Results for "T. Qian"

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Probing the excited-state quantum phase transition through statistics of Loschmidt echo and quantum workMay 12 2017Sep 28 2017By analyzing the probability distributions of the Loschmidt echo (LE) and quantum work, we examine the nonequilibrium effects of a quantum many-body system, which exhibits an excited-state quantum phase transition (ESQPT). We find that depending on the ... More
Understanding quantum work in a quantum many-body systemDec 17 2016Mar 10 2017Based on previous studies in a single particle system in both the integrable [Jarzynski, Quan, and Rahav, Phys.~Rev.~X {\bf 5}, 031038 (2015)] and the chaotic systems [Zhu, Gong, Wu, and Quan, Phys.~Rev.~E {\bf 93}, 062108 (2016)], we study the the correspondence ... More
Universal Order Parameters and Quantum Phase Transitions: A Finite-Size ApproachJun 13 2014We propose a method to construct universal order parameters for quantum phase transitions in many-body lattice systems. The method exploits the $H$-orthogonality of a few near-degenerate lowest states of the Hamiltonian describing a given finite-size ... More
Anomalous Hall effect in ferromagnetic semiconductorsOct 22 2001We present a theory of the anomalous Hall effect in ferromagnetic (Mn,III)V semiconductors. Our theory relates the anomalous Hall conductance of a homogeneous ferromagnet to the Berry phase acquired by a quasiparticle wavefunction upon traversing closed ... More
ARPES measurements of the superconducting gap of Fe-based superconductors and their implications to the pairing mechanismMar 25 2015Jul 09 2015Its direct momentum sensitivity confers to angle-resolved photoemission spectroscopy (ARPES) a unique perspective in investigating the superconducting gap of multi-band systems. In this review we discuss ARPES studies on the superconducting gap of the ... More
Effects of the Dzyaloshinsky-Moriya interaction on nonequilibrium thermodynamics in the $XY$ chain in a transverse fieldMay 08 2018Aug 09 2018We examine the effects of the Dzyaloshinsky-Moriya (DM) interaction on the nonequilibrium thermodynamics in an anisotropic $XY$ spin chain, which is driven out of equilibrium by a sudden quench of the control parameter of the Hamiltonian. By analytically ... More
A Functional Approach to FBSDEs and Its Application in Optimal PortfoliosNov 19 2010In Liang et al (2009), the current authors demonstrated that BSDEs can be reformulated as functional differential equations, and as an application, they solved BSDEs on general filtered probability spaces. In this paper the authors continue the study ... More
Groundstate fidelity phase diagram of the fully anisotropic two-leg spin-1/2 XXZ ladderApr 18 2017Aug 28 2017The fully anisotropic two-leg spin-1/2 $XXZ$ ladder model is studied in terms of an algorithm based on the tensor network representation of quantum many-body states as an adaptation of projected entangled pair states to the geometry of translationally ... More
Packing Sparse Convolutional Neural Networks for Efficient Systolic Array Implementations: Column Combining Under Joint OptimizationNov 07 2018This paper describes a novel approach of packing sparse convolutional neural networks for their efficient systolic array implementations. By combining subsets of columns in the original filter matrix associated with a convolutional layer, we increase ... More
InferBeam: A Fast Beam Alignment Protocol for Millimeter-wave NetworkingFeb 09 2018Mar 05 2018We introduce fast millimeter-wave base station (BS) and its antenna sector selection for user equipment based on its location. Using a conditional random field inference model with specially designed parameters, which are robust to change of environment, ... More
Adaptive orthonormal systems for matrix-valued functionsNov 24 2015In this paper we consider functions in the Hardy space $\mathbf{H}_2^{p\times q}$ defined in the unit disc of matrix-valued. We show that it is possible, as in the scalar case, to decompose those functions as linear combinations of suitably modified matrix-valued ... More
Coupling of electronic and magnetic properties in Fe1+y(Te1-xSex)Nov 03 2011Aug 28 2013We have studied the coupling of electronic and magnetic properties in Fe1+y(Te1-xSex) via systematic specific heat, magnetoresistivity, and Hall coefficient measurements on two groups of samples with y = 0.02 and 0.1. In the y = 0.02 series, we find that ... More
The $H^\infty$ functional calculus based on the $S$-spectrum for quaternionic operators and for $n$-tuples of noncommuting operatorsNov 24 2015In this paper we extend the $H^\infty$ functional calculus to quaternionic operators and to $n$-tuples of noncommuting operators using the theory of slice hyperholomorphic functions and the associated functional calculus, called $S$-functional calculus. ... More
