Results for "Xiaofei Zhao"

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A modulation equations approach for numerically solving the moving soliton and radiation solutions of NLSAug 25 2015Feb 05 2016Based on our previous work for solving the nonlinear Schrodinger equation with multichannel dynamics that is given by a localized standing wave and radiation, in this work we deal with the multichannel solution which consists of a moving soliton and radiation. ... More
A uniformly accurate multiscale time integrator pseudospectral method for the Klein-Gordon equation in the nonrelativistic limit regimeJan 06 2014May 09 2014We propose and analyze a multiscale time integrator Fourier pseudospectral (MTI-FP) method for solving the Klein-Gordon (KG) equation with a dimensionless parameter $0<\varepsilon\leq1$ which is inversely proportional to the speed of light. In the nonrelativistic ... More
Broad band invisibility cloak made of normal dielectric multilayerSep 29 2011We present the design, fabrication and performance test of a quasi three-dimensional carpet cloak made of normal dielectric in the microwave regime. Taking advantage of a simple linear coordinate transformation we design a carpet cloak with homogeneous ... More
A uniformly and optimally accurate method for the Klein-Gordon-Zakharov system in simultaneous high-plasma-frequency and subsonic limit regimeApr 09 2019We present a uniformly and optimally accurate numerical method for solving the Klein-Gordon-Zakharov (KGZ) system with two dimensionless parameters $0<\epsilon\le1$ and $0<\gamma\le 1$, which are inversely proportional to the plasma frequency and the ... More
Symmetric high order Gautschi-type exponential wave integrators pseudospectral method for the nonlinear Klein-Gordon equation in the nonrelativistic limit regimeNov 04 2016A group of high order Gautschi-type exponential wave integrators (EWIs) Fourier pseudospectral method are proposed and analyzed for solving the nonlinear Klein-Gordon equation (KGE) in the nonrelativistic limit regime, where a parameter $0<\varepsilon\ll1$ ... More
Modulation equations approach for solving vortex and radiation in nonlinear Schrodinger equationMay 03 2016We apply the modulation theory to study the vortex and radiation solution in the two-dimensional nonlinear Schr\"{o}dinger equation. The full modulation equations which describe the dynamics of the vortex and radiation separately are derived. A general ... More
On multichannel solutions of nonlinear Schrödinger equations: algorithm, analysis and numerical explorationsApr 04 2014Feb 17 2015We apply the method of modulation equations to numerically solve the NLS with multichannel dynamics, given by a trapped localized state and radiation. This approach employs the modulation theory of Soffer-Weinstein, which gives a system of ODE's coupled ... More
A uniformly accurate (UA) multiscale time integrator Fourier pseoduspectral method for the Klein-Gordon-Schrodinger equations in the nonrelativistic limit regimeMay 01 2015A multiscale time integrator Fourier pseudospectral (MTI-FP) method is proposed and analyzed for solving the Klein-Gordon-Schr\"{o}dinger (KGS) equations in the nonrelativistic limit regime with a dimensionless parameter $0<\varepsilon\le1$ which is inversely ... More
Scalar-field theory of dark matterApr 05 2013Apr 29 2014We develop a theory of dark matter based on a previously proposed picture, in which a complex vacuum scalar field makes the universe a superfluid, with the energy density of the superfluid giving rise to dark energy, and variations from vacuum density ... More
Low-regularity integrators for nonlinear Dirac equationsJun 22 2019In this work, we consider the numerical integration of the nonlinear Dirac equation and the Dirac-Poisson system (NDEs) under rough initial data. We propose a ultra low-regularity integrator (ULI) for solving the NDEs which enables optimal first-order ... More
Uniformly accurate numerical schemes for the nonlinear Dirac equation in the nonrelativistic limit regimeMay 09 2016We apply the two-scale formulation approach to propose uniformly accurate (UA) schemes for solving the nonlinear Dirac equation in the nonrelativistic limit regime. The nonlinear Dirac equation involves two small scales $\varepsilon$ and $\varepsilon^2$ ... More
