Browsing Mathematics by Title

Vukomanović, Đorđe (Belgrade , 1985)[more][less]
Abstract: The thesis consists of three chapters. In Chapter 1 nonstrict deductive implicative algebras are studied. Weak deductive, ndeductive and ωdeductive implicative algebras are introduced. Two kinds of complements, pseudocomplement and contraposition complement in deductive implicative algebras are defined, and the connection between these algebras and deductive implicative algebras with complement are presented. Certain properties of several implicative filters in implicative algebras and their connections with homomorphsms and congruences of these algebras are studied. In the last part of Chapter 1 the representation theorems for implicative algebras mentioned in the previous parts of the chapter are proved. The strict deductive implicative algebras and their properties, which are analogous to the properties algebras from the first chapter, are studied in Chapter 2. In the last part of that chapter the representation theorems for the strict implicative algebras are proved. In Chapter 3 deductive implicative algebras in the context of deductive (sub)nets are studied. Important notions of different forms of limited distribution and many interesting connections between these distributions and the properties of deductive nets are presented. It is shown that an implicative algebra can be drowned isomorphicaly into finite deductive subnet of sets or a net such that the implication are preserved. URI: http://hdl.handle.net/123456789/40 Files in this item: 1
phdDjordjeVukomanovic.pdf ( 6.744Mb ) 
Vujošević, Biljana (Beograd , 2015)[more][less]
Abstract: In this doctoral dissertation we de ne the index of product systems of Hilbert B B modules over a unital C algebra B. In detail, we prove that the set of all uniformly continuous units on a product system over a C algebra B can be endowed with a structure of leftright Hilbert B B module after identifying similar units by the suitable equivalence relation and we use that construction to de ne the index of a given product system. We prove that such de ned index is a covariant functor from the category of continuous product systems to the category of twosided BB modules. We prove that the index is subadditive with respect to the outer tensor product of product systems and we, also, prove additional properties of the index of product system that can be embedded into a spatial one (a product system that contains a central unital unit). We prove that such de ned index is a generalization of earlier de ned indices by Arveson (in the case B = C) and Skeide (in the case of spatial product systems). We, also, de ne the index of product systems in a di erent way and prove that the new de nition is equivalent to the previous one. Actually, it corresponds to Arveson's original de nition of the index. URI: http://hdl.handle.net/123456789/4235 Files in this item: 1
phdBiljanaVujosevic.pdf ( 14.03Mb ) 
Jovanović, Božidar (Beograd , 1999)[more][less]
URI: http://hdl.handle.net/123456789/4130 Files in this item: 1
Integrabilni_neholonomni.PDF ( 1.700Mb ) 
Shafah, Osama (Belgrade , 2013)[more][less]
Abstract: In this thesis we will give an interesting relation between finite rings and their graphs, such relations are obtained in following way. Consider a directed graph on a finite ring , where are sets of vertices and edges respectively, and defined by . Since is finite, it has an integer characteristic . If is not a prime, then has zero divisors and is not a unique factorization ring, but if it is prime, then nevertheless could have zerodivisors (e.g., ). Let and be relatively prime numbers, such that , ! and define two maps " #, $ by " %& and %& respectively, so " and are homomorphism maps, suppose that '() *+,. / + is a directed cycle of length . in a directed graph , then many interesting algebraic relations will exist between longest cycles in , # and $, which will be shown up in the chapter III. URI: http://hdl.handle.net/123456789/3052 Files in this item: 1
Doctroral_theiss_Osama_Shafah.pdf ( 332.8Kb ) 
Turku, Haljilj (Pristina , 1978)[more][less]

Pažanin, Ratomir (Belgrade , 1980)[more][less]

Lelas, Nikola (Beograd , 2022)[more][less]
Abstract: The subject of the dissertation is the problem of simultaneous nonvanishing of quadratic twists of elliptic curve 𝐿functions and quadratic Dirichlet 𝐿functions (and their derivatives) at the centar point 𝑠 = 1 2 , in the situation when these objects are defined over the rational function field over finite field F𝑞. For each monic polynomial 𝐷 ∈ F𝑞 [𝑡], there is a corresponding quadratic Dirichlet character 𝜒𝐷. Associated to such character, there is the corresponding Dirichlet 𝐿 function 𝐿(𝑠, 𝜒𝐷), as well as the quadratic twist 𝐸 ⊗ 𝜒𝐷 of a fixed elliptic curve 𝐸/F𝑞 (𝑡), whose 𝐿function is denoted by 𝐿(𝑠, 𝐸 ⊗ 𝜒𝐷). A lower bound for the number of polynomials 𝐷 ∈ H∗ 2𝑔+1 such that 𝐿 URI: http://hdl.handle.net/123456789/5532 Files in this item: 1
Disertacija_nikola_lelas.pdf ( 2.523Mb ) 
Mitrinović, Dragoslav (Beograd , 1933)[more][less]

