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Results for "Xiaoxi Liu"

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A microwave field-driven transistor-like skyrmionic device with the microwave current-assisted skyrmion creationJan 21 2016Oct 03 2017Magnetic skyrmion is a topologically protected domain-wall structure at nanoscale, which could serve as a basic building block for advanced spintronic devices. Here, we propose a microwave field-driven skyrmionic device with the transistor-like function, ... More
Skyrmion dynamics in a frustrated ferromagnetic film and current-induced helicity locking-unlocking transitionMar 22 2017Nov 23 2017The helicity-orbital coupling is an intriguing feature of magnetic skyrmions in frustrated magnets. Here, we explore the skyrmion dynamics in a frustrated magnet based on the $J_{1}$-$J_{2}$-$J_{3}$ classical Heisenberg model explicitly by including the ... More
Manipulation of magnetic skyrmions in a locally modified synthetic antiferromagnetic racetrackJul 18 2018Mar 07 2019In skyrmion-based racetrack memories, the information encoded by skyrmions may be destroyed due to the skyrmion Hall effect, which can be surmounted by using synthetic antiferromagnetic racetracks. Hence, the manipulation of skyrmions in synthetic antiferromagnetic ... More
Current-Driven Dynamics of Frustrated Skyrmions in a Synthetic Antiferromagnetic BilayerDec 03 2018Mar 27 2019We report the current-driven dynamics of frustrated skyrmions in an antiferromagnetically exchange coupled bilayer system, where the bilayer skyrmion consists of two monolayer skyrmions with opposite skyrmion numbers $Q$. We show that the in-plane current-driven ... More
Dynamics of the antiferromagnetic skyrmion induced by a magnetic anisotropy gradientAug 27 2018Oct 09 2018The dynamics of antiferromagnets is a current hot topic in condensed matter physics and spintronics. However, the dynamics of insulating antiferromagnets cannot be excited by an electric current, which is a method usually used to manipulate ferromagnetic ... More
Spin torque nano-oscillators based on antiferromagnetic skyrmionsNov 07 2018Skyrmion-based spin torque nano-oscillators are potential next-generation microwave signal generators. However, ferromagnetic skyrmion-based spin torque nano-oscillators cannot reach high oscillation frequencies. In this work, we propose to use the circular ... More
Gate-controlled reversible rectifying behaviour in tunnel contacted atomically-thin MoS$_{2}$ transistorApr 21 2017May 12 2017Atomically-thin 2D semiconducting materials integrated into van der Waals heterostructures have enabled architectures that hold great promise for next generation nanoelectronics. However, challenges still remain to enable their full acceptance as compliant ... More
Dynamics of magnetic skyrmion clusters driven by spin-polarized current with a spatially varied polarizationJan 26 2018Apr 06 2018Magnetic skyrmions are promising candidates for future information technology. Here, we present a micromagnetic study of isolated skyrmions and skyrmion clusters in ferromagnetic nanodisks driven by the spin-polarized current with spatially varied polarization. ... More
Deterministic creation and deletion of a single magnetic skyrmion observed by direct time-resolved X-ray microscopyJun 21 2017Apr 06 2018Spintronic devices based on magnetic skyrmions are a promising candidate for next-generation memory applications due to their nanometre-size, topologically-protected stability and efficient current-driven dynamics. Since the recent discovery of room-temperature ... More
Uniform value for some nonexpansive optimal control problems with general evaluationsMar 12 2016We study the long-run properties of optimal control problems in continuous time, where the running cost of a control problem is evaluated by a probability measure over R_+. Li, Quincampoix and Renault [DCDS-A, 2016] introduced an asymptotic regularity ... More
Motion of skyrmions in nanowires driven by magnonic momentum-transfer forcesJan 10 2017Jun 06 2017We study the motion of magnetic skyrmions in a nanowire induced by a spin-wave current $J$ flowing out of a driving layer close to the edge of the wire. By applying micromagnetic simulation and an analysis of the effective Thiele equation, we find that ... More
