Results for "V. Nagarajan"

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The magnetoresistance in GdNi: Magnetic-polaronic-like effect near Curie temperature and low temperature sign reversalDec 04 1998The results of magnetoresistance ($\Delta \rho /\rho$)measurements in GdNi, in the temperature range 4.2 to 300 K are reported. The sign of $\Delta \rho /\rho $ above the Curie temperature (Tc= 70 K) is negative and its magnitude in a magnetic field of ... More
Magnetic Properties of Ternary Gallides of type RNi4Ga (R = Rare earths)Nov 14 2005The magnetic properties of RNi4Ga (R = La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm and Lu) compounds have been investigated. These compounds form in a hexagonal CaCu5 type structure with a space group P6/mmm. Compounds with the magnetic rare earths, R = Nd, ... More
Magnetization and heat capacity studies of double perovskite compounds Ba2SmRuO6 and Ba2DyRuO6Jul 07 2007Here we report the magnetic and heat capacity studies of the double perovskite com-pounds Ba2SmRuO6 and Ba2DyRuO6. Antiferromagnetic transitions are inferred at 54 K and 47 K in Ba2SmRuO6 and Ba2DyRuO6, respectively in the magnetization measure-ments. ... More
Switching behaviour of stilbene molecular device: a first-principles studyDec 20 2018The switching behaviour of stilbene molecular system (SMS) device is investigated with the help of non-equilibrium Green's function (NEGF) approach using first principles calculation. The transmission spectrum of cis-isomers confirmed that more electrons ... More
Anomalous magnetic and transport properties of La(0.8-x)Eu(x)Sr0.2MnO3 (0.04 l.e. x l.e. 0.36) compoundsApr 02 2008Anomalous magnetic and transport properties observed in the La0.8-xEuxSr0.2MnO3 (0.04 l.e x l.e. 0.36) compounds are presented in this paper. The Curie temperature (TC) decreases from 260 K for x = 0.04 to 188 K for x = 0.16 and surprisingly thereafter ... More
Nitrogen dioxide and ammonia gas molecules interaction studies on phosphorene nanosheet --- a DFT investigationMar 27 2019The adsorption behaviour of hazardous gas molecules, namely nitrogen dioxide (NO$_2$) and ammonia (NH$_3$), on phosphorene nanosheet (PNS) was explored by means of ab initio technique. To improve the structural solidity of pristine PNS, we have introduced ... More
Analysis of Birth weight using Singular Value DecompositionFeb 10 2010The researchers have drawn much attention about the birth weight of newborn babies in the last three decades. The birth weight is one of the vital roles in the babys health. So many researchers such as (2),(1) and (4) analyzed the birth weight of babies. ... More
Sensing behavior of acetone vapors on TiO$_2$ nanostructures --- application of density functional theoryDec 14 2017The electronic properties of TiO$_2$ nanostructure are explored using density functional theory. The adsorption properties of acetone on TiO$_2$ nanostructure are studied in terms of adsorption energy, average energy gap variation and Mulliken charge ... More
Thrifty Algorithms for Multistage Robust OptimizationFeb 21 2013We consider a class of multi-stage robust covering problems, where additional information is revealed about the problem instance in each stage, but the cost of taking actions increases. The dilemma for the decision-maker is whether to wait for additional ... More
Is non-Gaussianity sufficient to produce long-range volatile correlations?Oct 19 2005Jan 27 2006Scaling analysis of the magnitude series (volatile series) has been proposed recently to identify possible nonlinear/multifractal signatures in the given data [1-3]. In this letter, correlations of volatile series generated from stationary first-order ... More
Delay estimation in a two-node acyclic networkApr 24 2007Linear measures such as cross-correlation have been used successfully to determine time delays from the given processes. Such an analysis often precedes identifying possible causal relationships between the observed processes. The present study investigates ... More