A ray-based IPDG method for high-frequency time-domain acoustic wave propagation in inhomogeneous mediaApr 23 2017The numerical approximation of high-frequency wave propagation in inhomogeneous media is a challenging problem. In particular, computing high-frequency solutions by direct simulations requires several points per wavelength for stability and usually requires ... More
Full-stack Optimization for Accelerating CNNs with FPGA ValidationMay 01 2019We present a full-stack optimization framework for accelerating inference of CNNs (Convolutional Neural Networks) and validate the approach with field-programmable gate arrays (FPGA) implementations. By jointly optimizing CNN models, computing architectures, ... More
Cyclic period oscillation of the eclipsing dwarf nova DV UMaMay 09 2017DV UMa is an eclipsing dwarf nova with an orbital period of $\sim2.06$ h, which lies just at the bottom edge of the period gap. To detect its orbital period changes we present 12 new mid-eclipse times by using our CCD photometric data and archival data. ... More
Axisymmetric galaxy models wth central BHs, with an application to M32Dec 19 1994The contour integral method of Hunter & Qian is applied to axisymmetric galaxy models in which the distribution function (DF) is of the form f=f(E,L_z), where E and L_z are the classical integrals of motion in an axisymmetric potential. A practical way ... More
Attentive Generative Adversarial Network for Raindrop Removal from a Single ImageNov 28 2017May 06 2018Raindrops adhered to a glass window or camera lens can severely hamper the visibility of a background scene and degrade an image considerably. In this paper, we address the problem by visually removing raindrops, and thus transforming a raindrop degraded ... More
Importance of Granular Structure in the Initial Conditions for the Elliptic FlowApr 30 2008We show effects of granular structure of the initial conditions (IC) of hydrodynamic description of high-energy nucleus-nucleus collisions on some observables, especially on the elliptic-flow parameter v2. Such a structure enhances production of isotropically ... More
New Photometric Investigation of the Low-Mass-Ratio Contact Binary Star V1853 OrionisNov 05 2018Four-color charge-coupled device (CCD) light curves in $B$, $V$, $Rc$ and $Ic$ bands of the total-eclipsing binary system, V1853 Ori, are presented. By comparing our light curves with those published by previous investigators, it is detected that the ... More
A Threshold-free Prospective Prediction Accuracy Measure for Censored Time to Event DataJun 13 2016Sep 14 2016Prediction performance of a risk scoring system needs to be carefully assessed before its adoption in clinical practice. Clinical preventive care often uses risk scores to screen asymptomatic population. The primary clinical interest is to predict the ... More
WZ Sge: an eclipsing cataclysmic variable evolving towards the period minimumMay 09 2017We present the photometric results of the eclipsing cataclysmic variable (CV) WZ Sge near the period minimum ($P_{min}$). Eight new mid-eclipse times were determined and the orbital ephemeris was updated. Our result shows that the orbital period of WZ ... More
Gutzwiller density functional calculations of the electronic structure of FeAs-based superconductors: Evidence for a three-dimensional Fermi surfaceMar 08 2009May 19 2009The electronic structures of FeAs-compounds strongly depend on the Fe-As bonding, which can not be described successfully by the local density approximation (LDA). Treating the multi-orbital fluctuations from $ab$-$initio$ by LDA+Gutzwiller method, we ... More
Calorimetric Evidence of Strong-Coupling Multiband Superconductivity in Fe(Te0.57Se0.43) Single CrystalMar 15 2011We have investigated the specific heat of optimally-doped iron chalcogenide superconductor Fe(Te0.57Se0.43) with a high-quality single crystal sample. The electronic specific heat Ce of this sample has been successfully separated from the phonon contribution ... More
Dissipative Stability Conditions for Linear Coupled Differential-Difference Systems via a Dynamical Constraints ApproachJul 07 2017Oct 26 2017In this short note, we derive dissipative conditions with slack variables for a linear coupled differential-difference (CDDS) via constructing a Krasovskii functional. The approach can be interpreted as a generalization of the Finsler Lemma approach for ... More
