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Multivariate statistical modelling of future marine stormsMar 13 2019Extreme events, such as wave-storms, need to be characterized for coastal infrastructure design purposes. Such description should contain information on both the univariate behaviour and the joint-dependence of storm-variables. These two aspects have ... More

A simple finite element method for the Stokes equationsOct 17 2016The goal of this paper is to introduce a simple finite element method to solve the Stokes and the Navier-Stokes equations. This method is in primal velocity-pressure formulation and is so simple such that both velocity and pressure are approximated by ... More

Accurate and efficient computation of the Kohn-Sham orbital kinetic energy density in the full-potential linearized augmented plane wave methodJan 07 2015The Kohn-Sham orbital kinetic energy density $\tau_\sigma(\vec{r}) = \sum_{i} w_{i\sigma} \big|\nabla \psi_{i\sigma}(\vec{r}) \big|^2$ is one fundamental quantity for constructing meta-generalized gradient approximations (meta-GGA) for use by density ... More

f-Biharmonic maps and f-biharmonic submanifolds IIApr 30 2016We continue our study [Ou4] of f-biharmonic maps and f-biharmonic submanifolds by exploring the applications of f-biharmonic maps and the relationships among biharmonicity, f-biharmonicity and conformality of maps between Riemannian manifolds. We are ... More

On f-biharmonic maps and f-biharmonic submanifoldsJun 15 2013f-Biharmonic maps are the extrema of the f-bienergy functional. f-biharmonic submanifolds are submanifolds whose defining isometric immersions are f-biharmonic maps. In this paper, we prove that an f-biharmonic map from a compact Riemannian manifold into ... More

On f-harmonic morphisms between Riemannian manifoldsMar 29 2011f-Harmonic maps were first introduced and studied by Lichnerowicz in \cite{Li} (see also Section 10.20 in Eells-Lemaire's report \cite{EL}). In this paper, we study a subclass of f-harmonic maps called f-harmonic morphisms which pull back local harmonic ... More

Quadratic harmonic morphisms and O-systemsNov 03 1995We introduce O-systems (Definition \ref{DO}) of orthogonal transformations of ${\Bbb R}^{m}$, and establish $1-1$ correspondences both between equivalence classes of Clifford systems and that of O-systems, and between O-systems and orthogonal multiplications ... More

Some constructions of biharmonic maps and Chen's conjecture on biharmonic hypersurfacesDec 06 2009Aug 13 2018We give several construction methods and use them to produce many examples of proper biharmonic maps including biharmonic tori of any dimension in Euclidean spheres (Theorem 2.2, Corollaries 2.3, 2.4, and 2.6), biharmonic maps between spheres (Theorem ... More

Complete lifts of harmonic maps and morphisms between Euclidean spacesNov 07 1995We introduce the complete lifts of maps between (real and complex) Euclidean spaces and study their properties concerning holomorphicity, harmonicity and horizontal weakly conformality. As applications, we are able to use this concept to characterize ... More

Some recent progress of biharmonic submanifoldsNov 29 2015In this note, we give a brief survey on some recent developments of biharmonic submanifolds. After reviewing some recent progress on Chen's biharmonic conjecture, the Generalized Chen's conjecture on biharmonic submanifolds of non-positively curved manifolds, ... More

Essential norms of Volterra-type operators between~$Zygmund$~ type spacesJun 24 2016~In this paper, we investigate the boundedness of some Volterra-type operators between ~$Zygmund$~ type spaces. Then, we give the essential norms of such operators in terms of ~$g,\varphi$, their derivatives and the n-th power ~$\varphi^n$ of ~$\varphi$. ... More

Biharmonic conformal immersions into 3-dimensional manifoldsSep 10 2012Motivated by the beautiful theory and the rich applications of harmonic conformal immersions and conformal immersions of constant mean curvature (CMC) surfaces, we study biharmonic conformal immersions of surfaces into a generic 3-manifold. We first derive ... More

