Results for "Ehsan Hajiramezanali"

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Non-Linear Non-Stationary Heteroscedasticity Volatility for Tracking of Jump ProcessesFeb 12 2019In this paper, we introduce a new jump process modeling which involves a particular kind of non-Gaussian stochastic processes with random jumps at random time points. The main goal of this study is to provide an accurate tracking technique based on non-linear ... More
A Novel Maneuvering Target Tracking Approach by Stochastic Volatility GARCH ModelFeb 12 2019In this paper, we introduce a new single model maneuvering target tracking approach using stochastic differential equation (SDE) based on GARCH volatility. The traditional input estimation (IE) techniques assume constant acceleration level which do not ... More
Scalable optimal Bayesian classification of single-cell trajectories under regulatory model uncertaintyFeb 08 2019Single-cell gene expression measurements offer opportunities in deriving mechanistic understanding of complex diseases, including cancer. However, due to the complex regulatory machinery of the cell, gene regulatory network (GRN) model inference based ... More
Differential Expression Analysis of Dynamical Sequencing Count Data with a Gamma Markov ChainMar 07 2018Next-generation sequencing (NGS) to profile temporal changes in living systems is gaining more attention for deriving better insights into the underlying biological mechanisms compared to traditional static sequencing experiments. Nonetheless, the majority ... More
Bayesian multi-domain learning for cancer subtype discovery from next-generation sequencing count dataOct 22 2018Precision medicine aims for personalized prognosis and therapeutics by utilizing recent genome-scale high-throughput profiling techniques, including next-generation sequencing (NGS). However, translating NGS data faces several challenges. First, NGS count ... More
On SYM theory and all order Bulk Singularity Structures of BPS Strings in type II theoryMar 16 2016The complete form of the S-matrix elements of three supersymmetric Yang-Mills (SYM), namely a transverse scalar field, two world volume gauge fields and a Potential $C_{n-1}$ Ramond-Ramond (RR) form field has been investigated. Basically, in order to ... More
The Impact of Enhanced Iron Opacity on Massive Star Pulsations: Updated Instability StripsSep 29 2015Recently, Bailey et al. (2015) made a direct measurement of the Iron opacity at the physical conditions of the solar tachocline. They found that the wavelength-integrated Iron opacity is roughly 75% higher that what the OP and OPAL models predict. Here, ... More
On Singularity Structure, New RR-String Couplings in Asymmetric Picture and Their All Order $α'$ CorrectionsJul 09 2015Jan 04 2016We have analyzed in detail the four and five point functions of the string theory amplitudes including a closed string Ramond-Ramond (RR) in an asymmetric picture and either two or three transverse scalar fields in both IIA and IIB. The complete forms ... More
Remarks on the mixed Ramond -Ramond, open string scattering amplitudes of BPS, non-BPS and brane-anti braneFeb 23 2015Oct 16 2015From the world-sheet point of view we compute three, four and five point BPS and non-BPS scattering amplitudes of type IIA and IIB superstring theory. All these the mixed S-matrix elements including a closed string Ramond-Ramond (RR) in the bulk and a ... More
Modeling and Nonlinear Control of Gantry Crane Using Feedback Linearization MethodMay 22 2014Due to the requirements of high positioning accuracy, small swing angle, short transportation time, and high safety, both motion and stabilization control for an gantry crane system becomes an interesting issue in the field of control technology development. ... More
Asteroseismic Diagnostics for Semi-Convection in B Stars in the Era of K2Jul 24 2014Semi-convection is a slow mixing process in chemically-inhomogeneous radiative interiors of stars. In massive OB stars, it is important during the main sequence. However, the efficiency of this mixing mechanism is not properly gauged yet. Here, we argue ... More