Jaćimović, Milojica (Belgrade)[more][less]

Alimpić, Branka (Belgrade)[more][less]

Prešić, Marica (Belgrade)[more][less]

Krstev, Cvetana (Beograd , 1997)[more][less]

Marinković, Silvana (Kragujevac, Serbia , 2011)[more][less]
Abstract: In this dissertation functions and equations in some classes of lattices such as Post algebras, Stone algebras and multiplevalued logics, are studied. The dissertation, beside Preface and References with 46 items, consists of five chapters. In Introduction some basic notations which will be used in next chapters are given. Main results on Boolean functions and equations are exposed in Chapter 2. In Chapter 3, assuming that a general solution is known, the class of reproductive general solutions of the equation in Stone algebra is described. All general solutions of equations in one variable in multiplevalued logic are described in Chapter 4. A necessary and sufficient conditions that given sequence of recurrent inequalities represents solution of some consistent Post equation are given in Chapter 5. Also, it is proved that every Post transformation is the parametric solution of some consistent Post equation. URI: http://hdl.handle.net/123456789/1842 Files in this item: 1
SilvanaMarinkovicDoktorat.pdf ( 360.3Kb ) 
Stipanić, Ernest (Belgrade)[more][less]

Dacić, Rade (Belgrade , 1965)[more][less]

Mitrović, Slobodanka (Belgrade)[more][less]

Lipkovski, Aleksandar (Belgrade , 1985)[more][less]
URI: http://hdl.handle.net/123456789/25 Files in this item: 1
phdAleksandarLipkovski.pdf ( 2.471Mb ) 
Miličić, Miloš (Belgrade , 1982)[more][less]

Malinović, Todor (Novi Sad , 1986)[more][less]

Obradović, Marko (Beograd , 2015)[more][less]
Abstract: First characterizations of probability distributions date to the thirties of last century. This area, which lies on the borderline of probability theory and mathematical statistics, attracts large number of researchers, and in recent times the number of papers on the subject is increasing. Goodnessof t tests are among the most important nonparametric tests. Many of them are based on empirical distribution function. The application of characterization theorems for construction of goodnessof t tests dates to the middle of last century, and recently has become one of the main directions in this eld. The advantage of such tests is that they are often free of distribution parametres and hence enable testing of composite hypotheses. The goals of this dissertation are the formulation of new characterizations of exponential and Pareto distribution, as well as the application of the theory of Ustatistics, large deviations and Bahadur e ciency to construction and examination of asymptotics of goodnessof t tests for aforementioned distributions. The dissertation consists of six chapters. In the rst chapter a review of di erent types of characterizations is presented, pointing out their abundance and variety. The special emphasis is given to the characterizations based on equidistribution of functions of the sample. Besides, two new characterizations of Pareto distribution are presented. The second chapter is devoted to some new characterizations of the exponential distributions presented in papers [65] and [53]. Six characterizations based on order statistics are presented. A special case of one of them (theorem 2.4.3) represents the solution of open problem stated by Arnold and Villasenor [9]. In the third chapter there are basic concepts on Ustatistics, the class of statistics important in the theory of unbiased estimation. Some of their asymptotic properties are given. Uempirical distribution functions, a generalization of standard empirical distribution functions, are also de ned. The fourth chapter is dedicated to the asymptotic e ciency of statistical tests, primarily to Bahadur asymptotic e ciency, i.e. asymptotic e ciency of the test when the level of signi cance approaches zero. Some theoretical results from the monograph by Nikitin [57], and papers [61], [59], etc. are shown. In the fth chapter new results in the eld of goodnessof t tests for Pareto distribution are presented. Based on three characterizations of Pareto distribution given in section 1.1.2. six goodnessof t tests, three of integral, and three of Kolmogorov type, are proposed. In each case the composite null hypothesis is tested since the test statistics are free of the parameter of Pareto distribution. For each test the asymptotic distribution under null hypothesis, as well as asymptotic behaviour of the tail (large deviations) under close alternatives is derived. For some standard alternatives, the local Bahadur asymptotic e ciency is calculated and the domains of local asymptotic optimality are obtained. The results from this chapter are published in [66] and [64]. The sixth chapter brings new goodnessof t tests for exponential distribution. Based on the solved hypothesis of Arnold and Villasenor two classes of tests, integral and Kolmogorov type, are proposed, depending on the number of summands in the characterization. The study of asymptotic properties, analogous to the ones in the fth chapter is done in case of two and three summands, for which the tests have practical importance. The results of this chapter are presented in [39]. URI: http://hdl.handle.net/123456789/4288 Files in this item: 1
phdObradovicMarko.pdf ( 789.3Kb )