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Results for "Xu Liu"

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Budget-aware Online Task Assignment in Spatial CrowdsourcingJul 26 2018The prevalence of mobile internet techniques stimulates the emergence of various spatial crowdsourcing applications. Certain of the applications serve for requesters, budget providers, who submit a batch of tasks and a fixed budget to platform with the ... More
A Monte Carlo Study on the Identification of Quark-gluon Fusion Product in QCD-instanton Induced Processes in Deep-inelastic ScatteringOct 18 2006Different methods to reconstruct the quark-gluon fusion product and current jet are tried in deep-inelastic e-p scattering events with instanton as background generated by QCDINS Monte Carlo code. A comparison of these methods are performed and a good ... More
Some Asymptotic Results of Gaussian Random Fields with Varying Mean Functions and the Associated ProcessesApr 10 2011Dec 02 2011In this paper, we derive tail approximations of integrals of exponential functions of Gaussian random fields with varying mean functions and approximations of the associated point processes. This study is motivated naturally by multiple applications such ... More
Liquid refractive index sensing independent of opacity using an optofluidic sensor based on diffractionOct 03 2014Oct 15 2014We have implemented a multi-functional optofluidic sensor that can monitor changes in the refractive index and pressure of biofluid simultaneously and can detect free-solution molecular interaction in-situ. In this paper, we demonstrate two major improvements ... More
Monolithic Integrations of Slanted Silicon Nanostructures on 3D Microstructures and Their Application to Surface Enhanced Raman SpectroscopyFeb 07 2014We demonstrated fabrication of black silicon with slanted nanocone array on both planar and 3D micro and meso scale structures produced by a high-throughput lithography-free oblique-angle plasma etching process. Nanocones with gradual change in height ... More
Lithography-free sub-100nm nanocone array antireflection layer for low-cost silicon solar cellFeb 07 2014High density and uniformity sub-100nm surface oxidized silicon nanocone forest structure is created and integrated onto the existing texturization microstructures on photovoltaic device surface by a one-step high throughput plasma enhanced texturization ... More
Quick Detection of Contaminants Leaching from Polypropylene Centrifuge Tube with Surface Enhanced Raman Spectroscopy and Ultra Violet Absorption SpectroscopyFeb 07 2014Anomalous surface enhanced Raman scattering (SERS) peaks are identified for liquid sample stored in polypropylene centrifuge tubes (PP tube) for months. We observed the unexpected Raman peaks during experiments for Thiamine Hydrochloride aqueous solution ... More
A Paradigm for Modeling and Computation of Gas DynamicsAug 01 2016In the continuum flow regime, the Navier-Stokes equations are usually used for the description of gas dynamics. On the other hand, the Boltzmann equation is applied for the rarefied gas dynamics. Both equations are constructed from modeling flow physics ... More
A Unified Gas Kinetic Scheme for Multi-scale and Multi-component Plasma TransportSep 17 2016Feb 22 2017A unified gas kinetic scheme (UGKS) for multi-scale and multi-component plasma transport is constructed. The current scheme is a direct modeling method, where the time evolution solutions from the Vlasov-BGK equations of electron and ion and the Maxwell ... More
Geographic Trough Filling for Internet DatacentersAug 28 2011To reduce datacenter energy consumption and cost, current practice has considered demand-proportional resource provisioning schemes, where servers are turned on/off according to the load of requests. Most existing work considers instantaneous (Internet) ... More
Scaling Dark Energy in a Five-Dimensional Bouncing Cosmological ModelJul 11 2005Dec 31 2005We consider a 5-dimensional Ricci flat bouncing cosmological model in which the 4-dimensional induced matter contains two components at late times - the cold dark matter (CDM)+baryons and dark energy. We find that the arbitrary function $f(z)$ contained ... More