Extrapolating Beyond Suboptimal Demonstrations via Inverse Reinforcement Learning from ObservationsApr 12 2019A critical flaw of existing inverse reinforcement learning (IRL) methods is their inability to significantly outperform the demonstrator. This is a consequence of the general reliance of IRL algorithms upon some form of mimicry, such as feature-count ... More
Comment of Global dynamics of biological systemsJun 20 2008In a recent study, (Grigorov, 2006) analyzed temporal gene expression profiles (Arbeitman et al., 2002) generated in a Drosophila experiment using SSA in conjunction with Monte-Carlo SSA. The author (Grigorov, 2006) makes three important claims in his ... More
Interpreting non-random signatures in biomedical signals with Lempel-Ziv complexityAug 20 2006Sep 07 2007Lempel-Ziv complexity (LZ) [1] and its variants have been used widely to identify non-random patterns in biomedical signals obtained across distinct physiological states. Non-random signatures of the complexity measure can occur under nonlinear deterministic ... More
Power-law Signatures and Patchiness in Genechip Oligonucleotide MicroarraysSep 07 2007Oct 31 2007. Genechip oligonucleotide microarrays have been used widely for transcriptional profiling of a large number of genes in a given paradigm. Gene expression estimation precedes biological inference and is given as a complex combination of atomic entities ... More
Surrogate testing of volatility series from long-range correlated noiseMar 15 2006Jun 13 2006Detrended fluctuation analysis (DFA) [1] of the volatility series has been found to be useful in dentifying possible nonlinear/multifractal dynamics in the empirical sample [2-4]. Long-range volatile correlation can be an outcome of static as well as ... More
Effect of coarse-graining on detrended fluctuation analysisOct 17 2005Several studies have investigated the scaling behavior in naturally occurring biological and physical processes using techniques such as detrended fluctuation analysis (DFA). Data acquisition is an inherent part of these studies and maps the continuous ... More
Local Analysis of Dissipative Dynamical SystemsOct 23 2005Linear transformation techniques such as singular value decomposition (SVD) have been used widely to gain insight into the qualitative dynamics of data generated by dynamical systems. There have been several reports in the past that had pointed out the ... More
Reliable scaling exponent estimation of long-range correlated noise in the presence of random spikesOct 19 2005Detrended fluctuation analysis (DFA) has been used widely to determine possible long-range correlations in data obtained from diverse settings. In a recent study [1], uncorrelated random spikes superimposed on the long-range correlated noise (LR noise) ... More
Surrogate testing of linear feedback processes with non-Gaussian innovationsOct 19 2005Mar 16 2006Surrogate testing is used widely to determine the nature of the process generating the given empirical sample. In the present study, the usefulness of phase-randomized surrogates, amplitude adjusted Fourier transform (AAFT) and iterated amplitude adjusted ... More
Magnetic and Transport Properties of Ternary Indides of type R2CoIn8 (R = Ce, Pr and Dy)Jan 24 2005We have synthesized and investigated the magnetic and transport properties of a series of compounds, R2CoIn8 (R = rare earth). Compounds form in single phase with a tetragonal structure (space group P4/mmm, no. 162). The Ce compound shows heavy fermion ... More
Probing La(0.7)Sr(0.3)MnO3 multilayers via spin wave resonancesDec 20 2010La(0.7)Sr(0.3)MnO3/BiFeO3 and La(0.7)Sr(0.3)MnO3/PbZr20Ti80O3 epitaxial heterostructures have been grown on SrTiO3 substrates. Spin wave resonances are used to study interface properties of the ferromagnetic La(0.7)Sr(0.3)MnO3. We find that the addition ... More
Information retrieval from a phoneme time series databaseDec 27 2007Developing fast and efficient algorithms for retrieval of objects to a given user query is an area of active research. The present study investigates retrieval of time series objects from a phoneme database to a given user pattern or query. The proposed ... More
