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Observation of dynamical phase transitions in a topological nanomechanical systemJul 12 2018Aug 26 2018Dynamical phase transitions, characterized by non-analytic behaviors in time domain, extend the equilibrium phase transitions to far-from-equilibrium situations. Furthermore, it's predicted that the dynamical phase transitions can be precisely identified ... More

Measuring cosmological distances of active galactic nuclei from spectroastrometry and reverberation mapping: application to 3C 273Jun 20 2019Using spectroastrometry, the GRAVITY at The Very Large Telescope Interferometry successfully revealed the structure and kinematics of the broad-line region (BLR) of 3C 273 with an unprecedented high spatial resolution. Spectroastrometry measures the BLR ... More

Landau-Zener-Stuckelberg interferometry of a single electron spin in a noisy environmentJun 08 2011We demonstrate quantum coherent control of a single electron spin in a NV center in diamond using the Landau-Zener-Stuckelberg interferometry at room temperature. Interference pattern is observed oscillating as a function of microwave frequency. The decays ... More

Non-reciprocal Radio Frequency Transduction in a Parametric Mechanical Artificial LatticeFeb 21 2016Generating non-reciprocal radio frequency transduction plays important roles in a wide range of research and applications, and an aspiration is to integrate this functionality into micro-circuit without introducing magnetic field, which, however, remains ... More

Observation of Time-domain Rabi Oscillations in the Landau-Zener Regime with a Single Electronic SpinMay 01 2013Under resonant conditions, a long sequence of landau-zener transitions can lead to Rabi oscillations. Using a nitrogen-vacancy (NV) center spin in diamond, we investigated the interference between more than 100 Landau-Zener processes. We observed the ... More

Outflows from active galactic nuclei: The BLR-NLR metallicity correlationDec 11 2013The metallicity of active galactic nuclei (AGNs), which can be measured by emission line ratios in their broad and narrow line regions (BLRs and NLRs), provides invaluable information about the physical connection between the different components of AGNs. ... More

Dispersive Limit of the Euler-Poisson System in Higher DimensionsApr 24 2012In this paper, we consider the dispersive limit of the Euler-Poisson system for ion-acoustic waves. We establish that under the Gardner-Morikawa type transformations, the solutions of the Euler-Poisson system converge globally to the Kadomtsev-Petviashvili ... More

Characterization of Lipschitz spaces via commutators of the Hardy-Littlewood maximal functionDec 03 2016Jan 21 2017Let $M$ be the Hardy-Littlewood maximal function and $b$ be a locally integrable function. Denote by $M_b$ and $[b,M]$ the maximal commutator and the (nonlinear) commutator of $M$ with $b$. In this paper, the author consider the boundedness of $M_b$ and ... More

Room temperature test of wave-function collapse using a levitated micro-oscillatorJul 16 2019Wave-function collapse models predict a tiny break of energy conservation via a weak spontaneous stochastic force acting on the system, and are attracting experimental studies. Among various physical systems, mechanical based methods provide a direct ... More

On the geometric Ramsey numbers of treesAug 23 2013Nov 12 2013In this paper, we obtain upper bounds for the geometric Ramsey numbers of trees. We prove that $R_c(T_n,H_m)=(n-1)(m-1)+1$ if $T_n$ is a caterpillar and $H_m$ is a Hamiltonian outerplanar graph on $m$ vertices. Moreover, if $T_n$ has at most two non-leaf ... More

Supermassive black holes with high accretion rates in active galactic nuclei: II. the most luminous standard candles in the UniverseAug 11 2014This is the second in a series of papers reporting on a large reverberation mapping (RM) campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). The goal is to identify super-Eddington accreting massive black holes ... More

Relativistic fluid dynamics in heavy ion collisionsAug 30 2011This dissertation is about the study of three important issues in the theory of relativistic fluid dynamics: the stability of dissipative fluid dynamics, the shear viscosity, and fluid dynamics with triangle anomaly.(1)The second order theory of fluid ... More

