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An Overview of Modelling Bulgarian Wildland Fire Behaviour by Application of a Mathematical Game Method and WRF-Fire Models
http://hdl.handle.net/10525/1978
Title: An Overview of Modelling Bulgarian Wildland Fire Behaviour by Application of a Mathematical Game Method and WRF-Fire Models<br/><br/>Authors: Dobrinkova, Nina<br/><br/>Abstract: This paper presents the main achievements of the author’s PhD dissertation. The work is dedicated to mathematical and semi-empirical approaches applied to the case of Bulgarian wildland fires. After the introductory explanations, short information from every chapter is extracted to cover the main parts of the obtained results. The methods used are described inbrief and main outcomes are listed. ACM Computing Classification System (1998): D.1.3, D.2.0, K.5.1.A Bimodality Test in High Dimensions
http://hdl.handle.net/10525/1977
Title: A Bimodality Test in High Dimensions<br/><br/>Authors: Palejev, Dean<br/><br/>Abstract: We present a test for identifying clusters in high dimensionaldata based on the k-means algorithm when the null hypothesis is sphericalnormal. We show that projection techniques used for evaluating validity ofclusters may be misleading for such data. In particular, we demonstratethat increasingly well-separated clusters are identified as the dimensionality increases, when no such clusters exist. Furthermore, in a case of truebimodality, increasing the dimensionality makes identifying the correct clusters more difficult. In addition to the original conservative test, we propose a practical test with the same asymptotic behavior that performs well for amoderate number of points and moderate dimensionality. ACM Computing Classification System (1998): I.5.3.Finite Symmetric Functions with Non-Trivial Arity Gap
http://hdl.handle.net/10525/1976
Title: Finite Symmetric Functions with Non-Trivial Arity Gap<br/><br/>Authors: Shtrakov, Slavcho; Koppitz, Jörg<br/><br/>Abstract: Given an n-ary k-valued function f, gap(f) denotes the essential arity gap of f which is the minimal number of essential variables in fwhich become fictive when identifying any two distinct essential variables in f. In the present paper we study the properties of the symmetric functionwith non-trivial arity gap (2 ≤ gap(f)). We prove several results concerningdecomposition of the symmetric functions with non-trivial arity gap withits minors or subfunctions. We show that all non-empty sets of essentialvariables in symmetric functions with non-trivial arity gap are separable. ACM Computing Classification System (1998): G.2.0.The Wiener, Eccentric Connectivity and Zagreb Indices of the Hierarchical Product of Graphs
http://hdl.handle.net/10525/1975
Title: The Wiener, Eccentric Connectivity and Zagreb Indices of the Hierarchical Product of Graphs<br/><br/>Authors: Hossein-Zadeh, S.; Hamzeh, A.; Ashrafi, A.<br/><br/>Abstract: Let G1 = (V1, E1) and G2 = (V2, E2) be two graphs having a distinguished or root vertex, labeled 0. The hierarchical product G2 ⊓ G1of G2 and G1 is a graph with vertex set V2 × V1. Two vertices y2y1 and x2x1 are adjacent if and only if y1x1 ∈ E1 and y2 = x2; or y2x2 ∈ E2 and y1 = x1 = 0. In this paper, the Wiener, eccentric connectivity and Zagreb indices of this new operation of graphs are computed. As an application, these topological indices for a class of alkanes are computed. ACM Computing Classification System (1998): G.2.2, G.2.3.Noun Sense Disambiguation using Co-Occurrence Relation in Machine Translation
http://hdl.handle.net/10525/1974
Title: Noun Sense Disambiguation using Co-Occurrence Relation in Machine Translation<br/><br/>Authors: Choe, Changil; Kim, Hyonil<br/><br/>Abstract: Word Sense Disambiguation, the process of identifying themeaning of a word in a sentence when the word has multiple meanings,is a critical problem of machine translation. It is generally very difficultto select the correct meaning of a word in a sentence, especially when thesyntactical difference between the source and target language is big, e.g.,English-Korean machine translation. To achieve a high level of accuracyof noun sense selection in machine translation, we introduced a statisticalmethod based on co-occurrence relation of words in sentences and appliedit to the English-Korean machine translator RyongNamSan. ACM Computing Classification System (1998): I.2.7.A Mixed Integer Quadratic Programming Model for the Low Autocorrelation Binary Sequence Problem
http://hdl.handle.net/10525/1973