On effective actions of BPS branes and their higher derivative correctionsMar 01 2010May 26 2010We calculate in detail the disk level S-matrix element of one Ramond-Ramond field and three gauge field vertex operators in the world volume of BPS branes, to find four gauge field couplings to all orders of $\alpha'$ up to on-shell ambiguity. Then using ... More
Three-dimensional Hubbard model in the thermodynamic limitMar 08 2016Sep 11 2016We employ the numerical linked-cluster expansion to study finite-temperature properties of the uniform cubic lattice Hubbard model in the thermodynamic limit for a wide range of interaction strengths and densities. We carry out the expansion to the 9th ... More
On WZ and RR Couplings of BPS Branes and their all order $α'$ Corrections in IIB, IIANov 02 2016We compute all three and four point couplings of BPS $D_{p}$-branes for all different nonzero $p$-values on the entire world volume and transverse directions. We start finding out all four point function supersymmetric Wess-Zumino (WZ) actions of one ... More
Design of an Alarm System for Isfahan Ozone Level based on Artificial Intelligence Predictor ModelsNov 08 2015The ozone level prediction is an important task of air quality agencies of modern cities. In this paper, we design an ozone level alarm system (OLP) for Isfahan city and test it through the real word data from 1-1-2000 to 7-6-2011. We propose a computer ... More
Discrete Symmetry Transformation of Baryon- and Lepton-Nonconserving ProcessesApr 13 2016Aug 25 2016We consider discrete transformations (C, P, T and CP) of baryon- and lepton-nonconserving processes. It has long been thought that choosing any of the allowed values ($\pm1$ and $\pm i$) as discrete transformation arbitrary phases, do not have any effect ... More
Selection Rules and RR Couplings on Non-BPS BranesJul 12 2013Nov 10 2013We compute three and four point functions of the non-BPS scattering amplitudes, including a closed string Ramond-Ramond, gauge/scalar and tachyon in type IIA (IIB) superstring theories. We then discover a unique expansion for tachyon amplitudes in both ... More
Shedding light on new Wess-Zumino couplings with their corrections to all orders in alpha-primeNov 11 2012Mar 14 2013Motivated by arXiv:1203.5553, we continue to match super string amplitudes with their own effective field theory. We carry out within full details the computations of the complete form of the amplitude of one closed string Ramond-Ramond field and three ... More
Learning Markov Network Structure using Brownian Distance CovarianceJun 27 2012In this paper, we present a simple non-parametric method for learning the structure of undirected graphs from data that drawn from an underlying unknown distribution. We propose to use Brownian distance covariance to estimate the conditional independences ... More
On the shape of core overshooting in stellar model computations, and asteroseismic testsAug 04 2015Aug 10 2015Slowly pulsating B stars (SPB) and $\gamma$ Dor stars pulsate in high-order gravity (g-) modes. The frequencies of g-modes are sensitive to the detailed structure and evolution history of stars having convective cores. Receding convective cores in OB-type ... More
SuperYang-Mills, Chern-Simons couplings and their all order $α'$ corrections in IIB superstring theoryOct 30 2013Jul 24 2014We explore the closed form of the correlation function of four spin operators (including one closed string Ramond-Ramond (RR) and two open string fermions) and one current in ten dimensions, to be able to find the complete and the closed form of the amplitude ... More
Closed string Ramond-Ramond proposed higher derivative interactions on fermionic amplitudes in IIBFeb 20 2013Jan 03 2014The complete form of the amplitude of one closed string Ramond-Ramond (RR), two fermionic strings and one scalar field in IIB superstring theory has been computed in detail. Deriving $<V_{C}V_{\bar\psi}V_{\psi} V_{\phi}>$ by using suitable gauge fixing, ... More
On D-brane anti D-brane effective actions and their corrections to all orders in alpha-primeNov 23 2012Aug 10 2013Based on a four point function, the S-matrix elements at disk level of the scattering amplitude of one closed string Ramond-Ramond field ($C$), two tachyons and one scalar field, we find out new couplings in brane anti brane effective actions for $p=n,p+2=n$ ... More
Remarks On $\aleph_0$-InjectivityOct 11 2009In this article we continue to study $\aleph_0$-injectivity.
