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Results for "Farhad Khoeini"

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Thermal conductivity and thermal rectification of nanoporous graphene: A molecular dynamics simulationJun 11 2019Using non-equilibrium molecular dynamics (NEMD) simulation, we study thermal properties of the so-called nanoporous graphene (NPG) sheet which contains a series of nanoporous in an ordered way and was synthesized recently (Science 360 (2018), 199). The ... More
Optical Transitions and Localized Edge States in Skewed Phosphorene NanoribbonsFeb 06 2018Jun 29 2018Using the Tight Binding (TB) parameters extracted from Density Functional Theory (DFT) and Recursive Green's Function method, it is shown that skewed-zigzag black phosphorous (phosphorene) nanoribbons obtain large and tuneable bandgap in response to vertical ... More
Thermal transport in silicene nanotubes: Effects of length, grain boundary and strainJan 03 2019Thermal transport behavior in silicene nanotubes has become more important due to the application of these promising nanostructures in the engineering of next-generation nanoelectronic devices. We apply non-equilibrium molecular dynamics (NEMD) simulations ... More
Nonlinear Optical Susceptibilities and Linear Absorption in Phosphorene Nanoribbons: Ab initio studySep 06 2017Oct 16 2017Using Density Functional Theory (DFT) method we compute linear optical absorption spectra and nonlinear optical susceptibilities of hydrogen passivated armchair and zigzag Phosphorous Nanoribbons (aPNR and zPNR) as well as \alpha-phase phosphorous monolayer. ... More
Thermal transport across grain boundaries in polycrystalline silicene: a multiscale modelingJan 03 2019During the fabrication process of large scale silicene through common chemical vapor deposition (CVD) technique, polycrystalline films are quite likely to be produced, and the existence of Kapitza thermal resistance along grain boundaries could result ... More
Vesicle-like structure of lipid-based nanoparticles as drug delivery system revealed by molecular dynamics simulationsJan 03 2019Lipid-based drug delivery systems are considered as promising vehicles for hydrophobic drug compounds. Lipid distribution within the droplet can affect drug loading capacity in these carriers. It is extremely challenging to determine the nanostructure ... More
On some three color Ramsey numbers for paths, cycles, stripes and starsJul 21 2017For given graphs $G_{1}, G_{2}, ... , G_{k}, k \geq 2$, the multicolor Ramsey number $R(G_{1}, G_{2}, ... , G_{k})$ is the smallest integer $n$ such that if we arbitrarily color the edges of the complete graph of order $n$ with $k$ colors, then it always ... More
Fields Annihilation and Particles Creation in DBI inflationNov 19 2010Feb 08 2011We consider a model of DBI inflation where two stacks of mobile branes are moving ultra relativistically in a warped throat. The stack closer to the tip of the throat is annihilated with the background anti-branes while inflation proceeds by the second ... More
Non-Stochastic Hypothesis Testing with Application to Privacy Against Hypothesis-Testing AdversaryApr 16 2019In this paper, we consider privacy against hypothesis testing adversaries within a non-stochastic framework. We develop a theory of non-stochastic hypothesis testing by borrowing the notion of uncertain variables from non-stochastic information theory. ... More
Large scale-small scale duality and cosmological constantJun 29 1999We study a model of quantum cosmology originating from a classical model of gravitation where a self interacting scalar field is coupled to gravity with the metric undergoing a signature transition. We show that there are dual classical signature changing ... More
Carbon nanotube/metal corrosion issues for nanotube coatings and inclusions in a matrixNov 03 2018Corrosion is an inevitable phenomenon that is inherent in metals and even though there has been significant research on this subject, no ideal protection has been discovered to fully prevent corrosion. However, methods such as using protective coatings, ... More
