Results for "Parikshit Gopalan"

total 194took 0.14s
Inequalities and tail bounds for elementary symmetric polynomial with applicationsFeb 14 2014Aug 10 2015We study the extent of independence needed to approximate the product of bounded random variables in expectation, a natural question that has applications in pseudorandomness and min-wise independent hashing. For random variables whose absolute value ... More
Pseudorandomness for concentration bounds and signed majoritiesNov 17 2014The problem of constructing pseudorandom generators that fool halfspaces has been studied intensively in recent times. For fooling halfspaces over the hypercube with polynomially small error, the best construction known requires seed-length O(log^2 n) ... More
The Connectivity of Boolean Satisfiability: Computational and Structural DichotomiesSep 13 2006Oct 03 2007Boolean satisfiability problems are an important benchmark for questions about complexity, algorithms, heuristics and threshold phenomena. Recent work on heuristics, and the satisfiability threshold has centered around the structure and connectivity of ... More
Polynomials that Sign Represent Parity and Descartes' Rule of SignsFeb 26 2007A real polynomial $P(X_1,..., X_n)$ sign represents $f: A^n \to \{0,1\}$ if for every $(a_1, ..., a_n) \in A^n$, the sign of $P(a_1,...,a_n)$ equals $(-1)^{f(a_1,...,a_n)}$. Such sign representations are well-studied in computer science and have applications ... More
Making the long code shorter, with applications to the Unique Games ConjectureNov 02 2011The long code is a central tool in hardness of approximation, especially in questions related to the unique games conjecture. We construct a new code that is exponentially more efficient, but can still be used in many of these applications. Using the ... More
Stable and Consistent Membership at Scale with RapidMar 09 2018We present the design and evaluation of Rapid, a distributed membership service. At Rapid's core is a scheme for multi-process cut detection (CD) that revolves around two key insights: (i) it suspects a failure of a process only after alerts arrive from ... More
Maximally Recoverable Codes for Grid-like TopologiesMay 18 2016Sep 20 2016The explosion in the volumes of data being stored online has resulted in distributed storage systems transitioning to erasure coding based schemes. Yet, the codes being deployed in practice are fairly short. In this work, we address what we view as the ... More
Hillview: A trillion-cell spreadsheet for big dataJul 10 2019Hillview is a distributed spreadsheet for browsing very large datasets that cannot be handled by a single machine. As a spreadsheet, Hillview provides a high degree of interactivity that permits data analysts to explore information quickly along many ... More
Locally Testable Codes and Cayley GraphsAug 23 2013We give two new characterizations of ($\F_2$-linear) locally testable error-correcting codes in terms of Cayley graphs over $\F_2^h$: \begin{enumerate} \item A locally testable code is equivalent to a Cayley graph over $\F_2^h$ whose set of generators ... More
Efficient Anomaly Detection via Matrix SketchingApr 09 2018Nov 27 2018We consider the problem of finding anomalies in high-dimensional data using popular PCA based anomaly scores. The naive algorithms for computing these scores explicitly compute the PCA of the covariance matrix which uses space quadratic in the dimensionality ... More
List Decoding Tensor Products and Interleaved CodesNov 26 2008We design the first efficient algorithms and prove new combinatorial bounds for list decoding tensor products of codes and interleaved codes. We show that for {\em every} code, the ratio of its list decoding radius to its minimum distance stays unchanged ... More
Pseudorandomness via the discrete Fourier transformJun 14 2015Nov 18 2015We present a new approach to constructing unconditional pseudorandom generators against classes of functions that involve computing a linear function of the inputs. We give an explicit construction of a pseudorandom generator that fools the discrete Fourier ... More
Public projects, Boolean functions and the borders of Border's theoremApr 29 2015Border's theorem gives an intuitive linear characterization of the feasible interim allocation rules of a Bayesian single-item environment, and it has several applications in economic and algorithmic mechanism design. All known generalizations of Border's ... More
Polynomial-Time Approximation Schemes for Knapsack and Related Counting Problems using Branching ProgramsAug 18 2010We give a deterministic, polynomial-time algorithm for approximately counting the number of {0,1}-solutions to any instance of the knapsack problem. On an instance of length n with total weight W and accuracy parameter eps, our algorithm produces a (1 ... More