Biharmonic hypersurfaces in Riemannian manifoldsJan 12 2009Dec 09 2009We study biharmonic hypersurfaces in a generic Riemannian manifold. We first derive an invariant equation for such hypersurfaces generalizing the biharmonic hypersurface equation in space forms studied in \cite{Ji2}, \cite{CH}, \cite{CMO1}, \cite{CMO2}. ... More

On conformal biharmonic immersionsAug 17 2008This paper studies conformal biharmonic immersions. We first study the transformations of Jacobi operator and the bitension field under conformal change of metrics. We then obtain an invariant equation for a conformal biharmonic immersion of a surface ... More

Confronting Four Zero Neutrino Yukawa Textures with $N_2^{}$-dominated LeptogenesisFeb 13 2015Sep 17 2015We consider a restricted Type-I seesaw scenario with four texture zeros in the neutrino Yukawa matrix, in the weak basis where both the charged-lepton Yukawa matrix and the Majorana mass matrix for right-handed neutrinos are diagonal and real. Inspired ... More

Bayesian Optimal Sequential Multi-Hypothesis Testing in Exponential FamiliesJun 30 2015Jan 26 2017Bayesian sequential testing of multiple simple hypotheses is a classical sequential decision problem. However, the optimal policy is computationally intractable in general, as the posterior probability space is exponentially increasing in the number of ... More

Quantum Adiabatic Doping with Incommensurate Optical LatticesApr 23 2019Quantum simulations of Fermi-Hubbard models have been attracting considerable efforts in the optical lattice research, with the ultracold anti-ferromagnetic atomic phase reached at half filling in recent years. An unresolved issue is to dope the system ... More

Generalized harmonic morphisms and horizontally weakly conformal biharmonic mapsDec 10 2017Harmonic morphisms are maps between Riemannian manifolds that pull back harmonic functions to harmonic functions. These maps are characterized as horizontally weakly conformal harmonic maps and they have many interesting links and applications to several ... More

Biharmonic maps in two dimensionsAug 04 2010Biharmonic maps between surfaces are studied in this paper. We compute the bitension field of a map between surfaces with conformal metrics in complex coordinates. As applications, we show that a linear map from Euclidean plane into $(\mathbb{R}^2, \sigma^2dwd\bar ... More

On the generalized Chen's conjecture on biharmonic submanifoldsJun 09 2010May 02 2014The generalized Chen's conjecture on biharmonic submanifolds asserts that any biharmonic submanifold of a non-positively curved manifold is minimal (see e.g., [CMO1], [MO], [BMO1], [BMO2], [BMO3], [Ba1], [Ba2], [Ou1], [Ou2], [IIU]). In this paper, we ... More

Horizontally homothetic submersions and nonnegative curvatureFeb 01 2006Feb 07 2006We show that any horizontally homothetic submersion from a compact manifold of nonnegative sectional curvature is a Riemannian submersion.

Some remarks on bi-f-harmonic maps and f-biharmonic mapsAug 07 2018In this paper, we prove that the class of bi-f-harmonic maps and that of f-biharmonic maps from a conformal manifold of dimension not equal to 2 are the same (Theorem 1.1). We also give several results on nonexistence of proper bi-f-harmonic maps and ... More

Some classifications of biharmonic hypersurfaces with constant scalar curvatureAug 28 2017We give some classifications of biharmonic hypersurfaces with constant scalar curvature. These include biharmonic Einstein hypersurfaces in space forms, compact biharmonic hypersurfaces with constant scalar curvature in a sphere, and some complete biharmonic ... More

Internal Variations in Empirical Oxygen Abundances for Giant HII Regions in the Galaxy NGC 2403Jan 23 2018Jan 31 2018This paper presents a spectroscopic investigation of 11 HII regions in the nearby galaxy NGC 2403. The HII regions are observed with a long-slit spectrograph mounted on the 2.16 m telescope at XingLong station of National Astronomical Observatories of ... More

Characterizing Ultraviolet and Infrared Observational Properties for Galaxies. II. Features of Attenuation LawJun 16 2014Jun 17 2014Variations in the attenuation law have a significant impact on observed spectral energy distributions for galaxies. As one important observational property for galaxies at ultraviolet and infrared wavelength bands, the correlation between infrared-to-ultraviolet ... More