Number of Wavevectors for Each Frequency in a Periodic StructureNov 05 2016Periodic structures have interesting acoustic and vibration properties making them suitable for a wide variety of applications. In a periodic structure, the number of frequencies for each wavevector depends on the degree of freedom of the unit cell. In ... More
On the largest reduced neighborhood clique cover number of a graphJun 08 2016Dec 11 2016Let $G$ be a graph and $t\ge 0$. A new graph parameter termed the largest reduced neighborhood clique cover number of $G$, denoted by ${\hat\beta}_t(G)$, is introduced. Specifically, ${\hat\beta}_t(G)$ is the largest, overall $t$-shallow minors $H$ of ... More
Clique Cover Width and Clique SumFeb 22 2015Feb 25 2015For a clique cover $C$ in the undirected graph $G$, the clique cover graph of $C$ is the graph obtained by contracting the vertices of each clique in $C$ into a single vertex. The clique cover width of G, denoted by $CCW(G)$, is the minimum value of the ... More
Noncommutative Simple Harmonic Oscillator in Quantum Gravitational WellMay 28 2016This work is mainly based on some theoretical surveys on two dimensional quantum gravitational well, considering harmonic oscillator potential causes an effective plank constant. We find that there is a similarity between two different cases, potential ... More
New representation results for planar graphsFeb 22 2015A universal representation theorem is derived that shows any graph is the intersection graph of one chordal graph, a number of co-bipartite graphs, and one unit interval graph. Central to the the result is the notion of the clique cover width which is ... More
Plane Symmetric, Cylindrically Symmetric and Spherically Symmetric Black Holes Solutions of Einstein Field EquationsOct 19 2014Dec 30 2014In this paper we present Plane symmetric, Cylindrically Symmetric and Spherically Symmetric Black hole or Vacuum solutions of Einstein Field Equations(EFEs). Some of these solutions are new which we have not seen in the literature. This calculation will ... More
On the largest reduced neighborhood clique cover number of a graphJun 08 2016Let $G$ be a graph and $t\ge 0$. A new graph parameter termed the largest reduced neighborhood clique cover number of $G$, denoted by ${\hat\beta}_t(G)$, is introduced. Roughly speaking ${\hat\beta}_t(G)$ is the largest, overall $t$-shallow minors $H$ ... More
Largest reduced neighborhood clique cover number revisitedMay 07 2017Let $G$ be a graph and $t\ge 0$. The largest reduced neighborhood clique cover number of $G$, denoted by ${\hat\beta}_t(G)$, is the largest, overall $t$-shallow minors $H$ of $G$, of the smallest number of cliques that can cover any closed neighborhood ... More
Size-Ramsey numbers of cycles versus a pathAug 23 2016The size-Ramsey number $\hat{R}(\mathcal{F},H)$ of a family of graphs $\mathcal{F}$ and a graph $H$ is the smallest integer $m$ such that there exists a graph $G$ on $m$ edges with the property that any colouring of the edges of $G$ with two colours, ... More
Cosmic Strings Collision in Cosmological BackgroundsApr 01 2010The collisions of cosmic strings loops and the dynamics of junctions formations in expanding backgrounds are studied. The key parameter controlling the dynamics of junctions formation, the cosmic strings zipping and unzipping is the relative size of the ... More
A simple upper bound for trace function of a hypergraph with applicationsFeb 22 2019Let ${H}=(V, {E})$ be a hypergraph on the vertex set $V$ and edge set ${E}\subseteq 2^V$. We show that number of distinct {\it traces} on any $k-$ subset of $V$, is most $k.{\hat \alpha}(H)$, where ${\hat \alpha}(H)$ is the {\it degeneracy} of $H$. The ... More
A simple upper bound for trace function of a hypergraph with applicationsFeb 22 2019Mar 06 2019Let ${H}=(V, {E})$ be a hypergraph on the vertex set $V$ and edge set ${E}\subseteq 2^V$. We show that number of distinct {\it traces} on any $k-$ subset of $V$, is most $k.{\hat \alpha}(H)$, where ${\hat \alpha}(H)$ is the {\it degeneracy} of $H$. The ... More
