Results for "Farhad Khoeini"

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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
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
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
A new separation theorem with geometric applicationsApr 20 2015Let $G=(V(G), E(G))$ be an undirected graph with a measure function $\mu$ assigning non-negative values to subgraphs $H$ so that $\mu(H)$ does not exceed the clique cover number of $H$. When $\mu$ satisfies some additional natural conditions, we study ... More
A new upper bound for the clique cover number with applicationsFeb 22 2015Let $\alpha(G)$ and $\beta(G)$, denote the size of a largest independent set and the clique cover number of an undirected graph $G$. Let $H$ be an interval graph with $V(G)=V(H)$ and $E(G)\subseteq E(H)$, and let $\phi(G,H)$ denote the maximum of ${\beta(G[W])\over ... More
Development and Analysis of Deterministic Privacy-Preserving Policies Using Non-Stochastic Information TheoryOct 26 2018Jan 23 2019A deterministic privacy metric using non-stochastic information theory is developed. Particularly, minimax information is used to construct a measure of information leakage, which is inversely proportional to the measure of privacy. Anyone can submit ... More
Large Extra Dimensions and Noncommutative Geometry in String TheoryOct 07 1999The consequences of noncommutativity of space coordinates of string theory in the proposed large extra dimension solution to the hierarchy problem are explored; in particular the large dimension stabilization and the graviton reabsorption in the brane ... More
Strong Pseudo Transitivity and Intersection GraphsJun 04 2018A directed graph $G=(V,E)$ is {\it strongly pseudo transitive} if there is a partition $\{A,E-A\}$ of $E$ so that graphs $G_1=(V,A)$ and $G_2=(V,E-A)$ are transitive, and additionally, if $ab\in A$ and $bc\in E $ implies that $ac\in E$. A strongly pseudo ... 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
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
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
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
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
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
New separation theorems and sub-exponential time algorithms for packing and piercing of fat objectsFeb 22 2015For $\cal C$ a collection of $n$ objects in $R^d$, let the packing and piercing numbers of $\cal C$, denoted by $Pack({\cal C})$, and $Pierce({\cal C})$, respectively, be the largest number of pairwise disjoint objects in ${\cal C}$, and the smallest ... More
de Broglie oscillation, rest mass and inertiaMay 13 2000The model of a relativistic free massive point particle is investigated in the context of a Hamiltonian constraint system. It is shown that de Broglie oscillation, rest mass and inertia may be described within this model of Hamiltonian constraint system. ... 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
Cutoff Function in Holographic RG FlowFeb 25 2019Using the precursor map in AdS/CFT, the renormalization group cutoff function is mapped to the dual theory. The resulting flow equations on the two sides of the duality are compared.
Taking a Lesson from Quantum Particles for Statistical Data PrivacyAug 14 2019Privacy is under threat from artificial intelligence revolution fueled by unprecedented abundance of data. Differential privacy, an established candidate for privacy protection, is susceptible to adversarial attacks, acts conservatively, and leads to ... More
Unit Incomparability Dimension and Clique Cover Width in GraphsMay 11 2017For a clique cover $C$ in the undirected graph $G$, the {\it clique cover graph} of $C$ is the graph obtained by contracting the vertices of each clique in $C$ into a single vertex. The {\it clique cover width} of $G$, denoted by $CCW(G)$, is the minimum ... More
Bounds for the Clique Cover Width of Factors of the Apex Graph of the Planar GridJun 22 2015Feb 17 2016The {\it clique cover width} of $G$, denoted by $ccw(G)$, is the minimum value of the bandwidth of all graphs that are obtained by contracting the cliques in a clique cover of $G$ into a single vertex. For $i=1,2,...,d,$ let $G_i$ be a graph with $V(G_i)=V$, ... More
Inertia as Emerging of a Hamiltonian Constraint SystemNov 07 1998The issue of inertia as opposition to acceleration of a massive point particle in Minkowski space-time is investigated in the context of a Hamiltonian constraint system. It is shown that the inertia as a locally-originating force in Minkowski space-time ... More
2D Black Holes and 2D GravityJan 18 1993\small The SL$(2,R)/U(1)$ coset model, with $U(1)$ an element of the third conjugacy class of $SL(2,R)$ subgroups, is considered. The resulting theory is seen to collapse to a one dimensional field theory of Liouville. Then the 2 dimensional black hole ... More
Algorithms For Longest Chains In Pseudo- Transitive GraphsJan 19 2017A directed acyclic graph G = (V, E) is pseudo-transitive with respect to a given subset of edges E1, if for any edge ab in E1 and any edge bc in E, we have ac in E. We give algorithms for computing longest chains and demonstrate geometric applications ... More
