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Some Studies On Selected Stream Ciphers Analysis Fault Attack & Related Results., Subhadeep Banik Dr.
Some Studies On Selected Stream Ciphers Analysis Fault Attack & Related Results., Subhadeep Banik Dr.
Doctoral Theses
Stream Ciphers are important Symmetric Cryptological primitives, built for the purpose of providing secure message encryption. As no formal security proofs exist, our confidence in these algorithms is largely based on the fact that intense cryptanalysis has been carried out over several years without revealing any weakness. This thesis makes some independent contributions to the cryptanalysis of a selection of stream ciphers.In this thesis, we take a closer look at two stream ciphers viz. RC4+ designed by Maitra et al. at Indocrypt 2008 and GGHN designed by Gong et al. at CISC 2005. Both these ciphers were designed as viable …
Generic Constructions Of Different Cryptographic Primitives Over Various Public Key Paradigms., Sumit Kumar Pandey Dr.
Generic Constructions Of Different Cryptographic Primitives Over Various Public Key Paradigms., Sumit Kumar Pandey Dr.
Doctoral Theses
In this thesis, we study the generic construction of some cryptographic primitives over various public key paradigms like traditional Public Key Cryptosystems and Identity Based Cryptosystems. It can be broadly divided into two categories1. Generic construction of some highly secure cryptographic primitives from less secure cryptographic primitives, and2. Generic construction of some complex cryptographic primitives from basic cryptographic primitives. Mathematical tools provide a way to achieve cryptographic functionality like confidentiality, authentication, data-integrity, non-repudiation etc., but in the case of complex cryptographic functionality like achieving confidentiality and authentication at the same time or confidentiality, authentication and non-repudiation at the same time …
Some Conjugacy Problems In Algebraic Groups., Anirban Bose Dr.
Some Conjugacy Problems In Algebraic Groups., Anirban Bose Dr.
Doctoral Theses
In this thesis we address two problems related to the study of algebraic groups and Lie groups. The first one deals with computation of an invariant called the genus number of a connected reductive algebraic group over an algebraically closed field and that of a compact connected Lie group. The second problem is about characterisation of real elements in exceptional groups of type F4 defined over an arbitrary field. Let G be a connected reductive algebraic group over an algebraically closed field or a compact connected Lie group. Let ZG(x) denote the centralizer of x ∈ G. Define the genus …
K-Theory Of Quadratic Modules: A Study Of Roy's Elementary Orthogonal Group., A. A. Ambily Dr.
K-Theory Of Quadratic Modules: A Study Of Roy's Elementary Orthogonal Group., A. A. Ambily Dr.
Doctoral Theses
This thesis discusses the K-theory of quadratic modules by studying Roys elementary orthogonal group of the quadratic space Q1H(P) over a commutative ring A. We estab- lish a set of commutator relations among the elementary generators of Roys elementary orthogonal group and use this to prove Quillens local-global principle for this elementary group. We also obtain a result on extendability of quadratic modules. We establish nor- mality of the elementary orthogonal group under certain conditions and prove stability results for the Ki group of this orthogonal group. We also prove that Roys elementary orthogonal group and Petrovs odd hyperbolic unitary …
Bures Distance For Completely Positive Maps And Cp-H-Extendable Maps Between Hilbert C*- Modules., Sumesh K Dr.
Bures Distance For Completely Positive Maps And Cp-H-Extendable Maps Between Hilbert C*- Modules., Sumesh K Dr.
Doctoral Theses
Completely positive (CP-) maps are special kinds of positivity preserving maps on C ∗ -algebras. W.F. Stinespring [Sti55] obtained a structure theorem for CP-maps showing that they are closely connected with ∗-homomorphisms. W. Arveson and other operator algebraists quickly realized the importance of these maps. Presently the role of the theory of CP-maps in our understanding of C ∗ -algebras and von Neumann algebras is well recognised. It has been argued by physicists that CPmaps are physically more meaningful than just positive maps due to their stability under ampliations. From quantum probabilistic point of view CP-maps are quantum analogues of …
Proximinality Properties Of Subspaces And Intersection Properties Of Balls In Banach Spaces., Jayanarayanan C. R. Dr.
