Results for "Taek Jung Kim"

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Calculating magnetic interactions in organic electridesApr 14 2018Jun 10 2018We present our calculation results for organic magnetic electrides. In order to identify the `cavity' electrons, we use maximally-localized Wannier functions and `empty atom' technique. The estimation of magnetic coupling is then performed based on magnetic ... More
Sub-room temperature ferromagnetism and its nature in VSe$_2$ monolayerJul 10 2019Magnetic van der Waals materials provide an ideal platform for exploring two-dimensional magnetism of technological and scientific importance. Among them, 1T-VSe$_2$ has been reported as one of the first room-temperature two-dimensional ferromagnets. ... More
Current-induced domain wall motion in a nanowire with perpendicular magnetic anisotropyApr 24 2008We study theoretically the current-induced magnetic domain wall motion in a metallic nanowire with perpendicular magnetic anisotropy. The anisotropy can reduce the critical current density of the domain wall motion. We explain the reduction mechanism ... More
Reliability and applicability of magnetic force linear response theory: Numerical parameters, predictability, and orbital resolutionOct 20 2017We investigated the reliability and applicability of so-called magnetic force linear response method to calculate spin-spin interaction strengths from first-principles. We examined the dependence on the numerical parameters including the number of basis ... More
Knotted surfaces in 4-manifolds by Knot surgery and StabilizationJan 09 2017Nov 08 2017Given a simply-connected closed 4-manifold $X$ and a smoothly embedded oriented surface $\Sigma$, various constructions based on Fintushel-Stern knot surgery have produced new surfaces in $X$ that are pairwise homeomorphic to $\Sigma$, but not diffeomorphic. ... More
A New Probe of Cosmic Strings at LIGO and Mid-band: Gravitational Lensing FringeOct 09 2018Cosmic strings are important remnants of early-Universe phase transitions. We show that they may be probed in a new way with LIGO and future gravitational-wave (GW) detectors. When the GW from compact binary mergers passes by a cosmic string, it is gravitationally ... More
Super-Gaussian, super-diffusive transport of multi-mode active matterAug 01 2017Living cells exhibit multi-mode transport that switches between an active, self-propelled motion and a seemingly passive, random motion. Cellular decision-making over transport mode switching is a stochastic process that depends on the dynamics of the ... More
Coupling of phonons and spin waves in triangular antiferromagnetApr 26 2007Jul 02 2007We investigate the influence of the spin-phonon coupling in the triangular antiferromagnet where the coupling is of the exchange-striction type. The magnon dispersion is shown to be modified significantly at wave vector (2pi,0) and its symmetry-related ... More
Learning acoustic word embeddings with phonetically associated triplet networkNov 07 2018Nov 28 2018Previous researches on acoustic word embeddings used in query-by-example spoken term detection have shown remarkable performance improvements when using a triplet network. However, the triplet network is trained using only a limited information about ... More
Double point surgery and configurations of surfacesJan 21 2010May 18 2011We introduce a new operation, double point surgery, on immersed surfaces in a 4-manifold, and use it to construct knotted configurations of surfaces in many 4-manifolds. Taking branched covers, we produce smoothly exotic actions of Z/m x Z/n on simply ... More
Broadband wide-angle absorption enhancement due to mode conversion in cold unmagnetized plasmas with periodic density variationsFeb 19 2016We study theoretically the mode conversion and the associated resonant absorption of p-polarized electromagnetic waves into longitudinal plasma oscillations in cold, unmagnetized and stratified plasmas with periodic spatial density variations. We consider ... More
Improved Parameterized Algorithms for Constraint SatisfactionAug 02 2010Oct 14 2011For many constraint satisfaction problems, the algorithm which chooses a random assignment achieves the best possible approximation ratio. For instance, a simple random assignment for {\sc Max-E3-Sat} allows 7/8-approximation and for every $\eps >0$ there ... More
Properly Coloured Cycles and Paths: Results and Open ProblemsMay 26 2008May 31 2008In this paper, we consider a number of results and seven conjectures on properly edge-coloured (PC) paths and cycles in edge-coloured multigraphs. We overview some known results and prove new ones. In particular, we consider a family of transformations ... More
Topological spines of 4-manifoldsMay 09 2019We show that infinitely many of the simply connected 4-manifolds constructed by Levine and Lidman that do not admit PL spines actually admit topological spines.
