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Calculations of microscopic optical potentials (OP's) (their real and
imaginary parts) are performed to analyze the $^6$He+p elastic scattering data
at a few tens of MeV/nucleon (MeV/N). The OP's and the cross sections are
calculated using three model densities of $^6$He. Effects of the regularization
of the NN forces and their dependence on nuclear density are investigated.
Also, the role of the spin-orbit terms and of the non-linearity in the
calculations of the OP's, as well as effects of their renormalization are
studied. The sensitivity of the cross sections to the nuclear densities was
tested and one of them that gives a better agreement with the data was chosen.
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We consider self-stabilizing algorithms to compute a Maximal Independent Set
(MIS) in the extremely weak beeping communication model. The model consists of
an anonymous network with synchronous rounds. In each round, each vertex can
optionally transmit a signal to all its neighbors (beep). After the
transmission of a signal, each vertex can only differentiate between no signal
received, or at least one signal received. We assume that vertices have some
knowledge about the topology of the network.
We revisit the not self-stabilizing algorithm proposed by Jeavons, Scott, and
Xu (2013), which computes an MIS in the beeping model. We enhance this
algorithm to be self-stabilizing, and explore two different variants, which
differ in the knowledge about the topology available to the vertices. In the
first variant, every vertex knows an upper bound on the maximum degree $\Delta$
of the graph. For this case, we prove that the proposed self-stabilizing
version maintains the same run-time as the original algorithm, i.e. it
stabilizes after $O(\log n)$ rounds w.h.p. on any $n$-vertex graph. In the
second variant, each vertex only knows an upper bound on its own degree. For
this case, we prove that the algorithm stabilizes after $O(\log n\cdot \log
\log n)$ rounds on any $n$-vertex graph, w.h.p.
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Background: Immortal time is a period of follow-up during which death or the
study outcome cannot occur by design. Bias from immortal time has been
increasingly recognized in epidemiologic studies. However, the fundamental
causes and structures of bias from immortal time have not been explained
systematically using a structural approach. Methods: We use an example "Do
Nobel Prize winners live longer than less recognized scientists?" for
illustration. We illustrate how immortal time arises and present the structures
of bias from immortal time using time-varying directed acyclic graphs (DAGs).
We further explore the structures of bias with the exclusion of immortal time
and with the presence of competing risks. We discuss how these structures are
shared by different study designs in pharmacoepidemiology and provide
solutions, where possible, to address the bias. Results: We illustrate that
immortal time arises from using postbaseline information to define exposure or
eligibility. We use time-varying DAGs to explain the structures of bias from
immortal time are confounding by survival until exposure allocation or
selection bias from selecting on survival until eligibility. We explain that
excluding immortal time from the follow-up does not fully address this
confounding or selection bias, and that the presence of competing risks can
worsen the bias. Bias from immortal time may be avoided by aligning time zero,
exposure allocation and eligibility, and by excluding individuals with prior
exposure. Conclusions: Understanding bias from immortal time in terms of
confounding or selection bias helps researchers identify and thereby avoid or
ameliorate this bias.
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With the rapid development of future wireless communication, the combination
of NOMA technology and millimeter-wave(mmWave) technology has become a research
hotspot. The application of NOMA in mmWave heterogeneous networks can meet the
diverse needs of users in different applications and scenarios in future
communications. In this paper, we propose a machine learning framework to deal
with the user association, subchannel and power allocation problems in such a
complex scenario. We focus on maximizing the energy efficiency (EE) of the
system under the constraints of quality of service (QoS), interference
limitation, and power limitation. Specifically, user association is solved
through the Lagrange dual decomposition method, while semi-supervised learning
and deep neural network (DNN) are used for the subchannel and power allocation,
respectively. In particular, unlabeled samples are introduced to improve
approximation and generalization ability for subchannel allocation. The
simulation indicates that the proposed scheme can achieve higher EE with lower
complexity.
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A projective variety $X\subset\mathbb{P}^N$ is $h$-identifiable if the
generic element in its $h$-secant variety uniquely determines $h$ points on
$X$. In this paper we propose an entirely new approach to study
identifiability, connecting it to the notion of secant defect. In this way we
are able to improve all known bounds on identifiability. In particular we give
optimal bounds for some Segre and Segre-Veronese varieties and provide the
first identifiability statements for Grassmann varieties.
|
Unextendible product basis is an important object in quantum information
theory and features a broad spectrum of applications, ranging bound entangled
states, quantum nonlocality without entanglement, and Bell inequalities with no
quantum violation. A generalized concept called uncompletable product basis
also attracts much attention. In this paper, we find some unextendible product
bases that are uncompletable product bases in every bipartition, which answers
a 19 year-old open question proposed by DiVincenzo et al. [Commun. Math. Phys.
238, 379 (2003)]. As a consequence, we connect such unextendible product bases
to local hiding of information and give a sufficient condition for the
existence of an unextendible product basis, that is still an unextendible
product basis in every bipartition. Our results advance the understanding of
the geometry of unextendible product bases.
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We investigate a recombination-drift-diffusion model coupled to Poisson's
equation modelling the transport of charge within certain types of
semiconductors. In more detail, we study a two-level system for electrons and
holes endowed with an intermediate energy level for electrons occupying trapped
states. As our main result, we establish an explicit functional inequality
between relative entropy and entropy production, which leads to exponential
convergence to equilibrium. We stress that our approach is applied uniformly in
the lifetime of electrons on the trap level assuming that this lifetime is
sufficiently small.
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An open source software package for modelling thermal neutron transport is
presented. The code facilitates Monte Carlo-based transport simulations and
focuses in the initial release on interactions in both mosaic single crystals
as well as polycrystalline materials and powders. Both coherent elastic (Bragg
diffraction) and incoherent or inelastic (phonon) scattering are modelled,
using basic parameters of the crystal unit cell as input.
Included is a data library of validated crystal definitions, standalone tools
and interfaces for C++, C and Python programming languages. Interfaces for two
popular simulation packages, Geant4 and McStas, are provided, enabling highly
realistic simulations of typical components at neutron scattering instruments,
including beam filters, monochromators, analysers, samples and detectors. All
interfaces are presented in detail, along with the end-user configuration
procedure which is deliberately kept user-friendly and consistent across all
interfaces.
An overview of the relevant neutron scattering theory is provided, and the
physics modelling capabilities of the software are discussed. Particular
attention is given here to the ability to load crystal structures and form
factors from various sources of input, and the results are benchmarked and
validated against experimental data and existing crystallographic software.
Good agreements are observed.
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We explicitly obtain the $m$-soliton solutions of the (1+2)-dimensional
matrix Davey-Stewartson equation from the known general solution of the matrix
Toda chain with fixed ends. We write these solutions in terms of $m+m$
independent solutions of a pair of linear Shr\"odinger equations with Hermitian
potentials.
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We revisit constraints on dark photons with masses below ~ 100 MeV from the
observations of Supernova 1987A. If dark photons are produced in sufficient
quantity, they reduce the amount of energy emitted in the form of neutrinos, in
conflict with observations. For the first time, we include the effects of
finite temperature and density on the kinetic-mixing parameter, epsilon, in
this environment. This causes the constraints on epsilon to weaken with the
dark-photon mass below ~ 15 MeV. For large-enough values of epsilon, it is well
known that dark photons can be reabsorbed within the supernova. Since the rates
of reabsorption processes decrease as the dark-photon energy increases, we
point out that dark photons with energies above the Wien peak can escape
without scattering, contributing more to energy loss than is possible assuming
a blackbody spectrum. Furthermore, we estimate the systematic uncertainties on
the cooling bounds by deriving constraints assuming one analytic and four
different simulated temperature and density profiles of the proto-neutron star.
Finally, we estimate also the systematic uncertainty on the bound by varying
the distance across which dark photons must propagate from their point of
production to be able to affect the star. This work clarifies the bounds from
SN1987A on the dark-photon parameter space.
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Data science is creating very exciting trends as well as significant
controversy. A critical matter for the healthy development of data science in
its early stages is to deeply understand the nature of data and data science,
and to discuss the various pitfalls. These important issues motivate the
discussions in this article.
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Environmental degradation, global pandemic and severing natural resource
related problems cater to increase demand resulting from migration is nightmare
for all of us. Huge flocks of people are rushing towards to earn, to live and
to lead a better life. This they do for their own development often ignoring
the environmental cost. With existing model, this paper looks at out migration
(interstate) within India focusing on the various proximate and fundamental
causes relating to migration. The author deploys OLS to see those fundamental
causes. Obviously, these are not exhaustive cause, but definitely plays a role
in migration decision of individual. Finally, this paper advocates for some
policy prescription to cope with this problem.
|
The status of the theoretical predictions for the top-anti top production in
hadronic collisions is shortly reviewed, paying a articular attention to the
analytic calculation of the two-loop QCD corrections to the parton-level matrix
elements.
|
A $\theta$ term, which couples to topological charge, is added to the lattice
$CP^{N-1}$ model. The strong-coupling character expansion is developed. The
series for the free energy and mass gap are respectively computed to tenth
order and fourth order. Several features of the strong-coupling analysis
emerge. One is the loss of superconfinement. Another is that in the
intermediate coupling constant region, there are indications of a transition to
a deconfining phase when $\theta$ is sufficiently large. The transition is like
the one which has been observed in Monte Carlo simulations of a similar lattice
$CP^{N-1}$ action.
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In this paper we addressed the cooperative transport problem for a team of
autonomous surface vehicles (ASVs) towing a single buoyant load. We consider
the dynamics of the constrained system and decompose the cooperative transport
problem into a collection of subproblems. Each subproblem consists of an ASV
and load pair where each ASV is attached to the load at the same point. Since
the system states evolve on a smooth manifold, we use the tools from
differential geometry to model the holonomic constraint arising from the
cooperative transport problem and the non-holonomic constraints arising from
the ASV dynamics. We then synthesize distributed feedback control strategies
using the proposed mathematical modeling framework to enable the team transport
the load on a desired trajectory. We experimentally validate the proposed
strategy using a team of micro ASVs.