Critical phenomena of static charged AdS black holes in conformal gravityMay 29 2014Aug 18 2014The extended thermodynamics of static charged AdS black holes in conformal gravity is analyzed. The $P-V$ criticality of these black holes has some unusual features. There exists a single critical point with critical temperature $T_c$ and critical pressure ... More
A minimax principle to the injectivity of the Jacobian conjectureFeb 10 2019The main result of this paper is to prove some type of Real Jacobian Conjecture. It is proved by the Minimax Principle and asserts if the eigenvalues of $F'(x)$ are bounded from zero and all the eigenvalues of $F'(x)+F'(x)^T$ are strictly same sign, where ... More
Galois Hulls of Linear Codes over Finite FieldsSep 21 2018The $\ell$-Galois hull $h_{\ell}(C)$ of an $[n,k]$ linear code $C$ over a finite field $\mathbb{F}_q$ is the intersection of $C$ and $C^{{\bot}_{\ell}}$, where $C^{\bot_{\ell}}$ denotes the $\ell$-Galois dual of $C$ which introduced by Fan and Zhang (2017). ... More
Rigidity of spacelike translating solitons in pseudo-Euclidean spaceApr 18 2018In this paper, we investigate the parametric version and non-parametric version of rigidity theorem of spacelike translating solitons in pseudo-Euclidean space $\mathbb{R}^{m+n}_{n}$. Firstly, we classify $m$-dimensional complete spacelike translating ... More
Elastomeric 2D Grating and Hemispherical Optofluidic Chamber for Multifunctional Fluidic SensingFeb 07 2014We present an optofluidic sensor based on an elastomeric two-dimensional (2D) grating integrated inside a hemispherical fluid chamber. Laser beam is diffracted before (reflection) and after (transmission) going through the grating and liquid in the dome ... More
Function Based Nonlinear Least Squares and Application to Jelinski--Moranda Software Reliability ModelAug 25 2011A function based nonlinear least squares estimation (FNLSE) method is proposed and investigated in parameter estimation of Jelinski-Moranda software reliability model. FNLSE extends the potential fitting functions of traditional least squares estimation ... More
The critical order of certain Hecke L-functions of imaginary quadratic fieldsOct 21 2002Let $-D < -4$ denote a fundamental discriminant which is either odd or divisible by 8, so that the canonical Hecke character of $\Bbb Q(\sqrt{-D})$ exists. Let $d$ be a fundamental discriminant prime to $D$. Let $2k-1$ be an odd natural integer prime ... More
A Unified Gas Kinetic Scheme for Multi-scale Plasma TransportSep 17 2016A unified gas kinetic scheme (UGKS) for multi-scale and multi-component plasma transport is constructed. The current scheme is a direct modeling method, where the time evolution solutions from the Vlasov-BGK equations for both electron and ion, and the ... More
A hybrid molecular dynamics/atomic-scale finite element method for quasi-static atomistic simulations at finite temperatureSep 21 2013In this paper, a hybrid quasi-static atomistic simulation method at finite temperature is developed, which combines the advantages of MD for thermal equilibrium and atomic-scale finite element method (AFEM) for efficient equilibration. Some temperature ... More
Charged black hole with a scalar hair in (2+1) dimensionsMay 23 2013Jun 01 2013We obtain and analyze an exact solution to Einstein-Maxwell-scalar theory in $(2+1)$ dimensions, in which the scalar field couples to gravity in a non-minimal way, and it also couples to itself with the self-interacting potential solely determined by ... More
Soundness and completeness of the cirquent calculus system CL6 for computability logicJun 12 2011Computability logic is a formal theory of computability. The earlier article "Introduction to cirquent calculus and abstract resource semantics" by Japaridze proved soundness and completeness for the basic fragment CL5 of computability logic. The present ... More
Computing top intersections in the tautological ring of $M_g$Jan 25 2010We derive effective recursion formulae of top intersections in the tautological ring $R^*(M_g)$ of the moduli space of curves of genus $g\geq 2$. As an application, we prove a convolution-type tautological relation in $R^{g-2}(M_g)$.