First-order transitions and thermodynamic properties in the 2D Blume-Capel model: the transfer-matrix method revisitedAug 13 2017Dec 09 2017We investigate the first-order transition in the spin-1 two-dimensional Blume-Capel model in square lattices by revisiting the transfer-matrix method. With large strip widths increased up to the size of 18 sites, we construct the detailed phase coexistence ... More
Supersymmetric polynomials and the center of the walled Brauer algebraAug 26 2015Mar 21 2017We study a commuting family of elements of the walled Brauer algebra $B_{r,s}(\delta)$, called the Jucys-Murphy elements, and show that the supersymmetric polynomials in these elements belong to the center of the walled Brauer algebra. When $B_{r,s}(\delta)$ ... More
Dynamical Renormalization Group Study of a Conserved Surface Growth with Anti-Diffusive and Nonlinear CurrentsSep 17 1996Based on dynamical renormalization group (RG) calculations to the one-loop order, the surface growth described by a nonlinear stochastic conserved growth equation, {\partial h \over \partial t} = \pm \nu_2 \nabla^2 h + \lambda\nabla \cdot (\nabla h)^3 ... More
The Lawrence--Krammer representation is unitaryFeb 21 2002We show that the Lawrence--Krammer representation is unitary. We explicitly present the non-singular matrix representing the sesquilinear pairing invariant under the action. We show that reversing the orientation of a braid is equivalent to the transposition ... More
Superbridge index of composite knotsJan 15 2000Apr 18 2001An upper bound of the superbridge index of the connected sum of two knots is given in terms of the braid index of the summands. Using this upper bound and minimal polygonal presentations, we give an upper bound in terms of the superbridge index and the ... More
Practical biological spread-out Bragg peak design of carbon beamJul 16 2015The carbon beams show more advantages on the biological properties compared with proton beams in radiation therapy. The carbon beam shows high linear energy transfer (LET) to medium and it increases the relative biological effectiveness (RBE). To design ... More
Vector chiral states in low-dimensional quantum spin systemsMay 28 2007Jun 26 2007A class of exact spin ground states with nonzero averages of vector spin chirality, $<\v{S}_i \times \v{S}_j \cdot \hat{z}>$, is presented. It is obtained by applying non-uniform O(2) rotations of spin operators in the XY plane on the SU(2)-invariant ... More
Contact 3-manifolds and Ricci solitonsFeb 27 2012A contact 3-manifold $M$ admitting a transversal Ricci soliton $(g,v,\lambda)$ is either Sasakian or locally isometric to one of the Lie groups SU(2), $SL(2,R)$, E(2), E(1,1) with a left invariant metric.