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With the proliferation of LLM-integrated applications such as GPT-s, millions
are deployed, offering valuable services through proprietary instruction
prompts. These systems, however, are prone to prompt extraction attacks through
meticulously designed queries. To help mitigate this problem, we introduce the
Raccoon benchmark which comprehensively evaluates a model's susceptibility to
prompt extraction attacks. Our novel evaluation method assesses models under
both defenseless and defended scenarios, employing a dual approach to evaluate
the effectiveness of existing defenses and the resilience of the models. The
benchmark encompasses 14 categories of prompt extraction attacks, with
additional compounded attacks that closely mimic the strategies of potential
attackers, alongside a diverse collection of defense templates. This array is,
to our knowledge, the most extensive compilation of prompt theft attacks and
defense mechanisms to date. Our findings highlight universal susceptibility to
prompt theft in the absence of defenses, with OpenAI models demonstrating
notable resilience when protected. This paper aims to establish a more
systematic benchmark for assessing LLM robustness against prompt extraction
attacks, offering insights into their causes and potential countermeasures.
Resources of Raccoon are publicly available at
https://github.com/M0gician/RaccoonBench.
|
We show that the Markov semigroup obtained by Floricel in [Flo08] compressing
the $E_0$-semigroup of Skeide [Ske06], does not consist of endomorphisms. It,
therefore, cannot be the tail flow of an $E_0$-semigroup. As a corollary of our
result, Floricel's construction will allow to get examples of proper type III
Markov semigroups that are not tensor products of simpler ones, provided we
find type III Arveson systems that do not factor into tensor products.
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With the probe limit, we investigate the behavior of the electric
permittivity and effective magnetic permeability and related optical properties
in the s-wave holographic superconductors. In particular, our result shows that
unlike the strong coupled systems which admit a gravity dual of charged black
holes in the bulk, the electric permittivity and effective magnetic
permeability are unable to conspire to bring about the negative
Depine-Lakhtakia index at low frequencies, which implies that the negative
phase velocity does not appear in the holographic superconductors under such a
situation.
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We describe the realization of a magnetically guided beam of cold rubidium
atoms, with a flux of $7\times 10^9$ atoms/s, a temperature of 400 $\mu$K and a
mean velocity of 1 m/s. The rate of elastic collisions within the beam is
sufficient to ensure thermalization. We show that the evaporation induced by a
radio-frequency wave leads to appreciable cooling and increase in phase space
density. We discuss the perspectives to reach the quantum degenerate regime
using evaporative cooling.
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It is generally believed that in the epoch prior to the formation of the
first stars, the Universe was completely dark (the period is therefore known as
the Dark Ages). Usually, the start of this epoch is placed at the photon
decoupling. In this work, we investigate the question, whether there was enough
light during the dark epoch for a human eye to see. We use the black body
spectrum of the Universe to find the flux of photon energy for different
temperatures and compare them with visual limits of brightness and darkness. We
find that the Dark Ages actually began approximately 6 million years later than
commonly stated.
|
Recently by Casas, Ladra and Rozikov a notion of a chain of evolution
algebras is introduced. This chain is a dynamical system the state of which at
each given time is an evolution algebra. The sequence of matrices of the
structural constants for this chain of evolution algebras satisfies the
Chapman-Kolmogorov equation. In this paper we construct 25 distinct examples of
chains of two-dimensional evolution algebras.
For all of these 25 chains we study the behavior of the baric property, the
behavior of the set of absolute nilpotent elements and dynamics of the set of
idempotent elements depending on the time.
|
AFM-based technique of nanolithography is proposed. The method enables rapid
point by point indentation with a sharp tip. When used in tandem with
single-crystal diamond tips, this technique allows the creation of high aspect
ratio grooves in hard materials, such as silicon or metals. Examples of
fabricated groove arrays on Si surface with 30-100 nm pitches and 5-32 nm
depths are presented. Cutting of a 63nm thick metal magnetic film demonstrated.
The resulting structure is studied by use of magnetic force microscopy.
|
The form factors and the coupling constant of the $B_s^* B K$ vertex are
calculated using the QCD sum rules method. Three point correlation functions
are computed considering both $K$ and $B$ mesons off-shell and, after an
extrapolation of the QCDSR results, we obtain the coupling constant of the
vertex. We study the uncertainties in our result by calculating a third form
factor obtained when the $B^*_s$ is the off-shell meson, considering other
acceptable structures and computing the variations of the sum rules'
parameters. The form factors obtained have different behaviors but their
simultaneous extrapolations reach to the same value of the coupling constant
$g_{B_s^* B K}=10.6 \pm 1.7$. We compare our result with other theoretical
estimates.
|
Magnetic fields may play a dominant role in gamma-ray bursts, and recent
observations by the Fermi satellite indicate that GeV radiation, when detected,
arrives delayed by seconds from the onset of the MeV component. Motivated by
this, we discuss a magnetically dominated jet model where both magnetic
dissipation and nuclear collisions are important. We show that, for parameters
typical of the observed bursts, such a model involving a realistic jet
structure can reproduce the general features of the MeV and a separate GeV
radiation component, including the time delay between the two. The model also
predicts a multi-GeV neutrino component.
|
We propose a straightforward sample-based technique to calibrate the axial
detection in 3D single molecule localization microscopy (SMLM). Using
microspheres coated with fluorescent molecules, the calibration curves of
PSF-shaping- or intensity-based measurements can be obtained for any required
depth range from a few hundreds of nanometers to several tens of microns. This
experimental method takes into account the effect of the spherical aberration
without requiring computational correction.
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When data are incomplete, a random vector Y for the data process together
with a binary random vector R for the process that causes missing data, are
modelled jointly. We review conditions under which R can be ignored for drawing
likelihood inferences about the distribution for Y. The standard approach of
Rubin (1976) and Seaman et. al. (2013) Statist. Sci., 28:2 pp. 257--268
emulates complete-data methods exactly, and directs an investigator to choose a
full model in which missing at random (MAR) and distinct of parameters holds if
the goal is not to use a full model. Another interpretation of ignorability
lurking in the literature considers ignorable likelihood estimation
independently of any model for the conditional distribution R given Y. We
discuss shortcomings of the standard approach, and argue that the alternative
gives the `right' conditions for ignorability because it treats the problem on
its merits, rather than emulating methodology developed for when the
investigator is in possession of all of the data.
|
We report the effects of variation in length on the electronic structure of
CdSe nanorods derived from atomic clusters and passivated by fictitious
hydrogen atoms. These nanorods are augmented by attaching gold clusters at both
the ends to form a nanodumbbell. The goal is to assess the changes at nanolevel
after formation of contacts with gold clusters serving as electrodes and
compare the results with experimental observations [PRL, 95, 056805 (2005)].
Calculations involving nanorods of length 4.6 Angstrom to 116.6 Angstrom are
performed using density functional theory implemented within plane-wave basis
set. The binding energy per atom saturates for nanorod of length 116.6
Angstrom. It is interesting to note that upon attaching gold clusters, the
nanorods shorter than 27 Angstrom develop metallicity by means of metal induced
gap states (MIGS). Longer nanorods exhibit a nanoscale Schottky barrier
emerging at the center. For these nanorods, interfacial region closest to the
gold electrodes shows a finite density of states in the gap due to MIGS, which
gradually decreases towards the center of the nanorod opening up a finite gap.
Bader charge analysis indicates localized charge transfer from metal to
semiconductor.
|
The action reaction principle is violated in the standard formulation of
Quantum Mechanics, so that its phase space is incomplete. Moreover, projection
of state of a quantum system under indirect measurement, when there are
alternative virtual paths and one of them is discarded by negative detection
implies, according to the action reaction principle, a reaction on the
detector, although its macroscopic state does not change. If all interactions
are local, mediated by fields with relativistically causal evolution, some
system, different from the particle which follows another path, must locally
interact with the detector. Relativistic locality and the action reaction
principle predict the existence of de Broglie fields. A formulation of Quantum
Mechanics in extended Hilbert spaces is presented, in which kinematic and
dynamical representations of physical magnitudes are distinguished.
|
We discuss a simple theory for neutrino masses where the total lepton number
is a local gauge symmetry spontaneously broken below the multi-TeV scale. In
this context, the neutrino masses are generated through the canonical seesaw
mechanism and a Majorana dark matter candidate is predicted from anomaly
cancellation. We discuss in great detail the dark matter annihilation channels
and find out the upper bound on the symmetry breaking scale using the
cosmological bounds on the relic density. Since in this context the dark matter
candidate has suppressed couplings to the Standard Model quarks, one can
satisfy the direct detection bounds even if the dark matter mass is close to
the electroweak scale. This theory predicts a light pseudo-Nambu-Goldstone
boson (the Majoron) associated to the mechanism of neutrino mass. We discuss
briefly the properties of the Majoron and the impact of the Big Bang
Nucleosynthesis bounds.
|
An absorption feature is occasionally reported around 11 microns in
astronomical spectra, including those of forming stars. Candidate carriers
include water ice, polycyclic aromatic hydrocarbons (PAHs), silicon carbide,
crystalline silicates or even carbonates. All are known constituents of cosmic
dust in one or more types of environments, though not necessarily together. In
this paper we present new ground-based 8-13 micron spectra of one evolved star,
several embedded young stellar objects (YSOs) and a background source lying
behind a large column of the interstellar medium (ISM) toward the Galactic
Centre. Our observations, obtained at a spectral resolution of approximately
100, are compared with previous lower resolution data, as well as data obtained
with the Infrared Space Observatory (ISO) on these and other targets. By
presenting a subset of a larger sample our aim is to establish the reality of
the feature and subsequently speculate on its carrier. All evidence points
toward crystalline silicate. For instance, the 11 micron band profile is well
matched with the emissivity of crystalline olivine. Furthermore, the apparent
association of the absorption feature with a sharp polarisation signature in
the spectrum of two previously reported cases suggests a carrier with a
relatively high band strength compared to amorphous silicates. If true, this
would either set back the evolutionary stage in which silicates are
crystallised, either to the embedded phase or even before within the ISM, or
else the silicates ejected from the outflows of evolved stars retain some of
their crystalline identity during their long residence in the ISM.
|
Observed chemical species in the Venusian mesosphere show local-time
variabilities. SO2 at the cloud top exhibits two local maxima over local time,
H2O at the cloud top is uniformly distributed, and CO in the upper atmosphere
shows a statistical difference between the two terminators. In this study, we
investigated these local-time variabilities using a three-dimensional (3D)
general circulation model (GCM) in combination with a two-dimensional (2D)
chemical transport model (CTM). Our simulation results agree with the observed
local-time patterns of SO2, H2O, and CO. The two-maximum pattern of SO2 at the
cloud top is caused by the superposition of the semidiurnal thermal tide and
the retrograde superrotating zonal (RSZ) flow. SO2 above 85 km shows a large
day-night difference resulting from both photochemistry and the sub-solar to
anti-solar (SS-AS) circulation. The transition from the RSZ flows to SS-AS
circulation can explain the CO difference between two terminators and the
displacement of the CO local-time maximum with respect to the anti-solar point.