Asymptotic Properties of Neural Network Sieve EstimatorsJun 03 2019Neural networks are one of the most popularly used methods in machine learning and artificial intelligence nowadays. Due to the universal approximation theorem (Hornik et al. (1989)), a neural network with one hidden layer can approximate any continuous ... More
Magnetic Skyrmion Transport in a Nanotrack With Spatially Varying Damping and Non-adiabatic TorqueJul 18 2016Dec 15 2016Reliable transport of magnetic skyrmions is required for any future skyrmion-based information processing devices. Here we present a micromagnetic study of the in-plane current-driven motion of a skyrmion in a ferromagnetic nanotrack with spatially sinusoidally ... More
Control and manipulation of a magnetic skyrmionium in nanostructuresApr 20 2016Sep 03 2016A magnetic skyrmionium is a nontopological soliton, which has a doughnut-like out-of-plane spin texture in thin films, and can be phenomenologically viewed as a coalition of two topological magnetic skyrmions with opposite topological numbers. Due to ... More
Magnetic skyrmion transport in a nanotrack with spatially varying damping and non-adiabatic torqueJul 18 2016Oct 01 2016Reliable transport of magnetic skyrmions is required for future skyrmion-based information processing devices. We present a micromagnetic study of the in-plane current-driven motion of a skyrmion in a ferromagnetic nanotrack with spatially sinusoidally ... More
Current-driven dynamics of frustrated skyrmions in a synthetic antiferromagnetic bilayerDec 03 2018Magnetic skyrmions can be stabilized and manipulated in frustrated magnets, and are useful for building nonvolatile magnetic memories and logic devices. Here we study the current-driven dynamics of frustrated skyrmions in an antiferromagnetically exchange ... More
Dynamics of a magnetic skyrmionium driven by spin wavesFeb 12 2018Mar 23 2018The magnetic skyrmionium is a skyrmion-like structure but carries a zero net skyrmion number, which can be used as a building block for non-volatile information processing devices. Here, we study the dynamics of a magnetic skyrmionium driven by propagating ... More
Manipulation of magnetic skyrmions in a locally modified synthetic antiferromagnetic racetrackJul 18 2018In skyrmion-based racetrack-type memory devices, the information encoded by magnetic skyrmions may be destroyed due to the skyrmion Hall effect, which can be surmounted by using synthetic antiferromagnetic racetracks. Hence, the manipulation of skyrmions ... More
Voltage-Driven High-Speed Skyrmion Motion in a Skyrmion Shift DeviceMar 15 2018Magnetic skyrmions are promising information carriers for building future high-density and high-speed spintronic devices. However, to achieve a current-driven high-speed skyrmion motion, the required driving current density is usually very large, which ... More
Recursive games: Uniform value, Tauberian theorem and the Mertens conjecture "$Maxmin=\lim v_n=\lim v_λ$"Jun 02 2015We study two-player zero-sum recursive games with a countable state space and finite action spaces at each state. When the family of $n$-stage values $\{v_n,n\geq 1\}$ is totally bounded for the uniform norm, we prove the existence of the uniform value. ... More
Uniform Value for Recursive Games with Compact ActionsApr 12 2016Mertens, Neyman and Rosenberg [MOR, 2009] used the Mertens and Neyman theorem [IJGT, 1981] to prove the existence of uniform value for absorbing games with finite state space and compact action sets. We provide an analogous proof for another class of ... More
Magnetic skyrmion transistor operated with microwavesJan 21 2016Aug 20 2016Magnetic skyrmion is a topologically protected magnetic domain-wall structure at nanoscale, which might be a basic building block for advanced spintronic devices. Here, we propose the microwave-driven motion of a magnetic skyrmion in a voltage-gated nanotrack, ... More