Complex Tropical Currents, Extremality, and ApproximationsMar 28 2014To a tropical $p$-cycle $V_{\mathbb{T}}$ in $\mathbb{R}^n$, we naturally associate a normal closed and $(p,p)$-dimensional current on $(\mathbb{C}^*)^n$ denoted by $\mathscr{T}_n^p(V_{\mathbb{T}})$. Such a "tropical current" $\mathscr{T}_n^p(V_{\mathbb{T}})$ ... More
Squarefree vertex cover algebrasOct 27 2011Nov 02 2011In this paper we introduce squarefree vertex cover algebras. We study the question when these algebras coincide with the ordinary vertex cover algebras and when these algebras are standard graded. In this context we exhibit a duality theorem for squarefree ... More
A tropical approach to a generalized Hodge conjecture for positive currentsFeb 01 2015Mar 22 2017Demailly showed that the Hodge conjecture is equivalent to the statement that any (p,p)-dimensional closed current with rational cohomology class can be approximated by linear combinations of integration currents associated to subvarieties, and asked ... More
Fermat's principle in quantum gravitational opticsDec 29 2006Nov 28 2007Interactions incorporating the vacuum polarization effects in curved backgrounds modify the null cone structure in such a way that the photon trajectories would not be the space-time geodesics anymore. The gravitational birefringence introduced as a direct ... More
Quantum gravitational optics in the field of a gravitomagnetic monopoleJul 29 2006Dec 26 2006Vacuum polarization in QED in a background gravitational field induces interactions which {\it effectively} modify the classical picture of light rays as the null geodesics of spacetime. After a short introduction on the main aspects of the quantum gravitational ... More
A tropical approach to the strongly positive Hodge conjectureFeb 01 2015Demailly showed that the Hodge conjecture is equivalent to the statement that any (p,p)-dimensional closed current with rational cohomology class can be approximated by linear combinations of integration currents associated to subvarieties, and asked ... More
Partial Radon Transform and Hamburger moment completion in $\mathbb{R}^2$Nov 08 2015The Radon transform is one of the most powerful tools for reconstructing data from a series of projections. Reconstruction of Radon transform with missing data can be closely related to reconstruction of a function from moment sequences with missing terms. ... More
Holographic Phase Transition to Topological DyonsJul 22 2010Oct 20 2010The dynamical stability of a Julia-Zee solution in the AdS background in a four dimensional Einstein-Yang-Mills-Higgs theory is studied. We find that the model with a vanishing scalar field develops a non-zero value for the field at a certain critical ... More
A Two-Species Exclusion Model With Open Boundaries: A use of q-deformed algebraApr 20 2000In this paper we study an one-dimensional two-species exclusion model with open boundaries. The model consists of two types of particles moving in opposite directions on an open lattice. Two adjacent particles swap their positions with rate p and at the ... More
Treo: Textual Syntax for Reo ConnectorsJun 26 2018Reo is an interaction-centric model of concurrency for compositional specification of communication and coordination protocols. Formal verification tools exist to ensure correctness and compliance of protocols specified in Reo, which can readily be (re)used ... More
BEP Enhancement for Semi-Femtocell MIMO Systems Employing SC-QICs and OSTBCsJul 03 2017In mobile cellular networks, it is estimated that more than 60% of voice and data services occur indoors. Therefore, cellular network operators have shown an unprecedented interest in research on femtocell systems from various aspects to extend the indoor ... More
Axial Anomaly in Noncommutative QED on R^4Feb 17 2000May 30 2001The axial anomaly of the noncommutative U(1) gauge theory is calculated by a number of methods and compared with the commutative one. It is found to be given by the corresponding Chern class.