Gravitational Lensing Analyzed by Graded Refractive Index of VacuumNov 05 2007Feb 13 2008We found strong similarities between the gravitational lensing and the conventional optical lensing. The similarities imply a graded refractive index description of the light deflection in gravitational field. We got a general approach to this refractive ... More

The Deviation of the Vacuum Refractive Index Induced by a Static Gravitational FieldApr 10 2007We analyzed the influence of static gravitational field on the vacuum and proposed the concept of inhomogeneous vacuum. According to the observational result of the light deflection in solar gravitational field as well as the corresponding Fermat's principle ... More

Biharmonic submanifolds of pseudo-Riemannian manifoldsDec 08 2015In this paper, we derived biharmonic equations for pseudo-Riemannian submanifolds of pseudo-Riemannian manifolds which includes the biharmonic equations for submanifolds of Riemannian manifolds as a special case. As applications, we proved that a pseudo-umbilical ... More

Biharmonic hypersurfaces in a conformally flat spaceApr 25 2012Biharmonic hypersurfaces in a generic conformally flat space are studied in this paper. The equation of such hypersurfaces is derived and is used to determine the conformally flat metric $f^{-2}\delta_{ij}$ on the Euclidean space $\mathbb{R}^{m+1}$ so ... More

Biharmonic conformal maps in dimension four and equations of Yamabe-typeJul 11 2017We prove that the problem of constructing biharmonic conformal maps on a $4$-dimensional Einstein manifold reduces to a Yamabe-type equation. This allows us to construct an infinite family of examples on the Euclidean 4-sphere. In addition, we characterize ... More

The braided monoidal structures on a class of linear Gr-categoriesJun 23 2012May 16 2014A linear Gr-category is a category of finite-dimensional vector spaces graded by a finite group together with natural tensor product. We classify the braided monoidal structures of a class of linear Gr-categories via explicit computations of the 3-cocycles ... More

Biharmonic Riemannian submersionsMay 12 2018In this paper, we study biharmonic Riemannian submersions. We first derive bitension field of a general Riemannian submersion, we then use it to obtain biharmonic equations for Riemannian submersions with $1$-dimensional fibers and Riemannian submersions ... More

The Auslander-Reiten formula for complexes of modulesDec 04 2004Dec 29 2004An Auslander-Reiten formula for complexes of modules is presented. This formula contains as a special case the classical Auslander Reiten formula. The Auslander-Reiten translate of a complex is described explicitly, and various applications are discussed. ... More

Electroweak Vacuum Stability and Diphoton Excess at 750 GeVDec 24 2015Apr 28 2016Recently, both ATLAS and CMS collaborations at the CERN Large Hadron Collider (LHC) have announced their observations of an excess of diphoton events around the invariant mass of $750~{\rm GeV}$ with a local significance of $3.6\sigma$ and $2.6\sigma$, ... More

Relic Right-handed Dirac Neutrinos and Implications for Detection of Cosmic Neutrino BackgroundSep 08 2015Dec 25 2015It remains to be determined experimentally if massive neutrinos are Majorana or Dirac particles. In this connection, it has been recently suggested that the detection of cosmic neutrino background of left-handed neutrinos $\nu^{}_{\rm L}$ and right-handed ... More

Classification of Indecomposable Flows of Signed GraphsDec 03 2011Jun 09 2013An indecomposable flow $f$ on a signed graph $\Sigma$ is a nontrivial integral flow that cannot be decomposed into $f=f_1+f_2$, where $f_1,f_2$ are nontrivial integral flows having the same sign (both $\geq 0$ or both $\leq 0$) at each edge of $\Sigma$. ... More

Rethinking the Form of Latent States in Image CaptioningJul 26 2018RNNs and their variants have been widely adopted for image captioning. In RNNs, the production of a caption is driven by a sequence of latent states. Existing captioning models usually represent latent states as vectors, taking this practice for granted. ... More