On Identifying Significant Edges in Graphical Models of Molecular NetworksApr 05 2011Apr 23 2013Objective: Modelling the associations from high-throughput experimental molecular data has provided unprecedented insights into biological pathways and signalling mechanisms. Graphical models and networks have especially proven to be useful abstractions ... More
Communicating Quantum ProcessesSep 09 2004We define a language CQP (Communicating Quantum Processes) for modelling systems which combine quantum and classical communication and computation. CQP combines the communication primitives of the pi-calculus with primitives for measurement and transformation ... More
Regret Bounds for Non-decomposable Metrics with Missing LabelsJun 07 2016We consider the problem of recommending relevant labels (items) for a given data point (user). In particular, we are interested in the practically important setting where the evaluation is with respect to non-decomposable (over labels) performance metrics ... More
A Novel Control-flow based Intrusion Detection Technique for Big Data SystemsNov 23 2016Security and distributed infrastructure are two of the most common requirements for big data software. But the security features of the big data platforms are still premature. It is critical to identify, modify, test and execute some of the existing security ... More
A System Architecture for the Detection of Insider Attacks in Big Data SystemsDec 05 2016In big data systems, the infrastructure is such that large amounts of data are hosted away from the users. In such a system information security is considered as a major challenge. From a customer perspective, one of the big risks in adopting big data ... More
Quasi-Polynomial Algorithms for Submodular Tree Orienteering and Other Directed Network Design ProblemsDec 05 2018Apr 01 2019We consider the following general network design problem on directed graphs. The input is an asymmetric metric $(V,c)$, root $r^{*}\in V$, monotone submodular function $f:2^V\rightarrow \mathbb{R}_+$ and budget $B$. The goal is to find an $r^{*}$-rooted ... More
A Stochastic Probing Problem with ApplicationsFeb 24 2013We study a general stochastic probing problem defined on a universe V, where each element e in V is "active" independently with probability p_e. Elements have weights {w_e} and the goal is to maximize the weight of a chosen subset S of active elements. ... More
Magnetoresistance in ordered and disordered double perovskite oxide, Sr$_2$FeMoO$_6$Mar 14 2000We have prepared crystallographically ordered and disorder specimens of the double perovskite, Sr$_2$FeMoO$_6$ and investigated their magnetoresistance behaviour. The extent of ordering between the Fe and Mo sites in the two samples is determined by Rietveld ... More
Approximation-Friendly Discrepancy RoundingDec 07 2015Rounding linear programs using techniques from discrepancy is a recent approach that has been very successful in certain settings. However this method also has some limitations when compared to approaches such as randomized and iterative rounding. We ... More
On the Adaptivity Gap of Stochastic OrienteeringNov 14 2013May 09 2014The input to the stochastic orienteering problem consists of a budget $B$ and metric $(V,d)$ where each vertex $v$ has a job with deterministic reward and random processing time (drawn from a known distribution). The processing times are independent across ... More
Approximation-Friendly Discrepancy RoundingDec 07 2015Dec 02 2016Rounding linear programs using techniques from discrepancy is a recent approach that has been very successful in certain settings. However this method also has some limitations when compared to approaches such as randomized and iterative rounding. We ... More
Lossless Quantum CompressionAug 23 2005Mar 21 2006We describe lossless quantum compression of unknown mixtures (of non-orthogonal states) and give an expression of the optimal rate of compression.