Ensuring Privacy with Constrained Additive Noise by Minimizing Fisher InformationAug 28 2018The problem of preserving the privacy of individual entries of a database when responding to linear or nonlinear queries with constrained additive noise is considered. For privacy protection, the response to the query is systematically corrupted with ... More
Ray-tracing and Interferometry in Schwarzschild GeometryJan 13 2010Nov 20 2011Here, we investigate the possible optical anisotropy of vacuum due to gravitational field. In doing this, we provide sufficient evidence from direct coordinate integration of the null-geodesic equations obtained from the Lagrangian method, as well as ... More
Basis functions for solution of non-homogeneous wave equationDec 02 2012Feb 19 2013In this note we extend the Differential Transfer Matrix Method (DTMM) for a second-order linear ordinary differential equation to the complex plane. This is achieved by separation of real and imaginary parts, and then forming a system of equations having ... More
Optical Modulation by Conducting InterfacesNov 04 2012Jan 08 2013We analyze the interaction of a propagating guided electromagnetic wave with a quantum well embedded in a dielectric slab waveguide. First, we design a quantum well based on InAlGaAs compounds with the transition energy of 0.8eV corresponding to a wavelength ... More
Estimation of the sample covariance matrix from compressive measurementsDec 30 2015Aug 19 2016This paper focuses on the estimation of the sample covariance matrix from low-dimensional random projections of data known as compressive measurements. In particular, we present an unbiased estimator to extract the covariance structure from compressive ... More
Syntactic Dependency Representations in Neural Relation ClassificationMay 28 2018We investigate the use of different syntactic dependency representations in a neural relation classification task and compare the CoNLL, Stanford Basic and Universal Dependencies schemes. We further compare with a syntax-agnostic approach and perform ... More
Tricritical transition in the classical XY model on Kagomé lattice under local anisotropyJun 15 2008Using mean-field theory and high resolution Monte Carlo simulation technique based on multi-histogram method, we have investigated the critical properties of an antiferromagnetic XY model on the 2D Kagom\'e lattice, with single ion easy-axes anisotropy. ... More
Quantum Mechanics of Proca FieldsMay 12 2008May 16 2009We construct the most general physically admissible positive-definite inner product on the space of Proca fields. Up to a trivial scaling this defines a five-parameter family of Lorentz invariant inner products that we use to construct a genuine Hilbert ... More
Monte Carlo simulation of an strongly coupled XY model in three dimensionsOct 01 2005Many experimental studies, over the past two decades, have constantly reported a novel critical behavior for the transition from Smectic-A phase of liquid crystals to Hexatic-B phase with non-XY critical exponents. However according to symmetry arguments ... More
Emergence of hexatic and long-range herringbone order in two-dimensional smectic liquid crystals : A Monte Carlo studyOct 01 2005Using a high resolution Monte Carlo simulation technique based on multi-histogram method and cluster-algorithm, we have investigated critical properties of a coupled XY model, consists of a six-fold symmetric hexatic and a three-fold symmetric herringbone ... More
Shock in a Branching-Coalescing Model with Reflecting BoundariesNov 10 2003Jan 22 2004A one-dimensional branching-coalescing model is considered on a chain of length L with reflecting boundaries. We study the phase transitions of this model in a canonical ensemble by using the Yang-Lee description of the non-equilibrium phase transitions. ... More
Convexity of complements of tropical varieties, and approximations of currentsNov 06 2017Sep 11 2018The goal of this note is to affirm a local version of the conjecture of Nisse--Sottile [NS16] on higher convexity of complements of tropical varieties, while providing a family of counter-examples for the global Nisse--Sottle conjecture in any codimension ... More
Positive definite Hankel matrix completions and Hamburger moment completionsSep 21 2015In this paper we give solutions to Hamburger moment problems with missing entries. The problem of completing partial positive sequences is considered. The main result is a characterization of positive definite completable patterns, namely patterns that ... More