H2O is long-lived and exhibits very uniform distribution over space. We also
present the local-time variations of HCl, ClO, OCS and SO simulated by our
model and compare to the sparse observations of these species. This study
highlights the importance of multidimensional CTMs for understanding the
interaction between chemistry and dynamics in the Venusian mesosphere.
|
We study the structure of the $RO(G)$-graded homotopy Mackey functors of any
Eilenberg-MacLane spectrum $H\underline{M}$ for $G$ a cyclic $p$-group. When
$\underline{R}$ is a Green functor, we define orientation classes $u_V$ for
$H\underline{R}$ and deduce a generalized gold relation. We deduce the
$a_V,u_V$-isomorphism regions of the $RO(G)$-graded homotopy Mackey functors
and prove two induction theorems. As applications, we compute the positive cone
of $H\underline{\mathbb{A}}$, as well as the positive and negative cones of
$H\underline{\mathbb{Z}}$. The latter two cones are essential to the slice
spectral sequences of $MU^{((C_{2^n}))}$ and its variants.
|
We investigate the rotational properties of molecular hydrogen and its
isotopes physisorbed on the surfaces of graphene and hexagonal boron nitride
($h$-BN), grown on Ni(111), Ru(0001), and Rh(111), using rotational excitation
spectroscopy (RES) with the scanning tunneling microscope. The rotational
thresholds are in good agreement with $\Delta J=2$ transitions of freely
spinning para-H$_2$ and ortho-D$_2$ molecules. The line shape variations in RES
for H$_2$ among the different surfaces can be traced back and naturally
explained by a resonance mediated tunneling mechanism. RES data for
H$_2$/$h$-BN/Rh(111) suggests a local intrinsic gating on this surface due to
lateral variations in the surface potential. An RES inspection of H$_2$, HD,
and D$_2$ mixtures finally points to a multi molecule excitation, since either
of the three $J=0\rightarrow2$ rotational transitions are simultaneously
present, irrespective of where the spectra were recorded in the mixed
monolayer.
|
This study investigates the accessibility of open-source electronic health
record (EHR) systems for individuals who are visually impaired or blind.
Ensuring the accessibility of EHRs to visually impaired users is critical for
the diversity, equity, and inclusion of all users. The study used a combination
of automated and manual accessibility testing techniques like screen readers to
evaluate the accessibility of three widely used open-source EHR systems. Our
assessment focused on the performance of three popular screen readers,
including JAWS (Windows), NVDA (Windows), and Apple VoiceOver (OSX). The
evaluation revealed that although each of the three systems was partially
accessible, there is room for improvement, particularly regarding keyboard
navigation and screen reader compatibility. The study concludes with
recommendations for making EHR systems more inclusive for all users and more
accessible.
|
We present a reinforcement learning-based solution to autonomously race on a
miniature race car platform. We show that a policy that is trained purely in
simulation using a relatively simple vehicle model, including model
randomization, can be successfully transferred to the real robotic setup. We
achieve this by using novel policy output regularization approach and a lifted
action space which enables smooth actions but still aggressive race car
driving. We show that this regularized policy does outperform the Soft Actor
Critic (SAC) baseline method, both in simulation and on the real car, but it is
still outperformed by a Model Predictive Controller (MPC) state of the art
method. The refinement of the policy with three hours of real-world interaction
data allows the reinforcement learning policy to achieve lap times similar to
the MPC controller while reducing track constraint violations by 50%.
|
We investigate the physical processes occuring in the multiphase gas of a
damped Ly\alpha system (DLA). We base our analysis on a high quality Keck HIRES
spectrum of the QSO J1211+0422 in which a DLA is detected at z=2.377. There is
little contamination of the high-ion (OVI, NV, CIV, SiIV) absorption, allowing
us to explore the properties of the highly ionized gas and its connection to
other gas-phases. The metallicity ([Z/H]=-1.41+/-0.08), HI column density (log
N(HI)=20.80+/-0.10), full-width velocity (\Delta(v_ neut)=70 km/s) and relative
abundances ([Si/Fe]=+0.23+/-0.05 and [N/Si]=-0.88+/-0.07) of this DLA are not
unusual. However, we derive the lowest CII* cooling rate in a DLA, l_c <
10^{-27.8} erg/s per H atom (3\sigma). Using this stringent limit, we show that
the neutral gas (confined at |v|<+39 km/s) must be warm and the star formation
rate is <7.1x10^{-3} M_odot/yr/kpc^2. Surprisingly, the gas shows strong,
complex absorption profiles from highly ionized gas whose kinematics appear
connected to each other and the low ions. The total amount of highly and weakly
ionized gas is very large with N(HII)/N(HI)>1.5. At |v|>+39 km/s, the gas is
fully and highly ionized (H+/H~1, N(CIV)>>N(CII), N(SiIV)>>N(SiII)). Based on
ionization models, OVI and NV are generally difficult to produce by hard
photons, while SiIV and CIV can be photoionized to a large extent. There is,
however, no evidence of OVI-bearing gas at T~10^6 K associated with this DLA.
In contrast, there is some evidence for narrow OVI, NV, and CIV components
(unexplained by photoionization), implying too low temperatures (T < 10^5 K)
for simple collisional ionization models to produce their observed column
densities. Stellar feedback is a possible source for producing the high ions,
but we cannot rule out accretion of non-pristine material onto the protogalaxy.
|
We characterize the phase diagram of anisotropic Heisenberg spin glasses,
finding both the spin and the chiral glass transition. We remark the presence
of strong finite-size effects on the chiral sector. We find a unique phase
transition for the chiral and spin glass sector, in the Universality class of
Ising spin glasses. We focus on keeping finite-size effects under control, and
we stress that they are important to understand experiments. Thanks to large
GPU clusters we have been able to thermalize cubic lattices with up to 64x64x64
spins, over a vast range of temperatures.
|
Machine Learning has become the bedrock of recent advances in text, image,
video, and audio processing and generation. Most production systems deal with
several models during deployment and training, each with a variety of tuned
hyperparameters. Furthermore, data collection and processing aspects of ML
pipelines are receiving increasing interest due to their importance in creating
sustainable high-quality classifiers. We present EdnaML, a framework with a
declarative API for reproducible deep learning. EdnaML provides low-level
building blocks that can be composed manually, as well as a high-level pipeline
orchestration API to automate data collection, data processing, classifier
training, classifier deployment, and model monitoring. Our layered API allows
users to manage ML pipelines at high-level component abstractions, while
providing flexibility to modify any part of it through the building blocks. We
present several examples of ML pipelines with EdnaML, including a large-scale
fake news labeling and classification system with six sub-pipelines managed by
EdnaML.
|
We investigate a multi-qubit quantum battery-charger model, focusing on its
potential emulation on a superconducting qubit chip. Using a large-spin
representation, we first obtain the analytical form of the energy $E_B(t)$,
power $P_B(t)$ and their maximum values, $E_B^{\rm max}$ and $P_B^{\rm max}$,
of the battery part by means of the antiferromagnetic Holstein-Primakoff
(AFM-HP) transformation within the low-energy approximation. In this case, our
results show that superextensive scaling behavior of $P_B^{\rm max}$ ensues. By
further combining these with the ones obtained via exact diagonalization (ED),
we classify the dynamics of various physical quantities, including the
entanglement between the battery and charger parts for system sizes
encompassing over 10,000 qubits. Finally, by checking a diverse set of system
configurations, including either a fixed battery size with growing number of
charger qubits, or when both parts simultaneously grow, we classify the system
size scalings of $E_B^{\rm max}$ and $P_B^{\rm max}$, relating it with the
entanglement entropy in the system. In agreement with the analytical results,
robust superextensive behavior of $P_B^{\rm max}$ is also observed in this
case. Our work provides an overall guide for expected features in experiments
of quantum batteries emulated in superconducting qubit platforms, in particular
ones that exhibit long-range couplings.
|
We estimate the differential and total cross sections for both the
photoproduction of vector D*-meson and its yield in deep inelastic scattering
at the HERA collider in the framework of model motivated by perturbative
calculations in QCD. The offered model allows us to take into account higher
twists over the transverse momentum of meson at p_T ~ m_c and to correctly
approach the dominance of $c$-quark fragmentation at p_T >> m_c. We consider a
possibility for the hadronization of color-octet c q-bar state into the meson.
The combined contribution by the singlet and octet-color terms results in a
good agreement with the experimental data for both the photoproduction and the
production in deep inelastic scattering.
|
We prove that the braided Thompson's groups $V_{\rm br}$ and $F_{\rm br}$ are
of type $F_\infty$, confirming a conjecture by John Meier. The proof involves
showing that matching complexes of arcs on surfaces are highly connected. In an
appendix, Zaremsky uses these connectivity results to exhibit families of
subgroups of the pure braid group that are highly generating, in the sense of
Abels and Holz.