Current-Induced Dynamics and Chaos of an Antiferromagnetic BimeronMay 22 2019Magnetic bimeron is a topologically non-trivial spin texture carrying an integer topological charge, which can be regarded as the counterpart of skyrmion in easy-plane magnets. The controllable creation and manipulation of bimerons are crucial for practical ... More
Dynamics of magnetic skyrmion clusters driven by spin-polarized current with a spatially varied polarizationJan 26 2018Feb 03 2018Magnetic skyrmions are promising candidates for future information technology. Here, we present a micromagnetic study of isolated skyrmions and skyrmion clusters in a ferromagnetic nanodisk driven by the spin-polarized current with spatially varied polarization. ... More
A decade of skyrmionics: Writing, deleting, reading and processing magnetic skyrmions toward spintronic applicationsJun 11 2019Jun 12 2019The field of skyrmionics has been actively investigated across a wide range of topics during the last decade. In this topical review, we review and discuss key results and findings in skyrmionics since the first experimental observation of magnetic skyrmions ... More
Generation and Hall effect of skyrmions enabled via using nonmagnetic point contactsFeb 19 2019To enable functional skyrmion based spintronic devices, the controllable generation and manipulation of skyrmions is essential. While the generation of skyrmions by using a magnetic geometrical constriction has already been demonstrated, this approach ... More
Electric field-induced creation and directional motion of domain walls and skyrmion bubblesAug 07 2017Dec 12 2018Magnetization dynamics driven by an electric field could provide long-term benefits to information technologies because of its ultralow power consumption. Meanwhile, the Dzyaloshinskii-Moriya interaction in interfacially asymmetric multilayers consisting ... More
Spin-Topology Dependent Brownian Diffusion of SkyrmionsJan 24 2019Non-interacting particles exhibiting Brownian motion have been observed in many occasions of sciences, such as molecules suspended in liquids, optically trapped microbeads, and spin textures in magnetic materials. In particular, a detailed examination ... More
A decade of skyrmionics: Writing, deleting, reading and processing magnetic skyrmions roward spintronic applicationsJun 11 2019The field of skyrmionics has been actively investigated across a wide range of topics during the last decade. In this topical review, we review and discuss key results and findings in skyrmionics since the first experimental observation of magnetic skyrmions ... More
Multi-Task Zipping via Layer-wise Neuron SharingMay 24 2018Mar 13 2019Future mobile devices are anticipated to perceive, understand and react to the world on their own by running multiple correlated deep neural networks on-device. Yet the complexity of these neural networks needs to be trimmed down both within-model and ... More
Limit value for optimal control with general meansMar 17 2015We consider optimal control problem with an integral cost which is a mean of a given function. As a particular case, the cost concerned is the Ces\`aro average. The limit of the value with Ces\`aro mean when the horizon tends to infinity is widely studied ... More
Porosity-mediated High-performance Thermoelectric MaterialsOct 08 2018Oct 11 2018Whether porosity can effectively improve thermoelectric performance is still an open question. Herein we report that thermoelectric performance can be significantly enhanced by creating porosity in n-type Mg3.225Mn0.025Sb1.5Bi0.49Te0.01, with a ZT of ... More
Detecting and Gauging Impact on Wikipedia Page ViewsMar 26 2019Understanding how various external campaigns or events affect readership on Wikipedia is important to efforts aimed at improving awareness and access to its content. In this paper, we consider how to build time-series models aimed at predicting page views ... More
A stochastic asymptotic-preserving scheme for the bipolar semiconductor Boltzmann-Poisson system with random inputs and diffusive scalingsFeb 26 2018Jul 16 2018In this paper, we study the bipolar Boltzmann-Poisson model, both for the deterministic system and the system with uncertainties, with asymptotic behavior leading to the drift diffusion-Poisson system as the Knudsen number goes to zero. The random inputs ... More