Uniformly accurate numerical schemes for the nonlinear Dirac equation in the nonrelativistic limit regimeMay 09 2016Dec 17 2016We apply the two-scale formulation approach to propose uniformly accurate (UA) schemes for solving the nonlinear Dirac equation in the nonrelativistic limit regime. The nonlinear Dirac equation involves two small scales $\varepsilon$ and $\varepsilon^2$ ... More
Uniformly accurate multiscale time integrators for highly oscillatory second order differential equationsDec 20 2012Feb 14 2014In this paper, two multiscale time integrators (MTIs), motivated from two types of multiscale decomposition by either frequency or frequency and amplitude, are proposed and analyzed for solving highly oscillatory second order differential equations with ... More
Deep Reinforcement Learning for Sponsored Search Real-time BiddingMar 01 2018Bidding optimization is one of the most critical problems in online advertising. Sponsored search (SS) auction, due to the randomness of user query behavior and platform nature, usually adopts keyword-level bidding strategies. In contrast, the display ... More
Uniformly accurate methods for three dimensional Vlasov equations under strong magnetic field with varying directionJul 10 2019In this paper, we consider the three dimensional Vlasov equation with an inhomogeneous, varying direction, strong magnetic field. Whenever the magnetic field has constant intensity, the oscillations generated by the stiff term are periodic. The homogenized ... More
Open-Ended Long-Form Video Question Answering via Hierarchical Convolutional Self-Attention NetworksJun 28 2019Open-ended video question answering aims to automatically generate the natural-language answer from referenced video contents according to the given question. Currently, most existing approaches focus on short-form video question answering with multi-modal ... More
Keyword-based Query Comprehending via Multiple Optimized-Demand AugmentationNov 01 2017In this paper, we consider the problem of machine reading task when the questions are in the form of keywords, rather than natural language. In recent years, researchers have achieved significant success on machine reading comprehension tasks, such as ... More
Dialogue Act Recognition via CRF-Attentive Structured NetworkNov 15 2017Dialogue Act Recognition (DAR) is a challenging problem in dialogue interpretation, which aims to attach semantic labels to utterances and characterize the speaker's intention. Currently, many existing approaches formulate the DAR problem ranging from ... More
Infrared carpet cloak designed with uniform silicon grating structureOct 22 2009Through a particularly chosen coordinate transformation, we propose an optical carpet cloak that only requires homogeneous anisotropic dielectric material. The proposed cloak could be easily imitated and realized by alternative layers of isotropic dielectrics. ... More
Uniformly accurate methods for Vlasov equations with non-homogeneous strong magnetic fieldFeb 08 2018In this paper, we consider the numerical solution of highly-oscillatory Vlasov and Vlasov-Poisson equations with non-homogeneous magnetic field. Designed in the spirit of recent uniformly accurate methods, our schemes remain insensitive to the stiffness ... More
On Strategyproof Conference Peer ReviewJun 16 2018Nov 14 2018We consider peer review in a conference setting where there is typically an overlap between the set of reviewers and the set of authors. This overlap can incentivize strategic reviews to influence the final ranking of one's own papers. In this work, we ... More
Simple Model of Sickle HemogloblinOct 24 2005A microscopic model is proposed for the interactions between sickle hemoglobin molecules based on information from the protein data bank. A Monte Carlo simulation of a simplified two patch model is carried out, with the goal of understanding fiber formation. ... More
Ion specific effects on phase transitions in protein solutionsJan 12 2009A recent Monte Carlo simulation determined the potential of mean force between two lysozyme molecules in various aqueous solutions [M. Lund et al. Phys. Rev. Lett. 100, 258105 (2008)]. The study involved a combination of explicit solvent and continuum ... More
Electromagnetic beam modulating through transformation optical structuresJun 05 2008Jun 06 2008The transformation media concept based on the form-invariant Maxwell's equations under coordinate transformations has opened up new possibilities to manipulate the electromagnetic fields. In this paper we report on applying the finite-embedded coordinate ... More