Quivers, Quasi-Quantum Groups and Finite Tensor CategoriesJun 18 2009We study finite quasi-quantum groups in their quiver setting developed recently by the first author in arXiv:0902.1620 and arXiv:0903.1472. We obtain a classification of finite-dimensional pointed Majid algebras of finite corepresentation type, or equivalently ... More

Constant mean curvature and totally umbilical biharmonic surfaces in 3-dimensional geometriesJan 17 2011We prove that a totally umbilical biharmonic surface in any $3$-dimensional Riemannian manifold has constant mean curvature. We use this to show that a totally umbilical surface in Thurston's 3-dimensional geometries is proper biharmonic if and only if ... More

Infinity-harmonic maps and morphismsOct 06 2008Jan 15 2011We propose a new notion called \emph{infinity-harmonic maps}between Riemannain manifolds. These are natural generalizations of the well known notion of infinity harmonic functions and are also the limiting case of $p$% -harmonic maps as $p\to \infty $. ... More

Biharmonic Riemannian submersions from 3-manifoldsFeb 24 2010An important theorem about biharmonic submanifolds proved independently by Chen-Ishikawa [CI] and Jiang [Ji] states that an isometric immersion of a surface into 3-dimensional Euclidean space is biharmonic if and only if it is harmonic (i.e, minimal). ... More

$U$ independent eigenstates of Hubbard modelJun 27 2016Two-dimensional Hubbard model is very important in condensed matter physics. However it has not been resolved though it has been proposed for more than 50 years. We give several methods to construct eigenstates of the model that are independent of the ... More

A genuine four-partite entangled stateJan 07 2008In a recent paper, a genuine four-partite entangled state is proposed [Y. Yeo and W. K. Chua, Phys. Rev. Lett. 96, 060502 (2006)], which has been found to have many interesting entanglement properties. We show this state is locally equivalent to some ... More

Theory of cavity ring-up spectroscopyOct 08 2017Cavity ring-up spectroscopy (CRUS) provides an advanced technique to sense ultrafast phenomena, but there is no thorough discussion on its theory. Here we give a detailed theoretical analysis of CRUS with and without modal coupling, and present exact ... More

Classification and nondegeneracy of $SU(n+1)$ Toda system with singular sourcesNov 02 2011We consider the following Toda system \Delta u_i + \D \sum_{j = 1}^n a_{ij}e^{u_j} = 4\pi\gamma_{i}\delta_{0} \text{in}\mathbb R^2, \int_{\mathbb R^2}e^{u_i} dx < \infty, \forall 1\leq i \leq n, where $\gamma_{i} > -1$, $\delta_0$ is Dirac measure at ... More

Commutative Hopf structures over a loopFeb 02 2010Let $k$ be an algebraically closed field of characteristic $p>0$. For a loop $\circlearrowleft$, denote its path coalgebra by $k\circlearrowleft$. In this paper, all the finite-dimensional commutative Hopf algebras over the sub coalgebras of $k\circlearrowleft$ ... More

Approximating the optimal competitive ratio for an ancient online scheduling problemFeb 16 2013We consider the classical online scheduling problem P||C_{max} in which jobs are released over list and provide a nearly optimal online algorithm. More precisely, an online algorithm whose competitive ratio is at most (1+\epsilon) times that of an optimal ... More

A Hybridized Formulation for the Weak Galerkin Mixed Finite Element MethodAug 24 2015This paper presents a hybridized formulation for the weak Galerkin mixed finite element method (WG-MFEM) which was introduced and analyzed for second order elliptic equations. The WG-MFEM method was designed by using discontinuous piecewise polynomials ... More

Weak Galerkin Finite Element Methods for the Biharmonic Equation on Polytopal MeshesMar 05 2013A new weak Galerkin (WG) finite element method is introduced and analyzed in this paper for the biharmonic equation in its primary form. This method is highly robust and flexible in the element construction by using discontinuous piecewise polynomials ... More

