-Digest\":\"sha1:HLVWSTQL3B3JN2UYDSRX6T2VLRLZQLSJ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-31/CC-MAIN-2021-31_segments_1627046152112.54_warc_CC-MAIN-20210806020121-20210806050121-00486.warc.gz\"}"} |
http://www.talkstats.com/threads/help-with-ill-formed-emails-to-r-help.24975/ | [
"Help with ill formed emails to R-help\n\ntrinker\n\nggplot2orBust\nWhen I write emails to R help list they always wind up messed up and make me look dumb. I've tried using plain text format and rich text in hotmail and the outcome is the same, el sucko. (Here's the LINK to the threaded archive)\n\nHere's an example:\n\nWhat it looks like\nCode:\nMy solution:\nSP <- split(df, df[, 1:2])\nminner <- function(x, col = 'numMiss') { x[which.min(unlist(x[,col])), , drop=FALSE]}\nNEW <- do.call('rbind', lapply(SP, minner))SP2 <- split(NEW, NEW[, 'id'])do.call('rbind', lapply(SP2, function(x) minner(x, 'A')))\n\nCheers,Tyler\nWhat it should look like\nCode:\nMy solution:\nSP <- split(df, df[, 1:2])\nminner <- function(x, col = 'numMiss') {\nx[which.min(unlist(x[,col])), , drop=FALSE]\n}\nNEW <- do.call('rbind', lapply(SP, minner))\nSP2 <- split(NEW, NEW[, 'id'])\ndo.call('rbind', lapply(SP2, function(x) minner(x, 'A')))\n\nCheers,\nTyler\nAny ideas on this non stats question?"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6433534,"math_prob":0.9433248,"size":923,"snap":"2022-05-2022-21","text_gpt3_token_len":283,"char_repetition_ratio":0.10446137,"word_repetition_ratio":0.23703703,"special_character_ratio":0.32719395,"punctuation_ratio":0.2200957,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9849632,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-01-20T01:24:35Z\",\"WARC-Record-ID\":\"<urn:uuid:f2b344b6-1417-4492-986d-23191406a2f1>\",\"Content-Length\":\"31800\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:1ad89a0d-5f6d-4cdf-ab29-d6ee9414f6d9>\",\"WARC-Concurrent-To\":\"<urn:uuid:b455c8d9-d43b-4dba-bbfd-5f68b1dee299>\",\"WARC-IP-Address\":\"199.167.200.62\",\"WARC-Target-URI\":\"http://www.talkstats.com/threads/help-with-ill-formed-emails-to-r-help.24975/\",\"WARC-Payload-Digest\":\"sha1:YYOKAFB3OCN43POHFK75OMIMTQYGS25V\",\"WARC-Block-Digest\":\"sha1:X72RBI7Q5HBWQYVD5GNE6XWKKS37LOOF\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-05/CC-MAIN-2022-05_segments_1642320301670.75_warc_CC-MAIN-20220120005715-20220120035715-00652.warc.gz\"}"} |
https://ncatlab.org/nlab/show/Hahn-Banach+theorem | [
"# Contents\n\n## Idea\n\nThe Hahn–Banach theorem explains why the concept of locally convex spaces is of interest in the analysis of topological vector spaces: It ensures that such a space will have enough continuous linear functionals such that the topological dual space is interesting.\n\n## Statement\n\n###### Theorem\n\nLet $V$ be a vector space over a local field $K$ (usually $\\mathbb{R}$ or $\\mathbb{C}$), equipped with a seminorm $p: V \\to [0, \\infty)$. Let $W \\subseteq V$ be a subspace, and $f: W \\to K$ a linear functional such that ${|f(x)|} \\leq p(x)$ for all $x \\in W$, then there exists an extension of $f$ to a linear functional $g: V \\to K$ such that ${|g(x)|} \\leq p(x)$ for all $x \\in V$.\n\n## Foundational issues\n\nThe full Hahn–Banach theorem may be seen as a weak form of the axiom of choice; this is the perspective taken in, for example, HAF. It fails in dream mathematics and is generally not accepted in constructive mathematics. (Does it actually imply excluded middle?)\n\nThe Hahn-Banach theorem can be proven in set theory with the axiom of choice, or more weakly in set theory assuming the ultrafilter theorem, itself a weak form of choice. (To be continued…)\n\nHowever, the Hahn–Banach theorem for separable spaces is much weaker. It may be proved constructively using only dependent choice. There is also a version of the theorem for locales (or so I heard)."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.93302053,"math_prob":0.9970629,"size":1250,"snap":"2021-04-2021-17","text_gpt3_token_len":278,"char_repetition_ratio":0.1187801,"word_repetition_ratio":0.028037382,"special_character_ratio":0.2136,"punctuation_ratio":0.10204082,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99950445,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-01-27T17:51:43Z\",\"WARC-Record-ID\":\"<urn:uuid:766eeaaf-7722-4d91-8087-8119257a583a>\",\"Content-Length\":\"20264\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:ba562e21-7159-4f17-995f-d5021ff5ba29>\",\"WARC-Concurrent-To\":\"<urn:uuid:74f43949-e605-4d5e-97a3-ab387ccf0994>\",\"WARC-IP-Address\":\"172.67.137.123\",\"WARC-Target-URI\":\"https://ncatlab.org/nlab/show/Hahn-Banach+theorem\",\"WARC-Payload-Digest\":\"sha1:IW44TDKMDPQD46C7DATUNS3RXYKIUDXY\",\"WARC-Block-Digest\":\"sha1:N6TATDFIZPR4RZ4SRTIKAA6XNHKYA4FB\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-04/CC-MAIN-2021-04_segments_1610704828358.86_warc_CC-MAIN-20210127152334-20210127182334-00400.warc.gz\"}"} |
https://answers.opencv.org/question/96474/projectpoints-functionality-question/ | [
"# projectPoints functionality question\n\nI'm doing something similar to the tutorial here: http://docs.opencv.org/3.1.0/d7/d53/t... regarding pose estimation. Essentially, I'm creating an axis in the model coordinate system and using ProjectPoints, along with my rvecs, tvecs, and cameraMatrix, to project the axis onto the image plane.\n\nIn my case, I'm working in the world coordinate space, and I have an rvec and tvec telling me the pose of an object. I'm creating an axis using world coordinate points (which assumes the object wasn't rotated or translated at all), and then using projectPoints() to draw the axes the object in the image plane.\n\nI was wondering if it is possible to eliminate the projection, and get the world coordinates of those axes once they've been rotated and translated. To test, I've done the rotation and translation on the axis points manually, and then use projectPoints to project them onto the image plane (passing identity matrix and zero matrix for rotation, translation respectively), but the results seem way off. How can I eliminate the projection step to just get the world coordinates of the axes, once they've been rotation and translated? Thanks!\n\nedit retag close merge delete\n\nSort by » oldest newest most voted\n\nI am not sure to understand you correctly when you said:\n\n(which assumes the object wasn't rotated or translated at all)\n\nto eliminate the projection, and get the world coordinates of those axes once they've been rotated and translated\n\nAnyway, even if it does not answer your question I will try to add some useful information.\n\nWhat you have is the camera pose or the transformation matrix that allows to transform a coordinate in the world frame to the corresponding coordinate in the camera frame:",
null,
"",
null,
"The perspective projection projects the 3D coordinates in the camera frame to the image plane according to the pinhole camera model:",
null,
"The full operation when you want to draw for example the world frame origin in the image plane should be:",
null,
"Now if you know the geometric transformation between two frames w1 and w2:",
null,
"To draw the coordinate of a point in frame w2 onto the image plane, you have to first compute its coordinate in the camera frame:",
null,
"This figure should illustrate the situation:",
null,
"I hope that what I have written is mostly correct.\n\nmore\n\nSo if I understand you correctly, I just need to rotate and translate the axis using rvecs and tvecs, and that should be what I need.\n\nThe problem is, I use solvePnP to get the rotation and translation for a face. And I draw an axis on the face and use projectPoints to draw it on the image plane. I want to find the world coordinates of the axis after its rotated. What I did was find the rotation matrix using Rodrigues, and do rotation_matrix*axis_point + tvec. And then used projectPoints to project the result of that onto the image plane (passing identity matrix and zero matrix for rotation, tvec respectively). But the result of that was different than what I got from just using projectPoints normally. Why is that?\n\nIt should be the same result:\n\n cv::Mat K = (cv::Mat_<double>(3,3) <<\n700, 0, 320,\n0, 700, 240,\n0, 0, 1);\n\ndouble theta = 24.0 * M_PI / 180.0;\ncv::Mat rvec = (cv::Mat_<double>(3,1) <<\n0.4, 0.2, 0.8944) * theta;\ncv::Mat R;\ncv::Rodrigues(rvec, R);\n\ncv::Mat tvec = (cv::Mat_<double>(3,1) <<\n0.5, 0.38, 1.4);\n\ncv::Mat mat_point_x = (cv::Mat_<double>(3,1) <<\n1, 0, 0);\n\nstd::vector<cv::Point3f> object_points;\ncv::Point3f object_point_x(1, 0, 0);\nobject_points.push_back(object_point_x);\nstd::vector<cv::Point2f> image_points;\n\n\nCode:\n\ncv::projectPoints(object_points, rvec, tvec, K, cv::noArray(), image_points);\n\nstd::cout << \"image_point_x=\" << image_points.front() << std::endl;\n\ncv::Mat cam_image_point_x = R * mat_point_x + tvec;\ncv::Point3f cam_image_point_x2(\ncam_image_point_x.at<double>(0), cam_image_point_x.at<double>(1), cam_image_point_x.at<double>(2));\nobject_points.clear();\nobject_points.push_back(cam_image_point_x2);\n\nimage_points.clear();\ncv::projectPoints(object_points, cv::Mat::eye(3, 3, CV_64F), cv::Mat::zeros(3,1,CV_64F), K, cv::noArray(), image_points);\nstd::cout << \"image_point_x_2=\" << image_points.front() << std::endl;\n\n\nYou can use cv::aruco::drawAxis which displays your axis with the given rvec and tvec. Remember to add #include \"opencv2/aruco.hpp\"\n\nmore\n\nThere is now drawFrameAxes() in calib3d module (OpenCV >= 4.0.1 or OpenCV >= 3.4.5). No more required to build the contrib modules if not needed.\n\nOfficial site\n\nGitHub\n\nWiki\n\nDocumentation"
] | [
null,
"https://answers.opencv.org/upfiles/14659845494290495.png",
null,
"https://answers.opencv.org/upfiles/14659846287703544.png",
null,
"https://answers.opencv.org/upfiles/14659843713508204.png",
null,
"https://answers.opencv.org/upfiles/14659847552536622.png",
null,
"https://answers.opencv.org/upfiles/14659852757767335.png",
null,
"https://answers.opencv.org/upfiles/1465995370354687.png",
null,
"https://answers.opencv.org/upfiles/14659954837141011.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8828895,"math_prob":0.94808155,"size":1183,"snap":"2021-31-2021-39","text_gpt3_token_len":249,"char_repetition_ratio":0.14843087,"word_repetition_ratio":0.010928961,"special_character_ratio":0.20540997,"punctuation_ratio":0.13656388,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99009,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14],"im_url_duplicate_count":[null,7,null,7,null,7,null,7,null,7,null,7,null,7,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-07-24T12:18:50Z\",\"WARC-Record-ID\":\"<urn:uuid:1c48a9b4-6019-4fcd-8e0d-75d348e8111a>\",\"Content-Length\":\"70258\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:3ab38cb8-0bce-4be3-bed1-2933a6b94f64>\",\"WARC-Concurrent-To\":\"<urn:uuid:05a8d4dc-f598-45e6-bba2-110479701b31>\",\"WARC-IP-Address\":\"5.9.49.245\",\"WARC-Target-URI\":\"https://answers.opencv.org/question/96474/projectpoints-functionality-question/\",\"WARC-Payload-Digest\":\"sha1:655VXGQDZJRQMZUE6AKZKHR57MX2M6QN\",\"WARC-Block-Digest\":\"sha1:7J7B6KO3CRX3UEEXD7AHK6QHDFMWRJ4V\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-31/CC-MAIN-2021-31_segments_1627046150264.90_warc_CC-MAIN-20210724094631-20210724124631-00197.warc.gz\"}"} |
https://softmath.com/math-book-answers/perfect-square-trinomial/math-formulas-sheet.html | [
"",
null,
"## What our customers say...\n\nThousands of users are using our software to conquer their algebra homework. Here are some of their experiences:\n\nMy daughters math teacher recommended a program called Algebrator to help her with her algebra homework. I wish this program was around when I was in college!\nMark Hansen, IL\n\nThe program is a lifesaver, thanks so much!\nMax Duncan, OH\n\nI appreciate that it is basicIt has helped me tremendously\nOscar Peterman, NJ\n\nEvery time I tried to do my algebra homework it took hours for me to finish it. But now with the Algebrator I learn and complete my homework faster.\nKeith Erich Johnston, KS\n\nYEAAAAHHHHH... IT WORKS GREAT!\nPatricia Blackwell, NJ\n\n## Search phrases used on 2014-06-04:\n\nStudents struggling with all kinds of algebra problems find out that our software is a life-saver. Here are the search phrases that today's searchers used to find our site. Can you find yours among them?\n\n• solve by substitution method calculator\n• application of algebra\n• dividing fractions number line\n• changing mixed numbers to decimals\n• area activities KS2\n• decimal into a mixed number tool\n• how to type factor equations online\n• Online Math TAKS Assignments\n• parabolas simplified\n• find the least common denominator for these two rational expression sovler\n• solving algebra equations using software\n• solving trignometric equations in matlab\n• brain teaser with answer in Trigonometry\n• fractions least to greatest online games\n• solving linear systems using ti 83\n• solving simultaneous equations calculator\n• manually program a basic quadratic formula on a ti 83 plus\n• how to multiply decimal integers\n• free Solving By Substitution Algebra 1 Problem solver\n• Jacobs' Elementary Algebra sample\n• pre algebra combining like terms worksheets free\n• Math riddles printables\n• boolean expression calculator online\n• kumon free worksheets\n• +pdf +worksheets scientific method primary grades\n• free simplify an exponential expression\n• applications of parabolas\n• glencoe algebra 1 workbook awnsers\n• convert second order differential equation to first order\n• graphing calculator multiplying integers\n• free math worksheets symmetry\n• LaPlace using TI-89\n• factoring with coefficient greater than one worksheet and printable\n• fifth grade algebra one variable equation work sheet\n• grade 8 math quiz free\n• free 9th grade algebra worksheets\n• how to use absolute value on a ti-89\n• prentice hall solving absolute value functions video\n• complex simultaneous equation calculator\n• \"algebra 2\" \"Subtracting with unlike\"\n• third grade word problems worksheet free\n• hardest multi step math problem\n• multiple step adding and subtracting integers worksheets\n• logs with base ti-83\n• glencoe physics workbook\n• maths revision exercises for binomial expressions 13 years\n• 8th grade practice theoretical probability 10-4\n• my algebra source\n• how to store data on ti 89\n• online factorise\n• blank study hall sheet forms\n• linear equations powerpoint\n• how to solve square root problems in an equations\n• calculator algebraic equations\n• math work sheet on how to differentiate between customary unit and metric unit\n• sats practise papes\n• pythagorean theorem printable worksheets\n• free gr 6 algebra math worksheets\n• free 9th grade work online\n• T1-85 texas\n• boolean algebra solver\n• \"Trigonometry for dummies online\"\n• find interscetion of two lines graphing calc\n• fun short math poems for algebra\n• ordered pairs worksheets\n• answers for prentice hall mathematics california algebra 1\n• percent math problem solver\n• calculas\n• free texas t1-83 guide\n• permutation and combination \"Math Problems\"\n• Algebra Quizzes with the answer key\n• how to find scale factor\n• cubed algebra\n• find all zeros of equation"
] | [
null,
"https://softmath.com/r-solver/images/tutor.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.853078,"math_prob":0.9396802,"size":4354,"snap":"2023-14-2023-23","text_gpt3_token_len":959,"char_repetition_ratio":0.14022988,"word_repetition_ratio":0.0,"special_character_ratio":0.20509876,"punctuation_ratio":0.036809817,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99873453,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-03-26T08:55:21Z\",\"WARC-Record-ID\":\"<urn:uuid:5dd34ae7-b394-4055-8591-41644d23bed8>\",\"Content-Length\":\"35727\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:1bb5de83-b179-49a6-ba1e-0a05d31af655>\",\"WARC-Concurrent-To\":\"<urn:uuid:7980e2c3-97e7-4b70-bb93-692a3b04ed4b>\",\"WARC-IP-Address\":\"52.43.142.96\",\"WARC-Target-URI\":\"https://softmath.com/math-book-answers/perfect-square-trinomial/math-formulas-sheet.html\",\"WARC-Payload-Digest\":\"sha1:URGATBIYOERLTOORPU4PLDRIHNLQ4RVS\",\"WARC-Block-Digest\":\"sha1:5I4ARIQRR2XACK2FM2UEQLQ62MRL5VWC\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-14/CC-MAIN-2023-14_segments_1679296945440.67_warc_CC-MAIN-20230326075911-20230326105911-00046.warc.gz\"}"} |
https://blogs.accu.org/category/actual-time/ | [
"## Actual implementation times are often round numbers\n\nTo what extent do developers consciously influence the time taken to actually complete a task?\n\nIf the time estimated to complete a task is rather generous, a developer has the opportunity to follow Parkinson’s law (i.e., “work expands so as to fill the time available for its completion”), or if the time is slightly less than appears to be required, they might work harder to finish within the estimated time (like some marathon runners have a target time)?\n\nThe use of round numbers are a prominent pattern seen in task estimation times.\n\nIf round numbers appeared more often in the actual task completion time than would be expected by chance, it would suggest that developers are sometimes working to a target time. The following plot shows the number of tasks taking a given amount of actual time to complete, for project 615 in the CESAW dataset (similar patterns are present in the actual times of other projects; code+data):",
null,
"The red lines are a fitted bi-exponential distribution to the ‘spike’ (i.e., round numbers, circled in grey) and non-spike points (spikes automatically selected, see code for details), green and purple lines are the two components of the non-spike fit.\n\nTasks are not always started and completed in one continuous work session, work may be spread over multiple work sessions; the CESAW data includes the start/end time of every work session associated with each task (85% of tasks involve more than one work session, for project 615). The following plots are based on work sessions, rather than tasks, for tasks worked on over two (left) and three (right) sessions; colored lines denote session ordering within a task (code+data):",
null,
"Shorter sessions dominate for the last session of task implementation, and spikes in the counts indicate the use of round numbers in all session positions (e.g., 180 minutes, which may be half a day).\n\nPerhaps round number work session times are a consequence of developers using round number wall-clock times to start and end work sessions. The plot below shows (left) the number of work sessions starting at a given number of minutes past the hour, and (right) the number of work sessions ending at a given number of minutes past the hour; both for project 615 (code+data):",
null,
"The arrow (green) shows the direction of the mean, and the almost invisible interior line shows that the length of the mean is almost zero. The five-minute points have slightly more session starts/ends than the surrounding minute values, but are more like bumps than spikes. The start of the hour, and 30-minutes, have prominent spikes, which might be caused by the start/end of the working day, and start/end of the lunch break.\n\nFive-minutes is a convenient small rounding interval to either expand implementation time, or to target as a completion time. The following plot shows, for each of the 47 individuals working on project 615, the number of actual session times and the number exactly divisible by five. The green line shows the case where every actual is divisible by five, the purple line where 20% are divisible by five (expected for unbiased timing), the dashed purple lines show one standard deviation, the blue/green line is a fitted regression model (",
null,
") (code+data):",
null,
"It appears that on average, five-minute session times occur twice as often as expected by chance; two individuals round all their actual session times (ok, it’s not that unlikely for the person with just two sessions).\n\nDoes it matter that some developers have a preference for using round numbers when recording time worked?\n\nThe use of round numbers in the recording of actual work sessions will inflate the total actual time for most tasks (because most tasks involve more than one session, and assuming that most rounding is not caused by developers striving to meet a target). The amount of error introduced is probably a lot less than the time variability caused by other implementation factors (I have yet to do the calculation).\n\nI see the use of round numbers as a means of unpicking developer work habits.\n\nGiven the difficulty of getting developers to record anything, requiring them to record to minute-level accuracy appears at best optimistic. Would you work for a manager that required this level of effort detail (I know there is existing practice in other kinds of jobs)?\n\n## Actual implementation times are often round numbers\n\nTo what extent do developers consciously influence the time taken to actually complete a task?\n\nIf the time estimated to complete a task is rather generous, a developer has the opportunity to follow Parkinson’s law (i.e., “work expands so as to fill the time available for its completion”), or if the time is slightly less than appears to be required, they might work harder to finish within the estimated time (like some marathon runners have a target time)?\n\nThe use of round numbers are a prominent pattern seen in task estimation times.\n\nIf round numbers appeared more often in the actual task completion time than would be expected by chance, it would suggest that developers are sometimes working to a target time. The following plot shows the number of tasks taking a given amount of actual time to complete, for project 615 in the CESAW dataset (similar patterns are present in the actual times of other projects; code+data):",
null,
"The red lines are a fitted bi-exponential distribution to the ‘spike’ (i.e., round numbers, circled in grey) and non-spike points (spikes automatically selected, see code for details), green and purple lines are the two components of the non-spike fit.\n\nTasks are not always started and completed in one continuous work session, work may be spread over multiple work sessions; the CESAW data includes the start/end time of every work session associated with each task (85% of tasks involve more than one work session, for project 615). The following plots are based on work sessions, rather than tasks, for tasks worked on over two (left) and three (right) sessions; colored lines denote session ordering within a task (code+data):",
null,
"Shorter sessions dominate for the last session of task implementation, and spikes in the counts indicate the use of round numbers in all session positions (e.g., 180 minutes, which may be half a day).\n\nPerhaps round number work session times are a consequence of developers using round number wall-clock times to start and end work sessions. The plot below shows (left) the number of work sessions starting at a given number of minutes past the hour, and (right) the number of work sessions ending at a given number of minutes past the hour; both for project 615 (code+data):",
null,
"The arrow (green) shows the direction of the mean, and the almost invisible interior line shows that the length of the mean is almost zero. The five-minute points have slightly more session starts/ends than the surrounding minute values, but are more like bumps than spikes. The start of the hour, and 30-minutes, have prominent spikes, which might be caused by the start/end of the working day, and start/end of the lunch break.\n\nFive-minutes is a convenient small rounding interval to either expand implementation time, or to target as a completion time. The following plot shows, for each of the 47 individuals working on project 615, the number of actual session times and the number exactly divisible by five. The green line shows the case where every actual is divisible by five, the purple line where 20% are divisible by five (expected for unbiased timing), the dashed purple lines show one standard deviation, the blue/green line is a fitted regression model (",
null,
") (code+data):",
null,
"It appears that on average, five-minute session times occur twice as often as expected by chance; two individuals round all their actual session times (ok, it’s not that unlikely for the person with just two sessions).\n\nDoes it matter that some developers have a preference for using round numbers when recording time worked?\n\nThe use of round numbers in the recording of actual work sessions will inflate the total actual time for most tasks (because most tasks involve more than one session, and assuming that most rounding is not caused by developers striving to meet a target). The amount of error introduced is probably a lot less than the time variability caused by other implementation factors (I have yet to do the calculation).\n\nI see the use of round numbers as a means of unpicking developer work habits.\n\nGiven the difficulty of getting developers to record anything, requiring them to record to minute-level accuracy appears at best optimistic. Would you work for a manager that required this level of effort detail (I know there is existing practice in other kinds of jobs)?"
] | [
null,
"http://www.coding-guidelines.com/images/p615-task-act.png",
null,
"http://www.coding-guidelines.com/images/p615-sessions_2-3.png",
null,
"http://www.coding-guidelines.com/images/p615-rose_start-end.png",
null,
"http://shape-of-code.coding-guidelines.com/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_994.5_6321bb396a66d1944042209021660c38.png",
null,
"http://www.coding-guidelines.com/images/p615-act-sess_div5.png",
null,
"http://www.coding-guidelines.com/images/p615-task-act.png",
null,
"http://www.coding-guidelines.com/images/p615-sessions_2-3.png",
null,
"http://www.coding-guidelines.com/images/p615-rose_start-end.png",
null,
"http://shape-of-code.coding-guidelines.com/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_994.5_6321bb396a66d1944042209021660c38.png",
null,
"http://www.coding-guidelines.com/images/p615-act-sess_div5.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.92912346,"math_prob":0.94955856,"size":4339,"snap":"2021-31-2021-39","text_gpt3_token_len":869,"char_repetition_ratio":0.1407151,"word_repetition_ratio":0.025,"special_character_ratio":0.20350312,"punctuation_ratio":0.08466258,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.96938384,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-09-16T22:51:37Z\",\"WARC-Record-ID\":\"<urn:uuid:836d76f4-0ae3-4a86-b77c-078e94fdc2ee>\",\"Content-Length\":\"170803\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:da4caac7-085f-4c77-847d-637d7fe7c121>\",\"WARC-Concurrent-To\":\"<urn:uuid:f2689942-a9e8-439c-82de-f84d7ead8fd1>\",\"WARC-IP-Address\":\"46.43.8.89\",\"WARC-Target-URI\":\"https://blogs.accu.org/category/actual-time/\",\"WARC-Payload-Digest\":\"sha1:W6434Q5TFUBTAHBKQLC6RWALOQ7ONTAM\",\"WARC-Block-Digest\":\"sha1:WN3OVILVXQLKVR2N7BI4G2RAF6XFD6H5\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-39/CC-MAIN-2021-39_segments_1631780053759.24_warc_CC-MAIN-20210916204111-20210916234111-00220.warc.gz\"}"} |
https://www.osapublishing.org/jlt/abstract.cfm?&uri=jlt-27-10-1315 | [
"## Abstract\n\nIn this paper, the performance of a two-port single-mode fiber–silicon wire waveguide coupler module which utilizes an identical spot-size converter (SSC) at the input and output ports is reported. Each of the silicon (Si)-based SSCs comprised cascaded horizontal linear and vertical nonlinear up-tapers measured 300 and 200 $\\mu$m in length, respectively, in a common silicon-on-insulator (SOI) substrate. The structural parameters of the tapers were designed for compactness and relaxed tolerance to fabrication errors. The total length of the two-port coupler module was 1000 $\\mu$m plus the variable length of the wire waveguide connecting the two SSCs. The mode-field diameter (MFD) of the Si-wire waveguide, 0.32$\\,\\times\\,$0.46 $\\mu$m$^{2}$, was transformed to the diameter of 2.8$\\,\\times\\,$8.0 $\\mu$m$^{2}$ at the wavelength of 1.55 $\\mu$m (corresponding to an area expansion of about 150 times) and vice versa by the SSCs with a net transmission loss of 4.1 dB/port. The field-mismatch loss between the SSC and the single-mode fiber with the MFD of 5.2 $\\mu$m was 2.1 dB/port.\n\n### References\n\nYou do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.867285,"math_prob":0.93982244,"size":1732,"snap":"2021-31-2021-39","text_gpt3_token_len":422,"char_repetition_ratio":0.09837963,"word_repetition_ratio":0.27480915,"special_character_ratio":0.22979215,"punctuation_ratio":0.093655586,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.95903164,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-09-17T12:47:22Z\",\"WARC-Record-ID\":\"<urn:uuid:418e8648-eec4-4df1-ad30-a6a008e0a86b>\",\"Content-Length\":\"83007\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:4c42cc27-76b3-477b-9abd-adb7d0ff88de>\",\"WARC-Concurrent-To\":\"<urn:uuid:eaa14e93-4d3f-4246-8ecc-c7f1d466f1ef>\",\"WARC-IP-Address\":\"65.202.222.60\",\"WARC-Target-URI\":\"https://www.osapublishing.org/jlt/abstract.cfm?&uri=jlt-27-10-1315\",\"WARC-Payload-Digest\":\"sha1:S2YARDUFUMSGL37F6UE4AZ6OPNXCPUNU\",\"WARC-Block-Digest\":\"sha1:T3EWA2ILXQB2LTEULD55YVBEPYRXVRCW\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-39/CC-MAIN-2021-39_segments_1631780055645.75_warc_CC-MAIN-20210917120628-20210917150628-00010.warc.gz\"}"} |
http://forum.math.toronto.edu/index.php?PHPSESSID=kac663dnd4f2osj4gjn0othah6&action=profile;area=showposts;sa=messages;u=863 | [
"###",
null,
"Show Posts\n\nThis section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.\n\n### Messages - Ge Shi\n\nPages: \n1\n##### Quiz-2 / Re: Q2 TUT 5201\n« on: October 06, 2018, 01:51:09 AM »\n(1)\nApply ratio test:\n|[Z^n+1 / (n+1)!] / [Z^n / n!]|=|Z| / n+1\nLimit |Z| / n+1= 0 < 1 as n approaches infinity\nthus it converges for all z\n\n(2)\nApply ratio test:\n|[(-1)^n+1*Z^2(n+1) / (2n+1)!]/ [(-1)^n*Z^2n / (2n)!]| = |Z^2| / 2n+1\nLimit |Z^2| / 2n+1 = 0 < 1 as n approaches infinity.\nthus it converges for all z\n\n2\n##### Quiz-1 / Re: Q1: TUT 0203\n« on: September 28, 2018, 05:11:53 PM »\nSince the circle through 0, 2+2i, 2-2i,\nIt means that the circle through (0,0), (2,2) and (2,-2)\nthus, the equation of this circle in complex form is |z-2|=2\n\n3\n##### Quiz-6 / Re: Q6--T0401\n« on: March 17, 2018, 01:50:00 PM »\n(a)\n\n4\n##### Quiz-6 / Re: Q6--T0201\n« on: March 17, 2018, 12:11:47 AM »\n(a)\nIn the attachement\n\n(b)\nWhen t approaches to infinity, the solution is approaches to zero\n\nSince $\\lambda_1=-3$ , $\\lambda_2=-1$\nEigenvalues are real but unequal and have the same sign, x=0 is a node and asymptotically stable.\n\n5\n##### Quiz-6 / Re: Q6--T0401\n« on: March 16, 2018, 11:48:09 PM »\n(a)\nhttps://imgur.com/a/W9njS\n\n(b)\n\nWhen t approaches to infinity:\nif C2 is not equal to zero ,the solution is unbounded.\nif C2 is equal to zero, the solution approaches to zero.\n\nSince $\\lambda_1=-1$ , $\\lambda_2=2$\nEigenvalues are real but unequal and have the opposite signs, x=0 is a saddle point and unstable.\nI've attached the graph.\n\n6\n##### MAT244--Misc / Re: week 7 quiz?\n« on: February 11, 2018, 04:07:34 PM »\nNo, since we have our midterm, we don't have a quiz next week but we still have the tutorial.\nYou can check the website\nhttp://www.math.toronto.edu/courses/mat244h1/20181/homeassignments.html\n\n7\n##### Web Bonus Problems / Re: Web bonus problem--Week 3\n« on: January 22, 2018, 11:49:46 PM »",
null,
""
] | [
null,
"http://forum.math.toronto.edu/Themes/default/images/icons/profile_sm.gif",
null,
"http://i1347.photobucket.com/albums/p709/shigevertas/WechatIMG2_zpsi8ssxkgk.jpeg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.7078948,"math_prob":0.9620881,"size":749,"snap":"2023-14-2023-23","text_gpt3_token_len":350,"char_repetition_ratio":0.09127517,"word_repetition_ratio":0.8652482,"special_character_ratio":0.5126836,"punctuation_ratio":0.10989011,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9852704,"pos_list":[0,1,2,3,4],"im_url_duplicate_count":[null,null,null,3,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-06-09T20:56:42Z\",\"WARC-Record-ID\":\"<urn:uuid:d8b022ed-fd3e-4e68-8ea7-b99005dac689>\",\"Content-Length\":\"21389\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:edba71cf-d840-45d1-be66-39ffda169cf8>\",\"WARC-Concurrent-To\":\"<urn:uuid:69e72ebe-a2ae-420b-ad11-db8b599ea11b>\",\"WARC-IP-Address\":\"142.150.233.214\",\"WARC-Target-URI\":\"http://forum.math.toronto.edu/index.php?PHPSESSID=kac663dnd4f2osj4gjn0othah6&action=profile;area=showposts;sa=messages;u=863\",\"WARC-Payload-Digest\":\"sha1:ZPQASBUCETVIFLW3WTDY7XIAOQOMDP2R\",\"WARC-Block-Digest\":\"sha1:MRSV346SOSMKS2MCLWWAJID4EHAOTPTJ\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-23/CC-MAIN-2023-23_segments_1685224656833.99_warc_CC-MAIN-20230609201549-20230609231549-00079.warc.gz\"}"} |
https://cs.stackexchange.com/questions/10056/leftist-heap-determining-time-complexity | [
"# Leftist heap - determining time complexity\n\nThe time complexity of merge (union) operation is said to be $O(\\lg (n_1 + n_2))$, where $n_1$ and $n_2$ are the numbers of elements in the merged heaps, respectively. I do not understand this - the algorithm has to go through all the elements of both rightmost paths of the original heaps - lengths of these paths are bound by $O(\\lg n_1)$ and $O(\\lg n_2)$. That makes $O(\\lg n_1 + \\lg n_2)$ in total, which is $O(\\lg (n_1 n_2))$. Where am I making a mistake in my assumptions?\n\nArbitrary delete operation - the complexity should be $O(\\lg n)$, where $n$ is the size of the heap. But after the deletion, the algorithm has to go through all the nodes from the parent of the deleted node to the root and correct the Leftist property, and the lenght of this path is bound by $O(n)$. Again, where am I wrong?\n\n• Really arbitrary delete? I only have seen delete-min, which merges the trees at the two children of the root. – Hendrik Jan Feb 24 '13 at 17:31\n• Yes, arbitrary. I have seen multiple sources saying that arbitrary delete can be done in O(lg n) time provided you use an additional parent pointer for each node. – kenor Feb 24 '13 at 17:39\n• $\\log(x+y) \\le \\log(xy) \\le \\log((x+y)^2) = 2\\log(x+y)$ (assuming both $x$ and $y$ are positive) – JeffE Feb 26 '13 at 5:58\n\nFor the time complexity of merging, JeffE already pointed out in the comments that $O(\\log(n_1n_2)) \\in O(\\log(n_1+n_2))$.\n• Thus, the number of updated nodes is bound by the length of a right flank in a leftist tree, which in turn is bound by $O(\\log n)$."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.94632745,"math_prob":0.9988202,"size":804,"snap":"2020-10-2020-16","text_gpt3_token_len":224,"char_repetition_ratio":0.1325,"word_repetition_ratio":0.055172414,"special_character_ratio":0.29104477,"punctuation_ratio":0.084848486,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9997938,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-03-30T23:55:31Z\",\"WARC-Record-ID\":\"<urn:uuid:20ecfd17-fdbb-4351-8fd6-989036332d13>\",\"Content-Length\":\"144226\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:33e02270-225a-49b1-aa16-566185bc3b67>\",\"WARC-Concurrent-To\":\"<urn:uuid:ad71c7eb-09a6-4341-8a27-55e5b303fcd0>\",\"WARC-IP-Address\":\"151.101.1.69\",\"WARC-Target-URI\":\"https://cs.stackexchange.com/questions/10056/leftist-heap-determining-time-complexity\",\"WARC-Payload-Digest\":\"sha1:YJXOB3257OY2VUM2DLAG4RY6IRRYX7WW\",\"WARC-Block-Digest\":\"sha1:LE4NR6D3VVGZFDNWF5SV3YFFMQKBUWCX\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-16/CC-MAIN-2020-16_segments_1585370497309.31_warc_CC-MAIN-20200330212722-20200331002722-00200.warc.gz\"}"} |
https://www.speedsolving.com/threads/accomplishment-thread.1688/page-2735 | [
"# Accomplishment Thread\n\n#### TheCoolMinxer\n\n##### Member\nWHHHHYYYYY? Y ME STILL NO sub6? pb by .02, LL was F R U R' U' F', no AUF. Can't reconstruct for some reason, but the beginning\n\n1. 6.058 R2 B U2 L2 F2 U2 L2 B2 D2 F U' F2 L' B U' F' U R B2 D'\n\nz2\nL D' R' U' F D'\nU L' U L\nU' R' U2 R U2 L U L'\n...\n\nmaybe some one else can find the rest\n\n#### Cale S\n\n##### Member\n1. 6.058 R2 B U2 L2 F2 U2 L2 B2 D2 F U' F2 L' B U' F' U R B2 D'\n\nz2\nL D' R' U' F D'\nU L' U L\nU' R' U2 R U2 L U L'\n...\n\nmaybe some one else can find the rest\nz2\nL D' R' U' F D'\nU L' U L\nU' R' U2 R U2 L U L'\nU R U' R2 U' R\ny' U' R U2 R2 U' R2 U' R'\nF R U R' U' F'",
null,
"#### TheCoolMinxer\n\n##### Member\nz2\nL D' R' U' F D'\nU L' U L\nU' R' U2 R U2 L U L'\nU R U' R2 U' R\ny' U' R U2 R2 U' R2 U' R'\nF R U R' U' F'",
null,
"Thanks a lot Cale",
null,
"More PBs:\n9.18 ao12\n9.75 ao50\n9.92 ao100 (failed a bit the end)\n\n#### Rubiks560\n\n##### Nub\nAfter MONTHS of frustration and wanting to quit speefsolving, I finally made a bit of a comeback.\n\nHoped on skype with MD cubers and picked up an AoLong v2.\n\n7.90 AO5\n8.27 AO12\n8.67 AO50\n8.81 AO100\n\n2-7 relay\n\n7:44.34\n\npb by 25s\n\n#### TraciAG\n\n##### Member\n13.08 single, first ever sub-20 ao20 at 17.89! Gans 356 rocks.\n\n#### imvelox\n\n##### Member\n29.346 35puzzle PB single wat\n\n#### TDM\n\n##### Member\n1. (36.70) B U L' F U' D2 L2 B R L2 U' R2 F2 L2 B2 U' R2 B2 D' B2\n2. (1:28.00) L U2 B2 L' B2 D2 F2 L2 F2 L' B2 F' R B' U R B' R D2 R2\n3. 46.38 F' R2 D2 F L2 R2 D2 F' L2 R2 B' U B U2 B' D R' F2 D2 R B'\n4. 41.88 D2 B2 D2 F' R2 U2 B' U' L2 R U2 L' U R F U2\n5. 43.91 L D L2 U R2 D' L2 B2 D' U' L2 U2 F D B L D' R2 B F2\n= 44.06\n3x3 sim\n\n29.346 35puzzle PB single wat",
null,
"E: 28.04 U F2 R2 B2 U' R2 B2 D' L2 U' R' B U2 L' F2 L' D' F L2\n\nE: 29.600 35 puzzle, PB is .03 faster\n\nLast edited:\n\n#### AA13\n\n##### Member\nAfter 3 months..... I FINALLY HIT SUB 20!!\n\n#### TDM\n\n##### Member\n8-puzzle, first solve of session:\n0.195, 5 moves, 25.641 TPS\n1 2 3/5 7 6/4 0 8\nDRUL2\n\n32nd solve of session:\n0.214, 6, 28.037\n1 2 3/7 0 6/5 4 8\nURDLUL\n\n#### Torch\n\n##### Member\n7.93 D L2 F2 L2 R2 D B2 U2 L2 R2 U' R U2 B' U2 B2 L2 R' D2\n\nx y2 D' L D\nU L U2 L' U y' L' U' L\nR' U2 R U' y' R' U R\nU' L' U2 L U L' U' L\nU' L U' L' U L U' L' U r' U L U'\n\n7.93/39=4.92 TPS\n\nYay, I have an LL skip as PB again!\n\n#### Michael Womack\n\n##### Member\nPB done with my Moyu Pyra\nAverage of 5: 8.49\n1. 8.07 B R L B U L' U' B' l r' b\n2. 9.77 U B U' R' U L B' U B' l' r' u\n3. 7.64 U B' R' B U' L' B' R l r u'\n4. (13.85) U L' R L' R' U' L' R b'\n5. (7.38) L U B' R' L' R' L R l r u\n\n#### Rubiks560\n\n##### Nub\n.16 off of PB 5.76\n\nF2 U' L U' R' L F' L U2 R' F2 D2 R2 U2 R2 B2 U2 D' L2\n\nx2 D R' D2 F B' R' D // cross\nU L' U L U2 L' U L // F2L 1\ny R' U' R // F2L 2\nU2 R U R' // F2L 3\nL' U' L U L' U' L U2 / F2L 4\nl' U2 L U L' U l // OLL\nU2 // PLL\n\n#### Hssandwich\n\n##### Member\nSquare-1 PB: (18.59) (4,0) / (0,3) / (-1,5) / (4,-5) / (2,-4) / (-2,0) / (-3,0) / (0,-3) / (-5,-3) / (0,-2) /\n\nAdj-adj CP with an EP skip.\n\nAO5 PB: Average: 25.08\nBest: 20.82\nWorst: 33.29\nMean: 25.87\nStandard Deviation: 4.11\n\n1: (33.29) (4,0) / (0,3) / (3,0) / (5,-4) / (-5,-2) / (-3,0) / (-1,-3) / (3,0) / (1,0) / (6,-1) / (3,-2) /\n2: 25.66 (1,0) / (-3,0) / (2,-4) / (-3,0) / (6,0) / (-3,0) / (-2,0) / (-3,0) / (0,-3) / (-1,0) / (2,-2) / (6,-1) / (4,0) / (4,0)\n3: 25.66 (0,2) / (-5,1) / (-4,-4) / (-3,0) / (-5,-2) / (0,-3) / (0,-1) / (-3,0) / (3,0) / (2,0) / (4,0) / (2,-3) / (0,-2) /\n4: 23.91 (0,2) / (-2,-5) / (-1,-4) / (-3,0) / (0,-3) / (6,-2) / (6,-3) / (0,-5) / (0,-4) / (-3,0)\n5: (20.82) (1,0) / (-3,3) / (0,3) / (0,-3) / (5,-4) / (-2,-2) / (2,0) / (6,-3) / (3,0) / (-3,0) / (-1,0) / (0,-5) /\n\nOnly 1 parity",
null,
"Also AO50: 31.69\nAO100: 32.48\n\nSub 30 is getting close!\n\n#### IRNjuggle28\n\n##### Member\n.16 off of PB 5.76\n\nF2 U' L U' R' L F' L U2 R' F2 D2 R2 U2 R2 B2 U2 D' L2\n\nx2 D R' D2 F B' R' D // cross\nU L' U L U2 L' U L // F2L 1\ny R' U' R // F2L 2\nU2 R U R' // F2L 3\nL' U' L U L' U' L U2 / F2L 4\nl' U2 L U L' U l // OLL\nU2 // PLL\nDid you really have that 5.60 6 years ago when you joined this forum? Wow. I'm surprised it's lasted that long!\n\n#### Rubiks560\n\n##### Nub\nDid you really have that 5.60 6 years ago when you joined this forum? Wow. I'm surprised it's lasted that long!\nHaha. Nope! it's just 100% pure coincidence! Some people have said maybe if I change my username, my PB would change. I've had 5.60 since 2013.\n\n#### Carbon\n\n##### Member\nFINALLY SUB 3 6x6 SINGLE\n\n2:54.48 with 2:20 lol redux stackmatted.\n\nSimilar threads"
] | [
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null,
"data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.83455026,"math_prob":0.83302975,"size":1540,"snap":"2021-04-2021-17","text_gpt3_token_len":601,"char_repetition_ratio":0.1171875,"word_repetition_ratio":0.18618618,"special_character_ratio":0.38181818,"punctuation_ratio":0.08539945,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9717532,"pos_list":[0,1,2,3,4,5,6,7,8,9,10],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-04-12T03:39:05Z\",\"WARC-Record-ID\":\"<urn:uuid:73faacc9-dcaf-4952-9d4d-552332d41ceb>\",\"Content-Length\":\"138663\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e98bc6b1-12e6-4173-9454-28d2451d2434>\",\"WARC-Concurrent-To\":\"<urn:uuid:4db02b19-ef58-456a-9ea5-93e4e63e4719>\",\"WARC-IP-Address\":\"104.21.25.109\",\"WARC-Target-URI\":\"https://www.speedsolving.com/threads/accomplishment-thread.1688/page-2735\",\"WARC-Payload-Digest\":\"sha1:R3OJC7CI46RRGD4VNVSFADJG7DD2OBHW\",\"WARC-Block-Digest\":\"sha1:7VYHH4BGQ2TLILNVSDM2MSJWZOVKDTRC\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-17/CC-MAIN-2021-17_segments_1618038066568.16_warc_CC-MAIN-20210412023359-20210412053359-00185.warc.gz\"}"} |
https://www.roseindia.net/answers/viewqa/Java-Beginners/18985-Count-number-of-occurences-and-print-names-alphabetically-in-Java.html | [
"# Count number of occurences and print names alphabetically in Java\n\nI have this code:\n\npublic class Names { public static void main(String[] args) { String[] s = {\"bob\", \"tom\", \"jim\", \"tom\", \"tom\", \"tim\"}; printCount(s); }\n\npublic static void printCount(String[] sa) { //code } }\n\nNeed to write the code for the printCount() method for the code to count the number of occurences of each word and print in alphabetical order to produce this output:\n\n{bob=1, jim=1, tim=1, tom=3}",
null,
"May 16, 2011 at 1:11 PM\n\n```import java.util.*;\n\npublic class CountWordOccurrence {\npublic static void main(String[] args){\n\nString[] st = {\"bob\", \"tom\", \"jim\", \"tom\", \"tom\", \"tim\"};\nHashMap<String, Integer> map = new HashMap<String, Integer>();\nString str=\"\";\nfor(int i=0;i<st.length;i++){\nstr+=st[i]+\" \";\n}\nstr = str.toLowerCase();\nint count = -1;\nfor (int i = 0; i < str.length(); i++) {\nif ((!Character.isLetter(str.charAt(i))) || (i + 1 == str.length())) {\nif (i - count > 1) {\nif (Character.isLetter(str.charAt(i)))\ni++;\nString word = str.substring(count + 1, i);\nif (map.containsKey(word)) {\nmap.put(word, map.get(word) + 1);\n}\nelse {\nmap.put(word, 1);\n}\n}\ncount = i;\n}\n}\nArrayList<Integer> list = new ArrayList<Integer>();\nCollections.sort(list, Collections.reverseOrder());\nint last = -1;\nfor (Integer i : list) {\nif (last == i)\ncontinue;\nlast = i;\nfor (String s : map.keySet()) {\nif (map.get(s) == i)\nSystem.out.println(s + \":\" + i);\n}\n}\n}\n}\n```\n\nCount number of occurences and print names alphabetically in Java\nCount number of occurences and print names alphabetically in Java I have this code: public class Names { public static void main(String[] args... for the printCount() method for the code to count the number of occurences of each\nSorting Country names alphabetically\nSorting Country names alphabetically Hello, I have a list of country names in an array. I need a jsp code which will sort me the country names in an alphaberical order. It would be more useful when I get the coding using\nCount number of \"*\"\nCount number of \"*\" I have this code to count the number of * from...:\"); String text = bf.readLine(); int count = 0; for (int i = 0; i...); if (c=='*' ) { count\nCount number of characters in a column.\nCount number of characters in a column. I just need you suggestions. Am from Biology Back ground. I just need to find out number of characters... to count characters in 1st, 2nd, 3rd columns seperatly and also print flase if i\njava program to insert data into a file and count the number of words from the file???????\njava program to insert data into a file and count the number of words from the file??????? java program to insert data into a file and count the number of words from the file\nprint square of any number\nprint square of any number using c++ language, write aprogram to print the square of any number entered by the user\nwrite a java program to print marklist of n students. input Register number, name and marks of three subjects.\nwrite a java program to print marklist of \"n \" students. input Register number, name and marks of three subjects. write a java program to print marklist of \"n \" students. input Register number, name and marks of three subjects\nJava count vowels\nJava count vowels In this section you will learn how to count the number... and then you will get the number of vowels count. Description of code : In this code.... to console. Example : A Code to count the number of vowel in a string\nprint the sum of even number from 1 to 100\nprint the sum of even number from 1 to 100 how to print the sum of even number from 1 to 100 using for loops? Thanks\nJava Word Count - Word Count Example in Java\nJava Word Count - Word Count Example in Java ... to count the number of lines, number of words and number of characters... some strings and program will count the number of characters and number of words\nprint selected checkbox names in array without form tag\nprint selected checkbox names in array without form tag Hi everyone ... I have problem in my program. I have hashmap i.e. collection , my... seleced checked checkbox names, when i click on button but without using FORM tag\nPrime Number program in Java\nPrime Number program in Java will print the prime numbers between 1 to any given number. Prime Number is a number that is not divisible by any number other... automatically prints Prime Number starting from 1 to 50. Example of Prime Number\nProgram to count the number of unique words in a file using HashMap\nProgram to count the number of unique words in a file using HashMap import java.io.File; import java.io.FileNotFoundException; import java.util....()); System.out.println(\"The number of unique words: \"+uniqueValues.size\nHibernate Count\nIn this section you will learn different way to count number of records in a table\nCount the character in java\nCount the character in java Write a java program to count.... Count characters by implementing thread import java.util.*; class CountCharacters { public static void count(final String str){ Runnable\nHow to print this in java?\nHow to print pattern in Java? How to print a particular pattern in Java...; How to print this in java\nRetrieve a list of words from a website and show a word count plus a specified number of most frequently occurring words\n. print: the total number of words processed, the number of unique words, the N... int N = 25; //the number of word/frequency pairs to print //word pattern...; Integer count; // number of occurrences WordPair(String word\nCounting specific word occurences in a file\nCounting specific word occurences in a file Hello I have a log file from the proxy which consists all the browsing history with date,time,url,ip... name and need to count how many times those sites(url's) are being visited\nAlphabetically sorting order\nAlphabetically sorting order Write a java program that takes a list of words from the command line and prints out the arguments in an alphabetically sorted order Hi Friend, Try the following code: import\nhow to find [count the number of integers whose value is less than the average value of the integers]\nhow to find [count the number of integers whose value is less than the average... amount to the screen integers from an operator at a terminal, and count the number... program is to display the average integer value and the count of integers less\nAsk java count Good morning, I have a case where there are tables... | Java 1 | 10 | | b002 | beginner java | 5 | | b003 | advanced java book | 26 | | b004 | MySQL 1\nHow to format number in Java?\nHow to format number in Java? Hi, What is the best way to format a number in Java? How to format number in Java? Thanks Hi, To format number in Java you can use the class java.text.NumberFormat. Here is simple\nhow to count words in string using java\n++; } System.out.println(\"Number of words are: \"+count); } } Thanks Hello... count=0; String arr[]=st.split(\" \"); System.out.println(\"Number...how to count words in string using java how to count words in string\ncount characters\ncount characters i have to print the total number of char 'A' in all... sabah sarawak terengganu the output must be count the total number of char... main(String[] args) { int count=0; Scanner input=new Scanner\nMagic number Java Program\nMagic number Java Program write a program that guesses what number the user is thinking of. Below is a sample transcript: Think of a number between... the number, skip the next one, print the next one, skip the next one, etc\nModify the sales tax program to accept an arbitrary number of prices, total them, calculate the sales tax and print the total amount.\nModify the sales tax program to accept an arbitrary number of prices, total them, calculate the sales tax and print the total amount. Modify the sales tax program to accept an arbitrary number of prices, total them, calculate\ngetting random number in java\ngetting random number in java getting random number in java Hi... and scaling the random number in my Java Random number eample. but for some reason... to generate the random number in Java Thanks in Advance\nJava Print Dialog\nJava Print Dialog Using java.awt.print.PrinterJob and javax.print.attribute.PrintRequestAttributeSet. I call .printDialog(ps) and the standard print dialog is displayed with options preset to my chosen attributes. Now I can\nSimplest way to print an array in Java\nSimplest way to print an array in Java Simplest way to print an array in Java\nNSArray Count Example\nNSArray Count Example In the example, we are going to count the number of elements in an array in objective c programming. In Objective C language, Count is a primitive instance method that returns the number of objects available\nPHP SQL Number of Rows\n. To understand how to count the number of rows in a table, we have created a sql_num_rows.php..._rows(\\$res); print(\"\\$number_of_rows rows found\"... PHP SQL Number of Rows"