Enumeration of Fuss-Schröder pathsJan 02 2017In this paper we enumerate the number of $(k, r)$-Fuss-Schr\"{o}der paths of type $\lambda$. Y. Park and S. Kim studied small Schr\"{o}der paths with type $\lambda$. Generalizing the results to small $(k, r)$-Fuss-Schr\"{o}der paths with type $\lambda$, ... More
On tiling the integers with $4$-sets of the same gap sequenceMay 11 2016Partitioning a set into similar, if not, identical, parts is a fundamental research topic in combinatorics. The question of partitioning the integers in various ways has been considered throughout history. Given a set $\{x_1, \ldots, x_n\}$ of integers ... More
Malicious web script-based cyber attack protection technologyFeb 13 2015Recent web-based cyber attacks are evolving into a new form of attacks such as private information theft and DDoS attack exploiting JavaScript within a web page. These attacks can be made just by accessing a web site without distribution of malicious ... More
Pre-Main Sequence Evolutions of Solar Abundance Lowmass StarsFeb 12 2007We present the Pre-Main-Sequence (PMS) evolutionary tracks of stars with 0.0065~5.0Ms. The models were evolved from the PMS stellar birthline to the onset of hydrogen burning in the core. The convective turnover timescales which enables an observational ... More
Low-energy dynamics of the Affleck-Kennedy-Lieb-Tasaki model in the one- and two-triplon basisJun 10 2019The elementary excitation in the antiferromagnetic spin-1 model known as the Affleck-Kennedy-Lieb-Tasaki (AKLT) Hamiltonian has been described alternatively as magnons or kink-like solitons (triplons). The latter, which we call the triplon throughout ... More
On the Anti-Jamming Performance of the NR-DCSK SystemNov 15 2017This paper investigates the anti-jamming performance of the NR-DCSK system. We consider several practical jamming environments including broad-band jamming (BBJ), partial-time jamming (PTJ), tone jamming (TJ) consisting of both single-tone and multi-tone, ... More
Contact Ricci flowApr 11 2011Jan 17 2012We introduce the notion of contact Ricci flow associated with the Reeb vector field. Using it, we give a simple proof of the Poincare conjecture.
Spectral analysis on a phonon spectral function of a solid-state plasma in a doped semiconductorOct 18 2014We report an analysis on a phonon spectral function of a solid-state plasma formed in a doped semiconductor. Real and imaginary parts of phonon propagators are evaluated including carrier screening effects within a random phase approximation, and finite-temperature ... More
Fluorine-induced local magnetic moment in graphene: A hybrid DFT studyApr 02 2013Recent experimental evidence that fluorinated graphene creates local magnetic moments around F adatoms has not been supported by semilocal density-functional theory (DFT) calculations where the adsorption of an isolated F adatom induces no magnetic moment ... More
Recognizing k-equistable graphs in FPT timeMar 03 2015A graph $G = (V,E)$ is called equistable if there exist a positive integer $t$ and a weight function $w : V \to \mathbb{N}$ such that $S \subseteq V$ is a maximal stable set of $G$ if and only if $w(S) = t$. Such a function $w$ is called an equistable ... More
Bidding, Pricing, and User Subscription Dynamics in Asymmetric-valued Korean LTE Spectrum Auction: A Hierarchical Dynamic Game ApproachJul 01 2015The tremendous increase in mobile data traffic coupled with fierce competition in wireless industry brings about spectrum scarcity and bandwidth fragmentation. This inevitably results in asymmetric-valued LTE spectrum allocation that stems from different ... More
Dynamic Heterogeneity in Crossover Spin Facilitated Model of Supercooled Liquid and Fractional Stokes-Einstein RelationOct 21 2015Kinetically constrained models (KCMs) have gained much interest as models that assign the origins of interesting dynamic properties of supercooled liquids to dynamical facilitation mechanisms that have been revealed in many expreiments and numerical simulations. ... More
Symplectic coordinates on $\mathrm{PSL}_3(\mathbb{R})$-Hitchin componentsJan 15 2019Apr 17 2019Goldman parametrizes the $\mathrm{PSL}_3(\mathbb{R})$-Hitchin component of a closed oriented hyperbolic surface of genus $g$ by $16g-16$ parameters. Among them, $10g-10$ coordinates are canonical. We prove that the $\mathrm{PSL}_3(\mathbb{R})$-Hitchin ... More
