Results for "Jian Xu"

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Long-time asymptotics for the short pulse equationAug 10 2016In this paper, we analyze the long-time behavior of the solution of the initial value problem (IVP) for the short pulse (SP) equation. As the SP equation is a complete integrable system, which posses a Wadati-Konno-Ichikawa (WKI)-type Lax pair, we formulate ... More
Statistical properties of electrochemical capacitance in disordered mesoscopic capacitorsJan 06 2017We numerically investigate the statistical properties of electrochemical capacitance in disordered two-dimensional mesoscopic capacitors. Based on the tight-binding Hamiltonian, the Green's function formalism is adopted to study the average electrochemical ... More
Mining Features Associated with Effective TweetsJun 22 2017What tweet features are associated with higher effectiveness in tweets? Through the mining of 122 million engagements of 2.5 million original tweets, we present a systematic review of tweet time, entities, composition, and user account features. We show ... More
The statistics of Wigner delay time in Anderson disordered systemsJan 17 2011We numerically investigate the statistical properties of Wigner delay time in Anderson disordered 1D, 2D and quantum dot (QD) systems. The distribution of proper delay time for each conducting channel is found to be universal in 2D and QD systems for ... More
Inversion of trace formulas for a Sturm-Liouville operatorJun 28 2019This paper revisits the classical problem "Can we hear the density of a string?", which can be formulated as an inverse spectral problem for a Sturm-Liouville operator. Based on inverting a sequence of trace formulas, we propose a new numerical scheme ... More
Localization for random walks among random obstacles in a single Euclidean ballJul 21 2018Nov 02 2018Place an obstacle with probability $1-p$ independently at each vertex of $\mathbb Z^d$, and run a simple random walk until hitting one of the obstacles. For $d\geq 2$ and $p$ strictly above the critical threshold for site percolation, we condition on ... More
The vortex dynamics of a Ginzburg-Landau system under pinning effectJan 10 2003It is proved that the vortices are attracted by impurities or inhomogeities in the superconducting materials. The strong H^1-convergence for the corresponding Ginzburg-Landau system is also proved.
The spin parity of $Z_c^-$(4100), $Z_1^+$(4050) and $Z_2^+$(4250)Nov 15 2018Aug 21 2019We conjecture that $Z_c^-$(4100) found by LHCb group from a Dalitz plot analysis of $B^0\to \eta_c K^+\pi^-$ decay is the charge conjugate of $Z_1^+$(4050) observed in $\chi_{c1}\pi^+$ distribution from Belle collaboration. Some interesting conclusions ... More
Moire Insulators viewed as the Surface of three dimensional Symmetry Protected Topological PhasesOct 08 2018Oct 11 2018Recently, correlated physics such as superconductivity and insulator at commensurate fractional electron fillings has been discovered in several different systems with Moire superlattice and narrow electron bands near charge neutrality. Before we learn ... More
Guarantees of Total Variation Minimization for Signal RecoveryJan 28 2013Oct 11 2013In this paper, we consider using total variation minimization to recover signals whose gradients have a sparse support, from a small number of measurements. We establish the proof for the performance guarantee of total variation (TV) minimization in recovering ... More
An abstract characterization of unital operator spacesMay 16 2008May 27 2008In this article, we give an abstract characterization of the ``identity'' of an operator space $V$ by looking at a quantity $n_{cb}(V,u)$ which is defined in analogue to a well-known quantity in Banach space theory. More precisely, we show that there ... More
A Unique Method to Determine SNe Initial Explosion EnergySep 02 2009Oct 18 2009There are several different methods to determine the individual supernovae (SNe) initial explosion energy, here we derive the average or typical explosion energy of shell-type supernova remnants (SNRs) in a particular way. By solving a group of equations ... More
Optimal entanglement generation in cavity QED with dissipationDec 23 2009We investigate a two-level atom coupled to a cavity with a strong classical driving field in a dissipative environment and find an analytical expression of the time evolution density matrix for the system. The analytical density operator is then used ... More
SafeZone: A Hierarchical Inter-Domain Authenticated Source Address Validation SolutionMar 19 2011Next generation Internet is highly concerned about the issue of reliability. Principally, the foundation of reliability is authentication of the source IP address. With the signature-and-verification based defense mechanisms available today, unfortunately, ... More