Proximinality Properties Of Subspaces And Intersection Properties Of Balls In Banach Spaces., Jayanarayanan C. R. Dr.
Doctoral Theses
In this chapter, we explain the background and the main theme of this thesis and provide a chapter-wise summary of its principal results. We introduce some notations and preliminaries that will be used in the subsequent chapters.Study of proximinality related properties and ball intersection related properties of Banach spaces have been an active area of research in the field of geometry of Banach spaces. In this thesis, we mainly study these two classes of Banach space theoretic properties.We consider only Banach spaces over the real field R and all subspaces we consider are assumed to be closed.1.1 PreliminariesFor a Banach …
Enhancing Effective Depth-Of-Field By Multi-Focus Image Fusion Using Morphological Techniques., Ishita De Ghosh Dr.
Enhancing Effective Depth-Of-Field By Multi-Focus Image Fusion Using Morphological Techniques., Ishita De Ghosh Dr.
Doctoral Theses
A scene to be photographed, usually includes objects at varying distances from the camera. Depth-of-field of a digital camera is the range of distance, all objects within which appear to be sharp in the image. Due to the low depth-of-field of the camera, images acquired by them often suffer from degradation called out-of-foc us blur. One way to enhance the effective depth-of-field is to acquire se veral images of a scene with focus on different parts of it and then combine these images into a single image in such a way that all regions of the scene are in focus. …
Essays On Regular Variations In Classical And Free Setup: Randomaly Weighted Sums, Products In Cevm And Free Subexponentiality., Rajat Subhra Hazra Dr.
Essays On Regular Variations In Classical And Free Setup: Randomaly Weighted Sums, Products In Cevm And Free Subexponentiality., Rajat Subhra Hazra Dr.
Doctoral Theses
In this thesis, we shall be focusing on some problems in probability theory involving regularly varying functions. The theory of regular variations has played an important role in probability theory, harmonic analysis, number theory, complex analysis and many more areas of mathematics. For an encyclopedic treatment of the subject, we refer to Bingham et al. (1987). In probability theory, the limiting behavior of the sums of independent and identically distributed (i.i.d.) random variables is closely related to regular variation. The books by Feller (1971) and Gnedenko and Kolmogorov (1968) give characterizations of random variables in the domains of attraction of …
Some Aspects Of Toric Topology., Soumen Sarkar Dr.
Some Aspects Of Toric Topology., Soumen Sarkar Dr.
Doctoral Theses
The main goal of this thesis is to study the topology of torus actions on manifolds and orbifolds. In algebraic geometry actions of the torus (C * ) n on algebraic varieties with nice properties produce bridges between geometry and combinatorics see [Dan78], [Oda88] and [Ful93]. We see a similar bridge called moment map for Hamiltonian action of compact torus on symplectic manifolds see [Aud91] and [Gui94]. In particular whenever the manifold is compact the image of moment map is a simple polytope, the orbit space of the action. A topological counterpart called quasitoric manifolds, a class of topological manifolds …
Spectral Properties Of Large Dimensional Random Circulant Type Matrices., Koushik Saha Dr.
Spectral Properties Of Large Dimensional Random Circulant Type Matrices., Koushik Saha Dr.
Doctoral Theses
Consider a sequence of matrices whose dimension increases to infinity. Suppose the entries of this sequence of matrices are random. These matrices with increasing dimension are called large dimensional random matrices (LDRM).Practices of random matrices, more precisely the properties of their eigenvalues, has emerged first from data analysis (beginning with Wishart (1928) [132]) and then from statistical models for heavy nuclei atoms (beginning with Wigner (1955) [130]). To insist on its physical applications, a mathematical theory of the spectrum of the random matrices began to emerge with the work of E. P. Wigner, F. J. Dyson, M. L. Mehta, C. …
Simplicial Bredon-Illman Cohomology With Local Coefficients., Debashis Sen Dr.
