Results for "Sankeerth Rao"

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The independence number of the Birkhoff polytope graph, and applications to maximally recoverable codesFeb 19 2017Mar 31 2017Maximally recoverable codes are codes designed for distributed storage which combine quick recovery from single node failure and optimal recovery from catastrophic failure. Gopalan et al [SODA 2017] studied the alphabet size needed for such codes in grid ... More
Communication and Memory Efficient Testing of Discrete DistributionsJun 11 2019We study distribution testing with communication and memory constraints in the following computational models: (1) The {\em one-pass streaming model} where the goal is to minimize the sample complexity of the protocol subject to a memory constraint, and ... More
Lower Bound on the Redundancy of PIR CodesMay 06 2016We prove that the redundancy of a $k$-server PIR code of dimension $s$ is $\Omega(\sqrt{s})$ for all $k \ge 3$. This coincides with a known upper bound of $O(\sqrt{s})$ on the redundancy of PIR codes. The same lower bound was proved independently by Mary ... More
Lower Bound on the Redundancy of PIR CodesMay 06 2016Feb 28 2017We prove that the redundancy of a $k$-server PIR code of dimension $s$ is $\Omega(\sqrt{s})$ for all $k \ge 3$. This coincides with a known upper bound of $O(\sqrt{s})$ on the redundancy of PIR codes. Moreover, for $k=3$ and $k = 4$, we determine the ... More
A New Upperbound for the Oblivious Transfer Capacity of Discrete Memoryless ChannelsMay 08 2014We derive a new upper bound on the string oblivious transfer capacity of discrete memoryless channels. The main tool we use is the tension region of a pair of random variables introduced in Prabhakaran and Prabhakaran (2014) where it was used to derive ... More
Probabilistic Existence of Large Sets of DesignsApr 26 2017A new probabilistic technique for establishing the existence of certain regular combinatorial structures has been introduced by Kuperberg, Lovett, and Peled (STOC 2012). Using this technique, it can be shown that under certain conditions, a randomly chosen ... More
Torus polynomials: an algebraic approach to ACC lower boundsApr 22 2018Feb 28 2019We propose an algebraic approach to proving circuit lower bounds for ACC0 by defining and studying the notion of torus polynomials. We show how currently known polynomial-based approximation results for AC0 and ACC0 can be reformulated in this framework, ... More
An Anyon PrimerSep 18 1992Jun 04 2001In this set of lectures, we give a pedagogical introduction to the subject of anyons. We discuss 1) basic concepts in anyon physics, 2) quantum mechanics of two anyon systems, 3) statistical mechanics of many anyon systems, 4) mean field approach to many ... More
Simplex-like Structures of Maximally Supersymmetric Scattering AmplitudesDec 28 2017Jun 20 2018We elaborate the two-fold simplex-like structures of tree amplitudes in planar maximally supersymmetric Yang-Mills (N=4 SYM), through its connection to a mathematical structure known as the positive Grassmannian. Exploiting the reduced Grassmannian geometry ... More
4-particle Amplituhedronics for 3-5 loopsJun 05 2018Jun 14 2018Following the direction of 1712.09990 and 1712.09994, this article continues to excavate more interesting aspects of the 4-particle amplituhedron for a better understanding of the 4-particle integrand of planar N=4 SYM to all loop orders, from the perspective ... More
Local transition gradients determine the global attributes of protein energy landscapesJan 20 2010The dynamical characterization of proteins is crucial to understand protein function. From a microscopic point of view, protein dynamics is governed by the local atomic interactions that, in turn, trigger the functional conformational changes. Unfortunately, ... More
A Theory of Market EfficiencyFeb 09 2017We introduce a mathematical theory called market connectivity that gives concrete ways to both measure the efficiency of markets and find inefficiencies in large markets. The theory leads to new methods for testing the famous efficient markets hypothesis ... More
The Littlewood-Offord Problem for Markov ChainsApr 30 2019The celebrated Littlewood-Offord problem asks for an upper bound on the probability that the random variable $\epsilon_1 v_1 + \cdots + \epsilon_n v_n$ lies in the Euclidean unit ball, where $\epsilon_1, \ldots, \epsilon_n \in \{-1, 1\}$ are independent ... More
Positivity, Grassmannian Geometry and Simplex-like Structures of Scattering AmplitudesSep 27 2016This article revisits and elaborates the significant role of positive geometry of momentum twistor Grassmannian for planar N=4 SYM scattering amplitudes. First we establish the fundamentals of positive Grassmannian geometry for tree amplitudes. Then we ... More
