Results for "Amartya Sanyal"

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Optimizing Non-decomposable Measures with Deep NetworksJan 31 2018We present a class of algorithms capable of directly training deep neural networks with respect to large families of task-specific performance measures such as the F-measure and the Kullback-Leibler divergence that are structured and non-decomposable. ... More
Learning Low-Rank RepresentationsApr 19 2018Mar 21 2019A key feature of neural networks, particularly deep convolutional neural networks, is their ability to "learn" useful representations from data. The very last layer of a neural network is then simply a linear model trained on these "learned" representations. ... More
Agent based simulation of the evolution of society as an alternate maximization problemJul 05 2017Understanding the evolution of human society, as a complex adaptive system, is a task that has been looked upon from various angles. In this paper, we simulate an agent-based model with a high enough population tractably. To do this, we characterize an ... More
Oscillators with Parametrically Excited Nonlinearity: Resonance, Anti-resonance and SwitchFeb 29 2012We discover presence of a hitherto unexplored type of resonance in a parametrically excited Van der Pol oscillator. The oscillator also possesses a state of anti-resonance. In the weak non-linear limit, we explain how to practically get a complete picture ... More
Multiscale sequence modeling with a learned dictionaryJul 03 2017Jul 05 2017We propose a generalization of neural network sequence models. Instead of predicting one symbol at a time, our multi-scale model makes predictions over multiple, potentially overlapping multi-symbol tokens. A variation of the byte-pair encoding (BPE) ... More
Stable Rank Normalization for Improved Generalization in Neural Networks and GANsJun 11 2019Jun 12 2019Exciting new work on the generalization bounds for neural networks (NN) given by Neyshabur et al. , Bartlett et al. closely depend on two parameter-depenedent quantities: the Lipschitz constant upper-bound and the stable rank (a softer version of the ... More
TAPAS: Tricks to Accelerate (encrypted) Prediction As a ServiceJun 09 2018Machine learning methods are widely used for a variety of prediction problems. \emph{Prediction as a service} is a paradigm in which service providers with technological expertise and computational resources may perform predictions for clients. However, ... More
Stable Rank Normalization for Improved Generalization in Neural Networks and GANsJun 11 2019Exciting new work on the generalization bounds for neural networks (NN) given by Neyshabur et al. , Bartlett et al. depend on two parameter-depenedent quantities: the Lipschitz constant upper-bound and the stable rank (a softer version of the rank operator). ... More
Fluctuations and magnetoresistance oscillations near the half-filled Landau levelJan 23 2019We study magnetoresistance oscillations near the half-filled lowest Landau level ($\nu = 1/2$) that result from the presence of a periodic one-dimensional electrostatic potential using the Dirac composite fermion theory of Son, where the $\nu=1/2$ state ... More
Duality in non-abelian algebra IV. Duality for groups and a universal isomorphism theoremApr 06 2017Dec 02 2018Abelian categories provide a self-dual axiomatic context for establishing homomorphism theorems (such as the isomorphism theorems and homological diagram lemmas) for abelian groups, and more generally, modules. In this paper we describe a self-dual context ... More
Power-law Distributions in the Kauffman NetOct 27 1995Kauffman net is a dynamical system of logical variables receiving two random inputs and each randomly assigned a boolean function. We show that the attractor and transient lengths exhibit scaleless behavior with power-law distributions over up to ten ... More
Cyclic Density Functional Theory : A route to the first principles simulation of bending in nanostructuresMay 28 2016Sep 01 2016We formulate and implement Cyclic Density Functional Theory (Cyclic DFT) -- a self-consistent first principles simulation method for nanostructures with cyclic symmetries. Using arguments based on Group Representation Theory, we rigorously demonstrate ... More