Recognize Foreign Low-Frequency Words with Similar PairsJun 16 2015Low-frequency words place a major challenge for automatic speech recognition (ASR). The probabilities of these words, which are often important name entities, are generally under-estimated by the language model (LM) due to their limited occurrences in ... More
Current-driven dynamics and inhibition of the skyrmion Hall effect of ferrimagnetic skyrmions in GdFeCo filmsMar 30 2017Jan 30 2018Magnetic skyrmions are swirling magnetic textures with novel characteristics suitable for future spintronic and topological applications. Recent studies confirmed the room-temperature stabilization of skyrmions in ultrathin ferromagnets. However, such ... More
Molecular dynamics with quantum heat baths: results for nanoribbons and nanotubesJul 19 2009A generalized Langevin equation with quantum baths (QMD) for thermal transport is derived with the help of nonequilibrium Green's function (NEGF) formulation. The exact relationship of the quasi-classical approximation to NEGF is demonstrated using Feynman ... More
Disentangling Redundancy for Multi-Task PruningMay 23 2019Can prior network pruning strategies eliminate redundancy in multiple correlated pre-trained deep neural networks? It seems a positive answer if multiple networks are first combined and then pruned. However, we argue that an arbitrarily combined network ... More
How Does Folding Modulate Thermal Conductivity of GrapheneJul 02 2012We study thermal transport in folded graphene nanoribbons using molecular dynamics simulations and the non-equilibrium Green's function method. It is found that the thermal conductivity of flat graphene nanoribbons can be modulated by folding and changing ... More
A Truthful $(1-ε)$-Optimal Mechanism for On-demand Cloud Resource ProvisioningNov 23 2016On-demand resource provisioning in cloud computing provides tailor-made resource packages (typically in the form of VMs) to meet users' demands. Public clouds nowadays provide more and more elaborated types of VMs, but have yet to offer the most flexible ... More
Current-driven magnetization switching in a van der Waals ferromagnet Fe3GeTe2Feb 15 2019The recent discovery of ferromagnetism in two-dimensional (2D) van der Waals (vdW) materials holds promises for novel spintronic devices with exceptional performances. However, in order to utilize 2D vdW magnets for building spintronic nanodevices such ... More
Gate tunable giant anisotropic resistance in ultra-thin GaTeJan 14 2019In crystals, the duplication of atoms often follows different periodicity along different directions. It thus gives rise to the so called anisotropy, which is usually even more pronounced in two dimensional (2D) materials due to the absence of $\textbf{z}$ ... More
Recovery of an embedded obstacle and its surrounding medium by formally-determined scattering dataOct 19 2016We consider an inverse acoustic scattering problem in simultaneously recovering an embedded obstacle and its surrounding inhomogeneous medium by formally determined far-field data. It is shown that the knowledge of the scattering amplitude with a fixed ... More
Recovery of an embedded obstacle and its surrounding medium by formally-determined scattering dataOct 19 2016Nov 10 2016We consider an inverse acoustic scattering problem in simultaneously recovering an embedded obstacle and its surrounding inhomogeneous medium by formally determined far-field data. It is shown that the knowledge of the scattering amplitude with a fixed ... More
Formula of Volume of Revolution with Integration by Parts and ExtensionSep 04 2016A calculation formula of volume of revolution with integration by parts of definite integral is derived based on monotone function, and extended to a general case that curved trapezoids is determined by continuous, piecewise strictly monotone and differential ... More
A class of cyclic codes whose dual have five zerosFeb 07 2015In this paper, a family of cyclic codes over $\mathbb{F}_{p}$ whose duals have five zeros is presented, where $p$ is an odd prime. Furthermore, the weight distributions of these cyclic codes are determined.