Positivity, Grassmannian Geometry and Simplex-like Structures of Scattering AmplitudesSep 27 2016Jul 16 2018This article revisits and elaborates the significant role of positive geometry of momentum twistor Grassmannian for planar N=4 SYM scattering amplitudes. First we establish the fundamentals of positive Grassmannian geometry for tree amplitudes. Then we ... More
Soft Theorem of N=4 SYM in Grassmannian FormulationOct 19 2014Feb 19 2015Inspired by the new soft theorem in gravity by Cachazo and Strominger, the soft theorem for color-ordered Yang-Mills amplitudes has also been identified by Casali. In this note, the same content of N=4 SYM using the Grassmannian formulation is studied. ... More
Exact Analytic Results for Composite Fermions in a Rajaraman-Sondhi like formulationDec 23 1997Dec 25 1997We obtain the exact spectrum and the unique ground state of two composite fermions (in a Rajaraman - Sondhi like formulation) in an external magnetic field $B$. We show that the energy eigenvalues decrease with increasing angular momentum, thus making ... More
Weyl semi-metals : a short reviewMar 09 2016Mar 22 2016We begin this review with an introduction and a discussion of Weyl fermions as emergent particles in condensed matter systems, and explain how high energy phenomena like the chiral anomaly can be seen in low energy experiments. We then explain the current ... More
The impact of upper tropospheric friction and Gill-type heating on the location and strength of the Tropical Easterly Jet: Idealized physics in a dry Atmospheric General Circulation ModelMay 19 2015Jun 24 2015An atmospheric general circulation model (AGCM) with idealized and complete physics has been used to evaluate the Tropical Easterly Jet (TEJ) jet. In idealized physics, the role of upper tropospheric friction has been found to be important in getting ... More
Improved Lower Bounds for the Restricted Isometry Property of Subsampled Fourier MatricesMar 28 2019Let $A$ be an $N \times N$ Fourier matrix over $\mathbb{F}_p^{\log{N}/\log{p}}$ for some prime $p$. We improve upon known lower bounds for the number of rows of $A$ that must be sampled so that the resulting matrix $M$ satisfies the restricted isometry ... More
An Algebra of Fault ToleranceJul 20 2009Every system of any significant size is created by composition from smaller sub-systems or components. It is thus fruitful to analyze the fault-tolerance of a system as a function of its composition. In this paper, two basic types of system composition ... More
Non-linear sigma model approach to quantum spin chainsDec 05 2005We introduce and motivate the study of quantum spin chains on a one-dimensional lattice. We classify the varieties of methods that have been used to study these models into three categories, - a) exact methods to study specific models b) field theories ... More
MITOS-RCNN: A Novel Approach to Mitotic Figure Detection in Breast Cancer Histopathology Images using Region Based Convolutional Neural NetworksJul 04 2018Studies estimate that there will be 266,120 new cases of invasive breast cancer and 40,920 breast cancer induced deaths in the year of 2018 alone. Despite the pervasiveness of this affliction, the current process to obtain an accurate breast cancer prognosis ... More
The Cosmological Evolution of Quasar Damped Lyman-Alpha SystemsSep 06 2000We present results from an efficient, non-traditional survey to discover damped Lyman-alpha (DLA) absorption-line systems with neutral hydrogen column densities N(HI)>2x10^{20} atoms cm^{-2} and redshifts z<1.65. Contrary to previous studies at higher ... More
Introduction to abelian and non-abelian anyonsOct 28 2016In this set of lectures, we will start with a brief pedagogical introduction to abelian anyons and their properties. This will essentially cover the background material with an introduction to basic concepts in anyon physics, fractional statistics, braid ... More
Finding hitting times in various graphsAug 10 2012The hitting time, h_uv, of a random walk on a finite graph G, is the expected time for the walk to reach vertex v given that it started at vertex u. We present two methods of calculating the hitting time between vertices of finite graphs, along with applications ... More
Cyclicity of All Anti-NMHV and N$^2$MHV Tree Amplitudes in N=4 SYMJun 05 2018This essay proves the cyclic invariance of anti-NMHV and N$^2$MHV tree amplitudes in N=4 SYM up to any number of external particles as an interesting exercise. In the proof the two-fold simplex-like structures introduced in 1609.08627 (and reviewed in ... More
4-particle Amplituhedron at 3-loop and its Mondrian Diagrammatic ImplicationDec 28 2017Jun 14 2018This article provides a direct calculation of the 4-particle amplituhedron at 3-loop order, by introducing a set of practical tricks. After delicately rearranging each piece of this calculation, we find a suggestive connection between positivity conditions ... More
