DSpace Collection: Mathematica Balkanica New Series, Vol. 24, 2010, Fasc. 3-4
http://hdl.handle.net/10525/1332
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Classification of Smoking Cessation Status Using Various Data Mining Methods
http://hdl.handle.net/10525/1349
Title: Classification of Smoking Cessation Status Using Various Data Mining Methods<br/><br/>Authors: Kartelj, Aleksandar<br/><br/>Abstract: This study examines different approaches of binary classification applied to the prob-lem of making distinction between former and current smokers. Prediction is based on datacollected in national survey performed by the National center for health statistics of Americain 2000. The process consists of two essential parts. The first one determines which attributesare relevant to smokers status, by using methods like basic genetic algorithm and differentevaluation functions [1]. The second part is a classification itself, performed by using methodslike logistic regression, neural networks and others [2]. Solving these types of problems has itsreal contributions in decision support systems used by some health institutions.<br/><br/>Description: AMS Subj. Classification: 62P10, 62H30, 68T01Splines in Numerical Integration
http://hdl.handle.net/10525/1348
Title: Splines in Numerical Integration<br/><br/>Authors: Udovičić, Zlatko<br/><br/>Abstract: We gave a short review of several results which are related to the role of splines(cardinal, centered or interpolating) in numerical integration. Results deal with the problemof approximate computation of the integrals with spline as a weight function, but also withthe problem of approximate computation of the integrals without weight function. Besides, wepresented an algorithm for calculation of the coefficients of the polynomials which correspondto the cardinal B-spline of arbitrary order and described five methods for calculation of themoments in the case when cardinal B-spline of order m,m ∈ N, is a weight function.<br/><br/>Description: AMS Subj. Classification: 65D07, 65D30.Canonical Objects in Classes of (n, V)-Groupoids
http://hdl.handle.net/10525/1347
Title: Canonical Objects in Classes of (n, V)-Groupoids<br/><br/>Authors: Celakoska-Jordanova, Vesna<br/><br/>Abstract: Free algebras are very important in studying classes of algebras, especially varietiesof algebras. Any algebra that belongs to a given variety of algebras can be characterized as ahomomorphic image of a free algebra of that variety. Describing free algebras is an importanttask that can be quite complicated, since there is no general method to resolve this problem.The aim of this work is to investigate classes of groupoids, i.e. algebras with one binaryoperation, that satisfy certain identities or other conditions, and look for free objects in suchclasses.<br/><br/>Description: AMS Subj. Classification: 03C05, 08B20New Vacuum Solutions for Quadratic Metric-Affine Gravity - a Metric Affine Model for the Massless Neutrino?
http://hdl.handle.net/10525/1346
Title: New Vacuum Solutions for Quadratic Metric-Affine Gravity - a Metric Affine Model for the Massless Neutrino?<br/><br/>Authors: Pasic, Vedad<br/><br/>Abstract: In this paper we present an overview of our research that was presented at theMASSEEInternational Congress on Mathematics MICOM 2009 in Ohrid, Macedonia. We deal withquadratic metric–affine gravity, which is an alternative theory of gravity. We present newvacuum solutions for this theory and an attempt to give their physical interpretation on thebasis of comparison with existing classical models. These new explicit vacuum solutions ofquadratic metric–affine gravity are constructed using generalised pp-waves. A classical pp-wave is a 4-dimensional Lorentzian spacetime which admits a non–vanishing parallel spinorfield. We generalise this definition to metric compatible spacetimes with torsion, describe basicproperties of such spacetimes and eventually use them to construct new solutions to the fieldequations of quadratic metric–affine gravity. The physical interpretation of these solutions wepropose is that these new solutions represent a conformally invariant metric–affine model forthe massless neutrino. We give a comparison with a classical model describing the interactionof gravitational and massless neutrino fields, namely Einstein-Weyl theory. Future researchtopics are briefly discussed.<br/><br/>Description: AMS Subj. Classification: 83C15, 83C35Nonlinear Spectral Theories and Solvability of Nonlinear Hammerstein Equations
http://hdl.handle.net/10525/1345
Title: Nonlinear Spectral Theories and Solvability of Nonlinear Hammerstein Equations<br/><br/>Authors: Halilović, Sanela<br/><br/>Abstract: We study some possibilities of nonlinear spectral theories for solving nonlinearoperator equations. The main aim is to research a spectrum and establish somekind of nonlinear Fredholm alternative for Hammerstein operator KF.<br/><br/>Description: AMS Subj. Classification: 47J10, 47H30, 47H10Services on Application Level in Grid for Scientific Calculations
http://hdl.handle.net/10525/1344