Very strong approximation for certain algebraic varietiesMay 08 2014Sep 18 2014Let F be a global field. In this work, we show that the Brauer-Manin condition on adelic points for subvarieties of a torus T over F cuts out exactly the rational points, if either F is a function field or, if F is the field of rational numbers and T ... More
Extended phase space thermodynamics for third order Lovelock black holes in diverse dimensionsMay 16 2014May 22 2014Treating the cosmological constant as thermodynamic pressure and its conjugate as thermodynamic volume, we investigate the critical behavior of the third order Lovelock black holes in diverse dimensions. For black hole horizons with different normalized ... More
Finite Codimensional Controllability for Evolution EquationsDec 17 2016Motivated by infinite-dimensional optimal control problems with endpoint state constraints, in this Note, we introduce the notion of finite codimensional exact controllability for evolution equations. It is shown that this new controllability is equivalent ... More
Gauss-Bonnet coupling constant as a free thermodynamical variable and the associated criticalityNov 13 2013May 12 2014The thermodynamic phase space of Gauss-Bonnet (GB) AdS black holes is extended, taking the inverse of the GB coupling constant as a new thermodynamic pressure $P_{\mathrm{GB}}$. We studied the critical behavior associated with $P_{\mathrm{GB}}$ in the ... More
Parameter Estimation of Jelinski-Moranda Model Based on Weighted Nonlinear Least Squares and HeteroscedasticityFeb 28 2015Parameter estimation method of Jelinski-Moranda (JM) model based on weighted nonlinear least squares (WNLS) is proposed. The formulae of resolving the parameter WNLS estimation (WNLSE) are derived, and the empirical weight function and heteroscedasticity ... More
A Robust Alternating Direction Method for Constrained Hybrid Variational Deblurring ModelAug 31 2013Oct 02 2013In this work, a new constrained hybrid variational deblurring model is developed by combining the non-convex first- and second-order total variation regularizers. Moreover, a box constraint is imposed on the proposed model to guarantee high deblurring ... More
Mechanism for linear preferential attachment in growing networksAug 20 2007The network properties of a graph ensemble subject to the constraints imposed by the expected degree sequence are studied. It is found that the linear preferential attachment is a fundamental rule, as it keeps the maximal entropy in sparse growing networks. ... More
The Local Structure of Lie BialgebroidsOct 07 2002We study the local structure of Lie bialgebroids at regular points. In particular, we classify all transitive Lie bialgebroids. In special cases, they are connected to classical dynamical $r$-matrices and matched pairs induced by Poisson group actions ... More
Greedy Criterion in Orthogonal Greedy LearningApr 20 2016Orthogonal greedy learning (OGL) is a stepwise learning scheme that starts with selecting a new atom from a specified dictionary via the steepest gradient descent (SGD) and then builds the estimator through orthogonal projection. In this paper, we find ... More
Evaluating Semantic Rationality of a Sentence: A Sememe-Word-Matching Neural Network based on HowNetSep 11 2018Automatic evaluation of semantic rationality is an important yet challenging task, and current automatic techniques cannot well identify whether a sentence is semantically rational. The methods based on the language model do not measure the sentence by ... More
Initial orientation effect and selecting desired events in 520AMeV/u U-U collisionsNov 19 2008How to select out those collisions with the desired geometry such as tip-tip and/or body-body in experiment is one key point for performing high energy UU collisions. With a relativistic transport model, we performed a simulation for deformed UU collision ... More
An Energetic Variational Approach for ion transportAug 18 2014Oct 13 2014The transport and distribution of charged particles are crucial in the study of many physical and biological problems. In this paper, we employ an Energy Variational Approach to derive the coupled Poisson-Nernst-Planck-Navier-Stokes system. All physics ... More
Understanding the Characteristics of Internet Short Video Sharing: YouTube as a Case StudyJul 25 2007Established in 2005, YouTube has become the most successful Internet site providing a new generation of short video sharing service. Today, YouTube alone comprises approximately 20% of all HTTP traffic, or nearly 10% of all traffic on the Internet. Understanding ... More
Local Rademacher Complexity for Multi-label LearningOct 26 2014We analyze the local Rademacher complexity of empirical risk minimization (ERM)-based multi-label learning algorithms, and in doing so propose a new algorithm for multi-label learning. Rather than using the trace norm to regularize the multi-label predictor, ... More
Polarimetric Convolutional Network for PolSAR Image ClassificationJul 09 2018The approaches for analyzing the polarimetric scattering matrix of polarimetric synthetic aperture radar (PolSAR) data have always been the focus of PolSAR image classification. Generally, the polarization coherent matrix and the covariance matrix obtained ... More
Constructing Intrinsic Delaunay Triangulations from the Dual of Geodesic Voronoi DiagramsMay 21 2015Intrinsic Delaunay triangulation (IDT) is a fundamental data structure in computational geometry and computer graphics. However, except for some theoretical results, such as existence and uniqueness, little progress has been made towards computing IDT ... More
J/psi elliptic flow in relativistic heavy ion collisionsOct 06 2009The J/psi elliptic flow in high energy nuclear collisions is calculated in a transport model. While the flow is very small at SPS and RHIC energies, it is strongly enhanced at LHC energy due to the dominance of the regeneration mechanism.