Fisher information matrix for three-parameter exponentiated-Weibull distribution under type II censoringFeb 01 2011This paper considers the three-parameter exponentiated Weibull family under type II censoring. It first graphically illustrates the shape property of the hazard function. Then, it proposes a simple algorithm for computing the maximum likelihood estimator ... More
An intrinsic hyperboloid approach for Einstein Klein-Gordon equationsJul 06 2016In [7] Klainerman introduced the hyperboloidal method to prove the global existence results for nonlinear Klein-Gordon equations by using commuting vector fields. In this paper, we extend the hyperboloidal method from Minkowski space to Lorentzian spacetimes. ... More
Resonance-enhanced collective effect in a triangle arrangement of Rydberg atoms with anisotropic interactionsJul 08 2016We investigate the collective excitation effect in a scheme where three identical Rydberg atoms are arranged in an equilateral triangular lattice. By using a static electric field polarizing the atomic dipoles, the dipole-dipole interactions between two ... More
Asymptotic estimates on the time derivative of $Φ$-entropy on Riemannian manifoldsApr 16 2011Aug 11 2011In this note, we obtain the asymptotic estimate for the time derivative of the $\Phi$-entropy in terms of the lower bound on the Bakry-Emery $\Gamma_2$ curvature. In the cases of Hyperbolic space and Heisenberg group, we show that the time derivative ... More
Backward doubly stochastic differential equations with weak assumptions on the coefficientsMay 28 2010Apr 07 2011In this paper, we deal with one dimensional backward doubly stochastic differential equations (BDSDEs) where the coefficient is left Lipschitz in y (may be discontinuous) and uniformly continuous in z. We obtain a generalized comparison theorem and a ... More
Model simulation of optical light curves for blazar OJ287Apr 06 2019The light curves of optical outbursts observed in blazar OJ287 during 1983-2015 are analyzed and model-simulated to investigate the nature of its optical radiation. It is shown that the December/2015 outburst has its multi-wavelength variability behavior ... More
Two-Dimensional Adaptive Fourier DecompositionJun 09 2014Mar 18 2015One-dimensional adaptive Fourier decomposition, abbreviated as 1-D AFD, or AFD, is an adaptive representation of a physically realizable signal into a linear combination of parameterized Szeg\"o and higher order Szeg\"o kernels of the context. In the ... More
A Novel Fourier Theory on Non-linear Phases and ApplicationsMay 16 2018Positive time varying frequency representation for transient signals has been a hearty desire of signal analysts due to its theoretical and practical importance. During approximately the last two decades there has formulated a signal decomposition and ... More
The Analysis to Quasi-Local Energy and Hamiltonian Constraint based on VariationNov 07 2013Nov 14 2013In this paper, by arising condition in variation, from equal time to non-equal time, I reconsider how geometrodynamics equations allow to be derived from variational principle in general relativity and then find the variation of extrinsic curvature dependent ... More
Hyperbolic Metric, Punctured Riemann Sphere and Modular FunctionsJan 21 2019We derive a precise asymptotic expansion of the complete K\"{a}hler-Einstein metric on the punctured Riemann sphere with three or more omitting points. By using Schwarzian derivative, we prove that the coefficients of the expansion are polynomials on ... More
Flow polynomials of a signed graphMay 21 2018Jun 25 2018In contrast to ordinary graphs, the number of the nowhere-zero group-flows in a signed graph may vary with different groups, even if the groups have the same order. In fact, for a signed graph $G$ and non-negative integer $d$, it was shown that there ... More
Multi-stage Clustering of Breast Cancer for Precision MedicineDec 02 2016Cancer has become one of the most widespread diseases in the world. Specifically, breast cancer is diagnosed more often than any other type of cancer. However, breast cancer patients and their individual tumors are often unique. Identifying the underlying ... More
Asymptotic behavior of the Kohn-Sham exchange potential at a metal surfaceJun 25 2015The asymptotic structure of the Kohn-Sham exchange potential $v_x ({\bf r})$ in the classically forbidden region of a metal surface is investigated, together with that of the Slater exchange potential $V_x^S ({\bf r})$ and those of the approximate Krieger-Li-Iafrate ... More
The on-top pair-correlation density in the homogeneous electron liquidSep 07 2005The ladder theory, in which the Bethe-Goldstone equation for the effective potential between two scattering particles plays a central role, is well known for its satisfactory description of the short-range correlations in the homogeneous electron liquid. ... More