To Stay Or To Switch: Multiuser Dynamic Channel AccessSep 14 2013In this paper we study opportunistic spectrum access (OSA) policies in a multiuser multichannel random access cognitive radio network, where users perform channel probing and switching in order to obtain better channel condition or higher instantaneous ... More
An Online Approach to Dynamic Channel Access and Transmission SchedulingApr 04 2015Making judicious channel access and transmission scheduling decisions is essential for improving performance as well as energy and spectral efficiency in multichannel wireless systems. This problem has been a subject of extensive study in the past decade, ... More
TeV dark matter and the DAMPE electron excessNov 30 2017The recent high energy electron and positron flux observed by the DAMPE experiment indicates possible excess events near 1.4 TeV. Such an excess may be evidence of dark matter annihilations or decays in a dark matter subhalo that is located close to the ... More
On the arithmetic of the endomorphism ring End($\mathbb{Z}_{p}\times\mathbb{Z}_{p^{m}}$)May 03 2016For a prime $p$, let $E_{p,p^m}=\{\begin{pmatrix}a&b\\p^{m-1}c&d\end{pmatrix}|a,b,c\in\mathbb{Z}_{p},~\mathrm{and}~d\in \mathbb{Z}_{p^{m}}\}$. We first establish a ring isomorphism from $\mathrm{End}(\mathbb{Z}_p\times\mathbb{Z}_p^m)$ onto $E_{p,p^m}$. ... More
The Dynamic Behavior of Quantum Statistical Entropy in 5D Ricci-flat Black String with Thin-layer ApproachNov 05 2008In this paper, the statistical-mechanical entropies of 5D Ricci-flat black string is calculated through the wave modes of the quantum field with improved thin-layer brick-wall method. The modes along the fifth dimension are semi-classically quantized ... More
Fine Magnetic Characteristics of a Light Bridge by HinodeFeb 01 2019Light bridge (LB) is bright structure crossing the umbra of sunspots and associated to the breakup or assembly of sunspots. In this paper, a LB is presented and studied using the observatory data obtained by {\it Hinode} satellites. Force-free factor ... More
Relationship between Magnetic Field Properties and an X-class Flare in Active Region NOAA 9077Feb 01 2019The magnetic field plays a key role in producing solar flares, so that the investigation on the relationship between the magnetic field properties and flares is significant. In this paper, based on the magnetic field extrapolated from the photospheric ... More
Power Allocation for Secure SWIPT Systems with Wireless-Powered Cooperative JammingFeb 18 2017This paper considers wireless-powered cooperative jamming (CJ) to secure communication between a transmitter (Tx) and an information receiver (IR), in the presence of an energy receiver (ER) which is termed as a potential eavesdropper. The full-duplex ... More
$σ$-self-orthogonal constacyclic codes of length $p^s$ over $\mathbb F_{p^m}+u\mathbb F_{p^m}$Jul 25 2018In this paper, we study the $\sigma$-self-orthogonality of constacyclic codes of length $p^s$ over the finite commutative chain ring $\mathbb F_{p^m} + u \mathbb F_{p^m}$, where $u^2=0$ and $\sigma$ is a ring automorphism of $\mathbb F_{p^m} + u \mathbb ... More
A blow-up criterion for the compressible liquid crystals systemNov 19 2010Nov 23 2010In this paper, we establish a blow-up criterion for the compressible liquid crystals equations in terms of the gradient of the velocity only, similar to the Beale-Kato-Majda criterion \cite{majda} for ideal incompressible flows and the criterion obtained ... More
On surjectivity of smooth maps into Euclidean spaces and the fundamental theorem of algebraJun 16 2017In this note we obtain the surjectivity of smooth maps into Euclidean spaces under mild conditions. As application we give a new proof of the Fundamental Theorem of Algebra. We also observe that any $C^1$-map from a compact manifold into Euclidean space ... More
$T$-adic exponential sums of polynomials in one variableNov 03 2009The $T$-adic exponential sum of a polynomial in one variable is studied. An explicit arithmetic polygon in terms of the highest two exponents of the polynomial is proved to be a lower bound of the Newton polygon of the $C$-function of the T-adic exponential ... More
Elastic Waves Scattering without Conversion in Metamaterials with Simultaneous Zero Indices for Longitudinal and Transverse wavesMar 08 2015Sep 28 2015We theoretically investigate elastic waves propagating in metamaterials with simultaneous zero indices for both the longitudinal and transverse waves. With scattering objects (here cylinders) present in the metamaterials slabs, while the elastic waves ... More
Exploiting Unlabeled Data for Neural Grammatical Error DetectionNov 28 2016Nov 29 2016Identifying and correcting grammatical errors in the text written by non-native writers has received increasing attention in recent years. Although a number of annotated corpora have been established to facilitate data-driven grammatical error detection ... More