Some insights in the structure of correlation functions in Liouville and Toda field theoriesDec 16 2014We discuss some aspects of Liouville field theory, starting from operator equation of motion in presence of two screening charges and re-derive the dual zero mode Schwinger Dyson equations for the two screening charges from the path integral. Using functional ... More
Schwinger-Dyson approach to Liouville Field TheoryApr 22 2014Jan 17 2015We discuss Liouville field theory in the framework of Schwinger-Dyson approach and derive a functional equation for the three-point structure constant. We argue the existence of a second Schwinger-Dyson equation on the basis of the duality between the ... More
Degree and Sensitivity: tails of two distributionsApr 25 2016The sensitivity of a Boolean function f is the maximum over all inputs x, of the number of sensitive coordinates of x. The well-known sensitivity conjecture of Nisan (see also Nisan and Szegedy) states that every sensitivity-s Boolean function can be ... More
Bounded Independence Fools HalfspacesFeb 21 2009We show that any distribution on {-1,1}^n that is k-wise independent fools any halfspace h with error \eps for k = O(\log^2(1/\eps) /\eps^2). Up to logarithmic factors, our result matches a lower bound by Benjamini, Gurel-Gurevich, and Peled (2007) showing ... More
On the Locality of Codeword SymbolsJun 18 2011Consider a linear [n,k,d]_q code C. We say that that i-th coordinate of C has locality r, if the value at this coordinate can be recovered from accessing some other r coordinates of C. Data storage applications require codes with small redundancy, low ... More
Admissibility of a posterior predictive decision ruleJul 22 2015Jun 25 2016Recent decades have seen an interest in prediction problems for which Bayesian methodology has been extremely useful. Sampling from or approximating the posterior predictive distribution in a Bayesian model allows one to make inferential statements about ... More
Quantifying the information of the prior and likelihood in parametric Bayesian modelingNov 04 2015Jun 25 2016I suggest using a pair of metrics to quantify the information of the prior and likelihood functions within a parametric Bayesian model, one of which is closely related to the reference priors of Berger and Bernardo (Bernardo 1979, Berger and Bernardo ... More
Thompson Sampling for Online Learning with Linear ExpertsNov 03 2013In this note, we present a version of the Thompson sampling algorithm for the problem of online linear generalization with full information (i.e., the experts setting), studied by Kalai and Vempala, 2005. The algorithm uses a Gaussian prior and time-varying ... More
Better Pseudorandom Generators from Milder Pseudorandom RestrictionsSep 28 2012We present an iterative approach to constructing pseudorandom generators, based on the repeated application of mild pseudorandom restrictions. We use this template to construct pseudorandom generators for combinatorial rectangles and read-once CNFs and ... More
Explicit Maximally Recoverable Codes with LocalityJul 16 2013Jul 20 2013Consider a systematic linear code where some (local) parity symbols depend on few prescribed symbols, while other (heavy) parity symbols may depend on all data symbols. Local parities allow to quickly recover any single symbol when it is erased, while ... More
Group Symmetry and Covariance RegularizationNov 30 2011Statistical models that possess symmetry arise in diverse settings such as random fields associated to geophysical phenomena, exchangeable processes in Bayesian statistics, and cyclostationary processes in engineering. We formalize the notion of a symmetric ... More
Piecewise Linearization of Quadratic Branch Flow Limits by Irregular PolygonApr 17 2018Aug 01 2018This letter addresses the issue of linearization of quadratic thermal limits of transmission lines for linear OPF formulation. A new irregular polygon based linearization is proposed. The approach is purely based on geometrical concepts and does not introduce ... More
An Optimal Controller Architecture for Poset-Causal SystemsNov 30 2011We propose a novel and natural architecture for decentralized control that is applicable whenever the underlying system has the structure of a partially ordered set (poset). This controller architecture is based on the concept of Moebius inversion for ... More
Relative Entropy Relaxations for Signomial OptimizationSep 26 2014Signomial programs (SPs) are optimization problems specified in terms of signomials, which are weighted sums of exponentials composed with linear functionals of a decision variable. SPs are non-convex optimization problems in general, and families of ... More
Phase Space Distribution of Riemann ZerosOct 25 2016We present the partition function of a most generic $U(N)$ single plaquette model in terms of representations of unitary group. Extremising the partition function in large N limit we obtain a relation between eigenvalues of unitary matrices and number ... More