Event Anisotropy in High Energy Nucleus-Nucleus CollisionsJul 07 1998The predictions of event anisotropy parameters from transport model RQMD are compared with the recent experimental measurements for 158$A$ GeV Pb+Pb collisions. Using the same model, we study the time evolution of event anisotropy at 2$A$ GeV and 158$A$ ... More
Detecting top-Higgs at high energy $e^{+}e^{-}$ collidersApr 30 2001We calculate the contributions of the top-Higgs $h_{t}^{0}$ predicted by topcolor assisted technicolor(TC2) models to $e^{+}e^{-}\longrightarrow \overline{t}c\overline{\nu}_{e}\nu_{e}$ and compare the results with the contributions of $h^{0}_{t}$ to the ... More
Iterative-Promoting Variable Step-size Least Mean Square Algorithm For Adaptive Sparse Channel EstimationApr 13 2015Least mean square (LMS) type adaptive algorithms have attracted much attention due to their low computational complexity. In the scenarios of sparse channel estimation, zero-attracting LMS (ZA-LMS), reweighted ZA-LMS (RZA-LMS) and reweighted -norm LMS ... More
Compressible Air Entrapment in High-Speed Drop Impacts on Solid SurfacesNov 27 2012Using high-speed photography coupled with optical interference, we experimentally study the air entrapment during a liquid drop impacting a solid substrate. We observe the formation of a compressed air film before the liquid touches the substrate, with ... More
SQLNet: Generating Structured Queries From Natural Language Without Reinforcement LearningNov 13 2017Synthesizing SQL queries from natural language is a long-standing open problem and has been attracting considerable interest recently. Toward solving the problem, the de facto approach is to employ a sequence-to-sequence-style model. Such an approach ... More
Exact Subspace Segmentation and Outlier Detection by Low-Rank RepresentationSep 08 2011Mar 30 2014In this work, we address the following matrix recovery problem: suppose we are given a set of data points containing two parts, one part consists of samples drawn from a union of multiple subspaces and the other part consists of outliers. We do not know ... More
Grid-converged Solution and Analysis of the Unsteady Viscous Flow in a Two-dimensional Shock TubeMay 25 2017The flow in a shock tube is extremely complex with dynamic multi-scale structures of sharp fronts, flow separation, and vortices due to the interaction of the shock wave, the contact surface, and the boundary layer over the side wall of the tube. Prediction ... More
Improved Recurrent Neural Networks for Session-based RecommendationsJun 27 2016Sep 16 2016Recurrent neural networks (RNNs) were recently proposed for the session-based recommendation task. The models showed promising improvements over traditional recommendation approaches. In this work, we further study RNN-based models for session-based recommendations. ... More
Convergence of Finite Difference Methods for Poisson's Equation with InterfacesAug 17 2001In this paper, a weak formulation of the discontinuous variable coefficient Poisson equation with interfacial jumps is studied. The existence, uniqueness and regularity of solutions of this problem are obtained. It is shown that the application of the ... More
Multiuser MISO Beamforming for Simultaneous Wireless Information and Power TransferMar 08 2013Jul 15 2014Simultaneous wireless information and power transfer (SWIPT) is anticipated to have abundant applications in future machine or sensor based wireless networks by providing wireless data and energy access at the same time. In this paper, we study a multiuser ... More
Novel rotating hairy black hole in (2+1)-dimensionsMay 26 2013Jun 03 2013We present some novel rotating hairy black hole metric in $(2+1)$ dimensions, which is an exact solution to the field equations of the Einstein-scalar-AdS theory with a non-minimal coupling. The scalar potential is determined by the metric ansatz and ... More
Accelerating BTZ spacetimeNov 03 2011Jun 13 2012An exact solution of $(2+1)$-dimensional Einstein gravity with cosmological constant is studied. The corresponding spacetime is interpreted as an accelerating BTZ spacetime. The proper acceleration, horizon structure, temperature and entropy are presented ... More