Categorical resolutions of a class of derived categoriesOct 09 2014By using the relative derived categories, we prove that if an Artin algebra $A$ has a module $T$ with ${\rm inj.dim}T<\infty$ such that $^\perp T$ is finite, then the bounded derived category $D^b(A\mbox{-}{\rm mod})$ admits a categorical resolution in ... More

Generating Giant and Tunable Nonlinearity in a Macroscopic Mechanical Resonator from Chemical Bonding ForceJun 24 2015Nonlinearity in macroscopic mechanical system plays a crucial role in a wide variety of applications, including signal transduction and processing, synchronization, and building logical devices. However, it is difficult to generate nonlinearity due to ... More

A High-Quality velocity-delay map of the broad-line region in NGC 5548Sep 15 2018Sep 18 2018NGC 5548 has been well spectroscopically monitored for reverberation mapping of the central kinematics by 19 campaigns. Using the maximum entropy method in this Letter, we build up a high-quality velocity-delay map of the H$\beta$ emission line in the ... More

Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. IX 10 New Observations of Reverberation Mapping and Shortened H$β$ LagsFeb 08 2018As one of the series of papers reporting on a large reverberation mapping campaign of super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs), we present the results of 10 SEAMBHs monitored spectroscopically during 2015-2017. ... More

Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. VI. Velocity-resolved Reverberation Mapping of H$β$ LineFeb 05 2016In the sixth of the series of papers reporting on a large reverberation mapping (RM) campaign of active galactic nuclei (AGNs) with high accretion rates, we present velocity-resolved time lags of H$\beta$ emission lines for nine objects observed in the ... More

Long-range FMR driven spin pumping through a nonmagnetic insulatorMay 14 2013Apr 02 2014Ferromagnetic resonance (FMR) driven spin pumping is an emerging technique for injection of a pure spin current from a ferromagnet (FM) into a non-magnetic (NM) material without an accompanying charge current. It is widely believed that this pumping proceeds ... More

Kinematics of the Broad-line Region of 3C 273 from a Ten-year Reverberation Mapping CampaignNov 09 2018Mar 13 2019Despite many decades of study, the kinematics of the broad-line region of 3C~273 are still poorly understood. We report a new, high signal-to-noise, reverberation mapping campaign carried out from November 2008 to March 2018 that allows the determination ... More

Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. VIII. Structure of the Broad-Line Region and Mass of the Central Black Hole in Mrk 142Nov 15 2018This is the eighth in a series of papers reporting on a large reverberation mapping campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). We employ the recently developed dynamical modeling approach for broad-line ... More

Hidden Broad-line Regions in Seyfert 2 Galaxies: from the spectropolarimetric perspectiveApr 14 2017Apr 22 2017The hidden broad-line regions (BLRs) in Seyfert 2 galaxies, which display broad emission lines (BELs) in their polarized spectra, are a key piece of evidence in support of the unified model for active galactic nuclei (AGNs). However, the detailed kinematics ... More

Test of the Formation mechanism of the Broad Line Region in Active Galactic NucleiOct 03 2016The origin of the Broad Line Region (BLR) in active galaxies remains unknown. It seems to be related to the underlying accretion disk but an efficient mechanism is required to rise the material from the disk surface without giving too strong signatures ... More

Monitoring AGNs with Hβ Asymmetry. I. First Results: Velocity-resolved Reverberation MappingOct 29 2018We have started a long-term reverberation mapping project using the Wyoming Infrared Observatory 2.3 meter telescope titled "Monitoring AGNs with H\beta\ Asymmetry" (MAHA). The motivations of the project are to explore the geometry and kinematics of the ... More

Reverberation Mapping of the Broad-line Region in NGC 5548: Evidence for Radiation Pressure?Jul 27 2016NGC 5548 is the best-observed reverberation-mapped active galactic nucleus with long-term, intensive monitoring. Here we report results from a new observational campaign between January and July, 2015. We measure the centroid time lag of the broad H$\beta$ ... More

Supermassive black holes with high accretion rates in active galactic nuclei: X. Optical variability characteristicsApr 06 2019May 14 2019We compiled a sample of 73 active galactic nuclei (AGNs) with reverberation mapping (RM) observations from RM campaigns including our ongoing campaign of monitoring super-Eddington accreting massive black holes (SEAMBHs). This sample covers a large range ... More