Patch-based adaptive weighting with segmentation and scale (PAWSS) for visual trackingAug 03 2017Tracking-by-detection algorithms are widely used for visual tracking, where the problem is treated as a classification task where an object model is updated over time using online learning techniques. In challenging conditions where an object undergoes ... More
Asset Pricing with General Transaction Costs: Theory and NumericsMay 13 2019Jun 07 2019We study risk-sharing equilibria with general convex costs on the agents' trading rates. For an infinite-horizon model with linear state dynamics and exogenous volatilities, the equilibrium returns mean-revert around their frictionless counterparts -- ... More
Electronic properties of a $π$-conjugated Cairo pentagonal lattice: Direct band gap, ultrahigh carrier mobility and slant Dirac conesAug 02 2018Two-dimensional (2D) lattices composed exclusively of pentagons represent an exceptional structure of materials correlated to the famous pentagonal tiling problem in mathematics, but their $\pi$-conjugation and the related electronic properties have never ... More
Estimating the sample mean and standard deviation from commonly reported quantiles in meta-analysisMar 25 2019Researchers increasingly use meta-analysis to synthesize the results of several studies in order to estimate a common effect. When the outcome variable is continuous, standard meta-analytic approaches assume that the primary studies report the sample ... More
In-Edge AI: Intelligentizing Mobile Edge Computing, Caching and Communication by Federated LearningSep 19 2018Recently, along with the rapid development of mobile communication technology, edge computing theory and techniques have been attracting more and more attentions from global researchers and engineers, which can significantly bridge the capacity of cloud ... More
Smarnet: Teaching Machines to Read and Comprehend Like HumanOct 08 2017Machine Comprehension (MC) is a challenging task in Natural Language Processing field, which aims to guide the machine to comprehend a passage and answer the given question. Many existing approaches on MC task are suffering the inefficiency in some bottlenecks, ... More
DeepCruiser: Automated Guided Testing for Stateful Deep Learning SystemsDec 13 2018Deep learning (DL) defines a data-driven programming paradigm that automatically composes the system decision logic from the training data. In company with the data explosion and hardware acceleration during the past decade, DL achieves tremendous success ... More
MEMEN: Multi-layer Embedding with Memory Networks for Machine ComprehensionJul 28 2017Machine comprehension(MC) style question answering is a representative problem in natural language processing. Previous methods rarely spend time on the improvement of encoding layer, especially the embedding of syntactic information and name entity of ... More
ATRank: An Attention-Based User Behavior Modeling Framework for RecommendationNov 17 2017Nov 27 2017A user can be represented as what he/she does along the history. A common way to deal with the user modeling problem is to manually extract all kinds of aggregated features over the heterogeneous behaviors, which may fail to fully represent the data itself ... More
One-sample aggregate data meta-analysis of mediansSep 09 2017Dec 15 2017An aggregate data meta-analysis is a statistical method that pools the summary statistics of several selected studies to estimate the outcome of interest. When considering a continuous outcome, typically each study must report the same measure of the ... More
Characterization of Generalized Jordan Higher Derivations on Triangular ringsDec 31 2010Let $\mathcal A$ and $\mathcal B$ be unital rings and $\mathcal M$ be a $(\mathcal A, \mathcal B)$-bimodule, which is faithful as a left $\mathcal A$-module and also as a right $\mathcal B$-module. Let ${\mathcal U}={\rm Tri}(\mathcal A, \mathcal M, \mathcal ... More
Improved Algorithms for Adaptive Compressed SensingApr 25 2018In the problem of adaptive compressed sensing, one wants to estimate an approximately $k$-sparse vector $x\in\mathbb{R}^n$ from $m$ linear measurements $A_1 x, A_2 x,\ldots, A_m x$, where $A_i$ can be chosen based on the outcomes $A_1 x,\ldots, A_{i-1} ... More