Primitive Indexes, Zsigmondy Numbers, and PrimoverizationOct 25 2018We define a primitive index of an integer in a sequence to be the index of the term with the integer as a primitive divisor. For the sequences $k^u+h^u$ and $k^u-h^u$, we discern a formula to find the primitive indexes of any composite number given the ... More
Controlled dynamics of qubits in the presence of decoherenceJun 19 2007An exactly solvable model for the decoherence of one and two-qubit states interacting with a spin-bath, in the presence of a time-dependent magnetic field is studied. The magnetic field is static along $\hat{z}$ direction and oscillatory in the transverse ... More
Nonequilibrium Thermodynamics of Chemical Reaction Networks: Wisdom from Stochastic ThermodynamicsFeb 23 2016May 30 2016We build a rigorous nonequilibrium thermodynamic description for open chemical reaction networks of elementary reactions. Their dynamics is described by deterministic rate equations satisfying mass action law. Our most general framework considers open ... More
Triangulating an exotic T quarkApr 19 2012Limits on an exotic heavy quark $T$ are broadly generalized by considering the full range of $T\rightarrow Wb, th$ or $tZ$ branching ratios. We combine results of specific $T\rightarrow tZ$ and $T\rightarrow Wb$ searches with limits on various combinations ... More
The Impact of Orography and Latent Heating on the Location of the Tropical Easterly JetAug 01 2013The Tropical Easterly Jet (TEJ) is a prominent atmospheric circulation feature observed during the Asian Summer Monsoon. It is generally assumed that Tibet is an essential ingredient in determining the location of the TEJ. However studies have also suggested ... More
Duality between normal and superconducting junctions of multiple quantum wiresJul 06 2008Oct 15 2008We study junctions of single-channel spinless Luttinger liquids using bosonisation. We generalize earlier studies by allowing the junction to be superconducting and find new charge non-conserving low energy fixed points. We establish the existence of ... More
Interference AutomataJan 22 2007We propose a computing model, the Two-Way Optical Interference Automata (2OIA), that makes use of the phenomenon of optical interference. We introduce this model to investigate the increase in power, in terms of language recognition, of a classical Deterministic ... More
Generalized Counters and Reversal ComplexityOct 25 2004Jun 27 2006We generalize the definition of a counter and counter reversal complexity and investigate the power of generalized deterministic counter automata in terms of language recognition.
Emergent Structures in an Active Polar Fluid : dynamics of shape, scattering and mergerApr 30 2016Spatially localised defect structures emerge spontaneously in a hydrodynamic description of an active polar fluid comprising polar 'actin' filaments and 'myosin' motor proteins that (un)bind to filaments and exert active contractile stresses. These emergent ... More
Nonequilibrium phase transitions in active contractile polar filamentsJan 18 2012We study the patterning and fluctuations of a collection of active contractile polar filaments on a two dimensional substrate, using a continuum description in the presence of athermal noise, parameterised by an active temperature $T_A$. The steady states ... More
Dynamics of Ordering of Isotropic MagnetsMar 03 1999We study the dynamics of ordering of the nonconserved and conserved Heisenberg magnet. The dynamics consists of two parts - an irreversible dissipation into a heat bath and a reversible precession induced by a torque due to the local molecular field. ... More
Arrested States of SolidsOct 01 1999Solids produced as a result of a fast quench across a freezing or a structural transition get stuck in long-lived metastable configurations of distinct morphology, sensitively dependent on the processing history. {\it Martensites} are particularly well ... More
First Passage Times and Time-Temperature-Transformation curves for MartensitesSep 02 1997Martensites are long-lived nonequilibrium structures produced following a quench across a solid state structural transition. In a recent paper (Phys. Rev. Lett. 78, 2168 (1997)), we had described a mode-coupling theory for the morphology and nucleation ... More
Anti-concentration in most directionsNov 15 2018Jan 19 2019We prove an anti-concentration bound for the inner product of two independent random vectors in the discrete cube. If, for example, $A,B$ are subsets of the cube $\{\pm 1\}^n$ with $|A| \cdot |B| \geq 2^{1.01 n}$, and $X \in A$ and $Y \in B$ are sampled ... More