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Let $R$ be a commutative, local, Noetherian ring. In a past article, the
first author developed a theory of $R$-algebras, termed seeds, that can be
mapped to balanced big Cohen-Macaulay $R$-algebras. In prime characteristic
$p$, seeds can be characterized based on the existence of certain
colon-killers, integral extensions of seeds are seeds, tensor products of seeds
are seeds, and the seed property is stable under base change between complete,
local domains. As a result, there exist directed systems of big Cohen-Macaulay
algebras over complete, local domains. In this work, we will show that these
properties can be extended to analogous results in equal characteristic zero.
The primary tool for the extension will be the notion of ultraproducts for
commutative rings as developed by Schoutens and Aschenbrenner.
|
Recent empirical studies suggest that the volatilities associated with
financial time series exhibit short-range correlations. This entails that the
volatility process is very rough and its autocorrelation exhibits sharp decay
at the origin. Another classic stylistic feature often assumed for the
volatility is that it is mean reverting. In this paper it is shown that the
price impact of a rapidly mean reverting rough volatility model coincides with
that associated with fast mean reverting Markov stochastic volatility models.
This reconciles the empirical observation of rough volatility paths with the
good fit of the implied volatility surface to models of fast mean reverting
Markov volatilities. Moreover, the result conforms with recent numerical
results regarding rough stochastic volatility models. It extends the scope of
models for which the asymptotic results of fast mean reverting Markov
volatilities are valid. The paper concludes with a general discussion of
fractional volatility asymptotics and their interrelation. The regimes
discussed there include fast and slow volatility factors with strong or small
volatility fluctuations and with the limits not commuting in general. The
notion of a characteristic term structure exponent is introduced, this exponent
governs the implied volatility term structure in the various asymptotic
regimes.
|
An overview of the author's papers on the new approach to the Brownian
coagulation theory and its generalization to the diffusion-limited reaction
rate theory is presented. The traditional diffusion approach of the
Smoluchowski theory for coagulation of colloids is critically analyzed and
shown to be valid only in the particular case of coalescence of small particles
with large ones. It is shown that, owing to rapid diffusion mixing, coalescence
of comparable size particles occurs in the kinetic regime, realized under
condition of homogeneous spatial distribution of particles, in the two modes,
continuum and free molecular. Transition from the continuum to the free
molecular mode can be described by the interpolation expression derived within
the new analytical approach with fitting parameters that can be specified
numerically, avoiding semi-empirical assumptions of the traditional models. A
similar restriction arises in the traditional approach to the diffusion-limited
reaction rate theory, based on generalization of the Smoluchowski theory for
coagulation of colloids. In particular, it is shown that the traditional
approach is applicable only to the special case of reactions with a large
reaction radius, and becomes inappropriate to calculation of the reaction rate
in the case of a relatively small reaction radius. In the latter, more general
case particles collisions occur mainly in the kinetic regime (rather than in
the diffusion one) characterized by homogeneous (at random) spatial
distribution of particles. The calculated reaction rate for a small reaction
radius in 3-d formally coincides with the expression derived in the traditional
approach for reactions with a large reaction radius, however, notably deviates
at large times from the traditional result in the plane (2-d) geometry, that
has wide applications also in the membrane biology as well as in some other
important areas.
|
Experiments indicate that microdroplets undergoing micellar solubilization in
the bulk of surfactant solution may excite Marangoni flows and self-propel
spontaneously. Surprisingly, self-propulsion emerges even when the critical
micelle concentration is exceeded and the Marangoni effect should be saturated.
To explain this, we propose a novel model of a dissolving active droplet that
is based on two fundamental assumptions: (a) products of the solubilization may
inhibit surfactant adsorption; (b) solubilization prevents the formation of a
monolayer of surfactant molecules at the droplet interface. We use numerical
simulations and asymptotic methods to demonstrate that our model indeed
features spontaneous droplet self-propulsion. Our key finding is that in the
case of axisymmetric flow and concentration fields, two qualitatively different
types of droplet behavior may be stable for the same values of the physical
parameters: steady self-propulsion and steady symmetric pumping. Although
stability of these steady regimes is not guaranteed in the absence of axial
symmetry, we argue that they will retain their respective stable manifolds in
the phase space of a fully 3D problem.
|
The claimed detection of the BICEP2 experiment on the primordial B-mode of
cosmic microwave background polarization suggests that cosmic inflation
possibly takes place at the energy around the grand unified theory scale given
a constraint on the tensor-to-scalar ratio. i.e., $r\simeq 0.20$. In this
report, we revisit single-field (slow-roll) composite inflation and show that,
with the proper choice of parameters and sizeable number of e-foldings, a large
tensor-to-scalar ratio consistent with the recent BICEP2 results can be
significantly produced with regard to the composite paradigms.
|
In this paper, we develop an enhancement of derived algebraic geometry to
apply to $\mathbb{A}^1$-homotopy theory introduced by Morel and Voevodsky. We
call the enhancement "motivic derived algebraic geometry". We shall actually
formulate "motivic" versions of $\infty$-categories, $\infty$-topoi, spectral
schemes and spectral Deligne--Mumford stacks established by Joyal, Lurie,
To\"en and Vezzosi.
By using the language of motivic derived algebraic geometry, we construct the
Grassmannian and the algebraic $K$-theory. Furthermore we formulate the Thom
spaces for vector bundles on (motivic) stacks, and we obtain the algebraic
cobordism for (motivic) stacks. As the main result, we prove that the algebraic
cobordism corepresents the motivic $\infty$-category which has the universal
property of oriented (motivic) $\infty$-categories.
|
Quantized compressive sensing (QCS) deals with the problem of coding
compressive measurements of low-complexity signals with quantized, finite
precision representations, i.e., a mandatory process involved in any practical
sensing model. While the resolution of this quantization clearly impacts the
quality of signal reconstruction, there actually exist incompatible
combinations of quantization functions and sensing matrices that proscribe
arbitrarily low reconstruction error when the number of measurements increases.
This work shows that a large class of random matrix constructions known to
respect the restricted isometry property (RIP) is "compatible" with a simple
scalar and uniform quantization if a uniform random vector, or a random dither,
is added to the compressive signal measurements before quantization. In the
context of estimating low-complexity signals (e.g., sparse or compressible
signals, low-rank matrices) from their quantized observations, this
compatibility is demonstrated by the existence of (at least) one signal
reconstruction method, the projected back projection (PBP), whose
reconstruction error decays when the number of measurements increases.
Interestingly, given one RIP matrix and a single realization of the dither, a
small reconstruction error can be proved to hold uniformly for all signals in
the considered low-complexity set. We confirm these observations numerically in
several scenarios involving sparse signals, low-rank matrices, and compressible
signals, with various RIP matrix constructions such as sub-Gaussian random
matrices and random partial discrete cosine transform (DCT) matrices.
|
In this paper, we apply a Control Lyapunov Function methodology to design two
families of cruise controllers for the two-dimensional movement of autonomous
vehicles on lane-free roads using the bicycle kinematic model. The control
Lyapunov functions are based on measures of the energy of the system with the
kinetic energy expressed in ways similar to Newtonian or relativistic
mechanics. The derived feedback laws (cruise controllers) are decentralized, as
each vehicle determines its control input based on its own speed and on the
relative speeds and distances from adjacent vehicles and from the boundary of
the road. Moreover, the corresponding macroscopic models are derived, obtaining
fluid-like models that consist of a conservation equation and a momentum
equation with pressure and viscous terms. Finally, we show that, by selecting
appropriately the parameters of the feedback laws, we can determine the
physical properties of the "traffic fluid", i.e. we get free hand to create an
artificial fluid that approximates the emerging traffic flow.
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Initial value problems -- a system of ordinary differential equations and
corresponding initial conditions -- can be used to describe many physical
phenomena including those arise in classical mechanics. We have developed a
novel approach to solve physics-based initial value problems using unsupervised
machine learning. We propose a deep learning framework that models the dynamics
of a variety of mechanical systems through neural networks. Our framework is
flexible, allowing us to solve non-linear, coupled, and chaotic dynamical
systems. We demonstrate the effectiveness of our approach on systems including
a free particle, a particle in a gravitational field, a classical pendulum, and
the H\'enon--Heiles system (a pair of coupled harmonic oscillators with a
non-linear perturbation, used in celestial mechanics). Our results show that
deep neural networks can successfully approximate solutions to these problems,
producing trajectories which conserve physical properties such as energy and
those with stationary action. We note that probabilistic activation functions,
as defined in this paper, are required to learn any solutions of initial value
problems in their strictest sense, and we introduce coupled neural networks to
learn solutions of coupled systems.
|
This paper studied the structures of debris discs, focusing on the conditions
that can form an axisymmetric-looking outer disc from systems with inner
clumps. The main conclusion was that as long as the dominated dust grains are
smaller than the blowout size, it is easy to form an axisymmetric-looking outer
debris disc, which is part of a quasi-steady state of the whole system. This
quasi-steady state is established through the balance between grain generations
and a continuous out-going grain flow. Assuming there is an event that starts
planetesimal collisions and the corresponding grain generations, this balance
can be approached in a few thousand years. This result suggested that a
quasi-steady-state picture could solve the possible mass budget problem of
Vega's outer debris disc.
|
We theoretically investigate the features of Ruderman-Kittel-Kasuya-Yosida
(RKKY) exchange interaction between two magnetic impurities, mediated by the
interfacial bound states inside a domain wall (DW). The latter separates the
two regions with oppositely signed inversion symmetry broken terms in graphene
and Weyl semimetal. The DW is modelled by a smooth quantum well which hosts a
number of discrete bound states including a pair of gapless, metallic
zero-energy modes with opposite chiralities. We find clear signatures of these
interfacial chiral bound states in spin response (RKKY exchange interaction)
which is robust to the deformation of the quantum well.
|
The kagome lattice provides a fascinating playground to study geometrical
frustration, topology and strong correlations. The newly-discovered kagome
metals AV$_3$Sb$_5$ (where A can refer to K, Rb, or Cs) exhibit phenomena
including topological band structure, symmetry-breaking charge-density waves
and superconductivity. Nevertheless, the nature of the symmetry breaking in the
charge-density wave phase is not yet clear, despite the fact that it is crucial
in order to understand whether the superconductivity is unconventional. In this
work, we perform scanning birefringence microscopy on all three members of this
family and find that six-fold rotation symmetry is broken at the onset of the
charge-density wave transition in all these compounds. We show that the three
nematic domains are oriented at 120$^\circ$ to each other and propose that
staggered charge-density wave orders with a relative $\pi$ phase shift between
layers is a possibility that can explain these observations. We also perform
magneto-optical Kerr effect and circular dichroism measurements. The onset of
both signals is at the transition temperature, indicating broken time-reversal
symmetry and the existence of the long-sought loop currents in that phase.
|
This paper introduces the \emph{$d$-distance matching problem}, in which we
are given a bipartite graph $G=(S,T;E)$ with $S=\{s_1,\dots,s_n\}$, a weight
function on the edges and an integer $d\in\mathbb Z_+$. The goal is to find a
maximum weight subset $M\subseteq E$ of the edges satisfying the following two
conditions: i) the degree of every node of $S$ is at most one in $M$, ii) if
$s_it,s_jt\in M$, then $|j-i|\geq d$. The question arises naturally, for
example, in various scheduling problems.
