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Results for "Yongjin Sung"

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Snapshot projection optical tomographyJun 11 2019We present a new plenoptic microscopy configuration consisting of an objective lens and a micro-lens array (MLA), which is used as a tube lens. The new system that we named as snapshot projection optical tomography (SPOT) can directly record the projection ... More
Two Symmetric Properties of Mersenne Numbers and Fermat NumbersApr 27 2013May 09 2013Mersenne numbers and Fermat numbers are two hot and difficult issues in number theory. This paper constructs a special group for every positive odd number other than 1, and discovers an algorithm for determining the multiplicative order of 2 modulo q ... More
On a Stochastic Wave Equation Driven by a Non-Gaussian Levy ProcessMay 07 2009This paper investigates a damped stochastic wave equation driven by a non-Gaussian Levy noise. The weak solution is proved to exist and be unique. Moreover we show the existence of a unique invariant measure associated with the transition semigroup under ... More
Hydration of ions in two dimensional waterNov 11 2015We present a 2D lattice model of water to study the effects of ion hydration on the properties of water. We map the water molecules as lattice particles consisting of a single Oxygen at the center of a site and two Hydrogen atoms on each side. The internal ... More
The braidings in the mapping class groups of surfacesMay 08 2012The disjoint union of mapping class groups of surfaces forms a braided monoidal category $\mathcal M$, as the disjoint union of the braid groups $\mathcal B$ does. We give a concrete, and geometric meaning of the braiding $\beta_{r,s}$ in $\M$. Moreover, ... More
On multilinearity and skew-symmetry of certain symbols in motivic cohomology of fieldsJan 09 2008Sep 15 2008The purpose of the present article is to show the multilinearity for symbols in Goodwillie-Lichtenbaum complex in two cases. The first case shown is where the degree is equal to the weight. In this case, the motivic cohomology groups of a field are isomorphic ... More
Triviality of a trace on the space of commuting trace-class self-adjoint operatorsMar 17 2008Mar 26 2008In the present article, we investigate a possibility of a real-valued map on the space of tuples of commuting trace-class self-adjoint operators, which behaves like the usual trace map on the space of trace-class linear operators. It turns out that such ... More
Surgery and equivariant Yamabe invariantApr 18 2006May 12 2006We consider the equivariant Yamabe problem, i.e. the Yamabe problem on the space of G-invariant metrics for a compact Lie group G. The G-Yamabe invariant is analogously defined as the supremum of the constant scalar curvatures of unit volume G-invariant ... More
Syzygies of A Tower of Compact Local Hermitian Symmetric Spaces of Finite TypeJan 30 2019Let $X$ be a $n$ dimensional compact local Hermitian symmetric space of non-compact type and $L=\shO(K_X)\tens\shO(qM)$ be an adjoint line bundle. Let $c>0$ be a constant. Assume the curvature of $M$ is $\ge c\omega$, where $\omega$ is the k\"ahler form ... More
G-monopole classes, Ricci flow, and Yamabe invariants of 4-manifoldsMay 17 2012Mar 13 2013On a smooth closed oriented 4-manifold $M$ with a smooth action by a finite group $G$, we show that a $G$-monopole class gives the $L^2$-estimate of the Ricci curvature of a $G$-invariant Riemannian metric, and derive a topological obstruction to the ... More
T-structure and the Yamabe invariantDec 24 2008Nov 22 2010The Yamabe invariant is an invariant of a closed smooth manifold, which contains information about possible scalar curvature on it. It is well-known that a product manifold T^m\times B where T^m$ is the m-dimensional torus, and B is a closed spin manifold ... More
Connected sums with HP^n or CaP^2 and the Yamabe invariantOct 12 2007Feb 24 2011Let $M$ be a smooth closed $4k$-manifold whose Yamabe invariant $Y(M)$ is nonpositive. We show that $$Y(M\sharp l \Bbb HP^k\sharp m \bar{\Bbb HP^k})=Y(M),$$ where $l,m$ are nonnegative integers, and $\Bbb HP^k$ is the quaternionic projective space. When ... More