Two player game variant of the Erdos-Szekeres problemJul 29 2012The classical Erdos-Szekeres theorem states that a convex $k$-gon exists in every sufficiently large point set. This problem has been well studied and finding tight asymptotic bounds is considered a challenging open problem. Several variants of the Erdos-Szekeres ... More
Conic Geometric ProgrammingOct 03 2013Oct 11 2013We introduce and study conic geometric programs (CGPs), which are convex optimization problems that unify geometric programs (GPs) and conic optimization problems such as semidefinite programs (SDPs). A CGP consists of a linear objective function that ... More
FastGP: An R Package for Gaussian ProcessesJul 22 2015Despite their promise and ubiquity, Gaussian processes (GPs) can be difficult to use in practice due to the computational impediments of fitting and sampling from them. Here we discuss a short R package for efficient multivariate normal functions which ... More
PAC Battling Bandits in the Plackett-Luce ModelAug 12 2018Oct 05 2018We introduce the probably approximately correct (PAC) {Battling-Bandit} problem with the Plackett-Luce (PL) subset choice model---an online learning framework where at each trial the learner chooses a subset of $k$ arms from a fixed set of $n$ arms, and ... More
A Simplified Suspension Calculus and its Relationship to Other Explicit Substitution CalculiFeb 26 2007This paper concerns the explicit treatment of substitutions in the lambda calculus. One of its contributions is the simplification and rationalization of the suspension calculus that embodies such a treatment. The earlier version of this calculus provides ... More
From PAC to Instance-Optimal Sample Complexity in the Plackett-Luce ModelMar 01 2019We consider PAC learning for identifying a good item from subset-wise samples in \pl\, probability models, with instance-dependent sample complexity performance. For the setting where subsets of a fixed size can be tested and top-ranked feedback is made ... More
Smooth Boolean functions are easy: efficient algorithms for low-sensitivity functionsAug 10 2015A natural measure of smoothness of a Boolean function is its sensitivity (the largest number of Hamming neighbors of a point which differ from it in function value). The structure of smooth or equivalently low-sensitivity functions is still a mystery. ... More
Variation of the gas and radiation content in the sub-Keplerian accretion disk around black holes and its impact to the solutionsApr 05 2012We investigate the variation of the gas and the radiation pressure in accretion disks during the infall of matter to the black hole and its effect to the flow. While the flow far away from the black hole might be non-relativistic, in the vicinity of the ... More
Deuteron-like heavy dibaryons from Lattice QCDJun 14 2019We report the first lattice quantum chromodynamics (QCD) study of deuteron($np$)-like dibaryons with heavy quark flavours. These include particles with following dibaryon structures and valence quark contents: $\Sigma_c\Xi_{cc} (uucucc)$, $\Omega_c\Omega_{cc} ... More
Phase Space Distribution for Two-Gap Solution in Unitary Matrix ModelOct 12 2015May 02 2016We analyze the dynamics of weakly coupled finite temperature $U(N)$ gauge theories on $S^3$ by studying a class of effective unitary matrix model. Solving Dyson-Schwinger equation at large $N$, we find that different phases of gauge theories are characterized ... More
Proceedings Sixth International Workshop on Logical Frameworks and Meta-languages: Theory and PracticeOct 31 2011This volume constitutes the proceedings of LFMTP 2011, the Sixth International Workshop on Logical Frameworks and Meta-languages: Theory and Practice. The LFMTP workshop series brings together designers, implementors, and practitioners to discuss varied ... More
A Lambda Prolog Based Animation of Twelf SpecificationsJul 06 2014Specifications in the Twelf system are based on a logic programming interpretation of the Edinburgh Logical Framework or LF. We consider an approach to animating such specifications using a Lambda Prolog implementation. This approach is based on a lossy ... More
Active Ranking with Subset-wise PreferencesOct 23 2018We consider the problem of probably approximately correct (PAC) ranking $n$ items by adaptively eliciting subset-wise preference feedback. At each round, the learner chooses a subset of $k$ items and observes stochastic feedback indicating preference ... More
PAC Battling Bandits in the Plackett-Luce ModelAug 12 2018Mar 01 2019We introduce the probably approximately correct (PAC) \emph{Battling-Bandit} problem with the Plackett-Luce (PL) subset choice model--an online learning framework where at each trial the learner chooses a subset of $k$ arms from a fixed set of $n$ arms, ... More