Power spectrum analysis of limb and disk spicule using Hinode Ca H line broadband filterMar 26 2014We present observations of a solar quiet region obtained using Hinode Solar Optical telescope (SOT) in Ca II H line with broadband filter taken on November 2006. We study offlimb and on disk spicules to find a counterpart of limb spicule on the disk. ... More
SYM, Chern-Simons, Wess-Zumino Couplings and their higher derivative corrections in IIA Superstring theoryMar 05 2014Oct 30 2014We find the entire form of the amplitude of two fermion strings (with different chirality), a massless scalar field and one closed string Ramond-Ramond (RR) in IIA superstring theory which is different from its IIB one. We make use of a very particular ... More
Well-posedness of Wasserstein Gradient Flow Solutions of Higher Order Evolution EquationsDec 19 2011Jan 17 2012A relaxed notion of displacement convexity is defined and used to establish short time existence and uniqueness of Wasserstein gradient flows for higher order energy functionals. As an application, local and global well-posedness of different higher order ... More
On the Graded Annihilators of Right Modules Over The Frobenius Skew Polynomial RingSep 22 2011Oct 19 2012Let R be a commutative Noetherian ring of prime characteristic and M be an x-divisible right R[x,f]-module that is Noetherian as R-module. We give an affirmative answer to the question of Sharp and Yoshino in the case where R is semi-local and prove that ... More
On RR Couplings, Singularity Structures and all order $α'$ contact interactions to BPS String AmplitudesJun 29 2015Dec 10 2015We evaluate five point world-sheet string theory amplitudes of one transverse scalar field, two world volume gauge fields ( and two transverse scalars, a gauge field) in the presence of a closed string Ramond-Ramond vertex operator in its symmetric picture. ... More
On higher derivative corrections to Wess-Zumino and Tachyonic actions in type II super string theoryMar 06 2012Apr 17 2013We evaluate in detail the string scattering amplitude to compute different interactions of two massless scalars, one tachyon and one closed string Ramond-Ramond field in type II super string theory. In particular we find two scalar field and two tachyon ... More
Three Point Tree Level Amplitude in Superstring TheoryFeb 24 2011In order to check the definite amplitude and the exact zero result of the amplitude of three massless points $(CAA)$ in both string theory and field theory side for $p=n$ case and to find all gauge field couplings to R-R closed string, we investigate ... More
Remarks on Non-BPS String Amplitudes and their all Order $α'$ Contact InteractionsSep 06 2016We explore the entire form of S-Matrix elements of an antisymmetric potential $C_{n-1}$ Ramond-Ramond (RR) form field, a tachyon and two transverse scalar fields on both world volume and transverse directions of type IIB (IIA) superstring theory. Apart ... More
On Bulk Singularity Structures and all order $α'$ Contact Terms of BPS String AmplitudesApr 12 2016Aug 23 2016The entire form of the amplitude of three SYM ( involving two transverse scalar fields, a gauge field) and a potential $C_{n-1}$ Ramond-Ramond (RR) form field is found out. We first derive $<V_{C^{-2}} V_{A^{0}} V_{\phi ^{0}} V_{\phi ^{0}}>$ and then ... More
On D-brane-Anti D-brane Effective actions and their all order Bulk Singularity StructuresJan 25 2016Mar 24 2016All four point functions of brane anti brane system including their correct all order $\alpha'$ corrections have been addressed. All five point functions of one closed string Ramond-Ramond (RR), two real tachyons and either one gauge field or the scalar ... More
On RR Couplings and Bulk Singularity Structures of Non-BPS BranesNov 16 2015Jul 14 2016We compute the five point world sheet scattering amplitude of a symmetric closed string Ramond-Ramond , a transverse scalar field, a world volume gauge field and a real tachyon in both world volume and transverse directions of brane in type IIA and IIB ... More
More on Ramond-Ramond, SYM, WZ couplings and their corrections in IIAMar 27 2014Oct 30 2014We obtain the closed form of the correlation function of one current and four spin operators (with different chiralities ) in type IIA superstring theory. The complete form of the S-matrix of one gauge , two fermions (with different chiralities) and one ... More