Validity condition of the Jarzynski relation for a classical mechanical systemJun 09 2005Oct 05 2005Recently, Jarzynski suggested a striking thermodynamic equation that relates free energy change of a system and work done on the system during arbitrary nonequilibrium processes, which has been believed to hold irrespective of detailed nature of the nonequilibrium ... More
Causal Mediation Analysis Leveraging Multiple Types of Summary Statistics DataJan 24 2019Summary statistics of genome-wide association studies (GWAS) teach causal relationship between millions of genetic markers and tens and thousands of phenotypes. However, underlying biological mechanisms are yet to be elucidated. We can achieve necessary ... More
Keratoconus Recognition Using A Parameter Set Determined from IOP-Matched ScenarioJan 07 2019PURPOSE: Among the current practices for keratoconus recognition using biomechanical parameters from Corvis ST, matching intra-ocular pressure (IOP) is often required to eliminate the biasing influence; as a result, the combined biomechanical parameters ... More
On the nonexistence of Einstein metric on 4-manifoldsSep 29 2008Nov 16 2010By using the gluing formulae of the Seiberg-Witten invariant, we show the nonexistence of Einstein metric on manifolds obtained from a 4-manifold with nontrivial Seiberg-Witten invariant by performing sufficiently many connected sums or appropriate surgeries ... More
G-monopole invariants on some connected sums of 4-manifoldsJun 17 2014On a smooth closed oriented $4$-manifold $M$ with a smooth action of a finite group $G$ on a Spin$^c$ structure, $G$-monopole invariant is defined by "counting" $G$-invariant solutions of Seiberg-Witten equations for any $G$-invariant Riemannian metric ... More
Some refined higher type adjunction inequalities on 4-manifoldsJun 17 2014We further sharpen higher type adjunction inequalities of P. Ozsv\'ath and Z. Szab\'o on a 4-manifold $M$ with a nonzero Seiberg-Witten invariant for a Spin$^c$ structure $\frak{s}$, when an embedded surface $\Sigma\subset M$ satisfies $[\Sigma]\cdot ... More
Probing the Gauge Content of Heavy Resonances with Soft RadiationAug 26 2009The use of energy flow is investigated as a diagnostic tool for determining the color SU(3) representation of new resonances. It is found that the pattern of soft gluon radiation into a rapidity gap depends on color flow in the hard scattering, and reflects ... More
Ricci curvature and monopole classes on 3-manifoldsMar 03 2009May 17 2012We prove an L^2-estimate involving Ricci curvature and a harmonic 1-form on a closed oriented Riemannian 3-manifold admitting a solution of any rescaled Seiberg-Witten equations. We also give a necessary condition to be a monopole class on some special ... More
Surgery, Yamabe invariant, and Seiberg-Witten theoryOct 12 2007Nov 06 2010By using the gluing formula of the Seiberg-Witten invariant, we compute the Yamabe invariant Y(X) of 4-manifolds X obtained by performing surgeries along points, circles or tori on compact Kaehler surfaces. For instance, if M is a compact Kaehler surface ... More
Breakdown of the Jarzynski relation for an adiabatic stretching of an isotropic springOct 05 2005Oct 11 2005We perform a theoretical test of Jarzynski relation for an adiabatic stretching of an isotropic spring, which is an exactly solvable model. It turns out that Jarzynski relation does not hold even when the entire infinite momentum space of the system state ... More
Reply to Note on cond-mat/0510270: Jarzynski equation for adiabatically stretched rotorDec 12 2005Although the analysis in cond-mat/0510270 is correct, this doesn't mean Jarzynski relation holds always for an arbitrary process. There exists a sufficient and necessary condition for Jarzynski relation to hold for an adiabatic parameter switching process. ... More
Non-equilibrium spin polarization effects in spin-orbit coupling system and contacting metallic leadsOct 25 2005Nov 08 2006We study theoretically the current-induced spin polarization effect in a two-terminal mesoscopic structure which is composed of a semiconductor two-dimensional electron gas (2DEG) bar with Rashba spin-orbit (SO) interaction and two attached ideal leads. ... More
Holographic description of large N gauge theoryNov 05 2010Jun 28 2011Based on the earlier work [S.-S. Lee, Nucl. Phys. B 832, 567 (2010)], we derive a holographic dual for the D-dimensional U(N) lattice gauge theory from a first principle construction. The resulting theory is a lattice field theory of closed loops, dubbed ... More