Correlation Statistics for cDNA Microarray Image AnalysisNov 16 2005In this report, correlation of the pixels comprising a microarray spot is investigated. Subsequently, correlation statistics namely: Pearson correlation and Spearman rank correlation are used to segment the foreground and background intensity of microarray ... More
On Feedback and the Classical Capacity of a Noisy Quantum ChannelMay 29 2003In Shannon information theory the capacity of a memoryless communication channel cannot be increased by the use of feedback from receiver to sender. In this paper the use of classical feedback is shown to provide no increase in the unassisted classical ... More
Formal Verification of Quantum ProtocolsMar 18 2002We propose to analyse quantum protocols by applying formal verification techniques developed in classical computing for the analysis of communicating concurrent systems. One area of successful application of these techniques is that of classical security ... More
Approximating Sparse Covering Integer Programs OnlineMay 01 2012A covering integer program (CIP) is a mathematical program of the form: min {c^T x : Ax >= 1, 0 <= x <= u, x integer}, where A is an m x n matrix, and c and u are n-dimensional vectors, all having non-negative entries. In the online setting, the constraints ... More
Reversible Logic Based Concurrent Error Detection Methodology For Emerging NanocircuitsJan 21 2011Reversible logic has promising applications in emerging nanotechnologies, such as quantum computing, quantum dot cellular automata and optical computing, etc. Faults in reversible logic circuits that result in multi-bit error at the outputs are very tough ... More
Qualitative Assessment of Gene Expression in Affymetrix Genechip ArraysApr 12 2006May 19 2006Affymetrix Genechip microarrays are used widely to determine the simultaneous expression of genes in a given biological paradigm. Probes on the Genechip array are atomic entities which by definition are randomly distributed across the array and in turn ... More
Impact of Tandem Repeats on the Scaling of Nucleotide SequencesOct 21 2005Techniques such as detrended fluctuation analysis (DFA) and its extensions have been widely used to determine the nature of scaling in nucleotide sequences. In this brief communication we show that tandem repeats which are ubiquitous in nucleotide sequences ... More
Approximation Algorithms for Inventory Problems with Submodular or Routing CostsApr 24 2015We consider the following two deterministic inventory optimization problems over a finite planning horizon $T$ with non-stationary demands. (a) Submodular Joint Replenishment Problem: This involves multiple item types and a single retailer who faces demands. ... More
Some Tractable Win-Lose GamesOct 28 2010Oct 29 2010Determining a Nash equilibrium in a $2$-player non-zero sum game is known to be PPAD-hard (Chen and Deng (2006), Chen, Deng and Teng (2009)). The problem, even when restricted to win-lose bimatrix games, remains PPAD-hard (Abbott, Kane and Valiant (2005)). ... More
A Qualitative Description of Boundary Layer Wind Speed RecordsApr 04 2006The complexity of the atmosphere endows it with the property of turbulence by virtue of which, wind speed variations in the atmospheric boundary layer (ABL) exhibit highly irregular fluctuations that persist over a wide range of temporal and spatial scales. ... More
Minimizing the effect of sinusoidal trends in detrended fluctuation analysisNov 21 2004The detrended fluctuation analysis (DFA) [Peng et al., 1994] and its extensions (MF-DFA) [Kantelhardt et al., 2002] have been used extensively to determine possible long-range correlations in self-affine signals. While the DFA has been claimed to be a ... More
Complex phase mixture and domain superstructure across a new lead-free ferroelectric/anti-ferroelectric morphotropic phase boundaryMar 06 2008May 23 2008We investigate the microstructural evolution in a ferroelectric to antiferroelectric phase transition at the morphotropic phase boundary in the Bi(1-x)SmxFeO3 system. Continuous Sm3+ substitution on the A-site induces short-range anti-parallel cation ... More
Coexistence of orbital and quantum critical magnetoresistance in FeSe$_{1-x}$S$_{x}$Mar 13 2019The recent discovery of a non-magnetic nematic quantum critical point (QCP) in the iron chalcogenide family FeSe$_{1-x}$S$_{x}$ has raised the prospect of investigating, in isolation, the role of nematicity on the electronic properties of correlated metals. ... More
