Results for "Song Bai"

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The Amplituhedron from Momentum Twistor DiagramsAug 11 2014We propose a new diagrammatic formulation of the all-loop scattering amplitudes/Wilson loops in planar N=4 SYM, dubbed the "momentum-twistor diagrams". These are on-shell-diagrams obtained by gluing trivalent black and white vertices defined in momentum ... More
Analysis of Sequential Quadratic Programming through the Lens of Riemannian OptimizationMay 22 2018Jan 31 2019We prove that a "first-order" Sequential Quadratic Programming (SQP) algorithm for equality constrained optimization has local linear convergence with rate $(1-1/\kappa_R)^k$, where $\kappa_R$ is the condition number of the Riemannian Hessian, and global ... More
Triplet-Center Loss for Multi-View 3D Object RetrievalMar 16 2018Most existing 3D object recognition algorithms focus on leveraging the strong discriminative power of deep learning models with softmax loss for the classification of 3D data, while learning discriminative features with deep metric learning for 3D object ... More
Machine Learning Regression of stellar effective temperatures in the second $Gaia$ Data ReleaseJun 24 2019This paper reports on the application of the supervised machine-learning algorithm to the stellar effective temperature regression for the second $Gaia$ data release, based on the combination of the stars in four spectroscopic surveys: Large Sky Area ... More
The Amplituhedron and the One-loop Grassmannian MeasureOct 13 2015All-loop planar scattering amplitudes in maximally supersymmetric Yang-Mills theory can be formulated geometrically in terms of the "amplituhedron". We study the mathematical structures of the one-loop amplituhedron, and present a new formula for its ... More
Proximal algorithms for constrained composite optimization, with applications to solving low-rank SDPsMar 01 2019We study a family of (potentially non-convex) constrained optimization problems with convex composite structure. Through a novel analysis of non-smooth geometry, we show that proximal-type algorithms applied to exact penalty formulations of such problems ... More
Machine Learning Classification of Gaia Data Release 2Aug 17 2018Machine learning has increasingly gained more popularity with its incredibly powerful ability to make predictions or calculated suggestions for large amounts of data. We apply the machine learning classification to 85,613,922 objects in the $Gaia$ data ... More
Two Optical Counterpart Candidates of M82-X1 from HST ObservationsOct 01 2015Optical counterparts can provide significant constraints on the physical nature of ultraluminous X-ray sources (ULXs). In this letter, we identify six point sources in the error circle of a ULX in M82, namely M82 X-1, by registering Chandra positions ... More
A Combined Chandra and LAMOST Study of Stellar ActivityDec 14 2018We probed stellar X-ray activity over a wide range of stellar parameters, using {\it Chandra} and LAMOST data. We measured the X-ray-to-bolometric luminosity ratio ($R_X = L_X/L_{\rm bol}$) for 484 main-sequence stars, and found a bimodal distribution ... More
An investigation of a magnetic cataclysmic variable with a period of 14.1 ksOct 17 2016Magnetic cataclysmic variables (CVs) contain a white dwarf with magnetic field strong enough to control the accretion flow from a late type secondary. In this paper, we discover a magnetic CV (CXOGSG J215544.4+380116) from the $Chandra$ archive data. ... More
Learn to Interpret Atari AgentsDec 29 2018Jan 24 2019Deep Reinforcement Learning (DeepRL) agents surpass human-level performances in a multitude of tasks. However, the direct mapping from states to actions makes it hard to interpret the rationale behind the decision making of agents. In contrast to previous ... More
An Updated Ultraviolet Catalog of GALEX Nearby GalaxiesAug 28 2015The ultraviolet catalog of nearby galaxies made by \citet{Gil07} presents the integrated photometry and surface brightness profiles for 1034 nearby galaxies observed by \textit{Galaxy Evolution Explorer} (\textit{GALEX}). We provide an updated catalog ... More
Machine learning Applied to Star-Galaxy-QSO Classification and Stellar Effective Temperature RegressionNov 09 2018In modern astrophysics, the machine learning has increasingly gained more popularity with its incredibly powerful ability to make predictions or calculated suggestions for large amounts of data. We describe an application of the supervised machine-learning ... More