Renormalization group and isochronous oscillationsOct 17 2011We show how the condition of isochronicity can be studied for two dimensional systems in the renormalization group (RG) context. We find a necessary condition for the isochronicity of the Cherkas and another class of cubic systems. Our conditions are ... More
BMS Characters and Modular InvarianceFeb 19 2019Jul 25 2019We construct the characters for the highest weight representations of the 3d Bondi-Metzner-Sachs (BMS$_3$) algebra. We then use these to construct the partition function and show how to use BMS modular transformations to obtain a density of primary states. ... More
On Residual and Stable CoordinatesAug 09 2019In a recent paper, M. E. Kahoui and M. Ouali have proved that over an algebraically closed field $k$ of characteristic zero, residual coordinates in $k[X][Z_1,\dots,Z_n]$ are one-stable coordinates. In this paper we extend their result to the case of ... More
Persistence Exponent for Diffusion: The Exact SolutionMay 02 2010The persistence exponent for diffusion equation with random gaussian initial conditions has been calculated for any dimension $d$. The value of the exponent in the asymptotic limit for large time comes out to be $d/4$ . The result is at variance with ... More
Limits on the Charged Higgs Parameters in the Two Higgs Doublet Model using CMS $\sqrt{s}=13$ TeV ResultsJun 06 2019Latest CMS results on the upper limits on $\sigma_{H^\pm}$BR($H^\pm \rightarrow \tau\nu)$ and $\sigma_{H^\pm}$BR($H^+ \rightarrow t\bar{b}$) for $\sqrt{s}=13$ TeV at an integrated luminosity of 35.9 fb$^{-1}$ are used to impose constraints on the charged ... More
Topological obstructions for vertex numbers of Minkowski sumsFeb 23 2007Mar 22 2007We show that for polytopes P_1, P_2, ..., P_r \subset \R^d, each having n_i \ge d+1 vertices, the Minkowski sum P_1 + P_2 + ... + P_r cannot achieve the maximum of \prod_i n_i vertices if r \ge d. This complements a recent result of Fukuda & Weibel (2006), ... More
A Composition Theorem via Conflict ComplexityJan 10 2018Let $\R(\cdot)$ stand for the bounded-error randomized query complexity. We show that for any relation $f \subseteq \{0,1\}^n \times \mathcal{S}$ and partial Boolean function $g \subseteq \{0,1\}^n \times \{0,1\}$, $\R_{1/3}(f \circ g^n) = \Omega(\R_{4/9}(f) ... More
Neutrino inflation of baryon inhomogeneities in strong magnetic fieldsMar 01 2004Baryon inhomogeneitites formed in the early universe are important as they affect the nucleosynthesis calculations. Since they are formed much before the nucleosynthesis epoch, neutrino inflation plays a crucial role in damping out these fluctuations. ... More
Effect of citation patterns on network structureNov 15 2006We propose a model for an evolving citation network that incorporates the citation pattern followed in a particular discipline. We define the citation pattern in a discipline by three factors. The average number of references per article, the probability ... More
On the derivative cones of polyhedral conesMay 15 2011Nov 10 2011Hyperbolic polynomials elegantly encode a rich class of convex cones that includes polyhedral and spectrahedral cones. Hyperbolic polynomials are closed under taking polars and the corresponding cones, the derivative cones, yield relaxations for the associated ... More
Antiferromagnetic metal phases in double perovskites having strong antisite defect concentrationsFeb 18 2015Recently an antiferromagnetic metal phase has been proposed in double perovskites materials like Sr$_{2}$FeMoO$_{6}$ (SFMO), when electron doped. This material has been found to change from half-metallic ferromagnet to antiferromagnetic metal (AFM) upon ... More
Energy Harvesting in M2M and WSN SpaceJan 19 2014Energy harvesting or power harvesting or energy scavenging is a process where energy is derived from external sources (e.g. solar power, thermal energy, wind energy, salinity gradients, kinetic energy etc.), captured, and stored for small, wireless autonomous ... More