All order $α'$ higher derivative corrections to non-BPS branes of type IIB Super string theoryApr 12 2013Jul 02 2013By dealing with the evaluation of string theory correlators of $<V_C V_T V_{\bar\Psi} V_\Psi>$, the complete and closed form of the amplitude of two fermion fields, one tachyon and one closed string Ramond-Ramond field in type IIB superstring theory is ... More
A Jacobian Separable 2-D Finite-Element Method for Electromagnetic Waveguide ProblemsMar 11 2016We propose an efficient finite-element analysis of the vector wave equation in a class of relatively general curved polygons. The proposed method is suitable for an accurate and efficient calculation of the propagation constants of waveguides filled with ... More
On the fractional Black-Scholes market with transaction costsMay 03 2010We consider fractional Black-Scholes market with proportional transaction costs. When transaction costs are present, one trades periodically i.e. we have the discrete trading with equidistance $n^{-1}$ between trading times. We derive a non trivial hedging ... More
Reduction of some homological conjectures to excellent unique factorization domainsJun 30 2016Jul 28 2016In this article, applying the quasi-Gorenstein analogous of the Ulrich's deformation of certain Gorenstein rings we show that some homological conjectures, including the Monomial Conjecture, Big Cohen-Macaulay Algebra Conjecture as well as the Small Cohen-Macaulay ... More
Radial Symmetry of Large Solutions of Semilinear Elliptic Equations with ConvectionJul 13 2012Jul 18 2012We study radial symmetry of large solutions of the semi-linear elliptic problem \Delta u + \nabla h.\nabla u = f(|x|,u), and we provide sharp conditions under which the problem has a radial solution. The result is independent of the rate of growth of ... More
Thermodynamics of strongly interacting fermions in two-dimensional optical latticesApr 28 2011Nov 14 2011We study finite-temperature properties of strongly correlated fermions in two-dimensional optical lattices by means of numerical linked cluster expansions, a computational technique that allows one to obtain exact results in the thermodynamic limit. We ... More
Inducing Semantic Representation from Text by Jointly Predicting and Factorizing RelationsDec 19 2014Apr 16 2015In this work, we propose a new method to integrate two recent lines of work: unsupervised induction of shallow semantics (e.g., semantic roles) and factorization of relations in text and knowledge bases. Our model consists of two components: (1) an encoding ... More
A Study of Quasi-Gorenstein RingsAug 19 2015Sep 04 2016In this paper several quasi-Gorenstein counterparts to some known properties of Gorenstein rings are given. We, furthermore, give an explicit description of the attach prime ideals of certain local cohomology modules.
Numerical study of flow patterns and heat transfer in mini twisted oval tubesNov 06 2018Flow patterns and heat transfer inside mini twisted oval tubes (TOTs) heated by constant-temperature walls are numerically investigated. Different configurations of tubes are simulated using water as the working fluid with temperature-dependent thermo-physical ... More
On a new Sheffer class of polynomials related to normal product distributionFeb 19 2018Consider a generic random element $F_\infty= \sum_{\text{finite}} \lambda_k (N^2_k -1)$ in the second Wiener chaos with a finite number of non-zero coefficients in the spectral representation where $(N_k)_{k \ge 1}$ is a sequence of i.i.d $\mathscr{N}(0,1)$. ... More
Oscillations in solar Jets Observed with the SOT of Hinode: Viscous Effects during ReconnectionMar 04 2014Transverse oscillatory motions and recurrence behavior in the chromospheric jets observed by Hinode/SOT are studied. A comparison is considered with the behavior that was noticed in coronal X-ray jets observed by Hinode/XRT. A jet like bundle observed ... More
A de Bruijn - Erdős theorem and metric spacesMay 31 2009De Bruijn and Erd\H{o}s proved that every noncollinear set of n points in the plane determines at least n distinct lines. Chen and Chv\'atal suggested a possible generalization of this theorem in the framework of metric spaces. We provide partial results ... More
On the Structure and Efficient Computation of IsoRank Node SimilaritiesFeb 01 2016Feb 24 2016The alignment of protein-protein interaction (PPI) networks has many applications, such as the detection of conserved biological network motifs, the prediction of protein interactions, and the reconstruction of phylogenetic trees [1, 2, 3]. IsoRank is ... More