Title: Services on Application Level in Grid for Scientific Calculations<br/><br/>Authors: Goranova, Radoslava<br/><br/>Abstract: The Grid is a hardware and software infrastructure that coordinates access to distribute computational and data resources, shared by different institutes, computational centres and organizations. The Open Grid Services Architecture (OGSA) describes an architecture for aservice-oriented grid computing environment, based on Web service technologies, WSDL and SOAP. In this article we investigate possibilities for realization of business process composition in grid environment, based on OGSA standard.<br/><br/>Description: AMS Subj. Classification: 00-02, (General)Mathematical Optimization for the Train Timetabling Problem
http://hdl.handle.net/10525/1343
Title: Mathematical Optimization for the Train Timetabling Problem<br/><br/>Authors: Stanojević, Predrag; Marić, Miroslav; Kratica, Jozef; Bojović, Nebojša; Milenković, Miloš<br/><br/>Abstract: Rail transportation is very rich in terms of problems that can be modelled and solved using mathematical optimization techniques. The train scheduling problem as the most important part of a rail operating policy has a very significant impact on a rail company profit considering the fact that from the quality of a train timetable depends a flow of three most important resources on rail network: cars, locomotives and crews. The train timetabling problem aims at determining a periodic timetable for a set of trains that does not violate track capacities and satisfies some operational constraints. In this paper, we developed an integer programming approach for determining an optimal train schedule for a single, one-way track linking two major stations, with a number of intermediate stations between. The application has been tested on a realistic example suggested by the PE “Serbian Railways”. Obtained results show a potential for a practical application of proposed approach.<br/><br/>Description: AMS Subj. Classification: 90C57; 90C10;File Format for Storage of Multimedia Information
http://hdl.handle.net/10525/1342
Title: File Format for Storage of Multimedia Information<br/><br/>Authors: Armyanov, Peter<br/><br/>Abstract: This article studies problems referring to storage, editing and streaming vector graphicsand animation. The advantages and disadvantages of existing formats are reviewed and somesuggestions to solve the problems are given. An approach for generating vector stream in aformat, that allows embedding of additional media such audio and descriptive meta data isintroduced. In parallel the problem of conversion multimedia files from one container formatto another is described and solution for virtual conversion, based on file system filtering ismentioned. The ways for future development are pointed and some improvements of workalready done are suggested.<br/><br/>Description: AMS Subj. Classification: 68U05, 68P30Organization and Security of the Audio and Video Archive for Unique Bulgarian Bells
http://hdl.handle.net/10525/1341
Title: Organization and Security of the Audio and Video Archive for Unique Bulgarian Bells<br/><br/>Authors: Noev, Nikolay<br/><br/>Abstract: The purpose of this investigation is to study and to identify the most valuable uniquebells as well as to develop a digital archive with the help of advanced technologies. The maintasks are: development of the audio archive of information gathered from artifacts, analysis,optimization and addition of metadata for indexing of digital data, compression and dataprotection, prevention of data loss, design, organization and maintenance of archive. Weinvestigate the methods of protection with watermarking which can be used against illegal useof data. We create and protect samples for additional applications and web sites.<br/><br/>Description: AMS Subj. Classification: H.3.7 Digital Libraries, K.6.5 Security and ProtectionMultiplicative Systems on Ultra-Metric Spaces
http://hdl.handle.net/10525/1340
Title: Multiplicative Systems on Ultra-Metric Spaces<br/><br/>Authors: Memic, Nacima<br/><br/>Abstract: We perform analysis of certain aspects of approximation in multiplicative systemsthat appear as duals of ultrametric structures, e.g. in cases of local fields, totally disconnectedAbelian groups satisfying the second axiom of countability or more general ultrametric spacesthat do not necessarily possess a group structure. Using the fact that the unit sphere of alocal field is a Vilenkin group, we introduce a new concept of differentiation in the field ofp-adic numbers. Some well known convergence tests are generalized to unbounded Vilenkingroups, i.e. to the setting where the standard boundedness assumption related to the sequenceof subgroups generating the underlying topology is absent. A new Fourier multiplier theoremfor Hardy spaces on such locally compact groups is obtained. The strong Lq, q > 1, and weakL1 boundedness of Fourier partial sums operators in the system constructed on more generalultrametric spaces is proved.<br/><br/>Description: AMS Subj. Classification: MSC2010: 42C10, 43A50, 43A75A Metaheuristic Approach to Solving the Generalized Vertex Cover Problem
http://hdl.handle.net/10525/1339
Title: A Metaheuristic Approach to Solving the Generalized Vertex Cover Problem<br/><br/>Authors: Milanović, Marija<br/><br/>Abstract: The topic is related to solving the generalized vertex cover problem (GVCP) by geneticalgorithm. The problem is NP-hard as a generalization of well-known vertex cover problemwhich was one of the first problems shown to be NP-hard. The definition of the GVCP andbasics of genetic algorithms are described. Details of genetic algorithm and numerical resultsare presented in [8]. Genetic algorithm obtained high quality solutions in a short period oftime.<br/><br/>Description: AMS Subj. Classification: 90C27, 05C85, 90C59Semi-Smooth Newton Methods for the Time Optimal Control of Nonautonomous Ordinary Differential Equations