] | [
null,
"https://www.roseindia.net/d2/images/user_img.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.66728914,"math_prob":0.9125101,"size":6336,"snap":"2022-05-2022-21","text_gpt3_token_len":1611,"char_repetition_ratio":0.15208465,"word_repetition_ratio":0.084415585,"special_character_ratio":0.26120582,"punctuation_ratio":0.1736111,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98499453,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-05-20T03:49:39Z\",\"WARC-Record-ID\":\"<urn:uuid:7a729ffc-9c83-4ddd-8c75-b2db3d7e7896>\",\"Content-Length\":\"41849\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:fbbf389f-0021-46f3-a26a-072c0d6df09b>\",\"WARC-Concurrent-To\":\"<urn:uuid:9a3c85ab-c900-47eb-943d-347243131d89>\",\"WARC-IP-Address\":\"104.21.38.123\",\"WARC-Target-URI\":\"https://www.roseindia.net/answers/viewqa/Java-Beginners/18985-Count-number-of-occurences-and-print-names-alphabetically-in-Java.html\",\"WARC-Payload-Digest\":\"sha1:JRDIOVFKVU6LPUZSGYLEEBIOZFCFAJS4\",\"WARC-Block-Digest\":\"sha1:UBALWPIQW6TKDWIGANAHIG5B6OVFDP4S\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-21/CC-MAIN-2022-21_segments_1652662531352.50_warc_CC-MAIN-20220520030533-20220520060533-00113.warc.gz\"}"} |
https://mathspace.co/textbooks/syllabuses/Syllabus-411/topics/Topic-7310/subtopics/Subtopic-97529/?activeTab=theory | [
"",
null,
"New Zealand\nLevel 8 - NCEA Level 3\n\nExamine solutions to systems of equations in 3 unknowns\n\nLesson\n\nA system of three linear equations in three unknowns can have no solutions, one solution or infinitely many solutions. In this chapter, we explore the conditions for these three possibilities.\n\none equation\n\nA single linear equation in three unknowns represents a plane in a $3$3-dimensional coordinate system. For example, in the equation $3x-y+2z=0$3xy+2z=0, we could choose a fixed value for $z$z, say $z=t$z=t. Then, $y=3x-2t$y=3x2t. But this is the equation of a line in the $x$x-$y$y plane at the level of $t$t. There must be such a line at every possible level of $t$t and we might imagine these infinitely many lines, side by side, forming a plane in $3$3-space.\n\nExample 1\n\nThere are infinitely many sets of numbers $(x,y,z)$(x,y,z) that satisfy the equation $3x-y+2z=0$3xy+2z=0 but there are also infinitely many sets of numbers that do not satisfy the equation. We can specify the solution set by choosing a parameter $t$t for $z$z and another parameter $s$s for $y$y. Then, we see that $x$x is constrained by the equation to be $x=\\frac{1}{3}s-\\frac{2}{3}t$x=13s23t.\n\nThe solution set can be written in vector form as",
null,
"The two vectors on the right define a plane and the solution set is the set of linear combinations of the two vectors as $s$s and $t$t range over the real numbers.\n\ntwo equations\n\nTwo equations represent two planes. The planes might be parallel, in which case they have no points in common and there can be no solution that satisfies both equations. If the planes are not parallel, they intersect along a line and there are infinitely many solutions, all belonging to the line.\n\nExample 2\n\nThe equations $3x-y+2z=0$3xy+2z=0 and $3x-y+2z=6$3xy+2z=6 represent parallel planes. Any attempt at a simultaneous solution leads to an absurdity like $6=0$6=0 and we must conclude that no solution exists.\n\nOn the other hand, a pair of equations like $3x-y+2z=0$3xy+2z=0 and $x+y+z=0$x+y+z=0 can be solved to find a line of solutions. We might observe immediately that $(0,0,0)$(0,0,0) satisfies both equations. That is, both planes pass through the origin.\n\nWe could multiply the second equation by $-3$3 and add it to the first equation. This gives $0x-4y-z=0$0x4yz=0. We now have the equations $x+y+z=0$x+y+z=0 and $4y+z=0$4y+z=0 and these must have the same solution set as the original pair.\n\nAs before, we could choose to put $z=t$z=t. Then, from the $4y+z=0$4y+z=0 we find $y=-\\frac{t}{4}$y=t4. Finally, from $x+y+z=0$x+y+z=0 we have $x=\\frac{t}{4}-t=-\\frac{3t}{4}$x=t4t=3t4. All three variables have been expressed in terms of the single parameter $t$t.\n\nThis time, the solution set in vector form is",
null,
"The solution set is the set of scalar multiples of the vector on the right. The solution $(0,0,0)$(0,0,0) corresponds to $t=1$t=1.\n\nthree equations\n\nThree linear equations in three unknowns represent three planes in coordinate space. There are four possibilities.\n\n• All three may be parallel, in which case there is no intersection and no solution. The system of equations would be found to be inconsistent.\n• The three planes could intersect pairwise in three different parallel lines, in which case there is no simultaneous solution. Again, the system would be inconsistent.\n• All three could intersect in a single line so that there are infinitely many solutions. Solutions would be found as in Example 2.\n• The three planes could intersect at a single point.\n\nExample 3\n\nConsider the system of three equations",
null,
"If we subtract the first equation from the second and also subtract twice the first equation from the third, we obtain",
null,
"Next, subtract $\\frac{1}{2}$12 the second equation from the third.",
null,
"From the third of these equations, we find $z=5$z=5. Then, when this is substituted into the second equation, we get $y=3$y=3. And when these values of $z$z and $y$y are substituted into the first equation, we have $x=2$x=2.\n\nSo, the solution set is the single point",
null,
"There is a more efficient way of setting out these calculations, explained at this link.\n\nOutcomes\n\nM8-8\n\nForm and use systems of simultaneous equations, including three linear equations and three variables, and interpret the solutions in context\n\n91587\n\nApply systems of simultaneous equations in solving problems"
] | [
null,
"https://mathspace-production-static.mathspace.co/permalink/badges/v3/simultaneous-equations.svg",
null,
"https://mathspace-production-media.mathspace.co/media/upload/images/001_Chapter_Entries/Matrices/codecogseqn-48.gif",
null,
"https://mathspace-production-media.mathspace.co/media/upload/images/001_Chapter_Entries/Matrices/codecogseqn-49.gif",
null,
"https://mathspace-production-media.mathspace.co/media/upload/images/001_Chapter_Entries/Matrices/codecogseqn-50.gif",
null,
"https://mathspace-production-media.mathspace.co/media/upload/images/001_Chapter_Entries/Matrices/codecogseqn-51.gif",
null,
"https://mathspace-production-media.mathspace.co/media/upload/images/001_Chapter_Entries/Matrices/codecogseqn-52.gif",
null,
"https://mathspace-production-media.mathspace.co/media/upload/images/001_Chapter_Entries/Matrices/codecogseqn-53.gif",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.91047317,"math_prob":0.9998883,"size":3608,"snap":"2022-05-2022-21","text_gpt3_token_len":1018,"char_repetition_ratio":0.15926749,"word_repetition_ratio":0.021201413,"special_character_ratio":0.27134147,"punctuation_ratio":0.09259259,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":1.0000031,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14],"im_url_duplicate_count":[null,null,null,2,null,2,null,2,null,2,null,2,null,2,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-01-22T18:23:47Z\",\"WARC-Record-ID\":\"<urn:uuid:26172869-90e4-4355-ab90-11c473ea6550>\",\"Content-Length\":\"365677\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:7dd659f3-8971-491b-b2f6-dc2cbcfee5ad>\",\"WARC-Concurrent-To\":\"<urn:uuid:af67892b-378d-4d89-9440-0553b7cffae0>\",\"WARC-IP-Address\":\"104.22.56.207\",\"WARC-Target-URI\":\"https://mathspace.co/textbooks/syllabuses/Syllabus-411/topics/Topic-7310/subtopics/Subtopic-97529/?activeTab=theory\",\"WARC-Payload-Digest\":\"sha1:DHG622EV5VXAYQCTFIMXEHVNFZ4EUR5A\",\"WARC-Block-Digest\":\"sha1:GL3TPNXJKBLU3UDZHJ2EJY2IWQK4SXLY\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-05/CC-MAIN-2022-05_segments_1642320303868.98_warc_CC-MAIN-20220122164421-20220122194421-00005.warc.gz\"}"} |
https://search.r-project.org/CRAN/refmans/agridat/html/besag.beans.html | [
"besag.beans {agridat} R Documentation\n\n## Competition experiment in beans with height measurements\n\n### Description\n\nCompetition experiment in beans with height measurements\n\n### Usage\n\n`data(\"besag.beans\")`\n\n### Format\n\nA data frame with 152 observations on the following 6 variables.\n\n`gen`\n\ngenotype / variety\n\n`height`\n\nplot height, cm\n\n`yield`\n\nplot yield, g\n\n`row`\n\nrow / block\n\n`rep`\n\nreplicate factor\n\n`col`\n\ncolumn\n\n### Details\n\nField beans of regular height were grown beside shorter varieties. In each block, each variety occurred once as a left-side neighbor and once as a right-side neighbor of every variety (including itself). Border plots were placed at the ends of each block. Each block with 38 adjacent plots. Each plot was one row, 3 meters long with 50 cm spacing between rows. No gaps between plots. Spacing between plants was 6.7 cm. Four blocks (rows) were used, each with six replicates.\n\nPlot yield and height was recorded.\n\nKempton and Lockwood used models that adjusted yield according to the difference in height of neighboring plots.\n\nField length: 4 plots * 3m = 12m\n\nField width: 38 plots * 0.5 m = 19m\n\n### Source\n\nJulian Besag and Rob Kempton (1986). Statistical Analysis of Field Experiments Using Neighbouring Plots. Biometrics, 42, 231-251. Table 6. https://doi.org/10.2307/2531047\n\n### References\n\nKempton, RA and Lockwood, G. (1984). Inter-plot competition in variety trials of field beans (Vicia faba L.). The Journal of Agricultural Science, 103, 293–302.\n\n### Examples\n\n```## Not run:\n\nlibrary(agridat)\n\ndata(besag.beans)\ndat = besag.beans\n\nlibs(desplot)\ndesplot(dat, yield ~ col*row,\naspect=12/19, out1=row, out2=rep, num=gen, cex=1, # true aspect\nmain=\"besag.beans\")\n\nlibs(reshape2)\n# Add a covariate = excess height of neighbors\nmat <- acast(dat, row~col, value.var='height')\nmat2 <- matrix(NA, nrow=4, ncol=38)\nmat2[,2:37] <- (mat[,1:36] + mat[,3:38] - 2*mat[,2:37])\ndat2 <- melt(mat2)\ncolnames(dat2) <- c('row','col','cov')\ndat <- merge(dat, dat2)\n\n# Drop border plots\ndat <- subset(dat, rep != 'R0')\n\nlibs(lattice)\n# Plot yield vs neighbors height advantage\nxyplot(yield~cov, data=dat, group=gen,\nmain=\"besag.beans\",\nxlab=\"Mean excess heights of neighbor plots\",\nauto.key=list(columns=3))\n\n# Trial mean.\nmean(dat\\$yield) # 391 matches Kempton table 3\n\n# Mean excess height of neighbors for each genotype\n# tapply(dat\\$cov, dat\\$gen, mean)/2 # Matches Kempton table 4\n\n# Variety means, matches Kempton table 4 mean yield\nm1 <- lm(yield ~ -1 + gen, dat)\ncoef(m1)\n\n# Full model used by Kempton, eqn 5. Not perfectly clear.\n# Appears to include rep term, perhaps within block\ndat\\$blk <- factor(dat\\$row)\ndat\\$blkrep <- factor(paste(dat\\$blk, dat\\$rep))\nm2 <- lm(yield ~ -1 + gen + blkrep + cov, data=dat)\ncoef(m2) # slope 'cov' = -.72, while Kempton says -.79\n\n## End(Not run)\n```\n\n[Package agridat version 1.18 Index]"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.77101237,"math_prob":0.92932814,"size":2608,"snap":"2021-31-2021-39","text_gpt3_token_len":756,"char_repetition_ratio":0.1140553,"word_repetition_ratio":0.0051150895,"special_character_ratio":0.30329755,"punctuation_ratio":0.17110266,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99278426,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-07-27T03:13:49Z\",\"WARC-Record-ID\":\"<urn:uuid:d2883474-0568-4153-b066-3bd18ff2c947>\",\"Content-Length\":\"4393\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:f440b8b2-7189-4240-ab97-4f9824a0cd11>\",\"WARC-Concurrent-To\":\"<urn:uuid:a6be5848-8b59-44cb-ac4b-773e4655a56d>\",\"WARC-IP-Address\":\"137.208.57.46\",\"WARC-Target-URI\":\"https://search.r-project.org/CRAN/refmans/agridat/html/besag.beans.html\",\"WARC-Payload-Digest\":\"sha1:73UW3Y6USBVOWKN7WLYMPQJM7NDAA3UF\",\"WARC-Block-Digest\":\"sha1:PRPT6KRRTZXSM2CBNTO5BQXG36ZDXEF3\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-31/CC-MAIN-2021-31_segments_1627046152168.38_warc_CC-MAIN-20210727010203-20210727040203-00360.warc.gz\"}"} |
https://www.dst.defence.gov.au/publication/magnetic-signatures-spherical-bodies-earth%E2%80%99s-magnetic-field-%E2%80%94-comparison-analytical-and | [
"# Technical report |Magnetic signatures of spherical bodies in Earth’s magnetic field — a comparison of analytical and finite element analysis solutions\n\n### Abstract\n\nCalculating magnetic signatures using analytical techniques becomes infeasible for complex geometries such as submarines, hence numerical techniques, such as finite element analysis, must be used instead. In this report we compare analytical and finite element solutions utilising COMSOL for calculating the magnetic induction of a permeable spherical shell with an internal current band in uniform magnetic induction. The analytical and finite element analysis solutions were found to be approximately equal, this verifies that modelling of magnetic signatures of submarines using COMSOL will generate correct data.\n\n### Executive Summary\n\nIn this report we compare analytical and finite element solutions to validate the use of COMSOL software for calculating the magnetic signature of permeable materials with current bands in background magnetic fields.\n\nThe analytical techniques used for determining the magnetic signature of a simple shape, such as a spherical shell, cannot be used to calculate the magnetic signature of a submarine due to its complex structure. Instead, the magnetic signature of a submarine must be numerically calculated using finite element analysis. However, finite element analysis introduces both discretisation and numerical errors. This report quantifies these errors. The magnetic signature is calculated for the following domains:\n\n• a permeable spherical shell in uniform magnetic induction B0\n• a permeable spherical shell with an internal current band\n• a permeable spherical shell with an internal current band in uniform magnetic induction B0.\n\nThe finite element solutions were found to closely approximate the analytical solutions. These solutions may be used to study the induced magnetic signatures of ferromagnetic bodies and coils found on modern submarines. COMSOL may be used to calculate the magnetic induction of permeable materials with internal current bands in background magnetic fields.\n\n### Author\n\nRyan Michael Thomas\n\n### Publication number\n\nDST-Group-TR-3530\n\nTechnical report\n\nSeptember 2018\n\n### Classification\n\nUnclassified - public release\n\n### Keywords\n\nMagnetic signature, magnetic induction, spherical shell",
null,
"DST-Group-TR-3530.pdf"
] | [
null,
"https://www.dst.defence.gov.au/modules/file/icons/application-pdf.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8674082,"math_prob":0.9176763,"size":2094,"snap":"2022-27-2022-33","text_gpt3_token_len":355,"char_repetition_ratio":0.1598086,"word_repetition_ratio":0.17785235,"special_character_ratio":0.15759312,"punctuation_ratio":0.06583072,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98646444,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-06-27T23:33:52Z\",\"WARC-Record-ID\":\"<urn:uuid:0d6838c9-cb27-47f8-849e-b513b3e4d7ea>\",\"Content-Length\":\"77698\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:93544cdf-c3aa-4090-854b-37fcb2213661>\",\"WARC-Concurrent-To\":\"<urn:uuid:849a49d2-11ef-477d-9933-9df9301a97dd>\",\"WARC-IP-Address\":\"13.54.208.113\",\"WARC-Target-URI\":\"https://www.dst.defence.gov.au/publication/magnetic-signatures-spherical-bodies-earth%E2%80%99s-magnetic-field-%E2%80%94-comparison-analytical-and\",\"WARC-Payload-Digest\":\"sha1:X5KJGTO6BNPG4N722RNHDVVYMX7RPQOG\",\"WARC-Block-Digest\":\"sha1:VCZ5KC7TICENZJJLOLR6MJMJ4CIH2WKE\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-27/CC-MAIN-2022-27_segments_1656103344783.24_warc_CC-MAIN-20220627225823-20220628015823-00448.warc.gz\"}"} |
https://sdctools.github.io/sdcTable/articles/sdcTable.html | [
"# sdcTable Vignette\n\nThe purpose of the sdcTable vignette is to show how to get up and running with sdcTable; for details, including a complete list of options, consult the help pages or the manual for the following main functions of the package:\n\n• makeProblem using e.g: help('makeProblem') or ?makeProblem\n• primarySuppression using e.g: help('primarySuppression') or ?primarySuppression\n• protectTable using e.g: help('protectTable') or ?protectTable\n• setInfo using e.g: help('setInfo') or ?setInfo\n• getInfo using e.g: help('getInfo') or ?getInfo\n\n## How to protect data - An overview",
null,
"Figure 1: sdcTable - an overview of exported functions\n\nThe main functions that are exported to users are shown in Figure 1.\n\nFunction makeProblem() is used to create objects of class sdcProblem. Instances of class sdcProblem hold the entire information that is required to perform primary or secondary cell suppression such as assumed to be known upper and lower cell bounds or upper-, lower- or sliding protection levels that are required to fulfill when solving the secondary cell suppression problem. All this information can be modified using function setInfo().\n\nprimarySuppression() is applied to objects of class sdcProblem. By setting function parameters users can choose and apply a pre-defined primary suppression rule. Using setInfo(), one can easily implement a custom primary suppression rule, too.\n\nFunction protectTable() is used to protect primary sensitive table cells in objects of class sdcProblem. A successful run of function protectTable() results in an object of class safeObj. Using getInfo() one can extract information from objects of such class, most importantly of course a data set containing all table cells along with the suppression pattern.\n\nMore detailed information on all the possibilities is available in the help-files, additional information is given in the corresponding sections of this vignette that deal with specific functions. The first step however to get started is to load the package, which can easily be done as shown below:\n\nlibrary(sdcTable)\npackageVersion(\"sdcTable\")\n## '0.31.1'\n\n# A simple example\n\nWe now walk through the steps that are required to protect tabular data using sdcTable. In the first example we are going to protect table cells given a three-dimensional tabular structure with some sub-totals.\n\nWe will start by discussing input data sets in sections “Starting from microdata” and “Using aggregated data”. Then we continue by discussing how to define and describe dimensional variables in “Defining hierarchies” which is a crucial step in the entire procedure. Once the hierarchies are defined it is necessary to create suitable objects as described (here) that can be used to identify and suppress primary sensitive cells. This is shown in section “Identifying sensitive cells”. Finally we discuss how to “protect primary sensitive table cells”.\n\nThroughout it is also shown how to set and extract information from the objects we are working with using functions getInfo() and setInfo().\n\n### Starting from microdata\n\nIn this example we suppose we have collected data from 1000 individuals. A subset of the available data is shown below:\n\n## V1 V2 V3 numVal2 numVal1\n## A w d 49.93 71.72\n## C m f 48.44 55.96\n## Ba m a 43.20 64.69\n## Bc w d 31.38 30.72\n## Bc w a 49.46 54.93\n## Ba m d 42.02 22.23\n\nWe note that the information we have obtained for any individual corresponds to exactly one row in the input data.frame. That is supposed to be available in R.\n\nThe micro data consist of 5 variables. The first 3 variables (V1, V2 and V3) are categorical variables that will later define the table that needs to be protected. Variables ‘numVal1’ and ‘numVal2’ correspond to arbitrary variables containing some kind of information measured for each individual.\n\nTo create the tabular structure that is required to protect any table cells within the table it is of course of interest to have a look at possible values or characteristics of the categorical variables that define the table.\n\n• Variable V1: this variable has a total of 6 codes without subtotals which are listed below:\n## \"A\" \"Ba\" \"Bb\" \"Bc\" \"C\" \"D\"\n• Variable V2: this variable has a total of 2 codes without subtotals which are listed below:\n## \"m\" \"w\"\n• Variable V3: this variable has a total of 6 codes without subtotals which are listed below:\n## \"a\" \"b\" \"c\" \"d\" \"e\" \"f\"\n\nThe step on how to define level-hierarchies that have to include all possible (sub)totals is explained below.\n\n### Using aggregated data\n\nUsing sdcTable it is also possible to start with a ‘complete’ dataset. This means that the input dataset already contains rows with all possible level-combinations that can occur. This also includes combinations with (sub)totals. In this case it is required that the input data contain a column holding cell counts. Using the example data already discussed in section “Starting from microdata”, the complete dataset could be specified as shown below:\n\nprint(tail(completeData))\n## V1 V2 V3 Freq numVal1 numVal2\n## 163 C Tot f 24 7523.30 7305.85\n## 164 D Tot f 31 7723.40 7698.75\n## 165 Tot m f 107 24033.37 24325.32\n## 166 B m f 55 12797.11 13372.83\n## 167 Tot w f 85 25082.25 25459.33\n## 168 B w f 50 12600.68 12861.13\n\nEven though we only show a small subset of the data it is immediately clear that in object completeData (sub)totals are listed. These combinations can be calculated from the microdata by summation over several codes in one or more dimensional variables. As in section Starting from microdata it is of interest which codes were specified for each dimensional variable. This information is given below:\n\n• Variable V1: this variable has a total of 8 codes including all possible subtotals which are listed below:\n## \"Tot\" \"A\" \"B\" \"Ba\" \"Bb\" \"Bc\" \"C\" \"D\"\n• Variable V2: this variable has a total of 3 codes including all possible subtotals which are listed below:\n## \"Tot\" \"m\" \"w\"\n• Variable V3: this variable has a total of 7 codes including all possible subtotals which are listed below:\n## \"Tot\" \"a\" \"b\" \"c\" \"d\" \"e\" \"f\"\n\nWe also note that in completeData a variable Freq is available which gives information on the corresponding cell counts. This means that for example a total of 50 individuals contribute to the table cell where variable V1 equals B, variable V2 is w and variable V3 is equal to f.\n\nWhether or not one starts to work with micro data or already with a complete, pre-aggregated dataset the next step is always the definition of the hierarchies defining the tabular structure.\n\n### Defining hierarchies\n\nWe could see here (for micro data) and here (for pre-aggregated data) that the set of codes available in the input data for variables V1, V2 and V3 differ since in the case where micro data are used as input data, no codes for subtotals are included in the micro data while in the case where pre-aggregated data are used those subtotals must already be included in the input data set.\n\nWhen defining the complete hierarchies, no (sub)-totals must be excluded from the description. This means that for each variable defining one dimension of the table the complete structure must of course includes all (sub)totals.\n\nIn this example the hierarchies we want to define are quite basic. We start by showing the level-codes for each variable V1, V2 and V3 that are included in completeData but not in microData.\n\n• (sub)totals of variable V1:\n## \"Tot\" \"B\"\n• (sub)totals of variable V2:\n## \"Tot\"\n• (sub)totals of variable V3:\n## \"Tot\"\n\nWe observe that variable V1 has two codes (Tot and B) that can be calculated from the codes of V1 available in the micro data set microData. For variables V2 and V3 only one total value (Tot) exists which means the summation over all characteristics of variables V2 and V3 is the (only) total value. To specify the complete structure of a dimensional variable one needs to create a data frame or a matrix for each of those variables. The structure of any object describing a dimensional variable be created as follows:\n\n• the object must consist of exactly 2 columns, both being character vectors\n• the first column specifies levels\n• the second column specifies level-codes\n• the only allowed character in the first column is @\n• the length of the strings of the first column defines the (numeric) level of the corresponding code\n• a top-down approach has to be taken\n• the object must contain a row for each possible level-code\n\nWhile this may sound difficult, it is in fact quite easy to create such objects within R. We will now explain how to create the required objects for the dimensional variables V1, V2 and V3 used in the example.\n\n#### defining level-structure for variable V1\n\nThe hierarchy we want to describe is as follows. The overall code Tot is calculated from the codes (A, B, C and D). Additionally, code B (which is the second (sub)total-code for variable V1 as described here) can be calculated from the level-codes Ba, Bb and Bc.\n\nFollowing rule 1, we have to create a data frame or matrix consisting of two columns, the first specifying levels, the second column the corresponding level codes. Since we have to follow a top-down approach, the first level code must always correspond to the grand total which is always considered as the code with a level equaling 1. Thus, we create the matrix with a single row defining the overall total as follows:\n\ndimV1 <- matrix(nrow = 0, ncol = 2)\ndimV1 <- rbind(dimV1, c(\"@\", \"Tot\"))\nprint(dimV1)\n## [,1] [,2]\n## [1,] \"@\" \"Tot\"\n\nThe level code for the overall total is @ because according to rule 4 it is the only allowed character in the first column and it consists of exactly 1 character. Also, since the overall total is defined as level 1, the number of characters of the string @ and the level of the overall total code Tot matches.\n\nThe next step is to add additional codes. As mentioned before, codes A, B, C and D contribute the the overall total. Therefore we know that these codes are considered as level 2 codes and must be (according to the top-down approach) listed below the overall total code. Adding these codes to object dimV1 is shown below:\n\nmat <- matrix(nrow = 4, ncol = 2)\nmat[, 1] <- rep(\"@@\", 4)\nmat[, 2] <- LETTERS[1:4]\ndimV1 <- rbind(dimV1, mat)\nprint(dimV1)\n## [,1] [,2]\n## [1,] \"@\" \"Tot\"\n## [2,] \"@@\" \"A\"\n## [3,] \"@@\" \"B\"\n## [4,] \"@@\" \"C\"\n## [5,] \"@@\" \"D\"\n\nWe know that code B is a subtotal that can be calculated from codes Ba, Bb and Bc. Since B is a code of level 2, the codes contributing to it must be of a lower level, in this case of level 3. We show below how to add the codes to object dimV1:\n\nmat <- matrix(nrow = 3, ncol = 2)\nmat[, 1] <- rep(\"@@@\", 3)\nmat[, 2] <- c(\"Ba\", \"Bb\", \"Bc\")\n\ndimV1 <- rbind(dimV1, mat)\nprint(dimV1)\n## [,1] [,2]\n## [1,] \"@\" \"Tot\"\n## [2,] \"@@\" \"A\"\n## [3,] \"@@\" \"B\"\n## [4,] \"@@\" \"C\"\n## [5,] \"@@\" \"D\"\n## [6,] \"@@@\" \"Ba\"\n## [7,] \"@@@\" \"Bb\"\n## [8,] \"@@@\" \"Bc\"\n\nNow object dimV1 contains all possible codes along with their levels. However, it not valid because the top-down approach is violated. This means that codes that contribute to a (sub)total must be listed directly below it. If we would not change the order of object dimV1, sdcTable would assume that code D can be calculated by summation over codes Ba, Bb and Bc. For this reason it is necessary to move this “block” up so that it is directly below code B. The required code and the resulting correct object describing the structure of variable V1 is printed below:\n\ndimV1 <- dimV1[c(1:3,6:8, 4:5),]\nprint(dimV1, row.names = FALSE)\n## [,1] [,2]\n## [1,] \"@\" \"Tot\"\n## [2,] \"@@\" \"A\"\n## [3,] \"@@\" \"B\"\n## [4,] \"@@@\" \"Ba\"\n## [5,] \"@@@\" \"Bb\"\n## [6,] \"@@@\" \"Bc\"\n## [7,] \"@@\" \"C\"\n## [8,] \"@@\" \"D\"\n\nUsing this information, sdcTable internally calculates all kinds of information on dimensional variables. So for example it is able to deal with codes that can be (temporarily) removed from the structure because it can be considered as a “duplicate”. This is however not the case for this basic dimensional variable that has a total of 8 codes of which 6 are required to calculate information for the 2 (sub)totals.\n\nSince versions >= 0.27, sdcTable allows to use inputs created from package sdcHierarchies as input. This package allows for a very simple way to create, compute and modify hierarchies. For a complete introduction, the package vignette can be viewed with hier_vignette(). The main functions are hier_create(), hier_add(), hier_rename() and hier_delete(). We now show an alternative way to generate the hierarchy for variable V1.\n\ndimV1 <- hier_create(root = \"Tot\", nodes = LETTERS[1:4])\ndimV1 <- hier_add(dimV1, root = \"B\", nodes = c(\"Ba\",\"Bb\",\"Bc\"))\nhier_display(dimV1)\n## Tot\n## ├─A\n## ├─B\n## │ ├─Ba\n## │ ├─Bb\n## │ └─Bc\n## ├─C\n## └─D\n\nsdcTable will internally convert the tree-based structure generated using functionality from the sdcHierarchies package automatically into the data.frame based structure discussed at the begin of this section.\n\n#### defining level-structure for variable V2\n\nThe creation of a suitable object that describes the hierarchical structure of variable V2 is easy. We are only dealing with one overall Total (Tot) that is the sum of all codes listed here for this variable.\n\nThe code how to specify an object that describes the structure of dimensional variable V2 is given below:\n\ndimV2 <- hier_create(root = \"Tot\", nodes = c(\"m\", \"w\"))\nhier_display(dimV2)\n## Tot\n## ├─m\n## └─w\n\nWe see that the overall total (Tot) is again listed in the first row with the two other contributing codes (m and w) being below in the same hierarchy level.\n\n#### defining level-structure for variable V3\n\nThe creation of a suitable object that describes the hierarchical structure of variable V3 is easy. We are only dealing with one overall Total (Tot) that is the sum of all codes listed here for variable V3.\n\nThe required code to generate an object specifying the hierarchical structure of variable V3 is given below:\n\ndimV3 <- hier_create(root = \"Tot\", nodes = letters[1:6])\nhier_display(dimV3)\n## Tot\n## ├─a\n## ├─b\n## ├─c\n## ├─d\n## ├─e\n## └─f\n\nIt is required to create an object defining the complete structure and hierarchies for each dimensional variable. Once this step has been done, the multidimensional tabular structure that is required to apply any statistical disclosure methods can be created using makeProblem().\n\n### Creating objects of class sdcProblem for further processing\n\nWe now show how to create objects of class sdcProblem which can further be used to identify, suppress and protect sensitive table cells.\n\nIt was discussed here and here how micro data and pre-aggregated data can be used as data-input objects. We will now explain how to create instances of class sdcProblem from both microData and completeData and describe the required and optional parameters of function makeProblem().\n\nWe start building a suitable object of class sdcProblem starting with the data on individual level available from object microData.\n\ndimList <- list(V1 = dimV1, V2 = dimV2, V3 = dimV3)\nprob.microDat <- makeProblem(\ndata = microData,\ndimList = dimList,\ndimVarInd = 1:3,\nfreqVarInd = NULL,\nnumVarInd = 4:5,\nweightInd = NULL,\nsampWeightInd = NULL)\n\nFirst we have to combine the objects describing the hierarchical variables V1, V2 and V3 into a list-object named dimList. Each list element is one of the objects created in section “Defining hierarchies”. The names of the list-elements must correspond to the variable name that the corresponding list-element refers to. In this case, the first list-element - dimV1 - should describe variable V1 in the input data set microData when calling makeProblem() while the second list element - dimV2 - defines the hierarchy of variable V2 and dimV3 - the third list element - describes the structure of variable V3.\n\nThe remaining parameters are quite self-explanatory and shorty described below:\n\n• data: the data set that should be used, in this case microData\n• dimList: a named list containing information on the structure of dimensional variables as described just above\n• dimVarInd: the column indices of dimensional described in dimList.\n• freqVarInd: if not NULL, an index specifying the column that contains information on cell counts\n• numVarInd: if not NULL, an index specifying the columns holding other numerical variables\n• weightInd: if not NULL, an index specifying the column that contains info on weights that should be used in the secondary cell suppression problem instead of cell counts\n• sampWeightInd: if not NULL, an index specifying the column holding sampling weights for each person/group\n\nBuilding an object of class sdcProblem using the complete, pre-aggregated data completeData as discussed above is very similar as it is shown below:\n\n### problem from complete data ###\ndimList <- list(V1 = dimV1, V2 = dimV2, V3 = dimV3)\nprob.completeDat <- makeProblem(\ndata = completeData,\ndimList = dimList,\ndimVarInd = 1:3,\nfreqVarInd = 4,\nnumVarInd = 5:6,\nweightInd = NULL,\nsampWeightInd = NULL)\n\nThe only difference is that in this case we define parameter ‘freqVarInd’ that specifies a column within the input data set {completeData} containing information on cell counts. Also the indices of argument numVarInd are different to the first example.\n\nIn any case, both procedures return an object of class sdcProblem as it can easily be checked:\n\nall(c(class(prob.microDat), class(prob.completeDat)) == \"sdcProblem\")\n## TRUE\n\nWe now can check if the cell counts of both objects are equal. Function getInfo() can be used to extract information from objects of class sdcProblem. Specifying argument type as freq, getInfo() returns cell counts which are indeed equal independently if micro-data or pre-aggregated data have been used as input to create the complete tabular structure.\n\ncounts1 <- getInfo(prob.completeDat, type = \"freq\")\ncounts2 <- getInfo(prob.microDat, type = \"freq\")\nall(counts1 == counts2)\n## TRUE\n\nOnce the problem has been set up and an instance of class {sdcProblem} is available, it is possible to identify and suppress sensitive table cells as we demonstrate in the next section using object prob.completeDat.\n\n### Identifying sensitive cells\n\nIdentifying and suppressing primary sensitive cells is usually done by applying function primarySuppression().\n\nHaving a look at the cell counts in table prob.completeDat shows that a total of 15 cells have less than 10 individuals contributing to it. We think that these cells should be considered as primary sensitive and we want to have them protected.\n\nWhen creating an object of class sdcProblem, all cells are assigned an anonymization state. The possible codes are listed below:\n\n• \"u\": cell is primary suppressed and needs to be protected\n• \"x\": cell has been secondary suppressed\n• \"s\": cell can be published\n• \"z\": cell must not be suppressed\n\nThe goal is now to change the anonymization status of all cells having less than 10 individuals contributing to it from the default value of s to u. The easiest way is to use function primarySuppression() directly:\n\nprob.completeDat <- primarySuppression(prob.completeDat, type = \"freq\", maxN = 10)\n\nArgument type specifies the primary suppression rule we want to apply. In this case we want to use the frequency threshold rule that allows to suppress all table cells having cell counts less or equal than the threshold specified using argument maxN. primarySuppression() also allows to apply the nk-dominance rule or the p-percent rule directly, in case micro data have been used as input data. For all possible parameters and their explanation the interested reader may consult the manual or the help-page of primarySuppression().\n\nAfter performing the suppression, we can have a look at the distribution of the anonymization states:\n\nprint(table(getInfo(prob.completeDat, type = \"sdcStatus\")))\n##\n## s u\n## 153 15\nsummary(prob.completeDat)\n## The raw data contain pre-aggregated (tabular) data!\n##\n## The complete table to protect consists of 168 cells and has 3 spanning variables.\n## The distribution of\n## - primary unsafe (u)\n## - secondary suppressed (x)\n## - forced to publish (z) and\n## - selectable for secondary suppression (s) cells is shown below:\n##\n## s u\n## 153 15\n##\n## If this table is protected with heuristic methods, a total of 12 has (sub)tables must be considered!\n\nOne can see that the 15 cells having counts less or equal than 10 have been identified and marked as primary suppressed. However, we should note that it is very easy to implement custom suppression rules by manually changing the anonymization state of cells using functions setInfo() or changeCellStatus(). Information on how to use these functions is of course provided in the manual and the corresponding help-pages.\n\nTo protect these cells by solving the secondary cell suppression problem one can go on to use function protectTable() as explained in the next section.\n\n### Secondary cell suppression using sdcTable\n\nsdcTable provides the algorithms to protect primary sensitive table cells within objects of class sdcProblem. The algorithms that may be selected are:\n\n• “OPT”: protect the complete hierarchical, multidimensional table at once. This algorithm is however only suitable for small problem instances.\n• “HITAS”: solving the secondary cell suppression problem by applying a cut and branch algorithm to subtables that are protected in specific order\n• “HYPERCUBE”: solving the problem using a heuristic that is based on finding geometric hypercubes that are required to protect primary sensitive table cells\n• “SIMPLEHEURISTIC”: solving the problem using a fast heuristic approach that only protects against exact recalculation of values\n\nWe show how to protect the data using the available algorithms. For an extensive discussion on the possible parameters have a look at the manual or help page for function protectTable().\n\nresHITAS <- protectTable(prob.completeDat, method = \"HITAS\")\nresOPT <- protectTable(prob.completeDat, method = \"OPT\")\nresHYPER <- protectTable(prob.completeDat, method = \"HYPERCUBE\")\nresSIMPLE <- protectTable(prob.completeDat, method = \"SIMPLEHEURISTIC\")\n\nHaving a look at the Output objects we can observe that the number of secondary suppressions required to protect the 15 primary sensitive cells (by default against exact re-calculation given sliding protection levels of 1 for each primary sensitive cell) differs.\n\nUsing the “OPT”-algorithm, a total of 23 cells have been marked as secondary suppressions. When using “HITAS”-algorithm, it was required to additionally suppress 25 cells. A total of 29 cells was selected and marked as secondary suppressions when the “HYPERCUBE” algorithm was used while 31 additional suppressions were required for the fast heuristic simple procedure “SIMPLEHEURISTIC”.\n\nOne now easily get information from the resulting output objects that are instances of class safeObj by using function getInfo() or applying the summary-method. For the former we show how to extract the final data set which can be achieved as follows:\n\nfinalData <- getInfo(resOPT, type = \"finalData\")\nprint(head(finalData))\n## V1 V2 V3 Freq numVal1 numVal2 sdcStatus\n## 1 A m a 12 3919.84 4090.31 s\n## 2 Ba m a 18 4707.53 5101.81 s\n## 3 Bb m a 18 4199.31 4186.62 x\n## 4 Bc m a 10 3890.27 4084.40 u\n## 5 C m a 11 3341.39 2988.84 s\n## 6 D m a 13 3975.03 3873.34 s\n\nAs we can see above the final result data set contains all columns specified in the input data set along with another column sdcStatus that specifies the anonymization state for each table cell.\n\nFor the latter we show how to apply the summary method. This can be done by applying the following code:\n\nsummary(resOPT)\n##\n## ######################################################\n## ### Summary of the result object of class 'safeObj' ###\n## ######################################################\n## --> The input data have been protected using algorithm OPT.\n## --> The algorithm ran for 45 seconds.\n## --> To protect 15 primary sensitive cells, 23 cells need to be additionally suppressed.\n## --> A total of 130 cells may be published.\n##\n## ###################################\n## ### Structure of protected Data ###\n## ###################################\n## 'data.frame': 168 obs. of 7 variables:\n## $V1 : Factor w/ 8 levels \"A\",\"B\",\"Ba\",\"Bb\",..: 1 3 4 5 6 7 1 3 4 5 ... ##$ V2 : Factor w/ 3 levels \"m\",\"Tot\",\"w\": 1 1 1 1 1 1 3 3 3 3 ...\n## $V3 : Factor w/ 7 levels \"a\",\"b\",\"c\",\"d\",..: 1 1 1 1 1 1 1 1 1 1 ... ##$ Freq : num 12 18 18 10 11 13 19 12 12 18 ...\n## $numVal1 : num 3920 4708 4199 3890 3341 ... ##$ numVal2 : num 4090 5102 4187 4084 2989 ...\n## \\$ sdcStatus: chr \"s\" \"s\" \"x\" \"u\" ...\n## NULL\n\nWe see that the summary provides all kind of useful information such as the algorithm that has been used to protect primary sensitive cells, the time it has been taken to solve the problem, the number of primary sensitive and secondary suppressed cells as well as the number of cells that may be published. Also, a excerpt of the final data set is shown.\n\nI would also like to mention that an iterative algorithm is available in function protectLinkedTables() that allows to protect two tables that have common table cells. The function takes two objects of class sdcProblem as input and a list defining the common cells in both tables. Details on how to construct this a list-element are given in the manual and help-page of protectLinkedTables().\n\n# Remarks\n\nA lot of work has gone into the rewrite of sdcTable using S4-classes and methods in order to robustify the code and in order to make it easier in future to add new algorithms such as rounding- or cell-perturbation methods and features.\n\nI would really like to hear any kind of feedback and will be more than happy to work in patches you submit or ideas any one might have which would make it easier to work sdcTable. Also, the next step in the evolution of the package will be performance optimization, evaluation for possibilities of parallel computing and so on. I would really like to hear any kind of feedback on package users on these kind of things. Thus, for any remarks, please do not hesitate to contact me using my e-mail adress [email protected]."