Generalized Surface Polaritons and their quantum spin Hall effectFeb 05 2016Surface polaritons, e.g., surface plasmon polaritons, are invaluable tools in nanophotonics. However, considerable plasmon loss narrows the application regime of plasmonic devices. Here we reveal some general conditions for lossless surface polaritons ... More
The unified transform method for the Sasa-Satsuma equation on the intervalDec 21 2015We present a Riemann-Hilbert problem formalism for the initial-boundary value problem for the Sasa-Satsuma(SS) equation on the finite interval. Assume that the solution existes, we show that this solution can be expressed in terms of the solution of a ... More
Numerical study of parametric pumping current in mesoscopic systems in the presence of magnetic fieldJan 06 2017We numerically study the parametric pumped current when magnetic field is applied both in the adiabatic and non-adiabatic regimes. In particular, we investigate the nature of pumped current for systems with resonance as well as anti-resonance. It is found ... More
Waiting Time Distribution of Quantum Electronic Transport in Transient RegimeMar 06 2014May 20 2014Waiting time is an important transport quantity that is complementary to average current and its fluctuation. So far all the studies of waiting time distribution (WTD) are limited to steady state transport (either dc or ac). In this work, we present a ... More
Projected Wirtinger Gradient Descent for Low-Rank Hankel Matrix Completion in Spectral Compressed SensingJul 14 2015This paper considers reconstructing a spectrally sparse signal from a small number of randomly observed time-domain samples. The signal of interest is a linear combination of complex sinusoids at $R$ distinct frequencies. The frequencies can assume any ... More
A model for continuous thermal Metal to Insulator TransitionMar 22 2017We propose a $d-$dimensional interacting Majorana fermion model with quenched disorder, which gives us a continuous quantum phase transition between a diffusive thermal metal phase with a finite entropy density to an insulator phase with zero entropy ... More
A PTAS for a Class of Stochastic Dynamic ProgramsMay 20 2018We develop a framework for obtaining polynomial time approximation schemes (PTAS) for a class of stochastic dynamic programs. Using our framework, we obtain the first PTAS for the following stochastic combinatorial optimization problems: \probemax: We ... More
Holographic fermionic spectrum with Weyl correctionFeb 25 2018We study the ferminoic spectrum with Weyl correction, which exhibits the non-Fermi liquid behavior. Also, we find that both the height of the peak of the fermionic spectrum and the dispersion relation exhibit a nonlinearity with the variety of the Weyl ... More
HyperAdam: A Learnable Task-Adaptive Adam for Network TrainingNov 22 2018Deep neural networks are traditionally trained using human-designed stochastic optimization algorithms, such as SGD and Adam. Recently, the approach of learning to optimize network parameters has emerged as a promising research topic. However, these learned ... More
Large Scale 2D Spectral Compressed Sensing in Continuous DomainMar 02 2019We consider the problem of spectral compressed sensing in continuous domain, which aims to recover a 2-dimensional spectrally sparse signal from partially observed time samples. The signal is assumed to be a superposition of s complex sinusoids. We propose ... More
Deep Learning-Based Least Square Forward-Backward Stochastic Differential Equation Solver for High-Dimensional Derivative PricingJul 24 2019We propose a new forward-backward stochastic differential equation solver for high-dimensional derivatives pricing problems by combining deep learning solver with least square regression technique widely used in the least square Monte Carlo method for ... More
Role of defects and geometry in the strength of polycrystalline grapheneFeb 05 2014Defects in solid commonly limit mechanical performance of the material. However, recent measurements reported that the extraordinarily high strength of graphene is almost retained with the presence of grain boundaries. We clarify in this work that lattice ... More
Learning and approximation capability of orthogonal super greedy algorithmSep 18 2014We consider the approximation capability of orthogonal super greedy algorithms (OSGA) and its applications in supervised learning. OSGA is concerned with selecting more than one atoms in each iteration step, which, of course, greatly reduces the computational ... More
Low Power SI Class E Power Amplifier and RF Switch For Health CareJan 06 2017This research was to design a 2.4 GHz class E Power Amplifier (PA) for health care, with 0.18um Semiconductor Manufacturing International Corporation CMOS technology by using Cadence software. And also RF switch was designed at cadence software with power ... More