Impact of Frequentist and Bayesian Methods on Survey Sampling Practice: A Selective AppraisalAug 11 2011According to Hansen, Madow and Tepping [J. Amer. Statist. Assoc. 78 (1983) 776--793], "Probability sampling designs and randomization inference are widely accepted as the standard approach in sample surveys." In this article, reasons are advanced for ... More
A Time-parallel Approach to Strong-constraint Four-dimensional Variational Data AssimilationMay 18 2015A parallel-in-time algorithm based on an augmented Lagrangian approach is proposed to solve four-dimensional variational (4D-Var) data assimilation problems. The assimilation window is divided into multiple sub-intervals that allows to parallelize cost ... More
Dear Sir or Madam, May I introduce the GYAFC Dataset: Corpus, Benchmarks and Metrics for Formality Style TransferMar 17 2018Apr 16 2018Style transfer is the task of automatically transforming a piece of text in one particular style into another. A major barrier to progress in this field has been a lack of training and evaluation datasets, as well as benchmarks and automatic metrics. ... More
Interplay of Floquet Lifshitz transitions and topological transitions in bilayer Dirac materialsMay 10 2018We show how transitions between different Lifshitz phases in bilayer Dirac materials with and without spin-orbit coupling can be studied by driving the system. The periodic driving is induced by a laser and the resultant phase diagram is studied in the ... More
Temperature response of the polarizable SWM4-NDP water modelNov 08 2013Introduction of polarizability in classical molecular simulations holds the promise to increase accuracy as well as prediction power to computer modeling. To introduce polarizability in a straight-forward way one strategy is based on Drude particles: ... More
X-ray Radio Correlation In Black Hole SourcesNov 13 2006We examine the X-ray - radio correlation in Galactic black hole sources. We highlight some of the results which extend the flux-flux relations to sources with very high accretion rates. Some of the recent results indicate that the synchrotron process ... More
Multilateral Index Number Systems for International Price Comparisons: Properties, Existence and UniquenessNov 10 2018Dec 14 2018Over the past five decades a number of multilateral index number systems have been proposed for spatial and cross-country price comparisons. These multilateral indexes are usually expressed as solutions to systems of linear or nonlinear equations. In ... More
Approximation properties by generalized Baskakov Kantorovich Stancu type operatorsAug 05 2015In this paper, we introduce generalized Baskakov Kantorovich Stancu type operators and investigate direct result, local approximation and weighted approximation properties of these operators. Modulus of continuity, second modulus of continuity, Peeters ... More
Partial classification of modules for Lie-algebra of diffeomorphisms of d-dimensional torusDec 01 2003May 18 2004We consider the Lie-algebra of the group of diffeomorphisms of d-dimensional torus which is also known to be the algebra of derivations on a Laurent polynomial ring A in d commuting variables denoted by DerA. Larsson has constructed a large class of DerA ... More
An aperiodic set of 11 Wang tilesJun 22 2015Mar 13 2019We present a new aperiodic tile set containing 11 Wang tiles on 4 colors, and show that this tile set is minimal in the sense that no Wang set with less than 11 tiles is aperiodic, and no Wang set with less than 4 colors is aperiodic. This gives a final ... More
Range of Berezin TransformMar 20 2010Let $\ds dA=\frac{dxdy}\pi$ denote the normalized Lebesgue area measure on the unit disk $\disk$ and $u$, a summable function on $\disk$. $$B(u)(z)=\int_\disk u(\zeta)\frac{(1-|z|^2)^2}{|1-\zeta\oln z|^4}dA(\zeta)$$ is called the Berezin transform of ... More
Geometric progressions in syndetic setsAug 28 2018Apr 28 2019In order to investigate multiplicative structures in additively large sets, Beiglb\"{o}ck et al. raised a significant open question as to whether or not every subset of the natural numbers with bounded gaps (syndetic set) contains arbitrarily long geometric ... More
Lipschitz equivalence of fractals and finite state automatonSep 14 2016The study of Lipschitz equivalence of fractals is a very active topic in recent years. Most of the studies in literature concern totally disconnected fractals. In this paper, using finite state automata, we construct a bi-Lipschitz map between two fractal ... More
Higher dimensional Frobenius problem and Lipschitz equivalence of Cantor setsNov 26 2014The higher dimensional Frobenius problem was introduced by a preceding paper [Fan, Rao and Zhang, Higher dimensional Frobenius problem: maximal saturated cones, growth function and rigidity, Preprint 2014]. %the higher dimensional Frobenius problem was ... More