] | [
null,
"https://sdctools.github.io/sdcTable/articles/overview.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.83084315,"math_prob":0.9294868,"size":24197,"snap":"2020-45-2020-50","text_gpt3_token_len":6073,"char_repetition_ratio":0.13503906,"word_repetition_ratio":0.09425733,"special_character_ratio":0.26623136,"punctuation_ratio":0.103626944,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9699881,"pos_list":[0,1,2],"im_url_duplicate_count":[null,1,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-12-03T11:35:08Z\",\"WARC-Record-ID\":\"<urn:uuid:38700f66-f196-4979-871d-fe35d5e987bb>\",\"Content-Length\":\"52880\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:11b5a4e7-ec22-43dc-ba41-ec9f7d9075b2>\",\"WARC-Concurrent-To\":\"<urn:uuid:6ea0ce6d-bdf4-4806-b044-170290785bef>\",\"WARC-IP-Address\":\"185.199.108.153\",\"WARC-Target-URI\":\"https://sdctools.github.io/sdcTable/articles/sdcTable.html\",\"WARC-Payload-Digest\":\"sha1:AGUN7WVQQQUI7WSWZRIPPQ7VXGQNV7VD\",\"WARC-Block-Digest\":\"sha1:D6MQWWH3AZCJ36ZJD6XIBMGTNW3AXFDU\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-50/CC-MAIN-2020-50_segments_1606141727627.70_warc_CC-MAIN-20201203094119-20201203124119-00475.warc.gz\"}"} |
https://m.rbi.org.in/Scripts/PublicationsView.aspx?id=9493 | [
"#",
null,
"## publications",
null,
"(375 kb)\nDate : Aug 01, 2007\nIX. Estimation of Seasonal Factors\n 9.1. Introduction Economic time series are generally found to exhibit regular, intra-year seasonal movements around its annual trend path. Such repetitive seasonal variations can result from climatic conditions, production cycle characteristics, seasonal nature of economic activity, festivals, vacation practices, etc. While the seasonal variations occur regularly, yet they may vary in magnitude from year to year. From the policy perspective, information on seasonal factors of an economic variable is useful as it enables the policy maker to differentiate between the seasonal changes and long-run changes in a variable and thereby design appropriate policy responses. An article regarding monthly seasonal factors for selected economic and financial time series of the Indian economy is being regularly published in the RBI Bulletin from 1980 onwards. This article presents the monthly seasonal factors of selected economic/financial time series classified into major five groups, namely, A. Monetary and Banking Indicators; B. Wholesale Price Index (WPI); C. Consumer Price Index for Industrial workers (CPI-IW); D. Index of Industrial Production (IIP); E. External Trade. The seasonal factors are being estimated using the X-12 auto-regressive integrated moving average (ARIMA) methodology. X-12 ARIMA is the software for seasonal adjustment developed by the US Census Bureau. It is an enhanced version of the X-11 Variant of the Census Method II seasonal adjustment programme. The procedure makes multiplicative/additive adjustments of a time series and creates an output data set containing the adjusted time series and intermediate calculations. The main source of these new tools is the extensive set of time series model building facilities built into the programme for fitting the regARIMA models. These are regression models with ARIMA (Autoregressive Integrated Moving Average) errors. More precisely, they are models in which the mean function of the time series (or its lags) is described by a linear combination of regressors, and the covariance structure of the series is that of an ARIMA process. If no regressors are used, indicating that the mean is assumed to be zero, the regARIMA model reduces to an ARIMA model. There are regressors for modeling certain kinds of disruption in the series, or sudden changes in level, whose effects need to be removed from the data before the methodology can adequately estimate seasonal adjustments. The regARIMA-modeling module of X-12-ARIMA was adopted from the regARIMA programme developed by the Time Series Staff of Census Bureau’s Statistical Research Division. 9.2. Methodology The X-12-ARIMA is developed following the operation-flow diagram of Figure 9.1. This posits a regARIMA (linear regression model with ARIMA time series errors) modeling subprogram that can provide forecasts, backcasts, and prior adjustments for various effects before the seasonal adjustment subprogram in the central box is invoked. The final box in Figure 9.1 represents a set of post-adjustment diagnostic routines that can be used to obtain indicators of the effectiveness of both the modeling and the seasonal adjustment options chosen. The modeling module of X-12-ARIMA is designed for regARIMA model building with seasonal economic time series. To this end, several categories of predefined regression variables are available in X-12-ARIMA (for further details user may refer to the manual available at ‘htttp://www.census.gov/srd/www/ x12a/). User-defined regression variables can also be easily read in and included in models. For a multiplicative model, Figure 9.2 describes X-12 process for computing seasonal factors. X-12-ARIMA uses the standard (p d q) (P D Q)s notation for seasonal ARIMA models. The (p d q) refers to the orders of the nonseasonal autoregressive (AR), differencing, and moving average (MA) operators, respectively. The (P D Q)s refers to the seasonal autoregressive, differencing, and moving average orders. The s subscript denotes the seasonal period, e.g., s = 12 for monthly data, or 4 for quarterly data. Great flexibility is allowed in the specification of the ARIMA structures: any number of AR, MA, and differencing operators may be used; missing lags are allowed in AR and MA operators; and AR and MA parameters can be fixed at user-specified values. The specification of a regARIMA model requires specification both of regression variables to be included in the model and also the type of ARIMA model for regression errors (i.e., the orders (p d q) (P D Q)s). Specification of the regression variables depends on user knowledge about the series being modelled. For the user who wishes to fit customised time series models, X-12-ARIMA provides capabilities for the three modeling stages of identification, estimation, and diagnostic checking. Identification of the ARIMA model for the regression errors follows well-established procedures based on examination of various sample autocorrelation and partial autocorrelation functions produced by X-12-ARIMA. Once a regARIMA model has been specified, X-12-ARIMA will estimate its parameters by maximum likelihood using an iterative generalised least squares (IGLS) algorithm. Diagnostic checking involves estimation of residuals from the fitted model for signs of model inadequacy. The major improvements in X-12 ARIMA are new modeling capabilities using regARIMA models, sliding spans diagnostic procedure, ability to produce revisions history of a given seasonal adjustment, several new outlier detection options for the irregular component of the seasonal adjustment, etc. RegARIMA is a linear regression model with ARIMA that can provide forecasts and prior adjustments for various effects. X-12 ARIMA uses regARIMA models to preadjust a series by removing effects such as outliers, etc., before the seasonal adjustment program is invoked.",
null,
"",
null,
"",
null,
"",
null,
"",
null,
"residuals (with standard errors), along with Ljung and Box (1978) summary Q-statistics. X-12-ARIMA can also produce basic descriptive statistics of the residuals and a histogram of the standardised residuals. An important aspect of diagnostic checking of time series models is outlier detection. The outlier spec of X-12-ARIMA provides the automatic detection of additive outliers (AOs), temporary change outliers (TCs) and level shifts (LSs). X-12-ARIMA’s approach of outliers detection involves computing t-statistics for significance of each outlier type at each time point, searching through these t-statistics for significant outlier(s), and adding the corresponding AO, LS, or TC regression variable(s) to the model. A seasonal adjustment that leaves detectable residual seasonal and calendar effects in the adjusted series is usually regarded as unsatisfactory. Even if no residual effects are detected, the adjustment will be unsatisfactory if the adjusted values (or important derivative statistics, such as the percent changes from one month to the next) undergo large revisions when they are recalculated as future time series values become available. Frequent, substantial revisions cause data-users to lose confidence in the usefulness of adjusted data. Indeed, such instabilities in the adjustments should cause the producers of adjustments to question their meaning. Unstable adjustments can be the unavoidable result of the presence of highly variable seasonal or trend movements in the series being adjusted. X-12-ARIMA includes two types of stability diagnostics, sliding spans and revision histories. The sliding spans diagnostics display, and provide summary statistics for, the different outcomes obtained by running the program up to four overlapping subspans of the series. For each month that is common to at least two of the subspans, these diagnostics analyze the difference between the largest and smallest adjustments of the month’s datum obtained from the different spans. They also analyze the largest and smallest estimates of month-to-month changes and of other statistics of interest. They improve upon, or complement in important ways, earlier diagnostics for (i) determining if a series is being adjusted adequately, (ii) for deciding between direct and indirect adjustments of an aggregate series, and (iii) for confirming option choices such as the length chosen for the seasonal filter or showing that other option choices must be tried. The second type of stability diagnostic in X-12-ARIMA considers the revisions associated with continuous seasonal adjustment over a period of years. The basic revision calculated by the program is the difference between the earliest adjustment of a month’s datum obtained when that month is the final month in the series and a later adjustment based on all future data available at the time of the diagnostic analysis. Similar revisions are obtained for month-to-month changes, trend estimates, and trend changes. Sets of these revisions, calculated over a consecutive set of time points within the series, are called revisions histories. 9.4. Forecasting For a given reg ARIMA model with parameters estimated by the X-12-ARIMA programme, the forecast spec will use the model to compute point forecasts, and associated forecast standard errors and prediction intervals. The point forecasts are Minimum Mean Squared Errors (MMSE) linear predictions of future yt ‘s based on the present and past yt ‘s assuming that, i) the regARIMA model form is correct, ii) the correct regression variables have been included, iii) no additive outlier or level shifts will occur in the forecast period, iv) the specifed ARIMA orders are correct, and v) the parameter values used (typically estimated parameters) are equal to the true values. These are standardised assumptions, though obviously unrealistic in practical applications. What is more realistically hoped is that the regARIMA model will be a close enough approximation to the true, unknown model for the results to be approximately valid. Two sets of forecasts errors are produced. One assumes that all parameters are known. The other allows for additional forecast error that comes for estimating the regression parameters, while still assuming that the AR and MA parameters are known. If the series is transformed, the forecasting results are first obtained in the transformed scale, and then transformed back to the original scale. For example, if one specifies a model of form (1) for yt = log( Yt ), where Yt is the original time series, then yt is forecasted first, and the resulting point forecasts and prediction interval limits are exponentiated to produce point and interval forecasts in the original ( Yt ) scale. The resulting point forecasts are MMSE for yt = log(Yt ), but not for Yt , under the standard assumptions mentioned above. If any prior adjustments are made, these will also be inverted in the process of transforming the point forecasts and prediction interval limits back to the original scale. If there are any user-defined regression variables in the model, X-12-ARIMA requires that the user supply data for these variables for the forecast period. For the predefined regression variables in X-12-ARIMA, the programme will generate the future values required. If user-defined prior adjustment factors are specified, values for these should also be supplied for the forecast period. 9.5. Limitations Some of the limitations of X-12-ARIMA procedure are listed below: 1.Observations (data) from a time series to be modeled and / or seasonally adjusted using X-12-ARIMA should be quantitative, as opposed to binary or categorical. 2.Observations must be equally spaced in time, and missing values are not allowed. 3.X-12-ARIMA handles only univariate time series models, i.e., it does not estimate relationships between different time series. 4.The set of automatically identified outliers can change if the regressor set or ARIMA model type is changed. 5.Regressors with t-statistic values just below the critical values can have their t-statistics increase above the critical values as new data are added to the series over time. Conversely, regressors can drop out of the set of identified outliers as new data are added. The printed output of X-12-ARIMA’s automatic-outlier-identification option lists months whose AO or LS regressors are close to the critical values. This is done to enable the user to consider in advance whether to include such regressors in subsequent runs of the program\n\nTop"
] | [
null,
"https://m.rbi.org.in/images/AzadLogo.png",
null,
"https://m.rbi.org.in/Images/pdf.gif",
null,
"https://m.rbi.org.in/scripts/images/78940_ch1.jpg",
null,
"https://m.rbi.org.in/scripts/images/78940_ch2.jpg",
null,
"https://m.rbi.org.in/scripts/images/78940_ch3.jpg",
null,
"https://m.rbi.org.in/scripts/images/78940_ch4.jpg",
null,
"https://m.rbi.org.in/scripts/images/78940_ch5.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9031912,"math_prob":0.85077816,"size":12419,"snap":"2021-31-2021-39","text_gpt3_token_len":2460,"char_repetition_ratio":0.15126863,"word_repetition_ratio":0.005353319,"special_character_ratio":0.18761575,"punctuation_ratio":0.09488715,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9628851,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14],"im_url_duplicate_count":[null,3,null,2,null,2,null,2,null,2,null,2,null,2,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-09-16T21:48:42Z\",\"WARC-Record-ID\":\"<urn:uuid:84148e18-15eb-4ef5-b938-604c5e2286c0>\",\"Content-Length\":\"55636\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:f7043ce8-fd99-432c-bb96-e5172371b055>\",\"WARC-Concurrent-To\":\"<urn:uuid:1d38d033-50f1-4f8b-8af1-bfbaa651d6f9>\",\"WARC-IP-Address\":\"14.140.169.71\",\"WARC-Target-URI\":\"https://m.rbi.org.in/Scripts/PublicationsView.aspx?id=9493\",\"WARC-Payload-Digest\":\"sha1:JCHMZR2FZFXH4BL2VSB4KWXVVS6NCVPV\",\"WARC-Block-Digest\":\"sha1:43HMO233CXHEFFZIYXVNZ733EBFPFZKI\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-39/CC-MAIN-2021-39_segments_1631780053759.24_warc_CC-MAIN-20210916204111-20210916234111-00179.warc.gz\"}"} |
https://fr.scribd.com/document/79102061/Ch2slide | [
"Vous êtes sur la page 1sur 45\n\n# Chapter 2 Principles of Steady-State Converter Analysis\n\n2.1. Introduction 2.2. Inductor volt-second balance, capacitor charge balance, and the small ripple approximation 2.3. Boost converter example 2.4. Cuk converter example 2.5. Estimating the ripple in converters containing twopole low-pass filters 2.6. Summary of key points\nFundamentals of Power Electronics\n1\n\n1\n\nVg\n+\n\n+\n2\n\n+ R v(t)\n\nvs(t)\n\n## Switch output voltage waveform\n\nDuty cycle D: 0D1\n\nvs(t)\n\n## Vg DTs 0 DTs 1 2 D' Ts 0 Ts\n\nt\n1\n\ncomplement D: D = 1 - D\nFundamentals of Power Electronics\n\nswitch position:\n\nvs(t)\n\n## Fourier analysis: Dc component = average value\n\nvs = 1 Ts\nTs\n\nvs(t) dt\n0\n\nvs = 1 (DTsVg) = DVg Ts\nFundamentals of Power Electronics\n3\n\n## Chapter 2: Principles of steady-state converter analysis\n\nInsertion of low-pass filter to remove switching harmonics and pass only dc component\nL + + C R v(t)\n\nVg\n\nvs(t)\n\nv vs = DVg\n\nVg\n\n0 0 1 D\n\na)\n1\n\n1 0.8\n\nM(D) = D\n\nVg\n\nM(D)\n\nBuck\n\niL(t)\nC R\n\n+\n0.6 0.4 0.2\n\nb)\n\nVg\n\nM(D)\n\nBoost\n\niL(t)\n\n4 3 2 1 0 0\n\n1 M(D) = 1 D\n\n0.2\n\n0.4\n\n0.6\n\n0.8\n\nc)\n1 2\n\n0 0\n\n0.2\n\n0.4\n\n0.6\n\n0.8\n\n+ C R v\n\n-1\n\nVg\n\nM(D)\n\nBuck-boost\n\niL(t)\n\n-2 -3 -4 -5\n\nM(D) = 1D D\n\n## Objectives of this chapter\n\nDevelop techniques for easily determining output voltage of an arbitrary converter circuit Derive the principles of inductor volt-second balance and capacitor charge (amp-second) balance Introduce the key small ripple approximation Develop simple methods for selecting filter element values Illustrate via examples\n\nq q\n\n## Chapter 2: Principles of steady-state converter analysis\n\n2.2.\n\nInductor volt-second balance, capacitor charge balance, and the small ripple approximation\nActual output voltage waveform, buck converter\n1\n\niL(t)\n\nVg\n\n## Actual output voltage waveform\n\nv(t) = V + vripple(t)\n\nv(t) V Dc component V 0\n\n## The small ripple approximation\n\nv(t) actual waveform v(t) = V + vripple(t)\n\nv(t) = V + vripple(t)\n\nV Dc component V 0 t\n\nIn a well-designed converter, the output voltage ripple is small. Hence, the waveforms can be easily determined by ignoring the ripple:\nvripple << V\nv(t) V\n\n1\n\niL(t)\n\n## L + vL(t) + iC(t) R v(t)\n\noriginal converter\n\nVg\n\nswitch in position 1\niL(t) L + vL(t) Vg + C + iC(t) R v(t)\n\nswitch in position 2\nL + vL(t) Vg + iL(t) C iC(t) R + v(t)\n\n## Inductor voltage and current Subinterval 1: switch in position 1\n\nInductor voltage\nvL = Vg v(t)\nVg + iL(t) L + vL(t) C iC(t) R + v(t)\n\n## Small ripple approximation:\n\nvL Vg V\n\nKnowing the inductor voltage, we can now find the inductor current via\nvL(t) = L diL(t) dt\n\n10\n\n## Inductor voltage and current Subinterval 2: switch in position 2\n\nInductor voltage\nvL(t) = v(t)\nVg + iL(t) L + vL(t) C + iC(t) R v(t)\n\n## Small ripple approximation:\n\nvL(t) V\n\nKnowing the inductor voltage, we can again find the inductor current via\nvL(t) = L diL(t) dt\n\n## Solve for the slope:\n\ndiL(t) V L dt\nThe inductor current changes with an essentially constant slope\n\n11\n\n## Inductor voltage and current waveforms\n\nvL(t)\nVg V DTs D'Ts V switch position: 1\niL(DTs) Vg V L DTs\n12\n\nt\n1\nvL(t) = L diL(t) dt\n\niL(t)\nI iL(0) 0\n\niL V L Ts\n\n## Determination of inductor current ripple magnitude\n\niL(t)\nI iL(0) 0 Vg V L\n\niL(DTs) V L DTs Ts\n\niL\n\n## (change in iL) = (slope)(length of subinterval) Vg V DTs 2iL = L\n\nV V iL = g DTs 2L\n\nL=\n\nVg V DTs 2iL\n\n13\n\niL(t)\n\niL(Ts) iL(0)=0\n\niL(nTs)\n\niL((n+1)Ts)\n\nnTs\n\n(n+1)Ts\n\n## When the converter operates in equilibrium:\n\niL((n + 1)Ts) = iL(nTs)\n\n14\n\n## The principle of inductor volt-second balance: Derivation\n\nInductor defining relation: di (t) vL(t) = L L dt Integrate over one complete switching period:\n\niL(Ts) iL(0) = 1 L\nTs\n\nTs\n\nvL(t) dt\n0\n\n## In periodic steady state, the net change in inductor current is zero:\n\n0=\n0\n\nvL(t) dt\n\nHence, the total area (or volt-seconds) under the inductor voltage waveform is zero whenever the converter operates in steady state. An equivalent form:\n1 s v (t) dt = v 0= L Ts 0 L The average inductor voltage is zero in steady state.\nFundamentals of Power Electronics\n15\nT\n\n## Inductor volt-second balance: Buck converter example\n\nvL(t) total area t V\n\nVg V\n\nDTs\n\n=\n0\n\nTs\n\n## Average voltage is vL = = D(Vg V) + D'( V) Ts Equate to zero and solve for V:\n\n0 = DVg (D + D')V = DVg V\nFundamentals of Power Electronics\n16\n\nV = DVg\n\n## The principle of capacitor charge balance: Derivation\n\nCapacitor defining relation: dv (t) iC(t) = C C dt Integrate over one complete switching period:\n\nvC(Ts) vC(0) = 1 C\n\nTs\n\niC(t) dt\n0\n\n## In periodic steady state, the net change in capacitor voltage is zero:\n\n0= 1 Ts\n\nTs\n\niC(t) dt = iC\n0\n\nHence, the total area (or charge) under the capacitor current waveform is zero whenever the converter operates in steady state. The average capacitor current is then zero.\n\n17\n\nL\n2\n\n## Boost converter with ideal switch\n\niL(t) Vg +\n\n+ vL(t)\n1\n\niC(t) C R v\n\nD1 + Q1 iC(t) C R v\n\niL(t) Vg +\n\n+ vL(t) +\n\nDTs\n\nTs\n\n18\n\n## Boost converter analysis\n\nL iL(t) + vL(t)\n1 2\n\n+ iC(t) C R v\n\noriginal converter\n\nVg\n\nswitch in position 1\n\nswitch in position 2\nL\n+\n\niL(t) Vg +\n\n+ vL(t)\n\n+ iC(t) C R v\n\n19\n\n## Inductor voltage and capacitor current\n\nvL = Vg iC = v / R\nVg + L iL(t) + vL(t) iC(t) C R + v\n\n## Small ripple approximation:\n\nvL = Vg iC = V / R\n\n20\n\n## Inductor voltage and capacitor current\n\nvL = Vg v iC = iL v / R\nVg + L iL(t) + vL(t) + iC(t) C R v\n\n## Small ripple approximation:\n\nvL = Vg V iC = I V / R\n\n21\n\nvL(t)\n\nVg DTs D'Ts\n\nt\nVg V\n\niC(t)\nDTs V/R\n\nI V/R D'Ts\n\n22\n\n## Inductor volt-second balance\n\nNet volt-seconds applied to inductor over one switching period:\nTs\n\nvL(t)\n\nVg DTs D'Ts\n\n0\n\nt\nVg V\n\n## Equate to zero and collect terms:\n\nVg (D + D') V D' = 0\nSolve for V:\n\n## Vg D' The voltage conversion ratio is therefore V =\n\nM(D) = V = 1 = 1 Vg D' 1 D\nFundamentals of Power Electronics\n23\n\n## Conversion ratio M(D) of the boost converter\n\n5 4\n\n1 1 M(D) = D' = 1 D\n\nM(D)\n\n24\n\nTs 0\n\niC(t)\nDTs\n\nI V/R D'Ts\n\n## iC(t) dt = ( V ) DTs + (I V ) D'Ts R R\n\nt\nV/R\n\nCollect terms and equate to zero: V (D + D') + I D' = 0 R Solve for I: I= V D' R Eliminate V to express in terms of Vg: Vg I= 2 D' R\nFundamentals of Power Electronics\n\nI (V g / R)\n8 6 4 2 0 0 0.2 0.4 0.6 0.8 1\n\n25\n\n## Determination of inductor current ripple\n\nInductor current slope during subinterval 1: diL(t) vL(t) Vg = = L L dt Inductor current slope during subinterval 2: diL(t) vL(t) Vg V = = L L dt\n\niL(t)\nI Vg L 0 DTs Vg V L Ts iL\n\nChange in inductor current during subinterval 1 is (slope) (length of subinterval): Vg 2iL = DTs L Solve for peak ripple:\n\niL =\n\nVg DTs 2L\n\n26\n\n## Determination of capacitor voltage ripple\n\nCapacitor voltage slope during subinterval 1: dvC(t) iC(t) V = = C RC dt Capacitor voltage slope during subinterval 2: dvC(t) iC(t) I = = V C C RC dt\n\nv(t)\nV V RC 0 DTs I V C RC Ts v\n\n## Change in capacitor voltage during subinterval 1 is (slope) (length of subinterval):\n\n2v = V DTs RC\nSolve for peak ripple:\n\nv = V DTs 2RC\nFundamentals of Power Electronics\n\nChoose C such that desired voltage ripple magnitude is obtained In practice, capacitor equivalent series resistance (esr) leads to increased voltage ripple\n27\n\nL1 C1 + v1\n1 2\n\nL2 i2 C2 + v2 R\n\nVg +\n\ni1\n\nL1 i1 Vg +\n\nC1 + v1 Q1 D1\n\nL2 i2 C2 + v2 R\n\n28\n\n## Cuk converter circuit\n\nwith switch in positions 1 and 2\n\n## Switch in position 1: MOSFET conducts Capacitor C1 releases energy to output\n\nVg +\n\nL1 i1 + vL1 v1 +\n\nL2 iC1 + vL2 C1\n\ni2 + iC2 C2 v2 R\n\ni1\n\nL1 + vL1 iC1 + C1 v1\n\nL2 + vL2\n\ni2 iC2 C2 v2 R +\n\nVg +\n\n29\n\n## Waveforms during subinterval 1\n\nMOSFET conduction interval\nInductor voltages and capacitor currents:\nL1 i1 + vL1 Vg + v1 + L2 iC1 + vL2 C1 i2 iC2 C2 + v2 R\n\nvL1 = Vg vL2 = v1 v2 i C1 = i 2 v i C2 = i 2 2 R\n\n## Small ripple approximation for subinterval 1:\n\nvL1 = Vg vL2 = V1 V2 i C1 = I 2 V i C2 = I 2 2 R\n\n30\n\n## Waveforms during subinterval 2\n\nDiode conduction interval\nInductor voltages and capacitor currents:\ni1 L1 + vL1 Vg + C1 iC1 + v1 L2 + vL2 i2 iC2 C2 + v2 R\n\nvL1 = Vg v1 vL2 = v2 i C1 = i 1 v i C2 = i 2 2 R\n\n## Small ripple approximation for subinterval 2:\n\nvL1 = Vg V1 vL2 = V2 i C1 = I 1 V i C2 = I 2 2 R\n\n31\n\n## Equate average values to zero\n\nThe principles of inductor volt-second and capacitor charge balance state that the average values of the periodic inductor voltage and capacitor current waveforms are zero, when the converter operates in steady state. Hence, to determine the steady-state conditions in the converter, let us sketch the inductor voltage and capacitor current waveforms, and equate their average values to zero.\n\nWaveforms:\nInductor voltage vL1(t)\nvL1(t)\n\n## Volt-second balance on L1:\n\nVg DTs D'Ts t Vg V1\n\n32\n\n## Equate average values to zero\n\nInductor L2 voltage\nvL2(t) DTs V1 V2 V2 D'Ts t\n\n## Average the waveforms:\n\nCapacitor C1 current\niC1(t) DTs I2 I1 D'Ts t\n\n33\n\n## Equate average values to zero\n\nCapacitor current iC2(t) waveform\niC2(t) I2 V2 / R (= 0) DTs D'Ts t\n\ni C2 = I 2\n\nV2 =0 R\n\nNote: during both subintervals, the capacitor current iC2 is equal to the difference between the inductor current i2 and the load current V2/R. When ripple is neglected, iC2 is constant and equal to zero.\n\n34\n\n## Cuk converter conversion ratio M = V/Vg\n\nD\n0 0 -1 0.2 0.4 0.6 0.8 1\n\nM(D)\n\n-2 -3 -4 -5\n\nV2 M(D) = = D Vg 1D\n\n35\n\n## Inductor current waveforms\n\nInterval 1 slopes, using small ripple approximation:\ni1(t) I1 i1\nVg L1 Vg V1 L1\n\n## di 1(t) vL1(t) Vg = = L1 L1 dt di 2(t) vL2(t) V1 V2 = = L2 L2 dt\n\nInterval 2 slopes:\ndi 1(t) vL1(t) Vg V1 = = L1 L1 dt di 2(t) vL2(t) V2 = = L2 L2 dt\nI2 i2(t)\n\nDTs\nDTs\nV1 V2 L2 V2 L2\n\nTs\nTs t\n\ni2\n\n36\n\n## Chapter 2: Principles of steady-state converter analysis\n\nCapacitor C1 waveform\nSubinterval 1:\nv1(t) V1 v1\nI2 C1 I1 C1\n\ndv1(t) i C1(t) I 2 = = C1 C1 dt\nSubinterval 2:\n\nDTs\n\nTs\n\ndv1(t) i C1(t) I 1 = = C1 C1 dt\n\n37\n\n## Chapter 2: Principles of steady-state converter analysis\n\nRipple magnitudes\n\nAnalysis results\n\n## Use dc converter solution to simplify:\n\nVgDTs i 1 = 2L 1 V + V2 i 2 = 1 DTs 2L 2 I DT v1 = 2 s 2C 1\n\n38\n\n## 2.5 Estimating ripple in converters containing two-pole low-pass filters\n\nBuck converter example: Determine output voltage ripple\n1\n\nVg\n\n## Inductor current waveform. What is the capacitor current?\n\niL(t)\nI iL(0) 0 Vg V L\n\niL(DTs) V L DTs Ts\n\niL\n\n39\n\niC(t)\n\n## Must not neglect inductor current ripple!\n\nIf the capacitor voltage ripple is small, then essentially all of the ac component of inductor current flows through the capacitor.\nFundamentals of Power Electronics\n\nvC(t) V v v\n\n40\n\n## Estimating capacitor voltage ripple v\n\nCurrent iC(t) is positive for half of the switching period. This positive current causes the capacitor voltage vC(t) to increase between its minimum and maximum extrema. During this time, the total charge q is deposited on the capacitor plates, where\nq = C (2v)\n\nvC(t) V v v\n\n41\n\n## Estimating capacitor voltage ripple v\n\nThe total charge q is the area of the triangle, as shown:\niL Ts / 2 DTs D'Ts t\n\nq = 1 iL 2\n\nTs 2\n\nv =\nvC(t) V v v\n\niL Ts 8C\n\n42\n\n## Inductor current ripple in two-pole filters\n\nExample: problem 2.9\nVg\n+ L1\n\niT\n+ C1 vC1\n\nQ1\n\nL2\n\ni1\n\ni2\nD1 C2 R\n\n+ v\n\nvL(t)\n\n## can use similar arguments, with = L i = inductor flux linkages\n\ni\n\niL(t) I i\n\n= inductor volt-seconds\n\n43\n\n## 2.6 Summary of Key Points\n\n1. The dc component of a converter waveform is given by its average value, or the integral over one switching period, divided by the switching period. Solution of a dc-dc converter to find its dc, or steadystate, voltages and currents therefore involves averaging the waveforms. 2. The linear ripple approximation greatly simplifies the analysis. In a welldesigned converter, the switching ripples in the inductor currents and capacitor voltages are small compared to the respective dc components, and can be neglected. 3. The principle of inductor volt-second balance allows determination of the dc voltage components in any switching converter. In steady-state, the average voltage applied to an inductor must be zero.\n\n44\n\n## Chapter 2: Principles of steady-state converter analysis\n\nSummary of Chapter 2\n4. The principle of capacitor charge balance allows determination of the dc components of the inductor currents in a switching converter. In steadystate, the average current applied to a capacitor must be zero. 5. By knowledge of the slopes of the inductor current and capacitor voltage waveforms, the ac switching ripple magnitudes may be computed. Inductance and capacitance values can then be chosen to obtain desired ripple magnitudes. 6. In converters containing multiple-pole filters, continuous (nonpulsating) voltages and currents are applied to one or more of the inductors or capacitors. Computation of the ac switching ripple in these elements can be done using capacitor charge and/or inductor flux-linkage arguments, without use of the small-ripple approximation. 7. Converters capable of increasing (boost), decreasing (buck), and inverting the voltage polarity (buck-boost and Cuk) have been described. Converter circuits are explored more fully in a later chapter.\nFundamentals of Power Electronics\n45"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6016168,"math_prob":0.9970058,"size":5549,"snap":"2020-10-2020-16","text_gpt3_token_len":2135,"char_repetition_ratio":0.124977455,"word_repetition_ratio":0.08836395,"special_character_ratio":0.33861956,"punctuation_ratio":0.067556955,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9972239,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-04-01T06:16:00Z\",\"WARC-Record-ID\":\"<urn:uuid:a4ad07b7-ea02-429d-8103-97e923627ffd>\",\"Content-Length\":\"368288\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:9a46ac5e-8fe6-4242-b31b-3bfede88f49a>\",\"WARC-Concurrent-To\":\"<urn:uuid:d6a4da3f-6cd1-4dc6-a2ed-f63bbf0da357>\",\"WARC-IP-Address\":\"151.101.250.152\",\"WARC-Target-URI\":\"https://fr.scribd.com/document/79102061/Ch2slide\",\"WARC-Payload-Digest\":\"sha1:ZOWCYTEHPKYXSQDTZQ3632HMCRD3HX3Z\",\"WARC-Block-Digest\":\"sha1:O2PARJTZ3SABT5HSWUCBF7S76KZIHHXL\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-16/CC-MAIN-2020-16_segments_1585370505366.8_warc_CC-MAIN-20200401034127-20200401064127-00454.warc.gz\"}"} |
https://physics.stackexchange.com/questions/310806/viscosity-of-ideal-gas-from-dimensional-analysis | [
"# Viscosity of ideal gas from dimensional analysis\n\nSummary\n\nFrom dimensional analysis I find that the dynamic viscosity of an ideal gas must depend on its pressure $p$, density $\\rho$ and mean molecular free path $l$ in this way:\n\n$$\\mu = C \\sqrt{\\rho p} l.\\quad$$\n\nHere, $C\\geq0$ is a non-dimensional constant.\n\nHowever, I find it counter intuitive that the dynamic viscosity, the 'internal friction', of the fluid increases with an increasing mean free path. My intuition tells me that the internal friction is low if the molecules are widely separated.\n\n• Have I missed some quantity that should enter the expression?\n• Has my derivation failed in some other way?\n• Is my intuitive picture wrong?\n\nThe derivation\n\nIn an ideal gas, molecules are interacting only through ellastic collisions. The equation of state is:\n\n$$p = \\rho R T. \\quad (1)$$\n\nThe variables and their units are:\n\n• $p$: Pressure [kg/(m s$^2$)]\n• $\\rho$: Density [kg/(m$^3$)]\n• $R$: Specific gas constant [m$^2$/(s$^2$ K)]\n• $T$: Temperature [K]\n\nIn general, these are field variables, so $p = p(\\mathbf{x},t)$, $\\rho = \\rho(\\mathbf{x},t)$ and $T = T(\\mathbf{x},t)$. In fluid dynamics, a common assumption is that each infinitesimally small volume is in thermodynamic equilibrium, so that (1) holds at every point in the fluid. I make this assumption. I also assume that the fluid is 'Newtonian', so that the viscous stress tensor is proportional to the rate of strain. The constant of proportionality is the dynamic viscosity, $\\mu$, whose unit is [kg/(m s)].\n\nThe dynamic viscosity is a 'material property'; it is independent of the motion of the fluid. In general, it is varying over space, so that $\\mu = \\mu(\\mathbf{x},t)$. It's value is a property of the material and depends on its thermodynamic state.\n\nIt seems impossible to find how $\\mu$ depends on the thermodynamic state from (1). Pressure has 'almost' the correct units, but I need to multiply the pressure by some time scale $\\tau$ [s]. This time scale must depend on the microscopic properties of the material, and the only way I find it possible to construct it is by using the $l$ [m] the mean free path of the molecules in the fluid. The time scale contructed is:\n\n$$\\tau = \\sqrt{\\frac{\\rho}{p}} l.\\quad (2)$$\n\nUsing (2) I find that the dynamic viscosity must depend on $p$, $\\rho$ and $l$ in this way:\n\n$$\\mu = C \\sqrt{\\rho p} l,\\quad (3)$$\n\nwhere $C\\geq0$ is a non-dimensional constant.\n\n• Actually, the viscosity of an ideal gas (i.e., a real gas in the limit of low pressures) does not depend on p. See Bird, Stewart, and Lightfoot, Transport Phenomena for the derivation you are seeking. Feb 9 '17 at 12:39\n• Is that really true? In such case, for a fixed $R$, I am quite sure that I need a quantity additional to $\\rho$, $p$, $T$, and $l$ to construct the viscosity. I can not think of any such quantity. Which one would that be? Feb 9 '17 at 12:53\n• See my answer below. Feb 9 '17 at 13:08\n\nYour intuition is wrong on this. Consider one-dimensional steady flow, say in the $x$-direction, with a velocity gradient in the $y$-direction. Thus the particles at a given level have average velocity $$\\bar{\\mathbf u}=(u(y), 0, 0)^T,$$ and fluctuating velocities $${\\mathbf u}'=(u', v', w')^T.$$\n\nLet's consider particles that at time $t_0$ are located at $(x,y_0)^T$, which have velocities ${\\mathbf u}=(u_0+u', v', w')^T.$ These particles will, on average, travel a distance of the mean free path length $l$ at that velocity, before hitting other particles. The particles will thus have migrated to a different $y$ position, where the average particle velocity will be $$\\bar{\\mathbf u(y)}=(u(y_0)+(y-y_0)\\frac{\\partial u}{\\partial y}, 0, 0)^T.$$ Notice that the average difference in the $x$-component of the velocity of such particles will therefore be proportional to the mean free path $l$ times an integral $I$ over the distribution of $v'$ and $w'$ velocities which does not matter here: We have $y-y_0=I\\,l$. The mean velocity difference for such particles is therefore just $\\bar{\\Delta u}=I\\,l\\,(\\partial u/\\partial y)$.\n\nSince the mean velocity is assumed to stay constant, such particles will have their velocity adjusted to the one at their new $y$-position. Viscous forces correspond to the work required to achieve this. These forces must therefore be proportional to the velocity gradient times the mean free path length.\n\nP.S.: Also see the derivation in the Wikipedia article on viscosity.\n\n• Thank you for a very good argument for why the visosity increases with $l$. This has developed my intuitive picture of viscosity. Do you agree to this picture of your argument: \"If the mean free path is long, the fluid is more 'entangled'. If momentum exchange between different fluid parts are illustrated by springs, this will to some extent resemble a web of springs that are pushing/pulling the other over some distance. Making each spring longer (increasing the mean free path) makes different parts of the fluid more 'connected' (actually more viscous).\" Feb 9 '17 at 17:25\n• Yes, the notion of \"increased entanglement\" seems to be a meaningful intuitive metaphor for what is happening. The increased \"entanglement\" means there will be higher resistance towards shearing deformation.\n– Pirx\nFeb 9 '17 at 17:27\n\nAccording to Bird, Stewart, and Lightfoot, Transport Phenomena, Chapter 1, Maxwell(1860) obtained the following expression for the viscosity of an ideal gas comprised of rigid spheres: $$\\mu=\\frac{2}{3\\pi}\\frac{\\sqrt{\\pi mkT}}{\\pi d^2}$$where m is the mass of each sphere and d is its diameter. The derivation is presented in the book. Note that this expression is indeed independent of pressure. They also present a graph of reduced viscosity as a function of reduced temperature and reduced pressure.\n\n• What is $k$? Boltzmann's constant? Feb 9 '17 at 13:34\n• If that is the case, then my expression is consistent with this. Consider that the mass $m$ of each sphere equals the density $\\rho$ divided by the number density $\\eta$: $$m = \\frac{\\rho}{\\eta}. \\quad (1)$$ The equation of state is: $$p = \\eta k T. \\quad (2)$$ (1) and (2) gives that: $$m k T = \\frac{p \\rho}{\\eta^2}.$$ Thus: $$\\frac{\\sqrt{m k T}}{d^2} = \\frac{\\sqrt{p \\rho}}{\\eta d^2}.$$ $\\eta d^2$ should be proportional to the inverse of the mean free path (inverse of cross section area times number density), so: $$\\mu \\propto \\sqrt{\\rho p}l.$$ Feb 9 '17 at 14:19\n• But you have an important point in that, for the rigid sphere case and if the derivation in Transport Phenomena is correct, the viscosity for a given molecular composition depends only on the temperature. The reson that $\\rho$ and $p$ enters my equation must be that they in turn depend on $m$ and $d$. Feb 9 '17 at 14:25\n• Check out the derivation in Transport Phenomena. This is a book that has stood the test of time. It has been in use for almost 70 years now, with an updated version coming out in around 2002. I have used this book throughout my long career more than all the other books combined. Feb 9 '17 at 14:50"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8650423,"math_prob":0.99774694,"size":2369,"snap":"2021-43-2021-49","text_gpt3_token_len":620,"char_repetition_ratio":0.109513745,"word_repetition_ratio":0.045,"special_character_ratio":0.27859858,"punctuation_ratio":0.11940298,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9998797,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-12-08T22:22:52Z\",\"WARC-Record-ID\":\"<urn:uuid:f4e4e3f4-8b7b-422a-9ed5-8dcf7826fd7b>\",\"Content-Length\":\"158828\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:28caa95d-a9d9-4c8d-89e2-ffc9908872e5>\",\"WARC-Concurrent-To\":\"<urn:uuid:1bdc8946-357b-4340-9307-c4300c9ea8bd>\",\"WARC-IP-Address\":\"151.101.129.69\",\"WARC-Target-URI\":\"https://physics.stackexchange.com/questions/310806/viscosity-of-ideal-gas-from-dimensional-analysis\",\"WARC-Payload-Digest\":\"sha1:NNLPWZXCESDICBHIFTVK75DNZKJ6I6RG\",\"WARC-Block-Digest\":\"sha1:GVNJ3JJ5NDMB7XL3AFURHRXKNGSVQKAG\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-49/CC-MAIN-2021-49_segments_1637964363598.57_warc_CC-MAIN-20211208205849-20211208235849-00408.warc.gz\"}"} |