Acoustic Nonreciprocity in Coriolis Mean Flow SystemsMay 27 2017One way to break acoustic reciprocity is to have a moving wave propagation medium. If the acoustic wave vector and the moving fluid velocity are collinear we can use the wave vector shift caused by the fluid flow to break reciprocity. In this paper we ... More
Induction of Non-Monotonic Logic Programs to Explain Boosted Tree Models Using LIMEAug 02 2018Nov 09 2018We present a heuristic based algorithm to induce \textit{nonmonotonic} logic programs that will explain the behavior of XGBoost trained classifiers. We use the technique based on the LIME approach to locally select the most important features contributing ... More
Heuristic Based Induction of Answer Set Programs: From Default theories to combinatorial problemsFeb 18 2018Significant research has been conducted in recent years to extend Inductive Logic Programming (ILP) methods to induce Answer Set Programs (ASP). These methods perform an exhaustive search for the correct hypothesis by encoding an ILP problem instance ... More
On the size-Ramsey number of cyclesJan 25 2017For given graphs $G_1,\ldots,G_k$, the size-Ramsey number $\hat{R}(G_1,\ldots,G_k)$ is the smallest integer $m$ for which there exists a graph $H$ on $m$ edges such that in every $k$-edge coloring of $H$ with colors $1,\ldots,k$, $ H $ contains a monochromatic ... More
Complexity Growth Following Multiple ShocksSep 13 2018Jan 29 2019In this paper by making use of the "Complexity=Action" proposal, we study the complexity growth after shock waves in holographic field theories. We consider both double black hole-Vaidya and AdS-Vaidya with multiple shocks geometries. We find that the ... More
Zero Temperature Phase Diagram of the Classical Kane-Mele-Heisenberg ModelApr 10 2013Jun 28 2013The classical phase diagram of the Kane-Mele-Heisenberg model is obtained by three complementary methods: Luttinger-Tisza, variational minimization, and the iterative minimization method. Six distinct phases were obtained in the space of the couplings. ... More
Effective dynamics of a conditioned generalized linear Glauber modelFeb 12 2019In order to study the stochastic Markov processes conditioned on a specific value of a time-integrated observable, the concept of ensembles of trajectories has been recently used extensively. In this paper, we consider a generic reaction-diffusion process ... More
Geometric Nonlinear Controls for Multiple Cooperative Quadrotor UAVs Transporting a Rigid BodyAug 16 2015This dissertation presents nonlinear tracking control systems for quadrotor unmanned aerial vehicles (UAV) under the influence of uncertainties. Assuming that there exist unstructured disturbances in the translational dynamics and the attitude dynamics, ... More
Multiple Shocks in a Driven Diffusive System with Two Species of ParticlesApr 05 2005A one-dimensional driven diffusive system with two types of particles and nearest neighbors interactions has been considered on a finite lattice with open boundaries. The particles can enter and leave the system from both ends of the lattice and there ... More
Estimation of the sample covariance matrix from compressive measurementsDec 30 2015Apr 28 2017This paper focuses on the estimation of the sample covariance matrix from low-dimensional random projections of data known as compressive measurements. In particular, we present an unbiased estimator to extract the covariance structure from compressive ... More
Bose-Einstein condensation and a two-dimensional walk modelJan 09 2011Mar 08 2011We introduce a two-dimensional walk model in which a random walker can only move on the first quarter of a two-dimensional plane. We calculate the partition function of this walk model using a transfer matrix method and show that the model undergoes a ... More
First Order Phase Transition in a Reaction-Diffusion Model With Open Boundary: The Yang-Lee Theory ApproachJan 22 2003May 31 2003A coagulation-decoagulation model is introduced on a chain of length L with open boundary. The model consists of one species of particles which diffuse, coagulate and decoagulate preferentially in the leftward direction. They are also injected and extracted ... More
Anomaly and Nonplanar Diagrams in Noncommutative Gauge TheoriesSep 28 2000Oct 20 2001Anomalies arising from nonplanar triangle diagrams of noncommutative gauge theory are studied. Local chiral gauge anomalies for both noncommutative U(1) and U(N) gauge theories with adjoint matter fields are shown to vanish. For noncommutative QED with ... More