Goodness-of-fit testing for the Cauchy distribution with application to financial modelingJun 24 2016This article deals with goodness-of-fit test for the Cauchy distribution. Some tests based on Kullback-Leibler information are proposed, and shown to be consistent. Monte Carlo evidence indicates that the tests have satisfactory performances against symmetric ... More
Each normalized state is a member of an orthonormal basis: A simple proofMay 22 2015In a finite dimensional Hilbert space, each normalized vector (state) can be chosen as a member of an orthonormal basis of the space. We give a proof of this statement in a manner that seems to be more comprehensible for physics students than the formal ... More
Relativistic and non-relativistic quantum Brownian motion in an anisotropic dissipative mediumAug 24 2013Jan 30 2014Using a minimal-coupling-scheme we investigate the quantum Brownian motion of a particle in an anisotropic-dissipative-medium under the influence of an arbitrary potential in both relativistic and non-relativistic regimes. A general quantum Langevin equation ... More
Anonymous Communication in Peer-to-Peer Networks for providing more Privacy and SecurityAug 15 2012One of the most important issues in peer-to-peer networks is anonymity. The major anonymity for peer-to-peer users concerned with the users' identities and actions which can be revealed by any other members. There are many approaches proposed to provide ... More
Sparse Subspace Clustering: Algorithm, Theory, and ApplicationsMar 05 2012Feb 05 2013In many real-world problems, we are dealing with collections of high-dimensional data, such as images, videos, text and web documents, DNA microarray data, and more. Often, high-dimensional data lie close to low-dimensional structures corresponding to ... More
Thermodynamics of the Antiferromagnetic Heisenberg Model on the Checkerboard LatticeSep 23 2010Apr 21 2011Employing numerical linked-cluster expansions (NLCEs) along with exact diagonalizations of finite clusters with periodic boundary condition, we study the energy, specific heat, entropy, and various susceptibilities of the antiferromagnetic Heisenberg ... More
Extremal rotating solutions in Horava GravityJun 08 2009Feb 11 2010Recently a new four-dimensional non relativistic renormalizable theory of gravity was proposed by Horava. In this paper we have found different near horizon geometries in Horava gravity. We find the rotating solutions in a special range of parameters ... More
Incidence-based Estimates of Healthy Life Expectancy for the United Kingdom: Coherence between Transition Probabilities and Aggregate Life TablesApr 10 2006Apr 11 2006Will the United Kingdom's ageing population be fit and independent, or suffer from greater chronic ill health? Healthy life expectancy is commonly used to assess this: it is an estimate of how many years are lived in good health over the lifespan. This ... More
Stabilizing synchrony by inhomogeneityMar 20 2015We show that for two identical neuronal oscillators with strictly positive phase resetting curve, isochronous synchrony is an unstable attractor and arbitrarily weak noise can destroy entrainment and generate intermittent phase slips. Small inhomogeneity ... More
Quantum dissipative Higgs modelJan 14 2015By using a continuum of oscillators as a reservoir, we present a classical and a quantum-mechanical treatment for the Higgs model in the presence of dissipation. In this base, a fully canonical approach is used to quantize the damped particle on a spherical ... More
Lattice modes in a dusty plasma crystalOct 06 2013A model is presented to explain the normal mode features of dust particles in a planar zigzag crystal chain for the first and second neighbors. The degrees of freedom of particles are the longitudinal and transverse displacements in plane coupled by the ... More
Block-Sparse Recovery via Convex OptimizationApr 04 2011Apr 13 2012Given a dictionary that consists of multiple blocks and a signal that lives in the range space of only a few blocks, we study the problem of finding a block-sparse representation of the signal, i.e., a representation that uses the minimum number of blocks. ... More
Code Failure Prediction and Pattern Extraction using LSTM NetworksDec 13 2018In this paper, we use a well-known Deep Learning technique called Long Short Term Memory (LSTM) recurrent neural networks to find sessions that are prone to code failure in applications that rely on telemetry data for system health monitoring. We also ... More