Audio-noise Power Spectral Density Estimation Using Long Short-term MemoryApr 10 2019We propose a method using a long short-term memory (LSTM) network to estimate the noise power spectral density (PSD) of single-channel audio signals represented in the short time Fourier transform (STFT) domain. An LSTM network common to all frequency ... More
An Orchestrated Empirical Study on Deep Learning Frameworks and PlatformsNov 13 2018Deep learning (DL) has recently achieved tremendous success in a variety of cutting-edge applications, e.g., image recognition, speech and natural language processing, and autonomous driving. Besides the available big data and hardware evolution, DL frameworks ... More
Nuclear Effects on Heavy Boson Production at RHIC and LHCFeb 04 2002We predict W and Z transverse momentum distributions from proton-proton and nuclear collisions at RHIC and LHC. A resummation formalism with power corrections to the renormalization group equations is used. The dependence of the resummed QCD results on ... More
Construction of weakly neutral inclusions of general shape by imperfect interfacesMay 06 2018Upon insertion of an inclusion into a medium with the uniform field, if the field is not perturbed at all outside the inclusion, then it is called a neutral inclusion. It is called a weakly neutral inclusion if the field is perturbed weakly. The inclusions ... More
Metamorphic Relation Based Adversarial Attacks on Differentiable Neural ComputerSep 07 2018Deep neural networks (DNN), while becoming the driving force of many novel technology and achieving tremendous success in many cutting-edge applications, are still vulnerable to adversarial attacks. Differentiable neural computer (DNC) is a novel computing ... More
Non-Abelian Kubo Formula and the Multiple Time-Scale MethodMay 17 1996The non-Abelian Kubo formula is derived from the kinetic theory. That expression is compared with the one obtained using the eikonal for a Chern-Simons theory. The multiple time-scale method is used to solve the non-Abelian Kubo formula, and the damping ... More
QCD prediction for heavy boson transverse momentum distributionsDec 05 2000We investigate the predictive power of Collins, Soper, and Sterman's $b$-space QCD resummation formalism for transverse momentum ($Q_T$) distributions of heavy boson production in hadronic collisions. We show that the predictive power of the resummation ... More
ABtree: An Algorithm for Subgroup-Based Treatment AssignmentMay 13 2016Given two possible treatments, there may exist subgroups who benefit greater from one treatment than the other. This problem is relevant to the field of marketing, where treatments may correspond to different ways of selling a product. It is similarly ... More
Fidelity of states in infinite dimensional quantum systemsJul 02 2011In this paper we discuss the fidelity of states in infinite dimensional systems, give an elementary proof of the infinite dimensional version of Uhlmann's theorem, and then, apply it to generalize several properties of the fidelity from finite dimensional ... More
DeepHunter: Hunting Deep Neural Network Defects via Coverage-Guided FuzzingSep 04 2018Nov 16 2018In company with the data explosion over the past decade, deep neural network (DNN) based software has experienced unprecedented leap and is becoming the key driving force of many novel industrial applications, including many safety-critical scenarios ... More
Role of nonperturbative input in QCD resummed heavy boson $Q_T$ distributionMay 12 2002We show that role of nonperturbative input in the $b$-space QCD resummation formalism for heavy boson transverse momentum ($Q_T$) distribution strongly depends on collision energy $\sqrt{S}$. At collider energies, the larger $\sqrt{S}$ is, the weaker ... More
Echo: An Edge-Centric Code Offloading System with Quality of Service GuaranteeJun 04 2018Code offloading is promising to accelerate mobile applications and save energy of mobile devices by shifting some computation to cloud. However, existing code offloading systems suffer from a long communication delay between mobile devices and cloud. ... More
Linear maps preserving separability of pure statesOct 08 2012Apr 03 2013Linear maps preserving pure states of a quantum system of any dimension are characterized. This is then used to establish a structure theorem for linear maps that preserve separable pure states in multipartite systems. As an application, a characterization ... More