An Achievable Rate-Distortion Region for the Multiple Descriptions ProblemFeb 10 2014A multiple-descriptions (MD) coding strategy is proposed and an inner bound to the achievable rate-distortion region is derived. The scheme utilizes linear codes. It is shown in two different MD set-ups that the linear coding scheme achieves a larger ... More
Approximate Noether Symmetries from Lagrangian for Plane Symmetric SpacetimesNov 07 2014Noether symmetries from geodetic Lagrangian for time-conformal plane symmetric spacetime are presented. Here, time conformal factor is used to find the approximate Noether symmetries. This is a generalization of the idea discussed by I. Hussain and A. ... More
Phase determination in spin-polarized neutron specular reflectometry by using a magnetic substrateOct 03 2004The scattering length density profile for a thin film structure can be determined uniquely if both modulus and phase of the reflection coefficient is known. Here, we describe a method for recovering the phase information which utilize a magnetic substrate ... More
Induction of Non-Monotonic Rules From Statistical Learning Models Using High-Utility Itemset MiningMay 24 2019May 29 2019We present a fast and scalable algorithm to induce non-monotonic logic programs from statistical learning models. We reduce the problem of search for best clauses to instances of the High-Utility Itemset Mining (HUIM) problem. In the HUIM problem, feature ... More
Analytical Solution to Improper Integral of Divergent Power Functions Using The Riemann Zeta FunctionMay 26 2018May 29 2018This paper presents an analytical closed-form solution to improper integral $\mu(r)=\int_0^{\infty} x^r dx$, where $r \geq 0$. The solution technique is based on splitting the improper integral into an infinite sum of definite integrals with successive ... More
Emergence of Molecular Chirality by Vibrational Raman ScatteringNov 15 2013In this study, we apply the monitoring master equation describing decoherence of internal states to an optically active molecule prepared in a coherent superposition of nondegenerate internal states interacting with thermal photons at low temperatures. ... More
Optimal Two-Stage Programming for Integration of PHEV Parking Lots in Industrial MicrogridsNov 11 2017With the progressive exhaustion of fossil energy and the enhanced awareness of environmental protection, more attention is being paid to plug in hybrid electric vehicles. Inappropriate siting and sizing of plug in hybrid electric vehicles parking lots ... More
On Effective Stochastic Generators for Conditioned Dynamics at an Atypical Reaction-Diffusion CurrentAug 18 2015Nov 24 2015We consider the fluctuations of a time-integrated particle current around an atypical value in a generic stochastic Markov process involving classical particles with two-site interaction and hardcore repulsion on a finite one-dimensional lattice with ... More
Connection between matrix-product states and superposition of Bernoulli shock measuresOct 02 2008Oct 09 2008We consider a generalized coagulation-decoagulation system on a one-dimensional discrete lattice with reflecting boundaries. It is known that a Bernoulli shock measure with two shock fronts might have a simple random-walk dynamics, provided that some ... More
On the Sub-optimality of Single-Letter Coding over NetworksMay 01 2017In this paper, we establish a new bound tying together the effective length and the maximum correlation between the outputs of an arbitrary pair of Boolean functions which operate on two sequences of correlated random variables. We derive a new upper ... More
On the Sub-optimality of Single-letter Coding in Multi-terminal CommunicationsFeb 05 2017We investigate binary block-codes (BBC). A BBC is defined as a vector of Boolean functions. We consider BBCs which are generated randomly, and using single-letter distributions. We characterize the vector of dependency spectrums of these BBCs. We use ... More
On the Correlation between Boolean Functions of Sequences of Random VariablesFeb 04 2017In this paper, we establish a new inequality tying together the effective length and the maximum correlation between the outputs of an arbitrary pair of Boolean functions which operate on two sequences of correlated random variables. We derive a new upper-bound ... More
Extended Kalman Filter on SE(3) for Geometric Control of a Quadrotor UAVMay 06 2016May 09 2016An extended Kalman filter (EKF) is developed on the special Euclidean group, SE(3) for geometric control of a quadrotor UAV. It is obtained by performing an extensive linearization on SE(3) to estimate the state of the quadrotor from noisy measurements. ... More
