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2102.04107 | Conditional preference statements have been used to compactly represent
preferences over combinatorial domains. They are at the core of CP-nets and
their generalizations, and lexicographic preference trees. Several works have
addressed the complexity of some queries (optimization, dominance in
particular). We extend in this paper some of these results, and study other
queries which have not been addressed so far, like equivalence, thereby
contributing to a knowledge compilation map for languages based on conditional
preference statements. We also introduce a new parameterised family of
languages, which enables to balance expressiveness against the complexity of
some queries.
| [
"cs.AI",
"cs.CC"
] | cs.AI | cs.CC | Artificial Intelligence;Computational Complexity | 374Artificial Intelligence;Computational Complexity
|
2211.14918 | Assuming the Riemann hypothesis, we prove estimates for the variance of the
real and imaginary part of the logarithm of the Riemann zeta-function in short
intervals. We give three different formulations of these results. Assuming a
conjecture of Chan for how often gaps between zeros can be close to a fixed
nonzero value, we prove a conjecture of Berry (1988) for the number variance of
zeta zeros in the non-universal regime. In this range, GUE statistics do not
describe the distribution of the zeros. We also calculate lower-order terms in
the second moment of the logarithm of the modulus of the Riemann zeta-function
on the critical line. Assuming Montgomery's pair correlation conjecture, this
establishes a special case of a conjecture of Keating and Snaith (2000).
| [
"math.NT"
] | math.NT | Number Theory | 4,945Number Theory
|
|
1408.4157 | Sampling orthogonal polynomial bases via Monte Carlo is of interest for
uncertainty quantification of models with high-dimensional random inputs, using
Polynomial Chaos (PC) expansions. It is known that bounding a probabilistic
parameter, referred to as {\it coherence}, yields a bound on the number of
samples necessary to identify coefficients in a sparse PC expansion via
solution to an $\ell_1$-minimization problem. Utilizing asymptotic results for
orthogonal polynomials, we bound the coherence parameter for polynomials of
Hermite and Legendre type under the respective natural sampling distribution.
In both polynomial bases we identify an importance sampling distribution which
yields a bound with weaker dependence on the order of the approximation. For
more general orthonormal bases, we propose the {\it coherence-optimal}
sampling: a Markov Chain Monte Carlo sampling, which directly uses the basis
functions under consideration to achieve a statistical optimality among all
sampling schemes with identical support. We demonstrate these different
sampling strategies numerically in both high-order and high-dimensional,
manufactured PC expansions. In addition, the quality of each sampling method is
compared in the identification of solutions to two differential equations, one
with a high-dimensional random input and the other with a high-order PC
expansion. In both cases the coherence-optimal sampling scheme leads to similar
or considerably improved accuracy.
| [
"math.PR"
] | math.PR | Probability | 5,709Probability
|
|
1604.05454 | We propose elementary and explicit presentations of groups that have no
amenable quotients and yet are SQ-universal. Examples include groups with a
finite classifying space, no Kazhdan subgroups and no Haagerup quotients.
| [
"math.GR"
] | math.GR | Group Theory | 2,913Group Theory
|
|
0910.3573 | The aim of this note is to present some new results concerning "almost
everywhere" well-posedness and stability of continuity equations with measure
initial data. The proofs of all such results can be found in \cite{amfifrgi},
together with some application to the semiclassical limit of the Schr\"odinger
equation.
| [
"math.AP"
] | math.AP | Analysis of PDEs | 205Analysis of PDEs
|
|
2305.02876 | In this paper synchronization techniques using cyclic prefix (CP) are
analyzed to remove the influence of symbol time offset (STO) for correct
synchronization in Orthogonal Frequency Division Multiplex (OFDM) system. For
correct detection of STO using CP two techniques are used. The first one is
based on finding the maximum correlation between two blocks and the second one
on finding the similarity between two blocks which is maximized when the
difference between them is minimized. Two cases are observed. The first one
uses only additive white Gaussian noise (AWGN), while the second also uses the
channel impulse response (CIR) of Rayleigh channel. When channel effect is
added both performances of estimation by correlation and difference deteriorate
if sufficient level of signal to noise (SNR) and proper length of CP are not
provided.
| [
"eess.SP"
] | eess.SP | Signal Processing | 6,402Signal Processing
|
|
1612.09059 | The cloud computing model is rapidly transforming the IT landscape. Cloud
computing is a new computing paradigm that delivers computing resources as a
set of reliable and scalable internet-based services allowing customers to
remotely run and manage these services. Infrastructure-as-a-service (IaaS) is
one of the popular cloud computing services. IaaS allows customers to increase
their computing resources on the fly without investing in new hardware. IaaS
adapts virtualization to enable on-demand access to a pool of virtual computing
resources. Although there are great benefits to be gained from cloud computing,
cloud computing also enables new categories of threats to be introduced. These
threats are a result of the cloud virtual infrastructure complexity created by
the adoption of the virtualization technology.
Breaching the security of any component in the cloud virtual infrastructure
significantly impacts on the security of other components and consequently
affects the overall system security. This paper explores the security problem
of the cloud platform virtual infrastructure identifying the existing security
threats and the complexities of this virtual infrastructure. The paper also
discusses the existing security approaches to secure the cloud virtual
infrastructure and their drawbacks. Finally, we propose and explore some key
research challenges of implementing new virtualization-aware security solutions
that can provide the pre-emptive protection for complex and ever- dynamic cloud
virtual infrastructure.
| [
"cs.CR",
"cs.DC",
"cs.SE"
] | cs.CR | cs.DC | Cryptography and Security;Distributed, Parallel, and Cluster Computing;Software Engineering | 7,267longtail
|
2308.12192 | This paper presents, in a unified fashion, deterministic as well as
statistical Lagrangian-verification techniques. They formally quantify the
behavioral robustness of any time-continuous process, formulated as a
continuous-depth model. To this end, we review LRT-NG, SLR, and GoTube,
algorithms for constructing a tight reachtube, that is, an over-approximation
of the set of states reachable within a given time-horizon, and provide
guarantees for the reachtube bounds. We compare the usage of the variational
equations, associated to the system equations, the mean value theorem, and the
Lipschitz constants, in achieving deterministic and statistical guarantees. In
LRT-NG, the Lipschitz constant is used as a bloating factor of the initial
perturbation, to compute the radius of an ellipsoid in an optimal metric, which
over-approximates the set of reachable states. In SLR and GoTube, we get
statistical guarantees, by using the Lipschitz constants to compute local balls
around samples. These are needed to calculate the probability of having found
an upper bound, of the true maximum perturbation at every timestep. Our
experiments demonstrate the superior performance of Lagrangian techniques, when
compared to LRT, Flow*, and CAPD, and illustrate their use in the robustness
analysis of various continuous-depth models.
| [
"cs.LG",
"cs.AI",
"math.DS",
"math.OC"
] | cs.LG | cs.AI | Machine Learning;Artificial Intelligence;Dynamical Systems;Optimization and Control | 7,267longtail
|
1710.02400 | In their original formulation of superconductivity, the London brothers
predicted the exponential suppression of an $electrostatic$ field inside a
superconductor over the so-called London penetration depth, $\lambda_L$.
Despite a few experiments indicating hints of perturbation induced by
electrostatic fields, no clue has been provided so far on the possibility to
manipulate metallic superconductors via field-effect. Here we report
field-effect control of the supercurrent in $all$-metallic transistors made of
different Bardeen-Cooper-Schrieffer (BCS) superconducting thin films. At low
temperature, our field-effect transistors (FETs) show a monotonic decay of the
critical current under increasing electrostatic field up to total quenching for
gate voltage values as large as $\pm 40$V in titanium-based devices. This
$bipolar$ field effect persists up to $\sim 85\%$ of the critical temperature
($\sim 0.41$K), and in the presence of sizable magnetic fields. A similar
behavior was observed in aluminum thin film FETs. A phenomenological theory
accounts for our observations, and points towards the interpretation in terms
of an electric-field-induced perturbation propagating inside the
superconducting film. In our understanding, this affects the pairing potential
and quenches the supercurrent. These results could represent a groundbreaking
asset for the realization of an $all$-metallic superconducting field-effect
electronics and leading-edge quantum information architectures.
| [
"cond-mat.mes-hall",
"cond-mat.supr-con"
] | cond-mat.mes-hall | cond-mat.supr-con | Mesoscale and Nanoscale Physics;Superconductivity | 4,554Mesoscale and Nanoscale Physics;Superconductivity
|
hep-th/9907020 | We study conserved currents of any integer or half integer spin built from
massless scalar and spinor fields in $AdS_3$. 2-forms dual to the conserved
currents in $AdS_3$ are shown to be exact in the class of infinite expansions
in higher derivatives of the matter fields with the coefficients containing
inverse powers of the cosmological constant. This property has no analog in the
flat space and may be related to the holography of the AdS spaces.
`Improvements' to the physical currents are described as the trivial local
current cohomology class. A complex of spin $s$ currents $(T^s, {\cal D})$ is
defined and the cohomology group $H^1(T^s, {\cal D}) = {\bf C}^{2s+1}$ is
found. This paper is an extended version of hep-th/9906149.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
2208.06850 | Designing navigation strategies for search time optimization remains of
interest in various interdisciplinary branches in science. In here, we focus on
microscopic self-propelled searchers namely active Brownian walkers in noisy
and confined environment which are mediated by one such autonomous strategy
namely resetting. As such, resetting stops the motion and compels the walkers
to restart from the initial configuration intermittently according to an
external timer that does not require control by the walkers. In particular, the
resetting coordinates are either quenched (fixed) or annealed (fluctuating)
over the entire topography. Although the strategy relies upon simple rules, it
shows a significant ramification on the search time statistics in contrast to
the original search. We show that the resetting driven protocols mitigate the
performance of these active searchers based, robustly, on the inherent search
time fluctuations. Notably, for the annealed condition, resetting is always
found to expedite the search process. These features, as well as their
applicability to more general optimization problems starting from queuing
systems, computer science to living systems, make resetting based strategies
universally promising.
| [
"cond-mat.soft",
"cond-mat.stat-mech",
"nlin.AO"
] | cond-mat.soft | cond-mat.stat-mech | Soft Condensed Matter;Statistical Mechanics;Adaptation and Self-Organizing Systems | 7,267longtail
|
2110.09899 | From the 2016 U.S. presidential election to the 2021 Capitol riots to the
spread of misinformation related to COVID-19, many have blamed social media for
today's deeply divided society. Recent advances in machine learning for signed
networks hold the promise to guide small interventions with the goal of
reducing polarization in social media. However, existing models are especially
ineffective in predicting conflicts (or negative links) among users. This is
due to a strong correlation between link signs and the network structure, where
negative links between polarized communities are too sparse to be predicted
even by state-of-the-art approaches. To address this problem, we first design a
partition-agnostic polarization measure for signed graphs based on the signed
random-walk and show that many real-world graphs are highly polarized. Then, we
propose POLE (POLarized Embedding for signed networks), a signed embedding
method for polarized graphs that captures both topological and signed
similarities jointly via signed autocovariance. Through extensive experiments,
we show that POLE significantly outperforms state-of-the-art methods in signed
link prediction, particularly for negative links with gains of up to one order
of magnitude.
| [
"cs.SI",
"cs.LG"
] | cs.SI | cs.LG | Social and Information Networks;Machine Learning | 6,515Social and Information Networks;Machine Learning
|
1911.10849 | The modification of the ground state properties of light atomic nuclei in the
nuclear and stellar medium is addressed, using chemical equilibrium constants
evaluated from a new analysis of the intermediate energy heavy-ion (Xe$+$Sn)
collision data measured by the INDRA collaboration. Three different reactions
are considered, mainly differing by the isotopic content of the emission
source. The thermodynamic conditions of the data samples are extracted from the
measured multiplicities allowing for a parametrization of the in-medium
modification, determined with the single hypothesis that the different nuclear
species in a given sample correspond to a unique common value for the density
of the expanding source. We show that this correction, which was not considered
in previous analyses of chemical constants from heavy ion collisions, is
necessary, since the observables of the analyzed systems show strong deviations
from the expected results for an ideal gas of free clusters. This data set is
further compared to a relativistic mean-field model, and seen to be reasonably
compatible with a universal correction of the attractive $\sigma$-meson
coupling.
| [
"nucl-th",
"astro-ph.HE"
] | nucl-th | astro-ph.HE | Nuclear Theory;High Energy Astrophysical Phenomena | 4,894Nuclear Theory;High Energy Astrophysical Phenomena
|
1604.04083 | After reformulate the incompressible Euler-$\alpha$ equations in 3D smooth
domain with Drichlet data, we obtain the unique classical solutions to
Euler-$\alpha$ equations exist in uniform time interval independent of
$\alpha$. We also show the solution of the Euler-$\alpha$ converge to the
corresponding solution of Euler equation in $L^2$ in space, uniformly in time.