Speeding Up Latent Variable Gaussian Graphical Model Estimation via Nonconvex OptimizationsFeb 28 2017We study the estimation of the latent variable Gaussian graphical model (LVGGM), where the precision matrix is the superposition of a sparse matrix and a low-rank matrix. In order to speed up the estimation of the sparse plus low-rank components, we propose ... More
Emittance fluctuation of mesoscopic conductors in the presence of disordersApr 16 2008We report the investigation of the dynamic conductance fluctuation of disordered mesoscopic conductors including 1D, 2D and quantum dot systems. Our numerical results show that in the quasi-ballistic regime the average emittance is negative indicating ... More
Automatic Detection of Significant Areas for Functional Data with Directional Error ControlApr 30 2015To detect differences between the mean curves of two samples in longitudinal study or functional data analysis, we usually need to partition the temporal or spatial domain into several pre-determined sub-areas. In this paper we apply the idea of large-scale ... More
Valley Seebeck effect in gate tunable zigzag graphene nanoribbonsJan 06 2017We propose, for the first time, a valley Seebeck effect in gate tunable zigzag graphene nanoribbons as a result of the interplay between thermal gradient and valleytronics. A pure valley current is further generated by the thermal gradient as well as ... More
Orbital Orders and non-Fermi Liquid in Moiré systemsSep 17 2019Motivated by recent experiments, we study three different orbital orders that potentially can happen in the Moir\'{e} systems: (1) the nematic order; (2) the valley polarization; and (3) the "compass order". Each order parameter spontaneously breaks part ... More
Interacting Valley Chern Insulator and its Topological Imprint on Moiré SuperconductorsJun 17 2019One salient feature of systems with Moir\'{e} superlattice is that, Chern number of "minibands" originating from each valley of the original graphene Brillouin zone becomes a well-defined quantized number because the miniband from each valley can be isolated ... More
Geographical effects on epidemic spreading in scale-free networksJun 30 2006Many real networks are embedded in a metric space: the interactions among individuals depend on their spatial distances and usually take place among their nearest neighbors. In this paper, we introduce a modified susceptible-infected-susceptible (SIS) ... More
Super Interaction Neural NetworkMay 29 2019Recent studies have demonstrated that the convolutional networks heavily rely on the quality and quantity of generated features. However, in lightweight networks, there are limited available feature information because these networks tend to be shallower ... More
A Calibration Method for Wide Field Multicolor Photometric SystemMar 04 1999Mar 07 1999The purpose of this paper is to present a method to self-calibrate the spectral energy distribution (SED) of objects in a survey based on the fitting of an SED library to the observed multi-color photometry. We adopt for illustrative purposes the Vilnius ... More
Representing Big Data as Networks: New Methods and InsightsDec 27 2017Our world produces massive data every day; they exist in diverse forms, from pairwise data and matrix to time series and trajectories. Meanwhile, we have access to the versatile toolkit of network analysis. Networks also have different forms; from simple ... More
Valley filtering effect of phonons in graphene with a grain boundaryFeb 20 2019Due to their possibility to encode information and realize low-energy-consumption quantum devices, control and manipulation of the valley degree of freedom have been widely studied in electronic systems. In contrast, the phononic counterpart--valley phononics--has ... More
Growing community networks with local eventsFeb 04 2009The study of community networks has attracted considerable attention recently. In this paper, we propose an evolving community network model based on local processes, the addition of new nodes intra-community and new links intra- or inter-community. Employing ... More
Reduced fidelity susceptibility and its finite-size scaling behaviorsMay 27 2008We derive a general formula of the reduced fidelity susceptibility when the reduced density matrix is $2\times2$ block-diagonal. By using this result and the continuous unitary transformations, we study finite-size scaling of the reduced fidelity susceptibility ... More
HoNVis: Visualizing and Exploring Higher-Order NetworksFeb 02 2017Unlike the conventional first-order network (FoN), the higher-order network (HoN) provides a more accurate description of transitions by creating additional nodes to encode higher-order dependencies. However, there exists no visualization and exploration ... More
Atomic Design of Three-Dimensional Photonic $Z_2$ Dirac and Weyl PointsJan 10 2016Jan 26 2016Topological nodal points such as Dirac and Weyl points in photonic spectrum, as monopoles of the synthetic gauge fields in ${\vec k}$-space, offer unique abilities of manipulating light. However, designing topological nodal points in photonic crystals ... More