Long wavelength behavior of the dynamical spin-resolved local-field factor in a two-dimensional electron liquidApr 14 2004The high frequency limits of the singular component $A(\omega)$ of the small wavevector expansion of the longitudinal (L) and transverse (T) components of the spin-resolved exchange-correlation kernel tensor $f_{xc,\sigma \sigma'}^{L,T}(q,\omega)=-v(q)G_{\sigma ... More
Bounds for the second and the third derivatives of the electron density at the nucleusSep 27 2007Jan 02 2008Lower bound for ${\bar \rho}''(0)$, the second derivative of the spherically averaged atomic electronic density at the nucleus, and upper bound for ${\bar \rho}'''(0)$, the third derivative, are obtained respectively. It is shown that, for the ground ... More
A BSDE approach to Nash equilibrium payoffs for stochastic differential games with nonlinear cost functionalsJun 06 2011Aug 23 2011In this paper, we study Nash equilibrium payoffs for nonzero-sum stochastic differential games via the theory of backward stochastic differential equations. We obtain an existence theorem and a characterization theorem of Nash equilibrium payoffs for ... More
Nash equilibrium payoffs for stochastic differential games with reflectionOct 18 2011Mar 21 2013In this paper, we investigate Nash equilibrium payoffs for nonzero-sum stochastic differential games with reflection. We obtain an existence theorem and a characterization theorem of Nash equilibrium payoffs for nonzero-sum stochastic differential games ... More
Local time and Tanaka formula for G-Brownian MotionDec 08 2009Oct 20 2012In this paper, we study the notion of local time and Tanaka formula for the G-Brownian motion. Moreover, the joint continuity of the local time of the G-Brownian motion is obtained and its quadratic variation is proven. As an application, we generalize ... More
Local Linear Constraint based Optimization Model for Dual Spectral CTJan 16 2017Dual spectral computed tomography (DSCT) can achieve energy- and material-selective images, and has a superior distinguishability of some materials than conventional single spectral computed tomography (SSCT). However, the decomposition process is illposed, ... More
Positive curvature property for sub-Laplace on nilpotent Lie group of rank twoDec 15 2011In this note, we concentrate on the sub-Laplace on the nilpotent Lie group of rank two, which is the infinitesimal generator of the diffusion generated by $n$ Brownian motions and their $\frac{n(n-1)}2$ L\'evy area processes, which is the simple extension ... More
Robust quantum switch with Rydberg excitationsSep 13 2017We develop an approach to realize a quantum switch for Rydberg excitation in atoms with $Y$-typed level configuration. We find that the steady population on two different Rydberg states can be reversibly exchanged in a controllable way by properly tuning ... More
New New-Phenomena Results from DzeroJun 10 1998We have searched for diphoton events (\ggmet) with large missing transverse momentum, $\gamma\rlap{\kern0.25em/}E_T$ events (\gmetjj) with two or more jets, and diphoton events ($\gamma\gamma$) with high transverse energies in $p\bar p$ collisions at ... More
Universality of superconducting gaps in overdoped Ba0.3K0.7Fe2As2 observed by angle-resolved photoemission spectroscopySep 22 2010Jan 13 2011We have performed angle-resolved photoemission spectroscopy on the overdoped Ba$_{0.3}$K$_{0.7}$Fe$_2$As$_2$ superconductor ($T_c$ = 22 K). We demonstrate that the superconducting (SC) gap on each Fermi surface (FS) is nearly isotropic whereas the gap ... More
Search for $J^{PC}=1^{-+}$ exotic state in $e^+e^-$ annihilationMar 10 2014The charmed meson pair $(\frac{3}{2})^+$ and anti-$(\frac{1}{2})^-$, i.e. $D_1(2420)\bar D+c.c.$, $D_1(2420)\bar D^*+c.c.$, $D_2(2460)\bar D^*+c.c.$, can couple to states with vector quantum number $J^{PC}=1^{--}$ and exotic quantum number $J^{PC}=1^{-+}$ ... More
Differential Harnack inequalities and Perelman type entropy formulae for subelliptic operatorsJul 09 2013In this paper, under the generalized curvature-dimension inequality recently introduced by F. Baudoin and N. Garofalo, we obtain differential Harnack inequalities for the positive solutions to the Sch\"odinger equation associated to subelliptic operator ... More
A geometric perspective on the method of descentMar 19 2017We derive a representation formula for the tensorial wave equation $\Box_\bg \phi^I=F^I$ in globally hyperbolic Lorentzian spacetimes $(\M^{2+1}, \bg)$ by giving a geometric formulation of the method of descent which is applicable for any dimension.