On the quantization accuracy of the acoustoelectric currentJul 16 2008By deriving analytical formulae for the quantization accuracy of the acoustoelectric current, we reveal that: 1) the flatness of the current plateau for the typical present devices has reached the theoretical limit of about 100ppm over a 1/1000 change ... More
Learning Attraction Field Representation for Robust Line Segment DetectionDec 05 2018Mar 05 2019This paper presents a region-partition based attraction field dual representation for line segment maps, and thus poses the problem of line segment detection (LSD) as the region coloring problem. The latter is then addressed by learning deep convolutional ... More
Simultaneously high electron and hole mobilities in cubic boron-V compounds: BP, BAs and BSbJul 08 2018Through first-principles calculations, the phonon-limited transport properties of cubic boron-V compounds (BP, BAs and BSb) are studied. We find that the high optical phonon frequency in these compounds leads to the substantial suppression of polar scattering ... More
AID: A Benchmark Dataset for Performance Evaluation of Aerial Scene ClassificationAug 18 2016Aerial scene classification, which aims to automatically label an aerial image with a specific semantic category, is a fundamental problem for understanding high-resolution remote sensing imagery. In recent years, it has become an active task in remote ... More
GraphHP: A Hybrid Platform for Iterative Graph ProcessingJun 22 2017The Bulk Synchronous Parallel(BSP) computational model has emerged as the dominant distributed framework to build large-scale iterative graph processing systems. While its implementations(e.g., Pregel, Giraph, and Hama) achieve high scalability, frequent ... More
ATRank: An Attention-Based User Behavior Modeling Framework for RecommendationNov 17 2017Nov 27 2017A user can be represented as what he/she does along the history. A common way to deal with the user modeling problem is to manually extract all kinds of aggregated features over the heterogeneous behaviors, which may fail to fully represent the data itself ... More
CenterNet: Keypoint Triplets for Object DetectionApr 17 2019Apr 19 2019In object detection, keypoint-based approaches often suffer a large number of incorrect object bounding boxes, arguably due to the lack of an additional look into the cropped regions. This paper presents an efficient solution which explores the visual ... More
Integrable Open Spin Chains from Flavored ABJM TheoryApr 19 2017Apr 27 2017We compute the two-loop anomalous dimension matrix in the scalar sector of planar ${\cal N}=3$ flavored ABJM theory. Using coordinate Bethe ansatz, we obtain the reflection matrix and confirm that the boundary Yang-Baxter equations are satisfied. This ... More
Phonon Hydrodynamic Heat Conduction and Knudsen Minimum in GraphiteNov 02 2017Dec 21 2017In the hydrodynamic regime, phonons drift with a nonzero collective velocity under a temperature gradient, reminiscent of viscous gas and fluid flow. The study of hydrodynamic phonon transport has spanned over half a century but has been mostly limited ... More
QED cascade induced by high energy $γ$ photon in strong laser fieldDec 09 2013The QED cascade induced by the two counter-propagating lasers is studied. It is demonstrated that the probability of a seed-photon to create a pair is much larger than that of a seed-electron. By analyzing the dynamic characteristics of the electron and ... More
DeepCenterline: a Multi-task Fully Convolutional Network for Centerline ExtractionMar 25 2019A novel centerline extraction framework is reported which combines an end-to-end trainable multi-task fully convolutional network (FCN) with a minimal path extractor. The FCN simultaneously computes centerline distance maps and detects branch endpoints. ... More
Personalized Bundle List RecommendationApr 03 2019Product bundling, offering a combination of items to customers, is one of the marketing strategies commonly used in online e-commerce and offline retailers. A high-quality bundle generalizes frequent items of interest, and diversity across bundles boosts ... More