Exactly solvable spin chain models corresponding to BDI class of topological superconductorsJan 11 2016Apr 07 2016We present an exactly solvable extension of the quantum XY chain with longer range multi-spin interactions. Topological phase transitions of the model are classified in terms of the number of Majorana zero modes which are in turn related to an integer ... More
On the origin of the central 1" hole in the stellar disk of Sgr A* and the Fermi gamma-ray bubblesJan 31 2014Apr 17 2014The supermassive black hole Sgr A* at the center of the Galaxy is surrounded by two misaligned disks of young, massive stars extending from ~0.04 to 0.4 pc. The stellar surface density increases as ~ r^-2 towards Sgr A* but is truncated within 1" (0.04pc). ... More
Method for Undershoot-Less Control of Non-Minimum Phase Plants Based on Partial Cancellation of the Non-Minimum Phase Zero: Application to Flexible-Link RobotsDec 31 2013As a well understood classical fact, non- minimum phase zeros of the process located in a feedback connection cannot be cancelled by the corresponding poles of controller since such a cancellation leads to internal instability. This impossibility of cancellation ... More
The Origin of Keplerian Megamaser DisksApr 17 2012Several examples of thin, Keplerian, sub-parsec megamaser disks have been discovered in the nuclei of active galaxies and used to precisely determine the mass of their host black holes. We show that there is an empirical linear correlation between the ... More
Multiple-transit paths and density correlation functions in PASEPJun 09 2010We consider the partially asymmetric simple exclusion process (PASEP) when its steady-state probability distribution function can be written in terms of a linear superposition of product measures with a finite number of shocks. In this case the PASEP ... More
Effective dynamics of a conditioned generalized linear Glauber modelFeb 12 2019Feb 14 2019In order to study the stochastic Markov processes conditioned on a specific value of a time-integrated observable, the concept of ensembles of trajectories has been recently used extensively. In this paper, we consider a generic reaction-diffusion process ... More
Effective Stochastic Generator with Site-dependent InteractionsOct 28 2017It is known that the stochastic generators of effective processes associated with the unconditioned dynamics of rare events might consist of non-local interactions; however, it can be shown that there are special cases for which these generators can include ... More
An Achievable Rate-Distortion Region for Multiple Descriptions Source Coding Based on Coset CodesFeb 05 2016We consider the problem of multiple descriptions (MD) source coding and propose new coding strategies involving both unstructured and structured coding layers. Previously, the most general achievable rate-distortion (RD) region for the $l$-descriptions ... More
Ellipsoidal cones in normed vector spacesJan 29 2015We give two characterizations of cones over ellipsoids in real normed vector spaces. Let $C$ be a closed convex cone with nonempty interior such that $C$ has a bounded section of codimension $1$. We show that $C$ is a cone over an ellipsoid if and only ... More
Turbulent Origin of the Galactic-Center Magnetic Field: Nonthermal Radio FilamentsDec 14 2005A great deal of study has been carried out over the last twenty years on the origin of the magnetic activity in the Galactic center. One of the most popular hypotheses assumes milli-Gauss magnetic field with poloidal geometry, pervading the inner few ... More
Current fluctuations in a stochastic system of classical particles with next-nearest-neighbor interactionsJun 03 2019A 1D totally asymmetric exclusion process consisting of classical particles with next-nearest-neighbor interactions has been considered on a discrete lattice with a ring geometry. Using large deviation techniques, we have investigated fluctuations of ... More
A Randomized Approach to Efficient Kernel ClusteringAug 26 2016Sep 08 2016Kernel-based K-means clustering has gained popularity due to its simplicity and the power of its implicit non-linear representation of the data. A dominant concern is the memory requirement since memory scales as the square of the number of data points. ... More
A Randomized Approach to Efficient Kernel ClusteringAug 26 2016Dec 02 2016Kernel-based K-means clustering has gained popularity due to its simplicity and the power of its implicit non-linear representation of the data. A dominant concern is the memory requirement since memory scales as the square of the number of data points. ... More