Accelerating vacua in Gauss-Bonnet gravityOct 26 2011Dec 07 2011Accelerating vacua with maximally symmetric, but not necessarily spherical, sections for Einstein and Gauss-Bonnet gravities in generic dimensions are obtained. The acceleration parameter has the effect of shifting the cosmological constants in Einstein ... More
Three dimensional rotating hairy black holes, asymptotics and thermodynamicsJun 27 2014A rotating hairy black hole solution is found in gravity minimally coupled to a self-interacting real scalar field in three spacetime dimensions. Then we discuss analytically the horizon structure and find an analogue of the famous Kerr bound in (2+1) ... More
Directed flow in an extended multiphase transport modelAug 24 2018We have studied the rapidity-odd directed flow in $^{197}$Au+$^{197}$Au collisions in the beam energy range from $\sqrt{s_{NN}}$ = 7.7 to 39 GeV within the framework of an extended multiphase transport model with both partonic and hadronic mean-field ... More
A Multilevel Sampling Method for Detecting Sources in a Stratified Ocean WaveguideFeb 16 2016In the reconstruction process of sound waves in a 3D stratified waveguide, a key technique is to effectively reduce the huge computational demand. In this work, we propose an efficient and simple multilevel reconstruction method to help locate the accurate ... More
Depletion induced like-charge attraction: Understanding from a self-consistent field model with dielectric effectJul 17 2015Mar 19 2016Electrostatic correlation and dielectric effects are of significant importance in ionic structure properties near charged surfaces. These effects can be modeled by a system of self-consistent field equations with the approximate potential of mean force ... More
On a Modified DeGroot-Friedkin Model of Opinion DynamicsMar 13 2015Feb 29 2016This paper studies the opinion dynamics that result when individuals consecutively discuss a sequence of issues. Specifically, we study how individuals' self-confidence levels evolve via a reflected appraisal mechanism. Motivated by the DeGroot-Friedkin ... More
Wyner's Common Information: Generalizations and A New Lossy Source Coding InterpretationJan 10 2013Wyner's common information was originally defined for a pair of dependent discrete random variables. Its significance is largely reflected in, hence also confined to, several existing interpretations in various source coding problems. This paper attempts ... More
An Alternative Analysis of Discontinuous Galerkin Method for Hyperbolic Conservation LawJan 16 2016Jan 19 2016The development and application of the Discontinuous Galerkin (DG) method have attracted great attention in computational fluid dynamics (CFD) com- munity in the past decades. The underlying reason for such an intensive investigation is due to favorable ... More
Dirac structures and Poisson homogeneous spacesNov 08 1996Poisson homogeneous spaces for Poisson groupoids are classfied in terms of Dirac structures for the corresponding Lie bialgebroids. Applications include Drinfel'd's classification in the case of Poisson groups and a description of leaf spaces of foliations ... More
Extremely Metal-Poor Star Candidates in the SDSSNov 06 2012For a sample of metal-poor stars (-3.3< [Fe/H] <-2.2) that have high-resolution spectroscopic abundance determinations, we have measured equivalent widths (EW) of the Ca II K, Mg I b and near-infrared (NIR) Ca II triplet lines using low-resolution spectra ... More
Acceleration of Primal-Dual Methods by Preconditioning and Simple Subproblem ProceduresNov 21 2018Jan 08 2019Primal-Dual Hybrid Gradient (PDHG) and Alternating Direction Method of Multipliers (ADMM) are two widely-used first-order optimization methods. They reduce a difficult problem to simple subproblems, so they are easy to implement and have many applications. ... More
Energetically stable discretizations for charge carrier transport and electrokinetic modelsMar 15 2015A finite element discretization using a method of lines approached is proposed for approximately solving the Poisson-Nernst-Planck (PNP) equations. This discretization scheme enforces positivity of the computed solutions, corresponding to particle density ... More