Dynamic Structures of 2-adic Fibonacci Polynomials IMar 13 2019May 15 2019We prove recurrence relations and modulo periodic properties of multiple derivatives of Fibonacci polynomials. We apply the obtained results to present the dynamic structures of Fibonacci polynomials over the ring of 2-adic integers by investigating minimal ... More
Crystalline topological Dirac semimetal phase in rutile structure $β'$-PtO$_2$Sep 24 2018Jan 17 2019Based on first-principles calculations and symmetry analysis, we propose that a transition metal rutile oxide, in particular $\beta'$-PtO$_2$, can host a three-dimensional topological Dirac semimetal phase. We find that $\beta'$-PtO$_2$ possesses a linked ... More
Statistical properties of chaotic microcavities in small and large opening casesMay 29 2013Apr 02 2019We study the crossover behavior of statistical properties of eigenvalues in a chaotic microcavity with different refractive indices. The level spacing distributions change from Wigner to Poisson distributions as the refractive index of a microcavity decreases. ... More
Physical Layer Security Schemes for Full-Duplex Cooperative Systems: State of the Art and BeyondNov 15 2017Due to the broadcast nature of wireless medium, wireless communication is highly vulnerable to eavesdropping attack. Traditionally, secure wireless data transmission has relied on cryptographic techniques at the network layer which incur high computational ... More
Heterogeneous dynamics and its length scale in simple ionic liquid models: A computational studyMar 09 2016We numerically investigate the dynamic heterogeneity and its length scale found in the coarse-grained ionic liquid model systems. In our ionic liquid model systems, cations are modeled as dimers with positive charge, while anions are modeled as monomers ... More
A Geometric Fractal Growth Model for Scale Free NetworksDec 19 2001We introduce a deterministic model for scale-free networks, whose degree distribution follows a power-law with the exponent $\gamma$. At each time step, each vertex generates its offsprings, whose number is proportional to the degree of that vertex with ... More
Resource Allocation with Reverse Pricing for Communication NetworksApr 24 2015Mar 22 2016Reverse pricing has been recognized as an effective tool to handle demand uncertainty in the travel industry (e.g., airlines and hotels). To investigate its viability for communication networks, we study the practical limitations of (operator-driven) ... More
On Riemannian foliations admitting transversal conformal fieldsOct 18 2018Let $(M,g_M,\mathcal F)$ be a closed, connected Riemannian manifold with a Riemannian foliation $\mathcal F$ of nonzero constant transversal scalar curvature. When $M$ admits a transversal nonisometric conformal field, we find some generalized conditions ... More
Facial structures of lattice path matroid polytopesJan 02 2017A lattice path matroid is a transversal matroid corresponding to a pair of lattice paths on the plane. A matroid base polytope is the polytope whose vertices are the incidence vectors of the bases of the given matroid. In this paper, we study facial structures ... More
Semiparametric Mixed Model for Evaluating Pathway-Environment InteractionJun 13 2012A biological pathway represents a set of genes that serves a particular cellular or a physiological function. The genes within the same pathway are expected to function together and hence may interact with each other. It is also known that many genes, ... More
Water-Filling: An Efficient Algorithm for Digitized Document Shadow RemovalApr 22 2019May 02 2019In this paper, we propose a novel algorithm to rectify illumination of the digitized documents by eliminating shading artifacts. Firstly, a topographic surface of an input digitized document is created using luminance value of each pixel. Then the shading ... More
A Polynomial Kernel for Distance-Hereditary Vertex DeletionOct 23 2016Feb 20 2017A graph is distance-hereditary if for any pair of vertices, their distance in every connected induced subgraph containing both vertices is the same as their distance in the original graph. The Distance-Hereditary Vertex Deletion problem asks, given a ... More
A polynomial kernel for Block Graph DeletionJun 29 2015Jan 14 2016In the Block Graph Deletion problem, we are given a graph $G$ on $n$ vertices and a positive integer $k$, and the objective is to check whether it is possible to delete at most $k$ vertices from $G$ to make it a block graph, i.e., a graph in which each ... More