The Scalar Strange Content of the Nucleon from Lattice QCDJan 07 2013Jun 25 2013The scalar strange-quark matrix element of the nucleon is computed with lattice QCD. A mixed-action scheme is used with domain-wall valence fermions computed on the staggered MILC sea-quark configurations. The matrix element is determined by making use ... More
A Higher-Order Abstract Syntax Approach to Verified Transformations on Functional ProgramsSep 12 2015Jan 23 2016We describe an approach to the verified implementation of transformations on functional programs that exploits the higher-order representation of syntax. In this approach, transformations are specified using the logic of hereditary Harrop formulas. On ... More
Thompson Sampling for Learning Parameterized Markov Decision ProcessesJun 29 2014Mar 31 2015We consider reinforcement learning in parameterized Markov Decision Processes (MDPs), where the parameterization may induce correlation across transition probabilities or rewards. Consequently, observing a particular state transition might yield useful ... More
Regret Minimisation in Multinomial Logit BanditsMar 01 2019We consider two regret minimisation problems over subsets of a finite ground set $[n]$, with subset-wise relative preference information feedback according to the Multinomial logit choice model. The first setting requires the learner to test subsets of ... More
Maximum Inner-Product Search using Tree Data-structuresFeb 28 2012The problem of {\em efficiently} finding the best match for a query in a given set with respect to the Euclidean distance or the cosine similarity has been extensively studied in literature. However, a closely related problem of efficiently finding the ... More
H_2-Optimal Decentralized Control over Posets: A State-Space Solution for State-FeedbackNov 07 2011We develop a complete state-space solution to H_2-optimal decentralized control of poset-causal systems with state-feedback. Our solution is based on the exploitation of a key separability property of the problem, that enables an efficient computation ... More
New Symmetries in Crystals and Handed StructuresJul 21 2010Feb 04 2011For over a century, the structure of materials has been described by a combination of rotations, rotation-inversions and translational symmetries. By recognizing the reversal of static structural rotations between clockwise and counterclockwise directions ... More
The Antisymmetry of DistortionsJun 01 2015Distortions are ubiquitous in nature. Under perturbations such as stresses, fields, or other changes, a physical system reconfigures by following a path from one state to another; this path, often a collection of atomic trajectories, describes a distortion. ... More
Nanoscale piezoelectric response across a single antiparallel ferroelectric domain wallMar 09 2005Surprising asymmetry in the local electromechanical response across a single antiparallel ferroelectric domain wall is reported. Piezoelectric force microscopy is used to investigate both the in-plane and out-of- plane electromechanical signals around ... More
A Topological Approach to Creating any Pulli Kolam, an Artform from Southern IndiaMar 07 2015May 31 2015Pulli kolam is a ubiquitous art form in south India. It involves drawing a line looped around a collection of dots (pullis) place on a plane such that three mandatory rules are followed: all line orbits should be closed, all dots are encircled and no ... More
Limiting Network Size within Finite Bounds for OptimizationMar 07 2019Largest theoretical contribution to Neural Networks comes from VC Dimension which characterizes the sample complexity of classification model in a probabilistic view and are widely used to study the generalization error. So far in the literature the VC ... More
Online Learning in Kernelized Markov Decision ProcessesMay 21 2018Jan 03 2019We consider online learning for minimizing regret in unknown, episodic Markov decision processes (MDPs) with continuous states and actions. We develop variants of the UCRL and posterior sampling algorithms that employ nonparametric Gaussian process priors ... More
Optimal Low-Rank Tensor Recovery from Separable Measurements: Four Contractions SufficeMay 15 2015Tensors play a central role in many modern machine learning and signal processing applications. In such applications, the target tensor is usually of low rank, i.e., can be expressed as a sum of a small number of rank one tensors. This motivates us to ... More
A density matrix approach to the convergence of the self-consistent field iterationSep 06 2018Nov 23 2018In this paper, we present a local convergence analysis of the self-consistent field (SCF) iteration using the density matrix as the state of a fixed-point iteration. Sufficient and almost necessary conditions for local convergence are formulated in terms ... More