Limits on the Charged Higgs Parameters in the Two Higgs Doublet Model using CMS $\sqrt{s}=13$ TeV ResultsJun 06 2019Jun 17 2019Latest CMS results on the upper limits on $\sigma_{H^\pm}$BR($H^\pm \rightarrow \tau^\pm\nu)$ and $\sigma_{H^\pm}$BR($H^+ \rightarrow t\bar{b}$) for $\sqrt{s}=13$ TeV at an integrated luminosity of 35.9 fb$^{-1}$ are used to impose constraints on the ... More
Data Aggregation Techniques for Internet of ThingsJul 24 2019The goal of this dissertation is to design efficient data aggregation frameworks for massive IoT networks in different scenarios to support the proper functioning of IoT analytics layer. This dissertation includes modern algorithmic frameworks such as ... More
Understanding ferromagnetism in Cr-based 3d-5d double perovskitesFeb 26 2012Sep 20 2012Ferromagnetism in Cr-based double perovskites is analyzed using effective model as well as simulation approach. Starting from a microscopic model proposed recently for this class of double perovskites, an effective spin-only model is derived in the limit ... More
Phase Transition between 'A' and 'B' forms of DNA: A Free Energy PerspectiveMar 16 2010Apr 04 2010We study the structural transition from `B' form of DNA to 'A' form of DNA using group theoretic methods. The transition is not of the order-disorder type and hence to construct a Landau kind of theory for the transition we define a higher symmetry and ... More
On codimension-one $\mathbb A^1$-fibration with retractionFeb 21 2013In this paper we prove some results on the sufficiency of codimension-one fibre conditions for a flat algebra with a retraction to be locally $\mathbb{A}^1$ or at least an $\mathbb{A}^1$-fibration.
Cyclic Density Functional Theory : A route to the first principles simulation of bending in nanostructuresMay 28 2016Mar 15 2017We formulate and implement Cyclic Density Functional Theory (Cyclic DFT) -- a self-consistent first principles simulation method for nanostructures with cyclic symmetries. Using arguments based on Group Representation Theory, we rigorously demonstrate ... More
Sub-linear Upper Bounds on Fourier dimension of Boolean Functions in terms of Fourier sparsityJul 13 2014We prove that the Fourier dimension of any Boolean function with Fourier sparsity $s$ is at most $O\left(s^{2/3}\right)$. Our proof method yields an improved bound of $\widetilde{O}(\sqrt{s})$ assuming a conjecture of Tsang~\etal~\cite{tsang}, that for ... More
Effect of pre-existing baryon inhomogeneities on the dynamics of quark-hadron transitionNov 13 2002Mar 06 2003Baryon number inhomogeneities may be generated during the epoch when the baryon asymmetry of the universe is produced, e.g. at the electroweak phase transition. The regions with excess baryon number will have a lower temperature than the background temperature ... More
A Note on Separable $\A^2$ and $\A^3$-formsFeb 11 2018In this note, we shall prove that any $\A^3$-form over a field $k$ of characteristic zero is trivial provided it has a locally nilpotent derivation satisfying certain properties. We shall also show that the result of T. Kambayashi on the triviality of ... More
On Separable $\A^2$ and $\A^3$-formsFeb 11 2018Mar 06 2019In this paper, we will prove that any $\A^3$-form over a field $k$ of characteristic zero is trivial provided it has a locally nilpotent derivation satisfying certain properties. We will also show that the result of T. Kambayashi on the triviality of ... More
On two-dimensionalization of three-dimensional turbulence in shell modelsMar 15 2008Feb 03 2010Applying a modified version of the Gledzer-Ohkitani-Yamada (GOY) shell model, the signatures of so-called two-dimensionalization effect of three-dimensional incompressible, homogeneous, isotropic fully developed unforced turbulence have been studied and ... More
Quantum Mechanical Probability Interpretation In The Mini-superspace Model Of Higher Order Gravity TheoryMay 14 2002It has been shown that inclusion of higher order curvature invariant terms in the Robertson-Walker minisuperspace model of the Einstein-Hilbert action leads to Schrodinger like equation, whose corresponding effective action is hermitian. Thus, it is possible ... More
Partition function of massless scalar field in Schwarzschild backgroundSep 26 2014Using thermal value of zeta function instead of zero temperature, the partition function of quantized fields in arbitrary stationary backgrounds was found to be independent of undetermined regularization constant in even-dimension and the long drawn problem ... More