In the sequel, it follows that the $H^s$ $(s>\frac{n}{2}+1)$ solutions of
Euler-$\alpha$ equations exist in any fixed sub-interval of the maximum
existent interval for the Euler equations provided that initial is regular
enough and $\alpha$ is small sufficiently.
| [
"math.AP"
] | math.AP | Analysis of PDEs | 205Analysis of PDEs
|
|
1811.04673 | The oscillation spectrum of pressure waves in stars can be determined by
monitoring their luminosity. For rapidly rotating stars, the corresponding ray
dynamics is mixed, with chaotic and regular zones in phase space. Our numerical
simulations show that the chaotic spectra of these systems exhibit strong peaks
in the autocorrelation which are at odd with Random Matrix Theory predictions.
We explain these peaks through a semiclassical theory based on the peculiar
distribution of the actions of classical periodic orbits. Indeed this
distribution is strongly bunched around the average action between two
consecutive rebounds and its multiples. In stars this phenomenon is a direct
consequence of the strong decrease of the sound speed towards the star surface,
but it would arise in any other physical system with a similar bunching of
orbit actions. The peaks discussed could be observed by space missions and give
insight on the star interiors.
| [
"astro-ph.SR",
"nlin.CD"
] | astro-ph.SR | nlin.CD | Solar and Stellar Astrophysics;Chaotic Dynamics | 6,676Solar and Stellar Astrophysics;Chaotic Dynamics
|
1409.2013 | We study a class of games which model the competition among agents to access
some service provided by distributed service units and which exhibit congestion
and frustration phenomena when service units have limited capacity. We propose
a technique, based on the cavity method of statistical physics, to characterize
the full spectrum of Nash equilibria of the game. The analysis reveals a large
variety of equilibria, with very different statistical properties. Natural
selfish dynamics, such as best-response, usually tend to large-utility
equilibria, even though those of smaller utility are exponentially more
numerous. Interestingly, the latter actually can be reached by selecting the
initial conditions of the best-response dynamics close to the saturation limit
of the service unit capacities. We also study a more realistic stochastic
variant of the game by means of a simple and effective approximation of the
average over the random parameters, showing that the properties of the
average-case Nash equilibria are qualitatively similar to the deterministic
ones.
| [
"cs.GT",
"cond-mat.dis-nn",
"cs.MA",
"physics.soc-ph"
] | cs.GT | cond-mat.dis-nn | Computer Science and Game Theory;Disordered Systems and Neural Networks;Multiagent Systems;Physics and Society | 7,267longtail
|
1403.0868 | Let $\Sigma$ be a Riemann surface of genus $g$ bordered by $n$ curves
homeomorphic to the circle $\mathbb{S}^1$, and assume that $2g+2-n>0$. For such
bordered Riemann surfaces, the authors have previously defined a Teichm\"uller
space which is a Hilbert manifold and which is holomorphically included in the
standard Teichm\"uller space. Based on this, we present alternate models of the
aforementioned Teichm\"uller space and show in particular that it is locally
modelled on a Hilbert space of $L^2$ Beltrami differentials, which are
holomorphic up to a power of the hyperbolic metric, and has a convergent
Weil-Petersson metric.
| [
"math.CV"
] | math.CV | Complex Variables | 1,135Complex Variables
|
|
1802.07931 | Human visual attention is subjective and biased according to the personal
preference of the viewer, however, current works of saliency detection are
general and objective, without counting the factor of the observer. This will
make the attention prediction for a particular person not accurate enough. In
this work, we present the novel idea of personalized attention prediction and
develop Personalized Attention Network (PANet), a convolutional network that
predicts saliency in images with personal preference. The model consists of two
streams which share common feature extraction layers, and one stream is
responsible for saliency prediction, while the other is adapted from the
detection model and used to fit user preference. We automatically collect user
preference from their albums and leaves them freedom to define what and how
many categories their preferences are divided into. To train PANet, we
dynamically generate ground truth saliency maps upon existing detection labels
and saliency labels, and the generation parameters are based upon our collected
datasets consists of 1k images. We evaluate the model with saliency prediction
metrics and test the trained model on different preference vectors. The results
have shown that our system is much better than general models in personalized
saliency prediction and is efficient to use for different preferences.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
1904.04616 | Multiple time scales in dynamical systems lead to a bundling of trajectories
onto slow invariant manifolds (SIMs). Although they are absent in
two-dimensional holomorphic dynamical systems, a bundling of orbits is often
observed as well. They bundle onto special trajectories called separatrices. We
apply numerical methods for the approximation of SIMs to holomorphic flows and
show how a separatrix between two regions of periodic orbits can be
characterized topologically. Complex time reveals a new perspective on
holomorphic dynamical systems.
| [
"math.DS"
] | math.DS | Dynamical Systems | 2,265Dynamical Systems
|
|
2010.05774 | Artificial Intelligence (AI) has rapidly emerged as a key disruptive
technology in the 21st century. At the heart of modern AI lies Deep Learning
(DL), an emerging class of algorithms that has enabled today's platforms and
organizations to operate at unprecedented efficiency, effectiveness, and scale.
Despite significant interest, IS contributions in DL have been limited, which
we argue is in part due to issues with defining, positioning, and conducting DL
research. Recognizing the tremendous opportunity here for the IS community,
this work clarifies, streamlines, and presents approaches for IS scholars to
make timely and high-impact contributions. Related to this broader goal, this
paper makes five timely contributions. First, we systematically summarize the
major components of DL in a novel Deep Learning for Information Systems
Research (DL-ISR) schematic that illustrates how technical DL processes are
driven by key factors from an application environment. Second, we present a
novel Knowledge Contribution Framework (KCF) to help IS scholars position their
DL contributions for maximum impact. Third, we provide ten guidelines to help
IS scholars generate rigorous and relevant DL-ISR in a systematic, high-quality
fashion. Fourth, we present a review of prevailing journal and conference
venues to examine how IS scholars have leveraged DL for various research
inquiries. Finally, we provide a unique perspective on how IS scholars can
formulate DL-ISR inquiries by carefully considering the interplay of business
function(s), application areas(s), and the KCF. This perspective intentionally
emphasizes inter-disciplinary, intra-disciplinary, and cross-IS tradition
perspectives. Taken together, these contributions provide IS scholars a timely
framework to advance the scale, scope, and impact of deep learning research.
| [
"cs.LG",
"cs.CL",
"stat.ME",
"stat.ML"
] | cs.LG | cs.CL | Machine Learning;Computation and Language;Methodology;Machine Learning | 7,267longtail
|
cond-mat/9302031 | The one electron spectral functions for the Luttinger model are discussed for
large but finite systems. The methods presented allow a simple interpretation
of the results. For finite range interactions interesting nonunivesal spectral
features emerge for momenta which differ from the Fermi points by the order of
the inverse interaction range or more. For a simplified model with interactions
only within the branches of right and left moving electrons analytical
expressions for the spectral function are presented which allows to perform the
thermodynamic limit. As in the general spinless model and the model including
spin for which we present mainly numerical results the spectral functions do
not approach the noninteracting limit for large momenta. The implication of our
results for recent high resolution photoemission measurements on quasi
one-dimensional conductors are discussed.
| [
"cond-mat"
] | cond-mat | Condensed Matter | 1,697Condensed Matter
|
|
2303.10753 | This paper proposes a method to detect change points in dynamic social
networks using Fr\'echet statistics. We address two main questions: (1) what
metric can quantify the distances between graph Laplacians in a dynamic network
and enable efficient computation, and (2) how can the Fr\'echet statistics be
extended to detect multiple change points while maintaining the significance
level of the hypothesis test? Our solution defines a metric space for graph
Laplacians using the Log-Euclidean metric, enabling a closed-form formula for
Fr\'echet mean and variance. We present a framework for change point detection
using Fr\'echet statistics and extend it to multiple change points with binary
segmentation. The proposed algorithm uses incremental computation for Fr\'echet
mean and variance to improve efficiency and is validated on simulated and two
real-world datasets, namely the UCI message dataset and the Enron email
dataset.
| [
"cs.SI",
"eess.SP"
] | cs.SI | eess.SP | Social and Information Networks;Signal Processing | 6,533Social and Information Networks;Signal Processing
|
1912.01101 | Deep learning approaches to accelerated MRI take a matrix of sampled
Fourier-space lines as input and produce a spatial image as output. In this
work we show that by careful choice of the offset used in the sampling
procedure, the symmetries in k-space can be better exploited, producing higher
quality reconstructions than given by standard equally-spaced samples or
randomized samples motivated by compressed sensing.
| [
"eess.IV",
"cs.CV",
"cs.LG"
] | eess.IV | cs.CV | Image and Video Processing;Computer Vision and Pattern Recognition;Machine Learning | 3,535Image and Video Processing;Computer Vision and Pattern Recognition;Machine Learning
|
2110.04349 | We establish the non-singular Hasse Principle for pairs of diagonal quartic
equations in $22$ or more variables.
| [
"math.NT"
] | math.NT | Number Theory | 4,945Number Theory
|
|
2209.07192 | SOXS (Son Of X-Shooter) is a single object spectrograph offering a
simultaneous spectral coverage from U- to H-band, built by an international
consortium for the 3.58-m ESO New Technology Telescope at the La Silla
Observatory. It is designed to observe all kind of transients and variable
sources discovered by different surveys with a highly flexible schedule
maintained by the consortium, based on the Target of Opportunity concept. SOXS
is going to be a fundamental spectroscopic partner for any kind of imaging
survey, becoming one of the premier transient follow-up instruments in the
Southern hemisphere. This paper gives an updated status of the project, when
the instrument is in the advanced phase of integration and testing in Europe,
prior to the activities in Chile.
| [
"astro-ph.IM"
] | astro-ph.IM | Instrumentation and Methods for Astrophysics | 3,689Instrumentation and Methods for Astrophysics
|
|
2011.02572 | Scene parsing from images is a fundamental yet challenging problem in visual
content understanding. In this dense prediction task, the parsing model assigns
every pixel to a categorical label, which requires the contextual information
of adjacent image patches. So the challenge for this learning task is to
simultaneously describe the geometric and semantic properties of objects or a
scene. In this paper, we explore the effective use of multi-layer feature
outputs of the deep parsing networks for spatial-semantic consistency by
designing a novel feature aggregation module to generate the appropriate global
representation prior, to improve the discriminative power of features. The
proposed module can auto-select the intermediate visual features to correlate
the spatial and semantic information. At the same time, the multiple skip
connections form a strong supervision, making the deep parsing network easy to
train. Extensive experiments on four public scene parsing datasets prove that
the deep parsing network equipped with the proposed feature aggregation module
can achieve very promising results.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
1610.05829 | This paper considers a model consisting of a kinetic term, Rashba spin-orbit
coupling and short-range Coulomb interaction at zero-temperature. The Coulomb
interaction is decoupled by a mean-field approximation in the spin channel
using field theory methods. The results feature a first-order phase transition
for any finite value of the chemical potential and quantum criticality for
vanishing chemical potential. The Hall conductivity is also computed using Kubo
formula in a mean-field effective Hamiltonian. In the limit of infinite mass
the kinetic term vanishes and all the phase transitions are of second order, in
this case spontaneous symmetry breaking mechanism adds a ferromagnetic metallic
phase to the system and features a zero-temperature quantization of the Hall
conductivity in the insulating one.