On the exterior stability of nonlinear wave equationsAug 07 2018We consider a very general class of nonlinear wave equations, which admit trivial solutions and not necessarily verify any form of null conditions. For compactly supported small data, one can only have a semi-global result which states that the solutions ... More
Sensitivity to Gauge-Mediated Supersymmetry Breaking Models of the Fermilab Upgraded Tevatron ColliderMar 31 1999Oct 14 1999This paper discusses supersymmetry discovery potential of the upgraded D\O experiment at the Tevatron $p\bar{p}$ collider. Six final states with large transverse energy (momentum) leptons or photons (with or without large transverse momentum imbalances) ... More
Finding the Optimal Demodulator Under Implementation ConstraintsJun 03 2015Mar 23 2016The common approach of designing a communication device is to maximize a well-defined objective function, e.g., the channel capacity and the cut-off rate. We propose easy-to-implement solutions for Gaussian channels that approximate the optimal results ... More
Nash equilibrium payoffs for stochastic differential games with jumps and coupled nonlinear cost functionalsAug 18 2011Jul 18 2013In this paper we investigate Nash equilibrium payoffs for two-player nonzero-sum stochastic differential games whose cost functionals are defined by a system of coupled backward stochastic differential equations. We obtain an existence theorem and a characterization ... More
Remarks on Li-Yau inequality on graphsNov 14 2013In this paper, we study Li-Yau gradient estimates for the solutions $u$ to the heat equation $\partial_tu=\Delta u$ on graphs under the curvature condition $CD(n,-K)$ introduced by Bauer et al. in \cite{BHLLMY}. As applications, we derive Harnack inequalities ... More
New phase transition in Na$_{2}$Ti$_{2}$As$_{2}$O revealed by Raman scatteringJan 08 2016We performed a Raman scattering study of Na$_2$Ti$_2$As$_2$O. We identified a symmetry breaking structural transition at around $T_s = 150$ K, which matches a large bump in the electrical resistivity. Several new peaks are detected below that transition. ... More
LAMOST Views $δ$ Scuti Pulsating StarsJul 13 2017Dec 27 2017About 766 $\delta$ Scuti stars were observed by LAMOST by June 16, 2017. Stellar atmospheric parameters of 525 variables were determined, while spectral types were obtained for all samples. In the paper, those spectroscopic data are catalogued. We detect ... More
Topology studies of hydrodynamics using two particle correlation analysisFeb 27 2009Dec 21 2009The effects of fluctuating initial conditions are studied in the context of relativistic heavy ion collisions where a rapidly evolving system is formed. Two particle correlation analysis is applied to events generated with the NEXSPHERIO hydrodynamic ... More
Corrections for the Geometric Distortion of the Tube Detectors on SANS Instruments at ORNLMay 08 2014The small-angle neutron scattering instruments at the Oak Ridge National Laboratory High Flux Isotope Reactor recently upgraded the area detectors from the large, single volume crossed-wire detectors originally installed to staggered arrays of linear ... More
Physics at Future Hadron CollidersJan 23 2002We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron ... More
The 1999aa-like Type Ia Supernova iPTF14bdn in the Ultraviolet and OpticalSep 23 2015We present ultraviolet (UV) and optical photometry and spectra of the 1999aa-like supernova (SN) iPTF14bdn. The UV data were observed using the Swift Ultraviolet/Optical Telescope (UVOT) and constitute the first UV spectral series of a 1999aa-like SN. ... More
DC-transport properties of ferromagnetic (Ga,Mn)As semiconductorsFeb 03 2003We study the dc transport properties of (Ga,Mn)As diluted magnetic semiconductors with Mn concentration varying from 1.5% to 8%. Both diagonal and Hall components of the conductivity tensor are strongly sensitive to the magnetic state of these semiconductors. ... More
Observation of strong electron pairing on bands without Fermi surfaces in LiFe1-xCoxAsJun 04 2014Jun 05 2014In conventional BCS superconductors, the quantum condensation of superconducting electron pairs is understood as a Fermi surface (FS) instability, in which the low-energy electrons are paired by attractive interactions. Whether this explanation is still ... More
Circular Stochastic Fluctuations in SIS Epidemics with Heterogeneous Contacts Among Sub-populationsDec 20 2011The conceptual difference between equilibrium and non-equilibrium steady state (NESS) is well established in physics and chemistry. This distinction, however, is not widely appreciated in dynamical descriptions of biological populations in terms of differential ... More
Synchronized Dynamics and Nonequilibrium Steady States in a Stochastic Yeast Cell-Cycle NetworkApr 15 2009Applying the mathematical circulation theory of Markov chains, we investigate the synchronized stochastic dynamics of a discrete network model of yeast cell-cycle regulation where stochasticity has been kept rather than being averaged out. By comparing ... More