Supermassive black holes with high accretion rates in active galactic nuclei. VII. Reconstruction of velocity-delay maps by maximum entropy methodAug 02 2018As one of the series of papers reporting on a large reverberation mapping campaign, we apply the maximum entropy method (MEM) to 9 narrow-line Seyfert 1 galaxies with super-Eddington accretion rates observed during 2012-2013 for the velocity-delay maps ... More

Eccentricities and Inclinations of Multi-Planet Systems with External PerturbersJan 18 2018Apr 16 2018Compact multi-planet systems containing super-Earths or sub-Neptunes, commonly found around solar-type stars, may be surrounded by external giant planet or stellar companions, which can shape the architechture and observability of the inner systems. We ... More

Types of Serre subcategories of Grothendieck categoriesMay 09 2017Every Serre subcategory of an abelian category is assigned a unique type. The type of a Serre subcategory of a Grothendieck category is in the list: $$(0, 0), \ (0, -1), \ (1, -1), \ (0, -2), \ (1, -2), \ (2, -1), \ (+\infty, -\infty);$$ and for each ... More

KdV limit of the Euler-Poisson systemFeb 08 2012Apr 23 2012Consider the scaling $\varepsilon^{1/2}(x-Vt)\to x,\ \varepsilon^{3/2}t\to t$ in the Euler-Poisson system for ion-acoustic waves \eqref{equ1}. We establish that as $\varepsilon\to 0$, the solutions to such Euler-Poisson system converge globally in time ... More

Hiding Planets Behind a Big Friend: Mutual Inclinations of Multi-Planet Systems with External CompanionsJun 28 2016Jul 14 2016The {\it Kepler} mission has detected thousands of planetary systems with 1-7 transiting planets packed within 0.7~au from their host stars. There is an apparent excess of single-transit planet systems that cannot be explained by transit geometries alone, ... More

Portfolio choice under drift uncertainty: a Bayesian learning and stochastic optimal control approachNov 23 2016Dec 05 2016This paper presents several models addressing optimal portfolio choice and optimal portfolio transition issues, in which the expected returns of risky assets are unknown. Our approach is based on a coupling between Bayesian learning and dynamic programming ... More

Commutators of multilinear Calderón-Zygmund operators with kernels of Dini's type and applicationsMay 24 2016Let $T$ be a multilinear Calder\'on-Zygmund operator of type $\omega$ with $\omega(t)$ being nondecreasing and satisfying a kind of Dini's type condition. Let $T_{\Pi\vec{b}}$ be the iterated commutators of $T$ with $BMO$ functions. The weighted strong ... More

The QKP limit of the quantum Euler-Poisson equationJun 22 2017In this paper, we consider the derivation of the Kadomtsev-Petviashvili (KP) equation for cold ion-acoustic wave in the long wavelength limit of the two-dimensional quantum Euler-Poisson system, under different scalings for varying directions in the Gardner-Morikawa ... More

Long wavelength limit for the quantum Euler-Poisson equationNov 02 2015In this paper, we consider the long wavelength limit for the quantum Euler-Poisson equation. Under the Gardner-Morikawa transform, we derive the quantum Korteweg-de Vries (KdV) equation by a singular perturbation method. We show that the KdV dynamics ... More

Ohmic Dissipation in Mini-NeptunesSep 06 2017In the presence of a magnetic field and weakly ionizing winds, ohmic dissipation is expected to take place in the envelopes of Jovian and lower-mass planets alike. While the process has been investigated on the former, there have been no studies done ... More

Hiding Planets Behind a Big Friend: Mutual Inclinations of Multi-Planet Systems with External CompanionsJun 28 2016Nov 03 2016The {\it Kepler} mission has detected thousands of planetary systems with 1-7 transiting planets packed within 0.7~au from their host stars. There is an apparent excess of single-transit planet systems that cannot be explained by transit geometries alone, ... More