Where are the Fermi Lines Coming From?Oct 17 2012We estimate the spatial locations of sources of the the observed features in the Fermi-LAT photon spectrum at $E_\gamma=110$ and $E_\gamma=130$ GeV. We determine whether they are consistent with emission from a single source, as would be expected in their ... More
Some Observational Aspects of R Coronae Borealis StarsDec 24 2007Some of the observational aspects related to the evolutionary status and dust production in R Cor Bor stars are discussed. Recent work regarding the surface abundances, stellar winds and evidence for dust production in these high luminosty hydrogen deficient ... More
Two Modes of Solid State Nucleation - Ferrites, Martensites and Isothermal Transformation CurvesJul 05 2001Aug 17 2001When a crystalline solid such as iron is cooled across a structural transition, its final microstructure depends sensitively on the cooling rate. For instance, an adiabatic cooling across the transition results in an equilibrium `ferrite', while a rapid ... More
Bounding Run-Times of Local Adiabatic AlgorithmsJan 20 2007A common trick for designing faster quantum adiabatic algorithms is to apply the adiabaticity condition locally at every instant. However it is often difficult to determine the instantaneous gap between the lowest two eigenvalues, which is an essential ... More
Dynamics of Ordering of Heisenberg Spins with Torque --- Nonconserved Case. ISep 27 1997We study the dynamics of ordering of a nonconserved Heisenberg magnet. The dynamics consists of two parts --- an irreversible dissipation into a heat bath and a reversible precession induced by a torque due to the local molecular field. For quenches to ... More
Energy-Efficient Scheduling: Classification, Bounds, and AlgorithmsSep 21 2016The problem of attaining energy efficiency in distributed systems is of importance, but a general, non-domain-specific theory of energy-minimal scheduling is far from developed. In this paper, we classify the problems of energy-minimal scheduling and ... More
Failover in cellular automataMay 29 2010A cellular automata (CA) configuration is constructed that exhibits emergent failover. The configuration is based on standard Game of Life rules. Gliders and glider-guns form the core messaging structure in the configuration. The blinker is represented ... More
Geometric progressions in syndetic setsAug 28 2018In order to investigate multiplicative structures in additively large sets, Beiglb\"{o}ck et al. raised a significant open question as to whether or not every subset of the natural numbers with bounded gaps (syndetic set) contains arbitrarily long geometric ... More
Tunneling through two resonant levels: fixed points and conductancesApr 01 2004We study point contact tunneling between two leads of a Tomonaga-Luttinger liquid through two degenerate resonant levels in parallel. This is one of the simplest cases of a quantum junction problem where the Fermi statistics of the electrons plays a non-trivial ... More
The 2-domination and Roman domination numbers of grid graphsOct 30 2018May 17 2019We investigate the 2-domination number for grid graphs, that is the size of a smallest set $D$ of vertices of the grid such that each vertex of the grid belongs to $D$ or has at least two neighbours in $D$. We give a closed formula giving the 2-domination ... More
A-posteriori error estimates for inverse problemsSep 25 2014Jan 30 2015Inverse problems use physical measurements along with a computational model to estimate the parameters or state of a system of interest. Errors in measurements and uncertainties in the computational model lead to inaccurate estimates. This work develops ... More
Hierarchical RNN for Information Extraction from Lawsuit DocumentsApr 25 2018Every lawsuit document contains the information about the party's claim, court's analysis, decision and others, and all of this information are helpful to understand the case better and predict the judge's decision on similar case in the future. However, ... More
High Energy Transients: the Millisecond DomainNov 01 2017Search for high energy transients in the millisecond domain has come to the focus in recent times due to the detection of Gravitational Wave events and the identification of Fast Radio Bursts as cosmological sources. I will highlight the sensitivity limitations ... More
Automatic Music AccompanistMar 24 2018Automatic musical accompaniment is where a human musician is accompanied by a computer musician. The computer musician is able to produce musical accompaniment that relates musically to the human performance. The accompaniment should follow the performance ... More
Fast extraction of the backbone of projected bipartite networks to aid community detectionDec 07 2015Mar 21 2016This paper introduces a computationally inexpensive method of extracting the backbone of one-mode networks projected from bipartite networks. We show that the edge weights in the one-mode projections are distributed according to a Poisson binomial distribution ... More