| [
"cond-mat.mes-hall"
] | cond-mat.mes-hall | Mesoscale and Nanoscale Physics | 4,450Mesoscale and Nanoscale Physics
|
|
1307.2684 | In this paper we determine the threshold for collapsibility in the
probabilistic model $X_d(n,p)$ of $d$-dimensional simplicial complexes. A lower
bound for this threshold $p=\frac{c_d}{n}$ was established in \cite{ALLM}. Here
we show that this is indeed the correct threshold. Namely, for every $c>c_d$, a
complex drawn from $X_d(n,\frac{c}{n})$ is asymptotically almost surely not
collapsible.
| [
"math.PR",
"math.CO"
] | math.PR | math.CO | Probability;Combinatorics | 5,726Probability;Combinatorics
|
0709.2938 | Community detection and analysis is an important methodology for
understanding the organization of various real-world networks and has
applications in problems as diverse as consensus formation in social
communities or the identification of functional modules in biochemical
networks. Currently used algorithms that identify the community structures in
large-scale real-world networks require a priori information such as the number
and sizes of communities or are computationally expensive. In this paper we
investigate a simple label propagation algorithm that uses the network
structure alone as its guide and requires neither optimization of a pre-defined
objective function nor prior information about the communities. In our
algorithm every node is initialized with a unique label and at every step each
node adopts the label that most of its neighbors currently have. In this
iterative process densely connected groups of nodes form a consensus on a
unique label to form communities. We validate the algorithm by applying it to
networks whose community structures are known. We also demonstrate that the
algorithm takes an almost linear time and hence it is computationally less
expensive than what was possible so far.
| [
"physics.soc-ph"
] | physics.soc-ph | Physics and Society | 5,463Physics and Society
|
|
2111.06681 | We report the experimental observation of Ising superconductivity in
3-dimensional NbSe2 stacked with single-layer MoS2. The angular dependence of
the upper critical magnetic field and the temperature dependence of the upper
parallel critical field confirm the appearance of two-dimensional Ising
superconductivity in the 3-dimensional NbSe2 with single-layer MoS2 overlay. We
show that the superconducting phase has strong Ising spin-orbit correlations
which make the holes spin non-degenerate. Our observation of Ising
superconductivity in heterostructures of few-layer NbSe2 of thickness ~ 15 nm
with single-layer MoS2 raises the interesting prospect of observing topological
chiral superconductors with nontrivial Chern numbers in a momentum-space
spin-split fermionic system.
| [
"cond-mat.supr-con",
"cond-mat.mes-hall"
] | cond-mat.supr-con | cond-mat.mes-hall | Superconductivity;Mesoscale and Nanoscale Physics | 7,083Superconductivity;Mesoscale and Nanoscale Physics
|
2206.02797 | Federated Learning (FL) enables training state-of-the-art Automatic Speech
Recognition (ASR) models on user devices (clients) in distributed systems,
hence preventing transmission of raw user data to a central server. A key
challenge facing practical adoption of FL for ASR is obtaining ground-truth
labels on the clients. Existing approaches rely on clients to manually
transcribe their speech, which is impractical for obtaining large training
corpora. A promising alternative is using semi-/self-supervised learning
approaches to leverage unlabelled user data. To this end, we propose FedNST, a
novel method for training distributed ASR models using private and unlabelled
user data. We explore various facets of FedNST, such as training models with
different proportions of labelled and unlabelled data, and evaluate the
proposed approach on 1173 simulated clients. Evaluating FedNST on LibriSpeech,
where 960 hours of speech data is split equally into server (labelled) and
client (unlabelled) data, showed a 22.5% relative word error rate reduction}
(WERR) over a supervised baseline trained only on server data.
| [
"eess.AS",
"cs.AI",
"cs.CL",
"cs.CV",
"cs.DC",
"cs.LG"
] | eess.AS | cs.AI | Audio and Speech Processing;Artificial Intelligence;Computation and Language;Computer Vision and Pattern Recognition;Distributed, Parallel, and Cluster Computing;Machine Learning | 7,267longtail
|
2204.06061 | Line-of-sight extinction estimates to well-studied young T Tauri and Herbig
Ae/Be stars are based on many different measurements and analysis methods. This
has resulted in wide scatter among the published $A_V$ values for the same
star. In this work, we discuss the challenges in measuring extinction to
actively accreting and especially outbursting young stellar objects (YSOs). We
then explore a method not previously applied to young stars utilizing diffuse
interstellar bands (DIBs). In early-type stars, narrow correlations exist
between DIB equivalent widths and the column density of interstellar material,
and therefore the line-of-sight extinction. Here, we measure equivalent widths
of the 5780 \AA\ and 6614 \AA\ DIB features in a sample of actively accreting
YSOs, and apply a DIB-reddening calibration to estimate reddening and
subsequently extinction. Our calibration is newly derived from a composite of
available literature data and fully accounts for the scatter in these
measurements. We also compare the DIBs-inferred optical line-of-sight
extinction values with previous extinction estimates for our sample stars.
| [
"astro-ph.SR",
"astro-ph.GA"
] | astro-ph.SR | astro-ph.GA | Solar and Stellar Astrophysics;Astrophysics of Galaxies | 6,669Solar and Stellar Astrophysics;Astrophysics of Galaxies
|
hep-th/9202089 | We consider the correlation functions of the tachyon vertex operator of the
super Liouville theory coupled to matter fields in the super Coulomb gas
formulation, on world sheets with spherical topology. After integrating over
the zero mode and assuming that the $s$ parameter takes an integer value, we
subsequently continue it to an arbitrary real number and compute the
correlators in a closed form. We also included an arbitrary number of screening
charges and, as a result, after renormalizing them, as well as the external
legs and the cosmological constant, the form of the final amplitudes do not
modify. The result is remarkably parallel to the bosonic case. For
completeness, we discussed the calculation of bosonic correlators including
arbitrary screening charges.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
1710.08260 | We develop the theory of modulated operators in general principal ideals of
compact operators. For Laplacian modulated operators we establish Connes' trace
formula in its local Euclidean model and a global version thereof. It expresses
Dixmier traces in terms of the vector-valued Wodzicki residue. We demonstrate
the applicability of our main results in the context of log-classical
pseudo-differential operators, studied by Lesch, and a class of operators
naturally appearing in noncommutative geometry.
| [
"math.FA",
"math.OA",
"math.SP"
] | math.FA | math.OA | Functional Analysis;Operator Algebras;Spectral Theory | 2,596Functional Analysis;Operator Algebras;Spectral Theory
|
1805.07055 | We prove surjectivity result in Fr\'echet spaces of Nash-Moser type. That is,
with uniform estimates over all semimorms.
Our method works for functions which are only continuous and G\^ateaux
differentiable like in the recent result of Ekeland.
We present the results in multi-valued setting exploring the relevant notions
of map regularity.
| [
"math.FA"
] | math.FA | Functional Analysis | 2,549Functional Analysis
|
|
1011.6573 | Progress in calculating the spectrum of excited baryons and mesons in lattice
QCD is described. Correlation matrices of sets of spatially-extended hadron
operators have been studied and their effectiveness in facilitating the
extraction of excited-state energies is demonstrated. First applications of the
stochastic LapH method, a new method of estimating the low-lying effects of
quark propagation, are presented.
| [
"hep-lat"
] | hep-lat | High Energy Physics - Lattice | 3,092High Energy Physics - Lattice
|
|
cond-mat/0108228 | We study the effect of the electron-electron interaction on the transport of
spin polarized currents in metals and doped semiconductors in the diffusive
regime. In addition to well-known screening effects, we identify two additional
effects, which depend on many-body correlations and exchange and reduce the
spin diffusion constant. The first is the "spin Coulomb drag" - an intrinsic
friction mechanism which operates whenever the average velocities of up-spin
and down-spin electrons differ. The second arises from the decrease in the
longitudinal spin stiffness of an interacting electron gas relative to a
noninteracting one. Both effects are studied in detail for both degenerate and
non-degenerate carriers in metals and semiconductors, and various limiting
cases are worked out analytically. The behavior of the spin diffusion constant
at and below a ferromagnetic transition temperature is also discussed.
| [
"cond-mat.str-el",
"cond-mat.mes-hall"
] | cond-mat.str-el | cond-mat.mes-hall | Strongly Correlated Electrons;Mesoscale and Nanoscale Physics | 7,016Strongly Correlated Electrons;Mesoscale and Nanoscale Physics
|
1603.00270 | Context. Polarimetric observations of Bok globules frequently show a decrease
in the degree of polarization towards their central dense regions (polarization
holes). This behaviour is usually explained with increased disalignment owing
to high density and temperature, or insufficient angular resolution of a
possibly complex magnetic field structure.
Aims. We investigate whether a significant decrease in polarized emission of
dense regions in Bok globules is possible under certain physical conditions.
For instance, we evaluate the impact of optical depth effects and various
properties of the dust phase.
Methods. We use radiative transfer modelling to calculate the temperature
structure of an analytical Bok globule model and simulate the polarized thermal
emission of elongated dust grains. For the alignment of the dust grains, we
consider a magnetic field and include radiative torque and internal alignment.
Results. Besides the usual explanations, selected conditions of the
temperature and density distribution, the dust phase and the magnetic field are
also able to significantly decrease the polarized emission of dense regions in
Bok globules. Taking submm/mm grains and typical column densities of existing
Bok globules into consideration, the optical depth is high enough to decrease
the degree of polarization by up to {\Delta}P~10%. If limited to the densest
regions, dust grain growth to submm/mm size and accumulated graphite grains
decrease the degree of polarization by up to {\Delta}P~10% and {\Delta}P~5%,
respectively. However, the effect of the graphite grains occurs only if they do
not align with the magnetic field.
| [
"astro-ph.SR",
"astro-ph.GA"
] | astro-ph.SR | astro-ph.GA | Solar and Stellar Astrophysics;Astrophysics of Galaxies | 6,669Solar and Stellar Astrophysics;Astrophysics of Galaxies
|
cs/0601079 | In the UNIX/Linux environment the kernel can log every command process
created by every user using process accounting. This data has many potential
uses, including the investigation of security incidents. However, process
accounting data is also sensitive since it contains private user information.