Flow and vorticity with varying chemical potential in relativistic heavy ion collisionsFeb 22 2019We study the vorticity patterns in relativistic heavy ion collisions with respect to the collision energy. The collision energy is related to the chemical potential used in the thermal - statistical models that assume approximate chemical equilibrium ... More
Primordial magnetic field generation in the Quark Gluon Plasma phaseNov 29 2017Dec 17 2018In this work we investigate the possibility of generation of primordial magnetic field in the early universe near the QCD phase transition epoch via the collapse of $Z(3)$ domains. The $Z(3)$ domain walls arise in the deconfined phase of the QCD (above ... More
The zero-error randomized query complexity of the pointer functionJul 06 2016The pointer function of G{\"{o}}{\"{o}}s, Pitassi and Watson \cite{DBLP:journals/eccc/GoosP015a} and its variants have recently been used to prove separation results among various measures of complexity such as deterministic, randomized and quantum query ... More
Technical Analysis of Security Infrastructure in RFID TechnologyMay 01 2015The paper is a technical analysis of the security infrastructure in the field of RFID technology. The paper briefly discusses the architecture of the RFID technology. Then it analyses the various features and advantages RFID technology has over the existing ... More
Survey on Security Issues in Cloud Computing and Associated Mitigation TechniquesApr 03 2012May 21 2012Cloud Computing holds the potential to eliminate the requirements for setting up of high-cost computing infrastructure for IT-based solutions and services that the industry uses. It promises to provide a flexible IT architecture, accessible through internet ... More
Lepton specific two Higgs doublet model based on $U(1)_X$ gauge symmetry with dark matterJul 05 2019We discuss a two Higgs doublet model with extra $U(1)_X$ gauge symmetry where lepton specific (type-X) structure for Yukawa interactions is realized by charge assignment of fields under the $U(1)_X$. Extra charged leptons are introduced to cancel gauge ... More
Neutrino currents in wakes of cosmic stringsJun 24 2019Neutrinos rotating around Abelian Higgs strings will generate a neutral current close to the string. As the string moves through the cosmic plasma, the velocity kick generated by the motion of the string will enhance the neutrino current in the wake region. ... More
Multi-hypothesis classifierAug 20 2019Accuracy is the most important parameter among few others which defines the effectiveness of a machine learning algorithm. Higher accuracy is always desirable. Now, there is a vast number of well established learning algorithms already present in the ... More
A Magnetic Model for the Ordered Double PerovskitesDec 05 2008We construct an effective spin model from the coupled spin-fermion problem appropriate to double perovskites of the form A_2BB'O_6. The magnetic model that emerges is reminiscent of double exchange and we illustrate this `reduction' in detail for the ... More
Structural and magnetic properties of Fe/ZnSe(001) interfacesMar 28 2002We have performed first principles electronic structure calculations to investigate the structural and magnetic properties of Fe/ZnSe(001) interfaces. Calculations involving full geometry optimizations have been carried out for a broad range of thickness ... More
Minkowski complexes and convex threshold dimensionJul 26 2016For a collection of convex bodies $P_1,\dots,P_n \subset \mathbb{R}^d$ containing the origin, a Minkowski complex is given by those subsets whose Minkowski sum does not contain a fixed basepoint. Every simplicial complex can be realized as a Minkowski ... More
Combinatorial mixed valuationsMay 24 2016We introduce combinatorial mixed valuations associated to translation-invariant valuations on polytopes. In contrast to the construction of mixed valuations via polarization, combinatorial mixed valuations reflect and often inherit properties of inhomogeneous ... More