Statistical Thermodynamics of General Minimal Diffusion Processes: Constuction, Invariant Density, Reversibility and Entropy ProductionJan 01 2002The solution to nonlinear Fokker-Planck equation is constructed in terms of the minimal Markov semigroup generated by the equation. The semigroup is obtained by a purely functional analytical method via Hille-Yosida theorem. The existence of the positive ... More
Jet launching in resistive GR-MHD black hole - accretion disk systemsApr 25 2018We investigate the launching mechanism of relativistic jets from black hole sources, in particular the strong winds from the surrounding accretion disk. Numerical investigations of the disk wind launching - the simulation of the accretion-ejection transition ... More
Stochastic Dynamics of Electrical Membrane with Voltage-Dependent Ion Channel FluctuationsApr 06 2014Brownian ratchet like stochastic theory for the electrochemical membrane system of Hodgkin-Huxley (HH) is developed. The system is characterized by a continuous variable $Q_m(t)$, representing mobile membrane charge density, and a discrete variable $K_t$ ... More
Convergences of Random Variables under Sublinear ExpectationsJul 26 2016Apr 27 2017In this note, we will survey the existing convergence results for random variables under sublinear expectations, and prove some new results. Concretely, under the assumption that the sublinear expectation has the monotone continuity property, we will ... More
A Note on Uniform Integrability of Random Variables in a Probability Space and Sublinear Expectation SpaceMay 23 2017Sep 22 2017In this note we discuss uniform integrability of random variables. In a probability space, we introduce two new notions on uniform integrability of random variables, and prove that they are equivalent to the classic one. In a sublinear expectation space, ... More
Fermi surface dichotomy of the superconducting gap and pseudogap in underdoped pnictidesMay 27 2009Jul 12 2011High-temperature superconductivity in iron-arsenic materials (pnictides) near an antiferromagnetic phase raises the possibility of spin-fluctuation-mediated pairing. However, the interplay between antiferromagnetic fluctuations and superconductivity remains ... More
Geometric optics of Bloch waves in a chiral and dissipative mediumApr 13 2009Apr 01 2010We present a geometric optics theory for the transport of quantum particles (or classical waves) in a chiral and dissipative periodic crystal subject to slowly varying perturbations in space and time. Taking account of some properties of particles and ... More
Geometrodynamics of electrons in a crystal under position and time dependent deformationFeb 06 2018Semiclassical dynamics of Bloch electrons in a crystal under slowly varying deformation is developed in the geometric language of a lattice bundle. Berry curvatures and gradients of energy are introduced in terms of lattice covariant derivatives, with ... More
On the number of hyperelliptic limit cycles of Liénard systemsOct 13 2017Apr 09 2018In this paper, we study the maximum number, denoted by $H(m,n)$, of hyperelliptic limit cycles of the Li\'enard systems $$\dot x=y, \qquad \dot y=-f_m(x)y-g_n(x),$$ where, respectively, $f_m(x)$ and $g_n(x)$ are real polynomials of degree $m$ and $n$, ... More
A Deep X-Ray Look At Abell 2142 --- Viscosity Constraints From Kelvin-Helmholtz Eddies, A Displaced Cool Peak That Makes A Warm Core, And A Possible Plasma Depletion LayerOct 05 2018We analyzed 200 ks of Chandra ACIS observations of the merging galaxy cluster A2142 to examine its prominent cold fronts in detail. We find that the southern cold front exhibits well-developed Kelvin-Helmholtz (KH) eddies seen in the sky plane. Comparing ... More
Robust Dropping Criteria for F-norm Minimization Based Sparse Approximate Inverse PreconditioningMar 11 2012Mar 16 2015Dropping tolerance criteria play a central role in Sparse Approximate Inverse preconditioning. Such criteria have received, however, little attention and have been treated heuristically in the following manner: If the size of an entry is below some empirically ... More
Topical differences between Chinese language Twitter and Sina WeiboDec 22 2015Sina Weibo, China's most popular microblogging platform, is currently used by over $500M$ users and is considered to be a proxy of Chinese social life. In this study, we contrast the discussions occurring on Sina Weibo and on Chinese language Twitter ... More
On Contraction of Algebraic PointsJul 06 2016Mar 08 2017We study contraction of points on $\mathbb{P}^1(\bar{\mathbb{Q}})$ with certain control on local ramification indices, with application to the unramified curve correspondences problem initiated by Bogomolov and Tschinkel.