Consequently, security system administrators have been hindered from sharing
these logs. Given that many interesting security applications could use process
accounting data, it would be useful to have a tool that could protect private
user information in the logs. For this reason we introduce SCRUB-PA, a tool
that uses multi-level multi-dimensional anonymization on process accounting log
files in order to provide different levels of privacy protection. It is our
goal that SCRUB-PA will promote the sharing of process accounting logs while
preserving privacy.
| [
"cs.CR"
] | cs.CR | Cryptography and Security | 1,782Cryptography and Security
|
|
1904.11247 | We present a study of the dynamic magnetic properties of TiN-buffered
epitaxial thin films of the Heusler alloy Fe$_{1.5}$CoGe. Thickness series
annealed at different temperatures are prepared and the magnetic damping is
measured, a lowest value of $\alpha=2.18\times 10^{-3}$ is obtained. The
perpendicular magnetic anisotropy properties in Fe$_{1.5}$CoGe/MgO are also
characterized. The evolution of the interfacial perpendicular anisotropy
constant $K^{\perp}_{\rm S}$ with the annealing temperature is shown and
compared with the widely used CoFeB/MgO interface. A large volume contribution
to the perpendicular anisotropy of $(4.3\pm0.5)\times 10^{5}$ $\rm J/m^3$ is
also found, in contrast with vanishing bulk contribution in common Co- and
Fe-based Heusler alloys.
| [
"cond-mat.mtrl-sci"
] | cond-mat.mtrl-sci | Materials Science | 4,287Materials Science
|
|
astro-ph/0502549 | The curl (B) modes of cosmic microwave background (CMB) polarization
anisotropies are a unique probe of the primordial background of inflationary
gravitational waves (IGWs). Unfortunately, the B-mode polarization anisotropies
generated by gravitational waves at recombination are confused with those
generated by the mixing of gradient-mode (E-mode) and B-mode polarization
anisotropies as CMB photons propagate through the Universe and are
gravitationally lensed. We describe here a method for delensing CMB
polarization anisotropies using observations of anisotropies in the cosmic
21-cm radiation emitted or absorbed by neutral hydrogen atoms at redshifts 10
to 200. While the detection of cosmic 21-cm anisotropies at high resolution is
challenging, a combined study with a relatively low-resolution (but
high-sensitivity) CMB polarization experiment could probe inflationary energy
scales well below the Grand Unified Theory (GUT) scale of 10^{16} GeV --
constraining models with energy scales below 10^{15} GeV (the detectable limit
derived from CMB observations alone). The ultimate theoretical limit to the
detectable inflationary energy scale via this method may be as low as 3 \times
10^{14} GeV.
| [
"astro-ph",
"gr-qc",
"hep-ph",
"hep-th"
] | astro-ph | gr-qc | Astrophysics;General Relativity and Quantum Cosmology;High Energy Physics - Phenomenology;High Energy Physics - Theory | 519Astrophysics;General Relativity and Quantum Cosmology;High Energy Physics - Phenomenology;High Energy Physics - Theory
|
2007.11083 | Reversing the effects of a quantum evolution, for example as is done in error
correction, is an important task for controlling quantum systems in order to
produce reliable quantum devices. When the evolution is governed by a
completely positive map, there exist reversibility conditions, known as the
quantum error correcting code conditions, which are necessary and sufficient
conditions for the reversibility of a quantum operation on a subspace, the code
space. However, if we suppose that the evolution is not described by a
completely positive map, necessary and sufficient conditions are not known.
Here we consider evolutions that do not necessarily correspond to a completely
positive map. We prove that the completely positive map error correcting code
conditions can lead to a code space that is not in the domain of the map,
meaning that the output of the map is not positive. A corollary to our theorem
provides a class of relevant examples. Finally, we provide a set of sufficient
conditions that will enable the use of quantum error correcting code conditions
while ensuring positivity.
| [
"quant-ph"
] | quant-ph | Quantum Physics | 5,985Quantum Physics
|
|
2310.08734 | Linear mechanical systems with time-modulated parameters can harbor
oscillations with amplitudes that grow or decay exponentially with time due to
the phenomenon of parametric resonance. While the resonance properties of
individual oscillators are well understood, identifying the conditions for
parametric resonance in systems of coupled oscillators remains challenging.
Here, we identify internal symmetries that arise from the real-valued and
symplectic nature of classical mechanics and determine the parametric resonance
conditions for periodically time-modulated mechanical metamaterials using these
symmetries. Upon including external symmetries, we find additional conditions
that prohibit resonances at some modulation frequencies for which parametric
resonance would be expected from the internal symmetries alone. In particular,
we analyze systems with space-time symmetry where the system remains invariant
after a combination of discrete translation in both space and time. For such
systems, we identify a combined space-time translation operator that provides
more information about the system than the Floquet operator does, and use it to
derive conditions for one-way amplification of traveling waves. Our results
establish an exact theoretical framework based on symmetries to engineer exotic
responses such as nonreciprocal transport and one-way amplification in
space-time modulated mechanical systems, and can be generalized to all physical
systems that obey space-time symmetry.
| [
"physics.class-ph",
"cond-mat.soft"
] | physics.class-ph | cond-mat.soft | Classical Physics;Soft Condensed Matter | 1,012Classical Physics;Soft Condensed Matter
|
2306.03268 | Large pre-trained neural language models have brought immense progress to
both NLP and software engineering. Models in OpenAI's GPT series now dwarf
Google's BERT and Meta's RoBERTa, which previously set new benchmarks on a wide
range of NLP applications. These models are trained on massive corpora of
heterogeneous data from web crawls, which enables them to learn general
language patterns and semantic relationships. However, the largest models are
both expensive to train and deploy and are often closed-source, so we lack
access to their data and design decisions. We argue that this trend towards
large, general-purpose models should be complemented with single-purpose, more
modestly sized pre-trained models. In this work, we take StackOverflow (SO) as
a domain example in which large volumes of rich aligned code and text data is
available. We adopt standard practices for pre-training large language models,
including using a very large context size (2,048 tokens), batch size (0.5M
tokens) and training set (27B tokens), coupled with a powerful toolkit
(Megatron-LM), to train two models: SOBertBase, with 109M parameters, and
SOBertLarge with 762M parameters, at a budget of just $\$187$ and $\$800$ each.
We compare the performance of our models with both the previous SOTA model
trained on SO data exclusively as well general-purpose BERT models and OpenAI's
ChatGPT on four SO-specific downstream tasks - question quality prediction,
closed question prediction, named entity recognition and obsoletion prediction
(a new task we introduce). Not only do our models consistently outperform all
baselines, the smaller model is often sufficient for strong results. Both
models are released to the public. These results demonstrate that pre-training
both extensively and properly on in-domain data can yield a powerful and
affordable alternative to leveraging closed-source general-purpose models.
| [
"cs.CL",
"cs.SE"
] | cs.CL | cs.SE | Computation and Language;Software Engineering | 1,257Computation and Language;Software Engineering
|
2203.00098 | We consider the periodic non-linear Schr\"odinger equation with non-linearity
given by $|u|^{p-1}u$ for odd $p > 1$ in dimension $1$. We first establish that
the difference between the non-linear evolution and a phase rotation of the the
linear evolution is in a smoother space. We then study forced and damped
defocusing non-linear Schr\"odinger equations of the above type and establish
an analogous smoothing statement that extends globally in time. As a corollary
we establish both existence and smootheness for global attractors in the energy
space.
| [
"math.AP"
] | math.AP | Analysis of PDEs | 205Analysis of PDEs
|
|
cond-mat/0208402 | We consider the survival probability of a particle in the presence of a
finite number of diffusing traps in one dimension. Since the general solution
for this quantity is not known when the number of traps is greater than two, we
devise a perturbation series expansion in the diffusion constant of the
particle. We calculate the persistence exponent associated with the particle's
survival probability to second order and find that it is characterised by the
asymmetry in the number of traps initially positioned on each side of the
particle.
| [
"cond-mat.stat-mech"
] | cond-mat.stat-mech | Statistical Mechanics | 6,821Statistical Mechanics
|
|
2304.03869 | Diffusion-based models have achieved state-of-the-art performance on
text-to-image synthesis tasks. However, one critical limitation of these models
is the low fidelity of generated images with respect to the text description,
such as missing objects, mismatched attributes, and mislocated objects. One key
reason for such inconsistencies is the inaccurate cross-attention to text in
both the spatial dimension, which controls at what pixel region an object
should appear, and the temporal dimension, which controls how different levels
of details are added through the denoising steps. In this paper, we propose a
new text-to-image algorithm that adds explicit control over spatial-temporal
cross-attention in diffusion models. We first utilize a layout predictor to
predict the pixel regions for objects mentioned in the text. We then impose
spatial attention control by combining the attention over the entire text
description and that over the local description of the particular object in the
corresponding pixel region of that object. The temporal attention control is
further added by allowing the combination weights to change at each denoising
step, and the combination weights are optimized to ensure high fidelity between
the image and the text. Experiments show that our method generates images with
higher fidelity compared to diffusion-model-based baselines without fine-tuning
the diffusion model. Our code is publicly available at
https://github.com/UCSB-NLP-Chang/Diffusion-SpaceTime-Attn.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
0712.2739 | Fully 3-dimensional computations of flow through a long pipe demand a huge
number of degrees of freedom, making it very expensive to explore parameter
space and difficult to isolate the structure of the underlying dynamics. We
therefore introduce a `2+epsilon' dimensional model of pipe flow which is a
minimal 3-dimensionalisation of the axisymmetric case: only sinusoidal
variation in azimuth plus azimuthal shifts are retained, yet the same dynamics
familiar from experiments are found. In particular the model retains the
subcritical dynamics of fully resolved pipe flow, capturing realistic localised
`puff'-like structures which can decay abruptly after long times, as well as
global `slug' turbulence. Relaminarisation statistics of puffs reproduce the
memoryless feature of pipe flow and indicate the existence of a Reynolds number
about which lifetimes diverge rapidly, provided that the pipe is sufficiently
long. Exponential divergence of the lifetime is prevalent in shorter periodic
domains. In a short pipe, exact travelling-wave solutions are found nearby to
flow trajectories on the boundary between laminar and turbulent flow. In a long
pipe, the attracting state on the laminar-turbulent boundary is a localised
structure which resembles a smoothened puff. This `edge' state remains
localised even for Reynolds numbers where the turbulent state is global.
| [
"physics.flu-dyn"
] | physics.flu-dyn | Fluid Dynamics | 2,452Fluid Dynamics
|
|
2106.07660 | The classic classification scheme for Active Galactic Nuclei (AGNs) was
recently challenged by the discovery of the so-called changing-state
(changing-look) AGNs (CSAGNs). The physical mechanism behind this phenomenon is
still a matter of open debate and the samples are too small and of
serendipitous nature to provide robust answers. In order to tackle this
problem, we need to design methods that are able to detect AGN right in the act
of changing-state. Here we present an anomaly detection (AD) technique designed
to identify AGN light curves with anomalous behaviors in massive datasets. The
main aim of this technique is to identify CSAGN at different stages of the
transition, but it can also be used for more general purposes, such as cleaning
massive datasets for AGN variability analyses. We used light curves from the
Zwicky Transient Facility data release 5 (ZTF DR5), containing a sample of
230,451 AGNs of different classes. The ZTF DR5 light curves were modeled with a
Variational Recurrent Autoencoder (VRAE) architecture, that allowed us to
obtain a set of attributes from the VRAE latent space that describes the
general behaviour of our sample. These attributes were then used as features
for an Isolation Forest (IF) algorithm, that is an anomaly detector for a "one
class" kind of problem. We used the VRAE reconstruction errors and the IF
anomaly score to select a sample of 8,809 anomalies. These anomalies are
dominated by bogus candidates, but we were able to identify 75 promising CSAGN
candidates.
| [
"astro-ph.IM",
"astro-ph.GA"
] | astro-ph.IM | astro-ph.GA | Instrumentation and Methods for Astrophysics;Astrophysics of Galaxies | 3,692Instrumentation and Methods for Astrophysics;Astrophysics of Galaxies
|
2011.14895 | Feed-forward ReLU neural networks partition their input domain into finitely
many "affine regions" of constant neuron activation pattern and affine
behaviour. We analyze their mathematical structure and provide algorithmic
primitives for an efficient application of linear programming related
techniques for iterative minimization of such non-convex functions. In
particular, we propose an extension of the Simplex algorithm which is iterating
on induced vertices but, in addition, is able to change its feasible region
computationally efficiently to adjacent "affine regions". This way, we obtain
the Barrodale-Roberts algorithm for LAD regression as a special case, but also
are able to train the first layer of neural networks with L1 training loss
decreasing in every step.
| [
"math.OC"
] | math.OC | Optimization and Control | 5,234Optimization and Control
|
|
1804.01105 | A gyrokinetic linear stability analysis of a collisionless slab geometry in
the local approximation is presented. We focus on $k_\parallel=0$ universal (or
entropy) modes driven by plasma gradients at small and large plasma $\beta$.