Optimal lower bounds on hitting probabilities for stochastic heat equations in spatial dimension $k \geq 1$Nov 30 2018We establish a sharp estimate on the negative moments of the smallest eigenvalue of the Malliavin matrix $\gamma_Z$ of $Z := (u(s, y), u(t, x) - u(s, y))$, where $u$ is the solution to system of $d$ non-linear stochastic heat equations in spatial dimension ... More

Spin Mixing in Spinor Fermi GasesFeb 26 2013We study a spinor fermionic system under the effect of spin-exchange interaction. We focus on the interplay between the spin-exchange interaction and the effective quadratic Zeeman shift. We examine the static and the dynamic properties of both two- and ... More

Shear viscosity in late time of hydrodynamic evolution in AdS/CFT dualityOct 29 2008We investigate the shear viscosity $\eta$ and the entropy density $s$ of strongly coupled $\mathcal{N}=4$ super Yang-Mills (SYM) plasma in late time of hydrodynamic evolution with AdS/CFT duality and Bjorken scaling. We use correlation function method ... More

Torsion exceptional sheaves on weak del Pezzo surfaces of Type AMay 04 2016Jun 22 2016We investigate torsion exceptional sheaves on a weak del Pezzo surface of degree greater than two whose anticanonical model has at most $A_n$-singularities. We show that every torsion exceptional sheaf can be obtained from a line bundle on a $(-1)$-curve ... More

Enumeration of graphs with a heavy-tailed degree sequenceApr 04 2014Jul 20 2016In this paper, we asymptotically enumerate graphs with a given degree sequence d=(d_1,...,d_n) satisfying restrictions designed to permit heavy-tailed sequences in the sparse case (i.e. where the average degree is rather small). Our general result requires ... More

Monomorphism operator and perpendicular operatorJan 14 2013For a quiver $Q$, a $k$-algebra $A$, and a full subcategory $\mathcal X$ of $A$-mod, the monomorphism category ${\rm Mon}(Q, \mathcal X)$ is introduced. The main result says that if $T$ is an $A$-module such that there is an exact sequence $0\rightarrow ... More

Iterative Mechanisms for Electricity MarketsAug 31 2016We consider the problem of designing the rules by which market dispatch and payment to participants are gradually adjusted while taking into account network and reliability constraints so as to ensure the market clears with an efficient outcome. Small ... More

Longest-path attacks on complex networksMay 28 2014We investigate the longest-path attacks on complex networks. Specifically, we remove approximately the longest simple path from a network iteratively until there are no paths left in the network. We propose two algorithms, the random augmenting approach ... More

Strong solutions of jump-type stochastic equationsMay 05 2012We establish the existence and uniqueness of strong solutions to some jump-type stochastic equations under non-Lipschitz conditions. The results improve those of Fu and Li (2010) and Li and Mytnik (2011).

There are infinitely many cousin primesOct 16 2005Oct 24 2005We proved that there are infinitely many cousin primes.

There are Infinitely Many Pairs of Twin PrimeOct 09 2005We proved that there are infinitely many pairs of twin prime.

On the two mutually independent factors that determine the convergence of least-squares projection methodJun 03 2014Aug 25 2014This paper investigates the least-squares projection method for bounded linear operators, which provides a natural regularization scheme by projection for many ill-posed problems. Yet, without additional assumptions, the convergence of this approximation ... More

Concentration of Measure for Radial Distributions and Consequences for Statistical ModelingJul 26 2016Sep 11 2016Motivated by problems in high-dimensional statistics such as mixture modeling for classification and clustering, we consider the behavior of radial densities as the dimension increases. We establish a form of concentration of measure, and even a convergence ... More

Energetic Gamma Radiation from Rapidly Rotating Black HolesDec 16 2015Supermassive black holes are believed to be the central power house of active galactic nuclei. Applying the pulsar outer-magnetospheric particle accelerator theory to black-hole magnetospheres, we demonstrate that an electric field is exerted along the ... More

From submodule categories to preprojective algebrasNov 20 2012Feb 27 2014Let S(n) be the category of invariant subspaces of nilpotent operators with nilpotency index at most n. Such submodule categories have been studied already in 1936 by Birkhoff, they have attracted a lot of attention in recent years, for example in connection ... More