Simplicial Bredon-Illman Cohomology With Local Coefficients., Debashis Sen Dr.
Doctoral Theses
The notion of cohomology with local coefficients for topological spaces arose with the work of Steenrod [Ste43, Ste99], in connection with the problem of extending sections of a fibration. This cohomology is built on the notion of fundamental groupoid of the space and can be described by the invariant cochain subcomplex of the cochain complex of the universal cover under the action of the fundamental group of the space. This later description is due to Eilenberg [Eil47]. Cohomology with local coefficients finds applications in many other situations.We focus on one such application of this cohomology which is due to S. …
Ball Remotality In Banach Spaces And Related Topics, Tanmoy Paul Dr.
Ball Remotality In Banach Spaces And Related Topics, Tanmoy Paul Dr.
Doctoral Theses
In this work we aim to study Ball Remotality and densely Ball Remotality of subspaces in Banach spaces. We study this property in many classical spaces of type c0, c,\\â„“p and C(K) where K is a compact Hausdorff space. The said problem also discussed for Banach spaces when considered as a subspace in its bidual. It is observed M-ideals in C(K) are densely ball remotal. It is shown that a particular type of M-ideal in A(K) where K is a Choquet simplex is densely ball remotal.
Geometric Invariants For A Class Of Semi-Fredholm Hilbert Modules., Shibananda Biswas Dr.
Geometric Invariants For A Class Of Semi-Fredholm Hilbert Modules., Shibananda Biswas Dr.
Doctoral Theses
One of the basic problem in the study of a Hilbert module H over the ring of polynomials C[z] := C[z1, . . . , zm] is to find unitary invariants (cf. [15,7]) for H. It is not always possible to find invariants that are complete and yet easy to compute. There are very few instances where a set of complete invariants have been identified. Examples are Hilbert modules over continuous functions (spectral theory of normal operator), contractive modules over the disc algebra (model theory for contractive operator) and Hilbert modules in the class Bn for a bounded domain C …
Quantum Stochastic Flows: Trotter Product Formula, Dilations And Quantum Brownian Motion., Biswarup Das Dr.
Quantum Stochastic Flows: Trotter Product Formula, Dilations And Quantum Brownian Motion., Biswarup Das Dr.
Doctoral Theses
Motivated by the major role played by probabilistic models in many areas of science, several quantum (i.e. non-commutative) generalizations of classical probability have been attempted by a number of mathematicians. The pioneering works of K.R. Parthasarathy, L. Accardi, R.L. Hudson, P.A. Meyer and others led to the development of one such non-commutative model called ‘quantum probability’ which has a very rich theory of quantum stochastic calculus a la Hudson and Parthasarathy. Within the framework of quantum stochastic calculus, the ‘grand design’ that engages us is the canonical construction and study of ∗-homomorphic flows (jt)t≥0 on a given C ∗ or …
Study On Algebras With Retractions And Planes Over A Dvr., Prosenjit Das Dr.
Study On Algebras With Retractions And Planes Over A Dvr., Prosenjit Das Dr.
Doctoral Theses
Aim:The main aim of this thesis is to study the following problems:1. For a Noetherian ring R, to find a set of minimal sufficient fibre conditions for an R-algebra with a retraction to R to be an A1-fibration over R.2. To investigate sufficient conditions for a factorial A1-form, with a retraction to the base ring, to be A1.3. To investigate whether planes of the form b(X, Y)Zn – a(X, Y) are co- ordinate planes in the polynomial ring in three variables X, Y and Z over a discrete valuation ring.The 1st problem will be discussed in Chapter 3 entitled Codimension- …
Sequences Of Positive Integers Containing No K-Term Arithmetic Progressions And Smooth Numbers In Short Intervals., Goutam Pal Dr.
Sequences Of Positive Integers Containing No K-Term Arithmetic Progressions And Smooth Numbers In Short Intervals., Goutam Pal Dr.