Observing Galactic Black Hole Sources in Hard X-raysOct 01 2013Observations of Galactic black hole sources are traditionally done in the classical X-ray range (2 -- 10 keV) due to sensitivity constraints. Most of the accretion power, however, is radiated above 10 keV and the study of these sources in hard X-rays ... More
Efficient parameter sampling for Markov jump processesApr 07 2017Jun 01 2018Markov jump processes (MJPs) are continuous-time stochastic processes widely used in a variety of applied disciplines. Inference for MJPs typically proceeds via Markov chain Monte Carlo, the state-of-the-art being a uniformization-based auxiliary variable ... More
Network Flows Under Thermal RestrictionsJul 09 2016We define a \emph{thermal network}, which is a network where the flow functionality of a node depends upon its temperature. This model is inspired by several types of real-life networks, and generalizes some conventional network models wherein nodes have ... More
Avoiding two consecutive blocks of same size and same sum over $\mathbb{Z}^2$Nov 18 2015Sep 30 2016A long standing question asks whether $\mathbb{Z}$ is uniformly 2-repetitive [Justin 1972, Pirillo and Varricchio, 1994], that is, whether there is an infinite sequence over a finite subset of $\mathbb{Z}$ avoiding two consecutive blocks of same size ... More
Note on Identities Inspired by New Soft TheoremsApr 03 2016May 04 2016The new soft theorems, for both gravity and gauge amplitudes, have inspired a number of works, including the discovery of new identities related to amplitudes. In this note, we present the proof and discussion for two sets of identities. The first set ... More
The protein folding networkMar 23 2004The conformation space of a 20-residue antiparallel $\beta$-sheet peptide, sampled by molecular dynamics simulations, is mapped to a network. Conformations are nodes of the network, and the transitions between them are links. The conformation space network ... More
Complete reducibility of integrable modules for the affine Lie(super) algebrasJan 07 2003We prove complete reducibility for an integrable module for an affine Lie algebra where the canonical central element acts non-trivially. We further prove that integrable modules does not exists for most of the super affine Lie algebras where the center ... More
Irreducible representations for Toroidal Lie algebrasDec 10 2002We study irreducible modules for Toroidal Lie-algebras with finite dimensional weight spaces. First note that Toroidal Lie-algebras have infinite dimensional center. In genaral the infinite dimensional center does not act as scalars on an irreducible ... More
A simple model for magnetic inelastic dark matter (MiDM)Dec 15 2011A simple model for magnetic inelastic dark matter (MiDM), which is a minimal extension of the standard model with right-handed neutrinos ($N_R$), a singly charged scalar ($S$) and a vector-like charged fermion ($E$), has been presented. In this framework ... More
Degradation Analysis of Probabilistic Parallel Choice SystemsApr 22 2014Degradation analysis is used to analyze the useful lifetimes of systems, their failure rates, and various other system parameters like mean time to failure (MTTF), mean time between failures (MTBF), and the system failure rate (SFR). In many systems, ... More
Lattice Boltzmann Models for Micro-tomographic Pore-spacesFeb 28 2019The lattice Boltzmann method (LBM) is a popular numerical framework to investigate single and multiphase flow though porous media. For estimation of absolute permeability based on micro-tomographic images of the porous medium, the single-relaxation time ... More
Lipschitz invariance of walk dimension on connected self-similar setsSep 14 2016Walk dimension is an important conception in analysis of fractals. In this paper we prove that the walk dimension of a connected compact set possessing an Alfors regular measure is an invariant under Lipschitz transforms. As an application, we show some ... More
Central Forests in TreesSep 02 2008A new 2-parameter family of central structures in trees, called central forests, is introduced. Minieka's $m$-center problem and McMorris's and Reid's central-$k$-tree can be seen as special cases of central forests in trees. A central forest is defined ... More
Fractional extensions of some boundary value problems in oil strataJul 13 2007In the present paper, we solve three boundary value problems related to the temperature field in oil strata -- the fractional extensions of the incomplete lumped formulation and lumped formulation in the linear case and the fractional generalization of ... More
Actionable and Political Text Classification using Word Embeddings and LSTMJul 08 2016Jul 13 2016In this work, we apply word embeddings and neural networks with Long Short-Term Memory (LSTM) to text classification problems, where the classification criteria are decided by the context of the application. We examine two applications in particular. ... More