A Competitive Algorithm for Online Multi-Robot Exploration of a Translating PlumeNov 07 2018In this paper, we study the problem of exploring a translating plume with a team of aerial robots. The shape and the size of the plume are unknown to the robots. The objective is to find a tour for each robot such that they collectively explore the plume. ... More
The capacity for the linear time-invariant Gaussian relay channelSep 26 2011In this paper, the Gaussian relay channel with linear time-invariant relay filtering is considered. Based on spectral theory for stationary processes, the maximum achievable rate for this subclass of linear Gaussian relay operation is obtained in finite-letter ... More
Simple proofs for universal binary Hermitian latticesMar 26 2008If a positive definite Hermitian lattice represents all positive integers, we call it universal. Several mathematicians, including the author, found 25 universal binary Hermitian lattices. But their ad hoc proofs are complicated. We give simple and unified ... More
Single Stream Parallelization of Recurrent Neural Networks for Low Power and Fast InferenceMar 30 2018As neural network algorithms show high performance in many applications, their efficient inference on mobile and embedded systems are of great interests. When a single stream recurrent neural network (RNN) is executed for a personal user in embedded systems, ... More
Enhancing Non-Orthogonal Multiple Access By Forming Relaying Broadcast ChannelsOct 26 2015In this paper, using relaying broadcast channels (RBCs) as component channels for non-orthogonal multiple access (NOMA) is proposed to enhance the performance of NOMA in single-input single-output (SISO) cellular downlink systems. To analyze the performance ... More
Character-Level Incremental Speech Recognition with Recurrent Neural NetworksJan 25 2016Jan 28 2016In real-time speech recognition applications, the latency is an important issue. We have developed a character-level incremental speech recognition (ISR) system that responds quickly even during the speech, where the hypotheses are gradually improved ... More
On positiveness and contractiveness of the integral operator arising from the beam deflection problem on elastic foundationAug 21 2014We provide a complete proof that there are no nontrivial eigenvalues of the integral operator $\mathcal{K}_l$ outside the interval $(0,1/k)$. $\mathcal{K}_l$ arises naturally from the deflection problem of a beam with length $l$ resting horizontally on ... More
Dimension-Wise Importance Sampling Weight Clipping for Sample-Efficient Reinforcement LearningMay 07 2019In importance sampling (IS)-based reinforcement learning algorithms such as Proximal Policy Optimization (PPO), IS weights are typically clipped to avoid large variance in learning. However, policy update from clipped statistics induces large bias in ... More
Beam Design and User Scheduling for Non-Orthogonal Multiple Access with Multiple Antennas Based on Pareto-OptimalityMay 19 2017In this paper, an efficient transmit beam design and user scheduling method is proposed for multi-user (MU) multiple-input single-output (MISO) non-orthogonal multiple access (NOMA) downlink, based on Pareto-optimality. The proposed beam design and user ... More
Holomorphic maps between closed SU(l,m)-orbits in GrassmannianSep 06 2018Orbits of $SU(\ell, m)$ in a Grassmannian manifold have homogeneous CR structures. In this paper, we study germs of smooth CR mappings sending a closed orbit of $SU(\ell,m)$ into a closed orbit of $SU(\ell',m')$ in Grassmannian manifolds. We show that ... More
Mechanism behind self-sustained oscillations in direct current glow discharges and dusty plasmasFeb 28 2013Apr 09 2013An alternative explanation to the mechanism behind self-sustained oscillations of ions in direct current (DC) glow discharges is provided. Such description is distinguished from the one provided by the fluid models, where oscillations are attributed to ... More
A Novel Device for Generating Terahertz Radiation PulsesJun 13 2011May 11 2012The dynamics of a core-shell structured ionized particle between two parallel conductor plates, which is biased with a direct current (DC) voltage, have been investigated. It has been found that an ionized particle oscillates rapidly between the DC voltage ... More