Structural Diversity and Homophily: A Study Across More than One Hundred Large-Scale NetworksFeb 23 2016Understanding the ways in which local network structures are formed and organized is a fundamental problem in network science. A widely recognized organizing principle is structural homophily, which suggests that people with more common neighbors are ... More
Time-domain global similarity method for automatic data cleaning for multi-channel measurement systems in magnetic confinement fusion devicesMay 14 2017Sep 02 2017To guarantee the availability and reliability of data source in Magnetic Confinement Fusion (MCF) devices, incorrect diagnostic data, which cannot reflect real physical properties of measured objects, should be sorted out before further analysis and study. ... More
An unlikely resultJan 28 2005Oct 29 2005This paper has been withdrawn by the authors
Does the scale-free topology favor the emergence of cooperation?Aug 30 2005Sep 01 2005In a recent Letter [F.C. Santos and J. M. Pacheco Phys. Rev. Lett. \textbf{95}, 098104 (2005)], the scale-free networks are found to be advantageous for the emergence of cooperation. In the present work an evolutionary prisoner's dilemma game with players ... More
Interferometric detection of Chern numbers in topological optical latticesOct 16 2014Aug 13 2015Topological states of matter emergent as a new type of quantum phases, which can be distinguished by their associated topological invariants, e.g., Chern numbers. Currently, there is increasing in-terests toward the physically detection of the new predicted ... More
A survey of sparse representation: algorithms and applicationsFeb 23 2016Sparse representation has attracted much attention from researchers in fields of signal processing, image processing, computer vision and pattern recognition. Sparse representation also has a good reputation in both theoretical research and practical ... More
Microplasticity and yielding in crystals with heterogeneous dislocation distributionDec 29 2018In this study, we use discrete dislocation dynamics (DDD) simulation to investigate the effect of heterogeneous dislocation density on the transition between quasi-elastic deformation and plastic flow in face-centered cubic single crystals. By analyzing ... More
Unsupervised Part-based Weighting Aggregation of Deep Convolutional Features for Image RetrievalMay 03 2017Nov 29 2017In this paper, we propose a simple but effective semantic part-based weighting aggregation (PWA) for image retrieval. The proposed PWA utilizes the discriminative filters of deep convolutional layers as part detectors. Moreover, we propose the effective ... More
Design of Block Transceivers with Decision Feedback DetectionApr 05 2005This paper presents a method for jointly designing the transmitter-receiver pair in a block-by-block communication system that employs (intra-block) decision feedback detection. We provide closed-form expressions for transmitter-receiver pairs that simultaneously ... More
Detecting topological exceptional points in a parity-time symmetric system with cold atomsNov 08 2016We reveal a novel topological property of the exceptional points in a two-level parity-time symmetric system and then propose a scheme to detect the topological exceptional points in the system, which is embedded in a larger Hilbert space constructed ... More
On the sizes of $k$-edge-maximal $r$-uniform hypergraphsFeb 24 2018Jul 17 2018Let $H=(V,E)$ be a hypergraph, where $V$ is a set of vertices and $E$ is a set of non-empty subsets of $V$ called edges. If all edges of $H$ have the same cardinality $r$, then $H$ is a $r$-uniform hypergraph; if $E$ consists of all $r$-subsets of $V$, ... More
Nonseparating trees in 2-connected graphs and oriented trees in strongly connected digraphsOct 05 2017Oct 08 2017Mader [J. Graph Theory 65 (2010) 61-69] conjectured that for every positive integer $k$ and every finite tree $T$ with order $m$, every $k$-connected, finite graph $G$ with $\delta(G)\geq \lfloor\frac{3}{2}k\rfloor+m-1$ contains a subtree $T'$ isomorphic ... More
Learning to Explore with Meta-Policy GradientMar 13 2018Mar 26 2018The performance of off-policy learning, including deep Q-learning and deep deterministic policy gradient (DDPG), critically depends on the choice of the exploration policy. Existing exploration methods are mostly based on adding noise to the on-going ... More
Sliding Z Transform: Applications to convolutive blind source separationAug 08 2018The Z Transform is a mathematical operation in signal processing, which gives a tractable way to solve linear, constant-coefficient difference equations. Based on the classical Z transform and inspired by the thought of sliding DFT, a new definition of ... More