https://www.mathlearnit.com/metric-and-imperial-units.html | [
"Metric and Imperial Units, Length\n\nMetric and Imperial units can both be used to measure length.\n\nImperial measurements of length are still commonly used in the US, but metric units are generally more common in other parts of the world.\n\nImperial Units, Length\n\nThe most common Imperial units of length used are:\n\nINCHES , FEET , YARDS , MILES\n\nINCHES\n\nInches are the smallest of the units.\n\nMost basic rulers have inches marked on them.\n\nA US quarter coin is just under an inch in length from side to side across the center.",
null,
"FEET\n\nAfter inches come feet (ft).\n\nOne foot is exactly 12 inches in length.\n\nThe average dinner plate is usually around 1 foot in size from side to side.",
null,
"It's often the case that the height of human beings is measured in feet and inches combined.\n\nFor example the height 6 foot 2, means a height of 6 feet and 2 inches, which is roughly 74 inches altogether.\n\nYARDS\n\nYards are longer than feet, 1 yard is 3 feet in length.\n\nA place where the use of yards occurs a lot is in the game of golf. With many golf courses measured in yards.",
null,
"MILES\n\nA mile is a far longer distance than the other 3 units already mentioned.\n\n1 Mile = 5'280 Feet , 1 Mile = 1'760 Yards\n\nRoad signs between cities are places where distance can be given in miles.\n\nMetric Units, Length\n\nMetric units of length aren't too dissimilar to Imperial units.\n\nThe metric units are:\n\nMILLIMETERS , CENTIMETERS , METERS , KILOMETERS\n\nMILLIMETERS\n\nA millimeter, mm for short. is a very small unit of length, that is usually marked on a standard ruler.\n\nIf you piled 10 sheets of paper on top of each other, they would be roughly 1 millimeter high.\n\nCENTIMETERS\n\nTen millimeters make 1 centimeter (cm). 10mm = 1cm\n\nMETERS\n\nAfter centimeters are meters (m). One meter is 100 centimeters, also 1'000 millimeters.\n\n1m = 100cm = 1'000mm\n\nMany baseball bats are around 1 meter in length.\n\nKILOMETERS\n\n1'000 meters make a kilometer (Km).\n\nKilometers are a common alternative to miles. Such as representing distances on many of the road signs in Europe.\n\nMetric and Imperial Units, Length Conversions\n\nBelow are some handy conversions between metric and imperial units for length.\n\n1 Inch = 2.54mm = 2.54cm , 1 Foot = 0.3048m\n\n1 Yard = 0.9144m , 1 Mile = 1.6093Km\n\n---------------------------\n\n1mm = 0.0394 Inch , 1cm = 0.3937 Inch\n\n1m = 3.2008 ft = 1.0936 Yards\n\n1Km = 0.6214 Miles\n\nAdding and Subtracting Length\n\nAdding and subtracting involving units of length, is done the same way as with normal numbers.\n\nBut it helps to label the correct column with the appropriate units.\n\n(1.1)\n\n12m and 45cm + 5m and 22cm\n\nSolution\n\nThe m and cm can be put above the right columns.\n\nm cm\n1 2 4 5\n+ 5 2 2\n\n1 7 6 7\n\n12m and 45cm + 5m and 22cm = 17m and 67cm\n\n(1.2)\n\n21m and 34cm + 16m and 82cm\n\nSolution\n\nm cm\n2 1 8 2\n+ 1 6 3 4\n\n3 8 1 6\n1\n\n21m and 34cm + 16m and 82cm = 38m and 16cm\n\n(1.3)\n\n45m and 3cm + 7m and 66cm\n\nSolution\n\nm cm\n4 5 0 3\n+ 7 6 6\n\n5 2 6 9\n1\n\n21m and 34cm + 16m and 82cm = 52m and 69cm\n\n(1.4)\n\n5cm and 42mm + 12cm and 84mm\n\nSolution\n\ncm mm\n5 4 2\n+ 1 2 8 4\n\n1 8 2 6\n1\n\n5cm and 42mm + 12cm and 84mm = 18cm and 26mm\n\nSubtraction Examples\n\n(2.1)\n\n64m and 45cm 12m and 23cm\n\nSolution\n\nm cm\n6 4 4 5\n- 1 2 2 3\n\n5 2 2 2\n\n64m and 45cm 12m and 23cm = 52m and 22cm\n\n(2.2)\n\n36m and 71cm 28m and 43cm\n\nSolution\n\nm cm\n2 6\n3 16 7 11\n- 2 8 4 3\n\n0 8 2 8\n\n36m and 71cm 28m and 43cm = 8m and 28cm\n\n(2.3)\n\n58cm and 33mm 42cm and 56mm\n\nSolution\n\ncm mm\n7 2\n5 8 13 13\n- 4 2 5 6\n\n1 5 7 7\n\n58cm and 33mm 42cm and 56mm = 15cm and 77mm\n\n› › Metric and Imperial Units, Length"
] | [
null,
"https://www.mathlearnit.com/images/quarter-coin.png",
null,
"https://www.mathlearnit.com/images/dinner-plate.png",
null,
"https://www.mathlearnit.com/images/golf-course.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.67394865,"math_prob":0.98717105,"size":3959,"snap":"2019-43-2019-47","text_gpt3_token_len":1467,"char_repetition_ratio":0.14816688,"word_repetition_ratio":0.06310014,"special_character_ratio":0.3412478,"punctuation_ratio":0.09517601,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9747982,"pos_list":[0,1,2,3,4,5,6],"im_url_duplicate_count":[null,1,null,1,null,1,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-10-20T14:26:15Z\",\"WARC-Record-ID\":\"<urn:uuid:297161fe-5920-4c23-920e-ab8055b222a7>\",\"Content-Length\":\"26717\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:0ed9a13b-07dd-4989-a332-fe37ba398aaf>\",\"WARC-Concurrent-To\":\"<urn:uuid:a40e0973-2cbb-4845-aa6e-a3ddfca46743>\",\"WARC-IP-Address\":\"173.247.219.150\",\"WARC-Target-URI\":\"https://www.mathlearnit.com/metric-and-imperial-units.html\",\"WARC-Payload-Digest\":\"sha1:BUXIUZVJSD2HRNCCIGKLDUFSTJ4Y5P3A\",\"WARC-Block-Digest\":\"sha1:G4H7NASXN7INS64LILGK3CDDQZJZCZ4S\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-43/CC-MAIN-2019-43_segments_1570986710773.68_warc_CC-MAIN-20191020132840-20191020160340-00229.warc.gz\"}"} |
https://it.mathworks.com/help/fixedpoint/ug/estimate-standard-deviation-of-quantization-noise-of-real-valued-signal.html | [
"# Estimate Standard Deviation of Quantization Noise of Real-Valued Signal\n\nQuantizing a real signal to $p$ bits of precision can be modeled as a linear system that adds normally distributed noise with a standard deviation of ${\\sigma }_{N}=\\frac{{2}^{-p}}{\\sqrt{12}}$ [1,2].\n\nCompute the theoretical quantization noise standard deviation with $p$ bits of precision using the `fixed.realQuantizationNoiseStandardDeviation` function.\n\n```p = 14; theoreticalQuantizationNoiseStandardDeviation = fixed.realQuantizationNoiseStandardDeviation(p);```\n\nThe returned value is ${\\sigma }_{N}=\\frac{{2}^{-p}}{\\sqrt{12}}$.\n\nCreate a real signal with $n$ samples.\n\n```rng('default'); n = 1e6; x = rand(1,n);```\n\nQuantize the signal with $p$ bits of precision.\n\n```wordLength = 16; x_quantized = quantizenumeric(x,1,wordLength,p);```\n\nCompute the quantization noise by taking the difference between the quantized signal and the original signal.\n\n`quantizationNoise = x_quantized - x;`\n\nCompute the measured quantization noise standard deviation.\n\n`measuredQuantizationNoiseStandardDeviation = std(quantizationNoise)`\n```measuredQuantizationNoiseStandardDeviation = 1.7607e-05 ```\n\nCompare the actual quantization noise standard deviation to the theoretical and see that they are close for large values of $n$.\n\n`theoreticalQuantizationNoiseStandardDeviation`\n```theoreticalQuantizationNoiseStandardDeviation = 1.7619e-05 ```\n\n### References\n\n1. Bernard Widrow. “A Study of Rough Amplitude Quantization by Means of Nyquist Sampling Theory”. In: IRE Transactions on Circuit Theory 3.4 (Dec. 1956), pp. 266–276.\n\n2. Bernard Widrow and István Kollár. Quantization Noise – Roundoff Error in Digital Computation, Signal Processing, Control, and Communications. Cambridge, UK: Cambridge University Press, 2008.",
null,
""
] | [
null,
"https://it.mathworks.com/images/responsive/supporting/apps/doc_center/bg-trial-arrow.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.6965141,"math_prob":0.997237,"size":1533,"snap":"2021-43-2021-49","text_gpt3_token_len":351,"char_repetition_ratio":0.22367561,"word_repetition_ratio":0.0,"special_character_ratio":0.19699934,"punctuation_ratio":0.18103448,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9978458,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-12-06T21:09:39Z\",\"WARC-Record-ID\":\"<urn:uuid:290a4420-cb19-41f5-bfde-98f5e4ee5332>\",\"Content-Length\":\"77038\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:a5fc0241-65f9-4477-9177-369952666b34>\",\"WARC-Concurrent-To\":\"<urn:uuid:0be5b20d-e16e-4d8e-8dbe-45419f99ac00>\",\"WARC-IP-Address\":\"104.69.217.80\",\"WARC-Target-URI\":\"https://it.mathworks.com/help/fixedpoint/ug/estimate-standard-deviation-of-quantization-noise-of-real-valued-signal.html\",\"WARC-Payload-Digest\":\"sha1:CRJFCRDXTDB7MCL4432SP347YV2JS57Z\",\"WARC-Block-Digest\":\"sha1:KXREZGXG7IHMVTUTTEHJGTKEFMPO2NMH\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-49/CC-MAIN-2021-49_segments_1637964363312.79_warc_CC-MAIN-20211206194128-20211206224128-00179.warc.gz\"}"} |
http://molecafe.com/chemistry%202%20study%20guides/energy.htm | [
"Name: Online Study Guide - Chem 2 - Energy\n\nMultiple Choice\nIdentify the letter of the choice that best completes the statement or answers the question.\n\n1.\n\nThe kinetic energy of an object increases as its ____ increases.\n a. gravitational energy c. specific heat b. potential energy d. velocity\n\n2.\n\nThe SI unit for energy is the ____.\n a. calorie c. meter per second b. joule d. kilogram\n\n3.\n\nAccording to the law of conservation of energy, the total amount of energy in the universe ____.\n a. remains constant c. increases b. changes constantly d. decreases\n\n4.\n\nIn a chemical change, energy can be _____.\n a. created, but not destroyed c. either created or destroyed b. destroyed, but not created d. neither created nor destroyed\n\n5.\n\nThe two terms below that are identical in meaning are _____.\n a. calorie and Calorie c. Calorie and joule b. calorie and joule d. kilocalorie and Calorie\n\n6.\n\nIf the heat of reaction is negative, the reaction is _____.\n a. endothermic c. negative b. exothermic d. positive\n\n7.\n\nA burger contains 220 nutritional Calories. Convert this energy into joules.\n a. 9.2 ´ 10",
null,
"J c. 2.2 ´ 10",
null,
"J b. 9.2 ´ 10",
null,
"J d. 5.5 ´ 10",
null,
"J\n\n8.\n\nRice contains 245 nutritional Calories. Calculate the energy in joules.\n a.",
null,
"J c.",
null,
"J b.",
null,
"J d.",
null,
"J\n\n9.\n\nWhat is the energy required to raise the temperature of 1 g of a substance by 1ºC or 1 K?\n a. specific heat c. heat capacity b. heat energy d. enthalpy of formation\n\n10.\n\nA 4.0 g sample of iron was heated from 0ºC to 20.ºC. It absorbed 35.2 J of energy as heat. What is the specific heat of this piece of iron?\n a. 2816 J/(g·ºC) c. 2.27 J/g b. 2.27 J/(g·ºC) d. 0.44 J/(g·ºC)\n\n11.\n\nHow much energy does a copper sample absorb as energy in the form of heat if its specific heat is 0.384 J/(g·ºC), its mass is 8.00 g, and it is heated from 10.0ºC to 40.0ºC?\n a. 0.0016 J/(g·ºC) c. 92.2 J b. 0.0016 J d. 92.2 J/(g·ºC)\n\n12.\n\nFind the specific heat of a material if a 6.0 g sample absorbs 50. J when it is heated from 30ºC to 50ºC.\n a. 0.60 J c. 0.42 J b. 0.60 J/(g·ºC) d. 0.42 J/(g·ºC)\n\n13.\n\nHow much energy is absorbed as heat by 20. g of gold when it is heated from 25ºC to 35ºC? The specific heat of gold is 0.13 J/g·ºC.\n a. 26 J c. 0.0006 J b. 26 J/(g·ºC) d. 0.0006 J/(g·ºC)\n\n14.\n\nA 5.0 g sample of silver is heated from 0ºC to 35ºC and absorbs 42 J of energy as heat. What is the specific heat of silver?\n a. 0.24 J c. 0.74 J b. 0.24 J/(g·ºC) d. 0.74 J(g·ºC)\n\n15.\n\nThe Greek letter D stands for\n a. \"heat stored in.\" c. \"rate of.\" b. \"mass of.\" d. \"change in.\"\n\n16.\n\nWhat would likely happen if you were to touch the flask in which an endothermic reaction were occurring?\n a. The flask would probably feel cooler than before the reaction started. b. The flask would probably feel warmer than before the reaction started. c. The flask would feel the same as before the reaction started. d. none of the above\n\n17.\n\nWhen energy is changed from one form to another, ____.\n a. some of the energy is lost entirely b. all of the energy can be accounted for c. a physical change occurs d. all of the energy is changed to a useful form\n\n18.\n\nA process that absorbs heat is a(n) ____.\n a. endothermic process c. exothermic process b. polythermic process d. ectothermic process\n\n19.\n\nHow many joules are in 148 calories? (1 cal = 4.18 J)\n a. 6.61 J c. 148 J b. 35.4 J d. 619 J\n\n20.\n\nThe specific heat of silver is 0.24",
null,
". How many joules of energy are needed to warm 4.37 g of silver from 25.0",
null,
"C to 27.5",
null,
"C?\n a. 2.62 J c. 45.5 J b. 0.14 J d. 0.022 J\n\n21.\n\nCalculate the kinetic energy in J of an electron (mass = 9.11 x 10-28 kg) moving at 6.00 x 106 m/s.\n a. 4.98 x 10-48 d. 2.49 x 10-48 b. 3.28 x 10-14 e. 6.56 x 10-14 c. 1.64 x 10-14\n\n22.\n\nThe kinetic energy of a 7.3 kg steel ball traveling at 18.0 m/s __________ J.\n a. 1.2 x 103 d. 1.3 x 102 b. 66 e. 7.3 c. 2.4 x 103\n\n23.\n\nCalculate the kinetic energy (J) of a 150 lb jogger (68.1 kg) traveling at 12.0 mile/hr (5.36 m/s).\n a. 1.96 x 103 d. 183 b. 365 e. 68.1 c. 978\n\n24.\n\nDetermine the kinetic energy (J) of an 80.0 g bullet traveling at 300.0 m/s.\n a. 3.60 x 106 d. 12.0 b. 1.20 x 104 e. 80.0 c. 3.60 x 103\n\n25.\n\nWork equals force _____ distance.\n a. plus d. divided by b. times e. combined with c. minus\n\n26.\n\nOne Joule equals __________.\n a. 1 kgm2/s2 d. 1 gcm/s b. 2 kg e. none of these c. 4.184 cal\n\n27.\n\nAt what velocity (m/s) must a 20.0 g object be moving in order to possess a kinetic energy of 1.00 J?\n a. 1.00 d. 1.00 x 103 b. 100 x 102 e. 50.0 c. 10.0\n\n28.\n\nHow much kinetic energy (in J) is possessed by a 23.2 g object moving at a speed of 81.9 km/hr?\n a. 1900 d. 1.43 x 10-3 b. 77.8 e. 6.00 c. 145\n\n29.\n\nAt what speed must a 35.0 mg object be moving in order to possess 1.20 J of kinetic energy?\n a. 0.262 km/hr d. 943 km/hr b. 15.7 km/hr e. 26.9 km/hr c. 262 km/hr\n\n30.\n\nThe first law of thermodynamics states that __________.\n a. all spontaneous processes are accompanied by an increase in disorder b. energy is conserved during any process c. the entropy of a pure, crystalline substance at absolute zero is zero d. the amount of work done during a change is independent of the pathway of that change e. none of these\n\n31.\n\nWhat is the DE (in J) of a system that releases 12.4 J of heat and does 4.2 J of work on the surroundings?\n a. 16.6 d. -16.6 b. 12.4 e. -8.2 c. 4.2\n\n32.\n\nThe value of DE for a system that performs 213 kJ of work on its surroundings and loses 79 kJ of heat is __________ kJ.\n a. +292 d. -134 b. -292 e. -213 c. +134\n\n33.\n\nCalculate the value of DE (in J) for a system that loses 50 J of heat and has 150 J of work performed on it by the surroundings.\n a. 50 d. -200 b. 100 e. +200 c. -100\n\n34.\n\nWhich of the following is a statement of the first law of thermodynamics?\n a. Ek = 1/2mv2 b. a negative DH corresponds to an exothermic process c. DE = Efinal - Einitial d. Energy lost by the system must be gained by the surroundings. e. 1 cal = 4.184 J (exactly)\n\n35.\n\nA _____ q corresponds to an _____ process.\n a. negative, endothermic d. zero, exothermic b. negative, exothermic e. zero, endothermic c. positive, exothermic\n\n36.\n\nWhat is the change in the internal energy (in J) of a system that absorbs 2,500 J of heat and that does 7,655 J of work on the surroundings?\n a. 10,155 d. -10,155 b. 5,155 e. 1.91 x 107 c. -5,155\n\n37.\n\nWhat is the change in the internal energy (in J) of a system that releases 2,500 J of heat and that does 7,655 J of work on the surroundings?\n a. -10,155 d. 10,155 b. -5,155 e. 5,155 c. -1.91 x 107\n\n38.\n\nWhen a sample of aluminum absorbed 9.86 J of heat, its temperature increased from 23.2°C to 30.5°C. Since the specific heat of aluminum is 0.90 J/g-K, the mass of the sample was _____ g.\n a. 72 d. 8.1 b. 1.5 e. 6.6 c. 65\n\n39.\n\nWhen 72 g of a metal at 97.0°C is added to 100.0 g of water at 25.0°C, the final temperature is 29.1°C. What is the heat capacity (in J/g-K) of the metal? The specific heat of H2O(l) is 4.18 J/g-K.\n a. 0.46 d. 2.0 b. 2.8 e. 4.18 c. 0.35\n\n40.\n\nCalculate the heat capacity (in J/g-K) for metal X from the following information. A sample of the metal (95 g) at 75.0°C is placed in 50.0 g of water at 18.0°C. The specific heat of H2O(l) is 4.18 J/g-K. The final temperature of the water is 23.0°C.\n a. 23 d. 3.6 b. 0.21 e. 4.2 c. 0.76\n\n41.\n\nThe specific heat of copper metal is 0.38 J/g-K. Assume you had a 75 g cube of copper at 25.0°C. What would the final temperature of the copper be (in °C) if it absorbed 150.0 J of heat?\n a. 19.7 d. 25.8 b. 5.3 e. -5.3 c. 30.3\n\n42.\n\nHow much energy (in kJ) is required to raise the temperature of 500.0 g of water from 20.00°C to 20.15°C?\n a. 2.092 d. 0.3138 b. 331.8 e. 209.2 c. 75.00\n\n43.\n\nIf 73.51 J of heat were added to 25.6 g of water at 25.3°C, what would be the final temperature of the water?\n a. 26.0°C d. 13.8°C b. 39.1°C e. -13.8°C c. 98.8°C\n\n44.\n\nHow many grams of water can be heated from 20.0°C to 25.0°C by the addition of 324 J of energy?\n a. 15.5 d. 6.78 x 103 b. 20.9 e. 387 c. 1.36 x 103\n\nMatching\n\nMatch the terms below with their correct definitions.\n a. system e. kinetic energy b. calorimeter f. potential energy c. thermochemistry g. surroundings d. universe\n\n45.\n\nAn insulated device used to measure the amount of heat absorbed or released during a chemical or physical process\n\n46.\n\nThe study of heat changes that accompany chemical reactions and phase changes\n\n47.\n\nThe specific part of the universe that contains the reaction or process you wish to study\n\n48.\n\nA system plus its surroundings\n\n49.\n\nEverything in the universe except the system being studied\n\n50.\n\nenergy of motion"
] | [
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0080000.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0080001.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0080002.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0080003.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0090000.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0090001.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0090002.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0090003.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0210000.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0210001.jpg",
null,
"http://molecafe.com/chemistry%202%20study%20guides/energy_files/i0210002.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.81298846,"math_prob":0.9738196,"size":8612,"snap":"2019-26-2019-30","text_gpt3_token_len":3210,"char_repetition_ratio":0.12279275,"word_repetition_ratio":0.055924695,"special_character_ratio":0.41372505,"punctuation_ratio":0.20789585,"nsfw_num_words":1,"has_unicode_error":false,"math_prob_llama3":0.99570125,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22],"im_url_duplicate_count":[null,3,null,3,null,3,null,3,null,3,null,3,null,3,null,3,null,3,null,3,null,3,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-06-26T18:04:25Z\",\"WARC-Record-ID\":\"<urn:uuid:4a4bb123-cba5-4874-8cf3-e984ce607d96>\",\"Content-Length\":\"220737\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e1eb11cc-c6ff-4de3-aa09-206f2e8a05bc>\",\"WARC-Concurrent-To\":\"<urn:uuid:545e0a53-8d8c-4dca-a7aa-60e324d72630>\",\"WARC-IP-Address\":\"216.92.164.93\",\"WARC-Target-URI\":\"http://molecafe.com/chemistry%202%20study%20guides/energy.htm\",\"WARC-Payload-Digest\":\"sha1:QRRVGCHIEHG2AS5K2J2F6FM6XGOVOPEF\",\"WARC-Block-Digest\":\"sha1:26MZT7OUKP32M5K464YAJJS44DF332GI\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-26/CC-MAIN-2019-26_segments_1560628000414.26_warc_CC-MAIN-20190626174622-20190626200622-00486.warc.gz\"}"} |
http://popflock.com/learn?s=2_(number) | [
"",
null,
"2 (number)\nGet 2 Number essential facts below. View Videos or join the 2 Number discussion. Add 2 Number to your PopFlock.com topic list for future reference or share this resource on social media.\n2 Number\n\n ← 1 2 3 →\nCardinaltwo\nOrdinal2nd (second / twoth)\nNumeral systembinary\nFactorizationprime\nGaussian integer factorization$(1+i)(1-i)$",
null,
"Prime1st\nDivisors1, 2\nGreek numeral\nRoman numeralII\nRoman numeral (unicode)II, ii\nGreek prefixdi-\nLatin prefixduo- bi-\nOld English prefixtwi-\nBinary102\nTernary23\nQuaternary24\nQuinary25\nSenary26\nOctal28\nDuodecimal212\nVigesimal220\nBase 36236\nGreek numeral?'\nArabic & Kurdish?\nUrdu",
null,
"Ge'ez?\nBengali?\nChinese numeral?,?,?\nDevan?gar??\nTelugu?\nTamil?\nHebrew?\nJapanese numeral?/?\nKhmer?\nKorean?,?\nThai?\n\n2 (two) is a number, numeral, and glyph. It is the natural number following 1 and preceding 3.\n\nIn mathematics\n\nAn integer is called even if it is divisible by 2. For integers written in a numeral system based on an even number, such as decimal, hexadecimal, or in any other base that is even, divisibility by 2 is easily tested by merely looking at the last digit. If it is even, then the whole number is even. In particular, when written in the decimal system, all multiples of 2 will end in 0, 2, 4, 6, or 8.\n\nTwo is the smallest prime number, and the only even prime number (for this reason it is sometimes called \"the oddest prime\"). The next prime is three. Two and three are the only two consecutive prime numbers. 2 is the first Sophie Germain prime, the first factorial prime, the first Lucas prime, and the first Ramanujan prime.\n\nTwo is the third (or fourth) Fibonacci number.\n\nTwo is the base of the binary system, the numeral system with the fewest tokens allowing to denote a natural number n substantially more concise (log2n tokens), compared to a direct representation by the corresponding count of a single token (n tokens). This binary number system is used extensively in computing.\n\nFor any number x:\n\nx + x = 2 · x addition to multiplication\nx · x = x2multiplication to exponentiation\nxx = x2 exponentiation to tetration\n\nExtending this sequence of operations by introducing the notion of hyperoperations, here denoted by \"hyper(a,b,c)\" with a and c being the first and second operand, and b being the level in the above sketched sequence of operations, the following holds in general:\n\nhyper(x,n,x) = hyper(x,(n + 1),2).\n\nTwo has therefore the unique property that , disregarding the level of the hyperoperation, here denoted by Knuth's up-arrow notation. The number of up-arrows refers to the level of the hyperoperation.\n\nTwo is the only number x such that the sum of the reciprocals of the powers of x equals itself. In symbols\n\n$\\sum _{k=0}^{\\infty }{\\frac {1}{2^{k}}}=1+{\\frac {1}{2}}+{\\frac {1}{4}}+{\\frac {1}{8}}+{\\frac {1}{16}}+\\cdots =2.$",
null,
"This comes from the fact that:\n\n$\\sum _{k=0}^{\\infty }{\\frac {1}{n^{k}}}=1+{\\frac {1}{n-1}}\\quad {\\mbox{for all}}\\quad n\\in \\mathbb {R} >1.$",
null,
"Powers of two are central to the concept of Mersenne primes, and important to computer science. Two is the first Mersenne prime exponent.\n\nTaking the square root of a number is such a common mathematical operation, that the spot on the root sign where the exponent would normally be written for cubic and other roots, may simply be left blank for square roots, as it is tacitly understood.\n\nThe square root of 2 was the first known irrational number.\n\nThe smallest field has two elements.\n\nIn a set-theoretical construction of the natural numbers, 2 is identified with the set {{?},?}. This latter set is important in category theory: it is a subobject classifier in the category of sets.\n\nTwo also has the unique property such that\n\n$\\sum _{k=0}^{n-1}2^{k}=2^{n}-1$",
null,
"and also\n\n$\\sum _{k=a}^{n-1}2^{k}=2^{n}-\\sum _{k=0}^{a-1}2^{k}-1$",
null,
"for a not equal to zero\n\nIn any n-dimensional, euclidean space two distinct points determine a line.\n\nFor any polyhedron homeomorphic to a sphere, the Euler characteristic is , where V is the number of vertices, E is the number of edges, and F is the number of faces.\n\nList of basic calculations\n\nMultiplication 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 50 100 1000\n2 × x 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 100 200 2000\nDivision 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15\n2 ÷ x 2 1 0.6 0.5 0.4 0.3 0.285714 0.25 0.2 0.2 0.18 0.16 0.153846 0.142857 0.13\nx ÷ 2 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5\nExponentiation 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20\n2x 2 4 8 16 32 64 128 256 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576\nx2 1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 256 289 324 361 400\n\nEvolution of the glyph\n\nThe glyph used in the modern Western world to represent the number 2 traces its roots back to the Indic Brahmic script, where \"2\" was written as two horizontal lines. The modern Chinese and Japanese languages still use this method. The Gupta script rotated the two lines 45 degrees, making them diagonal. The top line was sometimes also shortened and had its bottom end curve towards the center of the bottom line. In the Nagari script, the top line was written more like a curve connecting to the bottom line. In the Arabic Ghubar writing, the bottom line was completely vertical, and the glyph looked like a dotless closing question mark. Restoring the bottom line to its original horizontal position, but keeping the top line as a curve that connects to the bottom line leads to our modern glyph.\n\nIn fonts with text figures, 2 usually is of x-height, for example,",
null,
".\n\nIn religion\n\nJudaism\n\nThe number 2 is important in Judaism, with one of the earliest references being that God ordered Noah to put two of every unclean animal (Gen. 7:2) in his ark (see Noah's Ark). Later on, the Ten Commandments were given in the form of two tablets. The number also has ceremonial importance, such as the two candles that are traditionally kindled to usher in the Shabbat, recalling the two different ways Shabbat is referred to in the two times the Ten Commandments are recorded in the Torah. These two expressions are known in Hebrew as ? (\"guard\" and \"remember\"), as in \"Guard the Shabbat day to sanctify it\" (Deut. 5:12) and \"Remember the Shabbat day to sanctify it\" (Ex. 20:8). Two challot (lechem mishneh) are placed on the table for each Shabbat meal and a blessing made over them, to commemorate the double portion of manna which fell in the desert every Friday to cover that day's meals and the Shabbat meals.\n\nIn Jewish law, the testimonies of two witnesses are required to verify and validate events, such as marriage, divorce, and a crime that warrants capital punishment.\n\n\"Second-Day Yom Tov\" (Yom Tov Sheini Shebegaliyot) is a rabbinical enactment that mandates a two-day celebration for each of the one-day Jewish festivals (i.e., the first and seventh day of Passover, the day of Shavuot, the first day of Sukkot, and the day of Shemini Atzeret) outside the Land of Israel.\n\nNumerological significance\n\nThe most common philosophical dichotomy is perhaps the one of good and evil, but there are many others. See dualism for an overview. In Hegelian dialectic, the process of synthesis reconciles two different perspectives into one.\n\nThe ancient Sanskrit language of India, does not only have a singular and plural form for nouns, as do many other languages, but instead has, a singular (1) form, a dual (2) form, and a plural (everything above 2) form, for all nouns, due to the significance of 2. It is viewed as important because of the anatomical significance of 2 (2 hands, 2 nostrils, 2 eyes, 2 legs, etc.)\n\nTwo (?, èr) is a good number in Chinese culture. There is a Chinese saying, \"good things come in pairs\". It is common to use double symbols in product brand names, e.g. double happiness, double coin, double elephants etc. Cantonese people like the number two because it sounds the same as the word \"easy\" (?) in Cantonese.\n\nIn Finland, two candles are lit on Independence Day and put on a windowsill, to remind passersby of the sacrifices of past generations in the struggle for independence and democracy.\n\nIn pre-1972 Indonesian and Malay orthography, 2 was shorthand for the reduplication that forms plurals: orang \"person\", orang-orang or orang2 \"people\".[]\n\nIn Astrology, Taurus is the second sign of the Zodiac.\n\nIn sports\n\n• In baseball scorekeeping, 2 is the position of the catcher.\n• A standard basket, known in the rules as a \"field goal\", is worth 2 points.\n• In the 3x3 variant, successful shots from behind the \"three-point\" arc are instead worth 2 points (all other successful shots are worth 1 point).\n• In play diagrams, \"2\" typically denotes the shooting guard.\n• In ice hockey:\n• A team typically has two defencemen on the ice at any given time.\n• Minor penalties last for 2 minutes or until the non-penalized team scores a goal, whichever comes first.\n• In most rugby league competitions (though not the Super League, which uses static squad numbering), the starting right wing wears number 2.\n• In rugby union and its sevens variant, the starting hooker wears number 2.\n• In association football, a player scoring two goals in one match is said to have recorded a brace."
] | [
null,
"http://popflock.com/images/logo/popflock-logo.gif",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/539837b4c1731ea8daee381ee01b327db943ab87",
null,
"http://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Urdu_numeral_two.svg/7px-Urdu_numeral_two.svg.png",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/d9723c9514c97dd81a04c43dc125c3ac1150b95a",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/e53d356137742f7d2012603436d0834efd928ebe",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/8d5f31ff86f0d58c4687a9d8e8b2b5a327f53f31",
null,
"https://wikimedia.org/api/rest_v1/media/math/render/svg/fafe500eb2bc95887b80b03d5ae4310a930d4548",
null,
"http://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Text_figures_256.svg/60px-Text_figures_256.svg.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8993569,"math_prob":0.96859574,"size":7789,"snap":"2019-43-2019-47","text_gpt3_token_len":2103,"char_repetition_ratio":0.10828517,"word_repetition_ratio":0.035610463,"special_character_ratio":0.30350494,"punctuation_ratio":0.12617114,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9564271,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16],"im_url_duplicate_count":[null,null,null,null,null,2,null,null,null,null,null,null,null,null,null,6,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-10-14T23:02:04Z\",\"WARC-Record-ID\":\"<urn:uuid:0ba1c599-c5a4-4da8-8ed4-0e5f521879cb>\",\"Content-Length\":\"134248\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:af2a6374-5423-4cde-91e6-1895d42bc0c2>\",\"WARC-Concurrent-To\":\"<urn:uuid:8fa6476a-49e3-4de9-b78b-904fc030f31b>\",\"WARC-IP-Address\":\"75.98.175.100\",\"WARC-Target-URI\":\"http://popflock.com/learn?s=2_(number)\",\"WARC-Payload-Digest\":\"sha1:YLTKFTT7BR4CYG7NBISU26WXCGWJZIF7\",\"WARC-Block-Digest\":\"sha1:OMBIVEPATYFRRYLNXXCVEDL44UGILCTM\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-43/CC-MAIN-2019-43_segments_1570986655554.2_warc_CC-MAIN-20191014223147-20191015010647-00069.warc.gz\"}"} |
https://www.aivc.org/resource/high-accuracy-heat-flow-calculation-method-calculate-heat-flow-arbitrary-wall-constant | [
"",
null,
"Anderlind G\nYear:\n1997\nLanguages: English | Pages: 10 pp\nBibliographic info:\nSweden, Journal of Building Physics, 1997\n\nThe paper describes a method to calculate the heat flow through a multiple layer wall in a natural climate. The thermal properties needed for the calculation are the thermal resistance and the heat capacity of each layer, and they are assumed to be independent of the temperature. The natural climate can be measured temperatures, either surface temperatures or temperatures of the surrounding air. The method is based on well-known equations for calculating the heat flow due to a sinusoidal temperature variation. The natural climate is first transformed to a sum of periodical variations by using Fourier analysis. The heat flow is then obtained as the sum of the heat flows caused by the individual temperature components. In the paper, there is a comparison between the heat flows calculated with an analytical, exact solution and the heat flows calculated with the suggested method for a single layer wall exposed to a sudden external temperature step. The proposed method gives results close to the exact solution. There is also a comparison of the thermal performance of three walls, a light wooden stud wall, a gas concrete wall and a heavy concrete sandwich wall. All three are exposed to a temperature step on the external side and the heat flows on the internal side are calculated. The suggested method to calculate the heat flow through a wall in a natural climate is a good alternative to existing finite difference and finite element methods. The only approximation needed is to describe the boundary temperatures with Fourier series. After this approximation, all remaining calculations are exact."