A Weak Galerkin Finite Element Method with Polynomial ReductionApr 24 2013The novel idea of weak Galerkin (WG) finite element methods is on the use of weak functions and their weak derivatives defined as distributions. Weak functions and weak derivatives can be approximated by polynomials with various degrees. Different combination ... More

Synthetic spin-orbit coupling in ultracold $Λ$-type atomsJul 23 2012We consider the simulation of non-abelian gauge potentials in ultracold atom systems with atom-field interaction in the $\Lambda$ configuration where two internal states of an atom are coupled to a third common one with a detuning. We find the simulated ... More

Weak Galerkin Finite Element Methods on Polytopal MeshesApr 16 2012Aug 17 2012This paper introduces a new weak Galerkin (WG) finite element method for second order elliptic equations on polytopal meshes. This method, called WG-FEM, is designed by using a discrete weak gradient operator applied to discontinuous piecewise polynomials ... More

On Braided Linear Gr-categoriesOct 06 2013May 16 2014We provide explicit and unified formulae for the normalized 3-cocycles on arbitrary finite abelian groups. As an application, we compute all the braided monoidal structures on linear Gr-categories.

A Stable Numerical Algorithm for the Brinkman Equations by Weak Galerkin Finite Element MethodsDec 08 2013This paper presents a stable numerical algorithm for the Brinkman equations by using weak Galerkin (WG) finite element methods. The Brinkman equations can be viewed mathematically as a combination of the Stokes and Darcy equations which model fluid flow ... More

Some classifications of \infty-Harmonic maps between Riemannian manifoldsOct 30 2007$\infty$-Harmonic maps are a generalization of $\infty$-harmonic functions. They can be viewed as the limiting cases of p-harmonic maps as p goes to infinity. In this paper, we give complete classifications of linear and quadratic $\infty$-harmonic maps ... More

A type III radio burst automatic analysis system and statistic results for a half solar-cycle with the Nançay Decameter Array dataOct 06 2018We design an event recognition-analysis system that can automatically detect solar type III radio burst and can mine information of the burst from the dynamic spectra observed by Nancay Decameter Array (NDA). We investigate the frequency drift rate of ... More

On the classification of quadratic harmonic morphisms between Euclidean spacesNov 03 1995We give a classification of quadratic harmonic morphisms between Euclidean spaces (Theorem 2.4) after proving a Rank Lemma. We also find a correspondence between umbilical (Definition 2.7) quadratic harmonic morphisms and Clifford systems. In the case ... More

Gravitational clustering of cosmic relic neutrinos in the Milky WayDec 04 2017May 09 2018The standard model of cosmology predicts the existence of cosmic neutrino background in the present Universe. To detect cosmic relic neutrinos in the vicinity of the Earth, it is necessary to evaluate the gravitational clustering effects on relic neutrinos ... More

A Computational Study of the Weak Galerkin Method for Second-Order Elliptic EquationsNov 02 2011The weak Galerkin finite element method is a novel numerical method that was first proposed and analyzed by Wang and Ye for general second order elliptic problems on triangular meshes. The goal of this paper is to conduct a computational investigation ... More

A New View of Multi-User Hybrid Massive MIMO: Non-Orthogonal Angle Division Multiple AccessFeb 09 2017Jul 15 2017This paper presents a new view of multi-user (MU) hybrid massive multiple-input and multiple-output (MIMO) systems from array signal processing perspective. We first show that the instantaneous channel vectors corresponding to different users are asymptotically ... More

A C^0-Weak Galerkin Finite Element Method for the Biharmonic EquationDec 02 2012A C^0-weak Galerkin (WG) method is introduced and analyzed for solving the biharmonic equation in 2D and 3D. A weak Laplacian is defined for C^0 functions in the new weak formulation. This WG finite element formulation is symmetric, positive definite ... More

Finite quasi-quantum groups of diagonal typeNov 13 2016Dec 20 2016The goal of the present paper is to classify an interesting class of elementary quasi-Hopf algebras, or equivalently, finite-dimensional pointed Majid algebras. By a Tannaka-Krein type duality, this determines a big class of pointed finite tensor categories. ... More