Theoretical study on nuclear structure by the multiple Coulomb scattering and magnetic scattering of relativistic electronsJan 26 2016Electron scattering is an effective method to study the nuclear structure. For the odd-$A$ nuclei with proton holes in the outmost orbits, we investigate the contributions of proton holes to the nuclear quadrupole moments $Q$ and magnetic moments $\mu$ ... More
Adversarial Soft-detection-based Aggregation Network for Image RetrievalNov 19 2018Mar 29 2019In recent year, the compact representations based on activations of Convolutional Neural Network (CNN) achieve remarkable performance in image retrieval. However, retrieval of some interested object that only takes up a small part of the whole image is ... More
Multi-hump solitary waves of nonlinear Dirac equationNov 29 2013This paper concentrates on a (1+1)-dimensional nonlinear Dirac (NLD) equation with a general self-interaction, being a linear combination of the scalar, pseudoscalar, vector and axial vector self-interactions to the power of the integer $k+1$. The solitary ... More
Interpretable Encrypted Searchable Neural NetworksAug 14 2019In cloud security, traditional searchable encryption (SE) requires high computation and communication overhead for dynamic search and update. The clever combination of machine learning (ML) and SE may be a new way to solve this problem. This paper proposes ... More
Learning rates of $l^q$ coefficient regularization learning with Gaussian kernelDec 19 2013Sep 25 2014Regularization is a well recognized powerful strategy to improve the performance of a learning machine and $l^q$ regularization schemes with $0<q<\infty$ are central in use. It is known that different $q$ leads to different properties of the deduced estimators, ... More
Latent Dirichlet Allocation in Generative Adversarial NetworksDec 17 2018Jul 16 2019We study the problem of multimodal generative modelling of images based on generative adversarial networks (GANs). Despite the success of existing methods, they often ignore the underlying structure of vision data or its multimodal generation characteristics. ... More
Exact Hybrid Covariance Thresholding for Joint Graphical LassoMar 07 2015Jun 18 2015This paper considers the problem of estimating multiple related Gaussian graphical models from a $p$-dimensional dataset consisting of different classes. Our work is based upon the formulation of this problem as group graphical lasso. This paper proposes ... More
Elastic higher-order topological insulators with quantization of the quadrupole momentsSep 09 2019Sep 11 2019We demonstrate that HOTIs with the quantization of the quadrupole moments can be realized in the two-dimensional elastic phononic crystals (PnCs). Both one-dimensional (1D) topological edge states and zero-dimensional (0D) topological corner states are ... More
Learning a Convolutional Neural Network for Non-uniform Motion Blur RemovalMar 02 2015Apr 12 2015In this paper, we address the problem of estimating and removing non-uniform motion blur from a single blurry image. We propose a deep learning approach to predicting the probabilistic distribution of motion blur at the patch level using a convolutional ... More
Order parameter analysis of synchronization transitions on star networksJan 10 2017Collective behaviors of populations of coupled oscillators have attracted much attention in recent years. In this paper, an order parameter approach is proposed to study the low-dimensional dynam- ical mechanism of collective synchronizations by adopting ... More
Order parameter analysis for low-dimensional behaviors of coupled phase-oscillatorsAug 01 2015Sep 16 2015Coupled phase-oscillators are important models related to synchronization. Recently, Ott-Antonsen(OA) ansatz is developed and used to get low-dimensional collective behaviors in coupled oscillator systems. In this paper, we develop a simple and concise ... More
ZBroker: A Query Routing Broker for Z39.50 DatabasesFeb 09 1999A query routing broker is a software agent that determines from a large set of accessing information sources the ones most relevant to a user's information need. As the number of information sources on the Internet increases dramatically, future users ... More
Deep Representation of Facial Geometric and Photometric Attributes for Automatic 3D Facial Expression RecognitionNov 10 2015In this paper, we present a novel approach to automatic 3D Facial Expression Recognition (FER) based on deep representation of facial 3D geometric and 2D photometric attributes. A 3D face is firstly represented by its geometric and photometric attributes, ... More
Robust Classification with Sparse Representation Fusion on Diverse Data SubsetsJun 10 2019Sparse Representation (SR) techniques encode the test samples into a sparse linear combination of all training samples and then classify the test samples into the class with the minimum residual. The classification of SR techniques depends on the representation ... More