Gorenstein-projective and semi-Gorenstein-projective modules. IIMay 10 2019Let k be a field and q a non-zero element of k. In Part I, we have exhibited a 6-dimensional k-algebra A = A(q) and we have shown that if q has infinite multiplicative order, then A has a 3-dimensional local module which is semi-Gorenstein-projective, ... More

Transverse flow induced by inhomogeneous magnetic fields in the Bjorken expansionFeb 16 2016Mar 20 2016We investigate the magnetohydrodynamics in the presence of an external magnetic field following the power-law decay in proper time and having spatial inhomogeneity characterized by a Gaussian distribution in one of transverse coordinates under the Bjorken ... More

Phase Separation in Bose-Fermi-Fermi Mixtures as a Probe of Fermi SuperfluidityApr 17 2008Jun 19 2008We study the phase diagram of a mixture of Bose-Einstein condensate and a two-component Fermi gas. In particular, we identify the regime where the homogeneous system becomes unstable against phase separation. We show that, under proper conditions, the ... More

UDFNet: Unsupervised Disparity Fusion with Adversarial NetworksApr 22 2019Existing disparity fusion methods based on deep learning achieve state-of-the-art performance, but they require ground truth disparity data to train. As far as I know, this is the first time an unsupervised disparity fusion not using ground truth disparity ... More

A Polynomial time Algorithm for Hamilton Cycle and Its detailed proofApr 12 2010Aug 29 2016Popular algorithms to find a Hamilton circle in an undirected graph are generally based on the Rotation-Extension method developed by Posa. However, due to the deficiencies of Posa's method, such algorithms are only efficient for graphs that are either ... More

Higher Groupoid Actions, Bibundles, and DifferentiationDec 14 2015In this thesis, we employ simplicial methods to study actions, principal bundles, and bibundles of higher groupoids. Roughly, we use Kan fibrations to model actions of higher groupoids, we use pairs of a Kan fibration and a special acyclic fibration to ... More

Random Walks on Dicyclic GroupMar 16 2009This paper works out the rate of convergence of two "natural" random walks on the dicyclic group.

Quantum-State Purity of Heralded Single Photons Produced from Frequency-Anti-Correlated BiphotonsJul 13 2015Sep 15 2015We analyze the quantum-state purity of heralded single photons produced from frequency-anti-correlated biphotons. We find that the quantum-state purity in time-frequency domain depends strongly on the response time uncertainty of the trigger-photon detector ... More

Favard, Baxter, Geronimus, Rakhmanov, Szegö and the strong Szegö theorems for orthogonal trigonometric polynomialsJul 23 2008In this paper, we obtain some analogs of Favard, Baxter, Geronimus, Rakhmanov, Szeg\"o and the strong Szeg\"o theorems appeared in the theory of orthogonal polynomials on the unit circle (OPUC) for orthogonal trigonometric polynomials (OTP). The key tool ... More

Two spectral methods for 2D quasi-periodic scattering problemsJul 06 2015Jul 12 2015We consider the 2D quasi-periodic scattering problem in optics, which has been modelled by a boundary value problem governed by Helmholtz equation with transparent boundary conditions. A spectral collocation method and a tensor product spectral method ... More

On Graph Isomorphism ProblemOct 26 2017Let $G$ and $H$ be two simple graphs. A bijection $\phi:V(G)\rightarrow V(H)$ is called an isomorphism between $G$ and $H$ if $(\phi v_i)(\phi v_j)\in E(H)$ $\Leftrightarrow$ $v_i v_j\in E(G)$, $\forall v_i,v_j \in V(G)$. In the case that $G = H$, we ... More

On the Automorphism Group of a GraphJul 02 2016An automorphism of a graph $G$ with $n$ vertices is a bijective map $\phi$ from $V(G)$ to itself such that $\phi(v_i)\phi(v_j)\in E(G)$ $\Leftrightarrow$ $v_i v_j\in E(G)$ for any two vertices $v_i$ and $v_j$ of $G$. Denote by $\mathfrak{G}$ the group ... More