Slowing down of ring polymer diffusion caused by inter-ring threadingOct 20 2015Diffusion of long ring polymers in a melt is much slower than the reorganization of their internal structures. While direct evidences for entanglements have not been observed in the long ring polymers unlike linear polymer melts, threading between the ... More
CP violating supersymmetric contributions to the electroweak $ρ$ parameterAug 09 2000Effects of CP violation on the supersymmetric electroweak correction to the $\rho$ parameter are investigated. To avoid the EDM constraints, we require that arg$(\mu)<10^{-2}$ and the non-universal trilinear couplings $A_f=(0,0,A_0)$ and also assume that ... More
Type-II Dirac line node in strained Na3NJul 23 2018Dirac line node (DLN) semimetals are a class of topological semimetals that feature band-crossing lines in momentum space. We study the type-I and type-II classification of DLN semimetals by developing a criterion that determines the type using band velocities. ... More
Revitalizing Copybacks in Modern SSDs: Why and HowOct 10 2018For modern flash-based SSDs, the performance overhead of internal data migrations is dominated by the data transfer time, not by the flash program time as in old SSDs. In order to mitigate the performance impact of data migrations, we propose rCopyback, ... More
Band Topology and Linking Structure of Nodal Line Semimetals with Z2 Monopole ChargesMar 30 2018Dec 21 2018We study the band topology and the associated linking structure of topological semimetals with nodal lines carrying $Z_{2}$ monopole charges, which can be realized in three-dimensional systems invariant under the combination of inversion $P$ and time ... More
Sum-Rate Maximizing Cell Association via Dual-ConnectivityMay 12 2015This paper proposes a dual-connectivity (DC) profile allocation algorithm, in which a central macro base station (MBS) is underlaid with randomly scattered small base stations (SBSs), operating on different carrier frequencies. We introduce two dual-connectivity ... More
Spatial Pyramid Encoding with Convex Length Normalization for Text-Independent Speaker VerificationJun 19 2019In this paper, we propose a new pooling method called spatial pyramid encoding (SPE) to generate speaker embeddings for text-independent speaker verification. We first partition the output feature maps from a deep residual network (ResNet) into increasingly ... More
Effect of Long-Range Interactions in the Conserved Kardar-Parisi-Zhang EquationJun 02 1998The conserved Kardar-Parisi-Zhang equation in the presence of long-range nonlinear interactions is studied by the dynamic renormalization group method. The long-range effect produces new fixed points with continuously varying exponents and gives distinct ... More
Mutation invariance of the arc index for some Montesinos knotsApr 06 2017For the alternating knots or links, mutations do not change the arc index. In the case of nonalternating knots, some semi-alternating knots or links have this property. We mainly focus on the problem of mutation invariance of the arc index for nonalternating ... More
CIAO: Cache Interference-Aware Throughput-Oriented Architecture and Scheduling for GPUsMay 20 2018A modern GPU aims to simultaneously execute more warps for higher Thread-Level Parallelism (TLP) and performance. When generating many memory requests, however, warps contend for limited cache space and thrash cache, which in turn severely degrades performance. ... More
Causal Proportional Hazards Estimation with a Binary Instrumental VariableJan 30 2019Instrumental variables (IV) are a useful tool for estimating causal effects in the presence of unmeasured confounding. IV methods are well developed for uncensored outcomes, particularly for structural linear equation models, where simple two-stage estimation ... More
Photometric Transformer Networks and Label Adjustment for Breast Density PredictionMay 08 2019Grading breast density is highly sensitive to normalization settings of digital mammogram as the density is tightly correlated with the distribution of pixel intensity. Also, the grade varies with readers due to uncertain grading criteria. These issues ... More
Statistical Analysis of Some Evolution Equations Driven by Space-only NoiseApr 03 2019We study the statistical properties of stochastic evolution equations driven by space-only noise, either additive or multiplicative. While forward problems, such as existence, uniqueness, and regularity of the solution, for such equations have been studied, ... More