Additive Lie ($ξ$-Lie) Derivations and Generalized Lie ($ξ$-Lie) Derivations on Prime AlgebrasApr 10 2010The additive (generalized) $\xi$-Lie derivations on prime algebras are characterized. It is shown, under some suitable assumption, that an additive map $L$ is an additive (generalized) Lie derivation if and only if it is the sum of an additive (generalized) ... More
On the local times of stationary processes with conditional local limit theoremsApr 14 2017We investigate the connection between conditional local limit theorems and the local time of integer-valued stationary processes. We show that a conditional local limit theorem (at 0) implies the convergence of local times to Mittag-Leffler distributions, ... More
Automated pick-up of suturing needles for robotic surgical assistanceApr 09 2018Robot-assisted laparoscopic prostatectomy (RALP) is a treatment for prostate cancer that involves complete or nerve sparing removal prostate tissue that contains cancer. After removal the bladder neck is successively sutured directly with the urethra. ... More
A cascaded multiple-speaker localization and tracking systemDec 11 2018This paper presents an online multiple-speaker localization and tracking method, as the INRIA-Perception contribution to the LOCATA Challenge 2018. First, the recursive least-square method is used to adaptively estimate the direct-path relative transfer ... More
Bounds on the size of an inclusion using the translation method for two-dimensional complex conductivityOct 09 2013The size estimation problem in electrical impedance tomography is considered when the conductivity is a complex number and the body is two-dimensional. Upper and lower bounds on the volume fraction of the unknown inclusion embedded in the body are derived ... More
The charged-hadron/pion ratio at the Relativistic Heavy Ion ColliderJun 24 2003Jul 20 2004The hadron/pion ratio is calculated in 200 GeV AuAu collisions at midrapidity, applying pQCD and non-universal transverse-momentum broadening. Arguments are presented for such non-universality, and the idea is implemented in a model, which explains the ... More
$Z^0$ and W transverse momentum spectra at the LHCDec 02 2002We discuss the transverse momentum distribution of $Z^0$ and $W^\pm$ gauge bosons at the LHC with $\sqrt s=14$ TeV for pp collisions and with $\sqrt s=5.5$ TeV for Pb+Pb collisions. Effects of power corrections and shadowing are also studied.
Positive finite rank elementary operators and characterizing entanglement of statesAug 22 2010Sep 01 2010In this paper, a class of indecomposable positive finite rank elementary operators of order $(n,n)$ are constructed. This allows us to give a simple necessary and sufficient criterion for separability of pure states in bipartite systems of any dimension ... More
Constructing entanglement witnesses for infinite-dimensional systemsMay 30 2010Jun 09 2010It is shown that, every entangled state in an infinite-dimensional composite system has a simple entanglement witness of the form $\alpha I+T$ with $\alpha$ a nonnegative number and $T$ a finite rank self-adjoint operator. We also provide two methods ... More
Strong skew commutativity preserving maps on von Neumann algebrasApr 09 2012Let ${\mathcal M}$ be a von Neumann algebra without central summands of type $I_1$. Assume that $\Phi:{\mathcal M}\rightarrow {\mathcal M}$ is a surjective map. It is shown that $\Phi$ is strong skew commutativity preserving (that is, satisfies $\Phi(A)\Phi(B)-\Phi(B)\Phi(A)^*=AB-BA^*$ ... More
Detecting entanglement of states by entries of their density matricesOct 11 2010Oct 22 2010For any bipartite systems, a universal entanglement witness of rank-4 for pure states is obtained and a class of finite rank entanglement witnesses is constructed. In addition, a method of detecting entanglement of a state only by entries of its density ... More
Surface Delta Interaction and g factorsSep 20 2015Mar 07 2016Using an attractive surface delta interaction we obtain wave functions for 2 neutrons (or neutron holes) in the model space of 2 orbits (l=4, j=7/2) and (l=2, j=5/2). If we take the single particle energies to be degenerate we find that the g factors ... More