Recent Developments in Non-Fermi Liquid TheoryMar 23 2017Non-Fermi liquids arise when metals are subject to singular interactions mediated by soft collective modes. In the absence of well-defined quasiparticle, universal physics of non-Fermi liquids is captured by interacting field theories which replace Landau ... More
Identifying the production process of new physics at colliders; symmetric or asymmetric?Mar 07 2016Aug 23 2016We propose a class of kinematic variables, which is a smooth generalization of min-max type mass variables such as the Cambridge-$M_{T2}$ and $M_2$, for measuring a mass spectrum of intermediate resonances in a semi-invisibly decaying pair production. ... More
1-rigidity of CR submanifolds in spheresJun 08 2005Aug 16 2005We propose a unified computational framework for the problem of deformation and rigidity of submanifolds in a homogeneous space under geometric constraint. A notion of 1-rigidity of a submanifold under admissible deformations is introduced. It measures ... More
Conservation laws for a class of Third order Evolutionary differential systemsSep 15 1999The conservation laws of the third order quasilinear scalar evolution equations are considered via differential system and characteristic cohomology. We find a subspace of 2 forms in the infinite prolonged space in which every conservation law has a unique ... More
Scattering wave function approach to multi-terminal mesoscopic system with spin-orbit couplingMay 13 2006In this paper,we present a detailed formulation to solve the scattering wave function for a multi-terminal mesoscopic system with spin-orbit coupling. In addition to terminal currents, all local quantities can be calculated explicitly by taking proper ... More
Quantum Hall Effects in Monolayer-Bilayer Graphene Planar JunctionsAug 19 2013The Hall resistance of a homogeneous electron system is well known to be anti-symmetric with respect to the magnetic field and the sign of charge carriers. We have observed that such symmetries no longer hold in planar hybrid structures consisting of ... More
Evaluation of central corneal thickness in keratoconus and normal corneas during air puff indentationJan 07 2019Purpose: This study aimed to investigate the actual changes of central corneal thickness (CCT) in keratoconus and normal corneas during air puff indentation, by using corneal visualization Scheimpflug technology (Corvis ST). Methods: A total of 32 keratoconic ... More
Morse functions on the moduli space of $G_2$ structuresOct 04 2002May 04 2003Let $ \mathfrak{M}$ be the moduli space of torsion free $ G_2$ structures on a compact 7-manifold $ M$, and let $ \mathfrak{M}_1 \subset \mathfrak{M}$ be the $ G_2$ structures with volume($M$) $=1$. The cohomology map $ \pi^3: \mathfrak{M} \to H^3(M, ... More
Ring class fields by eta-quotientsApr 12 2014Jul 14 2016We generate ring class fields of imaginary quadratic fields in terms of the special values of certain eta-quotients, which are related to the relative norms of Siegel-Ramachandra invariants. These give us minimal polynomials with relatively small coefficients ... More
Temperature and Polarization Patterns in Anisotropic CosmologiesApr 06 2010Apr 15 2010We study the coherent temperature and polarization patterns produced in homogeneous but anisotropic cosmological models. We show results for all Bianchi types with a Friedman-Robertson-Walker limit (i.e. Types I, V, VII$_{0}$, VII$_{h}$ and IX) to illustrate ... More
State dependent spread of entanglement in relatively local HamiltoniansNov 17 2018Feb 15 2019Relatively local Hamiltonians are a class of background independent non-local Hamiltonians from which local theories emerge within a set of short-range entangled states. The dimension, topology and geometry of the emergent local theory is determined by ... More
Stochastic quantization and holographic Wilsonian renormalization group of free massive fermionFeb 01 2017Jun 05 2018We extend the relation between stochstic quantization and Holographic Wilsonian Renormalization Group to the massive fermion case in Euclidean AdS space. The original suggestion about the explicit relation between the two theories is in arXiv:1209.2242. ... More
Robust Chinese Word Segmentation with Contextualized Word RepresentationsJan 17 2019In recent years, after the neural-network-based method was proposed, the accuracy of the Chinese word segmentation task has made great progress. However, when dealing with out-of-vocabulary words, there is still a large error rate. We used a simple bidirectional ... More