Some approximation theoremsDec 05 2003The general theme of this note is illustrated by the following theorem: Theorem 1. Suppose $K$ is a compact set in the complex plane and 0 belongs to the boundary $\partial K$. Let ${\cal A}(K)$ denote the space of all functions $f$ on $K$ such that $f$ ... More
Henon-Heiles Hamiltonian for Coupled Upper-Hybrid and Magnetoacoutic Waves in Magnetized PlasmasJul 24 1995We show that the coupled mode equations for the stationary propagation of upper--hybrid and magnetoacoustic waves in magnetized electron--ion plasmas with negative group dispersion can be exactly derived from the generalized \Henon--Heiles Hamiltonian. ... More
Using machine learning for medium frequency derivative portfolio tradingDec 19 2015We use machine learning for designing a medium frequency trading strategy for a portfolio of 5 year and 10 year US Treasury note futures. We formulate this as a classification problem where we predict the weekly direction of movement of the portfolio ... More
An aperiodic set of 11 Wang tilesJun 22 2015A new aperiodic tile set containing 11 Wang tiles on 4 colors is presented. This tile set is minimal in the sense that no Wang set with less than 11 tiles is aperiodic, and no Wang set with less than 4 colors is aperiodic.
A model solid-state structural transformation: Tetragonal to OrthorhombicJun 05 2001We study equilibrium properties of a system of particles in two dimensions, interacting with pair and three body potentials, which undergoes a structural transition from a square to a rhombic lattice and thus constitutes a simple model for a generic tetragonal ... More
Conserved Ordering Dynamics of Heisenberg Spins with TorqueMar 02 1999We show that a torque induced by the local molecular field drives the zero-temperature ordering dynamics of a conserved Heisenberg magnet to a new fixed point, characterised by exponents z=2 and $\lambda \approx 5.15$. Numerical solutions of the Langevin ... More
Droplet Free Energy Functional for the Morphology of MartensitesMar 07 1996Martensites are metastable phases, possessing a characteristic morphology, usually formed during a fast quench accross a structural transition. We attempt to understand these morphological features using a coarsegrained free energy functional ${\cal F}[\epsilon ... More
Orthogonal samples for estimators in time seriesNov 01 2016Inference for statistics of a stationary time series often involve nuisance parameters and sampling distributions that are difficult to estimate. In this paper, we propose the method of orthogonal samples, which can be used to address some of these issues. ... More
Several special complex structures and their deformation propertiesApr 19 2016We introduce a natural map from the space of pure-type complex differential forms on a complex manifold to the corresponding one on the infinitesimal deformations of this complex manifold. By use of this map, we generalize an extension formula in a recent ... More
Spin polarised scanning tunneling probe for helical Luttinger liquidsJun 11 2010May 17 2011We propose a three terminal spin polarized stm setup for probing the helical nature of the Luttinger liquid edge state that appears in the quantum spin Hall system. We show that the three-terminal tunneling conductance strongly depends on the angle ($\theta$) ... More
Parallelization of the LBG Vector Quantization Algorithm for Shared Memory SystemsOct 26 2009This paper proposes a parallel approach for the Vector Quantization (VQ) problem in image processing. VQ deals with codebook generation from the input training data set and replacement of any arbitrary data with the nearest codevector. Most of the efforts ... More
Fairness in Combinatorial Auctioning SystemsSep 12 2008One of the Multi-Agent Systems that is widely used by various government agencies, buyers and sellers in a market economy, in such a manner so as to attain optimized resource allocation, is the Combinatorial Auctioning System (CAS). We study another important ... More
Results from bosonisation for resonant tunneling through a quantum dot in an Aharanov-Bohm ringSep 29 1999We study coherent charge tunneling through a one-dimensional interacting ring with a one-dimensional quantum dot embedded in one of its arms through bosonisation. The symmetries of the effective action explain many of the features such as phase change ... More
Damped Lyman Alpha Surveys and Statistics - A ReviewMay 23 2005The history and progress of DLA research over the past several decades is reviewed here. Larger datasets and deeper surveys, particularly over the last couple of years, have improved our knowledge of the neutral gas content and distribution in the universe ... More