Degenerate Hamiltonian - the problem and a remedyJul 08 2018Aug 13 2018Different routes towards canonical formulation of a specic non-minimally coupled higher-order theory of gravity, result in at least two different Hamiltonian, which are not related under canonical transformation. Both the Hamiltonian yield correct classical ... More
Enlightening the dark universeDec 20 2016Lot of avenues, the black hole, the wormhole, the dark matter, the dark energy etc. have been opened since the advent of General Theory of Relativity in 1915. Cosmology, the physics of creation and evolution of the universe, which was once thought to ... More
An Energy-Efficient VCO-Based Matrix Multiplier Block to Support On-Chip Image AnalysisDec 11 2016Images typically are represented as uniformly sampled data in the form of matrix of pixels/voxels. Therefore, matrix multiply-and-accumulate (MAC) forms the core of most state-of-the-art image analysis algorithms. While digital implementation of MAC has ... More
Digital Watermarking Techniques in Spatial and Frequency DomainJun 09 2014Oct 13 2014Digital watermarking is the act of hiding information in multimedia data, for the purposes of content protection or authentication. In ordinary digital watermarking, the secret information is embedded into the multimedia data (cover data) with minimum ... More
Reversible and Irreversible Data Hiding TechniqueMay 12 2014May 20 2014Steganography (literally meaning covered writing) is the art and science of embedding secret message into seemingly harmless message. Stenography is practice from olden days where in ancient Greece people used wooden blocks to inscribe secret data and ... More
A translation: "Every" finite free resolution is a free resolution of an ideal generated by three elementsDec 27 2010A translation into English of Winfried Bruns' article: "Jede" endliche freie Aufl\"osung ist freie Aufl\"osung eines von drei Elementen erzeugten Ideals' (published in J. Algebra 39, 429-439 (1976))
Non-projectability of polytope skeletaAug 06 2009We investigate necessary conditions for the existence of projections of polytopes that preserve full k-skeleta. More precisely, given the combinatorics of a polytope and the dimension e of the target space, what are obstructions to the existence of a ... More
Baryon inhomogeneities in a charged quark gluon plasmaSep 05 2013We study the generation of baryon inhomogeneities in regions of the quark gluon plasma which have a charge imbalance. We find that the overdensity in the baryon lumps for positively charged particles is different from the overdensity due to the negatively ... More
Optimal Attitude Estimation and Filtering Without Using Local Coordinates Part I: Uncontrolled and Deterministic Attitude DynamicsSep 15 2005There are several attitude estimation algorithms in existence, all of which use local coordinate representations for the group of rigid body orientations. All local coordinate representations of the group of orientations have associated problems. While ... More
Survey of Strong Authentication Approaches for Mobile Proximity and Remote Wallet Applications - Challenges and EvolutionDec 09 2014Wallet may be described as container application used for configuring, accessing and analysing data from underlying payment application(s). There are two dominant types of digital wallet applications, proximity wallet and remote wallet. In the payment ... More
Quantum Weak TurbulenceFeb 15 2004The study of the phenomenon of quantum weak turbulence is extended by determining the quasiparticle spectrum associated with such a system using a Green's function approach. The quasiparticle spectrum calculated establishes the dissipative regime and ... More
Theta rank, levelness, and matroid minorsAug 06 2014Sep 08 2015The Theta rank of a finite point configuration $V$ is the maximal degree necessary for a sum-of-squares representation of a non-negative linear function on $V$. This is an important invariant for polynomial optimization that is in general hard to determine. ... More
Magnetism and magnetic asphericity in NiFe alloysMar 23 1999We here study magnetic properties of Ni$_{x}$Fe$_{1-x}$ using Augmented space recursion technique coupled with tight-binding linearized muffin tin orbital method. Also the spectral properties of this alloy has been studied here.