These are small scale non-MHD instabilities with growth rates that typically
peak near $k_\perp\rho_i\sim 1$ and vanish in the long wavelength $k_\perp\to
0$ limit. This work also discusses a mode known as the Gradient Drift Coupling
(GDC) instability previously reported in the gyrokinetic literature, which has
a finite growth rate $\gamma= \sqrt{\beta/[2(1+\beta)]} C_s/|L_p|$ with
$C_s^2=p_0/\rho_0$ for $k_\perp\to 0$ and is universally unstable for
$1/L_p\neq 0$. We show the GDC instability is a spurious, unphysical artifact
that erroneously arises due to the failure to respect the total equilibrium
pressure balance $p_0+B_0^2/(8\pi)=\text{constant}$, which renders the
assumption $B_0'=0$ inconsistent if $p_0'\neq 0$.
| [
"physics.plasm-ph"
] | physics.plasm-ph | Plasma Physics | 5,556Plasma Physics
|
|
1301.5760 | We find the spectrum of the Walsh-Hadamard type matrices defined by R.Adin
and Y.Roichman in their recent work on character formulas and descent sets for
the symmetric group.
| [
"math.CO"
] | math.CO | Combinatorics | 1,014Combinatorics
|
|
0807.1225 | We apply the Hilbert transform to the physics of internal waves in
two-dimensional fluids. Using this demodulation technique, we can discriminate
internal waves propagating in different directions: this is very helpful in
answering several fundamental questions in the context of internal waves. We
focus more precisely in this paper on phenomena associated with dissipation,
diffraction and reflection of internal waves.
| [
"physics.flu-dyn"
] | physics.flu-dyn | Fluid Dynamics | 2,452Fluid Dynamics
|
|
1802.04416 | Neural collaborative filtering (NCF) and recurrent recommender systems (RRN)
have been successful in modeling user-item relational data. However, they are
also limited in their assumption of static or sequential modeling of relational
data as they do not account for evolving users' preference over time as well as
changes in the underlying factors that drive the change in user-item
relationship over time. We address these limitations by proposing a Neural
Tensor Factorization (NTF) model for predictive tasks on dynamic relational
data. The NTF model generalizes conventional tensor factorization from two
perspectives: First, it leverages the long short-term memory architecture to
characterize the multi-dimensional temporal interactions on relational data.
Second, it incorporates the multi-layer perceptron structure for learning the
non-linearities between different latent factors. Our extensive experiments
demonstrate the significant improvement in rating prediction and link
prediction on dynamic relational data by our NTF model over both neural network
based factorization models and other traditional methods.
| [
"cs.LG"
] | cs.LG | Machine Learning | 3,882Machine Learning
|
|
0901.3954 | The interactions that can be introduced between a massless Rarita-Schwinger
field and an Abelian three-form gauge field in eleven spacetime dimensions are
analyzed in the context of the deformation of the free solution of the master
equation combined with local BRST cohomology. Under the hypotheses of
smoothness of the interactions in the coupling constant, locality, Poincare
invariance, Lorentz covariance, and the presence of at most two derivatives in
the Lagrangian of the interacting theory (the same number of derivatives like
in the free Lagrangian), we prove that there are neither cross-couplings nor
self-interactions for the gravitino in D=11.The only possible term that can be
added to the deformed solution to the master equation is nothing but a
generalized Chern-Simons term for the three-form gauge field, which brings
contributions to the deformed Lagrangian, but does not modify the original,
Abelian gauge transformations.
| [
"hep-th"
] | hep-th | High Energy Physics - Theory | 3,266High Energy Physics - Theory
|
|
2106.04645 | In this paper we present irradiation measurements performed to select a
transparent anode substrate that best meets the requirements of an optical
readout for a novel detector, the LaGEMPix. The modification of the optical
properties of the material due to proton irradiation were studied in soda-lime,
fused quartz and fused silica glasses coated with an Indium Tin Oxide layer.
The irradiations were performed using the research Beam Transfer Line (BTL) of
the IBA Cyclone 18 MeV cyclotron of the Bern University Hospital (Inselspital).
We recorded visible scintillation light generated by proton irradiation in the
soda-lime and fused quartz samples. We also investigated the darkening of these
three glasses and observed radiation-induced colour centres in the soda-lime
glass sample. The optical transmission spectra of the samples were measured
before and after irradiation. Reductions of 45%, 1% and 0.4% were observed for
soda-lime glass, fused quartz and fused silica, respectively (with an
associated error of 0.25%). We conclude that the best option for our specific
application is the fused silica substrate, which will be the transparent anode
for the next generation of the LaGEMPix detector.
| [
"physics.ins-det",
"physics.app-ph",
"physics.med-ph"
] | physics.ins-det | physics.app-ph | Instrumentation and Detectors;Applied Physics;Medical Physics | 7,267longtail
|
1209.4563 | In the presence of a rotating Kerr black hole, we investigate hydrodynamics
of the massive particles and massless photons, to construct relations among
number density, pressure and internal energy density of the massive particles
and photons around the rotating Kerr black hole and to study an accretion onto
the black hole. On equatorial plane of the Kerr black hole, we investigate the
bound orbits of the massive particles and photons around the black hole to
produce their radial, azimuthal and precession frequencies. With these
frequencies we study the black holes GRO~J1655-40 and 4U~1543-47, to explicitly
obtain the radial, azimuthal and precession frequencies of the massive
particles in the flow of perfect fluid. We next consider the massive particles
in the stable circular orbit of radius of $1.0~ly$ around the supernovas SN
1979C, SN 1987A and SN 2213-1745 in the Kerr curved spacetime, and around the
potential supermassive Schwarzschild black holes M87, NGC 3115, NGC 4594, NGC
3377, NGC 4258, M31, M32 and Galatic center, to estimate their radial and
azimuthal frequencies, which are shown to be the same results as those in no
precession motion. The photon unstable orbit is also discussed in terms of the
impact parameter of the photon trajectory. Finally, on the equatorial plane of
the Kerr black hole, we construct the global flat embedding structures
possessing (9+3) dimensionalities outside and inside the event horizon of the
rotating Kerr black hole. Moreover, on the plane we investigate the warp
products of the Kerr spacetime.
| [
"gr-qc"
] | gr-qc | General Relativity and Quantum Cosmology | 2,674General Relativity and Quantum Cosmology
|
|
cond-mat/9904070 | In the case of a system with an unbounded hamiltonian the entropic index q of
non-extensive thermodynamics has an upperbound q_c>1 beyond which the formalism
becomes meaningless. The expression 1/(q_c-1) is the dimension of the state
space (i.e. the manifold of density matrices) in the context of non-commutative
geometry. For q=q_c an ultraviolet cutoff E< E_ub is needed to guarantee the
existence of the equilibrium density matrix. Duality between q>1 and
q<1-statistics via a q --> 1/q transformation is established. It leads to an
overall picture in which the meaning of both q>1-statistics and q<1-statistics
is clarified.
| [
"cond-mat.stat-mech"
] | cond-mat.stat-mech | Statistical Mechanics | 6,821Statistical Mechanics
|
|
2004.06232 | We establish the triple integral evaluation \[ \int_{1}^{\infty} \int_{0}^{1}
\int_{0}^{1} \frac{dz \, dy \, dx}{x(x+y)(x+y+z)}
= \frac{5}{24} \zeta(3), \] as well as the equivalent polylogarithmic double
sum \[ \sum_{k=1}^{\infty} \sum_{j=k}^{\infty} \frac{(-1)^{k-1}}{k^{2}} \,
\frac{1}{j \, 2^{j}}
= \frac{13}{24} \zeta(3). \] This double sum is related to, but less
approachable than, similar sums studied by Ramanujan. It is also reminiscent of
Euler's formula $\zeta(2,1) = \zeta(3)$, which is the simplest instance of
duality of multiple polylogarithms. We review this duality and apply it to
derive a companion identity. We also discuss approaches based on computer
algebra. All of our approaches ultimately require the introduction of
polylogarithms and nontrivial relations between them. It remains an open
challenge to relate the triple integral or the double sum to $\zeta(3)$
directly.
| [
"math.NT",
"math.CA"
] | math.NT | math.CA | Number Theory;Classical Analysis and ODEs | 4,958Number Theory;Classical Analysis and ODEs
|
cond-mat/0202401 | A generally applicable model is presented to describe the potential barrier
shape in ultra small Schottky diodes. It is shown that for diodes smaller than
a characteristic length $l_c$ (associated with the semiconductor doping level)
the conventional description no longer holds. For such small diodes the
Schottky barrier thickness decreases with decreasing diode size. As a
consequence, the resistance of the diode is strongly reduced, due to enhanced
tunneling. Without the necessity of assuming a reduced (non-bulk) Schottky
barrier height, this effect provides an explanation for several experimental
observations of enhanced conduction in small Schottky diodes.
| [
"cond-mat"
] | cond-mat | Condensed Matter | 1,697Condensed Matter
|
|
0708.0140 | We present extensive optical (UBVRI), near-infrared (JK) light curves and
optical spectroscopy of the Type Ia supernova (SN) 2006X in the nearby galaxy
NGC 4321 (M100). Our observations suggest that either SN 2006X has an
intrinsically peculiar color evolution, or it is highly reddened [E(B -
V)_{host} = 1.42+/-0.04 mag] with R_V = 1.48+/-0.06, much lower than the
canonical value of 3.1 for the average Galactic dust. SN 2006X also has one of
the highest expansion velocities ever published for a SN Ia. Compared with the
other SNe Ia we analyzed, SN 2006X has a broader light curve in the U band, a
more prominent bump/shoulder feature in the V and R bands, a more pronounced
secondary maximum in the I and near-infrared bands, and a remarkably smaller
late-time decline rate in the B band. The B - V color evolution shows an
obvious deviation from the Lira-Phillips relation at 1 to 3 months after
maximum brightness. At early times, optical spectra of SN 2006X displayed
strong, high-velocity features of both intermediate-mass elements (Si, Ca, and
S) and iron-peak elements, while at late times they showed a relatively blue
continuum, consistent with the blue U-B and B-V colors at similar epochs. A
light echo and/or the interaction of the SN ejecta and its circumstellar
material may provide a plausible explanation for its late-time photometric and
spectroscopic behavior. Using the Cepheid distance of M100, we derive a Hubble
constant of 72.7+/-8.2 km s^{-1} Mpc^{-1}(statistical) from the normalized
dereddened luminosity of SN 2006X. We briefly discuss whether abnormal dust is
a universal signature for all SNe Ia, and whether the most rapidly expanding
objects form a subclass with distinct photometric and spectroscopic properties.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
2011.11139 | In the second part of this paper, we develop a centralized packet
transmission scheduling scheme to pair with the protocol designed in Part I and
complete our medium access control (MAC) design for machine-type communications
in the industrial internet of things. For the networking scenario, fine-grained
scheduling that attends to each device becomes necessary, given stringent
quality of service (QoS) requirements and diversified service types, but
prohibitively complex for a large number of devices. To address this challenge,
we propose a scheduling solution in two steps. First, we develop algorithms for
device assignment based on the analytical results from Part I, when parameters
of the proposed protocol are given. Then, we train a deep neural network for
assisting in the determination of the protocol parameters. The two-step
approach ensures the accuracy and granularity necessary for satisfying the QoS
requirements and avoids excessive complexity from handling a large number of
devices. Integrating the distributed coordination in the protocol design from
Part I and the centralized scheduling from this part, the proposed MAC protocol
achieves high performance, demonstrated through extensive simulations. For
example, the results show that the proposed MAC can support 1000 devices under
an aggregated traffic load of 3000 packets per second with a single channel and
achieve <0.5ms average delay and <1% average collision probability among 50
high priority devices.
| [
"cs.NI",
"cs.SY",
"eess.SY"
] | cs.NI | cs.SY | Networking and Internet Architecture;Systems and Control;Systems and Control | 4,759Networking and Internet Architecture;Systems and Control;Systems and Control
|
hep-ph/9205203 | A realistic technicolor model is presented with the dynamics below $150$ TeV
treated explicitly. Electroweak symmetry is broken by the condensates of a
`minimal' doublet of technifermions. The new feature of the model is that the
the third generation quarks are unified with the technifermions into multiplets
of a walking gauge force down to a scale of $10$ TeV. The remaining quarks and
leptons are not involved in this unification however. The walking dynamics
enhances the higher dimension interactions which give the ordinary fermions
their masses and mixing, while leaving flavor-changing neutral currents
suppressed. Because the third generation quarks actually feel the walking force
their masses can be much larger than those of the other quarks and the leptons.