A New Approach to Constrain Black Hole Spins in Active Galaxies Using Optical Reverberation MappingAug 11 2014A tight relation between the size of the broad-line region (BLR) and optical luminosity has been established in about 50 active galactic nuclei studied through reverberation mapping of the broad Hbeta emission line. The R_blr-L relation arises from simple ... More

A Bayesian Approach to Estimate the Size and Structure of the Broad-line Region in Active Galactic Nuclei Using Reverberation Mapping DataOct 15 2013Jan 06 2014This is the first paper in a series devoted to systematic study of the size and structure of the broad-line region (BLR) in active galactic nuclei (AGNs) using reverberation mapping (RM) data. We employ a recently developed Bayesian approach that statistically ... More

Differential Interferometric Signatures of Close Binaries of Supermassive Black Holes in Active Galactic NucleiMar 19 2019Jul 02 2019In the present paper, we explore opportunities of applying the GRAVITY at the Very Large Telescope Interferometry (VLTI) with unprecedented spatial resolution to identify close binaries of supermassive black holes (CB-SMBHs) in active galactic nuclei ... More

Large Spin Pumping from Epitaxial Y3Fe5O12 Thin Films to Pt and W LayersJul 03 2013Epitaxial Y3Fe5O12 thin films have been deposited by off-axis sputtering, which exhibit excellent crystalline quality, enabling observation of large spin pumping signals in Pt/Y3Fe5O12 and W/Y3Fe5O12 bilayers driven by cavity ferromagnetic resonance. ... More

Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. V. A New Size-Luminosity Scaling Relation for the Broad-Line RegionApr 21 2016This paper reports results of the third-year campaign of monitoring super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs) between 2014-2015. Ten new targets were selected from quasar sample of Sloan Digital Sky Survey ... More

Cooling a Mechanical Resonator to Quantum Regime by heating itMar 18 2016Apr 18 2016We consider a mechanical resonator made of diamond, which contains a nitrogen-vacancy center (NV center) locating at the end of the oscillator. A second order magnetic gradient is applied and inducing coupling between mechanical modes and the NV center. ... More

Intervening BLR Clouds' Effects on Optical/UV SpectrumMay 25 2012Recent x-ray observations of Mrk 766 suggest that broad emission line region clouds cross our line of sight and produce variable x-ray absorption. Here we investigate what optical/ultraviolet spectroscopic features would be produced by such "Intervening ... More

The Very Large Telescope Interferometric Signals of Close Binaries of Supermassive Black Holes in Active Galactic NucleiMar 19 2019In the present paper, we explore to apply the GRAVITY at The Very Large Telescope Interferometry (VLTI) with unprecedented spatial resolution to identify close binaries of supermassive black holes (CB-SMBHs) in active galactic nuclei (AGNs). Each SMBH ... More

The Very Large Telescope Interferometric Signals of Close Binaries of Supermassive Black Holes in Active Galactic NucleiMar 19 2019Mar 28 2019In the present paper, we explore to apply the GRAVITY at The Very Large Telescope Interferometry (VLTI) with unprecedented spatial resolution to identify close binaries of supermassive black holes (CB-SMBHs) in active galactic nuclei (AGNs). Each SMBH ... More

Narrow-line Seyfert 1 galaxies in the context of the Quasar Main SequenceJun 18 2018Narrow-line Seyfert 1 galaxies are defined on the basis of their line widths, and they are generally considered to be high Eddington ratio sources. But in the context of the Quasar Main Sequence, high Eddington rate sources are those which have weak [O ... More

The Fundamental Plane of the Broad-line Region in Active Galactic NucleiJan 07 2016Jan 08 2016Broad emission lines in active galactic nuclei (AGNs) mainly arise from gas photoionized by continuum radiation from an accretion disk around a central black hole. The shape of the broad-line profile, described by ${\cal D}_{_{\rm H\beta}}={\rm FWHM}/\sigma_{_{\rm ... More

Cooling a Mechanical Resonator to Quantum Regime by heating itMar 18 2016Nov 04 2016We consider a mechanical resonator made of diamond, which contains a nitrogen-vacancy center (NV center) locating at the end of the oscillator. A second order magnetic gradient is applied and inducing coupling between mechanical modes and the NV center. ... More