Additive uniqueness of $\mathtt{PRIMES}-1$ for multiplicative functionsAug 10 2017Let $\mathtt{PRIMES}$ be the set of all primes. We show that a multiplicative function which satisfies \[ f(p+q-2) = f(p) + f(q) - f(2) \text{ for }p,q \in \mathtt{PRIMES} \] is one of the following: \begin{enumerate} \item $f$ is the identity function ... More
A New Approach to User Scheduling in Massive Multi-User MIMO Broadcast ChannelsMar 27 2014In this paper, a new user-scheduling-and-beamforming method is proposed for multi-user massive multiple-input multiple-output (massive MIMO) broadcast channels in the context of two-stage beamforming. The key ideas of the proposed scheduling method are ... More
Emergent gravity from relatively local Hamiltonians and a possible resolution of the black hole information puzzleMar 01 2018Oct 07 2018In this paper, we study a possibility where gravity and time emerge from quantum matter. Within the Hilbert space of matter fields defined on a spatial manifold, we consider a sub-Hilbert space spanned by states which are parameterized by spatial metric. ... More
Is repulsive Casimir force physical?Aug 30 2004The Casimir force for charge-neutral, perfect conductors of non-planar geometric configurations have been investigated. The configurations are: (1) the plate-hemisphere, (2) the hemisphere-hemisphere and (3) the spherical shell. The resulting Casimir ... More
Symmetric lens with extended depth of focusNov 27 2008Feb 03 2009The lens surface profile is derived based on the instantaneous focal length versus the lens radius data. The lens design based on instantaneous focal length versus the lens radius data has many useful applications in software assisted image focusing technology. ... More
An inexact Noda iteration for computing the smallest eigenpair of a large irreducible monotone matrixApr 09 2015May 21 2015In this paper, we present an inexact Noda iteration with inner-outer iterations for finding the smallest eigenvalue and the associated eigenvector of an irreducible monotone matrix. The proposed inexact Noda iteration contains two main relaxation steps ... More
Multiplicative functions commutable with sums of squaresAug 29 2016Let $k$ be an integer greater than or equal $4$. We show that if a multiplicative function $f$ satisfies \[ f(x_1^2 + x_2^2 + \dots + x_k^2) = f(x_1)^2 + f(x_2)^2 + \dots + f(x_k)^2 \] for all positive integers $x_i$'s, then $f$ is the identity function. ... More
Scalar Curvature Functions of Almost-Kähler MetricsSep 14 2014Sep 18 2014For a closed smooth manifold $M$ admitting a symplectic structure, we define a smooth topological invariant $Z(M)$ using almost-K\"ahler metrics, i.e. Riemannian metrics compatible with symplectic structures. We also introduce $Z(M, [[\omega]])$ depending ... More
A New Asymptotic Analysis Technique for Diversity Receptions Over Correlated Lognormal Fading ChannelsMay 28 2017Prior asymptotic performance analyses are based on the series expansion of the moment-generating function (MGF) or the probability density function (PDF) of channel coefficients. However, these techniques fail for lognormal fading channels because the ... More
Braids, mapping class groups, and categorical deloopingSep 21 2006May 10 2007Dehn twists around simple closed curves in oriented surfaces satisfy the braid relations. This gives rise to a group theoretic from the braid group to the mapping class group. We prove here that this map is trivial in stable homology with any trivial ... More
Kinetic magnetoelectric effect in a 2D semiconductor strip due to boundary-confinement induced spin-orbit couplingMar 28 2006In a thin strip of a two-dimensional semiconductor electronic system, spin-orbit coupling may be induced near both edges of the strip due to the substantial spatial variation of the confining potential in the boundary regions. In this paper we show that, ... More
Single stream parallelization of generalized LSTM-like RNNs on a GPUMar 10 2015Recurrent neural networks (RNNs) have shown outstanding performance on processing sequence data. However, they suffer from long training time, which demands parallel implementations of the training procedure. Parallelization of the training algorithms ... More