] | [
null,
"https://www.aivc.org/sites/default/files/default_images/default_image_5.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9051353,"math_prob":0.95858616,"size":1872,"snap":"2021-43-2021-49","text_gpt3_token_len":340,"char_repetition_ratio":0.16916488,"word_repetition_ratio":0.047138046,"special_character_ratio":0.18162394,"punctuation_ratio":0.08510638,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98369557,"pos_list":[0,1,2],"im_url_duplicate_count":[null,9,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-10-22T10:34:56Z\",\"WARC-Record-ID\":\"<urn:uuid:96170d17-7d04-40ac-a4ec-666c0dff6e53>\",\"Content-Length\":\"81965\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:36b08f3a-9bd5-40cb-b576-6596ff6345ce>\",\"WARC-Concurrent-To\":\"<urn:uuid:04a441a1-b172-410e-96e8-e26f99e9739d>\",\"WARC-IP-Address\":\"5.9.12.133\",\"WARC-Target-URI\":\"https://www.aivc.org/resource/high-accuracy-heat-flow-calculation-method-calculate-heat-flow-arbitrary-wall-constant\",\"WARC-Payload-Digest\":\"sha1:KJRRFJBJ5GWG2LMB3WJXYLGIO4TLGJ5D\",\"WARC-Block-Digest\":\"sha1:EZNUEOCWPLZYNI637OXFPWKSFR7256TK\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-43/CC-MAIN-2021-43_segments_1634323585504.90_warc_CC-MAIN-20211022084005-20211022114005-00138.warc.gz\"}"} |
https://cs.stackexchange.com/questions/1274/how-to-score-a-given-arrangement-of-windows-on-a-screen-to-produce-good-layouts | [
"# How to score a given arrangement of windows on a screen to produce good layouts\n\n(this is related to my other question, see here)\n\nI would like to write a function that scores a given arrangement of windows on a screen.\n\nThe purpose of this function is to determine whether a particular layout is good and by going over other possible layouts, finding the one with the highest score.\n\nHere are some characteristics that I think make a good layout:\n\n1. maximizing amount of space used by windows (or in other words, the free space on the screen should be minimized)\n2. windows are (more or less) evenly sized\n\nBonus: assigning each window a priority and giving a higher score for layouts where windows with a higher priority take more space.\n\nHere's an example: Suppose our screen is 11x11 and we want to put two windows on it. Window A's initial size is 1x1 and window B is 2x1.\n\nWhen we resize windows, we preserve their aspect ratio. So here are two possible layout:",
null,
"The function should give the one on the right a higher score.\n\nAnother nice thing to have is the option to 'dock' a window to one or more sides of the screen. Then suppose we want to dock A to the bottom-left of the screen, the scoring function should prefer this layout than the above one on the right:",
null,
"• Nice problem. It sounds like a variation of en.wikipedia.org/wiki/Cutting_stock_problem or en.wikipedia.org/wiki/Bin_packing_problem to me. – Joe Apr 14 '12 at 20:40\n• @daniel.jackson This question doesn't seem very Math-focused if you're looking to write a function. I see that you already got help with designing the algorithm in your previous question, so are you just looking for someone to write the code for you here? You may get a better response by posting to Stack Overflow and including any code you have so far. – Adam Lear Apr 16 '12 at 5:43\n• @AnnaLear: Where in any of my questions here have I asked for code? – daniel.jackson Apr 16 '12 at 9:42\n• @daniel.jackson This question starts with \"I would like to write a function\" and the rest seems to be specifying requirements. From there, I figured you were looking for code. If you're not, can you clarify what you are looking for instead please? Thanks! – Adam Lear Apr 16 '12 at 16:36\n• @AnnaLear: I believe you misunderstood. I asked how to determine if a given layout is a good one according to some variables I thought are related. If it's easier for someone to convey an idea through actual code, great. – daniel.jackson Apr 16 '12 at 17:03\n\nI will expand on my comment on the other question and propose a target function that ensures that no very small windows occur and that windows are not unnecessarily far away from screen edges. Let $\\mathcal{W} = \\{1,\\dots,n\\}$ a set of windows and $T = \\mathcal{W} \\to \\mathbb{N}^4$ a tiling; if $T(W) = (x,y,w,h)$ window $W$'s top-left corner is positioned at $(x,y)$ and $W$ has width $w$ and height $h$. Now let $c : (\\mathbb{N}^4)^\\mathcal{W} \\to \\mathbb{R}$ a cost function from the space of all tilings to the reals:\n$\\qquad \\displaystyle c(T) = \\left[ \\min_{W \\in \\mathcal{W}} T(W)_3\\cdot T(W)_4 \\right] - \\sum\\limits_{W \\in \\mathcal{W}} \\operatorname{empty}(W)$\nwhere $\\operatorname{emtpy}(W)$ the maximum number of empty tiles between one of $W$'s edges and the respective nearest screen edges. The objective is maximisation.\n$\\qquad \\displaystyle c(T) = \\left( \\min_{W \\in \\mathcal{W}} T(W)_3\\cdot T(W)_4 \\ ,\\ -\\sum\\limits_{W \\in \\mathcal{W}} \\operatorname{empty}(W)\\right)$."
] | [
null,
"https://i.stack.imgur.com/zG3bg.jpg",
null,
"https://i.stack.imgur.com/Ol6Vw.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9248469,"math_prob":0.95980847,"size":1181,"snap":"2019-51-2020-05","text_gpt3_token_len":258,"char_repetition_ratio":0.13169074,"word_repetition_ratio":0.0,"special_character_ratio":0.21676545,"punctuation_ratio":0.076595746,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9954472,"pos_list":[0,1,2,3,4],"im_url_duplicate_count":[null,3,null,3,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-12-11T23:12:47Z\",\"WARC-Record-ID\":\"<urn:uuid:d7fada0e-e10c-4c22-8ad7-22a64ae87342>\",\"Content-Length\":\"138083\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:1c6d3ef1-a966-4cc8-8303-a196e7999b90>\",\"WARC-Concurrent-To\":\"<urn:uuid:89a637fa-4502-47c9-8c2c-608d3d9c432c>\",\"WARC-IP-Address\":\"151.101.1.69\",\"WARC-Target-URI\":\"https://cs.stackexchange.com/questions/1274/how-to-score-a-given-arrangement-of-windows-on-a-screen-to-produce-good-layouts\",\"WARC-Payload-Digest\":\"sha1:SWHHCPHYEHORM7BQYC72KZGJIZRGBOLP\",\"WARC-Block-Digest\":\"sha1:C7RZLXEH7YWEA7OONBD2TZOKW3NX5JQS\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-51/CC-MAIN-2019-51_segments_1575540533401.22_warc_CC-MAIN-20191211212657-20191212000657-00528.warc.gz\"}"} |
https://2021.help.altair.com/2021.2/feko/topics/feko/user_guide/appendix/api_cadfeko_auto_generated/collection/reference_api_cadfeko_collection_cablepointscornercollection_feko_r.htm | [
"# CablePointsCornerCollection\n\nA collection of corner coordinates.\n\n## Example\n\napp = cf.GetApplication()\nproject = app:NewProject()\n\n-- Add a cable path to the model\n\ncorners = {cf.Point(0,0,0), cf.Point(0,1,0), cf.Point(1,1,0), cf.Point(1,0,0)}\n\n-- Move the corner points to N = 1\n\nfor i = 1, #path.Corners do\npath.Corners[i].N = 1\nend\n\n## Usage locations (collections)\n\nThe following objects contain the CablePointsCornerCollection collection:\n\n## Property List\n\nCount\nThe number of LocalCoordinates items in the collection. (Read only number)\n\n## Method List\n\nAdd a corner coordinate to the cable path.\nItem (index number)\nReturns the LocalCoordinates at the given index. (Returns a LocalCoordinates object.)\nModify (index number, point Coordinate)\nModify the corner coordinate at the given index.\nRemove (index number)\nRemove a corner from the cable path at the given index.\nSet (points List of Point)\nReplace the corners with a list of points.\n\n## Index List\n\n[number]\nReturns the LocalCoordinates at the given index in the collection. (Read LocalCoordinates)\n\n## Property Details\n\nCount\nThe number of LocalCoordinates items in the collection.\nType\nnumber\nAccess\n\n## Method Details\n\nAdd a corner coordinate to the cable path.\nInput Parameters\npoint(Coordinate)\nThe corner coordinate.\nItem (index number)\nReturns the LocalCoordinates at the given index.\nInput Parameters\nindex(number)\nThe index of the LocalCoordinates.\nReturn\nLocalCoordinates\nThe LocalCoordinates at the given index.\nModify (index number, point Coordinate)\nModify the corner coordinate at the given index.\nInput Parameters\nindex(number)\nThe corner index.\npoint(Coordinate)\nThe new corner coordinate.\nRemove (index number)\nRemove a corner from the cable path at the given index.\nInput Parameters\nindex(number)\nThe corner index.\nSet (points List of Point)\nReplace the corners with a list of points.\nInput Parameters\npoints(List of Point)\nA table of points."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.5867116,"math_prob":0.98044527,"size":1933,"snap":"2022-40-2023-06","text_gpt3_token_len":464,"char_repetition_ratio":0.20062208,"word_repetition_ratio":0.46357617,"special_character_ratio":0.24831867,"punctuation_ratio":0.14242424,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.95585114,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-02-08T14:00:57Z\",\"WARC-Record-ID\":\"<urn:uuid:a2d1e0ed-c7fd-4b97-9966-366917d3cdaf>\",\"Content-Length\":\"171336\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:abe1bf8d-3d48-4b34-9b76-4c5709bc59bd>\",\"WARC-Concurrent-To\":\"<urn:uuid:5bf72ec6-35d9-48b6-9232-1c1e4b97875f>\",\"WARC-IP-Address\":\"173.225.177.121\",\"WARC-Target-URI\":\"https://2021.help.altair.com/2021.2/feko/topics/feko/user_guide/appendix/api_cadfeko_auto_generated/collection/reference_api_cadfeko_collection_cablepointscornercollection_feko_r.htm\",\"WARC-Payload-Digest\":\"sha1:6LJPLPEYW5MYLAVTM6YSVZLL33XPLE56\",\"WARC-Block-Digest\":\"sha1:ZYXMRW2TMXA6MABRGKLXK2RPCGK64HBD\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-06/CC-MAIN-2023-06_segments_1674764500813.58_warc_CC-MAIN-20230208123621-20230208153621-00606.warc.gz\"}"} |
https://www.futureschool.com/australian-curriculum/queensland/mathematics-year-9-leading-to-b-and-c/ | [
"Latest Results:\n\n### QLD Year 9 leading to B and C Mathematics\n\n# TOPIC TITLE\n1 Study Plan Study plan – Year 9\nObjective: On completion of the course formative assessment a tailored study plan is created identifying the lessons requiring revision.\n2 Length Using the metre as a formal unit to measure perimeter\nObjective: On completion of the lesson the student will be able to calculate the perimeter of different shapes in metres.\n3 Length Using the formal unit of the centimetre to measure length and perimeter\nObjective: On completion of the lesson the student will be able to measure length and perimeter in centimetres.\n4 Measurement – Length Read and calculate distances on a map using the formal unit kilometre\nObjective: To read distances (km) from a map and calculate total distances between locations\n5 Length Compare and convert formal units of measurement\nObjective: On completion of the lesson the student will be able to use the formal units millimetre, centimetre, metre and kilometre to measure and convert.\n6 Length Problems with length.\nObjective: On completion of the lesson the student will be able to solve problems with length.\n7 Area Introducing the rules for finding the area of a rectangle and a parallelogram.\nObjective: On completion of the lesson the student will be able to investigate areas of rectangles and parallelograms using a given formula of multiplying measurements of sides.\n8 Area Finding the area of a triangle and other composite shapes.\nObjective: On completion of the lesson the student will be able calculate areas of triangles and shapes based on triangles, rectangles and parallelograms using given formulas.\n9 Area Larger areas: square metre, hectare, square kilometre.\nObjective: On completion of the lesson the student will be able to calculate larger areas using the correct square unit.\n10 Area Area of a trapezium.\nObjective: On completion of the lesson the student will be able calculate the area of all types of different shaped trapeziums using a given formula.\n11 Area Area of a rhombus.\nObjective: On completion of the lesson the student will be able to: identify a rhombus, learn how to find the formula for the area of a rhombus, and use it in solving problems.\n12 Area Area of a circle.\nObjective: On completion of the lesson the student will be able calculate the area of a circle, and also calculate the radius and diameter of a circle.\n13 Area Area of regular polygons and composite figures.\nObjective: On completion of the lesson the student will be able calculate the area of a number of different shapes by applying the appropriate formula.\n14 Area Problems with area.\nObjective: On completion of the lesson the student will be able to solve problems with area.\n15 Volume Introducing the formula for volume.\nObjective: On completion of the lesson the student will be able to: derive the formula for the volume of prisms, and calculate the area of prisms using the volume formula.\n16 Volume/capacity Problems with volume/capacity.\nObjective: Problem Solving: problems involving volume/capacity\n17 3-D shapes Viewing 3-D shapes.\nObjective: On completion of the lesson the student will be able to use conventional representations of three-dimensional shapes to show depth etc when drawing or viewing shapes from various angles.\n18 Volume Finding the volume of prisms\nObjective: On completion of the lesson the student will be able to: use formulae to find the volume of prisms, calculate the volume of a variety of prisms, and explain the relationship between units of length and units of volume.\n19 Multiplication Multiples and factors of whole numbers\nObjective: On completion of the lesson the student will be able to specify multiples and factors of whole numbers, and calculate the product of squared numbers.\n20 Fractions Finding equivalent fractions\nObjective: On completion of the lesson the student will be able to name and find fractions that represent equal amounts between halves, quarters and eighths – using diagrams and number lines.\n21 Fractions Multiplying and dividing to obtain equivalent fractions\nObjective: On completion of the lesson the student will be able to: obtain equivalent fractions using a number line or diagram, develop mental strategies to obtain equivalent fractions, and reduce a fraction to its lowest equivalent form.\n22 Fractions Reducing fractions to lowest equivalent form\nObjective: On completion of the lesson the student will be able to reduce a fraction to its lowest equivalent form by dividing the numerator and denominator by a common factor.\n23 Fractions Comparing and ordering fractions greater than (>) 1\nObjective: On completion of the lesson the student will be able to use diagrams, number lines and equivalent fractions to compare and order fractions greater than (>) one.\n24 Fractions Subtracting fractions from whole numbers\nObjective: On completion of the lesson the student will be able to: use a diagram to subtract fractions from a whole number, develop mental strategies for subtracting fractions from whole numbers, and recognise and use the written form for subtracting fractions from\n25 Fractions Adding and subtracting fractions with the same denominator\nObjective: To add and subtract fractions with the same denominator\n26 Fractions Adding and subtracting fractions with different denominators\nObjective: On completion of the lesson the student will be able to add and subtract fractions where one denominator is a multiple of the other.\n27 Fractions Multiplying fractions by whole numbers\nObjective: On completion of the lesson the student will be able to multiply simple fractions by whole numbers.\n28 Fractions Fractions of whole numbers\nObjective: On completion of the lesson the student will be able to calculate unit fractions of a collection.\n29 Fractions Multiplying fractions\nObjective: On completion of the lesson the student will be able to multiply fractions and reduce the answer to its lowest form.\n30 Fractions Multiplying mixed numbers (mixed numerals)\nObjective: On completion of the lesson the student will be able to multiply mixed numbers (mixed numerals) and reduce the answer to its lowest form.\n31 Fractions Finding reciprocals of fractions and mixed numbers (mixed numerals)\nObjective: On completion of the lesson the student will be able to find the reciprocals of fractions and mixed numbers (mixed numerals).\n32 Fractions Dividing fractions\nObjective: On completion of the lesson the student will be able to divide fractions.\n33 Fractions Dividing mixed numbers (mixed numerals)\nObjective: On completion of the lesson the student will be able to divide mixed numbers (mixed numerals).\n34 Fractions BODMAS\nObjective: To calculate answers for fraction and mixed number questions using BODMAS\n35 Decimals Adding decimals with a different number of decimal places\nObjective: On completion of the lesson the student will be able to add decimal numbers with different numbers of decimal places.\n36 Decimals Subtracting decimals with a different number of places\nObjective: On completion of the lesson the student will be able to subtract decimals with different numbers of decimal places.\n37 Decimals Multiplying decimals by 10, 100 and 1000\nObjective: On completion of the lesson the student will be able to multiply decimal numbers by one hundred and recognise the pattern formed when decimals are multiplied by ten, one hundred and one thousand.\n38 Decimals Multiplying decimals by whole numbers\nObjective: On completion of the lesson the student will be able to multiply decimals by whole numbers.\n39 Decimals Multiplication of decimals by decimals to two decimal places\nObjective: On completion of the lesson the student will be able to multiply decimals to two digits.\n40 Decimals Dividing decimals by 10, 100 and 1000\nObjective: On completion of the lesson the student will be able to divide decimal numbers by one hundred and recognise the pattern formed when decimals are divided by ten, one hundred and one thousand.\n41 Decimals Dividing decimal fractions by whole numbers\nObjective: On completion of the lesson the student will be able to divide decimal fractions by whole numbers.\n42 Decimals Dividing numbers by a decimal fraction\nObjective: On completion of the lesson the student will be able to divide numbers by a decimal fraction.\n43 Percentages Introduction to percentages, including relating common fractions to percentages\nObjective: On completion of the lesson the student will be able to recognise that the symbol % means ‘per cent’ and relate common fractions to a percentage.\n44 Percentages Changing fractions and decimals to percentages using tenths and hundredths\nObjective: On completion of the lesson the student will be able to change simple fractions to percentages and decimals to percentages by using place value conversion.\n45 Percentages Changing percentages to fractions and decimals\nObjective: On completion of the lesson the student will be able to change percentages to fractions and know how to change percentages to decimals.\n46 Percentages One quantity as a percentage of another\nObjective: On completion of the lesson the student will be able to find a percentage of an amount and how to express one quantity as a percentage of another.\n47 Percentages Calculating Percentages and Fractions of Quantities\nObjective: To find percentages and fractions of quantities and solve problems with percentages\n48 Algebraic expressions Algebraic expressions.\nObjective: On completion of the lesson the student will understand some of the short cuts used in writing algebraic expressions, and the student will be able to write algebraic expressions down in a way that is easier to understand.\n49 Algebraic expressions Substitution into algebraic expressions.\nObjective: On completion of the lesson the student will be able to replace pronumerals with numbers, and then perform the correct operations.\n50 Algebraic expressions Directed numbers: addition and subtraction.\nObjective: On completion of the lesson the student will be able to add and subtract positive and negative numbers in any combination, and understand adding and subtracting positive and negative pronumerals.\n51 Algebraic expressions Directed numbers: multiplication and division.\nObjective: On completion of the lesson the student will understand which combinations of signs produce a positive answer and which ones produce a negative answer.\n52 Algebraic expressions Simplifying algebraic expressions: adding like terms.\nObjective: On completion of the lesson the student will be able to simplify and evaluate numerical expressions containing patterns, and be able to simplify algebraic expressions that contain like terms.\n53 Algebraic expressions Simplifying algebraic Expressions: subtracting like terms.\nObjective: On completion of the lesson the student will be able to recognise the difference between like and unlike terms, and be able to simplify an expression using subtraction.\n54 Algebraic expressions Simplifying Algebraic expressions: combining addition and subtraction.\nObjective: On completion of the lesson the student will understand how to approach algebraic expressions questions and avoid the most common mistakes.\n55 Algebraic expressions Simplifying algebraic expressions: multiplication\nObjective: On completion of the lesson the student will be able to simplify expressions involving multiplication of pronumerals and write them in the simplest form.\n56 Algebraic expressions Simplifying algebraic expressions: division\nObjective: On completion of the lesson the student will be able to use all the operations needed for simplifying algebraic expressions.\n57 Time, 24-hour 24 hour time\nObjective: On completion of the lesson the student will be able to: tell the time accurately using twenty-four hour time, change the time from am and pm time to twenty-four hour time, and change the time from twenty-four hour time to am and pm time.\n58 Time, distance, speed Average speed\nObjective: On completion of the lesson the student will be able to understand what is meant by the speed of an object, read the instantaneous speed of a vehicle on a speedometer and find the average speed of an object.\n59 Time zones Time zones\nObjective: On completion of the lesson the student will be able to: recognise that there are different time zones, compare time zones, understand daylight saving and adjust times accordingly, and determine the local time in different regions.\n60 Lines and angles Mapping and grid references\nObjective: On completion of the lesson the student will be able to identify specific places on a map and use regions on a grid to locate objects or places.\n61 Geometry-angles Measuring angles\nObjective: On completion of the lesson the student will be able to measure any angle between 0 and 360 degrees using a protractor, and identify what type of angle it is.\n62 Geometry-angles Adjacent angles\nObjective: On completion of the lesson the student will be able to understand the parts of an angle, what adjacent angles are and how they are used to solve simple angle problems.\n63 Geometry-angles Complementary and supplementary angles\nObjective: On completion of the lesson the student will able to identify Complementary and Supplementary Angles and use this knowledge to solve simple geometric angle problems.\n64 Geometry-angles Vertically opposite angles\nObjective: On completion of the lesson the student will able to identify Vertically Opposite Angles and use this knowledge to solve simple geometric angle problems.\n65 Geometry-angles Angles at a Point.\nObjective: On completion of the lesson the student will able to identify Angles at a Point and use this knowledge and other angles concepts to solve simple geometric angle problems.\n66 Geometry-angles Parallel Lines.\nObjective: On completion of the lesson the student will able to identify corresponding, co-interior and alternate angles.\n67 Geometry-problems Additional questions involving parallel lines\nObjective: On completion of the lesson the student will able to complete two step parallel line questions, and identify other ways to solve them.\n68 Geometry-triangles Angle sum of a triangle\nObjective: On completion of the lesson the student will able to identify and use the angle sum of a triangle theorem to solve geometric problems.\n69 Geometry-triangles Exterior angle theorem\nObjective: On completion of the lesson the student will able to identify and use the exterior angle of a triangle theorem to solve geometric questions.\n70 Special triangles Special triangles\nObjective: On completion of the lesson the student will able to identify an equilateral and an isosceles triangle and solve geometry questions involving these triangles.\nObjective: On completion of the lesson the student will able to find missing angles by using the fact that a quadrilateral’s angle sum is 360 degrees.\n72 Geometry-constructions Geometric constructions\nObjective: On completion of the lesson the student will able complete constructions with a ruler and a pair of compasses.\n73 Geometry To identify collinear points, coplanar lines and points in 2 and 3 dimensions\nObjective: On completion of the lesson the student will use correct terms to describe points, lines, intervals and rays.\n74 Geometry – angles To determine angle labelling rules, naming angles according to size, angle bisector properties and related algebra\nObjective: On completion of the lesson the student will label angles, use a protractor and perform calculations using algebra involving angles.\n75 Geometry-constructions Angle bisector construction and its properties (Stage 2)\nObjective: On completion of the lesson the student will be able to bisect an angle using a pair of compasses and a straight edge.\n76 Geometry part 2 Congruent triangles: Tests 1 and 2\nObjective: To recognise congruent triangles and matching sides and angles using SSS and SAS\n77 Geometry-congruence Congruent triangles, Test 3 and 4\nObjective: On completion of the lesson the student will be able to identify other tests to use to show two triangles are congruent.\n78 Geometry-congruence Proofs and congruent triangles.\nObjective: On completion of the lesson the student will be able to set out a formal proof to show that two triangles are congruent.\n79 Similar triangles Similar triangles\nObjective: On completion of the lesson the student will be able to identify which test to use to show two triangles are similar.\n80 Geometry part 2 Using Similar Triangles to Calculate Lengths\nObjective: To determine unknown sides and angles of similar triangles\n81 Overlapping triangles Examples involving overlapping triangles\nObjective: On completion of the lesson the student will be able to calculate unknown sides in overlapping or adjacent similar triangles.\n82 Pythagoras Find the hypotenuse\nObjective: On completion of this lesson the student will be able to use Pythagoras’ Theorem to calculate the length of the hypotenuse.\n83 Pythagoras Pythagorean triples\nObjective: On completion of the lesson the student will be able to use the 3-4-5 Pythagorean triple.\n84 Pythagoras Find the hypotenuse Part 2\nObjective: On completion of this lesson the student will be able to use Pythagoras’ Theorem to calculate the length of the hypotenuse using decimals and surds.\n85 Pythagoras Calculating a leg of a right-angled triangle\nObjective: On completion of this lesson the student will be able to use Pythagoras’ Theorem to calculate the length of one of the shorter sides of a right triangle.\n86 Trigonometry-ratios Trigonometric ratios.\nObjective: On completion of the lesson the student will be able to identify the hypotenuse, adjacent and opposite sides for a given angle in a right angle triangle. The student will be able to label the side lengths in relation to a given angle e.g. the side c is op\n87 Trigonometry-ratios Using the calculator.\nObjective: On completion of the lesson the student will be able to use the calculator to find values for the sine, cosine and tangent ratios of acute angles.\n88 Trigonometry part 1 Using the Trigonometric Ratios to find unknown length [Case 1 Sin]\nObjective: To use the sine ratio to calculate the opposite side of a right-angled triangle\n89 Trigonometry-ratios Using the trigonometric ratios to find unknown length. [Case 2 Cosine].\nObjective: On completion of the lesson the student will be able to use the cosine ratio to find the length of the adjacent side of a right angle triangle.\n90 Trigonometry-ratios Using the trigonometric ratios to find unknown length. [Case 3 Tangent Ratio].\nObjective: On completion of the lesson the student will be able to use the tangent ratio to calculate the length of the opposite side in a right angle triangle.\n91 Trigonometry-ratios Unknown in the denominator. [Case 4].\nObjective: On completion of the lesson the student will understand how to use the trig ratios to calculate lengths and distances when the denominator is unknown.\n92 Algebraic expressions Expanding algebraic expressions: multiplication\nObjective: On completion of the lesson the student will be able mentally to multiply and remove parentheses from simple algebraic expressions in one step.\n93 Algebraic expressions Expanding algebraic expressions: negative multiplier\nObjective: On completion of the lesson the student will be able to expand expressions using a negative multiplier.\n94 Algebraic expressions Expanding and simplifying algebraic expressions\nObjective: On completion of the lesson the student will be familiar with expanding and simplifying algebraic expressions.\n95 Algebraic equations Solving equations containing addition and subtraction\nObjective: On completion of the lesson the student will understand how solve simple equations involving addition and subtraction by moving everything but the pronumeral onto one side of the equation, leaving the pronumeral by itself on the other side.\n96 Algebraic equations Solving equations containing multiplication and division\nObjective: On completion of the lesson the student will be able to solve simple equations involving all operations.\n97 Algebraic equations Solving two step equations\nObjective: On completion of the lesson the student will be able to solve two step equations.\n98 Algebraic equations Solving equations containing binomial expressions\nObjective: On completion of the lesson the student will be able to move terms in binomial equations.\n99 Algebraic equations Equations involving grouping symbols.\nObjective: On completion of the lesson the student will be able to solve equations using grouping symbols\n100 Algebraic equations Equations involving fractions.\nObjective: On completion of the lesson the student will know how to solve equations using fractions.\n101 Algebra- formulae Equations resulting from substitution into formulae.\nObjective: On completion of the lesson the student will be able to substitute into formulae and then solve the resulting equations.\n102 Algebra- formulae Changing the subject of the formula.\nObjective: On completion of the lesson the student will be able to move pronumerals around an equation using all the rules and operations covered previously.\n103 Statistic-probability Probability of Simple Events\nObjective: On completion of the lesson the student will be able to understand the probability of simple events.\n104 Statistic-probability Rolling a pair of dice\nObjective: On completion of the lesson the student will be capable of ascertaining the probability of certain results when 2 dice are thrown simultaneously.\n105 Statistic-probability Experimental probability\nObjective: On completion of this lesson the student will be able to find the probabilities in an experimental trial.\n106 Statistic-probability Tree diagrams – not depending on previous outcomes\nObjective: On completion of the lesson the student will be confident in drawing tree diagrams to list outcomes of a multi stage probability problem and then finding probabilities of certain events not depending on previous outcomes.\n107 Statistic-probability Tree diagrams – depending on previous outcomes\nObjective: On completion of the lesson the student will be confident in drawing tree diagrams to list outcomes of other multi stage probability problems and then finding probabilities of certain events depending on previous outcomes.\n108 Statistics Frequency distribution table\nObjective: On completion of the lesson the student will be able to construct a frequency distribution table for raw data and interpret the table.\n109 Statistics Frequency histograms and polygons\nObjective: On completion of the lesson the student will be able to construct and interpret frequency histograms and polygons.\n110 Statistics Relative frequency\nObjective: On completion of the lesson the student will be able to collect, display and make judgements about data.\n111 Statistics The range.\nObjective: On completion of the lesson the student will be able to determine the range of data in either raw form or in a frequency distribution table.\n112 Statistic-probability Binomial Theorem – Pascal’s Triangle\nObjective: On completion of this lesson the student will use Pascal’s triangle and the binomial theorem to write the expansion of binomial expressions raised to integer powers.\n113 Statistic-probability Binomial probabilities using the Binomial Theorem\nObjective: On completion of the lesson the student will be able to solve certain types of probability questions using the binomial theorem\n114 Statistic-probability Counting techniques and ordered selections – permutations\nObjective: On completion of this lesson the student will be competent in using some new counting techniques used for solving probability.\n115 Statistics Stem and Leaf Plots along with Box and Whisker Plots\nObjective: On completion of the lesson the student will be familiar with vocabulary for statistics including quartiles, mode, median, range and the representation of this information on a Box and Whisker Plot.\nObjective: On completion of this lesson the student will understand the properties that classify quadrilaterals.\n117 Geometry-quadrilaterals Using the Properties of a Parallelogram\nObjective: On completion of this lesson the student will be able to use and prove the properties of a parallelogram.\n118 Geometry-quadrilaterals Proving a Shape is a Parallelogram\nObjective: On completion of this lesson the student will be able to use properties to prove a given quadrilateral is a parallelogram.\n119 Geometry-quadrilaterals Properties of the Rectangle, Square and Rhombus\nObjective: On completion of this lesson students will be able to use the properties of the rectangle, square and rhombus for formal proofs and to find values.\n120 Geometry-quadrilaterals Properties of the Trapezium and Kite\nObjective: On completion of this lesson students will be able to use the properties of the trapezium and kite for formal proofs and to find values.\nObjective: To establish the properties of quadrilaterals in the number plane\n122 Rules for indices/exponents Adding indices when multiplying terms with the same base\nObjective: On completion of the lesson the student will know how to use the index law of addition of powers when multiplying terms with the same base.\n123 Rules for indices/exponents Subtracting indices when dividing terms with the same base\nObjective: On completion of the lesson the student will know how to use the index law of subtraction of powers when dividing terms with the same base.\n124 Rules for indices/exponents Multiplying indices when raising a power to a power\nObjective: On completion of the lesson the student will use the law of multiplication of indices when raising a power to a power.\n125 Rules for indices/exponents Multiplying indices when raising to more than one term\nObjective: On completion of the lesson the student will be able to use the law of multiplication of indices when raising more than one term to the same power.\n126 Rules for indices/exponents Terms raised to the power of zero\nObjective: On completion of the lesson the student will learn how to evaluate or simplify terms that are raised to the power of zero.\n127 Rules for indices/exponents Negative Indices\nObjective: On completion of the lesson the student will know how to evaluate or simplify expressions containing negative indices.\n128 Fractional indices/exponents Fractional indices\nObjective: On completion of the lesson the student will know how to evaluate or simplify expressions containing fractional indices.\n129 Scientific notation Scientific notation with larger numbers\nObjective: On completion of the lesson the student will be able to change numbers greater than 1 to scientific notation.\n130 Scientific notation Scientific notation with small numbers\nObjective: On completion of the lesson the student will be able to change numbers between zero and 1 to scientific notation.\n131 Scientific notation Changing scientific notation to numerals\nObjective: On completion of the lesson the student will be able to change numbers written in scientific notation to basic numerals and be capable of solving problems on the calculator in scientific notation.\n132 Surds Introducing surds\nObjective: On completion of the lesson the student will be able to identify and know the properties of surds as irrational numbers and be able to distinguish them from rational numbers.\n133 Algebra-factorising Simplifying easy algebraic fractions.\nObjective: On completion of the lesson the student will understand how to simplify algebraic fractions by factorising.\n134 Algebraic fractions Simplifying algebraic fractions using the index laws.\nObjective: On completion of the lesson the student will be able to simplify most algebraic fractions using different methodologies.\n135 Algebra-negative indices Algebraic fractions resulting in negative indices.\nObjective: On completion of the lesson the student will be able to understand how to simplify an algebraic fractional expression with a negative index, and also how to write such an expression without a negative index.\n136 Factorisation Factorisation of algebraic fractions including binomials.\nObjective: On completion of the lesson the student should be able to simplify more complex algebraic fractions using a variety of methods.\n137 Algebraic fractions-binomial Cancelling binomial factors in algebraic fractions.\nObjective: On completion of the lesson the student should be able to factorise binomials to simplify fractions.\n138 Simultaneous equns Simultaneous equations\nObjective: On completion of the lesson the student will be able to solve 2 equations with 2 unknown variables by the substitution method.\n139 Simultaneous equns Elimination method\nObjective: On completion of the lesson the student will be able to solve 2 equations with 2 unknown variables by the elimination method.\n140 Simultaneous equns Elimination method part 2\nObjective: On completion of the lesson the student will be able to solve all types of simultaneous equations with 2 unknown variables by the elimination method.\n141 Simultaneous equns Applications of simultaneous equations\nObjective: On completion of this lesson the student will be able to derive simultaneous equations from a given problem and then solve those simultaneous equations.\n142 Coordinate geometry Solve by graphing\nObjective: On completion of the lesson students will use the slope intercept form of a line to create graphs and find points of intersection.\n143 Exam Exam – Year 9 – Level 5: Maths B & C\nObjective: Exam"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.8344682,"math_prob":0.96292907,"size":30084,"snap":"2022-40-2023-06","text_gpt3_token_len":6575,"char_repetition_ratio":0.33005318,"word_repetition_ratio":0.33318672,"special_character_ratio":0.19970748,"punctuation_ratio":0.07874174,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99955636,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-09-30T19:13:58Z\",\"WARC-Record-ID\":\"<urn:uuid:d41594a8-f722-441a-b6b3-31405b5511a5>\",\"Content-Length\":\"100189\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:ddb8c107-466a-4f26-b914-eb385348f32a>\",\"WARC-Concurrent-To\":\"<urn:uuid:58c45017-6d5a-4344-8d0b-dd613222dec2>\",\"WARC-IP-Address\":\"141.193.213.11\",\"WARC-Target-URI\":\"https://www.futureschool.com/australian-curriculum/queensland/mathematics-year-9-leading-to-b-and-c/\",\"WARC-Payload-Digest\":\"sha1:IJQJEWW4PQOC7LTCL2DG2A5VDAGNXILF\",\"WARC-Block-Digest\":\"sha1:KZKJHCJA4IS3GUVKZPBBCJN2LIFMZ4NZ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-40/CC-MAIN-2022-40_segments_1664030335504.22_warc_CC-MAIN-20220930181143-20220930211143-00435.warc.gz\"}"} |
https://math.stackexchange.com/questions/2332712/constant-maps-are-smooth | [
"Constant Maps are smooth.\n\nLet $M$ , $N$, and $P$ be smooth manifolds with or without boundary.\n\nEvery constant map $c: M\\rightarrow N$ is smooth.\n\nProof: Let $c: M \\rightarrow N$ be a constant map. Let $p \\in M$. Smoothness of $c$ means there are charts $(U,\\phi)$ of $p$ and $(V,\\psi)$ of $c(p)$ such that $c(U) \\subseteq V$ and $\\psi \\circ c \\ \\circ \\phi^{-1}$ is smooth. Since $c$ is a constant map we know that $c(p)=y$ for every $p \\in M$.\n\nThis is as far as I got with the proof. I'm a bit lost on how to finish the proof using the fact that c is a constant map to show that $c: M \\rightarrow N$ is smooth.\n\nI'd appreciate hints or advice instead of a full solution to the problem that way it doesn't spoil the problem for me.\n\nI'm using Lee's Introduction to Smooth Manifolds.\n\n• I think you meant $\\phi \\circ c \\circ \\psi^-$ is smooth, right? Because otherwise your composition doesn't make sense. – user456218 Jun 22 '17 at 18:50\n• Are you allowed to use the fact that constant maps between open subsets of Euclidean spaces are smooth? (If not, this is easy to prove) – M10687 Jun 22 '17 at 18:51\n\nWe have chosen some chart $\\phi \\colon U \\rightarrow \\phi(U) \\subseteq \\mathbb{R}^n$ on $M$ and a chart $\\psi \\colon V \\rightarrow \\psi(V) \\subseteq \\mathbb{R}^m$ on $N$. We want to show that $\\psi \\circ c \\circ \\phi^{-1}$ is smooth given $c$ is constant.\n\nHints: 1. What is the domain and codomain of the map $\\psi \\circ c \\circ \\phi^{-1}$\n\n1. Is a constant map $k \\colon \\mathbb{R}^n \\rightarrow \\mathbb{R}^m$ smooth?\n• Domain would be R^n and codomain would be R^m. wouldn't the dimensions need to be the same for k: R^n ---> R^m? – Alexander King Jun 22 '17 at 19:40\n• The dimension to be the same is unnecessary. The question is whether a constant function between real spaces is smooth and if so, whether the $\\psi \\circ c \\circ \\phi^{-1}$ is a consant function defined on a subset of a real space. – Radek Suchánek Jun 22 '17 at 21:02\n\nHint: You just need to write it down clearly. $c$ is smooth requires you to show that $\\phi \\circ c \\circ \\psi^-$ is smooth. Now as $c$ is constant,for all arguments, you are left with $\\phi(y)$ in the end. Now this is just a constant. Use definition of smoothness now\n\nEvery constant map is smooth.\n\nSay $$f:M \\rightarrow N$$ is a constant map. Here $$f$$ is smooth because the coaordinate representation of $$f$$ i.e $$\\theta f\\phi^{-1} :R^{m}\\rightarrow R^n$$ is a constant map as a map between 2 euclidean spaces where $$(u,\\phi)$$ and $$(v,\\theta)$$ are charts around $$p$$ and $$q$$ respectively where $$f(p)=q$$ $$\\forall$$ $$p \\in$$ $$M$$. Here dimension of $$M$$ and $$N$$ are assumed to be $$m$$ and $$n$$ respectively. We already know from multi variable calculus that any constant map between two euclidean spaces is always smooth. Hence by definiton of a smooth map between smooth manifolds $$f$$ is smooth."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9071071,"math_prob":0.9999603,"size":753,"snap":"2019-26-2019-30","text_gpt3_token_len":225,"char_repetition_ratio":0.12416556,"word_repetition_ratio":0.0,"special_character_ratio":0.30677292,"punctuation_ratio":0.10650887,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":1.0000018,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-06-19T14:41:20Z\",\"WARC-Record-ID\":\"<urn:uuid:f1ea1b23-50a7-45e2-ab47-a069cb3a6d71>\",\"Content-Length\":\"149473\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:79f00d4f-8524-4642-9db9-b7c7006543a4>\",\"WARC-Concurrent-To\":\"<urn:uuid:4f8c631a-9f7a-48b4-b372-2c31e7f6d636>\",\"WARC-IP-Address\":\"151.101.193.69\",\"WARC-Target-URI\":\"https://math.stackexchange.com/questions/2332712/constant-maps-are-smooth\",\"WARC-Payload-Digest\":\"sha1:ISC3KGASCF4DQIRBYBIZYPSRXYSMAGBH\",\"WARC-Block-Digest\":\"sha1:CBMCWJRAXLUVMIOMF3SEDUSFL5QZEA7A\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-26/CC-MAIN-2019-26_segments_1560627999000.76_warc_CC-MAIN-20190619143832-20190619165832-00196.warc.gz\"}"} |
https://www.saveonmedicals.com/manufacturer/aristo-pharmaceuticals-pvt-ltd | [