The only non-standard particles with masses below several TeV are the single
doublet of technifermions, so electroweak radiative corrections are estimable
and within experimental limits.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
hep-ph/9910287 | We consider single charged Higgs ($H^{\pm}$) and pseudoscalar Higgs ($A^0$)
production in association with a gauge boson at $\mu^+\mu^-$ colliders. We find
that the tree-level t-channel and s-channel contributions to $\mu^+\mu^-\to
H^{\pm}W^{\mp}, A^0Z$ are enhanced for large values of $\tan\beta$, allowing
sizeable cross-sections whose analogies at $e^+e^-$ colliders would be very
small. These processes provide attractive new ways of producing such particles
at $\mu^+\mu^-$ colliders and are superior to the conventional methods in
regions of parameter space.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
1909.01312 | A continuous stroking sensation on the skin can convey messages or emotion
cues. We seek to induce this sensation using a combination of illusory motion
and lateral stroking via a haptic device. Our system provides discrete lateral
skin-slip on the forearm with rotating tactors, which independently provide
lateral skin-slip in a timed sequence. We vary the sensation by changing the
angular velocity and delay between adjacent tactors, such that the apparent
speed of the perceived stroke ranges from 2.5 to 48.2 cm/s. We investigated
which actuation parameters create the most pleasant and continuous sensations
through a user study with 16 participants. On average, the sensations were
rated by participants as both continuous and pleasant. The most continuous and
pleasant sensations were created by apparent speeds of 7.7 and 5.1 cm/s,
respectively. We also investigated the effect of spacing between contact points
on the pleasantness and continuity of the stroking sensation, and found that
the users experience a pleasant and continuous linear sensation even when the
space between contact points is relatively large (40 mm). Understanding how
sequential discrete lateral skin-slip creates continuous linear sensations can
influence the design and control of future wearable haptic devices.
| [
"cs.HC",
"cs.RO"
] | cs.HC | cs.RO | Human-Computer Interaction;Robotics | 3,515Human-Computer Interaction;Robotics
|
2401.00543 | Fix a positive integer $n$, a real number $p\in (0,1]$, and a (perhaps
random) hypergraph $\mathcal{H}$ on $[n]$. We introduce and investigate the
following random multigraph model, which we denote $\mathbb{G}(n,p\, ;
\,\mathcal{H})$: begin with an empty graph on $n$ vertices, which are labelled
by the set $[n]$. For every $H\in \mathcal{H}$ choose, independently from
previous choices, a doubleton from $H$, say $D = \{i,j\} \subset H$, uniformly
at random and then introduce an edge between the vertices $i$ and $j$ in the
graph with probability $p$, where each edge is introduced independently of all
other edges.
| [
"math.CO",
"cs.DM",
"math.PR"
] | math.CO | cs.DM | Combinatorics;Discrete Mathematics;Probability | 1,061Combinatorics;Discrete Mathematics;Probability
|
0705.2916 | The problem of the time is one of the open issues in the quantum gravity.
This problem is particular problem in the canonical quantum gravity. Even in
the loop gravity the problem of the time remain. Our work is concerning to the
problem of the time. The Wheeler-DeWitt itself contains time evolution part,
but which part is the time evolution part is open issue. However, we can create
a method that seems to solve this problem that is up-to-down method created in
the previous works. We can derive equation relating to the time and static
restriction in this paper. As a example we treat the problem of the time of the
Friedmann universe. And we derive the static restriction in quantum gravity.
| [
"gr-qc",
"hep-th"
] | gr-qc | hep-th | General Relativity and Quantum Cosmology;High Energy Physics - Theory | 2,746General Relativity and Quantum Cosmology;High Energy Physics - Theory
|
2301.05182 | In this work, we initiate the idea of using denoising diffusion models to
learn priors for online decision making problems. Our special focus is on the
meta-learning for bandit framework, with the goal of learning a strategy that
performs well across bandit tasks of a same class. To this end, we train a
diffusion model that learns the underlying task distribution and combine
Thompson sampling with the learned prior to deal with new tasks at test time.
Our posterior sampling algorithm is designed to carefully balance between the
learned prior and the noisy observations that come from the learner's
interaction with the environment. To capture realistic bandit scenarios, we
also propose a novel diffusion model training procedure that trains even from
incomplete and/or noisy data, which could be of independent interest. Finally,
our extensive experimental evaluations clearly demonstrate the potential of the
proposed approach.
| [
"cs.LG",
"cs.AI",
"stat.ML"
] | cs.LG | cs.AI | Machine Learning;Artificial Intelligence;Machine Learning | 3,951Machine Learning;Artificial Intelligence;Machine Learning
|
1208.2363 | We study dynamic minimization problems of the calculus of variations with
Lagrangian functionals containing Riemann-Liouville fractional integrals,
classical and Caputo fractional derivatives. Under assumptions of regularity,
coercivity and convexity, we prove existence of solutions.
| [
"math.OC"
] | math.OC | Optimization and Control | 5,234Optimization and Control
|
|
1207.4251 | Two dimensional electronic spectroscopy and transient grating measurements
were performed, for the first time, on nitrogen-vacancy centers in diamond.
These measurements reveal energy transfer and vibrational pathways with
consequences for spin coherence.
| [
"cond-mat.mes-hall",
"quant-ph"
] | cond-mat.mes-hall | quant-ph | Mesoscale and Nanoscale Physics;Quantum Physics | 4,536Mesoscale and Nanoscale Physics;Quantum Physics
|
1701.06859 | The representation of images in the brain is known to be sparse. That is, as
neural activity is recorded in a visual area ---for instance the primary visual
cortex of primates--- only a few neurons are active at a given time with
respect to the whole population. It is believed that such a property reflects
the efficient match of the representation with the statistics of natural
scenes. Applying such a paradigm to computer vision therefore seems a promising
approach towards more biomimetic algorithms. Herein, we will describe a
biologically-inspired approach to this problem. First, we will describe an
unsupervised learning paradigm which is particularly adapted to the efficient
coding of image patches. Then, we will outline a complete multi-scale framework
---SparseLets--- implementing a biologically inspired sparse representation of
natural images. Finally, we will propose novel methods for integrating prior
information into these algorithms and provide some preliminary experimental
results. We will conclude by giving some perspective on applying such
algorithms to computer vision. More specifically, we will propose that
bio-inspired approaches may be applied to computer vision using predictive
coding schemes, sparse models being one simple and efficient instance of such
schemes.
| [
"cs.CV",
"q-bio.NC"
] | cs.CV | q-bio.NC | Computer Vision and Pattern Recognition;Neurons and Cognition | 1,629Computer Vision and Pattern Recognition;Neurons and Cognition
|
0912.0745 | The objective of this paper is to understand the critical parameters that
need to be addressed while designing a guitar tuner. The focus of the design
lies in developing a suitable algorithm to accurately detect the fundamental
frequency of a plucked guitar string from its frequency spectrum. A
userfriendly graphical interface is developed using Matlab to allow any user to
easily tune his guitar using the developed program.
| [
"cs.SD"
] | cs.SD | Sound | 6,724Sound
|
|
nlin/0510012 | We present a numerical method that allows a formation of communicating agents
to target the boundary of a time dependent concentration by following a time
dependent concentration gradient. The algorithm motivated by \cite{MB, BKM},
allows the agents to move in space in a non-stationary environment. Our method
is applicable to finding the boundary of any regular surface and may be of
interest for for studying motions of swarms in biology, as well as to
engineering applications where boundary detection is an issue.
| [
"nlin.PS",
"nlin.AO"
] | nlin.PS | nlin.AO | Pattern Formation and Solitons;Adaptation and Self-Organizing Systems | 5,408Pattern Formation and Solitons;Adaptation and Self-Organizing Systems
|
1101.4949 | Systematic variations in 54Cr/52Cr ratios between meteorite classes (Qin et
al., 2010a; Trinquier et al., 2007) point to large scale spatial and/or
temporal isotopic heterogeneity in the solar protoplanetary disk. Two
explanations for these variations have been proposed, with important
implications for the formation of the Solar System: heterogeneous seeding of
the disk with dust from a supernova, or energetic-particle irradiation of dust
in the disk. The key to differentiating between them is identification of the
carrier(s) of the 54Cr anomalies. Here we report the results of our recent
NanoSIMS imaging search for the 54Cr-rich carrier in the acid-resistant residue
of the CI chondrite Orgueil. A total of 10 regions with extreme 54Cr-excesses
({\delta}54Cr values up to 1500 %) were found. Comparison between SEM, Auger
and NanoSIMS analyses showed that these 54Cr-rich regions are associated with
one or more sub-micron (typically less than 200 nm) Cr oxide grains, most
likely spinels. Because the size of the NanoSIMS primary O- ion beam is larger
than the typical grain size on the sample mount, the measured anomalies are
lower limits, and we estimate that the actual 54Cr enrichments in three grains
are at least 11 times Solar and in one of these may be as high as 50 times
Solar. Such compositions strongly favor a Type II supernova origin. The
variability in bulk 54Cr/52Cr between meteorite classes argues for a
heterogeneous distribution of the 54Cr carrier in the solar protoplanetary disk
following a late supernova injection event. Such a scenario is also supported
by the O-isotopic distribution and variable abundances in different planetary
materials of other presolar oxide and silicate grains from supernovae.
| [
"astro-ph.EP"
] | astro-ph.EP | Earth and Planetary Astrophysics | 2,351Earth and Planetary Astrophysics
|
|
1405.4694 | We re-investigate the magnetically frustrated, {\it
diamond-lattice-antiferromagnet} spinels FeAl$_2$O$_4$ and MnAl$_2$O$_4$ using
magnetization measurements and diffuse scattering of polarized neutrons. In
FeAl$_2$O$_4$, macroscopic measurements evidence a "cusp" in zero field-cooled
susceptibility around 13~K. Dynamic magnetic susceptibility and {\it memory
effect} experiments provide results that do not conform with a canonical
spin-glass scenario in this material. Through polarized neutron scattering
studies, absence of long-range magnetic order down to 4~K is confirmed in
FeAl$_2$O$_4$. By modeling the powder averaged differential magnetic neutron
scattering cross-section, we estimate that the spin-spin correlations in this
compound extend up to the third nearest-neighbour shell. The estimated value of
the Land\'{e} $g$ factor points towards orbital contributions from Fe$^{2+}$.
This is also supported by a Curie-Weiss analysis of the magnetic
susceptibility. MnAl$_2$O$_4$, on the contrary, undergoes a magnetic phase
transition into a long-range ordered state below $\approx$ 40~K, which is
confirmed by macroscopic measurements and polarized neutron diffraction.