An Internal Observability Estimate for Stochastic Hyperbolic EquationsNov 03 2015Jan 18 2016This paper is addressed to establishing an internal observability estimate for some linear stochastic hyperbolic equations. The key is to establish a new global Carleman estimate for forward stochastic hyperbolic equations in the $L^2$-space. Different ... More
Covert Communication with A Full-Duplex Receiver Based on Channel Distribution InformationOct 12 2018Nov 10 2018In this work, we consider a system of covert communication with the aid of a full-duplex (FD) receiver to enhance the performance in a more realistic scenario, i.e., only the channel distribution information (CDI) rather than channel state information ... More
simNet: Stepwise Image-Topic Merging Network for Generating Detailed and Comprehensive Image CaptionsAug 27 2018The encode-decoder framework has shown recent success in image captioning. Visual attention, which is good at detailedness, and semantic attention, which is good at comprehensiveness, have been separately proposed to ground the caption on the image. In ... More
Multi-Task Learning for Machine Reading ComprehensionSep 18 2018We propose a multi-task learning framework to jointly train a Machine Reading Comprehension (MRC) model on multiple datasets across different domains. Key to the proposed method is to learn robust and general contextual representations with the help of ... More
Dynamic Fusion Networks for Machine Reading ComprehensionNov 14 2017Feb 26 2018This paper presents a novel neural model - Dynamic Fusion Network (DFN), for machine reading comprehension (MRC). DFNs differ from most state-of-the-art models in their use of a dynamic multi-strategy attention process, in which passages, questions and ... More
Alternative Awaiting and Broadcast for Two-Way Relay Fading ChannelsSep 06 2011Feb 03 2013We investigate a two-way relay (TWR) fading channel where two source nodes wish to exchange information with the help of a relay node. Given traditional TWR protocols, transmission rates in both directions are known to be limited by the hop with lower ... More
Shear induced solidification of athermal systems with weak attractionMar 08 2016We find that unjammed packings of frictionless particles with rather weak attraction can always be driven into solid-like states by shear. The structure of shear-driven solids evolves continuously with packing fraction from gel-like to jamming-like, but ... More
Cooperative Tx/Rx Caching in Interference Channels: A Storage-Latency Tradeoff StudyMay 25 2016This paper studies the storage-latency tradeoff in the $3\times3$ wireless interference network with caches equipped at all transmitters and receivers. The tradeoff is characterized by the so-called fractional delivery time (FDT) at given normalized transmitter ... More
QCD phase diagram and locating critical point using RHIC low energy scan dataFeb 28 2009It is shown that the RHIC energy-scan experiments can serve as an effective tool for studying the system evolution along the first order phase transition line passing the critical point, which is a second order phase transition process. During this process ... More
Topcolor assisted technicolor models and muon anomalous magnetic momentMar 08 2001Jun 09 2001We discuss and estimate the contributions of the new particles predicted by topcolor assisted technicolor(TC2) models to the muon anomalous magnetic moment $a_{\mu}$. Our results show that the contributions of Pseudo Goldstone bosons are very small which ... More
Using (4+1) split and energy conditions to study the induced matter in 5D Ricc-flat cosmologyOct 19 2006We use $(4+1)$ split to derive the 4D induced energy density $\rho $ and pressure $p$ of the $5D$ Ricci-flat cosmological solutions which are characterized by having a bounce instead of a bang. The solutions contain two arbitrary functions of time $t$ ... More
Reconstruction of Five-dimensional Bounce cosmological Models From Deceleration FactorJan 20 2006In this paper, we consider a class of five-dimensional Ricci-flat vacuum solutions, which contain two arbitrary functions $\mu(t)$ and $\nu(t)$. It is shown that $\mu(t)$ can be rewritten as a new arbitrary function $f(z)$ in terms of redshift $z$ and ... More