Scaling Up Sparse Support Vector Machines by Simultaneous Feature and Sample ReductionJul 24 2016Jun 23 2017Sparse support vector machine (SVM) is a popular classification technique that can simultaneously learn a small set of the most interpretable features and identify the support vectors. It has achieved great successes in many real-world applications. However, ... More
Occupation times of discrete-time fractional Brownian motionFeb 01 2017We prove a conditional local limit theorem for discrete-time fractional Brownian motions (dfBm) with Hurst parameter 3/4<H<1. Using results from infinite ergodic theory it is then shown that the properly scaled occupation time of dfBm converges to a Mittag-Leffler ... More
Z Production as a Test of Nuclear Effects at the LHCMay 15 2002We predict the Z transverse momentum distribution from proton-proton and nuclear collisions at the LHC. After demonstrating that higher-twist nuclear effects are very small, we propose $Z^0$ production as a precision test for leading-twist pQCD in the ... More
Role of the nonperturbative input in QCD resummed Drell-Yan $Q_T$-distributionsDec 27 2000Feb 20 2001We analyze the role of the nonperturbative input in the Collins, Soper, and Sterman (CSS)'s $b$-space QCD resummation formalism for Drell-Yan transverse momentum ($Q_T$) distributions, and investigate the predictive power of the CSS formalism. We find ... More
Virtual photon fragmentation functionsDec 31 2000Feb 11 2001We introduce operator definitions for virtual photon fragmentation functions, which are needed for reliable calculations of Drell-Yan transverse momentum ($Q_T$) distributions when $Q_T$ is much larger than the invariant mass $Q$. We derive the evolution ... More
Strong nuclear enhancement in intermediate mass Drell-Yan productionSep 24 2001We calculate nuclear effect in Drell-Yan massive lepton-pair production in terms of parton multiple scattering in Quantum Chromodynamics (QCD). We present the nuclear modification to inclusive Drell-Yan cross section $d\sigma/dQ^2$ in terms of multiparton ... More
Order-book modelling and market making strategiesJun 13 2018Market making is one of the most important aspects of algorithmic trading, and it has been studied quite extensively from a theoretical point of view. The practical implementation of so-called "optimal strategies" however suffers from the failure of most ... More
Inter-rater Agreement on Sentence FormalitySep 01 2011Apr 20 2014Formality is one of the most important dimensions of writing style variation. In this study we conducted an inter-rater reliability experiment for assessing sentence formality on a five-point Likert scale, and obtained good agreement results as well as ... More
Characterization of Lie Derivations on von Neumann AlgebrasMay 05 2012Let ${\mathcal M}$ be a von Neumann algebra without central summands of type $I_1$ and $\xi\in{\mathbb C}$ a scalar. It is shown that an additive map $L$ on $\mathcal M$ satisfies $L(AB-\xi BA)=L(A)B-\xi BL(A)+L(B)A-\xi AL(B)$ whenever $A,B\in{\mathcal ... More
A characterization of optimal entanglement witnessesSep 11 2011In this paper, we present a characterization of optimal entanglement witnesses in terms of positive maps and then provide a general method of checking optimality of entanglement witnesses. Applying it, we obtain new indecomposable optimal witnesses which ... More
Optimality of a class of entanglement witnesses for $3\otimes 3$ systemsJan 31 2013Let $\Phi_{t,\pi}: M_3({\mathbb C}) \rightarrow M_3({\mathbb C})$ be a linear map defined by $\Phi_{t,\pi}(A)=(3-t)\sum_{i=1}^3E_{ii}AE_{ii}+t\sum_{i=1}^3E_{i,\pi(i)}AE_{i,\pi(i)}^\dag-A$, where $0\leq t\leq 3$ and $\pi$ is a permutation of $(1,2,3)$. ... More
Description of Brownian motion including both kinetic and hydrodynamic effectsDec 02 2017Feb 12 2018It is known that a full description of Brownian motion in the entire course of time should incorporate both kinetic and hydrodynamic effects, but a formula accounts for both effects has been established only in three dimension and only for the limiting ... More
fc: A Package for Generalized Function Composition Using Standard EvaluationJun 28 2018In this article, we present a new R package fc that provides a streamlined, standard evaluation-based approach to function composition. Using fc, a sequence of functions can be composed together such that returned objects from composed functions are used ... More