"## Address Of ARISTO PHARMACEUTICALS PVT.LTD:\n\n23-A, Shah Industrial Estate, Off Veera Desai Road, Andheri (West), Mumbai \u0013 400 053, India.\n30 26739999\n\nRs. 16.00\nRs. 17.20\n\nRs. 8.09\nRs. 8.70\n\nRs. 83.60\nRs. 95.00\n\nRs. 333.08\nRs. 378.50\n\nRs. 290.40\nRs. 330.00\n\nRs. 69.75\nRs. 75.00\n\nRs. 13.76\nRs. 14.80\n\nRs. 59.08\nRs. 69.50\n\nRs. 73.48\nRs. 83.50\n\nRs. 574.13\nRs. 675.45\n\nRs. 76.56\nRs. 87.00\n\nRs. 15.94\nRs. 18.75\n\nRs. 27.41\nRs. 32.25\n\nRs. 111.97\nRs. 120.40\n\nRs. 31.62\nRs. 34.00\n\nRs. 100.30\nRs. 118.00\n\nRs. 31.44\nRs. 33.81\n\nRs. 39.24\nRs. 43.60\n\nRs. 95.92\nRs. 109.00\n\nRs. 602.79\nRs. 648.16\n\nRs. 82.79\nRs. 97.40\n\nRs. 52.67\nRs. 59.85\n\nRs. 330.00\nRs. 375.00\n\nRs. 38.10\nRs. 44.82\n\nRs. 9.34\nRs. 10.04"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.5711715,"math_prob":0.99438065,"size":1881,"snap":"2019-51-2020-05","text_gpt3_token_len":859,"char_repetition_ratio":0.1358551,"word_repetition_ratio":0.06790123,"special_character_ratio":0.40085062,"punctuation_ratio":0.23373984,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98079854,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-12-09T09:15:41Z\",\"WARC-Record-ID\":\"<urn:uuid:010e79c3-6eb5-4ec2-a9f9-094b5c50160f>\",\"Content-Length\":\"155849\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:1a782e76-0cd3-4be6-a0e2-dc1b177c1533>\",\"WARC-Concurrent-To\":\"<urn:uuid:12b4661f-5a3c-4ca6-967f-2021fd7ba3a0>\",\"WARC-IP-Address\":\"104.28.2.55\",\"WARC-Target-URI\":\"https://www.saveonmedicals.com/manufacturer/aristo-pharmaceuticals-pvt-ltd\",\"WARC-Payload-Digest\":\"sha1:2XEVB5UGAWVMDTCMUK46EVETSCG3XTAX\",\"WARC-Block-Digest\":\"sha1:7RJJ6OW7OU7F5OAFUFY7XPGR3EH6IIP6\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-51/CC-MAIN-2019-51_segments_1575540518337.65_warc_CC-MAIN-20191209065626-20191209093626-00384.warc.gz\"}"} |
https://prower.cn/docid/1536556081928459595 | [
"# 硫酸\n\n### 基本信息\n\n 中文名 硫酸 外文名 Sulfuric acid 化学式 H2SO4 熔点 10.371 ℃ 密度 1.8305 g/cm³ 水溶性 与水任意比互溶 沸点 337 ℃ 分子量 98.078 摩尔质量 98.0734 折射率 1.41827 汽化热 0.57 kJ/g (STP) 标况状态 透明无色无臭液体 动态粘滞度 0.021 Pa s (25℃) 热容量 1.416 J/(g K) (STP) 表面张力 0.0735 N/m 蒸汽压 6×10⁻⁵ mmHg CAS号 7664-93-9 熔化热 0.1092 kJ/g (STP) 外观 透明无色无臭液体\n\n### 物理性质\n\n2H2SO4 ⇌ H3SO4+ + HSO4- (主要)\n\nH2O + H2SO4 ⇌ HSO4- + H3O+\n\n### 化学性质\n\nNaCl + H2SO4 == NaHSO4 + HCl(不加热都能很快反应)\n\nKNO3 + H2SO4 → KHSO4 + HNO3\n\nHNO3 + H2SO4 → NO2+ + H2O + HSO4-\n\nCH3COOH + HSO4 → CH3C(OH)2+ + HSO4-\n\nH2SO3F+ H2SO4 → H3SO4+ + SO3F-(氟磺酸酸性更强)\n\n1.脱水性\n\nC12H22O11 == == 12C + 11H2O\n\nC + H2SO4(浓)== == CO↑+ SO2↑ + H2O\n\n2.强氧化性\n\n2HBr + H2SO4(浓) = Br+ SO2+ 2H2O\n\n3H2S + H2SO4(浓) = 4 S↓+ 4H2O\n\n8HI + H2SO4(浓) = 4I2 + H2S+ 4H2O\n\nZn + 2H2SO4(浓) =ZnSO4 + SO2 + 2H2O\n\n3Zn + 4H2SO4(浓) = 3ZnSO4 + S + 4H2O\n\n4Zn + 5H2SO4(浓) = 4ZnSO4 + H2S↑+ 4H2O\n\n(1)与金属反应\n\n①常温下浓硫酸能使铁、铝等金属钝化。②加热时,浓硫酸可以与除铱,钌之外的所有金属(包括金,铂)反应,生成高价金属硫酸盐,本身被还原成SO,S,HS或金属硫化物\n\nCu + 2H2SO4(浓)= =CuSO4 + SO2↑ + 2H2O\n\n2Fe + 6H2SO4(浓) = = Fe2(SO4)3 +3SO2↑ + 6H2O\n\nPt + 4H2SO4(浓) = = Pt(SO4)2 + 2SO2↑ + 4H2O(338℃的沸腾浓硫酸中,腐蚀率0.4mm/年以上;金被腐蚀的速度则慢得多)\n\n(2)与非金属反应\n\nC + 2H2SO4(浓)== CO2↑+ 2SO2↑ + 2H2O\n\n2S + 2H2SO4(浓) == 3SO2↑ + 2H2O\n\n2P + 5H2SO4(浓)= = 2H3PO4 + 5SO2↑ + 2H2O\n\n(3)与其他还原性物质反应\n\nH2S + H2SO4(浓) == S↓+ SO2 + 2H2O\n\n2HBr + H2SO4(浓) == Br2 + SO2 + 2H2O\n\n8HI + H2SO4(浓) == 4I2 + H2S + 4H2O\n\n3.可与碱反应生成相应的硫酸盐和水;\n\n4.可与氢前金属在一定条件下反应,生成相应的硫酸盐和氢气;\n\n5.加热条件下可催化蛋白质、二糖和多糖的水解;\n\n6.能与指示剂作用,使紫色石蕊试液变红,使无色酚酞试液不变色。\n\n### 制备方法\n\nS + O2 ==== SO2\n\n4FeS + 11O2 === 8SO2 + 2Fe2O3\n\n2SO2 + O2 ==== 2SO3(可逆反应)\n\nSO3 + H2SO4 == H2S2O7(焦硫酸)\n\nH2S2O7 + H2O == 2H2SO4\n\n4FeS + 11O2 == 8SO2 + 2Fe2O3\n\n1.制取二氧化硫(沸腾炉)\n\n4FeS + 11O2 == 8SO2 + 2Fe2O3\n\nSO2 + H2O ==== H2SO3\n\n3.亚硫酸氧化得硫酸。\n\n2H2SO3 + O2 ==== 2H2SO4\n\n1.氨酸法增浓低浓度二氧化硫气体生产硫酸方法\n\n2.采用就地再生的硫酸作为催化剂的一体化工艺\n\n3.草酸生产中含硫酸废液的回收利用\n\n4.从芳族化合物混酸硝化得到废硫酸的纯化与浓缩工艺\n\n5.从氧化钛生产过程中排出的废硫酸溶液的再生方法\n\n6.从稀硫酸中分离有机磷化合物和其它杂质的方法\n\n7.从制备2-羟基-4-甲巯基丁酸(MHA)工艺的含硫副产物中回收硫酸的方法\n\n8.催化氧化回收含有机物废硫酸的方法\n\n9.电瓶用硫酸生产装置\n\n10.二氧化硫源向硫酸的液相转化方法\n\n11.沸腾炉焙烧硫磺制备硫酸的方法\n\n12.沸腾炉掺烧硫磺生产装置中稀酸的回收利用\n\n13.高浓二氧化硫气三转三吸硫酸生产方法\n\n14.高温浓硫酸液下泵耐磨轴套\n\n15.高效阳极保护管壳式浓硫酸冷却器\n\n16.节能精炼硫酸炉装置\n\n17.精苯再生酸焚烧制取硫酸的方法\n\n18.利用废硫酸再生液的方法和装置\n\n19.利用含硫化氢的酸性气体与硫磺联合制取高浓度硫酸\n\n20.利用含硫化氢的酸性气体制取高浓度硫酸"
] | [
null
] | {"ft_lang_label":"__label__zh","ft_lang_prob":0.9423336,"math_prob":0.9994986,"size":10295,"snap":"2022-27-2022-33","text_gpt3_token_len":12613,"char_repetition_ratio":0.057040133,"word_repetition_ratio":0.013129103,"special_character_ratio":0.23137446,"punctuation_ratio":0.052041635,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98561877,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-06-25T11:37:22Z\",\"WARC-Record-ID\":\"<urn:uuid:5c6f970d-79d0-4ac0-89d7-eee63bcdc132>\",\"Content-Length\":\"42635\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:4d21104d-ef38-43f3-8c4d-8d4475c80f6f>\",\"WARC-Concurrent-To\":\"<urn:uuid:66ebc93b-31b7-4b6a-9aaf-887aa69559d5>\",\"WARC-IP-Address\":\"121.196.144.202\",\"WARC-Target-URI\":\"https://prower.cn/docid/1536556081928459595\",\"WARC-Payload-Digest\":\"sha1:UKALA3FJF6YUDDHS26OWOG2JKSYVTKQI\",\"WARC-Block-Digest\":\"sha1:O37FRIVY5SAGXXVICPAJOQWLC25IVYJW\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-27/CC-MAIN-2022-27_segments_1656103034930.3_warc_CC-MAIN-20220625095705-20220625125705-00389.warc.gz\"}"} |
http://www.goldenkstar.com/matrix-algebra-school-maths-software.htm | [
"# MATRIX ALGEBRA",
null,
"## Download Genius Maker Educational Software - All Softwares in One pack",
null,
"### Features of Matrix Algebra Software:\n\nThe Matrix algebra is a mathematics software for performing algebraic operations on matrix. Assume 2 matrices namely A and B are given. This software facilitates to do operations such as Matrix addition, Matrix subtraction and Matrix multiplication of any order not exceeding 4 x 4. The multiplication support available for both scalar multiplication and vector multiplication. The typical operations, which a user can perform are as given below.\n\n2A + 5B\n\n23A - 34B\n\n6A x 5B\n\n### How to start with Matrix Algebra software ?\n\n• Open Genius Maker software and click \"Matrix algebra\" button. It opens the Matrix algebra window as shown above.\n• It automatically shows a mathematical equation in the equation box and numbers in the matrix boxes A and B. These numbers are provided to assist you to quick start Matrix algebra software. You may clear that data by pressing the \"Clear data\" button and enter a fresh set of values whenever needed. Similarly you may change the equation also from the top panel.\n\nEXAMPLE - 1\n\n• Let us take an example.\n• Set the equation as 1A + 2B\n• Define the size of the Matrix-A as 3 x 2\n• You may see that the size of Matrix-A changes accordingly.\n• Click the \"Clear data\" button of Matrix - A\n• Now enter the values of Matrix - A as below.\n\n5 6\n\n3 2\n\n2 1\n\n• Define the size of the Matrix-B as 3 x 2\n• You may see that the size of Matrix-B changes accordingly.\n• Click the \"Clear data\" button of Matrix - B\n• Now enter the values of Matrix - B as below.\n\n3 5\n\n1 4\n\n4 2\n\n• Click \"Evaluate\" button on the equation box.\n• You may see that the result appears in the resultant matrix box.\n\nEXAMPLE - 2\n\n• Now let us try an example for matrix multiplication.\n\n• Set the equation as 3A x 4B\n• Let us keep the Matrix - A of the previous example same.\n• Define the size of the Matrix-B as 2 x 4\n• You may see that the size of Matrix-B changes accordingly.\n• Click the \"Clear data\" button of Matrix - B\n• Now enter the values of Matrix - B as below.\n\n2 1 5 7\n\n4 6 3 2\n\n• Click \"Evaluate\" button on the equation box.\n• You may see that the result appears in the resultant matrix box as a 3 x 4 matrix.\n• Now you may try with different equations, different matrix sizes and values for matrices. The maximum supported size of a row or a column is 4.\n\n### Additional Features :\n\n• Copying a matrix: Whenever you need to copy any matrix to another one, make use of the \"copy\" and \"paste\" buttons suitably. For example, if you want to do some operations on the resultant matrix, which is currently displayed, then press the \"copy\" button on the resultant matrix box and then click \"paste\" button of either Matrix - A or Matrix - B based on your need. Similarly you can copy any of the 3 matrix to any other 2 matrices. An exception is that you cannot paste a matrix on to the resultant matrix box.\n\n## Download Genius Maker Educational Software - All Softwares in One pack",
null,
"QUICK LINKS MATHEMATICS Matrix Algebra PHYSICS Doppler Effect CHEMISTRY Number System Determinant Unit Converter Electrical Resistance Periodic Table Progressions Graph Plotter Linear Motion Transverse Waves Gas Laws Introduction Triangle Solver Geometry Solver Motion Under Gravity Longitudinal Waves pH Value FAQ Equation Solver Polynomial expansion Refraction of Rays Radioactive Decay Molecular Weight Start Genius Maker Curve Fitting Permutation Combination Lens & Mirrors Colour Theory",
null,
""
] | [
null,
"http://www.goldenkstar.com/images-school-software-education/1gm-school-software-science-education.gif",
null,
"http://www.goldenkstar.com/images-school-software-education/free-download-mathematics-science-software.gif",
null,
"http://www.goldenkstar.com/images-school-software-education/free-download-mathematics-science-software.gif",
null,
"http://www.goldenkstar.com/images-school-software-education/cbse-syllabus.gif",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.85189223,"math_prob":0.95843786,"size":2923,"snap":"2019-13-2019-22","text_gpt3_token_len":710,"char_repetition_ratio":0.15827338,"word_repetition_ratio":0.2455516,"special_character_ratio":0.24769072,"punctuation_ratio":0.06725664,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9923421,"pos_list":[0,1,2,3,4,5,6,7,8],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-03-21T11:53:05Z\",\"WARC-Record-ID\":\"<urn:uuid:b9e122d0-762f-4e46-830e-d43817196ef6>\",\"Content-Length\":\"25645\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:bc5bd91d-e803-49b9-bc30-769697bcda49>\",\"WARC-Concurrent-To\":\"<urn:uuid:01cbc724-c7c7-43dc-8e8a-2bd054f9f6f9>\",\"WARC-IP-Address\":\"143.95.252.22\",\"WARC-Target-URI\":\"http://www.goldenkstar.com/matrix-algebra-school-maths-software.htm\",\"WARC-Payload-Digest\":\"sha1:TD5KXFB6WISWOTLZAZLMQRN3QIY2ET6Q\",\"WARC-Block-Digest\":\"sha1:6OHL3CHZHZG7DBFP7GNRSW6UYT3IEXJM\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-13/CC-MAIN-2019-13_segments_1552912202523.0_warc_CC-MAIN-20190321112407-20190321134407-00260.warc.gz\"}"} |
https://mathematica.stackexchange.com/questions/7363/passing-unquoted-strings-poor-mans-enumeration?noredirect=1 | [
"# Passing unquoted strings (poor man's enumeration)\n\nI would like to be able to pass an unquoted string as a parameter to a Mathematica function [that I am writing] and have it show up without evaluation if the string happens to be defined. Thus I would like\n\nClear[\"Global*\"]\nf[x_] := Print[ToString[x]];\nf[Middle] (* prints the string Middle *)\nMiddle = 3\nf[Middle] (* prints the string Middle *)\n\n\nObviously this cannot work the way I've written it. Yet it is legal to write\n\nPlot[g[x],{x,0,3}, PlotStyle->Black]\n\n\nand Black happens to be a protected variable, so it will never be defined.\n\nHow can I emulate, or come close to emulating, this behavior. I'm willing to put up with some compromises in the function invocation syntax (in particular, the option syntax opt->Middle would be fine).\n\nApologies if this is somewhere in the docs. I couldn't find it...\n\nThanks.\n\nAddendum: While J.M.'s solution answers the question I posed above, I would also like the following to work:\n\nClear[\"Global*\"]\nSetAttributes[foo,HoldAll];\nfoo[x_] := Print[ToString[Unevaluated[x]]];\nTable[foo[i],{i,{a,b,c}}] (* prints {i,i,i}, as expected *)\nTable[foo[Evaluate[i]], {i,{a,b,c}}] (* prints {a,b,c} as expected *)\na = 3\nTable[foo[Evaluate[i]], {i,{a,b,c}}] (* prints {3,b,c} *)\n\n\nI would like the last line to print {a,b,c} just like the one before it - that is, I'd like i evaluated only once. Am I asking too much?\n\nFor context: this is part of a larger function that computes something, but does so in different ways depending on the setting of a mode parameter. I want to be able to pass in that mode parameter without evaluation; hence the original question. But I also want to be able to invoke the function inside a Table function as above. Here's a simple example:\n\nClear[\"Global*\"]\nSetAttributes[foo,HoldAll];\nfoo[x_] := Block[{z=ToString[Unevaluated[x]]}, If[x == \"square\", x^2, x+1]];\nTable[Integrate[foo[Evaluate[i]],{x,0,3}],{i,{\"square\", \"xyzzy\"}}];\n{9, 45/2}\na=3\nTable[Integrate[foo[Evaluate[i]],{x,0,3}],{i,{\"square\", \"xyzzy\"}}];\n{45/2, 45/2}\n\n\nsince in the second invocation the parameter to foo has the value 3, not the value a. How can I achieve both of these behaviors?\n\n• – rm -rf Jun 23 '12 at 17:12\n\nThis seems to work:\n\nSetAttributes[f, HoldAll];\nf[x_] := Print[ToString[Unevaluated[x]]]\n\n\nNow, try Middle = 3; f[Middle].\n\n• I was aboooout to post the same. +1 – Rojo Jun 23 '12 at 17:04\n• That should work fine. Thank you. – rogerl Jun 23 '12 at 17:28\n\nYou may want to use the attribute HoldAllComplete to avoid the Orderless property of Times, allowing multiple-word strings:\n\nSetAttributes[func, HoldAllComplete]\nfunc[stuff___] := ToString[Unevaluated[stuff]]\n\nfunc[this is a string without quotes]\n\n\"this is a string without quotes\"\n\n\nLower level syntax rules are still parsed however, so this is only safe with alphanumeric words:\n\nfunc[this is @ a @ string // without quotes]\n\n\"(without quotes)[this is[a[string]]]\"\n\n\nRegarding your updated question you should almost certainly be using indexed variables (DownValues). See this answer for reference.\n\na = 3\n\nTable[foo[Evaluate[i]], {i,{a,b,c}}] (* prints {3,b,c} *)\n\n\nCannot work, as a evaluates to 3 before Table assigns it to i (using a mechanism similar to Block). Consider:\n\na := Print[\"!\"]\n\nTable[Abort[], {i, {a, b, c}}]\n\nDuring evaluation of In[]:= !\n\nOut[]= \\$Aborted\n\n\nAs you can see the Print evaluates before the body.\n\nIf you have advance knowledge of the symbol names you could use Block (but IMHO this entire process is inadvisable):\n\nBlock[{a},\nTable[ToString[i], {i, {a, b, c}}]\n]\n`"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.83758503,"math_prob":0.91701734,"size":2110,"snap":"2019-43-2019-47","text_gpt3_token_len":586,"char_repetition_ratio":0.106362775,"word_repetition_ratio":0.031446543,"special_character_ratio":0.292891,"punctuation_ratio":0.1822034,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.97209865,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-11-22T22:35:15Z\",\"WARC-Record-ID\":\"<urn:uuid:a5771731-1094-4f72-ad09-b10f663399b9>\",\"Content-Length\":\"149098\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e04047d2-4851-4424-9a03-70f96f4ccc6c>\",\"WARC-Concurrent-To\":\"<urn:uuid:3fbef2e2-8a8a-47e1-ab17-add1b5522554>\",\"WARC-IP-Address\":\"151.101.1.69\",\"WARC-Target-URI\":\"https://mathematica.stackexchange.com/questions/7363/passing-unquoted-strings-poor-mans-enumeration?noredirect=1\",\"WARC-Payload-Digest\":\"sha1:MDU7BYVYFO656YDJFGQ2WKGNCF6Q4RN4\",\"WARC-Block-Digest\":\"sha1:JB2ZBVUEQKL6WWOPJAH5XHN4IFFXQETQ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-47/CC-MAIN-2019-47_segments_1573496672170.93_warc_CC-MAIN-20191122222322-20191123011322-00004.warc.gz\"}"} |
https://mathematica.stackexchange.com/questions/43135/how-to-define-an-n-variate-empirical-distribution-function-probability-for-any-n | [
"# How to define an n-variate empirical distribution function probability for any n?\n\nI'm using Mathematica 9.0 to calculate the probability according to the empirical distribution function (EDF) of some sample data. Afterwords this is included in a maximization stage so I define this probability as a function. I have to do apply this to groups of data in which each group has different dimensionality. Therefore I'd like to define a generic version of \"probability given by an EDF\" that I can apply to any of these groups.\n\nHere there is a toy example for some 2-dimensional samples:\n\ndata = Transpose[{{1, 3, 4, 9, 8, 7, 8}, {2, 1, 1, 6, 7, 8, 9}}];\nMatrixForm[data]\n\n\nIts EDF is simply:\n\nedf := EmpiricalDistribution[data];\n\n\nThen by hand one can easily define its probability function:\n\n edfProbFunction[t1_, t2_] := NProbability[x1 <= t1 \\[And] x2 <= t2, {x1, x2} \\[Distributed] edf];\n\n\nand compute the probability by just defining:\n\nedfProb[w1_, w2_] := Evaluate[edfProbFunction[w1, w2]];\n\n\nIn this way, given a new point (2,4) from this distribution, it has probability 0.142857 given by:\n\nedfProb[2,4]\n\n\nMy question is how to define a function like edfProbFunction for any dimension, not a fixed dimension (2 in the example)?\n\nI tried to do it in different ways but didn't succeed. I lack background in Mathematica so these attempts may be nonesense. I summarize them anyway in case this can be of any help:\n\nFirst naive attempt -- use a vector of input variables, straightforward\n\nedfProbFunction[t__] := NProbability[x <= t, x \\[Distributed] edf];\nedfProb[w__] := Evaluate[edfProbFunction[w]];\n\n\nUsing this definition of edfProb together with the edfProbFunction defined in the toy example works, but not with this edfProbFunction here. This made me think that I had to somehow made explicit each of the individual predicates (the inequalities) in edfProbFunction\n\nSecond attempt -- use MakeBoxes\n\nBut a simple example shows that the expressions produced by this are not seen as variables in edfProbFunction:\n\nxP /: MakeBoxes[xP[x___], form_] := RowBox[Riffle[Map[MakeBoxes[#, form] &, {x}], \",\"]]\nx = \"\" <> {\"x\", IntegerString};\nx = \"\" <> {\"x\", IntegerString};\nvarx = xP[x,x] (*this produces a list x1,x2 *)\nedfProbFunction[t1_,t2_] := NProbability[x1 <= t1 \\[And] x2 <= t2, {varx} \\[Distributed] edf];\n\n\nThird attempt -- I tried to define a function that recursively creates the predicate, but it doesn't work neither:\n\ntable = Table[x[i] <= t[i], {i, 2}];\ng[n_] := If[Length[n] > 1, n[] \\[And] g[Drop[n, 1]], If[Length[n] == 1, n[], 0]]\npredicate = g[table]\nedfProbFunction[t_] := NProbability[predicate, {t, t} \\[Distributed] edf];\nedfProb[w__] := Evaluate[edfProbFunction[w]];\nedfProb[{2, 4}]\n\n\nAny suggestions will be welcome, specially complete answers to my question.\n\nThe biggest issue in trying to put this together is that NProbability mixed with EmpiricalDistribution doesn't seem to like array indexed variables. Building up symbols programatically seems to fix the issue.\n\nedfP[data_?MatrixQ][t__?NumericQ] /;\nLength[{t}] == Length[data[]] := Block[{vars, x},\nvars = Table[Symbol[\"x\" <> ToString[i]], {i, Length[{t}]}];\nNProbability @@ {And @@ Thread[vars <= {t}],\nvars \\[Distributed] EmpiricalDistribution[data]}\n]\n\n\nFirst lets verify it works for your example...\n\nedfProb[3, 4]\n(* 0.285714 *)\n\nedfP[data][3, 4]\n(* 0.285714 *)\n\n\nAnd now to generalize...\n\nedfP[RandomVariate[NormalDistribution[], {10^4, 4}]][-1, 1, 2, 1]\n\n(* 0.1061 *)\n\n\nNote that if you are going to run this repeatedly for the same data you should evaluate the empirical distribution outside and pass that in rather than the data itself.\n\nEDIT:\n\nNow all that said, this seems like overkill to me. If I understand your question correctly why can't you just use CDF?\n\nSeedRandom;\ndat = RandomVariate[NormalDistribution[], {10^4, 4}];\n\nedfP[dat][-1, 1, 2, 1]\n(* 0.1143 *)\n\nCDF[EmpiricalDistribution@dat, {-1, 1, 2, 1}]\n(* 0.1143 *)\n\n• Both your approaches work really fine, they answer my question. So why can't I just use CDF? Well, I couldn't because I didn't even know this simple way, but now I can. Thanks a lot! – p-d Mar 6 '14 at 17:11"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.80761254,"math_prob":0.97326845,"size":2701,"snap":"2020-45-2020-50","text_gpt3_token_len":779,"char_repetition_ratio":0.14942528,"word_repetition_ratio":0.024449877,"special_character_ratio":0.29877824,"punctuation_ratio":0.17300381,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9972464,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-10-23T21:34:19Z\",\"WARC-Record-ID\":\"<urn:uuid:73e0054b-b1ac-4d97-bae2-bb5a0f8cd0fe>\",\"Content-Length\":\"152513\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e21bffac-4bc3-468e-9c2a-ca54e17a859e>\",\"WARC-Concurrent-To\":\"<urn:uuid:0c5fa633-63f9-4bac-8e91-628231ed48c5>\",\"WARC-IP-Address\":\"151.101.193.69\",\"WARC-Target-URI\":\"https://mathematica.stackexchange.com/questions/43135/how-to-define-an-n-variate-empirical-distribution-function-probability-for-any-n\",\"WARC-Payload-Digest\":\"sha1:ODVYBHEGXPSJMZ6ODRGH2Q6IN6WZBDTF\",\"WARC-Block-Digest\":\"sha1:3HECNQ4XWIMDID6URVGR2X46VFMVG4PA\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-45/CC-MAIN-2020-45_segments_1603107865665.7_warc_CC-MAIN-20201023204939-20201023234939-00423.warc.gz\"}"} |
https://learn.careers360.com/ncert/question-construct-the-following-angles-and-verify-by-measuring-them-by-a-protractor-i-75-degrees/ | [
"# Q4. Construct the following angles and verify by measuring them by a protractor: (i) 75o\n\nD Divya Prakash Singh\n\nSteps to construction to follow:",
null,
"Step 1: Draw a ray OY.\n\nStep 2: Now, taking O as the centre draw an arc ABC.\n\nStep 3: On taking A as a centre, draw two arcs B and C on the arc ABC.\n\nStep 4: Now, taking B and C as centres, arcs are made to intersect at point E and the is constructed.\n\nStep 5: Taking A and C as centres, arcs are made to intersect at D.\n\nStep 6: Now, join OD and hence, is constructed.\n\nHence, is the required angle.\n\nExams\nArticles\nQuestions"
] | [
null,
"https://d2pduerm2meudp.cloudfront.net/media/uploads/2019/07/02/construction8.PNG",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.95430833,"math_prob":0.7159169,"size":970,"snap":"2020-10-2020-16","text_gpt3_token_len":271,"char_repetition_ratio":0.1594203,"word_repetition_ratio":0.88324875,"special_character_ratio":0.27113402,"punctuation_ratio":0.18623482,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.97651845,"pos_list":[0,1,2],"im_url_duplicate_count":[null,4,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-03-29T06:52:49Z\",\"WARC-Record-ID\":\"<urn:uuid:e9214c87-37e7-4158-82d0-f0f49b978469>\",\"Content-Length\":\"760807\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:01fcea09-c068-4920-bbdd-c2f5df9b46d2>\",\"WARC-Concurrent-To\":\"<urn:uuid:1626fb79-a1f6-40a7-a75d-3ed15c700609>\",\"WARC-IP-Address\":\"13.127.75.213\",\"WARC-Target-URI\":\"https://learn.careers360.com/ncert/question-construct-the-following-angles-and-verify-by-measuring-them-by-a-protractor-i-75-degrees/\",\"WARC-Payload-Digest\":\"sha1:6QVAJNJJ6XH57AOR3MYCUHJUCMTYEYGM\",\"WARC-Block-Digest\":\"sha1:RLBXVMBAP5DDLLUN6JV4WBWWKIAXALCQ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-16/CC-MAIN-2020-16_segments_1585370493818.32_warc_CC-MAIN-20200329045008-20200329075008-00202.warc.gz\"}"} |
https://stage.geogebra.org/m/eb98jrA4 | [
"# MULTIPLE CHOICE QUESTIONS- CLASS XI\n\nSelect all that apply\n• A\n• B\n• C\n• D\n\nThe complex conjucate of 2+i is\n\nSelect all that apply\n• A\n• B\n• C\n• D\n\n(1) The Order of the matrix [1 2 5 7] is\n\nSelect all that apply\n• A\n• B\n• C\n• D\n\n(2) Number of elements in a matrix or order 2 x 3 is\n\nSelect all that apply\n• A\n• B\n• C\n• D\n\n(3) if A =\n\nSelect all that apply\n• A"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.70179814,"math_prob":0.85418826,"size":362,"snap":"2022-40-2023-06","text_gpt3_token_len":138,"char_repetition_ratio":0.12849163,"word_repetition_ratio":0.7407407,"special_character_ratio":0.36187845,"punctuation_ratio":0.03529412,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.965138,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-02-02T12:05:15Z\",\"WARC-Record-ID\":\"<urn:uuid:ad6b3d5d-9294-4e79-ac3f-c49033aa6c73>\",\"Content-Length\":\"59824\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:082d959a-3a40-4d6e-a509-a9202df97e93>\",\"WARC-Concurrent-To\":\"<urn:uuid:eb193067-09e0-443e-8bc8-8c96c253bf9c>\",\"WARC-IP-Address\":\"18.67.76.62\",\"WARC-Target-URI\":\"https://stage.geogebra.org/m/eb98jrA4\",\"WARC-Payload-Digest\":\"sha1:IZR6NLH4GRMFVAQA2JOT2PR7XEFGG2VS\",\"WARC-Block-Digest\":\"sha1:XQVLPN4HNONTASHXKTUKKQF3DHNXDZ3M\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-06/CC-MAIN-2023-06_segments_1674764500017.27_warc_CC-MAIN-20230202101933-20230202131933-00448.warc.gz\"}"} |
https://www.foresttrailacademy.com/sixth-grade-mathematics-curriculum.html | [
"Call 800.890.6269 / 561.537.5501\nOffice Hours 9AM - 6PM Mon-Fri,12PM - 4PM Sat",
null,
"# Grade 6 Mathematics Course Outline\n\nTo satisfy the Common Core Standards for 6th grade mathematics this course focuses on four critical areas.\n\nFirst, students will learn to connect the ideas of ratio and rate to multiplication and division. If they can view ratios and rates as originating from and extending pairs of rows or columns the connection with multiplication and division allows students to expand on their skills.\n\nSecond, the students will complete their understanding of the division of fractions and of the system of rational numbers, including negative numbers. They will understand the order and absolute value of rational numbers and the location of points on the four quadrants of the coordinate plane.\n\nThird, the students will learn to write and understand expressions and equations. The students will become able to write equations and expressions that describe a given situation. They understand that the solutions of an equation are the variables that make the equation true. The students learn to solve simple one-step equations and can create tables to describe the relationships between values.\n\nFourth, the students will begin to develop an understanding of statistics. They will understand that data distribution may not have a definite center and that different methods of measurement can provide different values. The students will learn how to use and calculate the mean and median of a group of numbers. They learn how the measurement of variability helps to describe a set of data.\n\n1- Introduction\n\n• Introduction\n• Course Description\n• Pretest\n• Assignment: Pretest\n• MLA Formatting MSWord 2007\n• MLA Citation\n• MLA Incorporating Sources\n\n2- Number Sense\n\n• Problem Solving\n• Handout: Problem-Solving Worksheet\n• Handout: Problem-Solving Graphic Organizer\n• Assignment: Problem-Solving\n• Assignment: Problem-Solving Graphic Organizer\n• Exponents\n• Assignment: Exponents\n• Squares & Square Roots\n• Worksheet: Squares & Square Roots\n• Order of Operations\n• Handout: Order of Operations KWL Chart\n• Handout: Order of Operations Worksheet\n• Assignment: Order of Operations KWL Chart\n• Assignment: Order of Operations\n• Absolute Value\n• Handout: Absolute Value Worksheeet\n• Quiz: Absolute Value\n• Assignment: Absolute Value\n• Compare & Order Integers\n• Worksheet: Compare & Order Integers\n• Worksheet: Adding & Subtracting Integers\n• Multiplying & Dividing Integers\n• Worksheet: Multiplying & Dividing Integers\n\n3- Decimals\n\n• Compare & Order Decimals\n• Worksheet: Compare & Order Decimals\n• Estimation with Decimals\n• Handout: Estimation with Decimals Worksheet\n• Assignment: Estimation with Decimals\n• Assignment: Subtracting Decimals\n• Multiplying Decimals\n• Assignment: Multiplying Decimals\n• Dividing Decimals\n• Quiz: Dividing Decimals\n• Handout: Birthday Party Problem\n• Assignment: Birthday Party Problem\n\n4- Introduction to Fractions\n\n• Factors\n• Quiz: Factors\n• Prime Factorization\n• Handout: Prime Factorization Worksheet\n• Assignment: Prime Factorization\n• Greatest Common Factor\n• Worksheet: Greatest Common Factors\n• Fractions\n• Handout: Fraction Maze\n• Quiz: Name That Fraction!\n• Assignment: Fraction Maze\n• Worksheet: Mixed Numbers & Improper Fractions\n• Quiz: Equivalent Fractions\n• Simplifying Fractions\n• Worksheet: Simplifying Fractions\n• Convert Fractions to Decimals\n• Handout: Fractions to Decimals\n• Assignment: Fractions to Decimals\n• Estimation with Fractions\n• Handout: Estimation with Fractions Worksheet\n• Assignment: Estimation with Fractions\n\n5- Operations With Fractions\n\n• Add & Subtract Fractions, Part 1\n• Handout: Add & Subtract Fractions, Part 1 Worksheet\n• Assignment: Add & Subtract Fractions, Part 1\n• Least Common Multiple\n• Worksheet: Least Common Multiple\n• Add & Subtract Fractions, Part 2\n• Handout: Add & Subtract Fractions, Part 2 Worksheet\n• Assignment: Add & Subtract Fractions, Part 2\n• Add & Subtract Mixed Numbers\n• Handout: Adding Mixed Numbers Worksheet\n• Handout: Subtracting Mixed Numbers Worksheet\n• Assignment: Subtracting Mixed Numbers\n• Multiplying Fractions\n• Handout: Multiply Fractions Worksheet\n• Assignment: Multiply Fractions\n• Assignment: A Fraction of a Recipe\n• Dividing Fractions\n• Handout: Dividing Fractions Worksheet\n• Assignment: Dividing Fractions\n\n6- Algebra\n\n• Properties\n• Essay: Properties\n• Quiz: Properties\n• Expressions\n• Handout: Expressions Worksheet\n• Assignment: Expressions\n• Introduction to Equations\n• Worksheet: Equations\n• Writing Equations\n• Handout: Writing Equations Worksheet\n• Assignment: Writing Equations\n• Solving Equations: Addition & Subtraction\n• Worksheet: Equations With Addition & Subtraction\n• Solving Equations: Multiplication\n• Handout: Equation Chain Worksheet\n• Worksheet: Equations With Multiplication\n• Assignment: Equation Chains\n• Midtest\n• Assignment: Midtest\n\n7- Ratios & Proportions\n\n• Ratios\n• Handout: Writing Ratios Worksheet\n• Worksheet: Simplifying Ratios\n• Quiz: Equivalent Ratios\n• Assignment: Writing Ratios\n• Rates\n• Worksheet: Rates\n• Proportions\n• Handout: Solving Proportions Worksheet\n• Worksheet: Proportions\n• Assignment: Solving Proportions\n• Measurement: The Metric System\n• Worksheet: Metric System\n• Measurement: Customary Units\n• Worksheet: Customary Units\n• Measurement: Conversions\n• Worksheet: Conversions\n\n8- Percents\n\n• Percent\n• Handout: Finding Percents Worksheet\n• Assignment: Finding Percents\n• Quiz: Percents\n• Fractions, Decimals &Percents\n• Handout: Exploring Fractions, Decimals, Percents Worksheet\n• Assignment: Exploring Fractions, Decimals, Percents\n• Worksheet: Fractions, Decimals, Percents\n• Percent of a Number\n• Worksheet: Percent of a Number\n• Estimation with Percent\n• Worksheet: Estimation with Percent\n• Compare & Order Fractions, Decimals &Percents\n• Handout: Compare & Order FDP Worksheet\n• Assignment: Compare & Order FDP\n\n9- Geometry\n\n• Angles\n• Handout: Angles Worksheet\n• Quiz: Complimentary, Supplementary or Neither\n• Assignment: Angles\n• Polygons\n• Assignment: Polygon Art Project\n• Triangles\n• Handout: Triangles Graphic Organizer\n• Assignment: Triangles\n• Assignment: Triangles Graphic Organizer\n• Circles\n• Assignment: Parts of a Circle\n• Worksheet: Diameter and Radius Worksheet\n• Perimeter\n• Handout: Perimeter Worksheet\n• Assignment: Perimeter\n• Coordinate Geometry\n• Handout: Art in the Coordinate Plane\n• Handout: Coordinate Plane Worksheet\n• Assignment: Art in the Coordinate Plane\n• Assignment: Coordinate Plane\n\n10- Area & Volume\n\n• Area: Parallelograms\n• Handout: Area of Parallelograms Worksheet\n• Assignment: Area of Parallelograms\n• Area: Triangles & Trapezoids\n• Handout: Area of Triangles & Trapezoids Worksheet\n• Assignment: Area of Triangles & Trapezoids\n• Three-Dimensional Solids\n• Handout: 3D Solids Worksheet\n• Assignment: 3D Solids\n• Nets & Surface Area\n• Worksheet: Surface Area of Cubes\n• Worksheet: Surface Area of Rectangular Prisms\n• Volume: Prisms\n• Handout: Volume of Prisms Worksheet\n• Assignment: Volume of Prisms\n• Volume: Pyramids\n• Handout: Volume of Pyramids Worksheet\n• Assignment: Volume of Pyramids\n\n11- Statistics\n\n• Measures of Central Tendency\n• Handout: Measures of Central Tendency Worksheet\n• Assignment: Measures of Central Tendency\n• Line Plots\n• Assignment: Line Plots\n• Stem and Leaf Plots\n• Assignment: Stem & Leaf Plots\n• Bar Graphs\n• Assignment: Bar Graphs\n• Circle Graphs\n• Assignment: Circle Graphs\n• Using Graphs to Predict\n• Assignment: Using Graphs to Predict\n• Using Data to Predict\n• Assignment: Using Data to Predict\n• Using Sampling to Predict\n• Assignment: Using Sampling to Predict\n• Post-test\n• Assignment: Post-test\n• Handout: Statistics Project Rubric\n• Handout: Statistics Project Outline\n• Assignment: Statistics Project\n\n12- Course Survey\n\n• Handout: Course Survey\n• Assignment: Course Survey\nForest Trail Academy Accreditation and Memberships\nWhat Student say",
null,
"Forest Trail Academy is the BEST school ever, the staff is amazing!! I recently graduated from Forest Trail Academy after going there for 2 years. I went to public school…\nDemi Arthur",
null,
"FTA was a great alternative option for me so far as high school went. i transferred out during my junior year after having a rough time in public high school…\nSarah Kosar",
null,
"Katie Bowcutt wins title ex-aequo, PKRA Jr World Champion, 2013Freestyle Kiteboarding.Thanks for your support, Forest Trail Academy…\nKatie Bowcutt",
null,
"Thank you Forest Trail Academy for helping my student excel! Placing my high school freshman in your program was the best choice! He works through the program at his pace…\nAllison H.",
null,
"FTA has been a blessing to me!! I didn’t fit in at my old school, i had trouble learning in such a disruptive classroom which meant my grades falling, coming…\nYasmen Wass",
null,
"Hello my name is Brittany Wooten. I graduated from forest trail academy in 2009. I decided to choose fta because I wanted to accelerate my high school education. Fta was …\nBrittany Wooten",
null,
"FTA gave me HOPE. I don’t have the pressures of exams and trying to keep up with the rest of the class. I get to go over the work as…\nJoshua Lawrence",
null,
"Forest Trail Academy has been a blessing to me. I compete in the sport of rodeo across many states, and it takes time and dedication to train and condition both …\nAudrey Barnett",
null,
"The last two years of high school couldn’t be described in one word. Forest Trail Academy is definitely a school that looks for excellence in their students, and endorses rigorous …\nBen Lively\nFind The Right Program for You"
] | [
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/05/search_placeholder_text.gif",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/demi_author_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/sarah_kosar_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/katie_bowcutt_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/Allison_Hernandez_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/yasmen_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/brittany_wooten_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/joshua_lawrence_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/audrey_testimonial.jpg",
null,
"https://www.foresttrailacademy.com/wp-content/uploads/2018/04/Ben_Lively_testimonial.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.91581666,"math_prob":0.63443637,"size":1580,"snap":"2019-43-2019-47","text_gpt3_token_len":301,"char_repetition_ratio":0.15291879,"word_repetition_ratio":0.0,"special_character_ratio":0.18860759,"punctuation_ratio":0.063432835,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99664676,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-11-22T13:49:43Z\",\"WARC-Record-ID\":\"<urn:uuid:e78f15da-b22e-425b-8c33-efaafd49c602>\",\"Content-Length\":\"118276\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:50684b06-ae5e-4c85-af0e-8d6f9efcaa79>\",\"WARC-Concurrent-To\":\"<urn:uuid:7b87c625-55bc-4db3-ab6b-3ecc258f7036>\",\"WARC-IP-Address\":\"74.115.208.28\",\"WARC-Target-URI\":\"https://www.foresttrailacademy.com/sixth-grade-mathematics-curriculum.html\",\"WARC-Payload-Digest\":\"sha1:66MTVTA2F6ETCLPQNZKPPJSJKDJH6F4J\",\"WARC-Block-Digest\":\"sha1:2QIUIET2GXC2EHM35AWPWXIKTWMI2LJ6\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-47/CC-MAIN-2019-47_segments_1573496671260.30_warc_CC-MAIN-20191122115908-20191122143908-00184.warc.gz\"}"} |
https://phys.libretexts.org/Bookshelves/College_Physics/Book%3A_College_Physics_(OpenStax)/33%3A_Particle_Physics/33.02%3A_The_Yukawa_Particle_and_the_Heisenberg_Uncertainty_Principle_Revisited | [
"$$\\require{cancel}$$\n\n# 33.2: The Yukawa Particle and the Heisenberg Uncertainty Principle Revisited\n\n•",
null,
"• Contributed by OpenStax\n• General Physics at OpenStax CNX\n\nParticle physics as we know it today began with the ideas of Hideki Yukawa in 1935. Physicists had long been concerned with how forces are transmitted, finding the concept of fields, such as electric and magnetic fields to be very useful. A field surrounds an object and carries the force exerted by the object through space. Yukawa was interested in the strong nuclear force in particular and found an ingenious way to explain its short range. His idea is a blend of particles, forces, relativity, and quantum mechanics that is applicable to all forces. Yukawa proposed that force is transmitted by the exchange of particles (called carrier particles). The field consists of these carrier particles.",
null,
"Figure $$\\PageIndex{1}$$: The strong nuclear force is transmitted between a proton and neutron by the creation and exchange of a pion. The pion is created through a temporary violation of conservation of mass-energy and travels from the proton to the neutron and is recaptured. It is not directly observable and is called a virtual particle. Note that the proton and neutron change identity in the process. The range of the force is limited by the fact that the pion can only exist for the short time allowed by the Heisenberg uncertainty principle. Yukawa used the finite range of the strong nuclear force to estimate the mass of the pion; the shorter the range, the larger the mass of the carrier particle.\n\nSpecifically for the strong nuclear force, Yukawa proposed that a previously unknown particle, now called a pion, is exchanged between nucleons, transmitting the force between them. Figure $$\\PageIndex{1}$$ illustrates how a pion would carry a force between a proton and a neutron. The pion has mass and can only be created by violating the conservation of mass-energy. This is allowed by the Heisenberg uncertainty principle if it occurs for a sufficiently short period of time. As discussed in Probability: The Heisenberg Uncertainty Principle the Heisenberg uncertainty principle relates the uncertainties $$ΔE$$ in energy and $$Δt$$ in time by\n\n$ΔEΔt≥\\frac{h}{4π}$\n\nwhere $$h$$ is Planck’s constant. Therefore, conservation of mass-energy can be violated by an amount $$ΔE$$ for a time $$Δt≈\\frac{h}{4πΔE}$$ in which time no process can detect the violation. This allows the temporary creation of a particle of mass m, where $$ΔE=mc^2$$. The larger the mass and the greater the $$ΔE$$, the shorter is the time it can exist. This means the range of the force is limited, because the particle can only travel a limited distance in a finite amount of time. In fact, the maximum distance is $$d≈cΔt$$, where $$c$$ is the speed of light. The pion must then be captured and, thus, cannot be directly observed because that would amount to a permanent violation of mass-energy conservation. Such particles (like the pion above) are called virtual particles, because they cannot be directly observed but their effects can be directly observed. Realizing all this, Yukawa used the information on the range of the strong nuclear force to estimate the mass of the pion, the particle that carries it. The steps of his reasoning are approximately retraced in the following worked example:\n\nExample $$\\PageIndex{1}$$: Calculating the Mass of a Pion\n\nTaking the range of the strong nuclear force to be about 1 fermi ($$10^{−15}$$m), calculate the approximate mass of the pion carrying the force, assuming it moves at nearly the speed of light.\n\nStrategy\n\nThe calculation is approximate because of the assumptions made about the range of the force and the speed of the pion, but also because a more accurate calculation would require the sophisticated mathematics of quantum mechanics. Here, we use the Heisenberg uncertainty principle in the simple form stated above, as developed in Probability: The Heisenberg Uncertainty Principle. First, we must calculate the time $$Δt$$ that the pion exists, given that the distance it travels at nearly the speed of light is about 1 fermi. Then, the Heisenberg uncertainty principle can be solved for the energy $$ΔE$$, and from that the mass of the pion can be determined. We will use the units of $$MeV/c^2$$ for mass, which are convenient since we are often considering converting mass to energy and vice versa.\n\nSolution\n\nThe distance the pion travels is $$d≈cΔt$$, and so the time during which it exists is approximately\n\n$Δt≈\\frac{d}{c}=\\dfrac{10^{−15}m}{3.0×10^8m/s}≈3.3×10^{−24}s. \\nonumber$\n\nNow, solving the Heisenberg uncertainty principle for $$ΔE$$ gives\n\n$ΔE≈\\frac{h}{4πΔt}≈\\dfrac{6.63×10^{−34}J⋅s}{4π(3.3×10^{−24}s)}. \\nonumber$\n\nSolving this and converting the energy to MeV gives\n\n$ΔE≈(1.6×10^{−11}J)\\frac{1MeV}{1.6×10^{−13}J}=100\\,MeV. \\nonumber$\n\nMass is related to energy by $$ΔE=mc^2$$, so that the mass of the pion is $$m=ΔE/c^2$$, or\n\n$m≈100MeV/c^2. \\nonumber$\n\nDiscussion\n\nThis is about 200 times the mass of an electron and about one-tenth the mass of a nucleon. No such particles were known at the time Yukawa made his bold proposal.\n\nYukawa’s proposal of particle exchange as the method of force transfer is intriguing. But how can we verify his proposal if we cannot observe the virtual pion directly? If sufficient energy is in a nucleus, it would be possible to free the pion—that is, to create its mass from external energy input. This can be accomplished by collisions of energetic particles with nuclei, but energies greater than 100 MeV are required to conserve both energy and momentum. In 1947, pions were observed in cosmic-ray experiments, which were designed to supply a small flux of high-energy protons that may collide with nuclei. Soon afterward, accelerators of sufficient energy were creating pions in the laboratory under controlled conditions. Three pions were discovered, two with charge and one neutral, and given the symbols $$π^+$$,$$π^−$$, and $$π^0$$, respectively. The masses of $$π^+$$ and $$π^−$$ are identical at $$139.6\\, MeV/c^2$$, whereas $$π^0$$ has a mass of $$135.0MeV/c^2$$. These masses are close to the predicted value of $$100\\,MeV/c^2$$ and, since they are intermediate between electron and nucleon masses, the particles are given the name meson (now an entire class of particles, as we shall see in Particles, Patterns, and Conservation Laws).\n\nThe pions, or $$π^-$$mesons as they are also called, have masses close to those predicted and feel the strong nuclear force. Another previously unknown particle, now called the muon, was discovered during cosmic-ray experiments in 1936 (one of its discoverers, Seth Neddermeyer, also originated the idea of implosion for plutonium bombs). Since the mass of a muon is around $$106\\, MeV/c^2$$, at first it was thought to be the particle predicted by Yukawa. But it was soon realized that muons do not feel the strong nuclear force and could not be Yukawa’s particle. Their role was unknown, causing the respected physicist I. I. Rabi to comment, “Who ordered that?” This remains a valid question today. We have discovered hundreds of subatomic particles; the roles of some are only partially understood. But there are various patterns and relations to forces that have led to profound insights into nature’s secrets.\n\n## Summary\n\n• Yukawa’s idea of virtual particle exchange as the carrier of forces is crucial, with virtual particles being formed in temporary violation of the conservation of mass-energy as allowed by the Heisenberg uncertainty principle.\n\n## Glossary\n\npion\nparticle exchanged between nucleons, transmitting the force between them\nvirtual particles\nparticles which cannot be directly observed but their effects can be directly observed\nmeson\nparticle whose mass is intermediate between the electron and nucleon masses\n\n# Contributors\n\n• Paul Peter Urone (Professor Emeritus at California State University, Sacramento) and Roger Hinrichs (State University of New York, College at Oswego) with Contributing Authors: Kim Dirks (University of Auckland) and Manjula Sharma (University of Sydney). This work is licensed by OpenStax University Physics under a Creative Commons Attribution License (by 4.0)."