However, the polarized neutron studies reveal the existence of prominent
spin-fluctuations co-existing with long-range antiferromagnetic order. The
magnetic diffuse intensity suggests a similar short range order as in
FeAl$_2$O$_4$. Results of the present work supports the importance of spin-spin
correlations in understanding magnetic response of frustrated magnets like
$A$-site spinels which have predominant short-range spin correlations
reminiscent of the "spin liquid" state.
| [
"cond-mat.dis-nn",
"cond-mat.str-el"
] | cond-mat.dis-nn | cond-mat.str-el | Disordered Systems and Neural Networks;Strongly Correlated Electrons | 2,190Disordered Systems and Neural Networks;Strongly Correlated Electrons
|
1706.01039 | Age progression is defined as aesthetically re-rendering the aging face at
any future age for an individual face. In this work, we aim to automatically
render aging faces in a personalized way. Basically, for each age group, we
learn an aging dictionary to reveal its aging characteristics (e.g., wrinkles),
where the dictionary bases corresponding to the same index yet from two
neighboring aging dictionaries form a particular aging pattern cross these two
age groups, and a linear combination of all these patterns expresses a
particular personalized aging process. Moreover, two factors are taken into
consideration in the dictionary learning process. First, beyond the aging
dictionaries, each person may have extra personalized facial characteristics,
e.g. mole, which are invariant in the aging process. Second, it is challenging
or even impossible to collect faces of all age groups for a particular person,
yet much easier and more practical to get face pairs from neighboring age
groups. To this end, we propose a novel Bi-level Dictionary Learning based
Personalized Age Progression (BDL-PAP) method. Here, bi-level dictionary
learning is formulated to learn the aging dictionaries based on face pairs from
neighboring age groups. Extensive experiments well demonstrate the advantages
of the proposed BDL-PAP over other state-of-the-arts in term of personalized
age progression, as well as the performance gain for cross-age face
verification by synthesizing aging faces.
| [
"cs.CV"
] | cs.CV | Computer Vision and Pattern Recognition | 1,498Computer Vision and Pattern Recognition
|
|
2108.11475 | The Permutation Pattern Matching problem asks, given two permutations
$\sigma$ on $n$ elements and $\pi$, whether $\sigma$ admits a subsequence with
the same relative order as $\pi$ (or, in the counting version, how many such
subsequences are there). This natural problem was shown by Bose, Buss and Lubiw
[IPL 1998] to be NP-complete, and hence we should seek exact exponential time
solutions. The asymptotically fastest such solution up to date, by Berendsohn,
Kozma and Marx [IPEC 2019], works in $\mathcal{O}(1.6181^n)$ time. We design a
simple and faster $\mathcal{O}(1.415^{n})$ time algorithm for both the
detection and the counting version. We also prove that this is optimal among a
certain natural class of algorithms.
| [
"cs.DS"
] | cs.DS | Data Structures and Algorithms | 1,908Data Structures and Algorithms
|
|
1101.3531 | We present the results of infrared (IR; 2.5--160 um) observations of the
supernova remnant (SNR) Kes 17 based on the data obtained with the AKARI and
Spitzer satellites. We first detect bright continuum emission of its western
shell in the mid- and far-IR wavebands together with its near-IR molecular line
emission. We also detect hidden mid-IR emission of its southern shell after
subtraction of the background emission in this region. The far-IR luminosity of
the western shell is ~ 8100 L_sun, which makes Kes 17 one of the few SNRs of
significant far-IR emission. The fittings of the spectral energy distribution
indicate the existence of two dust components: ~ 79 K (hot) and ~ 27 K (cold)
corresponding to the dust mass of ~ 6.2x10^{-4} M_sun and ~ 6.7 M_sun,
respectively. We suggest that the hot component represents the dust emission of
the material swept up by the SNR to its western and southern boundaries,
compatible with the distribution of radio continuum emission overlapping the
mid-IR emission in the western and southern shells. The existence of hot (~
2,000 K), shocked dense molecular gas revealed by the near-IR molecular line
emission in the western shell, on the other hand, suggests that the cold dust
component represents the dust emission related to the interaction between the
SNR and nearby molecular gas. The excitation conditions of the molecular gas
appear to be consistent with those from shocked, clumpy admixture gas of
different temperatures. We discuss three possibilities for the origin of the
bright far-IR emission of the cold dust in the western shell: the emission of
dust in the inter-clump medium of shocked molecular clouds, the emission of
dust in evaporating flows of molecular clouds engulfed by hot gas, and the
emission of dust of nearby molecular clouds illuminated by radiative shocks.
| [
"astro-ph.GA"
] | astro-ph.GA | Astrophysics of Galaxies | 464Astrophysics of Galaxies
|
|
2307.16423 | Currently, the world has been facing the brunt of a pandemic due to a disease
called COVID-19 for the last 2 years. To study the spread of such infectious
diseases it is important to not only understand their temporal evolution but
also the spatial evolution. In this work, the spread of this disease has been
studied with a cellular automata (CA) model to find the temporal and the
spatial behavior of it. Here, we have proposed a neighborhood criteria which
will help us to measure the social confinement at the time of the disease
spread. The two main parameters of our model are (i) disease transmission
probability (q) which helps us to measure the infectivity of a disease and (ii)
exponent (n) which helps us to measure the degree of the social confinement.
Here, we have studied various spatial growths of the disease by simulating this
CA model. Finally we have tried to fit our model with the COVID-19 data of
India for various waves and have attempted to match our model predictions with
regards to each wave to see how the different parameters vary with respect to
infectivity and restrictions in social interaction.
| [
"physics.bio-ph",
"nlin.CG",
"physics.comp-ph"
] | physics.bio-ph | nlin.CG | Biological Physics;Cellular Automata and Lattice Gases;Computational Physics | 7,267longtail
|
2105.01552 | Subsampling methods aim to select a subsample as a surrogate for the observed
sample. As a powerful technique for large-scale data analysis, various
subsampling methods are developed for more effective coefficient estimation and
model prediction. This review presents some cutting-edge subsampling methods
based on the large-scale least squares estimation. Two major families of
subsampling methods are introduced, respectively, the randomized subsampling
approach and the optimal subsampling approach. The former aims to develop a
more effective data-dependent sampling probability, while the latter aims to
select a deterministic subsample in accordance with certain optimality
criteria. Real data examples are provided to compare these methods empirically,
respecting both the estimation accuracy and the computing time.
| [
"stat.ME"
] | stat.ME | Methodology | 4,557Methodology
|
|
physics/0008235 | The emergence of CsCl bulk structure in (CsCl)nCs+ cluster ions is
investigated using a mixed quantum-mechanical/semiempirical theoretical
approach. We find that rhombic dodecahedral fragments (with bulk CsCl symmetry)
are more stable than rock-salt fragments after the completion of the fifth
rhombic dodecahedral atomic shell. From this size (n=184) on, a new set of
magic numbers should appear in the experimental mass spectra. We also propose
another experimental test for this transition, which explicitely involves the
electronic structure of the cluster. Finally, we perform more detailed
calculations in the size range n=31--33, where recent experimental
investigations have found indications of the presence of rhombic dodecahedral
(CsCl)32Cs+ isomers in the cluster beams.
| [
"physics.atm-clus"
] | physics.atm-clus | Atomic and Molecular Clusters | 624Atomic and Molecular Clusters
|
|
astro-ph/0509764 | We have investigated the abundance of calcium in early-type galaxies by
measuring the strength of the Ca I 4227 absorption line in their integrated
spectra. The database used is the large sample of early-type galaxy integrated
spectra in Caldwell, Rose, & Concannon (2003). We have measured Ca abundances
from the Ca I 4227 feature both by using the Lick Ca4227 index and also by
defining a new index, Ca4227_r, that avoids the CN4216 molecular band in the
continuum on the blueward side of the line. With the new index definition we
measure Ca abundances that are systematically ~0.3 dex higher than with the
Lick Ca4227 index. The result is that with the new index definition we obtain
higher [Ca/Fe] abundances in early-type galaxies which are more consistent with
their well known [Mg/Fe] over-abundances. Hence, we suggest that Ca might be
slightly enhanced, relative to Fe, in early-type galaxies.
| [
"astro-ph"
] | astro-ph | Astrophysics | 463Astrophysics
|
|
0907.4384 | Let D(n) be the set of all fractions in the unit interval whose denominator
in lowest terms equals $n$. We evaluate the product of the values of the Gamma
function at the points of D(n), as a function of $n$; the answer depends on
whether or not $n$ is a prime power.
| [
"math.CA",
"math.NT"
] | math.CA | math.NT | Classical Analysis and ODEs;Number Theory | 970Classical Analysis and ODEs;Number Theory
|
1102.1055 | In this paper, we classify the singular parameters for the
Birman-Murakami-Wenzl algebra over an arbitrary field. Equivalently, we give a
criterion for the Birman-Murakami-Wenzl algebra being Morita equivalent to the
direct sum of the Hecke algebras associated to certain symmetric groups.
| [
"math.QA"
] | math.QA | Quantum Algebra | 5,873Quantum Algebra
|
|
1409.8355 | We use a sample of over 5000 active galactic nuclei (AGN) with extended
morphologies at z<0.8 from the Sloan Digital Sky Survey (SDSS) to study the
ensemble optical variability as a function of rest-frame time lag and AGN
luminosity with the aim of investigating these parameter relationships at lower
luminosities than previously studied. We compare photometry from imaging data
with spectrophotometry obtained weeks to years later in the Sloan g, r, and i
bands. We employ quasar and galaxy eigenspectra fitting to separate the AGN and
host galaxy components. A strong correlation between the variability amplitude
and rest-frame time lag is observed, in agreement with quasar structure
functions but extending to AGN several magnitudes fainter than previously
studied. The structure function slopes for our fainter AGN sample are slightly
shallower than those found in quasars studies. An anticorrelation with
luminosity is clearly detected, with lower luminosity AGN displaying greater
variability amplitudes. We demonstrate for the first time that this
anticorrelation extends to AGN as faint as $M_{AGN_i}\sim-18.5$, with a slight
trend towards shallower slopes at luminosities fainter than
$M_{AGN_i}\sim-20.2$.
| [
"astro-ph.GA",
"astro-ph.CO"
] | astro-ph.GA | astro-ph.CO | Astrophysics of Galaxies;Cosmology and Nongalactic Astrophysics | 470Astrophysics of Galaxies;Cosmology and Nongalactic Astrophysics
|
cond-mat/9905018 | The understanding of an electron gas with short coherence length pairs formed
by an attractive interaction is believed to be one of the major keys to our
theoretical knowledge of the high-T_c-superconductors. Mainly the deviations of
the cuprates from usual metallic Fermi liquid behaviour already in the normal
state like e.g. a linear resistivity or the observation of a pseudo gap can
result from electron-electron correlations.
We therefore investigate the negative U Hubbard model in two dimensions at
low densities using the T-matrix approximation. In the non selfconsistent
formulation of the theory the system always shows an instability towards Bose
condensation of pairs into an infinite lifetime two-particle bound state. If
the calculations are performed selfconsistently pair-pair scattering is
included which causes the pairs to have finite lifetime. The physics of these
finite lifetime pairs is discussed.
| [
"cond-mat.str-el",
"cond-mat.supr-con"
] | cond-mat.str-el | cond-mat.supr-con | Strongly Correlated Electrons;Superconductivity | 7,053Strongly Correlated Electrons;Superconductivity
|
0901.0863 | The lepton-number-violating decays of $B^+, D^+$ and $D_s^+$ mesons induced
by the doubly charged Higgs boson have been studied. It is found that although
the yielded results of the branch ratio are much smaller than the present
limits from the data they are consistent with the previous conclusions
calculated in the framwork of relativistic quark model where the processes
happened via the light Majorana neutrinos.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
1711.04275 | Magnetic proximity effect of a topological insulator in contact with a
ferromagnet is reported in thin film bilayers of 15 nm thick $BiSbTe_3$ on
either 15 or 40 nm thick $SrRuO_3$ on (100) $SrTiO_3$ wafers. Magneto transport
results of the bilayers were compared with those of reference films of 15 nm
$BiSbTe_3$ and 15 or 40 nm $SrRuO_3$. Comparison of the temperature coefficient
of resistance [(1/R)$\times$dR/dT which is qualitatively proportional to the
magnetization] of the bilayer and reference ferromagnetic film normalized above
$T_c$, shows a clear suppression in the bilayer by about 50% just below $T_c$,
indicating a weaker proximity magnetization in the bilayer. Resistance
hysteresis loops versus field at 1.85$\pm$0.05 K in the bilayer and reference
films show a clear magnetic proximity effect, where the peak resistance of the
bilayer at the coercive field shifts to lower fields by $\sim$30% compared to a
hypothetical bilayer of two resistors connected in parallel with no interaction
between the layers. Narrowing of the coercive peaks of the bilayers as compared
to those of the reference ferromagnetic films by 25-35% was also observed,
which represents another signature of the magnetic proximity effect.
| [
"cond-mat.str-el"
] | cond-mat.str-el | Strongly Correlated Electrons | 6,979Strongly Correlated Electrons
|
|
0809.4712 | This paper discusses some aspects of PHOBOS physics and its origins, in
particular participant scaling and extended longitudinal scaling, seen in A+A
and h+A collisions at all energies.