Adaptation and Re-Identification Network: An Unsupervised Deep Transfer Learning Approach to Person Re-IdentificationApr 25 2018Person re-identification (Re-ID) aims at recognizing the same person from images taken across different cameras. To address this task, one typically requires a large amount labeled data for training an effective Re-ID model, which might not be practical ... More
The hard-disk fluid revisitedNov 02 2015May 21 2016The hard-disk model plays a role of touchstone for testing and developing the transport theory. By large scale molecular dynamics simulations of this model, three important autocorrelation functions, and as a result the corresponding transport coefficients, ... More
Bayesian Change Point Analysis of Linear Models on GraphsSep 02 2015Consider observations $y_1,\dots,y_n$ on nodes of a connected graph, where the $y_i$ independently come from $N(\theta_i, \sigma^2)$ distributions and an unknown partition divides the $n$ observations into blocks. One well-studied class of change point ... More
Interpolation maps and congruence domains for wavelet setsOct 29 2007It is proven that if an interpolation map between two wavelet sets preserves the union of the sets, then the pair must be an interpolation pair. We also construct an example of a pair of wavelet sets for which the congruence domains of the associated ... More
Water Vapor: An Extraordinary Terahertz Wave Source under Optical ExcitationFeb 12 2009In modern terahertz (THz) sensing and imaging spectroscopy, water is considered a nemesis to be avoided due to strong absorption in the THz frequency range. Here we report the first experimental demonstration and theoretical implications of using femtosecond ... More
Existence and Stability of Coexistence States for a Nonlocal Evolution SystemMay 20 2011Mar 05 2012In this paper, we study a nonlocal evolution system. We apply abstract results from the bifurcation theory to obtain the existence of coexistence states. Their stability are investigated as well.
A Clustering Based Approach for Realistic and Efficient Data-Driven Crowd SimulationJun 15 2015Oct 29 2015In this paper, we present a data-driven approach to generate realistic steering behaviors for virtual crowds in crowd simulation. We take advantage of both rule-based models and data-driven models by applying the interaction patterns discovered from crowd ... More
Extremal regular graphs: independent sets and graph homomorphismsOct 28 2016This survey concerns regular graphs that are extremal with respect to the number of independent sets, and more generally, graph homomorphisms. The main motivating problem is the following: in the family of $d$-regular graphs, which graph $G$ maximize/minimize ... More
A Spectral Analysis of Subspace Enchanced PreconditionersApr 07 2013It is well-known that the convergence of Krylov subspace methods to solve linear system depends on the spectrum of the coefficient matrix, moreover, it is widely accepted that for both symmetric and unsymmetric systems Krylov subspace methods will converge ... More
A Study on Perturbation Analysis of Spectral PreconditionersOct 10 2011Dec 10 2011It is well-known that the convergence of Krylov subspace methods to solve linear system depends on the spectrum of the coefficient matrix, moreover, it is widely accepted that for both symmetric and unsymmetric systems Krylov subspace methods will converge ... More
Remarks on PBW bases of Ringel-Hall algebras of cyclic quiversAug 22 2016In this paper, we give a recursive formula for the interesting PBW basis $E_{A}$ of composition subalgebras of Ringel-Hall algebras $\fkH_\vartri(n)$ of cyclic quivers after \cite{DengDuXiao2007generic}, and another construction of canonical bases of ... More
Ballistic Motion in One-Dimensional Quasi-Periodic Discrete Schrödinger EquationJul 31 2015Feb 10 2016For the solution $q(t)=(q_n(t))_{n\in\mathbb Z}$ to one-dimensional discrete Schr\"odinger equation $${\rm i}\dot{q}_n=-(q_{n+1}+q_{n-1})+ V(\theta+n\omega) q_n, \quad n\in\mathbb Z,$$ with $\omega\in\mathbb R^d$ Diophantine, and $V$ a small real-analytic ... More
Note on a class of anisotropic Einstein metricsJun 24 2011A class of anisotropic Einstein metrics is presented. These metrics are axial symmetric and contains an anisotropy parameter $\alpha$, which is identified as the amplitude of the proper acceleration of the origin, thus explaining the ellipsoid shape of ... More