Inference on a Distribution Function from Ranked Set SamplesApr 25 2013Jul 02 2018Consider independent observations $(X_1,R_1)$, $(X_2,R_2)$, \ldots, $(X_n,R_n)$ with random or fixed ranks $R_i \in \{1,2,\ldots,k\}$, while conditional on $R_i = r$, the random variable $X_i$ has the same distribution as the $r$-th order statistic within ... More
Optimal Berry-Esseen bounds on the Poisson spaceMay 11 2015May 12 2015We establish new lower bounds for the normal approximation in the Wasserstein distance of random variables that are functionals of a Poisson measure. Our results generalize previous findings by Nourdin and Peccati (2012, 2015) and Bierm\'e, Bonami, Nourdin ... More
Spectral characterization of the quadratic variation of mixed Brownian fractional Brownian motionMay 24 2010Mar 06 2012Dzhaparidze and Spreij [5] showed that the quadratic variation of a semimartingale can be approximated using a randomized periodogram. We show that the same approximation is valid for a special class of continuous stochastic processes. This class contains ... More
Anisotropies in thermal Casimir interactions: ellipsoidal colloids trapped at a fluid interfaceFeb 23 2009Apr 21 2009We study the effective interaction between two ellipsoidal particles at the interface of two fluid phases which are mediated by thermal fluctuations of the interface. In this system the restriction of the long--ranged interface fluctuations by particles ... More
Control-theoretic Approach to Communication with Feedback: Fundamental Limits and Code DesignJun 28 2010Feedback communication is studied from a control-theoretic perspective, mapping the communication problem to a control problem in which the control signal is received through the same noisy channel as in the communication problem, and the (nonlinear and ... More
Quantum optical effective-medium theory for layered metamaterialsJun 25 2016The quantum optics of metamaterials starts with the question whether the same effective-medium theories apply as in classical optics. In general the answer is negative. For active plasmonics but also for some passive metamaterials, we show that an additional ... More
A New Performance Guarantee for Orthogonal Matching Pursuit Using Mutual CoherenceAug 01 2016Oct 22 2016In this paper we present a new coherence-based performance guarantee for the Orthogonal Matching Pursuit (OMP) algorithm. An upper bound for the probability of correctly identifying the support of a sparse signal with additive white Gaussian noise is ... More
Vesicle adhesion reveals novel universal relationships for biophysical characterizationApr 10 2016Apr 29 2016Adhesion plays an integral role in diverse biological functions ranging from cellular transport to tissue development. Estimation of adhesion strength, therefore, becomes important to gain biophysical insight into these phenomena. In this Letter, we use ... More
Variance Estimation in Ranked Set Sampling Using a Concomitant VariableJun 22 2015We propose a nonparametric variance estimator when ranked set sampling (RSS) and judgment post stratification (JPS) are applied by measuring a concomitant variable. Our proposed estimator is obtained by conditioning on observed concomitant values and ... More
Parameter estimation based on discrete observations of fractional Ornstein-Uhlenbeck process of the second kindApr 09 2013Sep 11 2014Fractional Ornstein-Uhlenbeck process of the second kind $(\text{fOU}_{2})$ is solution of the Langevin equation $\mathrm{d}X_t = -\theta X_t\,\mathrm{d}t+\mathrm{d}Y_t^{(1)}, \ \theta >0$ with Gaussian driving noise $ Y_t^{(1)} := \int^t_0 e^{-s} \,\mathrm{d}B_{a_s}$, ... More
An Efficient Method Based on Genetic Algorithms to Solve Sensor Network Optimization ProblemApr 03 2011Minimization of the number of cluster heads in a wireless sensor network is a very important problem to reduce channel contention and to improve the efficiency of the algorithm when executed at the level of cluster-heads. In this paper, we propose an ... More
Finite temperature Cherenkov radiation in the presence of a magnetodielectric mediumSep 15 2010A canonical approach to Cherenkov radiation in the presence of a magnetodielectric medium is presented in classical, nonrelativistic and relativistic quantum regimes. The equations of motion for the canonical variables are solved explicitly for both positive ... More