| [
"nucl-ex"
] | nucl-ex | Nuclear Experiment | 4,855Nuclear Experiment
|
|
hep-ph/0111144 | In the framework of minimal supersymmetric model we examine the Z-peak
constraints on the scenario of one light sbottom (2--5.5 GeV) and light gluino
(12--16 GeV), which has been successfully used to explain the excess of bottom
quark production in hadron collision. Such a scenario is found to be severely
constrained by LEP Z-peak observables, especially by R_b, due to the large
effect of gluino-sbottom loops. To account for the R_b data in this scenario,
the other mass eigenstate of sbottom, i.e., the heavier one, must be lighter
than 125 (195) GeV at 2-sigma (3-sigma) level, which should have been produced
in association with the lighter one at LEP II and will probobaly be within the
reach of Tevatron Run 2.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
2106.08231 | In this paper, we consider a single top quark production in association with
a neutral gauge boson (Z boson or Photon) at the future electron-positron
colliders. We utilize these channels to probe the top quark Flavour Changing
Neutral Currents (FCNC) interactions in $tqZ$ and $tq\gamma$ vertices. We
perform two separate analyses for top-Z-jet and top-$\gamma$-jet channels. The
Standard Model Effective Field Theory (SMEFT) approach is employed to search
for these anomalous couplings. We consider parton showering, hadronization and
fast detector simulation in our study and use a cut-and-count technique to
separate the signal from the Standard Model (SM) background processes. The
upper limits on the FCNC couplings at $95\%$ confidence level for the different
integrated luminosities are obtained. It is shown that the future lepton
collider would be able to probe the FCNC branching fractions to
$\rm{Br}(t\rightarrow q \gamma)< 10^{-4}$ and $\rm{Br}(t\rightarrow q Z) <
10^{-4}$ with $3$ $\rm{ab}^{-1}$of integrated luminosity of data at a center of
mass energy of $350$ GeV.
| [
"hep-ph"
] | hep-ph | High Energy Physics - Phenomenology | 3,129High Energy Physics - Phenomenology
|
|
1911.06404 | LSST has chosen Kubernetes as the platform for deploying and operating the
LSST Science Platform. We first present the background reasoning behind this
decision, including both instrument-agnostic as well as LSST-specific
requirements. We then discuss the basic principles of Kubernetes and Helm, and
how they are used as the deployment base for the LSST Science Platform.
Furthermore, we provide an example of how an external group may use these
publicly available software resources to deploy their own instance of the LSST
Science Platform, and customize it to their needs. Finally, we discuss how more
astronomy software can follow these patterns to gain similar benefits.
| [
"astro-ph.IM"
] | astro-ph.IM | Instrumentation and Methods for Astrophysics | 3,689Instrumentation and Methods for Astrophysics
|
|
2303.12115 | Online social media foster the creation of active communities around shared
narratives. Such communities may turn into incubators for conspiracy theories
-- some spreading violent messages that could sharpen the debate and
potentially harm society. To face these phenomena, most social media platforms
implemented moderation policies, ranging from posting warning labels up to
deplatforming, i.e., permanently banning users. Assessing the effectiveness of
content moderation is crucial for balancing societal safety while preserving
the right to free speech. In this paper, we compare the shift in behavior of
users affected by the ban of two large communities on Reddit, GreatAwakening
and FatPeopleHate, which were dedicated to spreading the QAnon conspiracy and
body-shaming individuals, respectively. Following the ban, both communities
partially migrated to Voat, an unmoderated Reddit clone. We estimate how many
users migrate, finding that users in the conspiracy community are much more
likely to leave Reddit altogether and join Voat. Then, we quantify the
behavioral shift within Reddit and across Reddit and Voat by matching common
users. Few migrating zealots drive the growth of the new GreatAwakening
community on Voat, while this effect is absent for FatPeopleHate. Finally,
conspiracy users migrating from Reddit tend to recreate their previous social
network on Voat. Our findings suggest that banning conspiracy communities
hosting violent content should be carefully designed, as these communities may
be more resilient to deplatforming.
| [
"physics.soc-ph",
"cs.CY",
"cs.SI"
] | physics.soc-ph | cs.CY | Physics and Society;Computers and Society;Social and Information Networks | 5,482Physics and Society;Computers and Society;Social and Information Networks
|
math/0511230 | Motivated by the supersymmetric extension of Liouville theory in the recent
physics literature, we couple the standard Liouville functional with a spinor
field term. The resulting functional is conformally invariant. We study
geometric and analytic aspects of the resulting Euler-Lagrange equations,
culminating in a blow up analysis.
| [
"math.DG",
"math.AP"
] | math.DG | math.AP | Differential Geometry;Analysis of PDEs | 2,022Differential Geometry;Analysis of PDEs
|
1310.6331 | Adaptive stepsize control is a critical feature for the robust and efficient
numerical solution of initial-value problems in ordinary differential
equations. In this paper, we show that adaptive stepsize control can be
incorporated within a family of parallel time integrators known as Revisionist
Integral Deferred Correction (RIDC) methods. The RIDC framework allows for
various strategies to implement stepsize control, and we report results from
exploring a few of them.
| [
"math.NA"
] | math.NA | Numerical Analysis | 5,002Numerical Analysis
|
|
2206.14866 | The capability of generating speech with specific type of emotion is desired
for many applications of human-computer interaction. Cross-speaker emotion
transfer is a common approach to generating emotional speech when speech with
emotion labels from target speakers is not available for model training. This
paper presents a novel cross-speaker emotion transfer system, named iEmoTTS.
The system is composed of an emotion encoder, a prosody predictor, and a timbre
encoder. The emotion encoder extracts the identity of emotion type as well as
the respective emotion intensity from the mel-spectrogram of input speech. The
emotion intensity is measured by the posterior probability that the input
utterance carries that emotion. The prosody predictor is used to provide
prosodic features for emotion transfer. The timber encoder provides
timbre-related information for the system. Unlike many other studies which
focus on disentangling speaker and style factors of speech, the iEmoTTS is
designed to achieve cross-speaker emotion transfer via disentanglement between
prosody and timbre. Prosody is considered as the main carrier of
emotion-related speech characteristics and timbre accounts for the essential
characteristics for speaker identification. Zero-shot emotion transfer, meaning
that speech of target speakers are not seen in model training, is also realized
with iEmoTTS. Extensive experiments of subjective evaluation have been carried
out. The results demonstrate the effectiveness of iEmoTTS as compared with
other recently proposed systems of cross-speaker emotion transfer. It is shown
that iEmoTTS can produce speech with designated emotion type and controllable
emotion intensity. With appropriate information bottleneck capacity, iEmoTTS is
able to effectively transfer emotion information to a new speaker. Audio
samples are publicly available https://patrick-g-zhang.github.io/iemotts/
| [
"eess.AS",
"cs.HC"
] | eess.AS | cs.HC | Audio and Speech Processing;Human-Computer Interaction | 7,267longtail
|
1205.6206 | BL Lacertae (Lac) objects that are detected at very-high energies (VHE) are
of fundamental importance to study multiple astrophysical processes, including
the physics of jets, the properties of the extragalactic background light and
the strength of the intergalactic magnetic field. Unfortunately, since most
blazars have featureless optical spectra that preclude a redshift
determination, a substantial fraction of these VHE extragalactic sources cannot
be used for cosmological studies. To assess whether molecular lines are a
viable way to establish distances, we have undertaken a pilot program at the
IRAM 30m telescope to search for CO lines in three BL Lac objects with known
redshifts. We report a positive detection of M_H2 ~ 3x10^8 Msun toward 1ES
1959+650, but due to the poor quality of the baseline, this value is affected
by a large systematic uncertainty. For the remaining two sources, W Comae and
RGB J0710+591, we derive 3sigma upper limits at, respectively, M_H2 < 8.0x10^8
Msun and M_H2 < 1.6x10^9 Msun, assuming a line width of 150 km/s and a standard
conversion factor alpha=4 M_sun/(K km/s pc^2). If these low molecular gas
masses are typical for blazars, blind redshift searches in molecular lines are
currently unfeasible. However, deep observations are still a promising way to
obtain precise redshifts for sources whose approximate distances are known via
indirect methods. Our observations further reveal a deficiency of molecular gas
in BL Lac objects compared to quasars, suggesting that the host galaxies of
these two types of active galactic nuclei (AGN) are not drawn from the same
parent population. Future observations are needed to assess whether this
discrepancy is statistically significant, but our pilot program shows how
studies of the interstellar medium in AGN can provide key information to
explore the connection between the active nuclei and the host galaxies.
| [
"astro-ph.CO"
] | astro-ph.CO | Cosmology and Nongalactic Astrophysics | 1,725Cosmology and Nongalactic Astrophysics
|
|
1912.02313 | Small exoplanets of nearby M dwarf stars present the possibility to find and
characterize habitable worlds within the next decade. TRAPPIST-1, an ultracool
M dwarf star, was recently found to have seven Earth-sized planets of
predominantly rocky composition. The planets e, f, and g can have a liquid
water ocean on their surface given appropriate atmospheres of N2 and CO2.
Particularly, climate models have shown that the planets e and f can sustain a
global liquid water ocean, for >=0.2 bar CO2 plus 1 bar N2, or >=2 bars CO2,
respectively. These atmospheres are irradiated by ultraviolet emission from the
star's moderately active chromosphere, and the consequence of this irradiation
is unknown. Here we show that chemical reactions driven by the irradiation can
produce and maintain more than 0.2 bar O2 and 0.05 bar CO if the CO2 is >=0.1
bar. The abundance of O2 and CO can rise to more than 1 bar under certain
boundary conditions. Because of this O2-CO runaway, habitable environments on
the TRAPPIST-1 planets entail an O2- and CO-rich atmosphere with coexisting O3.
The only process that would prevent the runaway is direct recombination of O2
and CO in the ocean, a reaction that is facilitated biologically. Our results
indicate that O2, O3, and CO should be considered together with CO2 as the
primary molecules in the search for atmospheric signatures from temperate and
rocky planets of TRAPPIST-1 and other M dwarf stars.
| [
"astro-ph.EP"
] | astro-ph.EP | Earth and Planetary Astrophysics | 2,351Earth and Planetary Astrophysics
|
|
1309.0936 | Messenger RNA encodes a sequence of amino acids by using codons. For most
amino acids there are multiple synonymous codons that can encode the amino
acid. The translation speed can vary from one codon to another, thus there is
room for changing the ribosome speed while keeping the amino acid sequence and
hence the resulting protein. Recently, it has been noticed that the choice of
the synonymous codon, via the resulting distribution of slow- and
fast-translated codons, affects not only on the average speed of one ribosome
translating the messenger RNA (mRNA) but also might have an effect on nearby
ribosomes by affecting the appearance of "traffic jams" where multiple
ribosomes collide and form queues. To test this "context effect" further, we
here investigate the effect of the sequence of synonymous codons on the
ribosome traffic by using a ribosome traffic model with codon-dependent rates,
estimated from experiments. We compare the ribosome traffic on wild type
sequences and sequences where the synonymous codons were swapped randomly. By
simulating translation of 87 genes, we demonstrate that the wild type
sequences, especially those with a high bias in codon usage, tend to have the
ability to reduce ribosome collisions, hence optimizing the cellular investment
in the translation apparatus. The magnitude of such reduction of the
translation time might have a significant impact on the cellular growth rate
and thereby have importance for the survival of the species.
| [
"q-bio.SC",
"q-bio.GN"
] | q-bio.SC | q-bio.GN | Subcellular Processes;Genomics | 7,267longtail
|
2112.12964 | Recent research in the geometric formulation of quantum theory has implied
that Weyl Geometry can be used to merge quantum theory and general relativity
consistently as classical field theories. In the Weyl Geometric framework, it
seems that both quantum theory and gravity can merge consistently, once quantum
theory is geometrized. The extended differential geometry can modify the
quantum mechanical results into a more general nonlinear framework. Author
shows that, how the extended differential geometry modifies the known quantum
equations and also the modification to the Maxwell's electromagnetic equations.
| [
"gr-qc",
"quant-ph"
] | gr-qc | quant-ph | General Relativity and Quantum Cosmology;Quantum Physics | 2,774General Relativity and Quantum Cosmology;Quantum Physics
|