Resource Sharing and Pipelining in Coarse-Grained Reconfigurable Architecture for Domain-Specific OptimizationOct 25 2007Coarse-grained reconfigurable architectures aim to achieve both goals of high performance and flexibility. However, existing reconfigurable array architectures require many resources without considering the specific application domain. Functional resources ... More
Deeply-Recursive Convolutional Network for Image Super-ResolutionNov 14 2015Nov 11 2016We propose an image super-resolution method (SR) using a deeply-recursive convolutional network (DRCN). Our network has a very deep recursive layer (up to 16 recursions). Increasing recursion depth can improve performance without introducing new parameters ... More
Competing Spin Liquid Phases in the S=$\frac{1}{2}$ Heisenberg Model on the Kagome LatticeOct 06 2016Jun 11 2019The properties of ground state of spin-$\frac{1}{2}$ kagome antiferromagnetic Heisenberg (KAFH) model have attracted considerable interest in the past few decades, and recent numerical simulations reported a spin liquid phase. The nature of the spin liquid ... More
Bernoulli-Gaussian Approximate Message-Passing Algorithm for Compressed Sensing with 1D-Finite-Difference SparsityAug 18 2014Sep 04 2015This paper proposes a fast approximate message-passing (AMP) algorithm for solving compressed sensing (CS) recovery problems with 1D-finite-difference sparsity in term of MMSE estimation. The proposed algorithm, named ssAMP-BGFD, is low-computational ... More
Designing Anti-Jamming Receivers for NR-DCSK Systems Utilizing ICA, WPD, and VMD MethodsOct 04 2018In this work, we consider an advanced noise reduction differential chaotic shift keying (NR-DCSK) system in which a single antenna source communicates with a single antenna destination under the attack of a single antenna jammer. We devote our efforts ... More
Zero-line modes at stacking faulted domain walls in multilayer grapheneJul 06 2016Sep 30 2016Rhombohedral multilayer graphene is a physical realization of the chiral two-dimensional electron gas that can host zero-line modes (ZLMs), also known as kink states, when the local ap opened by inversion symmetry breaking potential changes sign in real ... More
Automatic Music Highlight Extraction using Convolutional Recurrent Attention NetworksDec 16 2017Music highlights are valuable contents for music services. Most methods focused on low-level signal features. We propose a method for extracting highlights using high-level features from convolutional recurrent attention networks (CRAN). CRAN utilizes ... More
Effective Approximation of Electromagnetism for Axion Haloscope SearchesOct 04 2018Feb 01 2019We applied an effective approximation into Maxwell's equations with an axion interaction for haloscope searches. A set of Maxwell's equations acquired from this approximation describes just the reacted fields generated by the anomalous interaction. Unlike ... More
X-ray Photoemission Study of MgB2Mar 09 2001Apr 22 2001A c-axis oriented thin film and a high density sintered pellet of MgB2 have been studied by x-ray photoemission spectroscopy, and compared to measurements from MgO and MgF2 single crystals. The as-grown surface has a layer which is Mg-rich and oxidized, ... More
Analysis of multiple exceptional points related to three interacting eigenmodes in a non-Hermitian HamiltonianSep 20 2011Mar 28 2012We have investigated the exceptional points (EPs) which are degeneracies of a non-Hermitian Hamiltonian, in the case that three modes are interacting with each other. Even though the parametric evolution of the modes cannot be uniquely determined when ... More
Data-driven Shoulder Inverse KinematicsNov 17 2016This paper proposes a shoulder inverse kinematics (IK) technique. Shoulder complex is comprised of the sternum, clavicle, ribs, scapula, humerus, and four joints. The shoulder complex shows specific motion pattern, such as Scapulo humeral rhythm. As a ... More
An SEIR Epidemic Model where Empirical Distribution of Incubation Period has Approximated by Coxian DistributionJun 13 2019In this work, we have developed a Coxian distributed SEIR model in incorporating an empirical incubation period since Coxian distribution approximately converges to any distribution. A basic reproduction number is found from the model. An application ... More
Antiferromagnetic Slater Insulator Phase of Na2IrO3Dec 21 2013May 05 2014Using a hybrid density-functional theory (DFT) calculation including spin-orbit coupling (SOC), we predict that the zigzag antiferromagnetic (AFM) ground state of the honeycomb layered compound Na2IrO3 opens the observed insulating gap through a long-range ... More