We show that the problem is NP-complete in general and admits a simple
$3$-approxi\-mation. We give an FPT algorithm parameterized by $d$ and also
settle the case when the size of $T$ is constant. From an approximability point
of view, we show that the integrality gap of the natural integer programming
model is at most $2-\frac{1}{2d-1}$, and give an LP-based approximation
algorithm for the weighted case with the same guarantee. A combinatorial
$(2-\frac{1}{d})$-approximation algorithm is also presented. Several greedy
approaches are considered, in particular, a local search algorithm that
achieves an approximation ratio of $3/2+\epsilon$ for any constant $\epsilon>0$
in the unweighted case. The novel approaches used in the analysis of the
integrality gap and the approximation ratio of locally optimal solutions might
be of independent combinatorial interest.
|
We study a class of timelike weakly extremal surfaces in flat Minkowski space
$\mathbb R^{1+n}$, characterized by the fact that they admit a $C^1$
parametrization (in general not an immersion) of a specific form. We prove that
if the distinguished parametrization is of class $C^k$, then the surface is
regularly immersed away from a closed singular set of euclidean Hausdorff
dimension at most $1+1/k$, and that this bound is sharp. We also show that,
generically with respect to a natural topology, the singular set of a timelike
weakly extremal cylinder in $\mathbb R^{1+n}$ is 1-dimensional if $n=2$, and it
is empty if $n \ge 4$. For $n=3$, timelike weakly extremal surfaces exhibit an
intermediate behavior.
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Instruction tuning enables pretrained language models to perform new tasks
from inference-time natural language descriptions. These approaches rely on
vast amounts of human supervision in the form of crowdsourced datasets or user
interactions. In this work, we introduce Unnatural Instructions: a large
dataset of creative and diverse instructions, collected with virtually no human
labor. We collect 64,000 examples by prompting a language model with three seed
examples of instructions and eliciting a fourth. This set is then expanded by
prompting the model to rephrase each instruction, creating a total of
approximately 240,000 examples of instructions, inputs, and outputs.
Experiments show that despite containing a fair amount of noise, training on
Unnatural Instructions rivals the effectiveness of training on open-source
manually-curated datasets, surpassing the performance of models such as T0++
and Tk-Instruct across various benchmarks. These results demonstrate the
potential of model-generated data as a cost-effective alternative to
crowdsourcing for dataset expansion and diversification.
|
A measurement process is constructed to project an arbitrary two-mode
$N$-photon state to a maximally entangled $N$-photon state (the {\it
NOON}-state). The result of this projection measurement shows a typical
interference fringe with an $N$-photon de Broglie wavelength. For an
experimental demonstration, this measurement process is applied to a
four-photon superposition state from two perpendicularly oriented type-I
parametric down-conversion processes. Generalization to arbitrary $N$-photon
states projection measurement can be easily made and may have wide applications
in quantum information. As an example, we formulate it for precision phase
measurement.
|
Precise robotic weed control plays an essential role in precision
agriculture. It can help significantly reduce the environmental impact of
herbicides while reducing weed management costs for farmers. In this paper, we
demonstrate that a custom-designed robotic spot spraying tool based on computer
vision and deep learning can significantly reduce herbicide usage on sugarcane
farms. We present results from field trials that compare robotic spot spraying
against industry-standard broadcast spraying, by measuring the weed control
efficacy, the reduction in herbicide usage, and the water quality improvements
in irrigation runoff. The average results across 25 hectares of field trials
show that spot spraying on sugarcane farms is 97% as effective as broadcast
spraying and reduces herbicide usage by 35%, proportionally to the weed
density. For specific trial strips with lower weed pressure, spot spraying
reduced herbicide usage by up to 65%. Water quality measurements of
irrigation-induced runoff, three to six days after spraying, showed reductions
in the mean concentration and mean load of herbicides of 39% and 54%,
respectively, compared to broadcast spraying. These promising results reveal
the capability of spot spraying technology to reduce herbicide usage on
sugarcane farms without impacting weed control and potentially providing
sustained water quality benefits.
|
Using the complete orthonormal sets of radial parts of nonrelativitistic
exponential type orbitals (2,1, 0, 1, 2, ...) and spinor type tensor spherical
harmonics of rank s the new formulae for the 2(2s+1)-component relativistic
spinors useful in the quantum mechanical description of the arbitrary
half-integral spin particles by the generalized Dirac equation introduced by
the author are established in position, momentum and four-dimensional spaces,
where 1/ 2, 3 / 2, 5 / 2, ... s = . These spinors are complete without the
inclusion of the continuum. The 2(2s+1)component spinors obtained are reduced
to the independent sets of two-component spinors defined as a product of
complete orthonormal sets of radial parts of orbitals and twocomponent spinor
type tensor spherical harmonics. We notice that the new idea presented in this
work is the unified treatment of half-integral spin and scalar particles in
position, momentum and four-dimensional spaces. Relations presented in this
study can be useful in the linear combination of atomic orbitals approximation
for the solution of different problems arising in the relativistic quantum
mechanics when the orthonormal basis sets of relativistic exponential type
spinor wave functions and Slater type spinor orbitals in position, momentum and
four -dimensional spaces are employed.
|
Fuzzing is a technique widely used in vulnerability detection. The process
usually involves writing effective fuzz driver programs, which, when done
manually, can be extremely labor intensive. Previous attempts at automation
leave much to be desired, in either degree of automation or quality of output.
In this paper, we propose IntelliGen, a framework that constructs valid fuzz
drivers automatically. First, IntelliGen determines a set of entry functions
and evaluates their respective chance of exhibiting a vulnerability. Then,
IntelliGen generates fuzz drivers for the entry functions through hierarchical
parameter replacement and type inference. We implemented IntelliGen and
evaluated its effectiveness on real-world programs selected from the Android
Open-Source Project, Google's fuzzer-test-suite and industrial collaborators.
IntelliGen covered on average 1.08X-2.03X more basic blocks and 1.36X-2.06X
more paths over state-of-the-art fuzz driver synthesizers FUDGE and FuzzGen.
IntelliGen performed on par with manually written drivers and found 10 more
bugs.
|
We demonstrate that flavor symmetries in warped geometry can provide a
natural explanation for large mixing angles and economically explain the
distinction between the quark and lepton flavor sectors. We show how to
naturally generate Majorana neutrino masses assuming a gauged a U(1)_{B-L}
symmetry broken in the UV that generates see-saw masses of the right size. This
model requires lepton minimal flavor violation (LMFV) in which only Yukawa
matrices (present on the IR brane) break the flavor symmetries. The
symmetry-breaking is transmitted to charged lepton bulk mass parameters as well
to generate the hierarchy of charged lepton masses. With LMFV, a GIM-like
mechanism prevents dangerous flavor-changing processes for charged leptons and
permits flavor-changing processes only in the presence of the neutrino Yukawa
interaction and are therefore suppressed when the overall scale for the
neutrino Yukawa matrix is slightly smaller than one in units of the curvature.
In this case the theory can be consistent with a cutoff of 10 TeV and 3 TeV
Kaluza-Klein masses.
|
We introduce Mysticeti-C, the first DAG-based Byzantine consensus protocol to
achieve the lower bounds of latency of 3 message rounds. Since Mysticeti-C is
built over DAGs it also achieves high resource efficiency and censorship
resistance. Mysticeti-C achieves this latency improvement by avoiding explicit
certification of the DAG blocks and by proposing a novel commit rule such that
every block can be committed without delays, resulting in optimal latency in
the steady state and under crash failures. We further extend Mysticeti-C to
Mysticeti-FPC, which incorporates a fast commit path that achieves even lower
latency for transferring assets. Unlike prior fast commit path protocols,
Mysticeti-FPC minimizes the number of signatures and messages by weaving the
fast path transactions into the DAG. This frees up resources, which
subsequently result in better performance. We prove the safety and liveness in
a Byzantine context. We evaluate both Mysticeti protocols and compare them with
state-of-the-art consensus and fast path protocols to demonstrate their low
latency and resource efficiency, as well as their more graceful degradation
under crash failures. Mysticeti-C is the first Byzantine consensus protocol to
achieve WAN latency of 0.5s for consensus commit while simultaneously
maintaining state-of-the-art throughput of over 200k TPS. Finally, we report on
integrating Mysticeti-C as the consensus protocol into the Sui blockchain,
resulting in over 4x latency reduction.
|
The authors study the interdependent diffusion of an open source software
(OSS) platform and its software complements. They quantify the role of OSS
governance, quality signals such as product ratings, observational learning,
and user actions upon adoption. To do so they extend the Bass Diffusion Model
and apply it to a unique data set of 6 years of daily downloads of the Firefox
browser and 52 of its add-ons. The study then re-casts the resulting
differential equations into non-linear, discrete-time, state space forms; and
estimate them using an MCMC approach to the Extended Kalman Filtern (EKF-MCMC).