Compact special Legendrian surfaces in $S^5$Nov 27 2002May 04 2003A surface $\Sigma \subset S^5 \subset \mathbb{C}^3$ is called \emph{special Legendrian} if the cone $0 \times \Sigma \subset \mathbb{C}^3$ is special Lagrangian. The purpose of this paper is to propose a general method toward constructing compact special ... More
Stochastic Resonance of a Flexible Chain Crossing over a BarrierNov 15 2009Nov 17 2009We study the stochastic resonance (SR) of a flexible polymer surmounting a bistable-potential barrier. Due to the flexibility that can enhance crossing rate and change chain conformations at the barrier, the SR behaviors manifest many features of an entropic ... More
Quark Helicity and Transversity DistributionsOct 20 2016The quark transversity distribution inside nucleon is less understood than the quark unpolarized and helicity distributions inside nucleon. In particular, it is important to know clearly why the quark helicity and transversity distributions are different. ... More
$k$-additive uniqueness of the set of squares for multiplicative functionsDec 02 2016P. V. Chung showed that there are many multiplicative functions $f$ which satisfy $f(m^2+n^2) = f(m^2)+f(n^2)$ for all positive integers $m$ and $n$. In this article, we show that if more than $2$ squares in the additive condition are involved, then such ... More
Notes on the Generalised Second Law of ThermodynamicsMar 22 1997Several comments are given to previous proofs of the generalised second law of thermodynamics: black hole entropy plus ordinary matter entropy never decreases for a thermally closed system. Arguments in favour of its truism are given in the spirit of ... More
A Quantum Material Model of Static Schwarzschild Black HolesMar 16 1997A quantum-mechanical prescription of static Einstein field equation is proposed in order to construct the matter-metric eigen-states in the interior of a static Schwarzschild black hole where the signature of space-time is chosen as (--++). The spectrum ... More
GM-PHD Filter for Searching and Tracking an Unknown Number of Targets with a Mobile Sensor with Limited FOVDec 23 2018We study the problem of searching for and tracking a collection of moving targets using a robot with a limited Field-Of-View (FOV) sensor. The actual number of targets present in the environment is not known a priori. We propose a search and tracking ... More
Effects of static and temporally fluctuating tensions on semiflexible polymer loopingDec 02 2011Biopolymer looping is a dynamic process that occurs ubiquitously in cells for gene regulation, protein folding, etc. In cellular environments, biopolymers are often subject to tensions which are either static, or temporally fluctuating far away from equilibrium. ... More
A lower bound to the action dimension of a groupMay 21 2004The action dimension of a discrete group G, actdim(G), is defined to be the smallest integer m such that G admits a properly discontinuous action on a contractible m-manifold. If no such m exists, we define actdim(G) = infty. Bestvina, Kapovich, and Kleiner ... More
Casimir Force in Non-Planar Geometric ConfigurationsMay 07 2004Aug 06 2004The Casimir force for charge-neutral, perfect conductors of non-planar geometric configurations have been investigated. The configurations are: (1) the plate-hemisphere, (2) the hemisphere-hemisphere and (3) the spherical shell. The resulting Casimir ... More
Dimension-Wise Importance Sampling Weight Clipping for Sample-Efficient Reinforcement LearningMay 07 2019May 29 2019In importance sampling (IS)-based reinforcement learning algorithms such as Proximal Policy Optimization (PPO), IS weights are typically clipped to avoid large variance in learning. However, policy update from clipped statistics induces large bias in ... More
Counting Rational Points on Kummer surfacesJan 30 2019We consider the problem of counting the number of rational points on the family of Kummer surfaces associated with two non-isogenous elliptic curves. For this two-parameter family we prove Manin's unity, using the presentation of the Kummer surfaces as ... More
Enumeration for the total number of all spanning forests of complete tripartite graph based on the combinatorial decompositionNov 04 2013Mar 25 2014This paper discusses the enumeration for the total number of all rooted spanning forests of the labeled complete tripartite graph. We enumerate the total number by a combinatorial decomposition.