Scalar tensor theory of gravity carrying a conserved currentApr 04 2005A general scalar-tensor theory of gravity carries a conserved current for a trace free minimally coupled scalar field, under the condition that the potential $V(\phi)$ of the nonminimally coupled scalar field is proportional to the square of the parameter ... More
Noether and some other dynamical symmetries in Kantowski-Sachs modelJul 16 2001The forms of coupling of the scalar field with gravity, appearing in the induced theory of gravity, and the potential are found in the Kantowski-Sachs model under the assumption that the Lagrangian admits Noether symmetry. The form thus obtained makes ... More
Nonlinearly Stable Real-Time Learning and Model-Free ControlJul 25 2019This work provides a framework for nonlinear model-free control of systems with unknown input-output dynamics, but outputs that can be controlled by the inputs. This framework leads to real-time control of the system such that a feasible output trajectory ... More
Primordial Magnetic Field Via Weibel Instability In The Quark Gluon Plasma PhaseMar 09 2016Sep 09 2016The origin of the observed large scale magnetic fields in the Universe is a mystery. The seed of these magnetic fields has been attributed to physical process in the early universe. In this work we provide a mechanism for the generation of a primordial ... More
Rule Based Expert System for Diagnosis of Neuromuscular DisordersJul 09 2012In this paper, we discuss the implementation of a rule based expert system for diagnosing neuromuscular diseases. The proposed system is implemented as a rule based expert system in JESS for the diagnosis of Cerebral Palsy, Multiple Sclerosis, Muscular ... More
Rule Based Expert System for Cerebral Palsy DiagnosisJun 30 2012The use of Artificial Intelligence is finding prominence not only in core computer areas, but also in cross disciplinary areas including medical diagnosis. In this paper, we present a rule based Expert System used in diagnosis of Cerebral Palsy. The expert ... More
Shortened Hamming Codes Maximizing Double Error DetectionNov 08 2010May 21 2011Given $r\geq 3$ and $2^{r-1}+1\leq n< 2^{r}-1$, an $[n,n-r,3]$ shortened Hamming code that can detect a maximal number of double errors is constructed. The optimality of the construction is proven.
Collusion resistant self-healing key distribution in mobile wireless networksJun 26 2012A fundamental concern of any secure group communication system is key management and wireless environments create new challenges. One core requirement in these emerging networks is self-healing. In systems where users can be offline and miss updates, ... More
An Alexander-type duality for valuationsMar 07 2013We prove an Alexander-type duality for valuations for certain subcomplexes in the boundary of polyhedra. These strengthen and simplify results of Stanley (1974) and Miller-Reiner (2005). We give a generalization of Brion's theorem for this relative situation ... More
Minkowski complexes and convex threshold dimensionJul 26 2016Mar 10 2017For a collection of convex bodies $P_1,\dots,P_n \subset \mathbb{R}^d$ containing the origin, a Minkowski complex is given by those subsets whose Minkowski sum does not contain a fixed basepoint. Every simplicial complex can be realized as a Minkowski ... More
Relative Stanley-Reisner theory and Upper Bound Theorems for Minkowski sumsMay 28 2014Mar 07 2016In this paper we settle long-standing questions regarding the combinatorial complexity of Minkowski sums of polytopes: We give a tight upper bound for the number of faces of a Minkowski sum, including a characterization of the case of equality. We similarly ... More
Review of Considerations for Mobile Device based Secure Access to Financial Services and Risk Handling Strategy for CIOs, CISOs and CTOsFeb 03 2015The information technology and security stakeholders like CIOs, CISOs and CTOs in financial services organization are often asked to identify the risks with mobile computing channel for financial services that they support. They are also asked to come ... More
Analysis of Applicability of ISO 9564 PIN based Authentication to Closed-Loop Mobile Payment SystemsNov 11 2014Payment transactions initiated through a mobile device are growing and security concerns must be ad-dressed. People coming from payment card industry often talk passionately about porting ISO 9564 PIN standard based authentication in open-loop card payment ... More