The DeWitt Equation in Quantum Field TheoryMar 14 2013We take a new look at the DeWitt equation, a defining equation for the effective action functional in quantum field theory. We present a formal solution to this equation, and discuss the equation in various contexts, and in particular for models where ... More
DNF Sparsification and a Faster Deterministic Counting AlgorithmMay 16 2012Given a DNF formula on n variables, the two natural size measures are the number of terms or size s(f), and the maximum width of a term w(f). It is folklore that short DNF formulas can be made narrow. We prove a converse, showing that narrow formulas ... More
False Discovery and Its Control in Low Rank EstimationOct 19 2018Models specified by low-rank matrices are ubiquitous in contemporary applications. In many of these problem domains, the row/column space structure of a low-rank matrix carries information about some underlying phenomenon, and it is of interest in inferential ... More
A Primal-Dual based Distributed Approximation Algorithm for Prize-Collecting Steiner TreeOct 19 2017Feb 20 2018The Prize-Collecting Steiner Tree (PCST) problem is a generalization of the Steiner Tree problem that has applications in network design, content distribution networks, and many more. There are a few centralized approximation algorithms \cite{DB_MG_DS_DW_1993, ... More
From Phase Space to Integrable Representations and Level-Rank DualityJan 24 2018May 28 2018We explicitly find representations for different large $N$ phases of Chern-Simons matter theory on $S^2\times S^1$. These representations are characterised by Young diagrams. We show that no-gap and lower-gap phase of Chern-Simons-matter theory correspond ... More
On the Exchange Interactions in Holographic p-adic CFTMay 16 2017May 30 2017There is a renewed interest in conformal field theories (CFT) on ultrametric spaces (p-adic field and its algebraic extensions) in view of their natural adaptability in the holographic setting. We compute the contributions from the exchange interactions ... More
Emergent Phase Space Description of Unitary Matrix ModelAug 10 2017Jan 29 2018We show that large $N$ phases of a $0$ dimensional generic unitary matrix model (UMM) can be described in terms of topologies of two dimensional droplets on a plane spanned by eigenvalue and number of boxes in Young diagram. Information about different ... More
Spin-ladders with spin gaps: A description of a class of cupratesDec 06 1993We investigate the magnetic properties of the Cu-O planes in stoichiometric Sr$_{n-1}$Cu$_{n+1}$O$_{2n}$ (n=3,5,7,...) which consist of CuO double chains periodically intergrown within the CuO$_2$ planes. The double chains break up the two-dimensional ... More
A two-level logic approach to reasoning about computationsNov 16 2009Sep 01 2010Relational descriptions have been used in formalizing diverse computational notions, including, for example, operational semantics, typing, and acceptance by non-deterministic machines. We therefore propose a (restricted) logical theory over relations ... More
Online Learning for Structured Loss SpacesJun 13 2017Nov 12 2017We consider prediction with expert advice when the loss vectors are assumed to lie in a set described by the sum of atomic norm balls. We derive a regret bound for a general version of the online mirror descent (OMD) algorithm that uses a combination ... More
Online Ranking with Constraints: A Primal-Dual Algorithm and Applications to Web Traffic-ShapingFeb 22 2017We study the online constrained ranking problem motivated by an application to web-traffic shaping: an online stream of sessions arrive in which, within each session, we are asked to rank items. The challenge involves optimizing the ranking in each session ... More
Visual Monitoring for Multiple Points of Interest on a 2.5D Terrain using a UAV with Limited Field-of-View ConstraintMar 18 2019Varying terrain conditions and limited field-of-view restricts the visibility of aerial robots while performing visual monitoring operations. In this paper, we study the multi-point monitoring problem on a 2.5D terrain using an unmanned aerial vehicle ... More
Collaborative Learning of Stochastic Bandits over a Social NetworkFeb 29 2016Jul 11 2016We consider a collaborative online learning paradigm, wherein a group of agents connected through a social network are engaged in playing a stochastic multi-armed bandit game. Each time an agent takes an action, the corresponding reward is instantaneously ... More
Wireless Scheduling with Partial Channel State Information: Large Deviations and OptimalityMay 24 2014Mar 31 2015We consider a server serving a time-slotted queued system of multiple packet-based flows, with exogenous packet arrivals and time-varying service rates. At each time, the server can observe instantaneous service rates for only a subset of flows (from ... More