Non-Parametric Variational Inference with Graph Convolutional Networks for Gaussian ProcessesSep 08 2018Inference for GP models with non-Gaussian noises is computationally expensive when dealing with large datasets. Many recent inference methods approximate the posterior distribution with a simpler distribution defined on a small number of inducing points. ... More
Lending Orientation to Neural Networks for Cross-view Geo-localizationMar 29 2019This paper studies image-based geo-localization (IBL) problem using ground-to-aerial cross-view matching. The goal is to predict the spatial location of a ground-level query image by matching it to a large geotagged aerial image database (e.g., satellite ... More
The multiplier and cohomology of Lie superalgebrasNov 01 2018In this paper, all (super)algebras are over a field $\mathbb{F}$ of characteristic different from $2, 3$. We construct the so-called 5-sequences of cohomology for central extensions of a Lie superalgebra and prove that they are exact. Then we prove that ... More
Twisted exponential sums of polynomials in one variableDec 10 2009The twisted $T$-adic exponential sum associated to a polynomial in one variable is studied. An explicit arithmetic polygon in terms of the highest two exponents of the polynomial is proved to be a lower bound of the Newton polygon of the $C$-function ... More
Higher Toda Mechanics and Spectral CurvesJun 01 2003For each one of the Lie algebras $\mathfrak{gl}_{n}$ and $\widetilde {\mathfrak{gl}}_{n}$, we constructed a family of integrable generalizations of the Toda chains characterized by two integers $m_{+}$ and $m_{-}$. The Lax matrices and the equations of ... More
Group Learning and Opinion Diffusion in a Broadcast NetworkSep 14 2013We analyze the following group learning problem in the context of opinion diffusion: Consider a network with $M$ users, each facing $N$ options. In a discrete time setting, at each time step, each user chooses $K$ out of the $N$ options, and receive randomly ... More
Rapid variability of BL Lac 0925+504: interstellar scintillation induced?Apr 25 2018Analysis of rapid variability at 4.85 GHz for the BL BLac object 0925+504 is presented and discussed. The structure functions (SF) are investigated with both refractive and weak interstellar scintillation (RISS/WISS) models analytically. Parameters obtained ... More
Price-Based Distributed Offloading for Mobile-Edge Computing with Computation Capacity ConstraintsDec 02 2017Mobile-edge computing (MEC) is a promising technology to enable real-time information transmission and computing by offloading computation tasks from wireless devices to network edge.
On the $A_α$-characteristic polynomial of a graphNov 09 2017Let $G$ be a graph with $n$ vertices, and let $A(G)$ and $D(G)$ denote respectively the adjacency matrix and the degree matrix of $G$. Define $$ A_{\alpha}(G)=\alpha D(G)+(1-\alpha)A(G) $$ for any real $\alpha\in [0,1]$. The $A_{\alpha}$-characteristic ... More
Multi-Channel CNN-based Object Detection for Enhanced Situation AwarenessNov 30 2017Object Detection is critical for automatic military operations. However, the performance of current object detection algorithms is deficient in terms of the requirements in military scenarios. This is mainly because the object presence is hard to detect ... More
Wake Potential in Strong Coupling Plasma from AdS/CFT CorrespondenceFeb 06 2015With the dielectric function computed from AdS/CFT correspondence, we studied the wake potential induced by a fast moving charge in strong coupling plasma, and compared it with the weak coupling wake potential for different particle velocities as $v=0.55c$ ... More
Quantum Manifestation of Elastic Constants in NanostructuresSep 05 2012Generally, there are two distinct effects in modifying the properties of low-dimensional nanostructures: surface effect (SS) due to increased surface-volume ratio and quantum size effect (QSE) due to quantum confinement in reduced dimension. The SS has ... More
Derivations from the even parts into the odd parts for Lie superalgebras W and SSep 08 2005Let $\mathcal{W}$ and $\mathcal{S}$ denote the even parts of the general Witt superalgebra $W$ and the special superalgebra $S$ over a field of characteristic $ p>3,$ respectively. In this note, using the method of reduction on $\mathbb{Z}$-gradations, ... More
Discriminative Cross-View Binary Representation LearningApr 04 2018Learning compact representation is vital and challenging for large scale multimedia data. Cross-view/cross-modal hashing for effective binary representation learning has received significant attention with exponentially growing availability of multimedia ... More
Charge-then-Forward: Wireless Powered Communication for Multiuser Relay NetworksJun 26 2018This paper studies a relay-assisted wireless powered communication network (R-WPCN) consisting of multiple source-destination pairs and a hybrid relay node (HRN). We consider a "charge-then-forward" protocol at the HRN, in which the HRN with constant ... More
Maximal graded subalgebras of Witt and Special superalgebrasNov 18 2009Mar 08 2010This paper has been withdrawn by the author due to that the main results and approaches are closedly parallel to the ones in Lie algebra case.