Combinatorial discovery of a lead-free morphotropic phase boundary in a thin-film piezoelectric perovskiteMar 01 2008We report on the discovery of a lead-free morphotropic phase boundary in Sm doped BiFeO3 with a simple perovskite structure using the combinatorial thin film strategy. The boundary is a rhombohedral to pseudo-orthorhombic structural transition which exhibits ... More
Minimizing the effect of trends on detrended fluctuation analysis of long-range correlated noiseDec 29 2004Detrended fluctuation analysis (DFA) has been proposed as a robust technique to determine possible long-range correlations in power-law processes [1]. However, recent studies have reported the susceptibility of DFA to trends [2] which give rise to spurious ... More
Appropriateness of correlated first order auto-regressive processes for modeling daily temperature recordsDec 24 2005The present study investigates linear and volatile (nonlinear) correlations of first-order autoregressive process with uncorrelated AR (1) and long-range correlated CAR (1) Gaussian innovations as a function of the process parameter ($\theta$). In the ... More
A Multifractal Description of Wind Speed RecordsNov 20 2004In this paper, a systematic analysis of hourly wind speed data obtained from four potential wind generation sites in North Dakota is conducted. The power spectra of the data exhibited a power law decay characteristic of $1/f^{\alpha}$ processes with possible ... More
Enforcing the non-negativity constraint and maximum principles for diffusion with decay on general computational gridsMar 27 2010Jun 05 2010In this paper, we consider anisotropic diffusion with decay, and the diffusivity coefficient to be a second-order symmetric and positive definite tensor. It is well-known that this particular equation is a second-order elliptic equation, and satisfies ... More
On the Convergence of EM for truncated mixtures of two GaussiansFeb 19 2019Motivated by a recent result of Daskalakis et al. \cite{DGTZ18}, we analyze the population version of Expectation-Maximization (EM) algorithm for the case of \textit{truncated} mixtures of two Gaussians. Truncated samples from a $d$-dimensional mixture ... More
Uniform convergence may be unable to explain generalization in deep learningFeb 13 2019We cast doubt on the power of uniform convergence-based generalization bounds to provide a complete picture of why overparameterized deep networks generalize well. While it is well-known that many existing bounds are numerically large, through a variety ... More
Distributed Anomaly Detection using Autoencoder Neural Networks in WSN for IoTDec 12 2018Wireless sensor networks (WSN) are fundamental to the Internet of Things (IoT) by bridging the gap between the physical and the cyber worlds. Anomaly detection is a critical task in this context as it is responsible for identifying various events of interests ... More
Evidence of crossover phenomena in wind speed dataNov 20 2004In this report, a systematic analysis of hourly wind speed data obtained from three potential wind generation sites (in North Dakota) is analyzed. The power spectra of the data exhibited a power-law decay characteristic of $1/f^{\alpha}$ processes with ... More
Locating Depots for Capacitated Vehicle RoutingMar 04 2011We study a location-routing problem in the context of capacitated vehicle routing. The input is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute ... More
On the Convergence of EM for truncated mixtures of two GaussiansFeb 19 2019Mar 16 2019Motivated by a recent result of Daskalakis et al. \cite{DGTZ18}, we analyze the population version of Expectation-Maximization (EM) algorithm for the case of \textit{truncated} mixtures of two Gaussians. Truncated samples from a $d$-dimensional mixture ... More
Percolative nature of the dc paraconductivity in the cuprate superconductorsOct 27 2017We present an investigation of the planar direct-current (dc) paraconductivity of the model cuprate material HgBa$_2$CuO$_{4+\delta}$ in the underdoped part of the phase diagram. The simple quadratic temperature-dependence of the Fermi-liquid normal-state ... More
Tuning of the superconducting and ferromagnetic transitions by Cu doping for Ru in GdSr2RuCu2O8Mar 15 2003In order to explore the possibility of tuning superconducting and ferromagnetic transitions by Cu doping (for Ru) in GdSr2RuCu2O8, we have carried out synthesis and characterization of GdSr2Ru{1-x}Cu{2+x)O8 (x = 0, 0.05, 0.1, 0.2) and studied their physical ... More