Doctoral Theses
In my thesis I have worked on two problems:1. On sequences of positive integers containing no k terms in arithmetic progressions.2. On smooth numbers in short intervals.The first two chapters of my thesis deal with the first problem and in the rest of the thesis I have focused on the 2nd problem.In the first chapter of my thesis I have considered the function rk(N) for a fixed k ≥ 3, where, by definition, rk(N) is the cardinality of a maximal subset of N consecutive natural numbers with the property that nork terms of it are in an Arithmetic Progression (A. …
Intersection Numbers, Embedded Spheres And Geosphere Laminations For Free Groups., Suhas Pandit Dr.
Intersection Numbers, Embedded Spheres And Geosphere Laminations For Free Groups., Suhas Pandit Dr.
Doctoral Theses
Topological and geometric methods have played a major role in the study of infinite groups since the time of Poincar´e and Klein, with the work of Nielsen, Dehn, Stallings and Gromov showing particularly deep connections with the topology of surfaces and three-manifolds. This is in part because a surface or a 3-manifold is essentially determined by its fundamental group, and has a geometric structure due to the Poincar´e-K¨obe-Klein uniformisation theorem for surfaces and Thurston’s geometrisation conjecture, which is now a theorem of Perelman, for 3-manifolds.A particularly fruitful instance of such an interplay is the relation between intersection numbers of simple …
Geometric Characterization Of Digital Objects: Algorithms And Applications To Image Analysis., Arindam Biswas Dr.
Geometric Characterization Of Digital Objects: Algorithms And Applications To Image Analysis., Arindam Biswas Dr.
Doctoral Theses
Several problems of characterizing a digital object, and particularly, those related to boundary description, have been studied in this thesis. New algorithms and their applications to various aspects of image analysis and retrieval have been reported. A combinatorial technique for constructing the outer and inner isothetic covers of a digital object has been developed. The resolution of the background 2D grid can be changed by varying the grid spacing, and this procedure can be used to extract shape and topological information about the object. Next, an algorithm has been designed for constructing the orthogonal (convex) hull of a digital object …
Versal Deformations Of Leibniz Algebra., Ashis Mandal Dr.
Versal Deformations Of Leibniz Algebra., Ashis Mandal Dr.
Doctoral Theses
No abstract provided.
Isomorphism Of Schwartz Spaces Under Fourier Transform., Joydip Jana Dr.
Isomorphism Of Schwartz Spaces Under Fourier Transform., Joydip Jana Dr.
Doctoral Theses
Classical Fourier analysis derives much of its power from the fact that there are three function spaces whose images under the Fourier transform can be exactly determined. They are the Schwartz space, the L2 space and the space of all C ∞ functions of compact support. The determination of the image is obtained from the definition in the case of Schwartz space, through the Plancherel theorem for the L 2space and through the Paley-Wiener theorem for the other space.In harmonic analysis of semisimple Lie groups, function spaces on various restricted set-ups are of interest. Among the multitude of these spaces …
Certain Pattern Recognition Tasks Using Genetic Programming., Durga Muni Dr.
Certain Pattern Recognition Tasks Using Genetic Programming., Durga Muni Dr.
Doctoral Theses
No abstract provided.
Studies On Construction And List Decoding Of Codes On Some Towers Of Function Fields., M. Prem Laxman Das Dr.
Studies On Construction And List Decoding Of Codes On Some Towers Of Function Fields., M. Prem Laxman Das Dr.
Doctoral Theses
In everyday life, there arise many situations where two parties, sender and receiver, need to communicate. The channel through which they communicate is assumed to be binary symmetric, that is, it changes 0 to 1 and vice versa with equal probability. At the receiver’s end, the sent message has to be recovered from the corrupted received word using some reasonable mechanism. This real life problem has attracted a lot of research in the past few decades. A solution to this problem is obtained by adding redundancy in a systematic manner to the message to construct a codeword. The collection of …
Homogeneous Operators In The Cowen-Douglas Class., Subrata Shyam Roy Dr.
Homogeneous Operators In The Cowen-Douglas Class., Subrata Shyam Roy Dr.