] | [
null,
"https://biz.libretexts.org/@api/deki/files/5084/girl-160172__340.png",
null,
"https://phys.libretexts.org/@api/deki/files/11146/Figure_34_01_01.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9342929,"math_prob":0.98240143,"size":8150,"snap":"2019-51-2020-05","text_gpt3_token_len":1947,"char_repetition_ratio":0.13454457,"word_repetition_ratio":0.04570528,"special_character_ratio":0.22932516,"punctuation_ratio":0.09762533,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99772096,"pos_list":[0,1,2,3,4],"im_url_duplicate_count":[null,null,null,5,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-01-23T05:32:17Z\",\"WARC-Record-ID\":\"<urn:uuid:3dadc126-107e-424a-ac5e-20e9b86f7d82>\",\"Content-Length\":\"93231\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:a4b11a31-2e93-4255-b06d-33197fe93b5d>\",\"WARC-Concurrent-To\":\"<urn:uuid:7914ab21-28fd-4140-ba62-1021449cf06c>\",\"WARC-IP-Address\":\"13.249.44.99\",\"WARC-Target-URI\":\"https://phys.libretexts.org/Bookshelves/College_Physics/Book%3A_College_Physics_(OpenStax)/33%3A_Particle_Physics/33.02%3A_The_Yukawa_Particle_and_the_Heisenberg_Uncertainty_Principle_Revisited\",\"WARC-Payload-Digest\":\"sha1:Q7YO5ZDG6Z3U4VAVW5YDCQFUS6OEDPPJ\",\"WARC-Block-Digest\":\"sha1:25AFJ3TSBZC55QRDYXXTC32PDFZSBZLZ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-05/CC-MAIN-2020-05_segments_1579250608295.52_warc_CC-MAIN-20200123041345-20200123070345-00393.warc.gz\"}"} |
https://stats.stackexchange.com/questions/239810/can-relative-risk-mislead-us-when-choosing-predictors-for-a-logistic-model | [
"# Can Relative Risk mislead us when choosing predictors for a logistic model?\n\nMy friend taught me to use Relative Risk as a guide to check if my coefficients make sense. For example, I have a propensity to default model, where the variable fl_default is equal to 1 if the individual defaulted and equal to zero if he didn't default. I also have the region where individuals belong: A, B, C, D and E - and other variables. In the figure below, I have the number of people that defaulted in each region and their relative risk, and what I understand is that people in region A, B and D are good customers, they have more propensity to pay.",
null,
"However, if I run a logistic regression and the coefficient for the predictor REGION is the opposite of this Relative Risk, should I treat this variable (make some modification) or it is possible that the coefficient gives a different direction than the relative risk? What could be happening with my model?\n\n• A more straightforward diagnostic for the sign of the model coefficient is to compare it to the sign of a pairwise, spearman correlation. If they aren't the same, then that can suggest an underlying issue with collinearity. Oct 12, 2016 at 15:46\n\nA relative risk compares two groups so in your situation you could compare the risk of defaulting in group A versus group D. The risk in group A is $\\frac{86}{86 + 179}$ and in group D is $\\frac{240}{240 + 268}$. The risk ratio is thus the ratio of these two quantities $$\\frac{\\frac{86}{86 + 179}}{\\frac{240}{240 + 268}}$$ If when you work them out correctly you still get an issue then perhaps better to post a new question."
] | [
null,
"https://i.stack.imgur.com/mOFdh.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9330463,"math_prob":0.9583922,"size":867,"snap":"2023-40-2023-50","text_gpt3_token_len":180,"char_repetition_ratio":0.11819235,"word_repetition_ratio":0.0,"special_character_ratio":0.20761245,"punctuation_ratio":0.10344828,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9923816,"pos_list":[0,1,2],"im_url_duplicate_count":[null,3,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-09-28T10:44:05Z\",\"WARC-Record-ID\":\"<urn:uuid:9fe320c4-f55a-4794-ae52-4edb5e39f2ba>\",\"Content-Length\":\"157108\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:c6c4a85a-a03a-4f8e-bd5b-3911564747b2>\",\"WARC-Concurrent-To\":\"<urn:uuid:02379613-917d-4f31-8390-74f803ff4f87>\",\"WARC-IP-Address\":\"104.18.10.86\",\"WARC-Target-URI\":\"https://stats.stackexchange.com/questions/239810/can-relative-risk-mislead-us-when-choosing-predictors-for-a-logistic-model\",\"WARC-Payload-Digest\":\"sha1:NJGAAFSU5VDNOY3KCGL4IACJBOOYLYYV\",\"WARC-Block-Digest\":\"sha1:DAJKLXIKXK44QL7LDLBQHLFMV3CMD2CO\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-40/CC-MAIN-2023-40_segments_1695233510387.77_warc_CC-MAIN-20230928095004-20230928125004-00771.warc.gz\"}"} |
https://math.stackexchange.com/questions/2761682/max-the-entropy | [
"# Max the entropy\n\nI have a simple optimization problem, but somewhere I am making a mistake. I want to maximize the entropy for the four $p_1, p_2, p_3, p_4$. I want to use Lagrange multiplier with constraints. Thus:\n\n$\\sum_i p_i \\log_2(p_i)$ for $i$ of the interval $[1,4]$\ns.t.\n$g(p_1,p_2,p_3,p_4) = p_1+p_2+p_3+p_4 = 1$ .\n\nNow I want to compute it with Lagrange multiplier: $$L(p_1,p_2,p_3,p_4,\\lambda)= -p_1 \\log p_1 - p_2 \\log p_2 - p_3 \\log p_3 - p_4 \\log p_4- \\lambda(p_1 + p_2 + p_3 + p_4 - 1)$$ If I compute the partial derivatives:\n$$\\frac{\\partial L}{\\partial p_i} = -\\log p_i - 1 - \\lambda= 0$$ Thus:\n$$p_i = - e - e^{\\lambda}$$ If I now insert it in the Lagrange function $L$:\n$$L(p_1,p_2,p_3,p_4,\\lambda)= -p_1 \\log p_1 - p_2 \\log p_2 - p_3 \\log p_3 - p_4 \\log p_4- \\lambda(p_1 + p_2 + p_3 + p_4 - 1)$$ I will have negative values in the log:\n$$-(- e - e^{\\lambda} \\log(-e-e^{\\lambda}))$$ which is not solvable.\nI don't know where my mistake is.\n\n• Note that it makes no sense to use Lagrange multipliers for this, because $p$ isn't differentiable (it's non-zero only at four points!). I've asked this question in the past and will link to it. – Clarinetist May 1 '18 at 11:45\n• @Clarinetist This problem is defined on a finite set with cardinality 4, not the same as your problem :) – Xiangxiang Xu May 1 '18 at 12:07\n\nSince $\\frac{\\partial L}{\\partial p_i} = -\\log p_i - 1 - \\lambda = 0$, we have $$p_i = \\mathrm{e}^{-\\lambda - 1}.$$ As a result, $$p_1 = p_2 = p_3 = p_4 = \\frac{1}{4},$$"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.59852016,"math_prob":0.9998316,"size":939,"snap":"2019-51-2020-05","text_gpt3_token_len":391,"char_repetition_ratio":0.14010695,"word_repetition_ratio":0.25609756,"special_character_ratio":0.45260915,"punctuation_ratio":0.14851485,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99999046,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-12-07T04:21:55Z\",\"WARC-Record-ID\":\"<urn:uuid:ae491a1f-5bdb-44d3-b226-e0cb6a676a8a>\",\"Content-Length\":\"133705\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:b11e4c38-d6e8-48c9-8cf0-6a3cf1ad1e2c>\",\"WARC-Concurrent-To\":\"<urn:uuid:49be83e9-f8e8-447c-a102-3e00663d2107>\",\"WARC-IP-Address\":\"151.101.129.69\",\"WARC-Target-URI\":\"https://math.stackexchange.com/questions/2761682/max-the-entropy\",\"WARC-Payload-Digest\":\"sha1:D3TEWJ5RXIYTR7M3EBD5ILXOR2ZDMXXZ\",\"WARC-Block-Digest\":\"sha1:5SPC7ED75KGV46EQGOCNOMELFLOBBJBR\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-51/CC-MAIN-2019-51_segments_1575540495263.57_warc_CC-MAIN-20191207032404-20191207060404-00324.warc.gz\"}"} |
https://www.cryptoground.com/digix-dao-profit-calculator | [
"• Market Cap: \\$266b\n\n• Apr 04, 2020\n\nDigix DAO Profit Calculator or you can say Digix DAO ROI Calculator is a simple tool to calculate how much profit you would have made if you had invested in Digix DAO (DGD) in past. This helps you measure the return on investment (ROI) of Digix DAO (DGD) .\n\nIf you are looking for mining calc check it here: Digix DAO Mining Calculator\n\nWhat my profit would be If I have invested\n\\$\nin Digix DAO on the date\n?\n\n## How does Digix DAO Profit Calculator Works?\n\nThis Digix DAO Profit Calculator uses a simple mathematical principal to calculate the ROI of Digix DAO. It fetches the historical Digix DAO price from the database and compares with current Digix DAO Price and calculate the profit or loss made on it.\n\nIt does this simple calculation get the amount Digix DAO you would have got by investing x\\$'s on that day (\\$x/price of Digix DAO). Now it calculates the current price of that amount in USD (current Digix DAO price * amount of Digix DAO purchased in past). Now the return on investment (ROI) is calculated by dividing amount in USD today by amount invested and multiplying it by 100.\n\nMathmetical logic behind the same:\n\n\\$invested_USD = USD invested in past date;\n\\$historical_DGD_price = Price of DGD in past date;\n\\$quantity_DGD = Quantity of DGD in past = \\$amount invested / \\$price_on_that_day;\n\\$price_DGD = Current price of DGD;\n\\$USD_today = (\\$price_DGD * \\$quantity_DGD) - \\$invested_USD;\n\\$ROI = (\\$USD_today/\\$invested_USD)*100;\n\nAnd if you want to check future price of Digix DAO you can check it here: Digix DAO Price Prediction. This predictions are based on various algorithms applied on the historical price of the Digix DAO.\n\nIf you have any query regarding the above calculator you can comment it in comment box below."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.88697153,"math_prob":0.94587845,"size":1316,"snap":"2020-10-2020-16","text_gpt3_token_len":308,"char_repetition_ratio":0.18064025,"word_repetition_ratio":0.0,"special_character_ratio":0.22492401,"punctuation_ratio":0.073913045,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9950469,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-04-04T23:22:09Z\",\"WARC-Record-ID\":\"<urn:uuid:d5a3a356-cdf4-4f48-b78f-5da4e8642467>\",\"Content-Length\":\"85876\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:cb4a6f15-d381-4c0e-99cc-4e0b539d573c>\",\"WARC-Concurrent-To\":\"<urn:uuid:ccd4bf2f-03fa-4bbf-953c-4a2bd04b9816>\",\"WARC-IP-Address\":\"159.65.47.196\",\"WARC-Target-URI\":\"https://www.cryptoground.com/digix-dao-profit-calculator\",\"WARC-Payload-Digest\":\"sha1:3OAHJQ76NIK2SWA5ELW7KQZDQKU6QMFZ\",\"WARC-Block-Digest\":\"sha1:VR4IXLJ5XZUTCRJ3GGEYPGQ623VQJHCX\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-16/CC-MAIN-2020-16_segments_1585370526982.53_warc_CC-MAIN-20200404231315-20200405021315-00151.warc.gz\"}"} |
https://www.engineeringcivil.com/mix-design-m-40-grade.html?replytocom=453907 | [
"Search\n\nPosted in Mix Design |",
null,
"Email This Post |\n\nThe mix design M-40 grade for Pier (Using Admixture – Fosroc) provided here is for reference purpose only. Actual site conditions vary and thus this should be adjusted as per the location and other factors.\n\nParameters for mix design M40\n\nType of cement = O.P.C-43 grade\nBrand of cement = Vikram ( Grasim )\nAdmixture = Fosroc ( Conplast SP 430 G8M )\nFine Aggregate = Zone-II\nSp. Gravity Cement = 3.15\nFine Aggregate = 2.61\nCoarse Aggregate (20mm) = 2.65\nCoarse Aggregate (10mm) = 2.66\nMinimum Cement (As per contract) = 400 kg / m3\nMaximum water cement ratio (As per contract) = 0.45\n\nMix Calculation: –\n\n1. Target Mean Strength = 40 + (5 X 1.65) = 48.25 Mpa\n\n2. Selection of water cement ratio:-\nAssume water cement ratio = 0.4\n\n3. Calculation of cement content: –\nAssume cement content 400 kg / m3\n(As per contract Minimum cement content 400 kg / m3)\n\n4. Calculation of water: –\n400 X 0.4 = 160 kg Which is less than 186 kg (As per Table No. 4, IS: 10262)\nHence o.k.\n\n5. Calculation for C.A. & F.A.: – As per IS : 10262 , Cl. No. 3.5.1\n\nV = [ W + (C/Sc) + (1/p) . (fa/Sfa) ] x (1/1000)\n\nV = [ W + (C/Sc) + {1/(1-p)} . (ca/Sca) ] x (1/1000)\n\nWhere\n\nV = absolute volume of fresh concrete, which is equal to gross volume (m3) minus the volume of entrapped air ,\n\nW = mass of water ( kg ) per m3 of concrete ,\n\nC = mass of cement ( kg ) per m3 of concrete ,\n\nSc = specific gravity of cement,\n\n(p) = Ratio of fine aggregate to total aggregate by absolute volume ,\n\n(fa) , (ca) = total mass of fine aggregate and coarse aggregate (kg) per m3 of\nConcrete respectively, and\n\nSfa , Sca = specific gravities of saturated surface dry fine aggregate and Coarse aggregate respectively.\n\nAs per Table No. 3 , IS-10262, for 20mm maximum size entrapped air is 2% .\n\nAssume F.A. by % of volume of total aggregate = 36.5 %\n\n0.98 = [ 160 + ( 400 / 3.15 ) + ( 1 / 0.365 ) ( Fa / 2.61 )] ( 1 /1000 )\n\n=> Fa = 660.2 kg\n\nSay Fa = 660 kg.\n\n0.98 = [ 160 + ( 400 / 3.15 ) + ( 1 / 0.635 ) ( Ca / 2.655 )] ( 1 /1000 )\n\n=> Ca = 1168.37 kg.\n\nSay Ca = 1168 kg.\n\nConsidering 20 mm : 10mm = 0.6 : 0.4\n\n20mm = 701 kg .\n10mm = 467 kg .\n\nHence Mix details per m3\n\nCement = 400 kg\nWater = 160 kg\nFine aggregate = 660 kg\nCoarse aggregate 20 mm = 701 kg\nCoarse aggregate 10 mm = 467 kg\nAdmixture = 0.6 % by weight of cement = 2.4 kg.\nRecron 3S = 900 gm\n\nWater: cement: F.A.: C.A. = 0.4: 1: 1.65: 2.92\n\nObservation: –\nA. Mix was cohesive and homogeneous.\nB. Slump = 110mm\nC. No. of cube casted = 12 Nos.\n7 days average compressive strength = 51.26 MPa.\n28 days average compressive strength = 62.96 MPa which is greater than 48.25MPa\n\nHence the mix is accepted.\n\nWe are thankful to Er Gurjeet Singh for this valuable information.\n\nMore Entries :\n• Mohan.g March 7, 2015 at 9:17 am\n\nI want to know m40 grade Ratio for making 80 mm concreate paver block , so please send me details.\n\n• AJAY April 4, 2015 at 3:11 am\n\nEXACT RATIO 1:1/5:3\n\n• S.M.Govardhan November 28, 2015 at 1:42 am\n\nsir, please specify the M 40 ratios approximately as per IS 10262:2009\n\n• jamil December 7, 2015 at 7:03 am\n\nHow Calculate by volume. Please send email thanks\n\n• MURUGAN.S January 2, 2016 at 2:20 am\n\ndear sir i want mauvel mix m40 grade of concrete in apartment building\n\n• PRAVEEN May 18, 2016 at 10:12 am\n\nsir iam planning to manufacture 80mm zig zag interlocking economy pavers to use in petrol pumps, with m40 strength,kindly suggest what is the ratio of cement:rock powder:6mm&8mm chips with how much hydraulic pressure is required. pl. suggest\n\n• Hansraj Pawar November 25, 2016 at 7:39 am\n\nHello Sir, Please specify mix design of M40 with Fly ash & use OPC 53 grade\n\n• Zeyauddin January 17, 2017 at 2:30 am\n\nHow to calculate mix design for interlock paving block M30?please explain me detail.send my mail\n\n• Azimkhan and shirish shah January 25, 2017 at 12:56 pm\n\ndear sir, how to design M:40 with cement 53 grade, crushed sand (different sieve no) and permissible admixture to pressure grout for micro piling.\n\n• Azimkhan and shirish shah January 25, 2017 at 1:11 pm\n\ndear sir, I want m:40 design with port land cement 53, crushed sand (sieve no.) and permissible admixture to be used by pressure grout for micro piling.\n\n• dheeraj kumar February 2, 2017 at 9:32 am\n\nPl send me M40 Grade of concrete cover block ratio\n\n• ??ng Khoa April 14, 2017 at 4:30 am\n\nDear sir,\nSir i have just started the manufacturing unit of paving blocks brick will you please send me the design for M15,M20, M25,M30,M35,M40 & M45 BY USING PCB40, Fly ash type F.\nThank you Sir\n\n• Sourav pal April 18, 2017 at 3:12 pm\n\nSir,\nI want to manufacture 60mm paver block.what will be the mix proportion of M30 by 6mm stone , sand and ppc 53grade cement and admixture\n\n• Vikram Singh yadav February 16, 2018 at 8:32 am\n\nDear sir\n\nI am starting a concrete interlocking block and fly ash brick can you send me the correct mix design with fly ash for m3 of semi dry mix for the above mentioned products.\ntype mixer in my factory\nRolling pan mixehar\nWarm Regards"
] | [
null,
"https://www.engineeringcivil.com/wp-content/plugins/wp-email/images/email.gif",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.81752014,"math_prob":0.97918606,"size":4490,"snap":"2020-10-2020-16","text_gpt3_token_len":1389,"char_repetition_ratio":0.111012034,"word_repetition_ratio":0.050113894,"special_character_ratio":0.3427617,"punctuation_ratio":0.14845361,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9682106,"pos_list":[0,1,2],"im_url_duplicate_count":[null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-02-16T21:35:50Z\",\"WARC-Record-ID\":\"<urn:uuid:570a7b33-897e-4457-98d8-e83c1f11ba1d>\",\"Content-Length\":\"49160\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:0edfef12-cd24-4e5d-be6f-610bcd1707a8>\",\"WARC-Concurrent-To\":\"<urn:uuid:62e460a8-2d53-41e2-8303-1e9351763d1b>\",\"WARC-IP-Address\":\"198.57.181.181\",\"WARC-Target-URI\":\"https://www.engineeringcivil.com/mix-design-m-40-grade.html?replytocom=453907\",\"WARC-Payload-Digest\":\"sha1:3LUIM3ZJU5YYRX3BJ6Z7TQ6LJGNJJU67\",\"WARC-Block-Digest\":\"sha1:2DMUIC7HSTISSOVWIF7A6XJUUSF3CTTW\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-10/CC-MAIN-2020-10_segments_1581875141430.58_warc_CC-MAIN-20200216211424-20200217001424-00026.warc.gz\"}"} |
https://in.mathworks.com/matlabcentral/profile/authors/6876387 | [
"Community Profile",
null,
"# Yarpiz\n\n##### Last seen: 6 months ago\n95 total contributions since 2015\n\nAbout the Yarpiz Project\nYarpiz is aimed to be a resource of academic and professional scientific source codes and tutorials, specially targeting the fields of Artificial Intelligence, Machine Learning, Engineering Optimization, Operational Research, and Control Engineering. Source codes provided in Yarpiz, are all free to use for research and academic purposes, and free to share and modify, as well. Projects are implemented in several programming languages, such as MATLAB, C#, Java, C++, Python and Visual Basic.\n\nWhat is the meaning of word Yarpiz?\nYarpiz (or alternatively Yarpuz) is an Azeri Turkish word, meaning Pennyroyal or Mentha Pulegium plant. Mostly it is used to make tea (hot drink), which is very good for treating colds and influenza.\n\nFor more information, visit Yarpiz website:\nwww.yarpiz.com\n\n#### Yarpiz's Badges\n\nView details...\n\nContributions in\nView by\n\nSubmitted\n\nYPEA\nYarpiz Evolutionary Algorithms Toolbox (YPEA) is a toolbox to solve optimization problems using Evolutionary Algorithms and Meta...\n\n6 months ago | 18 downloads |",
null,
"Submitted\n\nNSGA-III in MATLAB\nImplementation of Non-dominated Sorting Genetic Algorithm III in MATLAB\n\n6 months ago | 48 downloads |",
null,
"Submitted\n\nYarpiz Evolutionary Algorithms Toolbox (YPEA)\nA MATLAB Toolbox for Evolutionary Computation\n\n1 year ago | 35 downloads |",
null,
"Solved\n\nCreate a vector\nCreate a vector from 0 to n by intervals of 2.\n\n1 year ago\n\nSolved\n\nFlip the vector from right to left\nFlip the vector from right to left. Examples x=[1:5], then y=[5 4 3 2 1] x=[1 4 6], then y=[6 4 1]; Request not ...\n\n1 year ago\n\nSolved\n\nWhether the input is vector?\nGiven the input x, return 1 if x is vector or else 0.\n\n1 year ago\n\nSolved\n\nFind max\nFind the maximum value of a given vector or matrix.\n\n1 year ago\n\nSolved\n\nGet the length of a given vector\nGiven a vector x, the output y should equal the length of x.\n\n1 year ago\n\nSolved\n\nInner product of two vectors\nFind the inner product of two vectors.\n\n1 year ago\n\nSolved\n\nArrange Vector in descending order\nIf x=[0,3,4,2,1] then y=[4,3,2,1,0]\n\n1 year ago\n\nSolved\n\nFind the sum of all the numbers of the input vector\nFind the sum of all the numbers of the input vector x. Examples: Input x = [1 2 3 5] Output y is 11 Input x ...\n\n1 year ago\n\nSolved\n\nSelect every other element of a vector\nWrite a function which returns every other element of the vector passed in. That is, it returns the all odd-numbered elements, s...\n\n1 year ago\n\nSubmitted\n\nVideo Tutorial of Particle Swarm Optimization (PSO) in MATLAB\nIn this video tutorial, implementation of PSO in MATLAB is discussed in detail.\n\n5 years ago | 17 downloads |",
null,
"Submitted\n\nBiogeography-Based Optimization (BBO)\nA structured implementation of Biogeography-Based Optimization (BBO) in MATLAB\n\n5 years ago | 15 downloads |",
null,
"Submitted\n\nMulti-Objective Particle Swarm Optimization (MOPSO)\nA structure MATLAB implementation of MOPSO for Evolutionary Multi-Objective Optimization\n\n5 years ago | 44 downloads |",
null,
"Submitted\n\nLinear Discriminant Analysis (LDA) aka. Fisher Discriminant Analysis (FDA)\nImplemenatation of LDA in MATLAB for dimensionality reduction and linear feature extraction\n\n5 years ago | 38 downloads |",
null,
"Submitted\n\nCultural Algorithm (CA)\nA structured implemenattion of Cultural Algorithm (CA) in MATLAB for global optimization\n\n5 years ago | 4 downloads |",
null,
"Submitted\n\nReal-Coded Simulated Annealing (SA)\nA structured implemenattion of real-coded Simulated Annealing (SA) in MATLAB\n\n5 years ago | 15 downloads |",
null,
"Submitted\n\nIntelligent Color Reduction and Quantization using Clustering Methods in MATLAB\nColor Reduaction using k-Means Clustering, Fuzzy c-Means Clustering (FCM), and SOM Neural Network\n\n5 years ago | 6 downloads |",
null,
"Submitted\n\nMinimum Spanning Tree\nSolution of Minimum Spanning Tree using PSO, ICA and FA in MATLAB\n\n5 years ago | 4 downloads |",
null,
"Submitted\n\nPath Planning using PSO in MATLAB\nOptimal mobile robot path planning using Particle Swarm Optimization (PSO) in MATLAB\n\n5 years ago | 21 downloads |",
null,
"Submitted\n\nData Envelopment Analysis (DEA)\nImplemenattion of various Data Envelopment Analysis (DEA) approaches in MATLAB\n\n5 years ago | 3 downloads |",
null,
"Submitted\n\nEconomic Dispatching using PSO and Nested PSO in MATLAB\nApplication of PSO and Nested PSO to Economic Power Dispatching considering operational constraints\n\n5 years ago | 8 downloads |",
null,
"Submitted\n\nPortfolio Optimization using Classic and Intelligent Algorithms\nPortfolio Optimization using Classic Mathos, PSO, ICA, NSGA-II and SPEA2 in MATLAB\n\n5 years ago | 2 downloads |",
null,
"Submitted\n\nInventory Control using PSO in MATLAB\nOptimal Inventory Control using Particle Swarm Optimization (PSO) in MATLAB\n\n5 years ago | 2 downloads |",
null,
"Submitted\n\nHub Location Allocation Problem\nSolution of Hub Location Allocation Problem using Particle Swarm Optimization (PSO) in MATLAB\n\n5 years ago | 2 downloads |",
null,
"Submitted\n\nFacility Layout Design using PSO in MATLAB\nApplication of Particle Swarm Optimization to Facility Layout Design Problem in MATLAB\n\n5 years ago | 5 downloads |",
null,
"Answered\nGraph of routes in vrp tw problem\nThis FEX submission, contains the VRP routes graphing: http://www.mathworks.com/matlabcentral/fileexchange/53113-vehicle-rout...\n\n5 years ago | 0\n\nSubmitted\n\nVehicle Routing Problem (VRP) using Simulated Annealing (SA)\nSolving Capacitated VRP using Simulated Annealing (SA) in MATLAB\n\n5 years ago | 27 downloads |",
null,
"Submitted\n\nParallel Machine Scheduling using Simulated Annealing (SA)\nA structured MATLAB implementation of Simulated Annealing (SA) for Parallel Machine Scheduling\n\n5 years ago | 6 downloads |",
null,
"Load more"
] | [
null,
"https://in.mathworks.com/responsive_image/150/0/0/0/0/cache/matlabcentral/profiles/6876387.png",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/acf106b9-b6ff-4471-99af-667969c41f94/1b48c2cf-e581-4d4f-bb84-d8d3085e956b/images/primaryScreenShot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/7abf057d-afa5-4651-acf5-51d9847a11a8/54ead943-0f61-4452-a129-abd853107368/images/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/9a123834-88b0-4056-88ad-7e9120432bdd/692abd62-71b6-4e30-a5b9-c0d78c2f212d/images/screenshot.png",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/57286/versions/8/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/52901/versions/2/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/52870/versions/2/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53151/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53150/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53149/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53148/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53147/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53146/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53145/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53144/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53143/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53142/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53141/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53140/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53113/versions/1/screenshot.jpg",
null,
"https://in.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/53112/versions/1/screenshot.jpg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.70725965,"math_prob":0.48592204,"size":1762,"snap":"2021-21-2021-25","text_gpt3_token_len":447,"char_repetition_ratio":0.32593855,"word_repetition_ratio":0.38125,"special_character_ratio":0.25936437,"punctuation_ratio":0.08064516,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.95333177,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42],"im_url_duplicate_count":[null,1,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-06-13T11:58:18Z\",\"WARC-Record-ID\":\"<urn:uuid:15e45c43-8cac-4437-b207-0f4cfc19cfb2>\",\"Content-Length\":\"157258\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:c99f436e-67c1-4420-8425-f06bf8b3afd8>\",\"WARC-Concurrent-To\":\"<urn:uuid:d43259a2-ce77-43a0-9b7a-f9e87818534d>\",\"WARC-IP-Address\":\"23.220.132.54\",\"WARC-Target-URI\":\"https://in.mathworks.com/matlabcentral/profile/authors/6876387\",\"WARC-Payload-Digest\":\"sha1:FMKC3OCNC2SBUUDAGC5ERDUDL6LKOY3L\",\"WARC-Block-Digest\":\"sha1:J52XGY35CIR6NBZ4GDWJ2UVWZZ7N4CZI\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-25/CC-MAIN-2021-25_segments_1623487608702.10_warc_CC-MAIN-20210613100830-20210613130830-00162.warc.gz\"}"} |
https://pypi.org/project/django-estimators/ | [
"Skip to main content\n\nA django model to persist and track machine learning models\n\n## Project description",
null,
"",
null,
"",
null,
"## Django-Estimators\n\nTidy Persistence and Retrieval for Machine Learning\n\n### Intro\n\nDjango-Estimators helps persist and track machine learning models (aka estimators) and datasets.\n\nThis library provides a series of proxy objects that wrap common python machine learning objects and dataset objects. As a result, this library can be used to version, track progress and deploy models. It’s highly extensible and can be used with almost any python object (scikit-learn, numpy arrays, modules, methods).\n\nThis repo utilizes django as an ORM. If you’d like to work outside of django, try the sqlalchemy-based estimators library instead.\n\n### Installation\n\nDjango-estimators is on PyPI, so just run:\n\n```pip install django-estimators\n```\n\n### Quick start\n\n1. Add “estimators” to your INSTALLED_APPS django setting like this\n\n```INSTALLED_APPS = [\n...\n'estimators',\n]\n```\n\n2. To create the estimators table, run\n\n```python manage.py migrate\n```\n\n3. Run python manage.py shell and get create new models like so\n\n```from sklearn.ensemble import RandomForestClassifier\nrfc = RandomForestClassifier()\n\nfrom estimators.models import Estimator\nest = Estimator(estimator=rfc)\nest.description = 'a simple forest'\nest.save()\n```\n\n4. Retrieve your model, using the classic django orm, we can pull the last Estimator\n\n```est = Estimator.objects.last()\n# now use your estimator\nest.estimator.predict(X)\n```\n\n### Use Case: Retrieving Models/Estimators\n\nIf you aren’t sure if it exists, the recommended method is to use the get_or_create method\n\n```est = Estimator.objects.get_or_create(estimator=object)\n# or potentially update it with update_or_create\nest = Estimator.objects.update_or_create(estimator=object)\n```\n\nIf you already have the model, in this case of type object\n\n```est = Estimator.objects.filter(estimator=object).first()\n```\n\nIf you know the unique hash of the model\n\n```est = Estimator.objects.filter(object_hash='d9c9f286391652b89978a6961b52b674').first()\n```\n\n### Use Case: Persisting and Retrieving DataSets\n\nThe DataSet class functions just like the Estimator class. If you have a numpy matrix or a pandas dataframe, you can wrap it with a DataSet object\n\n```import numpy as np\nimport pandas as pd\n\ndf = pd.DataFrame(np.random.randint(0,10,(100,8)))\n\nfrom estimators.models import DataSet\n\nds = DataSet(data=df)\nds.save()\n```\n\nYou can pull that same DataSet object later with\n\n```ds = DataSet.objects.latest('create_date')\n```\n\nAnd if you already have the dataset\n\n```ds = DataSet.objects.filter(data=df).first()\n```\n\n### Use Case: Persisting Predictions and Results\n\nSometimes the most valuable part of a machine learning is the whole process. Using an Evaluator object, we can define the relationships between X_test, y_test and y_predicted ahead of time.\n\nThen we can evaluate the evaluation plan, which in turn calls the predict method on the estimator and then presists all the wrapped objects.\n\nHere’s a demo of using an Evaluator.\n\n```from sklearn.datasets import load_digits\nfrom sklearn.ensemble import RandomForestClassifier\n\ndigits = load_digits() # 1797 by 64\nX = digits.data\ny = digits.target\n\n# simple splitting for validation testing\nX_train, X_test = X[:1200], X[1200:]\ny_train, y_test = y[:1200], y[1200:]\n\nrfc = RandomForestClassifier()\nrfc.fit(X_train, y_train)\n```\n\nNow create your evaluation plan\n\n```from estimators.models import Evaluator\nplan = Evaluator(X_test=X_test, y_test=y_test, estimator=rfc)\n\nresult = plan.evaluate() # executes `predict` method on X_test\n```\n\nAnd you can view all the atributes on the evaluation result\n\n```result.estimator\nresult.X_test\nresult.y_test # optional, used with supervised classifiers\nresult.y_predicted\n```\n\n### Using with Jupyter Notebook (or without a django app)\n\nDjango-Estimators can run as a standalone django app.In order to have access to the django db, you’ll need to set up the environment variable to load up your django project. In ipython, by default you can set the environment variable DJANGO_SETTINGS_MODULE to estimators.template_settings like so\n\n```import os\nimport django\nos.environ['DJANGO_SETTINGS_MODULE'] = \"estimators.template_settings\"\ndjango.setup()\n```\n\nIf you’re creating a new database (by default it’s db.sqlite3). Therefore we need to run migrations, so in python\n\n```from django.core.management import call_command\ncall_command('migrate')\n```\n\nNow you can continue you as usual…\n\n```from estimators.models import Estimator\n```\n\nTo use your own custom settings, make a copy of the estimators.template_settings and edit the fields. Like above, run os.environ['DJANGO_SETTINGS_MODULE'] = \"custom_settings_file\" before running django.setup().\n\n### Development Installation\n\nTo install the latest version of django-estimators, clone the repo, change directory to the repo, and pip install it into your current virtual environment.:\n\n```\\$ git clone [email protected]:fridiculous/django-estimators.git\n\\$ cd django-estimators\n\\$ <activate your project’s virtual environment>\n(virtualenv) \\$ pip install -e . # the dot specifies for this current repo\n```\n\n## Release history Release notifications | RSS feed\n\nThis version",
null,
"0.2.1",
null,
"0.2.0",
null,
"0.1.0.dev0 pre-release\n\n## Download files\n\nDownload the file for your platform. If you're not sure which to choose, learn more about installing packages.\n\nFiles for django-estimators, version 0.2.1\nFilename, size File type Python version Upload date Hashes\nFilename, size django_estimators-0.2.1-py2.py3-none-any.whl (20.1 kB) File type Wheel Python version py2.py3 Upload date Hashes"
] | [
null,
"https://warehouse-camo.ingress.cmh1.psfhosted.org/e78d88f2770e6f2d190a8322953f305807f45444/68747470733a2f2f7472617669732d63692e6f72672f667269646963756c6f75732f646a616e676f2d657374696d61746f72732e7376673f6272616e63683d6d6173746572",
null,
"https://warehouse-camo.ingress.cmh1.psfhosted.org/f73d6802ab85428eb2c5e8a5fbd333783e405982/68747470733a2f2f636f766572616c6c732e696f2f7265706f732f6769746875622f667269646963756c6f75732f646a616e676f2d657374696d61746f72732f62616467652e7376673f6272616e63683d6d6173746572",
null,
"https://warehouse-camo.ingress.cmh1.psfhosted.org/e00b7a415e943a53f8e4b1d165242d37c002d330/68747470733a2f2f6c616e6473636170652e696f2f6769746875622f667269646963756c6f75732f646a616e676f2d657374696d61746f72732f6d61737465722f6c616e6473636170652e7376673f7374796c653d666c6174",
null,
"https://pypi.org/static/images/blue-cube.e6165d35.svg",
null,
"https://pypi.org/static/images/white-cube.8c3a6fe9.svg",
null,
"https://pypi.org/static/images/white-cube.8c3a6fe9.svg",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.57583827,"math_prob":0.57742983,"size":5567,"snap":"2021-04-2021-17","text_gpt3_token_len":1322,"char_repetition_ratio":0.13823476,"word_repetition_ratio":0.0055172415,"special_character_ratio":0.23387821,"punctuation_ratio":0.14644352,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9661746,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12],"im_url_duplicate_count":[null,3,null,3,null,3,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-04-20T03:46:09Z\",\"WARC-Record-ID\":\"<urn:uuid:4d4eaf93-edca-48b4-a80e-a0c9d6c17289>\",\"Content-Length\":\"59867\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:c6aecd24-66ad-4e75-9f05-0ce353fcf67e>\",\"WARC-Concurrent-To\":\"<urn:uuid:fa4f42b0-1e3b-4b4b-9fb3-03e0f88991ca>\",\"WARC-IP-Address\":\"151.101.64.223\",\"WARC-Target-URI\":\"https://pypi.org/project/django-estimators/\",\"WARC-Payload-Digest\":\"sha1:RPW4UXMSYO3IJ3P5IBW353GF6RRHY7KT\",\"WARC-Block-Digest\":\"sha1:G6L4OTHODBBF2ZMTTB3VFEZXTQ4BXRSG\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-17/CC-MAIN-2021-17_segments_1618039375537.73_warc_CC-MAIN-20210420025739-20210420055739-00327.warc.gz\"}"} |
https://stackovergo.com/es/q/5300485/multivariate-series-expansion-in-sympy | [
"# Expansión de series multivariadas en sympy\n\nDoes anyone know if there is a built-in function in sympy to obtain a multivariate series expansion of the form\n\n``````f(x,y) = a + b*x + c*y + d*x**2 + e*x*y + f*y**2 + ...\n``````\n\ni.e. by ascending order in all variables?\n\nGracias de antemano.\n\npreguntado el 09 de septiembre de 13 a las 23:09\n\nWhat do you start with (a polynomial, some other (analytic) function)? What kind of output do you expect? (A polynomial, a list of monomials, something different?) -\n\nHi Piotr, I am interested in power series expansions of any multivariate function, as a multivariate variant of \"series\": -\n\nI had meant to continue with an example: something like (exp(x)*exp(y)).series() giving 1 + x + y + x2/2 + x*y + y2/2 + ... -\n\n## 2 Respuestas\n\nIt is maybe too late but here is what I would do. It is not exactly a builtin function but it does the job. The idea is to introduce a temporary variable (eps) using substitutions and to expand the series over it. Here is an example:\n\n``````import sympy\nx, y , eps = sympy.symbols('x y eps')\nf = sympy.exp(x-y)\nf.subs(x,x*eps).subs(y,y*eps).series(eps).removeO().subs(eps,1)\n``````\n\nNote that using this technique you can have \"asymmetric\" expansions in x and y. For instance: `f.subs(x,x*eps).subs(y,y*eps**2)` ...\n\nRespondido el 04 de diciembre de 14 a las 13:12\n\nThe short answer is that currently (sympy build 0.7.5), there is no built-in function in sympy that will handle multivariate series expansions.\n\nThere appears to be support for series expansion of multivariate functions in . solo variables. You can see this in the docstring of `_eval_nseries` en el capítulo respecto a la `function` documentación aquí. If this is important to you, you can comment on the Rastreador de problemas o unirse a la lista de correo.\n\nSo, to be clear, this works:\n\n``````In : import sympy as sp\nIn : x, y = sp.symbols('x,y')\nIn : g = sp.exp(-x*y)\nIn : g\nOut: exp(-x*y)\nIn : g.series(x, 0)\nOut: 1 - x*y + x**2*y**2/2 - x**3*y**3/6 + x**4*y**4/24 - x**5*y**5/120 + O(x**6)\nIn : g.series(y, 0)\nOut: 1 - x*y + x**2*y**2/2 - x**3*y**3/6 + x**4*y**4/24 - x**5*y**5/120 + O(y**6)\n``````\n\nbut there is none of your desired functionality in any of the following:\n\n``````In : g.series((x, y), (0, 0))\nOut: exp(-x*y)\n\nIn : g.series((x, 0), (y, 0))\nOut: exp(-x*y)\n\nIn : g.series(x, 0, y, 0)\n---------------------------------------------------------------------------\nTypeError Traceback (most recent call last)\n<ipython-input-21-20c1ab732928> in <module>()\n----> 1 g.series(x, 0, y, 0)\n\n/usr/lib/python2.7/dist-packages/sympy/core/expr.pyc in series(self, x, x0, n, dir, logx)\n2401 return self\n2402\n-> 2403 if len(dir) != 1 or dir not in '+-':\n2404 raise ValueError(\"Dir must be '+' or '-'\")\n2405\n\nTypeError: object of type 'int' has no len()\n\nIn : g.series(x, y, 0, 0)\n---------------------------------------------------------------------------\nTypeError Traceback (most recent call last)\n<ipython-input-22-32b57736cd3d> in <module>()\n----> 1 g.series(x, y, 0, 0)\n\n/usr/lib/python2.7/dist-packages/sympy/core/expr.pyc in series(self, x, x0, n, dir, logx)\n2401 return self\n2402\n-> 2403 if len(dir) != 1 or dir not in '+-':\n2404 raise ValueError(\"Dir must be '+' or '-'\")\n2405\n\nTypeError: object of type 'int' has no len()\n``````\n\ncontestado el 12 de mayo de 14 a las 23:05\n\nNo es la respuesta que estás buscando? Examinar otras preguntas etiquetadas or haz tu propia pregunta."