Synchronization in Electrically Coupled Neural NetworksMar 29 2006In this report, we investigate the synchronization of temporal activity in an electrically coupled neural network model. The electrical coupling is established by homotypic static gap-junctions (Connexin 43). Two distinct network topologies, namely: {\em ... More
Model for Predicting End User Web Page Response TimeApr 27 2012Perceived responsiveness of a web page is one of the most important and least understood metrics of web page design, and is critical for attracting and maintaining a large audience. Web pages can be designed to meet performance SLAs early in the product ... More
Strain-induced magnetic phase transition in SrCoO$_{3-δ}$ thin filmsFeb 18 2015It has been well established that both in bulk at ambient pressure and for films under modest strains, cubic SrCoO$_{3-\delta}$ ($\delta < 0.2$) is a ferromagnetic metal. Recent theoretical work, however, indicates that a magnetic phase transition to ... More
Phase Coexistence Near a Morphotropic Phase Boundary in Sm-doped BiFeO3 FilmsMar 11 2010Jun 15 2010We have investigated heteroepitaxial films of Sm-doped BiFeO3 with a Sm-concentration near a morphotropic phase boundary. Our high-resolution synchrotron X-ray diffraction, carried out in a temperature range of 25C to 700C, reveals substantial phase coexistence ... More
Defect thermodynamics and kinetics in thin strained ferroelectric films: the interplay of possible mechanismsNov 13 2013We present a theoretical description of the influence of misfit strain on mobile defects dynamics in thin strained ferroelectric films. Self-consistent solutions obtained by coupling the Poissons equation for electric potential with continuity equations ... More
Call Trace and Memory Access Pattern based Runtime Insider Threat Detection for Big Data PlatformsNov 22 2016Big data platforms such as Hadoop and Spark are being widely adopted both by academia and industry. In this paper, we propose a runtime intrusion detection technique that understands and works according to the properties of such distributed compute platforms. ... More
Approximation Algorithms for the A Priori TravelingRepairmanJan 19 2019We consider the a priori traveling repairman problem, which is a stochastic version of the classic traveling repairman problem (also called the traveling deliveryman or minimum latency problem). Given a metric $(V,d)$ with a root $r\in V$, the traveling ... More
Electrowetting on dielectrics on lubricating fluid based slippery surfaces with negligible hysteresisJul 09 2015Low voltage electrowetting on dielectrics on substrates with thin layer of lubricating fluid to reduce contact angle hysteresis is reported here. On smooth and homogeneous solid surfaces, it is extremely difficult to reduce contact angle hysteresis (contact ... More
QMC: A Model Checker for Quantum SystemsApr 27 2007Apr 21 2008We introduce a model-checking tool intended specially for the analysis of quantum information protocols. The tool incorporates an efficient representation of a certain class of quantum circuits, namely those expressible in the so-called stabiliser formalism. ... More
A numerical methodology for enforcing maximum principles and the non-negative constraint for transient diffusion equationsJun 04 2012Aug 02 2013Transient diffusion equations arise in many branches of engineering and applied sciences (e.g., heat transfer and mass transfer), and are parabolic partial differential equations. It is well-known that, under certain assumptions on the input data, these ... More
Minimum Makespan Multi-vehicle Dial-a-RideFeb 26 2011Dial a ride problems consist of a metric space (denoting travel time between vertices) and a set of m objects represented as source-destination pairs, where each object requires to be moved from its source to destination vertex. We consider the multi-vehicle ... More
Stability, Efficiency, and Contentedness of Social Storage NetworksMar 24 2016Apr 10 2018Social storage systems are a good alternative to existing data backup systems of local, centralized, and P2P backup. In this paper, we look at two untouched aspects of social storage systems. One aspect involves modelling social storage as an endogenous ... More
Grounded Human-Object Interaction Hotspots from VideoDec 11 2018Apr 02 2019Learning how to interact with objects is an important step towards embodied visual intelligence, but existing techniques suffer from heavy supervision or sensing requirements. We propose an approach to learn human-object interaction "hotspots" directly ... More