Doctoral Theses
Although, we have used techniques developed in the paper of Cowen-Douglas [18, 20], a systematic account of Hilbert space operators using a variety of tools from several different areas of mathematics is given in the book [26]. This book provides, what the authors call, a sheaf model for a large class of commuting Hilbert space operators. It is likely that these ideas will play a significant role in the future development of the topics discussed here.
Spectral Analysis And Synthesis For Radial Sections Of Homogenous Vector Bundles On Certain Noncompath Riemannian Symmetric Spaces., Sanjoy Pusti Dr.
Spectral Analysis And Synthesis For Radial Sections Of Homogenous Vector Bundles On Certain Noncompath Riemannian Symmetric Spaces., Sanjoy Pusti Dr.
Doctoral Theses
We consider two classical theorems of real analysis which deals with translation invariant subspaces of integrable and smooth functions on R respectively. The first one is a theorem of Norbert Wiener [63] which states that if the Fourier transform of a function f ∈ L 1 (R) has no real zeros then the finite linear combinations of translations f(x − a) of f with complex coefficients form a dense subspace in L 1 (R), equivalently, span{g ∗ f | g ∈ L 1 (R)} is dense in L 1 (R). This theorem is well known as the Wiener-Tauberian Theorem (WTT). …
Web Surfer Models: Preprocessing, Page Ranking, And Quantitative Evaluation., Narayan L. Bhamidipati Dr.
Web Surfer Models: Preprocessing, Page Ranking, And Quantitative Evaluation., Narayan L. Bhamidipati Dr.
Doctoral Theses
The World Wide Web [12] (usually referred to as the Web, WWW or W3) is an enormous collection of data available over the Internet, which is a vast network of computers. It was created in the year 1990 by Tim Berners-Lee, while he worked at CERN, Switzerland, and was made available over the Internet in 1991. The World Wide Web Consortium [136] authoritatively defines the Web as the universe of network-accessible information, the embodiment of human knowledge. The Web consists of objects, also called documents or pages in a generic sense, that are identified using a Uniform Resource Identifier (URI), …
Predictability In The Indian Stock Market: A Study From An Econometric Perspective., Debabrata Mukhopadhyay Dr.
Predictability In The Indian Stock Market: A Study From An Econometric Perspective., Debabrata Mukhopadhyay Dr.
Doctoral Theses
No abstract provided.
Contributions To Random Energy Models., Nabin Kumar Jana Dr.
Contributions To Random Energy Models., Nabin Kumar Jana Dr.
Doctoral Theses
In this introductory chapter, we begin with a brief description of spin glasses in section 1. We are not physicists. The purpose of this section is to trace the history of the models. Section 2 gives a brief summary of the thesis and section 3 recalls certain known facts which will be used later in the thesis.Origin of the problem The models considered in this thesis have their origin in spin glass theory. Roughly, spin glass is a glassy state in a spin system or a disordered material exhibiting high magnetic frustration. The origin of this behavior can be either …
Algorithms For Some Geometric Facility Location And Path Planning Problems., Sasanka Roy Dr.
Algorithms For Some Geometric Facility Location And Path Planning Problems., Sasanka Roy Dr.
Doctoral Theses
The facility location problem is a resource allocation problem that mainly deals with adequate placement of various types of facilities to serve a distributed set of demands satisfying the nature of interactions between the demands and facilities and optimizing the cost of placing/maintaining the facilities and the quality of services.The facility location problem is well-studied in the Operations Research literature and recently has received a lot of attention in the Computer Science community. For a company, the facility location problem provides more strategic decisions than just giving importance to locate the lowest cost space for storing its products. While identifying …
Geometric Primitives In Digital Images: Analyses And Applications Using Digital Geometry., Partha Bhowmick Dr.
Geometric Primitives In Digital Images: Analyses And Applications Using Digital Geometry., Partha Bhowmick Dr.
Doctoral Theses
No abstract provided.
Some Necessary Conditions Of Boolean Functions To Resist Algebraic Attacks., Deepak Dalai Dr.
Some Necessary Conditions Of Boolean Functions To Resist Algebraic Attacks., Deepak Dalai Dr.
Doctoral Theses
No abstract provided.