On degree sequences of undirected, directed, and bidirected graphsDec 28 2015Bidirected graphs generalize directed and undirected graphs in that edges are oriented locally at every node. The natural notion of the degree of a node that takes into account (local) orientations is that of net-degree. In this paper, we extend the following ... More
Smooth crossing of $w_Λ = -1$ line in a single scalar field modelOct 18 2007Dec 18 2007Smooth double crossing of the phantom divide line $w_{\Lambda}=-1$ has been found possible with a single minimally coupled scalar field for the most simple form of generalized k-essence cosmological model, in the presence of background cold dark matter. ... More
Intermediate inflation or late time acceleration?Apr 26 2007Sep 28 2007The expansion rate of `Intermediate inflation' lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of `Intermediate inflation' reveals that it ... More
If Gauss-Bonnet interaction plays the role of dark energyAug 04 2006Aug 14 2006Gauss-Bonnet-scalar interaction has been found to play a crucial role from the beginning till the late time of cosmological evolution. A cosmological model has been constructed where the Universe starts with exponential expansion but with infinite deceleration ... More
Study of symmetry in F(R) theory of gravityOct 13 2009An action in which the Ricci scalar is nonminimally coupled with a scalar field and contains higher order curvature invariant terms carries a conserved current under certain conditions that decouples geometric part from the scalar field. The conserved ... More
Quantum cosmology of a classically constrained nonsingular UniverseOct 13 2009The quantum cosmological version of a nonsingular Universe presented by Mukhanov and Brandenberger in the early nineties has been developed and the Hamilton Jacobi equation has been found under semiclassical (WKB) approximation. It has been pointed out ... More
Quantum Mechanical Formulation Of Quantum Cosmology For Brane-World Effective ActionMay 12 2003Canonical quantization of the Brane-World effective action presented by Kanno and Soda containing higher order curvature invariant terms, has been performed. It requires introduction of an auxiliary variable. As observed in a series of publications by ... More
Increasing Security in Cloud EnvironmentJan 02 2013The concept of cloud computing was introduced to meet the increase in demand for new application for a project, and to provide a large storage facility whenever or wherever a user needs it. The cloud system facility helped many industries as well as individual ... More
A Review of Techniques to Mitigate Sybil AttacksJul 11 2012Any decentralised distributed network is particularly vulnerable to the Sybil attack wherein a malicious node masquerades as several different nodes, called Sybil nodes, simultaneously in an attempt to disrupt the proper functioning of the network. Such ... More
A Survey on Various Data Hiding Techniques and their Comparative AnalysisJun 09 2012With the explosive growth of internet and the fast communication techniques in recent years the security and the confidentiality of the sensitive data has become of prime and supreme importance and concern. To protect this data from unauthorized access ... More
Machine Translation Systems in IndiaApr 29 2013Machine Translation is the translation of one natural language into another using automated and computerized means. For a multilingual country like India, with the huge amount of information exchanged between various regions and in different languages ... More
Lepton specific two Higgs doublet model based on $U(1)_X$ gauge symmetry with dark matterJul 05 2019Jul 14 2019We discuss a two Higgs doublet model with extra $U(1)_X$ gauge symmetry where lepton specific (type-X) structure for Yukawa interactions is realized by charge assignment of fields under the $U(1)_X$. Extra charged leptons are introduced to cancel gauge ... More
Towards Better Separation between Deterministic and Randomized Query ComplexityJun 21 2015Jun 24 2015We show that there exists a Boolean function $F$ which observes the following separations among deterministic query complexity $(D(F))$, randomized zero error query complexity $(R_0(F))$ and randomized one-sided error query complexity $(R_1(F))$: $R_1(F) ... More