A Possible ~20-Year Periodicity in Long-term Optical Photometric and Spectral Variations of the Nearby Radio-Quiet Active Galactic Nucleus Ark 120May 22 2017Mar 13 2019We study the long-term variability in the optical monitoring database of Ark 120, a nearby radio-quiet active galactic nucleus (AGN) at a distance of 143 Mpc (z=0.03271). We compiled the historical archival photometric and spectroscopic data since 1974 ... More

Scaling of spin Hall angle in 3d, 4d and 5d metals from Y3Fe5O12/metal spin pumpingJul 10 2013Jan 16 2014Pure spin currents generated by spin pumping in ferromagnet/nonmagnet (FM/NM) bilayers produce inverse spin Hall effect (ISHE) voltages in the NM, from which spin pumping and transport characteristics of the NM can be extracted. Due to its exceptionally ... More

Metal-Silicene Interaction Studied by Scanning Tunneling MicroscopyJul 08 2015Ag atoms have been deposited on 3x3 silicene and R3xR3 silicene films by molecular beam epitaxy method in ultrahigh vacuum. Using scanning tunneling microscopy and Raman spectroscopy, we found that Ag atoms do not form chemical bonds with both 3x3 silicene ... More

A Bayesian Method for the Intercalibration of Spectra in Reverberation MappingApr 09 2014Flux calibration of spectra in reverberation mapping (RM) is most often performed by assuming the flux constancy of some specified narrow emission lines, which stem from an extended region that is sometimes partially spatially resolved, in contrast to ... More

Serious Game for Human Environmental Consciousness Education in Residents Daily LifeMar 20 2015It has been challenging to find ways to educate people to have better environmental consciousness. In some cases, people do not know what the right behaviors are to protect the environment. Game engine has been used in the AEC industry for visualization. ... More

An Explicit Formula for Likelihood Function for Gaussian Vector Autoregressive Moving-Average Model Conditioned on Initial Observables with Application to Model CalibrationApr 29 2016We derive an explicit formula for likelihood function for Gaussian VARMA model conditioned on initial observables where the moving-average (MA) coefficients are scalar. For fixed MA coefficients the likelihood function is optimized in the autoregressive ... More

Higher order Poisson Kernels and $L^p$ polyharmonic boundary value problems in Lipschitz domainsMar 04 2015Mar 21 2015In this article, we introduce higher order conjugate Poisson and Poisson kernels, which are higher order analogues of the classical conjugate Poisson and Poisson kernels, as well as the polyharmonic fundamental solutions, and define multi-layer potentials ... More

A Polynomial time Algorithm for Hamilton Cycle and Its detailed proofApr 12 2010Nov 10 2016Popular algorithms to find a Hamilton circle in an undirected graph are generally based on the Rotation-Extension method developed by Posa. However, due to the deficiencies of Posa's method, such algorithms are only efficient for graphs that are either ... More

Opaque Response Generation Enabling Automatic Creation of Virtual Services for Service VirtualisationAug 17 2016Service virtualisation is a method to create virtual service models that can mimic interaction behaviors between a system under test and the target system. With service virtualisation, the development team can get access to the production-like conditions ... More

Asymptotic behavior of positive solutions to a degenerate elliptic equation in the upper half space with a nonlinear boundary conditionApr 16 2015We consider positive solutions of the problem \begin{equation} \left\{\begin{array}{l}-\mbox{div}(x_{n}^{a}\nabla u)=0\qquad \mbox{in}\;\;\mathbb{R}_+^n,\\ \frac{\partial u}{\partial \nu^a}=u^{q} \qquad \mbox{on}\;\;\partial \mathbb{R}_+^n,\\ \end{array} ... More

Finite dimensional algebras and cellular systemsDec 08 1999We introduce the notion of a cellular system in order to deal with quasi-hereditary algebras. We shall prove that a necessary and sufficient condition for an algebra to be quasi-hereditary is the existence of a full divisible cellular system. As a further ... More