Upper Beurling Density of Systems formed by Translates of finite Sets of Elements in $L^p(\R^d)$Mar 28 2012In this paper, we prove that if a finite disjoint union of translates $\bigcup_{k=1}^n\{f_k(x-\gamma)\}_{\gamma\in\Gamma_k}$ in $L^p(\R^d)$ $(1<p<\infty)$ is a $p'$-Bessel sequence for some $1<p'<\infty$, then the disjoint union $\Gamma=\bigcup_{k=1}^n\Gamma_k$ ... More
Hypocoercivity based Sensitivity Analysis and Spectral Convergence of the Stochastic Galerkin Approximation to Collisional Kinetic Equations with Multiple Scales and Random InputsSep 30 2017May 22 2018In this paper, we provide a general framework to study general class of linear and nonlinear kinetic equations with random uncertainties from the initial data or collision kernels, and their stochastic Galerkin approximations, in both incompressible Navier-Stokes ... More
Recovery of an embedded obstacle and its surrounding medium by formally-determined scattering dataOct 19 2016Jan 04 2017We consider an inverse acoustic scattering problem in simultaneously recovering an embedded obstacle and its surrounding inhomogeneous medium by formally determined far-field data. It is shown that the knowledge of the scattering amplitude with a fixed ... More
Duality-free Methods for Stochastic Composition OptimizationOct 26 2017We consider the composition optimization with two expected-value functions in the form of $\frac{1}{n}\sum\nolimits_{i = 1}^n F_i(\frac{1}{m}\sum\nolimits_{j = 1}^m G_j(x))+R(x)$, { which formulates many important problems in statistical learning and ... More
On a Qualitative Difference between the Dynamics of Particle Production in Soft and Hard Processes of High Energy CollisionsDec 10 1998The qualitative difference between the anomalous scaling properties of hadronic final states in soft and hard processes of high energy collisions is studied in some detail. It is pointed out that the experimental data of e^+e^- collisions at $E_{cm}=$91.2 ... More
Lecture notes on thermodynamics of ideal string gases and its application in cosmologyDec 05 2014In these lecture notes I give a pedagogical introduction to the thermodynamics of ideal string gases. The computation of thermodynamic quantities in the canonical ensemble formalism will be shown in detail with explicit examples. Attention will be given ... More
Holographic renormalization in no-boundary quantum cosmologyDec 04 2014Dec 22 2014Recent results of Hartle-Hawking wave functions on asymptotic dS boundaries show non-normalizability, while the bulk origin is not clear. This paper attempts to addresse this problem by studying (Kerr-)dS_3 cosmology in Einstein gravity deformed by a ... More
Extracting the trustworthiest way to service provider in complex online social networksJun 18 2013In complex online social networks, it is crucial for a service consumer to extract the trustworthiest way to a target service provider from numerous social trust paths between them. The extraction of the trustworthiest way (namely, optimal social trust ... More
Robust Particle Filter by Dynamic Averaging of Multiple Noise ModelsSep 05 2016State filtering is a key problem in many signal processing applications. From a series of noisy measurement, one would like to estimate the state of some dynamic system. Existing techniques usually adopt a Gaussian noise assumption which may result in ... More
The intrinsic line width of the Fe Ka line of AGNAug 26 2016X-ray fluorescent lines are unique features of the reflection spectrum of the cold torus when irradiated by the central AGN. Their intrinsic line widths can be used to probe the line-emitting region. The line widths of the Fe \Ka line measured from the ... More
Noise-Sustained Convective Instability in a Magnetized Taylor-Couette FlowAug 19 2008Oct 13 2008The helical magnetorotational instability of the magnetized Taylor-Couette flow is studied numerically in a finite cylinder. A distant upstream insulating boundary is shown to stabilize the convective instability entirely while reducing the growth rate ... More
Magnetized Ekman Layer and Stewartson Layer in a Magnetized Taylor-Couette FlowDec 15 2007Apr 26 2008In this paper we present axisymmetric nonlinear simulations of magnetized Ekman and Stewartson layers in a magnetized Taylor-Couette flow with a centrifugally stable angular-momemtum profile and with a magnetic Reynolds number below the threshold of magnetorotational ... More
Recent Results on Light Hadrons from the BESIII ExperimentSep 01 2015The BESIII experiment has collected world's largest direct $e^+e^-$ colliding beam data at the $J/\psi$, $\psi'$, $\psi$(3770) and at and around the $Y$(4260). These data have enabled the study of hadrons at unprecedented precisions. We present results ... More
q-conjugacy classes in loop groupsNov 23 2010We classify twisted conjugacy classes in loop groups, restricted to classical groups. The main tool we used is the so-called D_q module, an object which is related to vector bundles over elliptic curves.