Longitudinal wave instability in magnetized high correlation dusty plasmaJun 18 2003Low frequency longitudinal wave instability in magnetized high correlation dusty plasmas is investigated. The dust charging relaxation is taken into account. It is found that the instablity of wave is determined significantly by the frequency of wave, ... More
Graph Edit Distance Computation via Graph Neural NetworksAug 16 2018Oct 03 2018Graph similarity search is among the most important graph-based applications, e.g. finding the chemical compounds that are most similar to a query compound. Graph similarity/distance computation, such as Graph Edit Distance (GED) and Maximum Common Subgraph ... More
Improving Transferability of Adversarial Examples with Input DiversityMar 19 2018Jun 01 2019Though CNNs have achieved the state-of-the-art performance on various vision tasks, they are vulnerable to adversarial examples --- crafted by adding human-imperceptible perturbations to clean images. However, most of the existing adversarial attacks ... More
Prior-aware Neural Network for Partially-Supervised Multi-Organ SegmentationApr 12 2019Accurate multi-organ abdominal CT segmentation is essential to many clinical applications such as computer-aided intervention. As data annotation requires massive human labor from experienced radiologists, it is common that training data are partially ... More
Angular Distributions of Thomson Scattering in Combined Laser and Magnetic fieldsOct 19 2018Angular distributions of Thomson scattering are researched in the combined fields with a circularly polarization of laser field and a strong uniform magnetic field. The trajectories of the electron and the dependence of it on the initial phase are also ... More
Centrality dependence of charmed-meson photoproduction in ultrarelativistic heavy ion collisionsJul 11 2017We calculate the centrality dependence of inclusive cross section of large-pT charmed-meson ($D^{0}$, $D^{*}$, $D^{*+}$, and $D_{s}^{+}$) from heavy quark fragmentation by the hard photoproduction processes for the nucleus-nucleus collisions in ultrarelativistic ... More
Impurity scattering and Friedel oscillations in mono-layer black phosphorusMar 15 2016Mar 17 2016We study the effect of impurity scattering effect in black phosphorurene (BP) in this work. For single impurity, we calculate impurity induced local density of states (LDOS) in momentum space numerically based on tight-binding Hamiltonian. In real space, ... More
Anisotropic-Scale Junction Detection and Matching for Indoor ImagesMar 16 2017Sep 17 2017Junctions play an important role in the characterization of local geometric structures in images, the detection of which is a longstanding and challenging task. Existing junction detectors usually focus on identifying the junction locations and the orientations ... More
Semi-Supervised Multi-Organ Segmentation via Deep Multi-Planar Co-TrainingApr 07 2018Nov 19 2018In multi-organ segmentation of abdominal CT scans, most existing fully supervised deep learning algorithms require lots of voxel-wise annotations, which are usually difficult, expensive, and slow to obtain. In comparison, massive unlabeled 3D CT volumes ... More
Thomson backscattering in combined two laser and magnetic fieldMay 05 2019The Thomson backscattering of an electron moving in combined fields is studied by a dynamically assisted mechanism. The combined fields are composed of two co-propagating laser fields and a magnetic field, where the first laser field is strong and low-frequency ... More
Initial carrier-envelope phase of few-cycle pulses determined by THz emission from air plasmaJul 05 2013The evolution of THz waveform generated in air plasma provides a sensitive probe to the variation of the carrier envelope phase (CEP) of propagating intense few-cycle pulses. Our experimental observation and calculation reveal that the number and positions ... More
Chandra ACIS Survey of X-ray Point Sources: The Source CatalogMar 28 2016The $Chandra$ archival data is a valuable resource for various studies on different topics of X-ray astronomy. In this paper, we utilize this wealth and present a uniformly processed data set, which can be used to address a wide range of scientific questions. ... More