Context-Dependent Diffusion Network for Visual Relationship DetectionSep 11 2018Visual relationship detection can bridge the gap between computer vision and natural language for scene understanding of images. Different from pure object recognition tasks, the relation triplets of subject-predicate-object lie on an extreme diversity ... More
Discriminative Block-Diagonal Representation Learning for Image RecognitionJul 12 2017Existing block-diagonal representation researches mainly focuses on casting block-diagonal regularization on training data, while only little attention is dedicated to concurrently learning both block-diagonal representations of training and test data. ... More
STA: Adversarial Attacks on Siamese TrackersSep 08 2019Recently, the majority of visual trackers adopt Convolutional Neural Network (CNN) as their backbone to achieve high tracking accuracy. However, less attention has been paid to the potential adversarial threats brought by CNN, including Siamese network. ... More
Hidden Hamiltonian Cycle Recovery via Linear ProgrammingApr 15 2018We introduce the problem of hidden Hamiltonian cycle recovery, where there is an unknown Hamiltonian cycle in an $n$-vertex complete graph that needs to be inferred from noisy edge measurements. The measurements are independent and distributed according ... More
Visual Saliency Based on Scale-Space Analysis in the Frequency DomainMay 06 2016We address the issue of visual saliency from three perspectives. First, we consider saliency detection as a frequency domain analysis problem. Second, we achieve this by employing the concept of {\it non-saliency}. Third, we simultaneously consider the ... More
Origin of Constrained Maximal CP Violation in Flavor SymmetryJul 13 2015Oct 27 2015Current data from neutrino oscillation experiments are in good agreement with $\delta =-\frac{\pi}{2}$ and $\theta_{23}^{} = \frac{\pi}{4}$. We define the notion of "constrained maximal CP violation" (CMCPV) for predicting these features and study their ... More
Gauge-Invariant Quantum Gravity Corrections to Gauge Couplings via Vilkovisky-DeWitt Method and Gravity Assisted Gauge UnificationAug 11 2010Nov 16 2010Gravity is the weakest force in nature, and the gravitational interactions with all standard model (SM) particles can be well described by perturbative expansions of the Einstein-Hilbert action as an effective theory, all the way up to energies below ... More
iTreePack: Protein Complex Side-Chain Packing by Dual DecompositionApr 21 2015Protein side-chain packing is a critical component in obtaining the 3D coordinates of a structure and drug discovery. Single-domain protein side-chain packing has been thoroughly studied. A major challenge in generalizing these methods to protein complexes ... More
Impacts of preference and geography on epidemic spreadingOct 21 2007We investigate the standard susceptible-infected-susceptible model on a random network to study the effects of preference and geography on diseases spreading. The network grows by introducing one random node with $m$ links on a Euclidean space at unit ... More
Unsupervised Semantic-based Aggregation of Deep Convolutional FeaturesApr 03 2018In this paper, we propose a simple but effective semantic-based aggregation (SBA) method. The proposed SBA utilizes the discriminative filters of deep convolutional layers as semantic detectors. Moreover, we propose the effective unsupervised strategy ... More
Accurate space potential measurements with emissive probe in high pressure plasma and neutral gasJun 03 2019The accurate measurement of plasma potentials at high pressure is investigated with the emissive probe. The emissive probe I-V characteristic of argon plasma obtained at 100 Pa is interpreted in detail, showing two inflection points in the I-V trace. ... More
Demonstration of active feedforward one-way quantum computing with photon-matter hyperentanglementDec 08 2012We report an optical one-way quantum computing experiment with stationary quantum memory involved. First we create a hybrid four-qubit cluster state with two qubits propagating as photons and the other two stationary and stored in a laser-cooled atomic-ensemble ... More
Excitable Greenberg-Hastings cellular automaton model on scale-free networksJan 11 2007We study the excitable Greenberg-Hastings cellular automaton model on scale-free networks. We obtained analytical expressions for no external stimulus and the uncoupled case. It is found that the curves, the average activity $F$ versus the external stimulus ... More
$\left( β, \varpi \right)$-stability for cross-validation and the choice of the number of foldsMay 20 2017Jul 06 2017In this paper, we introduce a new concept of stability for cross-validation, called the $\left( \beta, \varpi \right)$-stability, and use it as a new perspective to build the general theory for cross-validation. The $\left( \beta, \varpi \right)$-stability ... More