A Simple Discussion on Wave Functional in Free QEDNov 18 2005Jun 18 2009This paper has been withdrawn by the author due to some mistakes
Estimates for Forward-backward Asymmetry in $B\rightarrow K^*(892)\; l^+ l^-$Jan 12 1995Jan 12 1995Forward-backward charge asymmetry in rare dilepton $B$-decays is formulated with the assumption of an on-shell b-quark. We find the asymmetry is expressed in terms of two spatially transverse helicity amplitudes, which are determined by combining the ... More
Uniqueness of scatterer in inverse acoustic obstacle scattering with a single incident plane waveOct 11 2016Oct 17 2016In this paper, we give a simple proof for uniqueness of the scatterer in inverse obstacle scattering problem for acoustic wave with a single incident plane wave. Ramm in \cite{Ram1} showed that the acoustic scattering amplitude $A(\beta, {\alpha}_0, k_0)$, ... More
Model-based Differential Private Data SynthesisJun 26 2016We propose model-based based differential private data synthesis (modips) for releasing individual-level data with strong privacy guarantee. The modips technique is an original framework to integrate differential privacy -- a concept discussed largely ... More
Bridge the gap between network-based inference method and global ranking method in personal recommendationJul 15 2015In this paper, we study the relationship between the network-based inference method and global ranking method in personal recommendation. By some theoretical analysis, we prove that the recommendation result under the global ranking method is the limit ... More
Mixture Diffusion for Asset PricingOct 05 2016Oct 12 2016This paper proposes a general form of mixture diffusion process to model asset price dynamics, using a mixture of infinite number of parametric diffusions. We show that the underlying asset price dynamics of the risk-neutral probability density distributions ... More
Uniqueness of scatterer in inverse acoustic obstacle scattering with a single incident plane waveOct 11 2016Oct 19 2016In this paper, we give a simple proof for uniqueness of the scatterer in inverse obstacle scattering problem for acoustic wave with a single incident plane wave. Ramm in \cite{Ram1} showed that the acoustic scattering amplitude $A(\beta, {\alpha}_0, k_0)$, ... More
Twisted K-homology,Geometric cycles and T-dualityNov 06 2014Nov 14 2014Twisted $K$-homology corresponds to $D$-branes in string theory. In this paper we compare two different models of geometric twisted $K$-homology and get their equivalence. Moreover, we give another description of geometric twisted $K$-homology using bundle ... More
Resolution for Sheaf of Differential Operators on Smooth Free Geometric Quotient of Linear Action of Algebraic GroupSep 13 1996Sep 16 1996We obtain a global resolution for the sheaf of differential operators on smooth geometric quotients of free linear actions of algebraic groups. The terms of our resolution involve symmetric and alternating powers of vector bundles easily constructed geometrically ... More
Necessary Conditions about the Diederich-Fornæss indexOct 20 2016We derive several necessary conditions about the Diederich-Forn\ae ss index. One of the main motivations in the article is to look for a necessary condition for the given bounded pseudoconvex domain $\Omega\subset\mathbb{C}^2$ with smooth boundary such ... More