Band structure reconstruction across nematic order in high quality FeSe single crystal as revealed by optical spectroscopy studyJun 07 2016We perform an in-plane optical spectroscopy measurement on high quality FeSe single crystals grown by a vapor transport technique. Below the structural transition at $T_{\rm s}\sim$90 K, the reflectivity spectrum clearly shows a gradual suppression around ... More

Geodesic Distance Function Learning via Heat Flow on Vector FieldsMay 01 2014May 08 2014Learning a distance function or metric on a given data manifold is of great importance in machine learning and pattern recognition. Many of the previous works first embed the manifold to Euclidean space and then learn the distance function. However, such ... More

Biharmonic and f-biharmonic maps from a 2-sphereJan 14 2015We study biharmonic maps and f-biharmonic maps from a round sphere $(S^2, g_0)$, the latter maps are equivalent to biharmonic maps from Riemann spheres $(S^2, f^{-1}g_0)$. We proved that for rotationally symmetric maps between rotationally symmetric spaces, ... More

Entanglement fidelity of the standard quantum teleportation channelJul 19 2012Jun 24 2013We consider the standard quantum teleportation protocol where a general bipartite state is used as entanglement resource. We use the entanglement fidelity to describe how well the standard quantum teleportation channel transmits quantum entanglement and ... More

Active Object Perceiver: Recognition-guided Policy Learning for Object Searching on Mobile RobotsJul 30 2018We study the problem of learning a navigation policy for a robot to actively search for an object of interest in an indoor environment solely from its visual inputs. While scene-driven visual navigation has been widely studied, prior efforts on learning ... More

Wetting and Diffusion of Water on Pristine and Strained PhosphoreneDec 07 2015Phosphorene, a newly fabricated two-dimensional (2D) nanomaterial, have exhibited promising application prospect in biology. Nonetheless, the wetting and diffusive properties of bio-fluids on phosphorene are still elusive. In this study, using molecular ... More

Topological energy gaps in the [111]-oriented InAs/GaSb and GaSb/InAs core-shell nanowiresMar 03 2016The [111]-oriented InAs/GaSb and GaSb/InAs core-shell nanowires have been studied by the $8\times 8$ Luttinger-Kohn $\vec{k}\cdot\vec{p}$ Hamiltonian to search for non-vanishing fundamental gaps between inverted electron and hole bands. We focus on the ... More

A Vision-Guided Multi-Robot Cooperation Framework for Learning-by-Demonstration and Task ReproductionJun 01 2017This paper presents a vision-based learning-by-demonstration approach to enable robots to learn and complete a manipulation task cooperatively. With this method, a vision system is involved in both the task demonstration and reproduction stages. An expert ... More

Carbon nanotube-copper fibers produced by electrospinning: electrical conductivity measurementsNov 19 2018Recent advances in nanotechnology have provided new materials which have the potential to surpass copper and aluminum alloys in electrical conductivity, weight and ampacity [2-6]. Among these carbon nanotubes (CNTs) stand out due to their remarkable thermal ... More

Finite quasi-quantum groups of rank twoAug 18 2015This is a contribution to the structure theory of finite pointed quasi-quantum groups. We classify all finite-dimensional connected graded pointed Majid algebras of rank two which are not twist equivalent to ordinary pointed Hopf algebras.

A Weak Galerkin Mixed Finite Element Method for Biharmonic EquationsOct 14 2012Dec 04 2012This article introduces and analyzes a weak Galerkin mixed finite element method for solving the biharmonic equation. The weak Galerkin method, first introduced by two of the authors (J. Wang and X. Ye) in an earlier publication for second order elliptic ... More

Rethinking the Smaller-Norm-Less-Informative Assumption in Channel Pruning of Convolution LayersFeb 01 2018Feb 02 2018Model pruning has become a useful technique that improves the computational efficiency of deep learning, making it possible to deploy solutions in resource-limited scenarios. A widely-used practice in relevant work assumes that a smaller-norm parameter ... More