Robust Mechanisms Under Common ValuationMar 20 2016Nov 19 2016We study robust mechanisms to sell a common-value good. We assume that the mechanism designer knows the prior distribution of the buyers' common value but is unsure of the buyers' information structure about the common value. We use linear programming ... More

Negative frequency communicationDec 07 2010Sep 26 2011Spectrum is the most valuable resource in communication system, but unfortunately, so far, a half of the spectrum has been wasted. In this paper, we will see that the negative frequency not only has a physical meaning but also can be used in communication. ... More

On the canonical maps of nonsingular threefolds of general typeDec 21 2016Dec 28 2016Let $S$ be a nonsingular minimal complex projective surface of general type and the canonical map of $S$ is generically finite. Beauville showed that the geometric genus of the image of the canonical map is vanishing or equals the geometric genus of $S$ ... More

Smooth solution to higher dimensional complex Plateau problemDec 07 2017Dec 14 2017Let $X$ be a compact connected strongly pseudoconvex $CR$ manifold of real dimension $2n-1$ in $\mathbb{C}^{N}$. For $n\ge 3$, Yau solved the complex Plateau problem of hypersurface type by checking a bunch of Kohn-Rossi cohomology groups in 1981. In ... More

On well-conditioned spectral collocation and spectral methods by the integral reformulationNov 04 2015Well-conditioned spectral collocation and spectral methods have recently been proposed to solve differential equations. In this paper, we revisit the well-conditioned spectral collocation methods proposed in [T.~A. Driscoll, {\it J. Comput. Phys.}, 229 ... More

Preconditioning rectangular spectral collocationOct 01 2015Oct 21 2015Rectangular spectral collocation (RSC) methods have recently been proposed to solve linear and nonlinear differential equations with general boundary conditions and/or other constraints. The involved linear systems in RSC become extremely ill-conditioned ... More

Method Study on the 3x+1 ProblemMay 04 2012The 3x+1 problem is one of the most classical problems in computer science, related to many fields. As it is thought by scientists a highly hard problem, resolving it successfully not only can improve the research in many relating fields, but also be ... More

QCD Factorization and Rare B Meson DecaysAug 29 2005Aug 30 2005Some recent progress in China in the study of charmless B decays with QCD factorization is reviewed. Chirally enhanced power corrections and infrared divergence problem are stressed.

Contributions to Persistence TheoryOct 11 2012Apr 20 2014This paper provides a method to calculate the bar codes of a PCD (point cloud data) with real coefficients in Section 3. With Dan Burghelea and Tamal Dey we developed a persistence theory which involves level sets discussed in Section 4. This paper is ... More

The Torsion Generating Set Of The Extended Mapping Class Groups In Low Genus CasesJan 05 2019We prove that for genus $g=3,4$, the extended mapping class group $\text{Mod}^{\pm}(S_g)$ can be generated by two elements of finite orders. But for $g=1$, $\text{Mod}^{\pm}(S_1)$ cannot be generated by two elements of finite orders.

$W^{2,p}$-solutions of parabolic SPDEs in general domainsMay 17 2018The Dirichlet problem for a class of stochastic partial differential equations is studied in Sobolev spaces. The existence and uniqueness result is proved under certain compatibility conditions that ensure the finiteness of $L^{p}(\Omega\times(0,T),W^{2,p}(G))$-norms ... More

On the Complexity of Deciding Degeneracy in GamesMay 19 2009We show that it is NP-Complete to decide whether a bimatrix game is degenerate and it is Co-NP-Complete to decide whether a bimatrix game is nondegenerate.

Any admissible harmonic Ritz value set is possible for prescribed GMRES residual normsApr 23 2016We show that any admissible harmonic Ritz value set is possible for prescribed GMRES residual norms, which is a complement for the results in [Duintjer Tebbens and Meurant, {\it SIAM J. Matrix Anal. Appl.}, 33 (2012), no. 3, pp. 958--978].

Semi-supervised learning of local structured output predictorsApr 11 2016In this paper, we study the problem of semi-supervised structured output prediction, which aims to learn predictors for structured outputs, such as sequences, tree nodes, vectors, etc., from a set of data points of both input-output pairs and single inputs ... More