The Sampling-and-Learning Framework: A Statistical View of Evolutionary AlgorithmsJan 24 2014Apr 11 2014Evolutionary algorithms (EAs), a large class of general purpose optimization algorithms inspired from the natural phenomena, are widely used in various industrial optimizations and often show excellent performance. This paper presents an attempt towards ... More
Response of gadolinium doped liquid scintillator to charged particles: measurement based on intrinsic U/Th contaminationJan 11 2018Mar 06 2018A measurement is reported for the response to charged particles of a liquid scintillator named EJ-335 doped with 0.5% gadolinium by weight. This liquid scintillator was used as the detection medium in a neutron detector. The measurement is based on the ... More
Physical Properties and Evolutionary States of EA-type Eclipsing Binaries Observed by LAMOSTDec 25 2017About 3196 EA-type binaries (EAs) were observed by LAMOST by June 16, 2017 and their spectral types were derived. Meanwhile stellar atmospheric parameters of 2020 EAs were determined. In the paper, those EAs are catalogued and their physical properties ... More
Topological nature of FeSe$_{0.5}$Te$_{0.5}$ superconductorJun 22 2015We demonstrate, using first-principles calculations, that the electronic structure of FeSe$_{1-x}$Te$_{x}$ ($x$=0.5) is topologically non-trivial, characterized by an odd $\mathbb Z_2$ invariant and Dirac cone type surface states, in sharp contrast to ... More
Berry Phase Effect on Exciton Transport and Bose Einstein CondensateJan 08 2008Jul 28 2008With exciton lifetime much extended in semiconductor quantum-well structures, their transport and Bose-Einstein condensation become a focus of research in recent years. We reveal a momentum-space gauge field in the exciton center-of-mass dynamics due ... More
Interfacial-state coupling induced topological phase transitions in SnTe (110) thin filmNov 10 2016A defining feature of topological insulating phases is symmetry-protected interfacial Dirac states. SnTe is a representative topological crystalline insulator, of which (110) thin films have two symmetry-unrelated valleys of interfacial states. With the ... More
Geometrical phase effects on the Wigner distribution of Bloch electronsMay 22 2006We investigate the dynamics of Bloch electrons using a density operator method and connect this approach with previous theories based on wave packets. We study non-interacting systems with negligible disorder and strong spin-orbit interactions, which ... More
Charge-Hall effect driven by spin force: reciprocal of the spin-Hall effectJun 18 2004A new kind of charge-Hall effect is shown. Unlike in the usual Hall effect, the driving force in the longitudinal direction is a spin force, which may originate from the gradient of a Zeeman field or a spin-dependent chemical potential. The transverse ... More
Fast Parallel Algorithms for Feature SelectionMar 06 2019In this paper, we analyze a fast parallel algorithm to efficiently select and build a set of $k$ random variables from a large set of $n$ candidate elements. This combinatorial optimization problem can be viewed in the context of feature selection for ... More
Entropy Productions and Their Mathematical Representations: Clausius' vs. Kelvin's Views of the Second Law and IrreversibilityMay 24 2018We provide a stochastic mathematical theory for the nonequilibrium steady-state dissipation in a finite, compact driven system in terms of the non-stationary irreversibility in its external drive. A surjective map is rigorously established through a lift ... More