A Weak Galerkin Finite Element Method for the Maxwell EquationsDec 09 2013This paper introduces a numerical scheme for time harmonic Maxwell's equations by using weak Galerkin (WG) finite element methods. The WG finite element method is based on two operators: discrete weak curl and discrete weak gradient, with appropriately ... More

Weak Galerkin Methods for Second Order Elliptic Interface ProblemsJan 31 2012Feb 01 2012Weak Galerkin methods refer to general finite element methods for PDEs in which differential operators are approximated by their weak forms as distributions. Such weak forms give rise to desirable flexibilities in enforcing boundary and interface conditions. ... More

A Numerical Study on the Weak Galerkin Method for the Helmholtz EquationOct 22 2013A weak Galerkin (WG) method is introduced and numerically tested for the Helmholtz equation. This method is flexible by using discontinuous piecewise polynomials and retains the mass conservation property. At the same time, the WG finite element formulation ... More

Biharmonic maps from a 2-sphereOct 02 2013Dec 10 2013Motivated by the rich theory of harmonic maps from a 2-sphere, we study biharmonic maps from a 2-sphere in this paper. We first derive biharmonic equation for rotationally symmetric maps between rotationally symmetric 2-manifolds. We then apply the equation ... More

Biharmonic maps from tori into a 2-sphereJun 18 2014Biharmonic maps are generalizations of harmonic maps. A well-known result of Eells and Wood on harmonic maps between surfaces shows that there exists no harmonic map from a torus into a sphere (whatever the metrics chosen) in the homotopy class of maps ... More

Performance of two-dimensional tidal turbine arrays in free surface flowNov 02 2017Encouraged by recent studies on the performance of tidal turbine arrays, we extend the classical momentum actuator disc theory to include the free surface effects and allow the vertical arrangement of turbines. Most existing literatures concern one dimensional ... More

Examining effect of architectural adjustment on pedestrian crowd flow at bottleneckAug 22 2018Recent advances in bottleneck studies have highlighted that different architectural adjustments at the exit may reduce the probability of clogging at the exit thereby enhancing the outflow of the individuals. However, those studies are mostly limited ... More

The Second Order Linear ModelMar 02 2017Jun 23 2017We study a fundamental class of regression models called the second order linear model (SLM). The SLM extends the linear model to high order functional space and has attracted considerable research interest recently. Yet how to efficiently learn the SLM ... More

Efficient Approximate Solutions to Mutual Information Based Global Feature SelectionJun 23 2017Mutual Information (MI) is often used for feature selection when developing classifier models. Estimating the MI for a subset of features is often intractable. We demonstrate, that under the assumptions of conditional independence, MI between a subset ... More

A linear time algorithm for the next-to-shortest path problem on undirected graphs with nonnegative edge lengthsMar 23 2012For two vertices $s$ and $t$ in a graph $G=(V,E)$, the next-to-shortest path is an $st$-path which length is minimum amongst all $st$-paths strictly longer than the shortest path length. In this paper we show that, when the graph is undirected and all ... More

A Numerical Study on the Weak Galerkin Method for the Helmholtz Equation with Large Wave NumbersNov 02 2011Weak Galerkin (WG) refers to general finite element methods for partial differential equations in which differential operators are approximated by weak forms through the usual integration by parts. In particular, WG methods allow the use of discontinuous ... More

Real-time 3D Tracking of Articulated Tools for Robotic SurgeryMay 11 2016Oct 30 2016In robotic surgery, tool tracking is important for providing safe tool-tissue interaction and facilitating surgical skills assessment. Despite recent advances in tool tracking, existing approaches are faced with major difficulties in real-time tracking ... More

A scheme for tunable quantum phase gate and effective preparation of graph-state entanglementJan 07 2008A scheme is presented for realizing a quantum phase gate with three-level atoms, solid-state qubits--often called artificial atoms, or ions that share a quantum data bus such as a single mode field in cavity QED system or a collective vibrational state ... More