Enhanced correlation of electron-positron pair in the two and three dimensionsOct 15 2013Early-time electron-positron correlation in vacuum pair-production in an external field is investigated. The entangled electron and positron wave functions are obtained analytically in the configuration and momentum spaces. It is shown that, relative ... More
Scalable Person Re-identification on Supervised Smoothed ManifoldMar 24 2017Most existing person re-identification algorithms either extract robust visual features or learn discriminative metrics for person images. However, the underlying manifold which those images reside on is rarely investigated. That raises a problem that ... More
X-ray Activity from Different Types of StarsFeb 03 2019X-ray emission is an important indicator of stellar activity. In this paper, we study stellar X-ray activity using the XMM-Newton and LAMOST data for different types of stars. We provide a sample including 1259 X-ray emitting stars, of which 1090 have ... More
Giant negative thermal expansion covering room temperature in nanocrystalline GaNxMn3Aug 05 2015Materials with negative thermal expansion (NTE), which contract upon heating, are of great interest both technically and fundamentally. Here, we report giant NTE covering room temperature in mechanically milled antiperovksite GaNxMn3 compounds. The micrograin ... More
Improving the staggered grid Lagrangian hydrodynamics for modeling multi-material flowsJul 07 2017In this work, we make two improvements on the staggered grid hydrodynamics (SGH) Lagrangian scheme for modeling 2-dimensional compressible multi-material flows on triangular mesh. The first improvement is the construction of a dynamic local remeshing ... More
Attention-driven Tree-structured Convolutional LSTM for High Dimensional Data UnderstandingJan 29 2019Modeling the sequential information of image sequences has been a vital step of various vision tasks and convolutional long short-term memory (ConvLSTM) has demonstrated its superb performance in such spatiotemporal problems. Nevertheless, the hierarchical ... More
Enhanced Conductance Fluctuation by Quantum Confinement Effect in Graphene NanoribbonsOct 08 2010Conductance fluctuation is usually unavoidable in graphene nanoribbons (GNR) due to the presence of disorder along its edges. By measuring the low-frequency noise in GNR devices, we find that the conductance fluctuation is strongly correlated with the ... More
$η_{Q}$ meson photoproduction in ultrarelativistic heavy ion collisionsAug 20 2017Jan 03 2018The transverse momentum distributions for inclusive $\eta_{c,b}$ meson described by gluon-gluon interactions from photoproduction processes in relativistic heavy ion collisions are calculated. We considered the color singlet (CS) and color octet (CO) ... More
Thomson backscattering in combined uniform magnetic and envelope modulating circularly-polarized laser fieldsDec 23 2018The Thomson backscattering spectra in combined uniform magnetic and cosine-envelope circularly-polarized laser fields are studied in detail. With an introduction of the envelope modulation, the radiation spectra exhibit high complexity attributed to the ... More
Modulation effect in multiphoton pair productionJan 13 2017We investigate the electron-positron pair production process in an oscillating field with modulated amplitude in quantum kinetic formalism. By comparing the number density in field with and without modulation, we find that the pair production rate can ... More
The high density $γ$-ray emission and dense positron production via multi-lasers driven circular targetDec 04 2018A diamond-like carbon circular target is proposed to improve the $\gamma$-ray emission and pair production with lasers intensity of $8\times 10^{22} ~\mathrm{W/cm^2}$ by using two-dimensional particle-in-cell simulations with quantum electrodynamics. ... More
Waveform-Controlled Terahertz Radiation from the Air Filament Produced by Few-Cycle Laser PulsesApr 09 2012Waveform-controlled Terahertz (THz) radiation is of great importance due to its potential application in THz sensing and coherent control of quantum systems. We demonstrated a novel scheme to generate waveform-controlled THz radiation from air plasma ... More
High-frequency Oscillations in the Atmosphere above a Sunspot UmbraMar 24 2018We use high spatial and temporal resolution observations, simultaneously obtained with the New Vacuum Solar Telescope and Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, to investigate the high-frequency oscillations above ... More
