Results for "Amartya Sanyal"

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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
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
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
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
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
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
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
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
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
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
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
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
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
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 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
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
Symmetry-adapted real-space density functional theory for cylindrical geometries: application to large X (X=C, Si, Ge, Sn) nanotubesApr 30 2019We present a symmetry-adapted real-space formulation of Kohn-Sham density functional theory for cylindrical geometries and apply it to the study of large X (X=C, Si, Ge, Sn) nanotubes. Specifically, starting from the Kohn-Sham equations posed on all of ... More
Local-Access Generators for Basic Random Graph ModelsNov 29 2017Consider a computation on a massive random graph: Does one need to generate the whole random graph up front, prior to performing the computation? Or, is it possible to provide an oracle to answer queries to the random graph "on-the-fly" in a much more ... 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
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
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
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
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))
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
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
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
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
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
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
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
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.
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.
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
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
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
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
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
A spectral scheme for Kohn-Sham density functional theory of clustersApr 14 2014Nov 25 2014Starting from the observation that one of the most successful methods for solving the Kohn-Sham equations for periodic systems -- the plane-wave method -- is a spectral method based on eigenfunction expansion, we formulate a spectral method designed towards ... 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
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
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
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
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
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
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
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
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
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
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
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
Heuristic Algorithm using Internet of Things and Mobility for solving demographic issues in Financial Inclusion projectsMar 01 2015All over the world, the population in rural and semi-urban areas is a major concern for policy makers as they require technology enablement most to get elevated from their living conditions. Financial Inclusion projects are meant to work in this area ... 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
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
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
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
Application Layer Intrusion Detection with Combination of Explicit-Rule- Based and Machine Learning Algorithms and Deployment in Cyber- Defence ProgramNov 12 2014There have been numerous works on network intrusion detection and prevention systems, but work on application layer intrusion detection and prevention is rare and not very mature. Intrusion detection and prevention at both network and application layers ... More
Theta rank, levelness, and matroid minorsAug 06 2014Nov 03 2016The 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
Ehrhart theory, Modular flow reciprocity, and the Tutte polynomialJul 05 2009Given an oriented graph G, the modular flow polynomial counts the number of nowhere-zero Z_k-flows of G. We give a description of the modular flow polynomial in terms of (open) Ehrhart polynomials of lattice polytopes. Using Ehrhart-Macdonald reciprocity ... More
Irrational behavior of algebraic discrete valuationsNov 23 2013Jun 10 2014We study algebraic discrete valuations dominating normal local domains of dimension two. We construct a family of examples to show that the Hilbert-Samuel function of the associated graded ring of the valuation can fail to be asymptotically of the form: ... More
Laplacian ideals, arrangements, and resolutionsDec 26 2012Aug 22 2016The Laplacian matrix of a graph G describes the combinatorial dynamics of the Abelian Sandpile Model and the more general Riemann-Roch theory of G. The lattice ideal associated to the lattice generated by the columns of the Laplacian provides an algebraic ... More
Combinatorial positivity of translation-invariant valuations and a discrete Hadwiger theoremMay 27 2015Jul 17 2018We 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
Periodic Pulay method for robust and efficient convergence acceleration of self-consistent field iterationsDec 05 2015Jan 13 2016Pulay's Direct Inversion in the Iterative Subspace (DIIS) method is one of the most widely used mixing schemes for accelerating the self-consistent solution of electronic structure problems. In this work, we propose a simple generalization of DIIS in ... More
A Novel Multipath Approach to Security in Mobile Ad Hoc Networks (MANETs)Nov 23 2011In this paper, we present a novel encryption-less algorithm to enhance security in transmission of data packets across mobile ad hoc networks. The paper hinges on the paradigm of multipath routing and exploits the properties of polynomials. The first ... More
Cloud Computing -- An Approach with Modern CryptographyMar 05 2013In this paper we are proposing an algorithm which uses AES technique of 128/192/256 bit cipher key in encryption and decryption of data. AES provides high security as compared to other encryption techniques along with RSA. Cloud computing provides the ... More
Security Architecture for Cluster based Ad Hoc NetworksJul 06 2012Mobile Ad hoc Networks (MANETs) are subject to various kinds of attacks. Deploying security mechanisms is difficult due to inherent properties of ad hoc networks, such as the high dynamics of their topology, restricted bandwidth, and limited resources ... More
Routing Protocols for Mobile and Vehicular Ad-Hoc Networks: A Comparative AnalysisJun 09 2012We present comparative analysis of MANET (Mobile Ad-Hoc Network) and VANET (Vehicular Ad-Hoc Network) routing protocols, in this paper. The analysis is based on various design factors. The traditional routing protocols of AODV (Ad hoc On-Demand Distance ... More
A Heuristic Reputation Based System to Detect Spam activities in a Social Networking Platform, HRSSSNPDec 09 2012The introduction of the social networking platform has drastically affected the way individuals interact. Even though most of the effects have been positive, there exist some serious threats associated with the interactions on a social networking website. ... More
A Multi-Dimensional approach towards Intrusion Detection SystemMay 10 2012In this paper, we suggest a multi-dimensional approach towards intrusion detection. Network and system usage parameters like source and destination IP addresses; source and destination ports; incoming and outgoing network traffic data rate and number ... More
Thermodynamics of irreversible particle creation phenomena and its cosmological consequenceAug 16 2017The study of particle creation phenomena at the expense of the gravitational field is of great research interest. It might solve the cosmological puzzle single-handedly, without the need for either dark energy or the modified theory of gravity. In the ... More
On the equivalence between different canonical forms of F(R) theory of gravityAug 05 2017Classical equivalence between Jordan's and Einstein's frame counterparts of F(R) theory of gravity has recently been questioned, since the two produce different Noether symmetries, which couldn't be translated back and forth using transformation relations. ... More
Revisiting Noether gauge symmetry for F(R) theory of gravityAug 11 2012Noether gauge symmetry for F(R) theory of gravity has been explored recently. The fallacy is that, even after setting gauge to vanish, the form of F(R) \propto R^n (where n \neq 1, is arbitrary) obtained in the process, has been claimed to be an outcome ... More
Equivalent and inequivalent canonical structures of higher order theories of gravitySep 15 2017Aug 15 2018Canonical formulation of higher order theory of gravity can only be accomplished associating additional degrees of freedom, which are extrinsic curvature tensor. Consequently, to match Cauchy data with the boundary data, terms in addition to the three-space ... More
Revisiting Noether symmetry approach in F(R)-tachyon ModelAug 17 2012Nov 12 2013Recently, some authors have made a falsifiable claim that Noether gauge symmetry for F(R) theory of gravity coupled to a tachyon field enforces gauge to vanish and leads to F(R) \propto R^2, with a tachyon potential V(\phi) \propto \phi^{-4}. Here, we ... More
Is Noether Symmetric Approach Consistent With Dynamical Equation In Non-minimal Scalar-Tensor Theories?Jul 14 2001The form of the coupling of the scalar field with gravity and the potential have been found by applying Noether theorem to two dimensional minisuperspaces in induced gravity model. It has been observed that though the forms thus obtained are consistent ... More