Unlike continuous-time filters, the EKF-MCMC approach avoids numerical
integration, and so is more computational efficient, given the length of our
time-series, high dimension of our state space and need to model heterogeneity.
Results show, for example, that observational learning and add-on ratings
increase the demand for Firefox add-ons; add-ons can increase the market
potential of the Firefox platform; a slow add-on review process can diminish
platform success; and OSS platforms (i.e. Chrome and Firefox) compete rather
than complement each other.
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This work presents an innovative method for point set self-embedding, that
encodes the structural information of a dense point set into its sparser
version in a visual but imperceptible form. The self-embedded point set can
function as the ordinary downsampled one and be visualized efficiently on
mobile devices. Particularly, we can leverage the self-embedded information to
fully restore the original point set for detailed analysis on remote servers.
This task is challenging since both the self-embedded point set and the
restored point set should resemble the original one. To achieve a learnable
self-embedding scheme, we design a novel framework with two jointly-trained
networks: one to encode the input point set into its self-embedded sparse point
set and the other to leverage the embedded information for inverting the
original point set back. Further, we develop a pair of up-shuffle and
down-shuffle units in the two networks, and formulate loss terms to encourage
the shape similarity and point distribution in the results. Extensive
qualitative and quantitative results demonstrate the effectiveness of our
method on both synthetic and real-scanned datasets.
|
We show that 2-categories of the form $\mathscr{B}\mbox{-}\mathbf{Cat}$ are
closed under slicing, provided that we allow $\mathscr{B}$ to range over
bicategories (rather than, say, monoidal categories). That is, for any
$\mathscr{B}$-category $\mathbb{X}$, we define a bicategory
$\mathscr{B}/\mathbb{X}$ such that
$\mathscr{B}\mbox{-}\mathbf{Cat}/\mathbb{X}\cong
(\mathscr{B}/\mathbb{X})\mbox{-}\mathbf{Cat}$. The bicategory
$\mathscr{B}/\mathbb{X}$ is characterized as the oplax limit of $\mathbb{X}$,
regarded as a lax functor from a chaotic category to $\mathscr{B}$, in the
2-category $\mathbf{BICAT}$ of bicategories, lax functors and icons. We prove
this conceptually, through limit-preservation properties of the 2-functor
$\mathbf{BICAT}\to 2\mbox{-}\mathbf{CAT}$ which maps each bicategory
$\mathscr{B}$ to the 2-category $\mathscr{B}\mbox{-}\mathbf{Cat}$. When
$\mathscr{B}$ satisfies a mild local completeness condition, we also show that
the isomorphism $\mathscr{B}\mbox{-}\mathbf{Cat}/\mathbb{X}\cong
(\mathscr{B}/\mathbb{X})\mbox{-}\mathbf{Cat}$ restricts to a correspondence
between fibrations in $\mathscr{B}\mbox{-}\mathbf{Cat}$ over $\mathbb{X}$ on
the one hand, and $\mathscr{B}/\mathbb{X}$-categories admitting certain powers
on the other.
|
The ESO-Spitzer extragalactic Imaging Survey (ESIS) is the optical follow up
of the Spitzer Wide-Area InfraRed Extragalactic (SWIRE) survey in the ELAIS-S1
area. This paper presents B, V, R Wide Field Imager observations of the first
1.5 square degree of the ESIS survey. Data reduction is described including
astrometric calibration, illumination and color corrections, completeness and
photometric accuracy estimates. Number counts and color distributions are
compared to literature observational and theoretical data, including
non-evolutionary, PLE, evolutionary and semi-analytic Lambda-CDM galaxy models,
as well as Milky Way stellar predictions. ESIS data are in good agreement with
previous works and are best reproduced by evolutionary and hierarchical
Lambda-CDM scenarios. The ELAIS-S1 area benefits from extensive follow-up from
X-ray to radio frequencies: some potential uses of the multi-wavelength
observations are illustrated. Optical-Spitzer color-color plots promise to be
very powerful tools to disentangle different classes of sources (e.g. AGNs,
starbursts, quiescent galaxies). Ultraviolet GALEX data are matched to optical
and Spitzer samples, leading to a discussion of galaxy properties in the
UV-to-24 microns color space. The spectral energy distribution of a few
objects, from the X-rays to the far-IR are presented as examples of the
multi-wavelength study of galaxy emission components in different spectral
domains.
|
Harmonic maps are nonlinear extensions of harmonic functions. They are
critical points of natural energy functionals between Riemannian manifolds.
Such type of problems appear in Physics, Geometry of Finance and the study of
regularity and singularity uses methods from elliptic PDE, calculus of
variations and geometric measure theory. In this paper, we present a general
review of harmonic maps. It is a survey that aims to cover the main classical
known results regarding the harmonic maps. We present results for the
regularity, blow-ups and rectifiability for local minimizers, stationary
harmonic maps and weakly harmonic maps.
|
The opening of the meson factories twenty years ago provided nuclear physics
with new beams, higher momentum transfers, and new opportunities for precision
measurements. The resulting changes in nuclear physics were substantial,
altering not only the range of physics issues identified with the field but
also the manner and size of the collaborations that do nuclear physics.
Inspired by the talks of this symposium, I discuss some of the accomplishments
as well as some of the goals not yet reached.
|
Generative Retrieval (GR) is an emerging paradigm in information retrieval
that leverages generative models to directly map queries to relevant document
identifiers (DocIDs) without the need for traditional query processing or
document reranking. This survey provides a comprehensive overview of GR,
highlighting key developments, indexing and retrieval strategies, and
challenges. We discuss various document identifier strategies, including
numerical and string-based identifiers, and explore different document
representation methods. Our primary contribution lies in outlining future
research directions that could profoundly impact the field: improving the
quality of query generation, exploring learnable document identifiers,
enhancing scalability, and integrating GR with multi-task learning frameworks.
By examining state-of-the-art GR techniques and their applications, this survey
aims to provide a foundational understanding of GR and inspire further
innovations in this transformative approach to information retrieval. We also
make the complementary materials such as paper collection publicly available at
https://github.com/MiuLab/GenIR-Survey/
|
MoTe$_2$ has recently attracted much attention due to the observation of
pressure-induced superconductivity, exotic topological phase transitions, and
nonlinear quantum effects. However, there has been debate on the intriguing
structural phase transitions among various observed phases of MoTe$_2$, and
their connection to the underlying topological electronic properties. In this
work, by means of density-functional theory (DFT+U) calculations, we
investigate the structural phase transition between the polar T$_d$ and
nonpolar 1T$'$ phases of MoTe$_2$ in reference to a hypothetical high-symmetry
T$_0$ phase that exhibits higher-order topological features. In the T$_d$ phase
we obtain a total of 12 Weyl points, which can be created/annihilated,
dynamically manipulated, and switched by tuning a polar phonon mode. We also
report the existence of a tunable nonlinear Hall effect in T$_d$-MoTe$_2$, and
propose the use of this effect as a probe for the detection of polarity
orientation in polar (semi)metals. By studying the role of dimensionality, we
identify a configuration in which a nonlinear surface response current emerges.
The potential technological applications of the tunable Weyl phase and the
nonlinear Hall effect are discussed.
|
We review an optimal-filter-based algorithm for detecting candidate sources
of unknown and differing size embedded in a stochastic background, and its
application to detecting candidate cosmic bubble collision signatures in
Wilkinson Microwave Anisotropy Probe (WMAP) 7-year observations. The algorithm
provides an enhancement in sensitivity over previous methods by a factor of
approximately two. Moreover, it is optimal in the sense that no other
filter-based approach can provide a superior enhancement of these signatures.
Applying this algorithm to WMAP 7-year observations, eight new candidate bubble
collision signatures are detected for follow-up analysis.
|
In this paper, we present a learning approach to goal assignment and
trajectory planning for unlabeled robots operating in 2D, obstacle-filled
workspaces. More specifically, we tackle the unlabeled multi-robot motion
planning problem with motion constraints as a multi-agent reinforcement
learning problem with some sparse global reward. In contrast with previous
works, which formulate an entirely new hand-crafted optimization cost or
trajectory generation algorithm for a different robot dynamic model, our
framework is a general approach that is applicable to arbitrary robot models.
Further, by using the velocity obstacle, we devise a smooth projection that
guarantees collision free trajectories for all robots with respect to their
neighbors and obstacles. The efficacy of our algorithm is demonstrated through
varied simulations.
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Uniqueness of mass-conserving self-similar solutions to Smoluchowski's
coagulation equation is shown when the coagulation kernel $K$ is given by
$K(x,x\_*)=2(x x\_*)^{-\alpha}$, $(x,x\_*)\in (0,\infty)^2$, for some
$\alpha>0$.
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This paper focuses on the invariance control problem for discrete-time
switched nonlinear systems. The proposed approach computes controlled invariant
sets in a finite number of iterations and directly yields a partition-based
invariance controller using the information recorded during the computation. In
contrast with Lyapunov-based control methods, this method does not require the
subsystems to have common equilibrium points. Algorithms are developed for
computing both outer and inner approximations of the maximal controlled
invariant sets, which are represented as finite unions of intervals. The
general convergence results of interval methods allow us to obtain arbitrarily
precise approximations without any stability assumptions. In addition,
invariant inner approximations can be computed provided that the switched
system satisfies a robustly controlled invariance condition. Under the same
condition, we also prove the existence of an invariance controller based on
partitions of the state space. Our method is illustrated with three examples
drawn from different applications and compared with existing work in the
literature.