Vertex Cover Problem Parameterized Above and Below Tight BoundsJul 26 2009Aug 28 2009We study the well-known Vertex Cover problem parameterized above and below tight bounds. We show that two of the parameterizations (both were suggested by Mahajan, Raman and Sikdar, J. Computer and System Sciences, 75(2):137--153, 2009) are fixed-parameter ... More
Holes and a chordal cut in a graphMar 22 2011A set $X$ of vertices of a graph $G$ is called a {\em clique cut} of $G$ if the subgraph of $G$ induced by $X$ is a complete graph and the number of connected components of $G-X$ is greater than that of $G$. A clique cut $X$ of $G$ is called a {\em chordal ... More
The competition number of a graph in which any two holes share at most one edgeFeb 28 2011The competition graph of a digraph D is a (simple undirected) graph which has the same vertex set as D and has an edge between x and y if and only if there exists a vertex v in D such that (x,v) and (y,v) are arcs of D. For any graph G, G together with ... More
Demand Forecasting from Spatiotemporal Data with Graph Networks and Temporal-Guided EmbeddingMay 26 2019Short-term demand forecasting models commonly combine convolutional and recurrent layers to extract complex spatiotemporal patterns in data. Long-term histories are also used to consider periodicity and seasonality patterns as time series data. In this ... More
Hodge ideals and spectrum of isolated hypersurface singularitiesApr 04 2019We introduce Hodge ideal spectrum for isolated hypersurface singularities to see the difference between the Hodge ideals and the microlocal $V$-filtration modulo the Jacobian ideal. We compare the Hodge ideal spectrum with the Steenbrink spectrum that ... More
Asymmetric-valued Spectrum Auction and Competition in Wireless Broadband ServicesJul 30 2013Jan 25 2014We study bidding and pricing competition between two spiteful mobile network operators (MNOs) with considering their existing spectrum holdings. Given asymmetric-valued spectrum blocks are auctioned off to them via a first-price sealed-bid auction, we ... More
Nature of Orbital and Spin Rashba Coupling in the Surface Bands of SrTiO3 and KTaO3Apr 28 2014Tight-binding models for the recently observed surface electronic bands of SrTiO3 and KTaO3 are analyzed with a view to bringing out the relevance of momentum-space chiral angular momentum structures of both orbital and spin origins. Depending on the ... More
Addendum to the paper "Hypersurfaces with Isometric Reeb Flow in Complex hyperbolic Two-Plane Grassmannians"Oct 22 2014We classify all of real hypersurfaces $M$ with Reeb invariant shape operator in complex hyperbolic two-plane Grassmannians $SU_{2,m}/S(U_2{\cdot}U_m)$, $m \geq 2$. Then it becomes a tube over a totally geodesic $SU_{2,m-1}/S(U_2{\cdot}U_{m-1})$ in $SU_{2,m}/S(U_2{\cdot}U_m)$ ... More
Catalyst design using actively learned machine with non-ab initio input features towards CO2 reduction reactionsSep 14 2017In conventional chemisorption model, the d-band center theory (augmented sometimes with the upper edge of d-band for imporved accuarcy) plays a central role in predicting adsorption energies and catalytic activity as a function of d-band center of the ... More
Fragility, Stokes-Einstein violation, and correlated local excitations in a coarse-grained model of an ionic liquidFeb 03 2010Dynamics of a coarse-grained model for the room-temperature ionic liquid, 1-ethyl-3-methylimidazolium hexafluorophosphate, couched in the united-atom site representation are studied via molecular dynamics simulations. The dynamically heterogeneous behavior ... More
Can Deep Neural Networks Match the Related Objects?: A Survey on ImageNet-trained Classification ModelsSep 12 2017Deep neural networks (DNNs) have shown the state-of-the-art level of performances in wide range of complicated tasks. In recent years, the studies have been actively conducted to analyze the black box characteristics of DNNs and to grasp the learning ... More
Equivariant hyperbolization of $3$-manifolds via homology cobordismsApr 11 2018The main result of this paper is that any $3$-dimensional manifold with a finite group action is equivariantly, invertibly homology cobordant to a hyperbolic manifold; this result holds with suitable twisted coefficients as well. The following two consequences ... More