Thompson Sampling for Complex Bandit ProblemsNov 03 2013We consider stochastic multi-armed bandit problems with complex actions over a set of basic arms, where the decision maker plays a complex action rather than a basic arm in each round. The reward of the complex action is some function of the basic arms' ... More
Low-rank Bandits with Latent MixturesSep 06 2016We study the task of maximizing rewards from recommending items (actions) to users sequentially interacting with a recommender system. Users are modeled as latent mixtures of C many representative user classes, where each class specifies a mean reward ... More
Combining generic judgments with recursive definitionsFeb 06 2008Apr 14 2008Many semantical aspects of programming languages, such as their operational semantics and their type assignment calculi, are specified by describing appropriate proof systems. Recent research has identified two proof-theoretic features that allow direct, ... More
Misspecified Linear BanditsApr 23 2017We consider the problem of online learning in misspecified linear stochastic multi-armed bandit problems. Regret guarantees for state-of-the-art linear bandit algorithms such as Optimism in the Face of Uncertainty Linear bandit (OFUL) hold under the assumption ... More
Classifying X-ray Binaries: A Probabilistic ApproachJul 13 2015In X-ray binary star systems consisting of a compact object that accretes material from an orbiting secondary star, there is no straightforward means to decide if the compact object is a black hole or a neutron star. To assist this process we develop ... More
Reasoning in Abella about Structural Operational Semantics SpecificationsApr 24 2008Jun 03 2008The approach to reasoning about structural operational semantics style specifications supported by the Abella system is discussed. This approach uses lambda tree syntax to treat object language binding and encodes binding related properties in generic ... More
Scoping Constructs in Logic Programming: Implementation Problems and their SolutionSep 10 1998The inclusion of universal quantification and a form of implication in goals in logic programming is considered. These additions provide a logical basis for scoping but they also raise new implementation problems. When universal and existential quantifiers ... More
Nominal AbstractionAug 10 2009Sep 23 2010Recursive relational specifications are commonly used to describe the computational structure of formal systems. Recent research in proof theory has identified two features that facilitate direct, logic-based reasoning about such descriptions: the interpretation ... More
Linear System Identification via Atomic Norm RegularizationApr 03 2012This paper proposes a new algorithm for linear system identification from noisy measurements. The proposed algorithm balances a data fidelity term with a norm induced by the set of single pole filters. We pose a convex optimization problem that approximately ... More
Matrix Model for Riemann Zeta via its Local FactorsJul 19 2018We propose the construction of an ensemble of unitary random matrices (UMM) for the Riemann zeta function. Our approach to this problem is `piecemeal', in the sense that we consider each factor in the Euler product representation of the zeta function ... More
Plug-and-play dual-tree algorithm runtime analysisJan 21 2015Numerous machine learning algorithms contain pairwise statistical problems at their core---that is, tasks that require computations over all pairs of input points if implemented naively. Often, tree structures are used to solve these problems efficiently. ... More
The $H$ dibaryon from lattice QCD with SU(3) flavor symmetryOct 31 2018We show recent results from the Mainz group using $N_f = 2 + 1$ CLS ensembles generated at the $SU(3)$ symmetric point. Temporal correlation functions using two-baryon interpolating operators are calculated with the distillation method. In addition to ... More
Fault Detection Engine in Intelligent Predictive Analytics Platform for DCIMOct 16 2016With the advancement of huge data generation and data handling capability, Machine Learning and Probabilistic modelling enables an immense opportunity to employ predictive analytics platform in high security critical industries namely data centers, electricity ... More
A Sufficient Condition for Small-Signal Stability and Construction of Robust Stability RegionNov 09 2018The small-signal stability is an integral part of the power system security analysis. The introduction of renewable source related uncertainties is making the stability assessment difficult as the equilibrium point is varying rapidly. This paper focuses ... More
Sketching Sparse MatricesMar 26 2013This paper considers the problem of recovering an unknown sparse p\times p matrix X from an m\times m matrix Y=AXB^T, where A and B are known m \times p matrices with m << p. The main result shows that there exist constructions of the "sketching" matrices ... More