On the global existence solution for a chemotaxis modelJun 24 2013Jul 03 2013This paper has been withdrawn by the authors. We consider the attraction-repulsion chemotaxis system (3 complicated PDEs system) under homogeneous Neumann boundary conditions in a bounded domain {\Omega} with smooth boundary, then the classical solutions ... More
Adaptive Control Design under Structured Model Information Limitation: A Cost-Biased Maximum-Likelihood ApproachAug 11 2012Jul 22 2014Networked control strategies based on limited information about the plant model usually results in worse closed-loop performance than optimal centralized control with full plant model information. Recently, this fact has been established by utilizing ... More
Perturbative Treatment of Quantum to Classical Transition in Chiral Molecules: Dilute Phase vs. Condensed PhaseJan 02 2017We examine the dynamics of chiral states of chiral molecules with high tunneling rates in dilute and condensed phases in the context of time-dependent perturbation theory. The chiral molecule is effectively described by an asymmetric double-well potential, ... More
A Study of Truck Platooning Incentives Using a Congestion GameOct 21 2013Jan 21 2014We introduce an atomic congestion game with two types of agents, cars and trucks, to model the traffic flow on a road over various time intervals of the day. Cars maximize their utility by finding a trade-off between the time they choose to use the road, ... More
Efficient Solvers for Sparse Subspace ClusteringApr 17 2018Sparse subspace clustering (SSC) is a popular method in machine learning and computer vision for clustering $n$ data points that lie near a union of low-dimensional linear or affine subspaces. The standard models introduced by Elhamifar and Vidal express ... More
Improved Fixed-Rank Nyström Approximation via QR Decomposition: Practical and Theoretical AspectsAug 08 2017The Nystr\"om method is a popular technique for computing fixed-rank approximations of large kernel matrices using a small number of landmark points. In practice, to ensure high quality approximations, the number of landmark points is chosen to be greater ... More
Stabilization of a Rigid Body Payload with Multiple Cooperative QuadrotorsNov 06 2015This paper presents the full dynamics and control of arbitrary number of quadrotor unmanned aerial vehicles (UAV) transporting a rigid body. The rigid body is connected to the quadrotors via flexible cables where each flexible cable is modeled as a system ... More
Dynamics and Control of Quadrotor UAVs Transporting a Rigid Body Connected via Flexible CablesJan 20 2015This paper is focused on the dynamics and control of arbitrary number of quadrotor UAVs transporting a rigid body payload. The rigid body payload is connected to quadrotors via flexible cables where each flexible cable is modeled as a system of serially-connected ... More
Stochastic modeling of gene expression: application of ensembles of trajectoriesMay 25 2019It is well established that gene expression can be modeled as a Markovian stochastic process and hence proper observables might be subjected to large fluctuations and rare events. Since dynamics is often more than statics, one can work with ensembles ... More
Spin Photonics in 3D Whispering Gallery Mode ResonatorsMar 17 2019Whispering gallery modes are known for having orbital angular momentum, however the interplay of local spin density, orbital angular momentum, and the near-field interaction with quantum emitters is much less explored. Here, we study the spin-orbital ... More
Modification of the Elite Ant System in Order to Avoid Local Optimum Points in the Traveling Salesman ProblemFeb 07 2012This article presents a new algorithm which is a modified version of the elite ant system (EAS) algorithm. The new version utilizes an effective criterion for escaping from the local optimum points. In contrast to the classical EAC algorithms, the proposed ... More
Quantum phase diagram of $J_1-J_2$ Heisenberg $S=1/2$ antiferromagnet in honeycomb lattice: a modified spin wave studyMar 29 2016Using modified spin wave (MSW) method, we study the $J_1-J_2$ Heisenberg model with first and second neighbor antiferromagnetic exchange interactions. For symmetric $S=1/2$ model, with the same couplings for all the equivalent neighbors, we find three ... More
Optimal State Estimation with Measurements Corrupted by Laplace NoiseSep 01 2016Optimal state estimation for linear discrete-time systems is considered. Motivated by the literature on differential privacy, the measurements are assumed to be corrupted by Laplace noise. The optimal least mean square error estimate of the state is approximated ... More