Multidimensional Scaling on Multiple Input Distance MatricesMay 01 2016Aug 26 2017Multidimensional Scaling (MDS) is a classic technique that seeks vectorial representations for data points, given the pairwise distances between them. However, in recent years, data are usually collected from diverse sources or have multiple heterogeneous ... More
Deep Learning Representation using Autoencoder for 3D Shape RetrievalSep 25 2014We study the problem of how to build a deep learning representation for 3D shape. Deep learning has shown to be very effective in variety of visual applications, such as image classification and object detection. However, it has not been successfully ... More
A Method to Search for Black Hole Candidates with Giant Companions by LAMOSTFeb 07 2019We propose a method to search for stellar-mass black hole (BH) candidates with giant companions from spectroscopic observations. Based on the stellar spectra of LAMOST Data Release 6, we obtain a sample of seven giants in binaries with large radial velocity ... More
Divide and Fuse: A Re-ranking Approach for Person Re-identificationAug 11 2017As re-ranking is a necessary procedure to boost person re-identification (re-ID) performance on large-scale datasets, the diversity of feature becomes crucial to person reID for its importance both on designing pedestrian descriptions and re-ranking based ... More
Multidimensional Scaling on Multiple Input Distance MatricesMay 01 2016Multidimensional Scaling (MDS) is a classic technique that seeks vectorial representations for data points, given the pairwise distances between them. However, in recent years, data are usually collected from diverse sources or have multiple heterogeneous ... More
Heat conduction in one-dimensional Yukawa chainsDec 02 2003Heat conduction in one-dimensional Yukawa chains is investigated. It is shown numerically that it has the abnormal heat conduction which is proportional to the system size. Effects of asymmetric external potential, the modified Frenkel-Kontorova one, ... More
The Landscape of Empirical Risk for Non-convex LossesJul 22 2016Jan 14 2017Most high-dimensional estimation and prediction methods propose to minimize a cost function (empirical risk) that is written as a sum of losses associated to each data point. In this paper we focus on the case of non-convex losses, which is practically ... More
Gaia Calibrated UV Luminous Stars in LAMOSTJul 02 2018We take advantage of the Gaia data release 2 to present 275 and 1,774 ultraviolet luminous stars in the FUV and the NUV. These stars are 5$\sigma$ exceeding the centers of the reference frame that is built with over one million UV stars in the log $g$ ... More
CG X-1: an eclipsing Wolf-Rayet ULX in the Circinus galaxyApr 01 2019Apr 30 2019We investigated the time-variability and spectral properties of the eclipsing X-ray source Circinus Galaxy X-1 (GG X-1), using Chandra, XMM-Newton and ROSAT. We phase-connected the lightcurves observed over 20 years, and obtained a best-fitting period ... More
Nanostructured Polymer Films with Metal-like Thermal ConductivityAug 21 2017Thermally conductive polymers are of fundamental interest and can also be exploited in thermal management applications. Recent studies have shown stretched polymers can achieve high thermal conductivity. However, the transport mechanisms of heat in thermally ... More
Dynamic Large Spatial Covariance Matrix Estimation in Application to Semiparametric Model Construction via Variable Clustering: the SCE approachJun 20 2011Jun 23 2011To better understand the spatial structure of large panels of economic and financial time series and provide a guideline for constructing semiparametric models, this paper first considers estimating a large spatial covariance matrix of the generalized ... More
Spectroscopic Studies of an Ultraluminous Supersoft X-Ray Source in M81Aug 31 2015Ultraluminous supersoft X-ray sources (ULSs) exhibit supersoft X-ray spectra with blackbody temperatures below 0.1 keV and bolometric luminosities above 10$^{39}$ ergs s$^{-1}$. In this Letter, we report the first optical spectroscopic observations of ... More
The Landscape of Empirical Risk for Non-convex LossesJul 22 2016Jul 25 2016We revisit the problem of learning a noisy linear classifier by minimizing the empirical risk associated to the square loss. While the empirical risk is non-convex, we prove that its structure is remarkably simple. Namely, when the sample size is larger ... More