Compressed Sensing off the GridJul 25 2012Jul 10 2013We consider the problem of estimating the frequency components of a mixture of s complex sinusoids from a random subset of n regularly spaced samples. Unlike previous work in compressed sensing, the frequencies are not assumed to lie on a grid, but can ... More
On Application of Learning to Rank for E-Commerce SearchMar 01 2019E-Commerce (E-Com) search is an emerging important new application of information retrieval. Learning to Rank (LETOR) is a general effective strategy for optimizing search engines, and is thus also a key technology for E-Com search. While the use of LETOR ... More
Cooperative Planning for Fuel-constrained Aerial Vehicles and Ground-based Refueling Vehicles for Large-Scale CoverageMay 11 2018Low cost Unmanned Aerial Vehicles (UAVs) need multiple refuels to accomplish large area coverage. The number of refueling stations and their placement plays a vital role in determining coverage efficiency. In this paper, we propose the use of a ground-based ... More
Optimal WiFi Sensing via Dynamic ProgrammingOct 28 2014The problem of finding an optimal sensing schedule for a mobile device that encounters an intermittent WiFi access opportunity is considered. At any given time, the WiFi is in any of the two modes, ON or OFF, and the mobile's incentive is to connect to ... More
The Bedwyr system for model checking over syntactic expressionsFeb 20 2007Apr 25 2008Bedwyr is a generalization of logic programming that allows model checking directly on syntactic expressions possibly containing bindings. This system, written in OCaml, is a direct implementation of two recent advances in the theory of proof search. ... More
Tables of crystallographic properties of double antisymmetry space groupsNov 29 2013Tables of crystallographic properties of double antisymmetry space groups, including symmetry element diagrams, general position diagrams, and positions, with multiplicities, site symmetries, coordinates, spin and roto vectors are presented.
DiSPy: Implementation of Distortion Symmetry for the Nudged Elastic Band MethodOct 03 2018Dec 20 2018The nudged elastic band (NEB) method is a commonly used approach for the calculation of minimum energy pathways of kinetic processes. However, the final paths obtained rely heavily on the nature of the initially chosen path. This often necessitates running ... More
Fast Exact Max-Kernel SearchOct 23 2012Oct 26 2012The wide applicability of kernels makes the problem of max-kernel search ubiquitous and more general than the usual similarity search in metric spaces. We focus on solving this problem efficiently. We begin by characterizing the inherent hardness of the ... More
Learning to Multi-Task by Active SamplingFeb 20 2017May 21 2017One of the long-standing challenges in Artificial Intelligence for learning goal-directed behavior is to build a single agent which can solve multiple tasks. Recent progress in multi-task learning for goal-directed sequential problems has been in the ... More
Morphology of Open Clusters NGC 1857 and Czernik 20 using Clustering AlgorithmsNov 01 2016The morphology and cluster membership of the Galactic open clusters - Czernik 20 and NGC 1857 were analyzed using two different clustering algorithms. We present the maiden use of density-based spatial clustering of applications with noise (DBSCAN) to ... More
Reasoning About Higher-Order Relational SpecificationsFeb 11 2013Aug 05 2013The logic of hereditary Harrop formulas (HH) has proven useful for specifying a wide range of formal systems. This logic includes a form of hypothetical judgment that leads to dynamically changing sets of assumptions and that is key to encoding side conditions ... More
Weighted bandits or: How bandits learn distorted values that are not expectedNov 30 2016Motivated by models of human decision making proposed to explain commonly observed deviations from conventional expected value preferences, we formulate two stochastic multi-armed bandit problems with distorted probabilities on the cost distributions: ... More
Epidemic Spreading with External AgentsJun 15 2012Apr 13 2014We study epidemic spreading processes in large networks, when the spread is assisted by a small number of external agents: infection sources with bounded spreading power, but whose movement is unrestricted vis-\`a-vis the underlying network topology. ... More
Double Antisymmetry and the Rotation-Reversal Space GroupsMar 08 2013Rotation-reversal symmetry was recently introduced to generalize the symmetry classification of rigid static rotations in crystals such as tilted octahedra in perovskite structures and tilted tetrahedral in silica structures. This operation has important ... More