The least common multiple of consecutive arithmetic progression termsMar 03 2009Feb 18 2010Let $k\ge 0,a\ge 1$ and $b\ge 0$ be integers. We define the arithmetic function $g_{k,a,b}$ for any positive integer $n$ by $g_{k,a,b}(n):=\frac{(b+na)(b+(n+1)a)...(b+(n+k)a)} {{\rm lcm}(b+na,b+(n+1)a,...,b+(n+k)a)}.$ Letting $a=1$ and $b=0$, then $g_{k,a,b}$ ... More
Alon-Tarsi number of signed planar graphsSep 09 2018Let $(G,\sigma)$ be any signed planar graph. We show that the Alon-Tarsi number of $(G,\sigma)$ is at most 5, generalizing a recent result of Zhu for unsigned case. In addition, if $(G,\sigma)$ is $2$-colorable then $(G,\sigma)$ has the Alon-Tarsi number ... More
Boundary Hölder gradient estimates for the Monge-Ampère equationOct 25 2018We investigate global H\"older gradient estimates for solutions to the Monge-Amp\`ere equation $$\mathrm{det}\;D^2 u=f\quad\mathrm{in}\;\Omega,$$ where the right-hand side $f$ is bounded away from $0$ and $\infty$. We consider two main situations when ... More
Global $W^{2,p}$ regularity on the linearized Monge-Amp$\grave{e}$re equation with $\mathrm{VMO}$ type coefficientsOct 10 2018In this paper, we establish global $W^{2,p}$ estimates for solutions of the linearized Monge-Amp$\grave{e}$re equation $$\mathcal{L}_{\phi}u:=\mathrm{tr}[\Phi D^2 u]=f,$$ where the density of the Monge-Amp$\grave{e}$re measure $g:=\mathrm{det}D^2\phi$ ... More
Global $C^{1+α,\frac{1+α}{2}}$ regularity on the linearized parabolic Monge-Amp$\grave{e}$re equationOct 10 2018In this paper, we establish global $C^{1+\alpha,\frac{1+\alpha}{2}}$ estimates for solutions of the linearized parabolic Monge-Amp$\grave{e}$re equation $$\mathcal{L}_\phi u(x,t):=-u_t\,\mathrm{det}D^2\phi(x)+\mathrm{tr}[\Phi(x) D^2 u]=f(x,t)$$ under ... More
Efficient Minimax Signal Detection on GraphsNov 23 2014Several problems such as network intrusion, community detection, and disease outbreak can be described by observations attributed to nodes or edges of a graph. In these applications presence of intrusion, community or disease outbreak is characterized ... More
Spectral Clustering with Imbalanced DataSep 09 2013Spectral clustering is sensitive to how graphs are constructed from data particularly when proximal and imbalanced clusters are present. We show that Ratio-Cut (RCut) or normalized cut (NCut) objectives are not tailored to imbalanced data since they tend ... More
Spectral Clustering with Unbalanced DataFeb 20 2013Spectral clustering (SC) and graph-based semi-supervised learning (SSL) algorithms are sensitive to how graphs are constructed from data. In particular if the data has proximal and unbalanced clusters these algorithms can lead to poor performance on well-known ... More
On Some Inverse Eigenvalue Problems of Quadratic Palindromic SystemsJun 13 2016This paper concerns some inverse eigenvalue problems of the quadratic $\star$-(anti)-palindromic system $Q(\lambda)=\lambda^2 A_1^{\star}+\lambda A_0 + \epsilon A_1$, where $\epsilon=\pm 1$, $A_1, A_0 \in \mathbb{C}^{n\times n}$, $A_0^{\star}=\epsilon ... More
Magnetic Fluctuations, Precursor Phenomena and Phase Transition in MnSi under Magnetic FieldJun 25 2016Jul 27 2017The reference chiral helimagnet MnSi is the first system where skyrmion lattice correlations have been reported. At zero magnetic field the transition at $T_C$ to the helimagnetic state is of first order. Above $T_C$, in a region dominated by precursor ... More