A Game-Theoretic Approach to Adversarial Linear Support Vector ClassificationJun 24 2019In this paper, we employ a game-theoretic model to analyze the interaction between an adversary and a classifier. There are two classes (i.e., positive and negative classes) to which data points can belong. The adversary is interested in maximizing the ... More
Discounted Differential Privacy: Privacy of Evolving Datasets over an Infinite HorizonAug 12 2019In this paper, we define discounted differential privacy, as an alternative to (conventional) differential privacy, to investigate privacy of evolving datasets, containing time series over an unbounded horizon. Evolving datasets arise in energy systems ... 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
Lensing effects in inhomogeneous cosmological modelsJan 03 2009Concepts developed in the gravitational lensing techniques such as shear, convergence, tangential and radial arcs maybe used to see how tenable inhomogeneous models proposed to explain the acceleration of the universe models are. We study the widely discussed ... More
Fermionic Tachyons as a Source of Dark EnergyJul 13 2018Jun 15 2019A model for the universe on the basis of a self interacting fermionic tachyon field is investigated here. It is shown that, devising a self interaction potential of a proper form, the fermionic tachyon field is capable of producing an accelerating expansion ... 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
Matrix Product States of Three Families of One-Dimensional Interacting Particle SystemsJan 26 2004The steady states of three families of one-dimensional non-equilibrium models with open boundaries, first proposed in [22], are studied using a matrix product formalism. It is shown that their associated quadratic algebras have two-dimensional representations, ... More
Cosmic strings interacting with dark stringsApr 29 2009Jul 14 2009Motivated by astrophysical observations of excess electronic production in the galaxy, new theoretical models of the dark matter sector have been proposed in which the Standard model couples to the dark matter sector through an attractive interaction. ... 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
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
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
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.
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
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
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
Proximal quasi-normal structure and existence of best proximity pointsJul 24 2019In this paper, we use the concept of proximal quasi-normal structure (P. Q-N. S) to study the existence of best proximity points for cyclic mappings, cyclic contractions, relatively Kannan nonexpansive mappings, as well as for orbitally nonexpansive mappings. ... 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
Preserving Privacy of Agents in Participatory-Sensing Schemes for Traffic EstimationSep 05 2016A measure of privacy infringement for agents (or participants) travelling across a transportation network in participatory-sensing schemes for traffic estimation is introduced. The measure is defined to be the conditional probability that an external ... More
Numerical Study of Phase Transition in an Exclusion Model with Parallel DynamicsMar 03 2004A numerical method based on Matrix Product Formalism is proposed to study the phase transitions and shock formation in the Asymmetric Simple Exclusion Process with open boundaries and parallel dynamics. By working in a canonical ensemble, where the total ... More
A Multi-Species Asymmetric Exclusion Model with an ImpuritySep 24 2001A multi-species generalization of the Asymmetric Simple Exclusion Process (ASEP) has been considered in the presence of a single impurity on a ring. The model describes particles hopping in one direction with stochastic dynamics and hard core exclusion ... More
Exact Solution of an Exclusion Model in the Presence of a moving ImpurityNov 01 2000We study a recently introduced model which consists of positive and negative particles on a ring. The positive (negative) particles hop clockwise (counter-clockwise) with rate 1 and oppositely charged particles may swap their positions with asymmetric ... 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
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
Quantum corrections for a black hole in an asymptotically safe gravity with higher derivativesOct 29 2011Dec 07 2011By using the quantum tunneling approach over semiclassical approximations, we study the quantum corrections to the Hawking temperature, entropy and Bekenstein-Hawking entropy-area relation for a black hole in an asymptotically safe gravity with higher ... More
Quantum Corrections for a Braneworld Black HoleFeb 24 2011Jun 25 2011By using the quantum tunneling approach over semiclassical approximations, we study the quantum corrections to the Hawking temperature, entropy and Bekenstein-Hawking entropy-area relation for a black hole lying on a brane.