Effects of finite spatial extent on Schwinger pair productionMay 05 2019Electron-positron pair production from vacuum in external electric fields with space and time dependencies is studied numerically using real time Dirac-Heisenberg-Wigner formalism. The influence of spatial focusing scale of the electric field on momentum ... More
The Classification of n-Lie AlgebrasJun 10 2010This paper proves the isomorphic criterion theorem for (n+2)-dimensional n-Lie algebras, and gives a complete classification of (n+1)-dimensional n-Lie algebras and (n+2)-dimensional n-Lie algebras over an algebraically closed field of characteristic ... More
iSAID: A Large-scale Dataset for Instance Segmentation in Aerial ImagesMay 30 2019Existing Earth Vision datasets are either suitable for semantic segmentation or object detection. In this work, we introduce the first benchmark dataset for instance segmentation in aerial imagery that combines instance-level object detection and pixel-level ... More
Enhanced laser radiation pressure acceleration of protons with a gold cone-capillaryJan 15 2017A scheme with gold cone-capillary is proposed to improve the protons acceleration and involved problems are investigated by using the two-dimensional particle-in-cell simulations. It is demonstrated that the cone-capillary can efficiently guide and collimate ... More
On the role of secondary electron emission in capacitively coupled radio frequency plasma sheath: a theoretical groundMay 28 2019Jun 30 2019We propose a theoretical ground for emissive capacitively coupled radio-frequency plasma sheath under low pressure. The rf sheath is assumed to be collisionless, and oscillates with external source. A known sinusoidal voltage instead of current is taken ... More
Effects of finite spatial extent on Schwinger pair productionMay 05 2019May 19 2019Electron-positron pair production from vacuum in external electric fields with space and time dependencies is studied numerically using real time Dirac-Heisenberg-Wigner formalism. The influence of spatial focusing scale of the electric field on momentum ... More
A Large Sample of Am Candidates from LAMOST Data Release 1Jan 26 2015We present a sample of metallic-line star (Am) candidates from the Large sky Area Multi-Object fiber Spectroscopic Telescope Data Release one (LAMOST DR1). According to the characteristic of under-abundance of calcium and overabundance of iron element ... More
Observation of second sound in graphite at temperatures above 100 KJan 26 2019Wavelike thermal transport in solids, referred to as second sound, has until now been an exotic phenomenon limited to a handful of materials at low temperatures. This has restricted interest in its occurrence and in its potential applications. Through ... More
The UV Emission of Stars in LAMOST Survey I. CatalogsFeb 02 2018We present the ultraviolet magnitudes for over three million stars in the LAMOST survey, in which 2,202,116 stars are detected by $GALEX$. For 889,235 undetected stars, we develop a method to estimate their upper limit magnitudes. The distribution of ... More
Mimicing the Kane-Mele type spin orbit interaction by spin-flexual phonon coupling in graphene devicesMar 28 2015Jun 08 2017On the efforts of enhancing the spin orbit interaction (SOI) of graphene for seeking the dissipationless quantum spin Hall devices, unique Kane-Mele type SOI and high mobility samples are desired. However, common external decoration often introduces extrinsic ... More
Extremes of $L^p$-norm of Vector-valued Gaussian processes with TrendJun 26 2017Jun 01 2018Let $\boldsymbol{X}(t)=(X_1(t),\ldots,X_d(t))$ be a Gaussian vector process and $g(t)$ be a continuous function. The asymptotics of distribution of $\left\|\boldsymbol{X}(t)\right\|_p$, the $L^p$ norm for Gaussian finite-dimensional vector, have been ... More
High-Q microcavity enhanced optical properties of CuInS$_{2}$/ZnS colloidal quantum dots towards non-photodegradationJan 13 2017We report on a temporal evolution of photoluminescence (PL) spectroscopy of CuInS$_{2}$/ZnS colloidal quantum dots (QDs) by drop-casting on SiO$_{2}$/Si substrates and high quality factor microdisks (MDs) under different atmospheric conditions. Fast PL ... More