In-medium modified energy-momentum tensor form factors of the nucleon within the framework of a $π$-$ρ$-$ω$ soliton modelFeb 02 2014May 29 2014We investigate the energy-momentum tensor form factors of the nucleon in nuclear medium, based on an in-medium modified $\pi$-$\rho$-$\omega$ soliton model, with medium modifications of the mesons considered. The results allow us to establish general ... More
Highest weight modules over quantum queer Lie superalgebra U_q(q(n))Jun 01 2009Jan 09 2011In this paper, we investigate the structure of highest weight modules over the quantum queer superalgebra $U_q(q(n))$. The key ingredients are the triangular decomposition of $U_q(q(n))$ and the classification of finite dimensional irreducible modules ... More
In-medium modified $π$-$ρ$-$ω$ mesonic Lagrangian and properties of nuclear matterDec 19 2012We investigate the bulk properties of symmetric nuclear matter within the framework of an in-medium modified chiral solitonic model with $\pi$, $\rho$ and $\omega$ mesons. We consider the modification of meson degrees of freedom in nuclear matter, based ... More
Polaron Absorption in a Perovskite Manganite La0.7Ca0.3MnO3Apr 16 1998Temperature dependent optical conductivity spectra of a La0.7Ca0.3MnO3 (LCMO) sample were measured. In the metallic regime at very low temperatures, they clearly showed two types of absorption features, i.e., a sharp Drude peak and a broad mid-infrared ... More
Hyperspectral optical diffraction tomographyNov 05 2015Here, we present a novel microscopic technique for measuring wavelength-dependent three-dimensional (3-D) distributions of the refractive indices (RIs) of microscopic samples in the visible wavelengths. Employing 3-D quantitative phase microscopy techniques ... More
Current-Induced Resonant Motion of a Magnetic Vortex Core: Effect of Nonadiabatic Spin TorqueSep 05 2008The current-induced resonant excitation of a magnetic vortex core is investigated by means of analytical and micromagnetic calculations. We find that the radius and the phase shift of the resonant motion are not correctly described by the analytical equations ... More
X-ray Photoemission Study of the Infinite-Layer Cuprate Superconductor Sr0.9La0.1CuO2Apr 19 2001Jul 10 2001The electron-doped infinite-layer superconductor Sr0.9La0.1CuO2 is studied with x-ray photoemission spectroscopy (XPS). A nonaqueous chemical etchant is shown to effectively remove contaminants and to yield surfaces from which signals intrinsic to the ... More
Pressure dependent thermoelectric power of MgB$_2$ superconductorApr 24 2001We have measured temperature dependence of thermoelectric power (TEP) on MgB$_2$ superconductor under hydrostatic pressure. The sign and temperature dependence of TEP shows metallic hole carriers are dominant with activation type contribution at higher ... More
Microscopic mechanism of tunable band gap in potassium doped few-layer black phosphorusAug 02 2017Aug 04 2017Tuning band gaps in two-dimensional (2D) materials is of great interest in the fundamental and practical aspects of contemporary material sciences. Recently, black phosphorus (BP) consisting of stacked layers of phosphorene was experimentally observed ... More
Quantum Localization in Open Chaotic SystemsFeb 10 2008We study a quasi-Floquet state of a $\delta$-kicked rotor with absorbing boundaries focusing on the nature of the dynamical localization in open quantum systems. The localization lengths $\xi$ of lossy quasi-Floquet states located near the absorbing boundaries ... More
Comparing Sample-wise Learnability Across Deep Neural Network ModelsJan 08 2019Estimating the relative importance of each sample in a training set has important practical and theoretical value, such as in importance sampling or curriculum learning. This kind of focus on individual samples invokes the concept of sample-wise learnability: ... More
Neural Sign Language Translation based on Human Keypoint EstimationNov 28 2018Jun 21 2019We propose a sign language translation system based on human keypoint estimation. It is well-known that many problems in the field of computer vision require a massive amount of dataset to train deep neural network models. The situation is even worse ... More
Distinctive-attribute Extraction for Image CaptioningJul 25 2018Image captioning, an open research issue, has been evolved with the progress of deep neural networks. Convolutional neural networks (CNNs) and recurrent neural networks (RNNs) are employed to compute image features and generate natural language descriptions ... More