Nucleon Transversity and Hyperon PolarizationAug 09 2016We calculate the transverse polarizations of the produced hyperons in the semi-inclusive deep inelastic scattering of unpolarized lepton beam on transversely polarized nucleon, since these polarizations provide a potential method for extracting the transversity ... More
Transverse Spin Polarization of $τ^-$ in ${\bar{B}}^0\rightarrow D^{+} τ^- {\barν}$ and Charged Higgs BosonApr 27 2015May 06 2015The spin of the $\tau$ lepton in the semiletonic process ${\bar{B}}^0\rightarrow D^{+} \tau^- {\bar{\nu}}$ can be polarized in the direction which is normal to the reaction plane, if the charged Higgs boson exists and its coupling to quarks has a complex ... More
Online Sequence Training of Recurrent Neural Networks with Connectionist Temporal ClassificationNov 21 2015Jan 07 2016Connectionist temporal classification (CTC) based supervised sequence training of recurrent neural networks (RNNs) has shown great success in many machine learning areas including end-to-end speech and handwritten character recognition. For the CTC training, ... More
FPGA Based Implementation of Deep Neural Networks Using On-chip Memory OnlyFeb 04 2016Aug 29 2016Deep neural networks (DNNs) demand a very large amount of computation and weight storage, and thus efficient implementation using special purpose hardware is highly desired. In this work, we have developed an FPGA based fixed-point DNN system using only ... More
Embeddedness of proper minimal submanifolds in homogeneous spacesNov 18 2010We prove the three embeddedness results as follows. $({\rm i})$ Let $\Gamma_{2m+1}$ be a piecewise geodesic Jordan curve with $2m+1$ vertices in $\mathbb{R}^n$, where $m$ is an integer $\geq2$. Then the total curvature of $\Gamma_{2m+1}<2m\pi$. In particular, ... More
On the Pareto-Optimal Beam Structure and Design for Multi-User MIMO Interference ChannelsNov 18 2012In this paper, the Pareto-optimal beam structure for multi-user multiple-input multiple-output (MIMO) interference channels is investigated and a necessary condition for any Pareto-optimal transmit signal covariance matrix is presented for the K-pair ... More
Intrinsic Brightness Temperatures of Compact Radio Jets as a Function of FrequencyDec 10 2014We present results of our investigation of the radio intrinsic brightness temperatures of compact radio jets. The intrinsic brightness temperatures of about 100 compact radio jets at 2, 5, 8, 15, and 86 GHz are estimated based on large VLBI surveys conducted ... More
Peres-Style Recursive AlgorithmsMay 11 2018May 22 2018Peres algorithm applies the famous von Neumann trick recursively to produce unbiased random bits from biased coin tosses. Its recursive nature makes the algorithm simple and elegant, and yet its output rate approaches the information-theoretic upper bound. ... More
Bandwidth Extension on Raw Audio via Generative Adversarial NetworksMar 21 2019Neural network-based methods have recently demonstrated state-of-the-art results on image synthesis and super-resolution tasks, in particular by using variants of generative adversarial networks (GANs) with supervised feature losses. Nevertheless, previous ... More
Prototype for Extended XDB Using WikiNov 24 2012This paper describes a prototype of extended XDB. XDB is an open-source and extensible database architecture developed by National Aeronautics and Space Administration (NASA) to provide integration of heterogeneous and distributed information resources ... More
An Omori-Yau maximum principle for semi-elliptic operators and Liouville-type theoremsNov 15 2011Jun 18 2013We generalize the Omori-Yau almost maximum principle of the Laplace-Beltrami operator on a complete Riemannian manifold $M$ to a second-order linear semi-elliptic operator $L$ with bounded coefficients and no zeroth order term. Using this result, we prove ... More