Duality for relative logarithmic de Rham-Witt sheaves on semistable schemes over $\mathbb{F}_q[[t]]$Nov 26 2016We study duality theorems for the relative logarithmic de Rham-Witt sheaves on semi-stable schemes $X$ over a local ring $\mathbb{F}_q[[t]]$, where $\mathbb{F}_q$ is a finite field. As an application, we obtain a new filtration on the maximal abelian ... More
Are Children Well-Supported by Their Parents Concerning Online Privacy Risks, and Who Supports the Parents?Sep 28 2018Tablet computers are becoming ubiquitously available at home or school for young children to complement education or entertainment. However, parents of children aged 6-11 often believe that children are too young to face or comprehend online privacy issues, ... More
Numerical Implementation of Gauge-Fixed Fourier AccelerationDec 14 2018In hybrid Monte Carlo evolution, by imposing a physical gauge condition, simple Fourier acceleration can be used to generate conjugate momenta and potentially reduce critical slowing down. This modified gauge evolution algorithm does not change the gauge-independent ... More
Irregular Channel Polarization and Its Applications to Static Adversarial Wiretap ChannelDec 01 2018The problem of achieving the secrecy capacity of static adversarial wiretap channel with discrete memoryless channels is studied in this paper. To construct the explicit secure coding scheme, an irregular channel polarization operation is proposed which ... More
Deep Multimodal Learning: An Effective Method for Video ClassificationNov 30 2018Videos have become ubiquitous on the Internet. And video analysis can provide lots of information for detecting and recognizing objects as well as help people understand human actions and interactions with the real world. However, facing data as huge ... More
Quantum Statistical InferenceDec 12 2018In this thesis, I present several results on quantum statistical inference in the following two directions. Firstly, I demonstrate that quantum algorithms can be applied to enhance the computing and training of Gaussian processes (GPs), a powerful model ... More
Representations of Lie superalgebras in prime characteristic IIIOct 12 2009For a restricted Lie superalgebra g over an algebraically closed field of characteristic p > 2, we generalize the deformation method of Premet and Skryabin to obtain results on the p-power and 2-power divisibility of dimensions of g-modules. In particular, ... More
Network Analysis of Urban Traffic with Big Bus DataJun 21 2016Urban traffic analysis is crucial for traffic forecasting systems, urban planning and, more recently, various mobile and network applications. In this paper, we analyse urban traffic with network and statistical methods. Our analysis is based on one big ... More
Multiple Harmonic Series I: Generalizations of Wolstenholme's TheoremJan 22 2003Feb 15 2006In this paper we will study the p-divisibility of partial sums of multiple zeta value series. In particular we provide some generalizations of the classical Wolstenholme's Theorem.
Maximally Frobenius-destabilized vector bundles over smooth algebraic curvesAug 21 2014Aug 17 2017Vector bundles in positive characteristics have a tendency to be destabilized after pulling back by the Frobenius morphism. In this paper, we closely examine vector bundles over curves that are, in an appropriate sense, maximally destabilized by the Frobenius ... More
Perturbations of the Yang-Mills field in the universeJul 30 2005Jul 15 2009It has been suggested that the Yang-Mills (YM) field can be a kind of candidate for the inflationary field at high energy scales or the dark energy at very low energy scales, which can naturally give the equation of state $-1<\omega<0$ or $\omega<-1$. ... More
A Family of Invariants of Rooted ForestsNov 05 2002May 24 2003Let $A$ be a commutative $k$-algebra over a field of $k$ and $\Xi$ a linear operator defined on $A$. We define a family of $A$-valued invariants $\Psi$ for finite rooted forests by a recurrent algorithm using the operator $\Xi$ and show that the invariant ... More
Constraint on the early Universe by relic gravitational waves: From pulsar timing observationsMar 21 2011May 06 2011Recent pulsar timing observations by the Parkers Pulsar Timing Array and European Pulsar Timing Array teams obtained the constraint on the relic gravitational waves at the frequency $f_*=1/{\rm yr}$, which provides the opportunity to constrain $H_*$, ... More