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The combined effect of a lateral square superlattice potential and the
Coulomb interaction on the ground state of a two-dimensional electron gas in a
perpendicular magnetic field is studied for different rational values of
$\Gamma$, the inverse of the number of flux quanta per unit cell of the
external potential, at filling factor $\nu =1$ in Landau level $N=0.$ When
Landau level mixing and disorder effects are neglected, increasing the strength
$W_{0}$ of the potential induces a transition, at a critical strength
$W_{0}^{\left( c\right) },$ from a uniform and fully spin polarized state to a
two-dimensional charge density wave (CDW) with a meronlike spin texture at each
maximum and minimum of the CDW. The collective excitations of this vortex-CDW
are similar to those of the Skyrme crystal that is expected to be the ground
state near filling factor $\nu =1$. In particular, a broken U(1) symmetry in
the vortex-CDW results in an extra gapless phase mode that could provide a fast
channel for the relaxation of nuclear spins. The average spin polarization $%
S_{z}$ changes in a continuous or discontinuous manner as $W_{0}$ is increased
depending on whether $\Gamma \in \left[ 1/2,1\right] $ or $\Gamma \in \left[
0,1/2\right] .$ The phase mode and the meronlike spin texture disappear at
large value of $W_{0},$ leaving as the ground state a partially spin-polarized
CDW if $\Gamma \neq 1/2$ or a spin-unpolarized CDW if $\Gamma =1/2.$
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Here a physical model for terminating giant planet formation is outlined and
compared to other methods of late-stage giant planet formation. As has been
pointed out before, gas accreting into a gap and onto the planet will encounter
the planetary dynamo-generated magnetic field. The planetary magnetic field
produces an effective cross section through which gas is accreted. Gas outside
this cross section is recycled into the protoplanetary disk, hence only a
fraction of mass that is accreted into the gap remains bound to the planet.
This cross section inversely scales with the planetary mass, which naturally
leads to stalled planetary growth late in the formation process. We show that
this method naturally leads to Jupiter-mass planets and does not invoke any
artificial truncation of gas accretion, as has been done in some previous
population synthesis models. The mass accretion rate depends on the radius of
the growing planet after the gap has opened, and we show that so-called
hot-start planets tend to become more massive than cold-start planets. When
this result is combined with population synthesis models, it might show
observable signatures of cold-start versus hot-start planets in the exoplanet
population.
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The aim of this work is to contribute to the understanding of the stellar
velocity distribution in the solar neighborhood (SN). We propose that the
structures on the $U-V$ planes, known as the moving groups, can be mainly
explained by the spiral arms perturbations. The applied model of the Galactic
disk and spiral arms, with the parameters defined by observational data and
with pattern speed $\Omega_p=$28.0 km s$^{-1}$ kpc$^{-1}$, is the same that
allowed us to explain the origin of the Local Arm and the Sun's orbit trapped
inside the corotation resonance (CR). We show that the $U-V$ picture of the SN
consists of the main component, associated with the CR, and the inner and outer
structures, which we could associate with the Hercules and Sirius streams,
respectively. The Coma-Berenices and Hyades-Pleiades groups and the Sun itself
belong to the main part. The substructures of Hercules are formed mainly by the
nearby 8/1, 12/1, and even 6/1 inner Lindblad resonances, while Sirius is
shaped by the bulk of overlapping outer Lindblad resonances, -8/1, -12/1,
-16/1, which are stuck to the CR. This richness in resonances only exists near
corotation, which should be of the spiral arms, not of the Galactic bar, whose
stable corotation zone is far away from the Sun. The model's predictions of the
velocity distribution match qualitatively and quantitatively the distribution
provided by Gaia DR2.
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In the framework of the model motivated by perturbative calculations in the
fourth $O(\alpha^3_s\alpha)$-order, the estimates for the $\gamma p$
cross-section of the $D^*$-meson production in the ZEUS experiment are
performed. We factorize the hadronization of $(c\bar q)$-state hardly produced
in perturbative QCD, which allows us to take into account the higher twist
terms in the powers of $1/p_T$ at $p_T\sim m_c$ and to correctly reproduce the
c-quark fragmentation dominant at high $p_T\gg m_c$ to the given order of
$\alpha_s$. We find a good agreement with the experimental data on the
photoproduction, if the color-octet $(c\bar q)$-state is taken into account,
which yields $<O_{(8)} > \approx 0.33-0.49 GeV^3$.
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Approximation and uncertainty quantification methods based on Lagrange
interpolation are typically abandoned in cases where the probability
distributions of one or more {system} parameters are not normal, uniform, or
closely related {distributions}, due to the computational issues that arise
when one wishes to define interpolation nodes for general distributions. This
paper examines the use of the recently introduced weighted Leja nodes for that
purpose. Weighted Leja interpolation rules are presented, along with a
dimension-adaptive sparse interpolation algorithm, to be employed in the case
of high-dimensional input uncertainty. The performance and reliability of the
suggested approach is verified by four numerical experiments, where the
respective models feature extreme value and truncated normal parameter
distributions. Furthermore, the suggested approach is compared with a
well-established polynomial chaos method and found to be either comparable or
superior in terms of approximation and statistics estimation accuracy.
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We consider gluodynamics in case when both color and magnetic charges are
present. We discuss first short distance physics, where only the fundamental
|Q|=1 monopoles introduced via the `t Hooft loop can be considered
consistently. We show that at short distances the external monopoles interact
as pure Abelian objects. This result can be reproduced by a Zwanziger-type
Lagrangian with an Abelian dual gluon. We introduce also an effective dual
gluodynamics which might be a valid approximation at distances where the
monopoles |Q|=2 can be considered as point-like as well. Assuming the monopole
condensation we arrive at a model which is reminiscent in some respect of the
Abelian Higgs model but, unlike the latter leaves space for the Casimir
scaling.
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This paper presents HandFi, which constructs hand skeletons with practical
WiFi devices. Unlike previous WiFi hand sensing systems that primarily employ
predefined gestures for pattern matching, by constructing the hand skeleton,
HandFi can enable a variety of downstream WiFi-based hand sensing applications
in gaming, healthcare, and smart homes. Deriving the skeleton from WiFi signals
is challenging, especially because the palm is a dominant reflector compared
with fingers. HandFi develops a novel multi-task learning neural network with a
series of customized loss functions to capture the low-level hand information
from WiFi signals. During offline training, HandFi takes raw WiFi signals as
input and uses the leap motion to provide supervision. During online use, only
with commercial WiFi, HandFi is capable of producing 2D hand masks as well as
3D hand poses. We demonstrate that HandFi can serve as a foundation model to
enable developers to build various applications such as finger tracking and
sign language recognition, and outperform existing WiFi-based solutions.
Artifacts can be found: https://github.com/SIJIEJI/HandFi
|
Software systems continuously evolve due to new functionalities,
requirements, or maintenance activities. In the context of software evolution,
software refactoring has gained a strategic relevance. The space of possible
software refactoring is usually very large, as it is given by the combinations
of different refactoring actions that can produce software system alternatives.
Multi-objective algorithms have shown the ability to discover alternatives by
pursuing different objectives simultaneously. Performance of such algorithms in
the context of software model refactoring is of paramount importance.
Therefore, in this paper, we conduct a performance analysis of three genetic
algorithms to compare them in terms of performance and quality of solutions.
Our results show that there are significant differences in performance among
the algorithms (e.g., PESA2 seems to be the fastest one, while NSGA-II shows
the least memory usage).
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The security of messages encoded via the widely used RSA public key
encryption system rests on the enormous computational effort required to find
the prime factors of a large number N using classical (i.e., conventional)
computers. In 1994, however, Peter Shor showed that for sufficiently large N a
quantum computer would be expected to perform the factoring with much less
computational effort. This paper endeavors to explain, in a fashion
comprehensible to the non-expert readers of this journal: (i) the RSA
encryption protocol; (ii) the various quantum computer manipulations
constituting the Shor algorithm; (iii) how the Shor algorithm performs the
factoring; and (iv) the precise sense in which a quantum computer employing
Shor's algorithm can be said to accomplish the factoring of very large numbers
with less computational effort than a classical computer can. It is made
apparent that factoring $N$ generally requires many successive runs of the
algorithm. The careful analysis herein reveals, however, that the probability
of achieving a successful factorization on a single run is about twice as large
as commonly quoted in the literature.
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The concept of F-invariance, which previously arose in our analysis of the
integral and half-integral quantum Hall effects, is studied in 2+2\epsilon
spatial dimensions. We report the results of a detailed renormalization group
analysis and establish the renormalizability of the (Finkelstein) action to two
loop order. We show that the infrared behavior of the theory can be extracted
from gauge invariant (F-invariant) quantities only. For these quantities
(conductivity, specific heat) we derive explicit scaling functions. We identify
a bosonic quasiparticle density of states which develops a Coulomb gap as one
approaches the metal-insulator transition from the metallic side. We discuss
the consequences of F-invariance for the strong coupling, insulating regime.
|
In this article, we derive a Stratonovich and Skorohod type change of
variables formula for a multidimensional Gaussian process with low H\"older
regularity (typically lower than 1/4). To this aim, we combine tools from rough
paths theory and stochastic analysis.
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Eliashberg theory (ET) generalized for the account of the peculiar properties
of the finite zone width electron-phonon (EP) systems with the non constant
electron density of states, the electron-hole nonequivalence, chemical
potential renormalization with doping and frequency, and electron correlations
in the vertex function is used for the study of Tc in cuprates. The phonon
contribution to the nodal anomalous electron Green function (GF) in cuprates is
considered. The pairing on the full width of the electron zone was taken into
account, not just on the Fermi surface. It is found that the finite zone width
phenomenon in the newly derived Eliashberg equations for the finite zone width
EP system together with the abrupt fall of the density of states above the
Fermi surface are the crucial factors for the appearance of the high
temperature superconductivity phenomenon. It is shown that near the optimal
doping in the hole-doped cuprates high value is reproduced with the EP
interaction constant obtained from tunnel experiments.
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We provide a minimal solution to the mu/B_mu problem in the gauge mediated
supersymmetry breaking by introducing a Standard Model singlet filed S with a
mass around the messenger scale which couples to the Higgs and messenger
fields. This singlet is nearly supersymmetric and acquires a relatively small
Vacuum Expectation Value (VEV) from its radiatively generated tadpole term.