Understanding depletion induced like-charge attraction from self-consistent field modelJul 17 2015Nov 05 2016The interaction force between likely charged particles/surfaces is usually repulsive due to the Coulomb interaction. However, the counterintuitive like-charge attraction in electrolytes has been frequently observed in experiments, which has been theoretically ... More
Joint Representation Learning of Text and Knowledge for Knowledge Graph CompletionNov 13 2016Joint representation learning of text and knowledge within a unified semantic space enables us to perform knowledge graph completion more accurately. In this work, we propose a novel framework to embed words, entities and relations into the same continuous ... More
Second-order temporal interference of two independent light beams at an asymmetrical beam splitterAug 29 2016The second-order temporal interference of classical and nonclassical light at an asymmetrical beam splitter is discussed based on two-photon interference in Feynman's path integral theory. The visibility of the second-order interference pattern is determined ... More
Correspondence Between $5D$ Ricci-Flat Cosmological Models and Quintessence Dark Energy ModelsJul 18 2005Dec 26 2005We study the accelerating expansion and the induced dark energy of the $5D$ Ricci-flat universe which is characterized by having a big bounce as opposed to a big bang. We show that the arbitrary function $\mu(t)$ contained in the $5D$ solutions can be ... More
The polar decomposition for adjointable operators on Hilbert $C^*$-modules and centered operatorsJul 03 2018Jul 12 2018Let $T$ be an adjointable operator between two Hilbert $C^*$-modules and $T^*$ be the adjoint operator of $T$. The polar decomposition of $T$ is characterized as $T=U(T^*T)^\frac12$ and $\mathcal{R}(U^*)=\overline{\mathcal{R}(T^*)}$, where $U$ is a partial ... More
Direct determination of the size of basins of attraction of jammed solidsJan 31 2011Jun 28 2011We propose a free-energy based Monte-Carlo method to measure the volume of potential-energy basins in configuration space. Using this approach we can estimate the number of distinct potential-energy minima, even when this number is much too large to be ... More
Simplification of the Flux Function for a Higher-order Gas-kinetic Evolution ModelOct 04 2016The higher-order gas-kinetic scheme for solving the Navier-Stokes equations has been studied in recent years. In addition to the use of higher-order reconstruction techniques, many terms are used in the Taylor expansion of the gas distribution functions. ... More
Cell Size Effect on Computational Fluid Dynamics: The Limitation Principle for Flow SimulationJun 26 2017May 25 2018For theoretical gas dynamics, the flow regimes are classified according to the Knudsen number. For computational fluid dynamics (CFD), the numerical flow field is the projection of the physical flow field onto the discrete space and time, which is related ... More
Landau meets Newton: time translation symmetry breaking in classical mechanicsAug 29 2012Aug 31 2012Every classical Newtonian mechanical system can be equipped with a nonstandard Hamiltonian structure, in which the Hamiltonian is the square of the canonical Hamiltonian up to a constant shift, and the Poisson bracket is nonlinear. In such a formalism, ... More
Novel accelerating Einstein vacua and smooth inhomogeneous Riemannian manifoldsJun 13 2012Jun 14 2012A novel class of Einstein vacua is presented, which possess non-vanishing cosmological constant and accelerating horizon with the topology of $S^{D-3}$ fibration over $S^{1}$. After Euclideanization, the solution describes a conformally distorted $S^{D-1}$ ... More
A reciprocal branching problem for automorphic representations and global Vogan packetsDec 07 2018Let $G$ be a group and $H$ be a subgroup of $G$. The classical branching rule (or symmetry breaking) asks: For an irreducible representation $\pi$ of $G$, determine the occurrence of an irreducible representation $\sigma$ of $H$ in the restriction of ... More
Giant Faraday rotation induced by Berry phase in bilayer graphene under strong terahertz fieldsJul 30 2013High-order terahertz (THz) sideband generation (HSG) in semiconductors is a phenomenon with physics similar to high-order harmonic generation but in a much lower frequency regime. It was found that the electron-hole pairs excited by a weak optical laser ... More