Presence of Exotic Electronic Surface States in LaBi and LaSbJul 14 2016Nov 01 2016Extremely high magnetoresistance (XMR) in the lanthanum monopnictides La$X$ ($X$ = Sb, Bi) has recently attracted interest in these compounds as candidate topological materials. However, their perfect electron-hole compensation provides an alternative ... More
Edge effect on resistance scaling rules in graphene nanostructuresFeb 14 2011We report an experimental investigation of the edge effect on the room-temperature transport in graphene nanoribbon and graphene sheet (both single-layer and bilayer). By measuring the resistance scaling behaviors at both low and high carrier densities, ... More
Particle Motion in Generalized Dirac's Monopoles of dimension 2k+1Nov 16 2015Nov 17 2015By using Meng's idea in his generalization of the classical MICZ-Kepler problem, we obtained the equations of motion of a charged particle in the field of generalized Dirac monopole in odd dimensional Euclidean spaces. The main result is that for every ... More
$K_L$ - $K_S$ mass difference computed with a 171 MeV pion massNov 12 2014In this work, we used a $32^3 \times 64 \times 32$, 2+1 flavor domain wall lattice with Iwasaki+DSDR gauge action. The pion mass is 171 MeV and the kaon mass is 492 MeV. We implement the Glashow-Iliopoulos-Maiani (GIM) cancellation using charm quark masses ... More
A note on hypergraph coloringsAug 12 2018Let $t\geqslant 2$ and $s\geqslant 1$ be two integers. Define a $(t,s)$-coloring of a hypergraph to be a coloring of its vertices using $t$ colors such that each color appears on each edge at least $s$ times. In this note, we provide a sufficient condition ... More
Mini Little Higgs and Dark MatterJan 10 2008Aug 25 2008We construct a little Higgs model with the most minimal extension of the standard model gauge group by an extra U(1) gauge symmetry. For specific charge assignments of scalars, an approximate U(3) global symmetry appears in the cutoff-squared scalar mass ... More
Softness, Polynomial Boundedness and Amplitudes' PositivityJul 25 2016Dec 13 2017In this note, we study the connections between infrared (IR) and ultraviolet (UV) behaviors of scattering amplitudes of massless channels by exploiting dispersion relations and positivity bounds. Given forward scattering amplitudes, which scale as $\mathcal{A}(s)\sim ... More
Extremes of multifractional Brownian motionNov 15 2017Mar 30 2019Let $B_{H}(t), t\geq [0,T], T\in(0,\infty)$ be the standard Multifractional Brownian Motion(mBm), in this contribution we are concerned with the exact asymptotics of \begin{eqnarray*} \mathbb{P}\left\{\sup_{t\in[0,T]}B_{H}(t)>u\right\} \end{eqnarray*} ... More
Estimation of Change-point ModelsMay 01 2018May 08 2018We consider the testing and estimation of change-points, locations where the distribution abruptly changes, in a sequence of observations. Motivated by this problem, in this contribution we first investigate the extremes of Gaussian fields with trend ... More
Parisian ruin of Brownian motion risk model over an infinite-time horizonFeb 20 2017Let $B(t), t\in \mathbb{R}$ be a standard Brownian motion. In this paper, we derive the exact asymptotics of the probability of Parisian ruin on infinite time horizon for the following risk process \begin{align}\label{Rudef} R_u^{\delta}(t)=e^{\delta ... More
Extremes of $α(t)$-Locally stationary Gaussian processes with non-constant variancesJun 22 2016Aug 21 2016With motivation from K. D\c{e}bicki and P. Kisowski (2007), in this paper we derive the exact tail asymptotics of $\alpha(t)$-locally stationary Gaussian processes with non-constant variance functions. We show that some certain variance functions lead ... More
A Uniqueness Property for the Quantization of Teichmüller SpacesSep 28 2005Chekhov, Fock and Kashaev introduced a quantization of the Teichm\"{u}ller space $\mathcal{T}^q(S)$ of a punctured surface $S$, and an exponential version of this construction was developed by Bonahon and Liu. The construction of the quantum Teichm\"{u}ller ... More
The anisotropic flow coefficients $v_2$ and $v_4$ in Au+Au collisions at RHICJan 23 2007We present measurements by STAR of the anisotropic flow coefficients $v_2$ and $v_4$ as a function of particle-type, centrality, transverse momentum and pseudorapidity in Au+Au collisions at RHIC.