Three body open flavor decays of higher charmonium and bottomoniumNov 22 2018May 02 2019In the present work, we study the OZI-allowed three body open flavor decay properties of higher vector charmonium and bottomonium states with an extended quark pair creation model. For the bottomonium system, we get that (i) the $BB\pi$ and $B^*B^*\pi$ ... More

Physical Folding Codes for ProteinsJan 04 2019Exploring and understanding the protein-folding problem has been a long-standing challenge in molecular biology. Here, using molecular dynamics simulation, we reveal how parallel distributed adjacent planar peptide groups of unfolded proteins fold reproducibly ... More

A Nonparametric Maximum Likelihood Approach for Partially Observed Cured Data with Left Truncation and Right-CensoringAug 31 2016Partially observed cured data occur in the analysis of spontaneous abortion (SAB) in observational studies in pregnancy. In contrast to the traditional cured data, such data has an observable `cured' portion as women who do not abort spontaneously. The ... More

Resolution of Indecomposable Integral Flows on Signed GraphsJan 17 2017It is well known that each nonnegative integral flow on a graph can be decomposed into a sum of nonnegative graphic circuit flows, which cannot be further decomposed into nonnegative integral sub-flows. This is equivalent to saying that the indecomposable ... More

Inverse obstacle scattering for Maxwell's equations in an unbounded structureNov 29 2018This paper is concerned with analysis of electromagnetic wave scattering by an obstacle which is embedded in a two-layered lossy medium separated by an unbounded rough surface. Given a dipole point source, the direct problem is to determine the electromagnetic ... More

On Mixing Supersymmetry and Family Symmetry BreakingsSep 26 2012Mar 11 2013We present a toy model in which the Higgs sector fields transform as non-Abelian representations of a family symmetry group, and consider the possibility that the extra family partners of the Higgs particles act as messengers for both supersymmetry and ... More

CamSwarm: Instantaneous Smartphone Camera Arrays for Collaborative PhotographyJul 04 2015Jul 09 2015Camera arrays (CamArrays) are widely used in commercial filming projects for achieving special visual effects such as bullet time effect, but are very expensive to set up. We propose CamSwarm, a low-cost and lightweight alternative to professional CamArrays ... More

Lower branch coherent states in shear flows: transition and controlMar 07 2007Lower branch coherent states in plane Couette flow have an asymptotic structure that consists of O(1) streaks, $O(R^{-1})$ streamwise rolls and a weak sinusoidal wave that develops a critical layer, for large Reynolds number $R$. Higher harmonics become ... More

Frequency-up conversion and quantum swap gate in an optical cavity with atomic cloudJan 05 2008A scheme is presented for realizing frequency-up conversion and a two-qubit quantum swap gate for intracavity fields. In the scheme, a V-type atomic ensemble prepared in their ground states collectively mediates the interaction between the two cavity ... More

Joint Active User Detection and Channel Estimation in Massive Access Systems Exploiting Reed-Muller SequencesMar 23 2019The requirements to support massive connectivity and low latency in massive Machine Type Communications (mMTC) bring a huge challenge in the design of its random access (RA) procedure, which usually calls for efficient joint active user detection and ... More

The Impact of Confounder Selection in Propensity Scores for Rare Events Data - with Applications to Birth DefectsFeb 22 2017Our work was motivated by a recent study on birth defects of infants born to pregnant women exposed to a certain medication for treating chronic diseases. Outcomes such as birth defects are rare events in the general population, which often translate ... More

Holographic Correlators on Integrable SuperstrataApr 09 2019In this work, we study the $\frac{1}{8}$-BPS heavy-heavy-light-light correlators in the D1D5 CFT and its holographic dual. On the field theory side, we compute the fermionic four-point correlators at the free orbifold point. On the dual gravity side, ... More

Third order Maximum-Principle-Satisfying Direct discontinuous Galerkin methods for time dependent convection diffusion equations on unstructured triangle meshAug 18 2015We develop 3rd order maximum-principle-satisfying direct discontinuous Galerkin methods [8, 9, 19, 21] for convection diffusion equations on unstructured triangular mesh. We carefully calculate the normal derivative numerical flux across element edges ... More