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
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
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
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
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
Central Charge for 2D Gravity on AdS(2) and AdS(2)/CFT(1) CorrespondenceMay 13 2008Aug 19 2008We study 2D Maxwell-dilaton gravity on AdS(2). We distinguish two distinctive cases depending on whether the AdS(2) solution can be lifted to an AdS(3) geometry. In both cases, in order to get a consistent boundary condition we need to work with a twisted ... More
Noether symmetric classical and quantum scalar field cosmologySep 15 2011Dec 16 2011We study the evolution of a two dimensional minisuperspace cosmological model in classical and quantum levels by the Noether symmetry approach. The phase space variables turn out to correspond to the scale factor of a Friedmann-Robertson-Walker (FRW) ... More
The Application of the Yang-Lee Theory to Study a Phase Transition in a Non-Equilibrium SystemSep 24 2002Apr 24 2003We study a phase transition in a non-equilibrium model first introduced in [5], using the Yang-Lee description of equilibrium phase transitions in terms of both canonical and grand canonical partition function zeros. The model consists of two different ... More
Planar and Nonplanar Konishi Anomalies and Effective Superpotential for Noncommutative N=1 Supersymmetric U(1)Jul 17 2003Jan 20 2005The Konishi anomalies for noncommutative N=1 supersymmetric U(1) gauge theory arising from planar and nonplanar diagrams are calculated. Whereas planar Konishi anomaly is the expected \star-deformation of the commutative anomaly, nonplanar anomaly reflects ... More
Partially Asymmetric Simple Exclusion Model in the Presence of an Impurity on a RingAug 24 1999Oct 19 1999We study a generalized two-species model on a ring. The original model [1] describes ordinary particles hopping exclusively in one direction in the presence of an impurity. The impurity hops with a rate different from that of ordinary particles and can ... More
Comparing different modes of quantum state transfer in a XXZ spin chainJul 29 2014Aug 03 2014We study the information transferring ability of a spin-1/2 XXZ Hamiltonian for two different modes of state transfer, namely, the well studied attaching scenario and the recently proposed measurement induced transport. The latter one has been inspired ... More
Data Science Methodology for Cybersecurity ProjectsMar 12 2018Cyber-security solutions are traditionally static and signature-based. The traditional solutions along with the use of analytic models, machine learning and big data could be improved by automatically trigger mitigation or provide relevant awareness to ... More
Combinatorial Entropy Power Inequalities: A Preliminary Study of the Stam regionApr 04 2017Jun 29 2018We initiate the study of the Stam region, defined as the subset of the positive orthant in $\mathbb{R}^{2^n-1}$ that arises from considering entropy powers of subset sums of $n$ independent random vectors in a Euclidean space of finite dimension. We show ... More
Mutual Information as Privacy-Loss Measure in Strategic CommunicationSep 18 2015A game is introduced to study the effect of privacy in strategic communication between well-informed senders and a receiver. The receiver wants to accurately estimate a random variable. The sender, however, wants to communicate a message that balances ... 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
On the Formation of Compact Stellar Disks Around Sgr A*May 21 2008Jul 03 2008The recent identification of one or two sub-parsec disks of young, massive stars orbiting the ~4e6 solar mass black hole Sgr A* has prompted an "in-situ" scenario for star formation in disks of gas formed from a cloud captured from the Galactic center ... More
Stochastic Sensor Scheduling for Networked Control SystemsSep 24 2012Oct 15 2013Optimal sensor scheduling with applications to networked estimation and control systems is considered. We model sensor measurement and transmission instances using jumps between states of a continuous-time Markov chain. We introduce a cost function for ... More
Optimal Control Design under Limited Model Information for Discrete-Time Linear Systems with Stochastically-Varying ParametersMar 06 2012Dec 04 2013The value of plant model information available in the control design process is discussed. We design optimal state-feedback controllers for interconnected discrete-time linear systems with stochastically-varying parameters. The parameters are assumed ... More
A Scaling Relation Between Megamaser Disk Radius and Black Hole Mass in Active Galactic NucleiAug 10 2011Mar 26 2012Several 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 disk radius ... More
Equivalence of a one-dimensional driven-diffusive system and an equilibrium two-dimensional walk modelDec 14 2009It is known that a single product shock measure in some of one-dimensional driven-diffusive systems with nearest-neighbor interactions might evolve in time quite similar to a random walker moving on a one-dimensional lattice with reflecting boundaries. ... More
Carbon nanotube-copper fibers produced by electrospinning: electrical conductivity measurementsNov 19 2018Recent advances in nanotechnology have provided new materials which have the potential to surpass copper and aluminum alloys in electrical conductivity, weight and ampacity [2-6]. Among these carbon nanotubes (CNTs) stand out due to their remarkable thermal ... More
An Efficient Scenario-Based Stochastic Model for Dynamic Operational Scheduling of Community Microgrids with High Penetration RenewablesNov 11 2017The supply of electrical energy is being increasingly sourced from renewable generation resources. The variability and uncertainty of renewable generation, compared to a dispatch-able plant, is a significant dissimilarity of concern to the traditionally ... More
Current fluctuations in a stochastic system of classical particles with next-nearest-neighbor interactionsJun 03 2019Sep 10 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
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