Physics of self-sustained oscillations in the positive glow coronaMar 28 2012Jul 18 2012The physics of self-sustained oscillations in the phenomenon of positive glow corona is presented. The dynamics of charged-particle oscillation under static electric field has been briefly outlined; and, the resulting self-sustained current oscillations ... More
Charged-particle oscillation in DC voltage biased plane-parallel conductorsJun 28 2011Mar 16 2012The phenomenon of charged-particle oscillation in DC voltage biased plane-parallel conductors is discussed. Traditionally accepted mechanism for explaining the oscillatory behavior of charged particles in such system attributes the phenomenon to a process ... More
Lens design based on instantaneous focal functionFeb 02 2009Feb 04 2009The formula for the lens is derived based on the information of instantaneous focal function. Focal function is an important tool in designing lenses with extended depth of focus (EDoF) because this allows EDoF lens designers to try out various mathematical ... More
Charged particle displayDec 15 2008Aug 17 2009An optical shutter based on charged particles is presented. The output light intensity of the proposed device has an intrinsic dependence on the interparticle spacing between charged particles, which can be controlled by varying voltages applied to the ... More
Energy harvesting by utilization of nanohelicesJan 07 2009Mar 18 2009An energy harvesting device based on nanohelices is presented. The energy harvesting scheme based on nanohelices involves the same rectification circuitry found in many household electronic goods, which converts alternating current (AC) from a wall outlet ... More
Willmore Legendrian surfaces in pseudoconformal 5-sphereJul 03 2007Let $ X: M \hook S^5$ be a compact Legendrian surface in pseudoconformal(CR) 5-sphere. We introduce a pseudoconformally invariant Willmore type second order functional $ \W(X)$, and study its critical points called Willmore Legendrian surfaces. The fifth ... More
COMBINE: a novel drug discovery platform designed to capture insight and experience of usersNov 13 2017The insight and experience gained by a researcher are often lost because the current productive and analytics software are inherently data-centric, disconnected, and scattered. The connected nature of insight and experience can be captured if the applications ... More
The symmetry of Spin^c Dirac spectrums on Riemannian product manifoldsAug 24 2013It is well-known that the spectrum of a $\text{spin}^{\mathbb{C}}$ Dirac operator on a closed Riemannian $\text{spin}^{\mathbb{C}}$ manifold $M^{2k}$ of dimension $2k$ for $k \in \mathbb{N}$ is symmetric. In this article, we prove that over an odd-dimensional ... More
Towards a better understanding of the evolution of Wolf-Rayet stars and Type Ib/Ic supernova progenitorsJun 15 2017Hydrogen-deficient Wolf-Rayet (WR) stars are potential candidates of Type Ib/Ic supernova (SN Ib/Ic) progenitors and their evolution is governed by mass loss. Stellar evolution models with the most popular prescription for WR mass-loss rates given by ... More
Evolutionary Models for Type Ib/c Supernova ProgenitorsApr 06 2015Apr 14 2015Type Ib/c supernovae (SNe Ib/c) mark the deaths of hydrogen-deficient massive stars. The evolutionary scenarios for SNe Ib/c progenitors involve many important physical processes including mass loss by winds and its metallicity dependence, stellar rotation, ... More
Some symmetry properties of spin currents and spin polarizations in multi-terminal mesoscopic spin-orbit coupled systemsOct 28 2007We study theoretically some symmetry properties of spin currents and spin polarizations in multi-terminal mesoscopic spin-orbit coupled systems. Based on a scattering wave function approach, we show rigorously that in the equilibrium state no finite spin ... More
Character-Level Language Modeling with Hierarchical Recurrent Neural NetworksSep 13 2016Recurrent neural network (RNN) based character-level language models (CLMs) are extremely useful for modeling unseen words by nature. However, their performance is generally much worse than the word-level language models (WLMs), since CLMs need to consider ... More