Stock Market Trend Analysis Using Hidden Markov ModelsNov 19 2013Price movements of stock market are not totally random. In fact, what drives the financial market and what pattern financial time series follows have long been the interest that attracts economists, mathematicians and most recently computer scientists ... More
Max-Cut under Graph ConstraintsNov 25 2015An instance of the graph-constrained max-cut (GCMC) problem consists of (i) an undirected graph G and (ii) edge-weights on a complete undirected graph on the same vertex set. The objective is to find a subset of vertices satisfying some graph-based constraint ... More
Particle size effects in the antiferromagnetic spinel CoRh$_2$O$_4$Oct 30 2002We report the particle size dependent magnetic behaviour in the antiferromagnetic spinel CoRh2O4. The nanoparticles were obtained by mechanical milling of bulk material, prepared under sintering method. The XRD spectra show that the samples are retaining ... More
Thresholded Covering Algorithms for Robust and Max-Min OptimizationDec 05 2009Feb 24 2011The general problem of robust optimization is this: one of several possible scenarios will appear tomorrow, but things are more expensive tomorrow than they are today. What should you anticipatorily buy today, so that the worst-case cost (summed over ... More
Grounded Human-Object Interaction Hotspots from VideoDec 11 2018Learning how to interact with objects is an important step towards embodied visual intelligence, but existing techniques suffer from heavy supervision or sensing requirements. We propose an approach to learn human-object interaction "hotspots" directly ... More
Microwave Properties of Borocarbide Superconductors LnNi2B2C (Ln = Y, Er, Tm, Ho)Apr 21 1995Apr 21 1995We report measurements of the microwave surface impedance of the borocarbide family of superconductors LnNi2B2C (Ln=Y, Er, Tm, Ho). The experiments enable direct measurements of the superfluid density, and are particularly sensitive to the influence of ... More
Static magnetic response of clusters in Co_{0.2}Zn_{0.8}Fe_{1.95}Ho_{0.05}O_{4} spinel oxideJun 25 2003Earlier investigation of Co_{0.2}Zn_{0.8}Fe_{1.95}Ho_{0.05}O_{4} spinel has shown the existence of "super-ferromagnetic " clusters containing Fe^{3+} and Ho^{3+} ions along with small size clusters of Fe^{3+} ions (Bhowmik et al, J. Magn. Magn. Mater. ... More
Robust and MaxMin Optimization under Matroid and Knapsack Uncertainty SetsDec 22 2010Feb 24 2011Consider the following problem: given a set system (U,I) and an edge-weighted graph G = (U, E) on the same universe U, find the set A in I such that the Steiner tree cost with terminals A is as large as possible: "which set in I is the most difficult ... More
Probabilistic Model--Checking of Quantum ProtocolsApr 01 2005Oct 05 2005We establish fundamental and general techniques for formal verification of quantum protocols. Quantum protocols are novel communication schemes involving the use of quantum-mechanical phenomena for representation, storage and transmission of data. As ... More
Formalization of Quantum Protocols using CoqNov 05 2015Quantum Information Processing, which is an exciting area of research at the intersection of physics and computer science, has great potential for influencing the future development of information processing systems. The building of practical, general ... More
A New Approach to Dimensionality Reduction for Anomaly Detection in Data TrafficJun 14 2016The monitoring and management of high-volume feature-rich traffic in large networks offers significant challenges in storage, transmission and computational costs. The predominant approach to reducing these costs is based on performing a linear mapping ... More
Externalities in Socially-Based Resource Sharing NetworkNov 25 2018This paper investigates the impact of link formation between a pair of agents on resource availability of other agents in a social cloud network, which is a special case of socially-based resource sharing systems. Specifically, we study the correlation ... More
Stochastic Vehicle Routing with RecourseFeb 26 2012Mar 01 2012We study the classic Vehicle Routing Problem in the setting of stochastic optimization with recourse. StochVRP is a two-stage optimization problem, where demand is satisfied using two routes: fixed and recourse. The fixed route is computed using only ... More