Effect of particle statistics in strongly correlated two-dimensional Hubbard modelsApr 06 2012Aug 30 2012We study the onset of particle statistics effects as the temperature is lowered in strongly correlated two-dimensional Hubbard models. We utilize numerical linked-cluster expansions and focus on the properties of interacting lattice fermions and two-component ... More
Timing, Carrier, and Frame Synchronization of Burst-Mode CPMOct 02 2013Jan 23 2014In this paper, we propose a complete synchronization algorithm for continuous phase modulation (CPM) signals in burst-mode transmission over additive white Gaussian noise (AWGN) channels. The timing and carrier recovery are performed through a data-aided ... More
Unsupervised Induction of Semantic Roles within a Reconstruction-Error Minimization FrameworkDec 08 2014We introduce a new approach to unsupervised estimation of feature-rich semantic role labeling models. Our model consists of two components: (1) an encoding component: a semantic role labeling model which predicts roles given a rich set of syntactic and ... More
Inference on a Distribution Function from Ranked Set SamplesApr 25 2013Oct 14 2013Consider independent observations (X_1,R_1), (X_2,R_2), ..., (X_n,R_n) with random or fixed ranks R_i in {1,2,...,k}, while conditional on R_i = r, the random variable X_i has the same distribution as the r-th order statistic within a random sample of ... More
Rate of convergence for discretization of integrals with respect to Fractional Brownian motionMay 21 2012In this article, an uniform discretization of stochastic integrals $\int_{0}^{1} f'_-(B_t)\ud B_t$, with respect to fractional Brownian motion with Hurst parameter $H \in (1/2,1)$, for a large class of convex functions $f$ is considered. In Statistics ... More
New moments criteria for convergence towards normal product/tetilla lawsAug 25 2017Jan 17 2019In the framework of classical probability, we consider the normal product distribution $F_\infty \sim N_1 \times N_2$ where $N_1, N_2$ are two independent standard normal random variable, and in the setting of free probability, $F_\infty \sim \left( S_1 ... More
A general approach to small deviation via concentration of measuresJul 14 2014Feb 17 2015We provide a general approach to obtain upper bounds for small deviations $ \mathbb{P}(\Vert y \Vert \le \epsilon)$ in different norms, namely the supremum and $\beta$- H\"older norms. The large class of processes $y$ under consideration takes the form ... More
More On Critical Collapse of Axion-Dilaton System in Dimension FourJul 04 2013Oct 02 2013We complete our previous study of critical gravitational collapse in the axion-dilaton system by analysing the hyperbolic and parabolic ans\"atze. As could be expected, the corresponding Choptuik exponents in four-dimensions differ from the elliptic case. ... More
A New Performance Guarantee for Orthogonal Matching Pursuit Using Mutual CoherenceAug 01 2016Aug 17 2016In this paper we present a new coherence-based performance guarantee for the Orthogonal Matching Pursuit (OMP) algorithm. An upper bound for the probability of correctly identifying the support of a sparse signal with additive white Gaussian noise is ... More
Drift parameter estimation for fractional Ornstein-Uhlenbeck process of the Second KindFeb 25 2013Fractional Ornstein-Uhlenbeck process of the second kind $(\text{fOU}_{2})$ is solution of the Langevin equation $\mathrm{d}X_t = -\theta X_t\,\mathrm{d}t+\mathrm{d}Y_t^{(1)}, \ \theta >0$ with driving noise $ Y_t^{(1)} := \int^t_0 e^{-s} \,\mathrm{d}B_{a_s}; ... More
Critical Collapse in the Axion-Dilaton System in Diverse DimensionsJul 30 2011We study the gravitational collapse of the axion-dilaton system suggested by type IIB string theory in dimensions ranging from four to ten. We extend previous analysis concerning the role played by the global SL(2,R) symmetry and we evaluate the Choptuik ... More
Similarity-based Text Recognition by Deeply Supervised Siamese NetworkNov 13 2015Jul 05 2016In this paper, we propose a new text recognition model based on measuring the visual similarity of text and predicting the content of unlabeled texts. First a Siamese convolutional network is trained with deep supervision on a labeled training dataset. ... More
High-energy neutrino emission in gravitational collapsesOct 02 2012In this article, we present a study of high-energy neutrino emission in gravitational collapse. A compact star is treated as a complete degenerate Fermi gas of neutrons, protons and electrons. In gravitational collapse, its density reaches the thresholds ... More