Diffusion of massive particles around an Abelian-Higgs stringOct 16 2017Mar 09 2018We study the diffusion of massive particles in the space time of an Abelian Higgs string. The particles in the early universe plasma execute Brownian motion. This motion of the particles is modeled as a two dimensional random walk in the plane of the ... More
Combinatorial mixed valuationsMay 24 2016Aug 21 2017Combinatorial mixed valuations associated to translation-invariant valuations on polytopes are introduced. In contrast to the construction of mixed valuations via polarization, combinatorial mixed valuations reflect and often inherit properties of inhomogeneous ... More
Applicability of DUKPT Key Management Scheme to Cloud Wallet and other Mobile PaymentsDec 08 2014After discussing the concept of DUKPT based symmetric encryption key management (e.g., for 3DES) and definition of cloud or remote wallet, the paper analyses applicability of DUKPT to different use cases like mobile banking, NFC payment using EMV contactless ... More
Lipschitz polytopes of posets and permutation statisticsMar 30 2017We introduce Lipschitz functions on a finite partially ordered set $P$ and study the associated Lipschitz polytope $L(P)$. The geometry of $L(P)$ can be described in terms of descent-compatible permutations and permutation statistics that generalize descents ... More
On degree sequences of undirected, directed, and bidirected graphsDec 28 2015Apr 10 2017Bidirected graphs generalize directed and undirected graphs in that edges are oriented locally at every node. The natural notion of the degree of a node that takes into account (local) orientations is that of net-degree. In this paper, we extend the following ... More
Arithmetic of marked order polytopes, monotone triangle reciprocity, and partial coloringsJun 18 2012Jul 18 2014For a poset P, a subposet A, and an order preserving map F from A into the real numbers, the marked order polytope parametrizes the order preserving extensions of F to P. We show that the function counting integral-valued extensions is a piecewise polynomial ... More
Crystal growth of the non-magnetic Zn$^{2+}$ and magnetic Co$^{2+}$ doped quasi one-dimensional spin chain compound SrCuO$_{2}$ using the travelling solvent floating zone methodJan 10 2015We report on the crystal growth of the quasi one-dimensional quantum spin chain compound SrCuO$_{2}$ and its doped variants containing magnetic cobalt (0.25%, 0.5%, 1% and 2.5%) and non-magnetic zinc (0.5\% and 1\%) impurities. Crystals are grown using ... More
Combinatorial positivity of translation-invariant valuations and a discrete Hadwiger theoremMay 27 2015Oct 15 2015We introduce the notion of combinatorial positivity of translation-invariant valuations on convex polytopes that extends the nonnegativity of Ehrhart h*-vectors. We give a surprisingly simple characterization of combinatorially positive valuations that ... More
Smooth Hyperbolicity Cones are Spectrahedral ShadowsAug 02 2012Hyperbolicity cones are convex algebraic cones arising from hyperbolic polynomials. A well-understood subclass of hyperbolicity cones is that of spectrahedral cones and it is conjectured that every hyperbolicity cone is spectrahedral. In this paper we ... More
Prover and Verifier Based Password Protection: PVBPPDec 25 2012In today's world password are mostly used for authentication. This makes them prone to various kinds of attacks like dictionary attacks. A dictionary attack is a method of breaking the password by systematically entering every word in a dictionary as ... More
Steganalysis: Detecting LSB Steganographic TechniquesMay 20 2014Steganalysis means analysis of stego images. Like cryptanalysis, steganalysis is used to detect messages often encrypted using secret key from stego images produced by steganography techniques. Recently lots of new and improved steganography techniques ... More
Flow and vorticity with varying chemical potential in relativistic heavy ion collisionsFeb 22 2019Jul 03 2019We study the vorticity patterns in relativistic heavy ion collisions with respect to the collision energy. The collision energy is related to the chemical potential used in the thermal - statistical models that assume approximate chemical equilibrium ... More