Element-Specific Depth Profile of Magnetism and Stoichiometry at the La0.67Sr0.33MnO3/BiFeO3 InterfaceJul 02 2014Depth-sensitive magnetic, structural and chemical characterization is important in the understanding and optimization of novel physical phenomena emerging at interfaces of transition metal oxide heterostructures. In a simultaneous approach we have used ... More
Adaptivity Gaps for Stochastic Probing: Submodular and XOS FunctionsAug 02 2016Suppose we are given a submodular function $f$ over a set of elements, and we want to maximize its value subject to certain constraints. Good approximation algorithms are known for such problems under both monotone and non-monotone submodular functions. ... More
Adaptive Submodular RankingJun 05 2016We study a general adaptive ranking problem where an algorithm needs to perform a sequence of actions on a random user, drawn from a known distribution, so as to "satisfy" the user as early as possible. The satisfaction of each user is captured by an ... More
Unique Stability Point in Social Storage NetworksMar 24 2016Sep 14 2016We model social storage systems as a strategic network formation game. We define the utility of each player in the network under two different frameworks, one where the cost to add and maintain links is considered in the utility function and the other ... More
Lattice expansion and non-collinear to collinear ferrimagnetic order in MnCr$_2$O$_4$ nanoparticleOct 30 2005We report magnetic behaviour of MnCr$_2$O$_4$, which belongs to a special class of spinel, known as chromite. Bulk MnCr$_2$O$_4$ shows a sequence of magnetic states, which follows paramagnetic (PM) to collinear ferrimagnetic (FM) state below T$_C$ $\sim$ ... More
Approximation Algorithms for Stochastic k-TSPOct 04 2016We consider the stochastic $k$-TSP problem where rewards at vertices are random and the objective is to minimize the expected length of a tour that collects reward $k$. We present an adaptive $O(\log k)$-approximation algorithm, and a non-adaptive $O(\log^2k)$-approximation ... More
Second Quantized Kolmogorov ComplexitySep 16 2008The Kolmogorov complexity of a string is the length of its shortest description. We define a second quantised Kolmogorov complexity where the length of a description is defined to be the average length of its superposition. We discuss this complexity's ... More
Lossless Quantum Prefix Compression for Communication Channels that are Always OpenAug 14 2008Jan 19 2009We describe a method for lossless quantum compression if the output of the information source is not known. We compute the best possible compression rate, minimizing the expected base length of the output quantum bit string (the base length of a quantum ... More
Ferroelectric NanotubesMar 28 2003We report the independent invention of ferroelectric nanotubes from groups in several countries. Devices have been made with three different materials: lead zirconate-titanate PbZr1-xTixO3 (PZT); barium titanate BaTiO3; and strontium bismuth tantalate ... More
Effect of large neutron excess on the dipole response in the region of the Giant Dipole ResonanceJul 17 1997The evolution of the Dipole Response in nuclei with strong neutron excess is studied in the Hartree-Fock plus Random Phase Approximation with Skyrme forces. We find that the neutron excess increases the fragmentation of the isovector Giant Dipole Resonance, ... More
Effectiveness of sparse Bayesian algorithm for MVAR coefficient estimation in MEG/EEG source-space causality analysisNov 14 2012This paper examines the effectiveness of a sparse Bayesian algorithm to estimate multivariate autoregressive coefficients when a large amount of background interference exists. This paper employs computer experiments to compare two methods in the source-space ... More
Extrapolating Beyond Suboptimal Demonstrations via Inverse Reinforcement Learning from ObservationsApr 12 2019May 14 2019A critical flaw of existing inverse reinforcement learning (IRL) methods is their inability to significantly outperform the demonstrator. This is because IRL typically seeks a reward function that makes the demonstrator appear near-optimal, rather than ... More
Automated Verification of Quantum Protocols by Equivalence CheckingDec 20 2013In this paper we introduce a technique and a tool for formal verification of various quantum information processing protocols. The tool uses stabilizer formalism and is capable of representing concurrent quantum protocol, thus is more expressive than ... More