An efficient numerical method for a time-fractional diffusion equationOct 18 2018A reaction-diffusion problem with a Caputo time derivative is considered. An integral discretization scheme on a graded mesh along with a decomposition of the exact solution is proposed. The truncation error estimate of the discretization scheme is derived ... More
Collective dynamics of identical phase oscillators with high-order couplingApr 17 2016In this paper, we propose a framework to investigate the collective dynamics in ensembles of globally coupled phase oscillators when higher-order modes dominate the coupling. The spatiotemporal properties of the attractors in various regions of parameter ... More
Extrinsic photonic crystalsDec 12 2005Doped semiconductors are intrinsically homogeneous media. However, by applying an external magnetic field that has a spatially periodic variation, doped semiconductors can behave extrinsically like conventional photonic crystals. We show this possibility ... More
OpenMPR: Recognize Places Using Multimodal Data for People with Visual ImpairmentsSep 15 2019Place recognition plays a crucial role in navigational assistance, and is also a challenging issue of assistive technology. The place recognition is prone to erroneous localization owing to various changes between database and query images. Aiming at ... More
Does generalization performance of $l^q$ regularization learning depend on $q$? A negative exampleJul 25 2013$l^q$-regularization has been demonstrated to be an attractive technique in machine learning and statistical modeling. It attempts to improve the generalization (prediction) capability of a machine (model) through appropriately shrinking its coefficients. ... More
Transmission resonances for a Dirac particle in a one-dimensional Hulthén potentialOct 13 2007We have solved exactly the two-component Dirac equation in the presence of a spatially one-dimensional Hulth\'en potential, and presented the Dirac spinors of scattering states in terms of hypergeometric functions. We have calculated the reflection and ... More
Learning Latent Features with Pairwise Penalties in Matrix CompletionFeb 16 2018Low-rank matrix completion (MC) has achieved great success in many real-world data applications. A latent feature model formulation is usually employed and, to improve prediction performance, the similarities between latent variables can be exploited ... More
Maximal monotone operator theory and its applications to thin film equation in epitaxial growth on vicinal surfaceMay 19 2017Mar 14 2018In this work we consider $$ w_t=[(w_{hh}+c_0)^{-3}]_{hh},\qquad w(0)=w^0, $$ which is derived from a thin film equation for epitaxial growth on vicinal surface. We formulate the problem as the gradient flow of a suitably-defined convex functional in a ... More
Helicity hardens the gasJan 02 2019A screw generally works better than a nail, or a complicated rope knot better than a simple one, in fastening solid matter, but a gas is more tameless. However, a flow itself has a physical quantity, helicity, measuring the screwing strength of the velocity ... More
Temporal prediction of epidemic patterns in community networksNov 17 2013Most previous studies of epidemic dynamics on complex networks suppose that the disease will eventually stabilize at either a disease-free state or an endemic one. In reality, however, some epidemics always exhibit sporadic and recurrent behaviour in ... More
Block Iterative Reweighted Algorithms for Super-Resolution of Spectrally Sparse SignalsJul 30 2015Sep 11 2015We propose novel algorithms that enhance the performance of recovering unknown continuous-valued frequencies from undersampled signals. Our iterative reweighted frequency recovery algorithms employ the support knowledge gained from earlier steps of our ... More
SRLA: A real time sliding time window super point cardinality estimation algorithm for high speed network based on GPUMar 28 2018Jul 04 2018Super point is a special host in network which communicates with lots of other hosts in a certain time period. The number of hosts contacting with a super point is called as its cardinality. Cardinality estimating plays important roles in network management ... More
Biased random walk conditioned on survival among Bernoulli obstacles: subcritical phaseApr 16 2019We consider a discrete time biased random walk conditioned to avoid Bernoulli obstacles on ${\mathbb Z}^d$ ($d\geq 2$) up to time $N$. This model is known to undergo a phase transition: for a large bias, the walk is ballistic whereas for a small bias, ... More
Joint & Progressive Learning from High-Dimensional Data for Multi-Label ClassificationAug 15 2018Despite the fact that nonlinear subspace learning techniques (e.g. manifold learning) have successfully applied to data representation, there is still room for improvement in explainability (explicit mapping), generalization (out-of-samples), and cost-effectiveness ... More