A Revisit of the Masuda FlareMay 27 2009Mar 15 2010We revisit the flare on 1992 January 13, which is now universally termed the "Masuda flare". The revisit is motivated not only by its uniqueness despite accumulating observations of \hxr coronal emission, but also by the improvement of Yohkoh hard X-ray ... More
State-Continuity Approximation of Markov Decision Processes via Finite Element Analysis for Autonomous System PlanningMar 03 2019Motion planning under uncertainty for an autonomous system can be formulated as a Markov Decision Process. In this paper, we propose a solution to this decision theoretic planning problem using a continuous approximation of the underlying discrete value ... More
Global Well-posedness of the Two Dimensional Beris-Edwards System with General Laudau-de Gennes Free EnergyOct 23 2018In this paper, we consider the Beris-Edwards system for incompressible nematic liquid crystal flows. The system under investigation consists of the Navier-Stokes equations for the fluid velocity $\mathbf{u}$ coupled with an evolution equation for the ... More
Locally Removable Singularities for Kähler Metrics with Constant Holomorphic Sectional CurvatureDec 31 2018Let $n\ge 2$ be an integer, and $B^{n}\subset \mathbb{C}^{n}$ the unit ball. $K\subset B^{n}$ is a compact subset or $K=\{z=(z_1,\cdots, z_n)|z_1=z_2=0\}\subset \mathbb{C}^{n}$. By the theory of developing maps, we prove that a K\"{a}hler metric on $B^{n}\setminus ... More
The Common Information of N Dependent Random VariablesOct 18 2010This paper generalizes Wyner's definition of common information of a pair of random variables to that of $N$ random variables. We prove coding theorems that show the same operational meanings for the common information of two random variables generalize ... More
A quantum secret sharing scheme among three parties ultilizing four-qubit Smolin bound entangled stateMay 26 2006May 28 2006Four-qubit Smolin bound entangled state has a distinct feature: the state is not distillable when every qubit is seperated from each other; but it makes two separated qubit entangled if the other qubits group together. Here the feature is applied to quantum ... More
The influence of Chunking on Dependency Crossing and DistanceSep 03 2015This paper hypothesizes that chunking plays important role in reducing dependency distance and dependency crossings. Computer simulations, when compared with natural languages,show that chunking reduces mean dependency distance (MDD) of a linear sequence ... More
A Weighted Common Subgraph Matching AlgorithmNov 04 2014We propose a weighted common subgraph (WCS) matching algorithm to find the most similar subgraphs in two labeled weighted graphs. WCS matching, as a natural generalization of the equal-sized graph matching or subgraph matching, finds wide applications ... More
Signature of non-Markovianity in time-resolved energy transferJan 17 2017Jan 18 2017We explore signatures of the non-Markovianity in the time-resolved energy transfer processes for quantum open systems. Focusing on typical systems such as the exact solvable damped Jaynes-Cummings model and the general spin-boson model, we establish quantitative ... More
Green's functions for spin boson systems: Beyond conventional perturbation theoriesAug 17 2016Unraveling general properties of Green's functions of quantum dissipative systems is of both experimental relevance and theoretical interest. Here, we study the spin-boson model as a prototype. By utilizing the Majorana- Fermion representation together ... More
Boundary regularity for the second boundary-value problem of Monge-Ampère equations in dimension twoJun 25 2018In this paper, we introduce an iteration argument to prove that a convex solution to the Monge-Amp\`ere equation $\mbox{det } D^2 u =f $ in dimension two subject to the natural boundary condition $Du(\Omega) = \Omega^*$ is $C^{2,\alpha}$ smooth up to ... More
New multiplicative perturbation bounds for the generalized polar decompositionJul 09 2018Some new Frobenius norm bounds of the unique solution to certain structured Sylvester equation are derived. Based on the derived norm upper bounds, new multiplicative perturbation bounds are provided both for subunitary polar factors and positive semi-definite ... More