Consequently, both mu and B_mu parameters receive the tree-level and one-loop
contributions, which are comparable due to the small S VEV. Because there
exists a proper cancellation in such two kinds of contributions to B_mu, we can
have a viable Higgs sector for electroweak symmetry breaking.
|
We generalize Holley-Stroock's perturbation argument from commutative to
quantum Markov semigroups. As a consequence, results on (complete) modified
logarithmic Sobolev inequalities and logarithmic Sobolev inequalities for
self-adjoint quantum Markov process can be used to prove estimates on the
exponential convergence in relative entropy of quantum Markov systems which
preserve a fixed state. This leads to estimates for the decay to equilibrium
for coupled systems and to estimates for mixed state preparation times using
Lindblad operators. Our techniques also apply to discrete time settings, where
we show that the strong data processing inequality constant of a quantum
channel can be controlled by that of a corresponding unital channel.
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A review of the magnetism in the parent compounds of the iron-based
superconductors is given based on the transmission Moessbauer spectroscopy of
57Fe and 151Eu. It was found that the 3d magnetism is of the itinerant
character with varying admixture of the spin-polarized covalent bonds. For the
122 compounds a longitudinal spin density wave (SDW) develops. In the case of
the EuFe2As2 a divalent europium orders antiferromagnetically at much lower
temperature as compared to the onset of SDW. These two magnetic systems remain
almost uncoupled one to another. For the non-stoichiometric Fe(1+x)Te parent of
the 11 family one has a transversal SDW and magnetic order of the interstitial
iron with relatively high and localized magnetic moments. These two systems are
strongly coupled one to another. For the grand parent of the iron-based
superconductors FeAs one observes two mutually orthogonal phase-related
transversal SDW on the iron sites. There are two sets of such spin arrangements
due to two crystallographic iron sites. The FeAs exhibits the highest covalency
among compounds studied, but it has still a metallic character.
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We report on a three--month research project for undergraduate students about
the mass-radius relation of compact stars. The equation of state used is
constrained at low densities by well-established equations of state of the
nuclear phase (the solid crust) and then extended to higher densities with a
phenomenological, parametric approach. A first order phase transition from
hadronic matter to a phase of higher density, assumed to be quark matter is
studied in addition. The mass-radius relation is obtained by solving
numerically the Tolman-Oppenheimer-Volkoff equation. We derive some conditions
for the existence of a third family of compact stars on the form of the
equation of state and its different global properties.
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In this study, we design the 3D-printed phononic crystal (PnC) beam with the
topological interface state for harvesting the mechanical energy of flexural
waves. The PnC beam is formed by arranging periodic grooves on its surface. The
PnC beam with either topologically trivial or non-trivial phase can be achieved
via changing the distance between the grooves. The topological interface state
is then generated by combining two PnCs with distinct topological phases. The
existence of the interface state of the PnC beam is verified both numerically
and experimentally. To convert the mechanical energy into the electricity, a
piezoelectric disc is attached at the interface of the proposed PnC beam.
Compared to the reference beam harvester, the measured output power is
significantly amplified by the PnC harvester at the frequency corresponding to
the interface state. Furthermore, the PnC beam energy harvester based on the
topological state exhibits robustness against geometrical disorders.
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Albertson conjectured that if graph $G$ has chromatic number $r$, then the
crossing number of $G$ is at least that of the complete graph $K_r$. This
conjecture in the case $r=5$ is equivalent to the four color theorem. It was
verified for $r=6$ by Oporowski and Zhao.
In this paper, we prove the conjecture for $7 \leq r \leq 12$ using results
of Dirac; Gallai; and Kostochka and Stiebitz that give lower bounds on the
number of edges in critical graphs, together with lower bounds by Pach et.al.
on the crossing number of graphs in terms of the number of edges and vertices.
|
We consider a well known model for lipid-bilayer membrane vesicles exhibiting
phase separation, incorporating a phase field with finite curvature elasticity.
We prove the existence of a plethora of equilibria, corresponding to
symmetry-breaking solutions of the Euler-Lagrange equations, via global
bifurcation from the spherical state. To the best of our knowledge, this
constitutes the first rigorous existence results for this class of problems. We
overcome several difficulties in carrying this out. Due to inherent in-plane
fluidity combined with finite curvature elasticity, neither the Eulerian
(spatial) nor the Lagrangian (material) description of the model lends itself
well to analysis. Instead we adopt a singularity-free radial-map description
that effectively eliminates the grossly underdetermined in-plane fluid
deformation. The resulting governing equations comprise a quasi-linear elliptic
system with lower-order nonlinear constraints. We then show the equivalence of
our problem to that of finding the zeros of compact vector field. The latter is
not routine; we obtain certain spectral estimates and then shift the principle
part of the operator. With this in hand, we combine well known group-theoretic
ideas for symmetry-breaking with global bifurcation theory to obtain our
results.
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We prove that the speed of a biased random walk on a supercritical
Galton-Watson tree conditioned to survive is analytic within the ballistic
regime. This extends the previous work arXiv:1906.07913 in which it was shown
that the speed is differentiable within the range of bias for which a central
limit theorem holds.
|
We determine the nature of the fixed point sets of groups of order p, acting
on complexes of distinguished p-subgroups (those p-subgroups containing
p-central elements in their centers). The case when G has parabolic
characteristic p is analyzed in detail.
|
Highlights are presented regarding recent developments of the kinetic theory
of granular matter. These concern the discovery of an exact kinetic equation
and a related exact H-theorem both holding for finite $N-$body systems formed
by smooth hard-spheres systems.
|
This letter reports microwave dielectric measurements performed in the
antiferroelectric phase of NaNbO3 ceramics from 100 to 450 K. Remarkable
dielectric relaxations were found within the antiferroelectric phase and in the
vicinity of ferroelectric-antiferroelectric phase transition. Such dielectric
relaxation process was associated with relaxations of polar nanoregions with
strong relaxor-like characteristic. In addition, the microwave dielectric
measurements also revealed an unexpected and unusual anomaly in the relaxation
strength, which was related to a disruption of the antiferroelectric order
induced by a possible AFE-AFE phase transition.
|
The non-Abelian gauge structure of the Standard Model implies the presence of
the multi-boson self-interactions. Precise measurements in experimental and
theoretical studies of these interactions allow not only testing the nature of
the Standard Model but also new physics contribution coming from the beyond
Standard Model. These interactions can be examined using a model-independent
way in effective theory approach that composes the motivation part of this
study. In this paper, we examine the anomalous $ZZ\gamma$ and $Z\gamma\gamma$
neutral triple gauge couplings via the process $e^{-} e^{+}\to Z\gamma$ for the
neutrino-antineutrino pair decay of $Z$ boson. It has performed with both
unpolarized and polarized electron beams at the Compact Linear Collider with
$\sqrt{s}= 3$ TeV. The study focused on $CP$-conserving
$C_{\widetilde{B}W}/{\Lambda^4}$ and $CP$-violating $C_{BB}/{\Lambda^4}$,
$C_{BW}/{\Lambda^4}$, $C_{WW}/{\Lambda^4}$ couplings. Obtained sensitivities on
the anomalous neutral triple gauge couplings with $95\%$ Confidence Level are
given with systematic uncertainties of $0\%$, $5\%$ and $10\%$ for unpolarized,
$-80\%$ and $80\%$ polarized electron beams with integrated luminosities of
${\cal L}_{\text{int}}=5$ $\rm ab^{-1}$, ${\cal L}_{\text{int}}=4$ $\rm
ab^{-1}$ and ${\cal L}_{\text{int}}=1$ $\rm ab^{-1}$, respectively. Comparing
the latest experimental limits and related phenomenological studies, our
results on the anomalous neutral gauge couplings are set more stringent
sensitivity between 10-30 times of magnitude.
|
We use sample of 813 Lyman-break galaxies (LBGs) with 2.6<z<3.4 to perform a
detailed analysis of the redshift-space (z-space) distortions in their
clustering pattern and from them derive confidence levels in the
[Omega_m,beta(z=3)] plane. We model the z-space distortions in the shape of the
correlation function measured in orthogonal directions, xi(sigma,pi). This
modeling requires an accurate description of the real-space correlation
function to be given as an input. From the projection of xi(sigma,pi) in the
angular direction, w_p(sigma), we derive the best fitting amplitude and slope
for the LBG real-space correlation function: r_0=4.48(+0.17)(-0.18) h(-1) Mpc
and gamma=1.76(+0.08)(-0.09) (xi(r)= (r/r_0)^-gamma). A comparison between the
shape of xi(s) and w_p(sigma) suggests that xi(r) deviates from a simple
power-law model, with a break at ~9 h(-1) Mpc. This model is consistent with
the observed projected correlation function. However, due to the limited size
of the fields used, the w_p(sigma) results are limited to sigma < 10 h(-1) Mpc.
Assuming this double power-law model, and by analysing the shape distortions in
xi(sigma,pi), we find the following constraints: beta(z=3) = 0.15
(+0.20)(-0.15), Omega_m = 0.35 (+0.65)(-0.22). Combining these results with
orthogonal constraints from linear evolution of density perturbations, we find
that beta(z=3) = 0.25 (+0.05)(-0.06), Omega_m = 0.55 (+0.45)(-0.16).
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It is known that the linearized Einstein's equation around the pure $AdS$ can
be obtained from the constraint $ \Delta S = \Delta\left< H \right> $, known as
the first law of entanglement, on the boundary $CFT$. The corresponding dual
state in the boundary $CFT$ is the vacuum state around which the linear
perturbation is taken. In this paper we revisit this question, in the context
of $ {AdS}_3/{CFT}_2 $, with the state of the boundary ${CFT}_2$ as a thermal
state. The corresponding dual geometry is a planar BTZ black hole. By
considering the linearized perturbation around this black brane we show that
Einstein's equation follows from the first law of entanglement. The modular
Hamiltonian in a thermal state of the ${CFT}_2$ that we have used has been
recently found in arXiv:1608.01283 [cond-mat.stat-mech].
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Subsets and Splits
Filtered Text Samples
Retrieves 100 samples of text containing the specific phrase "You are a helpful assistant", providing limited insight into the dataset.
Helpful Assistant Text Samples
Returns a limited set of rows containing the phrase 'helpful assistant' in the text, providing basic filtering of relevant entries.