Real-Time Fine-Grained Air Quality Sensing Networks in Smart City: Design, Implementation and OptimizationOct 18 2018Feb 27 2019Driven by the increasingly serious air pollution problem, the monitoring of air quality has gained much attention in both theoretical studies and practical implementations. In this paper, we present the architecture, implementation and optimization of ... More
Electron-positron pair creation characterized by the conversion energyMay 22 2016It is demonstrated that a pair can be characterized under which mechanism it was created according to its conversion energy, a quantity defined as the sum of electron and its conjugate positron's mass-energy, in the study of electron-positron pair creation. ... More
Pair production in differently polarized electric fields with frequency chirpsNov 29 2018Electron-positron pair production in strong electric fields, i.e., the Sauter-Schwinger effect, is studied using the real-time Dirac-Heisenberg-Wigner formalism. Hereby, the electric field is modeled to be a homogeneous, single-pulse field with subcritical ... More
Towards Economic Models for MOOC Pricing Strategy DesignJan 15 2017MOOCs have brought unprecedented opportunities of making high-quality courses accessible to everybody. However, from the business point of view, MOOCs are often challenged for lacking of sustainable business models, and academic research for marketing ... More
Real-Time Prediction for Fine-Grained Air Quality Monitoring System with Asynchronous SensingNov 06 2018Due to the significant air pollution problem, monitoring and prediction for air quality have become increasingly necessary. To provide real-time fine-grained air quality monitoring and prediction in urban areas, we have established our own Internet-of-Things-based ... More
Scattering Forms and the Positive Geometry of Kinematics, Color and the WorldsheetNov 24 2017Mar 28 2018The search for a theory of the S-Matrix has revealed surprising geometric structures underlying amplitudes ranging from the worldsheet to the amplituhedron, but these are all geometries in auxiliary spaces as opposed to kinematic space where amplitudes ... More
Hypergraph Convolution and Hypergraph AttentionJan 23 2019Recently, graph neural networks have attracted great attention and achieved prominent performance in various research fields. Most of those algorithms have assumed pairwise relationships of objects of interest. However, in many real applications, the ... More
Effects of polarization and high harmonics of two-color fields on dynamically assisted pair productionMay 28 2019Jun 07 2019Electron-positron pair production in dynamically assisted two-color electric fields is investigated for various polarizations. Momentum spectrum and number density of the created pairs are examined carefully, in particular, the effects of polarization ... More
Quantum anomalous Hall multilayers grown by molecular beam epitaxyJun 15 2018Quantum anomalous Hall (QAH) effect is a quantum Hall effect that occurs without the need of external magnetic field. A system composed of multiple parallel QAH layers is an effective high Chern number QAH insulator and the key to the applications of ... More
GIFT: A Real-time and Scalable 3D Shape Search EngineApr 07 2016Mar 31 2017Projective analysis is an important solution for 3D shape retrieval, since human visual perceptions of 3D shapes rely on various 2D observations from different view points. Although multiple informative and discriminative views are utilized, most projection-based ... More
GIFT: A Real-time and Scalable 3D Shape Search EngineApr 07 2016Projective analysis is an important solution for 3D shape retrieval, since human visual perceptions of 3D shapes rely on various 2D observations from different view points. Although multiple informative and discriminative views are utilized, most projection-based ... More
Hard-Aware Point-to-Set Deep Metric for Person Re-identificationJul 30 2018Person re-identification (re-ID) is a highly challenging task due to large variations of pose, viewpoint, illumination, and occlusion. Deep metric learning provides a satisfactory solution to person re-ID by training a deep network under supervision of ... More