Divergence-Based Motivation for Online EM and Combining Hidden Variable ModelsFeb 11 2019Expectation-Maximization (EM) is the fallback method for parameter estimation of hidden (aka latent) variable models. Given the full batch of data, EM forms an upper-bound of the negative log-likelihood of the model at each iteration and then updates ... More
More on WZ action of non-BPS branesDec 22 2008Jan 03 2009We calculate the disk level S-matrix element of one Ramond-Ramond, two gauge fields and one tachyon vertex operators in the world volume of non-BPS branes. We then find the momentum expansion of this amplitude and show that the infinite tachyon/massless ... More
Universality in all-order $α'$ corrections to BPS/non-BPS brane world volume theoriesMay 23 2012Jul 11 2012Knowledge of all-$\alpha'$ higher derivative corrections to leading order BPS and non-BPS brane actions would serve in future endeavor of determining the complete form of the non-abelian BPS and tachyonic effective actions. In this paper, we note that ... More
A New Approach to Cold Start in Peer to Peer File Sharing NetworksDec 05 2009Solving free riding and selecting a reliable service provider in P2P networks has been separately investigated in last few years. Using trust has shown to be one of the best ways of solving these problems. But using this approach to simultaneously deal ... More
Self-Stabilization Through the Lens of Game TheoryJan 15 2019In 1974 E.W. Dijkstra introduced the seminal concept of self-stabilization that turned out to be one of the main approaches to fault-tolerant computing. We show here how his three solutions can be formalized and reasoned about using the concepts of game ... More
A more globally accurate dimensionality reduction method using tripletsMar 01 2018We first show that the commonly used dimensionality reduction (DR) methods such as t-SNE and LargeVis poorly capture the global structure of the data in the low dimensional embedding. We show this via a number of tests for the DR methods that can be easily ... More
Two-temperature logistic regression based on the Tsallis divergenceMay 19 2017We develop a variant of multiclass logistic regression that achieves three properties: i) We minimize a non-convex surrogate loss which makes the method robust to outliers, ii) our method allows transitioning between non-convex and convex losses by the ... More
Chatter Avoidance in Delayed Feedback Attitude Control with MRP Shadow Set SwitchingSep 29 2015The chattering response at the MRP shadow set switching point for the controlled attitude dynamics of a rigid tumbling spacecraft using delayed state feedback control with MRPs is investigated, where the time delay is assumed to be in the measurement ... More
More on closed string induced higher derivative interactions on D-branesMar 25 2012Jun 05 2012In our continued efforts of matching full string computations with the corresponding effective field theory computations, we evaluate string theory correlators in closed forms. In particular, we consider a correlator between three SYM vertex operators ... More
On Wess-Zumino terms of Brane-Antibrane systemsOct 31 2007We calculate the disk level S-matrix element of one closed string RR field, two open string tachyons and one gauge field in type II superstring theory. An expansion for the S-matrix element has been found that its four leading order terms are reproduced ... More
Improving the K-means algorithm using improved downhill simplex searchSep 05 2012The k-means algorithm is one of the well-known and most popular clustering algorithms. K-means seeks an optimal partition of the data by minimizing the sum of squared error with an iterative optimization procedure, which belongs to the category of hill ... More
A Fundamental Limit on Propagation Loss of Waveguides with Subwavelength Mode SizeNov 17 2014A fundamental trade-off relation between the cross sectional confinement and propagation length of an arbitrary mode of a general waveguide is presented. This limit is a generalization of the well-known diffraction limit for guided modes. The results ... More
Bidirectional LSTM-CRF for Clinical Concept ExtractionNov 25 2016Automated extraction of concepts from patient clinical records is an essential facilitator of clinical research. For this reason, the 2010 i2b2/VA Natural Language Processing Challenges for Clinical Records introduced a concept extraction task aimed at ... More