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.5602107,"math_prob":0.8555611,"size":3326,"snap":"2022-40-2023-06","text_gpt3_token_len":1052,"char_repetition_ratio":0.14057797,"word_repetition_ratio":0.19157088,"special_character_ratio":0.38815394,"punctuation_ratio":0.16905071,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.983997,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2023-02-03T03:58:59Z\",\"WARC-Record-ID\":\"<urn:uuid:cfd71f5a-0948-4431-a76a-7eb529541bd3>\",\"Content-Length\":\"50152\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e620a57a-a639-4701-8b56-daf1f2e414e2>\",\"WARC-Concurrent-To\":\"<urn:uuid:f2bd919c-3447-4c41-b88b-dbd0453f0f04>\",\"WARC-IP-Address\":\"185.233.37.232\",\"WARC-Target-URI\":\"https://stackovergo.com/es/q/5300485/multivariate-series-expansion-in-sympy\",\"WARC-Payload-Digest\":\"sha1:MOVZX3N65WOO6KDYDT3I3A3SJHLFXS5B\",\"WARC-Block-Digest\":\"sha1:ERJHR7R4RIYCD7YTTFEOH55VYNQDHS23\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2023/CC-MAIN-2023-06/CC-MAIN-2023-06_segments_1674764500042.8_warc_CC-MAIN-20230203024018-20230203054018-00313.warc.gz\"}"} |
http://dizziness.academickids.com/encyclopedia/index.php/Pound-force | [
"# Pound-force\n\nThe pound-force is a non-SI unit of force or weight (properly abbreviated \"lbf\" or \"lbf\"). The pound-force is equal to a mass of one pound multiplied by the standard acceleration due to gravity on Earth (which is defined as exactly 9.806 65 m/s², or exactly 196,133/6096 ft/s², or approximately 32.174 05 ft/s²).\n\nThough pounds-force had been used in low-precision measurements since the 18th century, they were never well-defined units until the 20th century. It was in 1901 when the CGPM first adopted a standard acceleration of gravity for the purpose of defining grams-force and kilograms-force, a value often borrowed to define pounds-force, though other values such as 32.16 ft/s² (9.80237 m/s²) have been used as well.\n\nIn SI units, a pound-force is equal to exactly 4.448 221 615 260 5 newtons, if the metric standard acceleration of gravity is borrowed for this purpose.\n\nSee pound for a more complete discussion of customary units of force and mass.\n\n• Art and Cultures\n• Countries of the World (http://www.academickids.com/encyclopedia/index.php/Countries)\n• Space and Astronomy"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9225645,"math_prob":0.8557701,"size":989,"snap":"2020-34-2020-40","text_gpt3_token_len":246,"char_repetition_ratio":0.11878172,"word_repetition_ratio":0.0,"special_character_ratio":0.27098078,"punctuation_ratio":0.093596056,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98279095,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2020-08-09T06:35:27Z\",\"WARC-Record-ID\":\"<urn:uuid:a4b77612-6252-496c-96ca-7e385a9c4e87>\",\"Content-Length\":\"24771\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e8927069-c8f1-45ab-8db9-3189d7430963>\",\"WARC-Concurrent-To\":\"<urn:uuid:652a26d5-9103-425c-82fe-071910ded133>\",\"WARC-IP-Address\":\"108.59.0.28\",\"WARC-Target-URI\":\"http://dizziness.academickids.com/encyclopedia/index.php/Pound-force\",\"WARC-Payload-Digest\":\"sha1:KWWHX5ZITIOSLRW6A34CPP7CLSQI5BXL\",\"WARC-Block-Digest\":\"sha1:CTXRHHVOGJD3F3NHEPZ2QXYKYFVWJ57H\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2020/CC-MAIN-2020-34/CC-MAIN-2020-34_segments_1596439738425.43_warc_CC-MAIN-20200809043422-20200809073422-00148.warc.gz\"}"} |
https://sinovoltaics.com/learning-center/basics/short-circuit-current/ | [
"# Short Circuit Current\n\nShort circuit current is the current passing through a solar cell when voltage is zero across the solar cell, which happens when a solar cell is short circuited. Usually it is denoted Isc .\n\n#### How Isc is generated\n\nThe short circuit current results from collection and generation of light generated carriers. For a perfect solar cell with highly efficient loss mechanisms, both short circuit current and the light generated would both be matching. Consequently, the short circuit current is the greatest current that may be drawn out from the solar cell.\n\n#### Factors affecting Isc\n\nIt depends on a multiple factors as stated below:\n• The solar cell area: for removing the dependence of the solar cell area, it is typical to use the short circuit current density ,Jsc in units of mA/cm2 instead of the short-circuit current;\n• The photons number , which is describes the incident light source power. A solar cell’s Isc is directly proportional to the light intensity;\n• The incident light’s spectrum.\n• The absorption and reflection and other optical properties of the solar cell\n• The probability of collection of the solar cell, that mainly rely on the lifetime of minority carrier lifetime in the base and the surface passivation.\nFor comparison of solar cells having same type of material, the most important material factors are the surface passivation and diffusion length. In a cell that has a perfectly passivated surface and generation is uniform, the short circuit current equation can be approximately: ISC = qG (Ln + LP ) Where: G: the generation rate Ln and Lp: respectively the electron and hole diffusion lengths. Although several assumptions are made for this equation that are not necessarily true for the conditions in most solar cells, the equation above still show that the short circuit current strongly depend on and the diffusion length and the generation rate.Laboratory devices have measured short circuit currents for commercial solar cell in the range between 28 mA/cm2 and 35 mA/cm2. Illuminated Current and Short Circuit Current IL is the current generated from the light inside the solar cell and is the accurate term to use in solar cell equation. The externally measured current for short circuit current is Isc. As Isc is typically equal to IL, the two terms are interchangeably used and for easiness the solar cell equation uses Isc instead of IL. In case of really high series resistance ( greater than 10 Ωcm2) Isc is smaller than IL and the solar cell equation using Isc is incorrect. A different assumption is that the illumination current ( IL ) only depends on the incoming light and does not depend on the voltage across the cell. Yet, IL differs with voltage in the drift field solar cells case and when lifetime of carrier is a function of the injection level as in the case of defected multicrystalline materials.\nPlace comment\narrow_drop_up arrow_drop_down"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.919882,"math_prob":0.9652243,"size":2834,"snap":"2021-31-2021-39","text_gpt3_token_len":562,"char_repetition_ratio":0.19257951,"word_repetition_ratio":0.0,"special_character_ratio":0.18772054,"punctuation_ratio":0.07480315,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98683864,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2021-09-25T03:04:40Z\",\"WARC-Record-ID\":\"<urn:uuid:e124eaec-375e-4455-98ba-62edeb2a12bf>\",\"Content-Length\":\"37660\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:6817a279-4fc9-4440-ba6e-691e2e5a5e37>\",\"WARC-Concurrent-To\":\"<urn:uuid:4beef600-a6e8-4846-a016-f54c138b9dfc>\",\"WARC-IP-Address\":\"87.250.153.245\",\"WARC-Target-URI\":\"https://sinovoltaics.com/learning-center/basics/short-circuit-current/\",\"WARC-Payload-Digest\":\"sha1:3WYVINBZTJVMO2NAIYFVN5LQ33O5YQMC\",\"WARC-Block-Digest\":\"sha1:XRNIBGBKYSWCLDL2EYTWXA7TJT75APCL\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2021/CC-MAIN-2021-39/CC-MAIN-2021-39_segments_1631780057589.14_warc_CC-MAIN-20210925021713-20210925051713-00110.warc.gz\"}"} |
https://vitalik.ca/general/2017/11/09/starks_part_1.html | [
"Special thanks to Eli Ben-Sasson for ongoing help, explanations and review, coming up with some of the examples used in this post, and most crucially of all inventing a lot of this stuff; thanks to Hsiao-wei Wang for reviewing\n\nHopefully many people by now have heard of ZK-SNARKs, the general-purpose succinct zero knowledge proof technology that can be used for all sorts of usecases ranging from verifiable computation to privacy-preserving cryptocurrency. What you might not know is that ZK-SNARKs have a newer, shinier cousin: ZK-STARKs. With the T standing for “transparent”, ZK-STARKs resolve one of the primary weaknesses of ZK-SNARKs, its reliance on a “trusted setup”. They also come with much simpler cryptographic assumptions, avoiding the need for elliptic curves, pairings and the knowledge-of-exponent assumption and instead relying purely on hashes and information theory; this also means that they are secure even against attackers with quantum computers.\n\nHowever, this comes at a cost: the size of a proof goes up from 288 bytes to a few hundred kilobytes. Sometimes the cost will not be worth it, but at other times, particularly in the context of public blockchain applications where the need for trust minimization is high, it may well be. And if elliptic curves break or quantum computers do come around, it definitely will be.\n\nSo how does this other kind of zero knowledge proof work? First of all, let us review what a general-purpose succinct ZKP does. Suppose that you have a (public) function `f`, a (private) input `x` and a (public) output `y`. You want to prove that you know an `x` such that `f(x) = y`, without revealing what `x` is. Furthermore, for the proof to be succinct, you want it to be verifiable much more quickly than computing `f` itself.",
null,
"Let’s go through a few examples:\n\n• `f` is a computation that takes two weeks to run on a regular computer, but two hours on a data center. You send the data center the computation (ie. the code to run `f`), the data center runs it, and gives back the answer `y` with a proof. You verify the proof in a few milliseconds, and are convinced that `y` actually is the answer.\n• You have an encrypted transaction, of the form “X1 was my old balance. X2 was your old balance. X3 is my new balance. X4 is your new balance”. You want to create a proof that this transaction is valid (specifically, old and new balances are non-negative, and the decrease in my balance cancels out the increase in your balance). `x` can be the pair of encryption keys, and `f` can be a function which contains as a built-in public input the transaction, takes as input the keys, decrypts the transaction, performs the check, and returns 1 if it passes and 0 if it does not. `y` would of course be 1.\n• You have a blockchain like Ethereum, and you download the most recent block. You want a proof that this block is valid, and that this block is at the tip of a chain where every block in the chain is valid. You ask an existing full node to provide such a proof. `x` is the entire blockchain (yes, all ?? gigabytes of it), `f` is a function that processes it block by block, verifies the validity and outputs the hash of the last block, and `y` is the hash of the block you just downloaded.",
null,
"So what’s so hard about all this? As it turns out, the zero knowledge (ie. privacy) guarantee is (relatively!) easy to provide; there are a bunch of ways to convert any computation into an instance of something like the three color graph problem, where a three-coloring of the graph corresponds to a solution of the original problem, and then use a traditional zero knowledge proof protocol to prove that you have a valid graph coloring without revealing what it is. This excellent post by Matthew Green from 2014 describes this in some detail.\n\nThe much harder thing to provide is succinctness. Intuitively speaking, proving things about computation succinctly is hard because computation is incredibly fragile. If you have a long and complex computation, and you as an evil genie have the ability to flip a 0 to a 1 anywhere in the middle of the computation, then in many cases even one flipped bit will be enough to make the computation give a completely different result. Hence, it’s hard to see how you can do something like randomly sampling a computation trace in order to gauge its correctness, as it’s just to easy to miss that “one evil bit”. However, with some fancy math, it turns out that you can.\n\nThe general very high level intuition is that the protocols that accomplish this use similar math to what is used in erasure coding, which is frequently used to make data fault-tolerant. If you have a piece of data, and you encode the data as a line, then you can pick out four points on the line. Any two of those four points are enough to reconstruct the original line, and therefore also give you the other two points. Furthermore, if you make even the slightest change to the data, then it is guaranteed at least three of those four points. You can also encode the data as a degree-1,000,000 polynomial, and pick out 2,000,000 points on the polynomial; any 1,000,001 of those points will recover the original data and therefore the other points, and any deviation in the original data will change at least 1,000,000 points. The algorithms shown here will make heavy use of polynomials in this way for error amplification.",
null,
"Changing even one point in the original data will lead to large changes in a polynomial's trajectory\n\n### A Somewhat Simple Example\n\nSuppose that you want to prove that you have a polynomial `P` such that `P(x)` is an integer with `0 <= P(x) <= 9` for all `x` from 1 to 1 million. This is a simple instance of the fairly common task of “range checking”; you might imagine this kind of check being used to verify, for example, that a set of account balances is still positive after applying some set of transactions. If it were `1 <= P(x) <= 9`, this could be part of checking that the values form a correct Sudoku solution.\n\nThe “traditional” way to prove this would be to just show all 1,000,000 points, and verify it by checking the values. However, we want to see if we can make a proof that can be verified in less than 1,000,000 steps. Simply randomly checking evaluations of `P` won’t do; there’s always the possibility that a malicious prover came up with a `P` which satisfies the constraint in 999,999 places but does not satisfy it in the last one, and random sampling only a few values will almost always miss that value. So what can we do?",
null,
"Let’s mathematically transform the problem somewhat. Let `C(x)` be a constraint checking polynomial; `C(x) = 0` if `0 <= x <= 9` and is nonzero otherwise. There’s a simple way to construct `C(x)`: `x * (x-1) * (x-2) * ... * (x-9)` (we’ll assume all of our polynomials and other values use exclusively integers, so we don’t need to worry about numbers in between).",
null,
"Now, the problem becomes: prove that you know `P` such that `C(P(x)) = 0` for all `x` from 1 to 1,000,000. Let `Z(x) = (x-1) * (x-2) * ... (x-1000000)`. It’s a known mathematical fact that any polynomial which equals zero at all `x` from 1 to 1,000,000 is a multiple of `Z(x)`. Hence, the problem can now be transformed again: prove that you know `P` and `D` such that `C(P(x)) = Z(x) * D(x)` for all `x` (note that if you know a suitable `C(P(x))` then dividing it by `Z(x)` to compute `D(x)` is not too difficult; you can use long polynomial division or more realistically a faster algorithm based on FFTs). Now, we’ve converted our original statement into something that looks mathematically clean and possibly quite provable.\n\nSo how does one prove this claim? We can imagine the proof process as a three-step communication between a prover and a verifier: the prover sends some information, then the verifier sends some requests, then the prover sends some more information. First, the prover commits to (ie. makes a Merkle tree and sends the verifier the root hash of) the evaluations of `P(x)` and `D(x)` for all `x` from 1 to 1 billion (yes, billion). This includes the 1 million points where `0 <= P(x) <= 9` as well as the 999 million points where that (probably) is not the case.",
null,
"We assume the verifier already knows the evaluation of `Z(x)` at all of these points; the `Z(x)` is like a “public verification key” for this scheme that everyone must know ahead of time (clients that do not have the space to store `Z(x)` in its entirety can simply store the Merkle root of `Z(x)` and require the prover to also provide branches for every `Z(x)` value that the verifier needs to query; alternatively, there are some number fields over which `Z(x)` for certain `x` is very easy to calculate). After receiving the commitment (ie. Merkle root) the verifier then selects a random 16 `x` values between 1 and 1 billion, and asks the prover to provide the Merkle branches for `P(x)` and `D(x)` there. The prover provides these values, and the verifier checks that (i) the branches match the Merkle root that was provided earlier, and (ii) `C(P(x))` actually equals `Z(x) * D(x)` in all 16 cases.",
null,
"We know that this proof perfect completeness - if you actually know a suitable `P(x)`, then if you calculate `D(x)` and construct the proof correctly it will always pass all 16 checks. But what about soundness - that is, if a malicious prover provides a bad `P(x)`, what is the minimum probability that they will get caught? We can analyze as follows. Because `C(P(x))` is a degree-10 polynomial composed with a degree-1,000,000 polynomial, its degree will be at most 10,000,000. In general, we know that two different degree-N polynomials agree on at most N points; hence, a degree-10,000,000 polynomial which is not equal to any polynomial which always equals `Z(x) * D(x)` for some `x` will necessarily disagree with them all at at least 990,000,000 points. Hence, the probability that a bad `P(x)` will get caught in even one round is already 99%; with 16 checks, the probability of getting caught goes up to 1 - 10-32; that is to say, the scheme is about as hard to spoof as it is to compute a hash collision.\n\nSo… what did we just do? We used polynomials to “boost” the error in any bad solution, so that any incorrect solution to the original problem, which would have required a million checks to find directly, turns into a solution to the verification protocol that can get flagged as erroneous at 99% of the time with even a single check.\n\nWe can convert this three-step mechanism into a non-interactive proof, which can be broadcasted by a single prover once and then verified by anyone, using the Fiat-Shamir heuristic. The prover first builds up a Merkle tree of the `P(x)` and `D(x)` values, and computes the root hash of the tree. The root itself is then used as the source of entropy that determines what branches of the tree the prover needs to provide. The prover then broadcasts the Merkle root and the branches together as the proof. The computation is all done on the prover side; the process of computing the Merkle root from the data, and then using that to select the branches that get audited, effectively substitutes the need for an interactive verifier.\n\nThe only thing a malicious prover without a valid `P(x)` can do is try to make a valid proof over and over again until eventually they get extremely lucky with the branches that a Merkle root that they compute selects, but with a soundness of 1 - 10-32 (ie. probability of at least 1 - 10-32 that a given attempted fake proof will fail the check) it would take a malicious prover billions of years to make a passable proof.",
null,
"### Going Further\n\nTo illustrate the power of this technique, let’s use it to do something a little less trivial: prove that you know the millionth Fibonacci number. To accomplish this, we’ll prove that you have knowledge of a polynomial which represents a computation tape, with `P(x)` representing the x’th Fibonacci number. The constraint checking polynomial will now hop across three x-coordinates: `C(x1, x2, x3) = x3-x2-x1` (notice how if `C(P(x), P(x+1), P(x+2)) = 0` for all `x` then `P(x)` represents a Fibonacci sequence).",
null,
"The translated problem becomes: prove that you know `P` and `D` such that `C(P(x), P(x+1), P(x+2)) = Z(x) * D(x)`. For each of the 16 indices that the proof audits, the prover will need to provide Merkle branches for `P(x)`, `P(x+1)`, `P(x+2)` and `D(x)`. The prover will additionally need to provide Merkle branches to show that `P(0) = P(1) = 1`. Otherwise, the entire process is the same.\n\nNow, to accomplish this in reality there are two problems that need to be resolved. The first problem is that if we actually try to work with regular numbers the solution would not be efficient in practice, because the numbers themselves very easily get extremely large. The millionth Fibonacci number, for example, has 208988 digits. If we actually want to achieve succinctness in practice, instead of doing these polynomials with regular numbers, we need to use finite fields - number systems that still follow the same arithmetic laws we know and love, like `a * (b+c) = (a*b) + (a*c)` and `(a^2 - b^2) = (a-b) * (a+b)`, but where each number is guaranteed to take up a constant amount of space. Proving claims about the millionth Fibonacci number would then require a more complicated design that implements big-number arithmetic on top of this finite field math.\n\nThe simplest possible finite field is modular arithmetic; that is, replace every instance of `a + b` with `a + b mod N` for some prime N, do the same for subtraction and multiplication, and for division use modular inverses (eg. if `N = 7`, then `3 + 4 = 0`, `2 + 6 = 1`, `3 * 4 = 5`, `4 / 2 = 2` and `5 / 2 = 6`). You can learn more about these kinds of number systems from my description on prime fields here (search “prime field” in the page) or this Wikipedia article on modular arithmetic (the articles that you’ll find by searching directly for “finite fields” and “prime fields” unfortunately tend to be very complicated and go straight into abstract algebra, don’t bother with those).\n\nSecond, you might have noticed that in my above proof sketch for soundness I neglected to cover one kind of attack: what if, instead of a plausible degree-1,000,000 `P(x)` and degree-9,000,000 `D(x)`, the attacker commits to some values that are not on any such relatively-low-degree polynomial? Then, the argument that an invalid `C(P(x))` must differ from any valid `C(P(x))` on at least 990 million points does not apply, and so different and much more effective kinds of attacks are possible. For example, an attacker could generate a random value `p` for every `x`, then compute `d = C(p) / Z(x)` and commit to these values in place of `P(x)` and `D(x)`. These values would not be on any kind of low-degree polynomial, but they would pass the test.\n\nIt turns out that this possibility can be effectively defended against, though the tools for doing so are fairly complex, and so you can quite legitimately say that they make up the bulk of the mathematical innovation in STARKs. Also, the solution has a limitation: you can weed out commitments to data that are very far from any degree-1,000,000 polynomial (eg. you would need to change 20% of all the values to make it a degree-1,000,000 polynomial), but you cannot weed out commitments to data that only differ from a polynomial in only one or two coordinates. Hence, what these tools will provide is proof of proximity - proof that most of the points on P and D correspond to the right kind of polynomial.\n\nAs it turns out, this is sufficient to make a proof, though there are two “catches”. First, the verifier needs to check a few more indices to make up for the additional room for error that this limitation introduces. Second, if we are doing “boundary constraint checking” (eg. verifying `P(0) = P(1) = 1` in the Fibonacci example above), then we need to extend the proof of proximity to not only prove that most points are on the same polynomial, but also prove that those two specific points (or whatever other number of specific points you want to check) are on that polynomial.\n\nIn the next part of this series, I will describe the solution to proximity checking in much more detail, and in the third part I will describe how more complex constraint functions can be constructed to check not just Fibonacci numbers and ranges, but also arbitrary computation."
] | [
null,
"http://vitalik.ca/files/starks_pic1.png",
null,
"http://vitalik.ca/files/starks_pic2.png",
null,
"http://vitalik.ca/files/starks_pic_2p5.png",
null,
"http://vitalik.ca/files/starks_pic3.png",
null,
"http://vitalik.ca/files/starks_pic4.png",
null,
"http://vitalik.ca/files/starks_pic5.png",
null,
"http://vitalik.ca/files/starks_pic6.png",
null,
"http://vitalik.ca/files/starks_pic7.png",
null,
"http://vitalik.ca/files/starks_pic8.png",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.9220975,"math_prob":0.9700876,"size":16249,"snap":"2019-26-2019-30","text_gpt3_token_len":3828,"char_repetition_ratio":0.12877809,"word_repetition_ratio":0.016546018,"special_character_ratio":0.2385993,"punctuation_ratio":0.09678389,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9955958,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18],"im_url_duplicate_count":[null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null,2,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-07-21T09:36:38Z\",\"WARC-Record-ID\":\"<urn:uuid:4b13a093-c643-4903-a3d3-71c18f7f2cb3>\",\"Content-Length\":\"27748\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:3b704b66-1065-4e00-afed-fa313558191a>\",\"WARC-Concurrent-To\":\"<urn:uuid:6b5bf5b9-ec49-4f7f-b32c-d8830377e4db>\",\"WARC-IP-Address\":\"66.172.12.251\",\"WARC-Target-URI\":\"https://vitalik.ca/general/2017/11/09/starks_part_1.html\",\"WARC-Payload-Digest\":\"sha1:KYJYBXM7VM7AT6RGL5KTHKXLS27ZYAD2\",\"WARC-Block-Digest\":\"sha1:AKUSLZMGT3ANHBIEMFEOVXQIBPYKCDXQ\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-30/CC-MAIN-2019-30_segments_1563195526940.0_warc_CC-MAIN-20190721082354-20190721104354-00505.warc.gz\"}"} |
http://8foxes.blogspot.com/2010/03/fox-266.html?showComment=1269170320656 | [
"## Friday, March 19, 2010\n\n### Fox 266\n\nThis simple start will lead to a good one submitted by Lou.\n\n1.",
null,
"I tried finding a simplle plane geometry proof but failed to do so. While that elegant answer will come later, here's my trigonometric/analytical solution: If we assume B to be the origin and /_CBO=θ with AB=z then A:[zcos(60+θ),zsin(60+θ)] while C:[zcos(θ),zsin(θ)] and OC: y=x/√3 + z[sin(θ)-cos(θ)/√3) since slope of OC is tan(30) and it passes through C. This gives us O as [(zcos(θ)-√3zsin(θ)),0] and finally AO^2 = [zcos(θ)-√3zsin(θ)-zcos(60+θ)]^2+[zsin(θ)]^2 =z^2 on expansion and using [sin(θ)]^2 + [cos(θ)]^2 = 1 and thus AB = AO\nAjit\nPS: If you take a point P on AC such that /_PBC=(θ) and then prove that ABOP is concyclic then /_OBP=/_OAP=2θ from where it follows /_AOB =60+θ which makes triangle ABO isosceles. But as of now I can't prove that ABOP is concyclic.\n\n2.",
null,
"Joe, your solution is nice too. Although it is rigorous, it adds colors. We will post geometric solutions in the following days. Let's give a little more chance to others.\nThank you.\n\n3.",
null,
"How about this? With A as center draw a circle passing through A & B. Take any point Q in the larger sector BC. We know that /_BAC=60 deg. and hence /_BQC =30 deg. Thus for any point O on the smaller sector BC, /_BOC will always be 150 deg. since QBOC is concyclic. And for any such point O we always have AB = AO = radius of our circle.\nAjit\n\n4.",
null,
"Correction: With A as center draw a circle passing through thru. B & C\n\n5.",
null,
"Yep, that is the geometric solution we've received from at least two more visitors. There is one more geometric solution which was not found yet.\n\n6.",
null,
"See\n\nhttp://i40.tinypic.com/2wdyq28.png\n\nMIGUE.\n\n7.",
null,
"Correct Migue! There should be at least one more geometric solution, similar to yours."
] | [
null,
"http://lh3.googleusercontent.com/zFdxGE77vvD2w5xHy6jkVuElKv-U9_9qLkRYK8OnbDeJPtjSZ82UPq5w6hJ-SA=s35",
null,
"http://lh3.googleusercontent.com/zFdxGE77vvD2w5xHy6jkVuElKv-U9_9qLkRYK8OnbDeJPtjSZ82UPq5w6hJ-SA=s35",
null,
"http://lh3.googleusercontent.com/zFdxGE77vvD2w5xHy6jkVuElKv-U9_9qLkRYK8OnbDeJPtjSZ82UPq5w6hJ-SA=s35",
null,
"http://lh3.googleusercontent.com/zFdxGE77vvD2w5xHy6jkVuElKv-U9_9qLkRYK8OnbDeJPtjSZ82UPq5w6hJ-SA=s35",
null,
"http://lh3.googleusercontent.com/zFdxGE77vvD2w5xHy6jkVuElKv-U9_9qLkRYK8OnbDeJPtjSZ82UPq5w6hJ-SA=s35",
null,
"http://resources.blogblog.com/img/blank.gif",
null,
"http://lh3.googleusercontent.com/zFdxGE77vvD2w5xHy6jkVuElKv-U9_9qLkRYK8OnbDeJPtjSZ82UPq5w6hJ-SA=s35",
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.92524076,"math_prob":0.99074507,"size":3599,"snap":"2019-43-2019-47","text_gpt3_token_len":1096,"char_repetition_ratio":0.109040335,"word_repetition_ratio":0.8527919,"special_character_ratio":0.27590996,"punctuation_ratio":0.12787724,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.99835753,"pos_list":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14],"im_url_duplicate_count":[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-11-18T23:30:42Z\",\"WARC-Record-ID\":\"<urn:uuid:8ab65e54-6a3c-4201-900d-4b42e68ff11b>\",\"Content-Length\":\"102827\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:e1d01471-3e4b-4c29-8f75-d51f14595370>\",\"WARC-Concurrent-To\":\"<urn:uuid:28473c53-02e6-4b6f-81cb-9bf2e65ee060>\",\"WARC-IP-Address\":\"172.217.9.193\",\"WARC-Target-URI\":\"http://8foxes.blogspot.com/2010/03/fox-266.html?showComment=1269170320656\",\"WARC-Payload-Digest\":\"sha1:2RMXCMCNM5QUZ6PT643ZIYG6F3FTCCKG\",\"WARC-Block-Digest\":\"sha1:YM3DZURXKE5JQXO23WXE3PGHICSXKBXP\",\"WARC-Identified-Payload-Type\":\"application/xhtml+xml\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-47/CC-MAIN-2019-47_segments_1573496669868.3_warc_CC-MAIN-20191118232526-20191119020526-00129.warc.gz\"}"} |
https://www.tutorialspoint.com/explain-the-powershell-advanced-function | [
"# Explain the PowerShell Advanced Function.\n\nPowerShellMicrosoft TechnologiesSoftware & Coding\n\nBefore starting the Advance PowerShell function, assuming we know about the PowerShell function. You can check the explanation on the PowerShell function below.\n\nhttps://www.tutorialspoint.com/explain-the-powershell-function\n\nHere, we will take the math function example that calculates the different types of operations. We already have a code with the simple function as shown below.\n\nfunction math_Operation{\nparam([int]$val1,[int]$val2)\nWrite-Host \"Multiply : $($val1*$val2)\" Write-Host \"Addition :$($val1+$val2)\"\nWrite-Host \"Subtraction : $($val1-$val2)\" Write-Host \"Divide :$($val1+$val2)\"\n}\n\nThe above example is of the simple function. When you run the above code and run the function from the terminal and you can notice you will see only the $val1 and$val2 parameters while the PowerShell advanced function contains the additional common parameters like ErrorAction, WarningAction, Verbose, Passthru, etc.\n\nCheck the syntax below for the function when it is used as a simple function. No common parameters are added.\n\nPS C:\\WINDOWS\\system32> Get-Help math_Operation\nNAME\nmath_Operation\nSYNTAX\nmath_Operation [[-val1] <int>] [[-val2] <int>]\nALIASES\nNone\nREMARKS\nNone\n\nTo convert the simple function into the advanced function we just need to use the [cmdletbinding] into the function.\n\nfunction math_Operation{\n[cmdletbinding()]\nparam([int]$val1,[int]$val2)\nWrite-Host \"Multiply : $($val1*$val2)\" Write-Host \"Addition :$($val1+$val2)\"\nWrite-Host \"Subtraction : $($val1-$val2)\" Write-Host \"Divide :$($val1+$val2)\"\n}\n\nNow execute the above code and check the parameters, you can see the other parameters referred to as common parameters. Check the Syntax of this function after the execution of the code.\n\nPS C:\\WINDOWS\\system32> Get-Help math_Operation\nNAME\nmath_Operation\nSYNTAX\nmath_Operation [[-val1] <int>] [[-val2] <int>] [<CommonParameters>]\nALIASES\nNone\nREMARKS\nNone\n\nThis does not end here. PowerShell advanced function is more. So far we have converted the simple function into an advanced function. Let’s check the structure of the advanced function.\n\nfunction Verb-Noun {\n[CmdletBinding()]\nparam (\n// Parameters to declare with their datatypes\n)\nbegin {\n// Initialization of variables, create a log file\n}\nprocess {\n// Program code to make this function work\n}\nend {\n// Clearing values, log files, etc.\n}\n}\n\nIn the above function, you can see the PowerShell Advanced Function is mainly comprised of 3 blocks (Begin, Process, and End).\n\n• In the Begin block, you need to initialize the value of the variable or need to declare the log files, etc. This block executes first before the other two blocks and executes once only.\n\n• The Process block, where the actual code is executed and which uses the parameters declared in Param block and the values and log file path initialized in Begin block. This block runs for each item in the block.\n\n• The End block contains the values to be released/cleared from the variables and other cleanup tasks. This block also executes one time only after the process block executed.\n\nApart from the above functionalities, many other parameter attributes and arguments are supported which are explained in the next subsequent articles. Just have a glance at those parameter attributes and arguments.\n\n## Parameter Arguments\n\n• Mandatory\n\n• Parameter=0\n\n• ValueFromPipeline\n\n• ValueFromPipelineByPropertyName\n\n• ValueFromRemainingArguments\n\n• HelpMessage\n\n## Parameter Attributes\n\n• Param\n\n• Parameter\n\n• [AllowNull()]\n\n• [AllowEmptyString()]\n\n• [AllowEmptyCollection()]\n\n• [ValidateCount()]\n\n• [ValidateLength()]\n\n• [ValidatePattern()]\n\n• [ValidateRange()]\n\n• [ValidateScript()]\n\n• [ValidateSet()]\n\n• [ValidateNotNull()]\n\n• [ValidateNotNullOrEmpty()]\n\n• [DynamicParam]\n\n• [Switch]"
] | [
null
] | {"ft_lang_label":"__label__en","ft_lang_prob":0.62941843,"math_prob":0.9034512,"size":4796,"snap":"2022-05-2022-21","text_gpt3_token_len":1065,"char_repetition_ratio":0.16944908,"word_repetition_ratio":0.071428575,"special_character_ratio":0.22101751,"punctuation_ratio":0.09470752,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.98700017,"pos_list":[0],"im_url_duplicate_count":[null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2022-05-25T19:36:28Z\",\"WARC-Record-ID\":\"<urn:uuid:d98564b9-6a49-46bc-b593-65da3d50d804>\",\"Content-Length\":\"34154\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:17818ebe-635c-457f-abd7-c256a088f429>\",\"WARC-Concurrent-To\":\"<urn:uuid:a415a102-ec16-4592-b366-d932a990aa34>\",\"WARC-IP-Address\":\"192.229.210.176\",\"WARC-Target-URI\":\"https://www.tutorialspoint.com/explain-the-powershell-advanced-function\",\"WARC-Payload-Digest\":\"sha1:FVQSJBLECRM6UU36CIFEOBXNELQVRHFI\",\"WARC-Block-Digest\":\"sha1:BU6UFGWDXPIBSJ7LSVNSGC2S4T2T4SSB\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2022/CC-MAIN-2022-21/CC-MAIN-2022-21_segments_1652662593428.63_warc_CC-MAIN-20220525182604-20220525212604-00461.warc.gz\"}"} |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.