http://hdl.handle.net/10525/1338
Title: Semi-Smooth Newton Methods for the Time Optimal Control of Nonautonomous Ordinary Differential Equations<br/><br/>Authors: Rubeša, Jelena; Kunisch, Karl<br/><br/>Abstract: The control problem of minimal time transition between two stationary points areformulated in a framework of an indirect numerical method. The problem is regularized andthe monotone behavior of the regularisation procedure is investigated. Semi-smooth Newtonmethod applied on the regularized problems converge superlinearly and usually produce a veryaccurate solution. Differently from other methods, this one does not need a-priory knowledge ofthe control switching structure. A code was developed in the C++ language and the NVIDIACUDA technology made it even faster.<br/><br/>Description: AMS Subj. Classification: 49J15, 49M15Integral Representations of the Logarithmic Derivative of the Selberg Zeta Function
http://hdl.handle.net/10525/1337
Title: Integral Representations of the Logarithmic Derivative of the Selberg Zeta Function<br/><br/>Authors: Gušić, Dženan<br/><br/>Abstract: We point out the importance of the integral representations of the logarithmic derivative of the Selberg zeta function valid up to the critical line, i.e. in the region that includes the right half of the critical strip, where the Euler product definition of the Selberg zeta function does not hold. Most recent applications to the behavior of the Selberg zeta functions associated to a degenerating sequence of finite volume, hyperbolic manifolds of dimension 2 and 3 are surveyed. The research problem consists in extending this kind of integral representations to the setting of the locally symmetric spaces of rank 1.<br/><br/>Description: AMS Subj. Classification: MSC2010: 11F72, 11M36, 58J37Modeling Pulsatility in the Human Cardiovascular System
http://hdl.handle.net/10525/1336
Title: Modeling Pulsatility in the Human Cardiovascular System<br/><br/>Authors: de los Reyes V, Aurelio; Kappel, Franz<br/><br/>Abstract: In this study we investigated, modified and combined two existing mathematical cardiovascular models, a non-pulsatile global model and a simplified pulsatile left heart model. The first goal of the study was to integrate these models. The main objective is to have a global lumped parameter pulsatile model that predicts the pressures in the systemic and pulmonary circulation, and specifically the pulsatile pressures in the the finger arteries where real-time measurements can be obtained. Modifications were made in the ventricular elastance to model the stiffness of heart muscles under stress or exercise state. The systemic aorta compartment is added to the combined model. A finger artery compartment is included to reflect measurements of pulsatile pressures. Parameters were estimated to simulate an average normal blood pressures. Preliminary simulation results are presented.<br/><br/>Description: AMS Subj. Classification: 92C30On Li’s Coefficients for Some Classes of L-Functions
http://hdl.handle.net/10525/1335
Title: On Li’s Coefficients for Some Classes of L-Functions<br/><br/>Authors: Odžak, Almasa<br/><br/>Abstract: We study the generalized Li coefficients associated with the class S♯♭of functions containing the Selberg class and (unconditionally) the class of all automorphic L-functions attached to irreducible unitary cuspidal representations of GLN(Q) and the class of L-functions attached to the Rankin-Selberg convolution of two unitary cuspidal automorphic representations π and π′ of GLm(AF ) and GLm′ (AF ). We deduce a full asymptotic expansion of the Archimedean contribution to these coefficients and investigate the contribution of the non-archimedean term. Obtained results are applied to automorphic L-functions. Also, a bound towards a generalized Ramanujan conjecture for the Archimedean Langlands parameters µπ(v, j) of π is derived.<br/><br/>Description: AMS Subj. Classification: 11M41, 11M26, 11S40Cryptographic Primitives with Quasigroup Transformations
http://hdl.handle.net/10525/1334
Title: Cryptographic Primitives with Quasigroup Transformations<br/><br/>Authors: Mileva, Aleksandra<br/><br/>Abstract: The intention of this research is to justify deployment of quasigroups in cryptography,especially with new quasigroup based cryptographic hash function NaSHA as a runner inthe First round of the ongoing NIST SHA-3 competition. We present new method for fastgeneration of huge quasigroup operations, based on the so-called extended Feistel networks andmodification of the Sade’s diagonal method. We give new design of quasigroup based familyof cryptographic hash functions - NaSHA, which deploy the new method and with a novelapproach - different quasigroups for every application of component quasigroup transformationsin every iteration of the compression function and, much more, the used quasigroups arefunctions of the processed message block.<br/><br/>Description: AMS Subj. Classification: Primary 20N05, Secondary 94A60