Title: A Mixed Integer Quadratic Programming Model for the Low Autocorrelation Binary Sequence Problem<br/><br/>Authors: Kratica, Jozef<br/><br/>Abstract: In this paper the low autocorrelation binary sequence problem (LABSP) is modeled as a mixed integer quadratic programming (MIQP)problem and proof of the model’s validity is given. Since the MIQP model is semidefinite, general optimization solvers can be used, and converge in a finite number of iterations. The experimental results show that IQP solvers, based on this MIQP formulation, are capable of optimally solving general/skew-symmetric LABSP instances of up to 30/51 elements in a moderate time. ACM Computing Classification System (1998): G.1.6, I.2.8.A Variable Neighborhood Search Approach for Solving the Maximum Set Splitting Problem
http://hdl.handle.net/10525/1972
Title: A Variable Neighborhood Search Approach for Solving the Maximum Set Splitting Problem<br/><br/>Authors: Matic, Dragan<br/><br/>Abstract: This paper presents a Variable neighbourhood search (VNS)approach for solving the Maximum Set Splitting Problem (MSSP). The algorithm forms a system of neighborhoods based on changing the component for an increasing number of elements. An efficient local search procedure swaps the components of pairs of elements and yields a relatively short running time. Numerical experiments are performed on the instances known in the literature: minimum hitting set and Steiner triple systems. Computational results show that the proposed VNS achieves all optimal or best known solutions in short times. The experiments indicate that the VNS compares favorably with other methods previously used for solving the MSSP. ACM Computing Classification System (1998): I.2.8.An Analysis of Colour Semantics in Art Images
http://hdl.handle.net/10525/1937
Title: An Analysis of Colour Semantics in Art Images<br/><br/>Authors: Ivanova, Krassimira<br/><br/>Abstract: The article briefly presents the results achieved by the PhD project R-1875 “Search in Art Image Collections Based on Colour Semantics”, Hasselt University, which finished successfully. The main goals of this work were to provide a detailed analysis of the colour theories, especially on existing interconnections in successful colour combinations, as well as to formalize them in order to implement automated extraction from digitized artworks.<br/><br/>Description: This article presents the principal results of the Ph.D. thesis A Novel Method for Content-Based Image Retrieval in Art Image Collections Utilizing Colour Semantics by KrassimiraIvanova (Institute of Mathematics and Informatics, BAS), successfully defended at Hasselt Uni-versity in Belgium, Faculty of Science, on 15 November 2011.Variable Neighborhood Search for the File Transfer Scheduling Problem
http://hdl.handle.net/10525/1936
Title: Variable Neighborhood Search for the File Transfer Scheduling Problem<br/><br/>Authors: Dražić, Zorica<br/><br/>Abstract: In this paper a file transfer scheduling problem is considered.This problem is known to be NP-hard, and thus provides a challenging areafor metaheuristics. A variable neighborhood search algorithm is designedfor the transfer scheduling of files between various nodes of a network, bywhich the overall transfer times are to be minimized. Optimality of VNSsolutions on smaller size instances has been verified by total enumeration.For several larger instances optimality follows from reaching the elementarylower bound of a problem.<br/><br/>Description: ACM Computing Classification System (1998): I.2.8, G.1.6.An Algorithmic Approach to Inferring Cross-Ontology Links while Mapping Anatomical Ontologies
http://hdl.handle.net/10525/1935
Title: An Algorithmic Approach to Inferring Cross-Ontology Links while Mapping Anatomical Ontologies<br/><br/>Authors: Petrov, Peter; Krachounov, Milko; van Ophuizen, Ernest; Vassilev, Dimitar<br/><br/>Abstract: Automated and semi-automated mapping and the subsequentlymerging of two (or more) anatomical ontologies can be achieved by (at least)two direct procedures.The first concerns syntactic matching between the terms of the two ontologies; in this paper, we call this direct matching (DM). It relies on identitiesbetween the terms of the two input ontologies in order to establish cross-ontology links between them.The second involves consulting one or more external knowledge sourcesand utilizing the information available in them, thus providing additionalinformation as to how terms (concepts) from the two input ontologies arerelated/linked to each other. Each of the two ontologies is aligned to an external knowledge source and links representing synonymy, is-a parent-child,and part-of parent-child relations, are drawn between the ontology and theknowledge source. These links are then run through a set of simple logicalrules in order to come up with cross-ontology links between the two inputontologies. This method is known as semantic matching. It proves useful<br/><br/>Description: ACM Computing Classification System (1998): J.3.A New Method for Computing the Eccentric Connectivity Index of Fullerenes
http://hdl.handle.net/10525/1934
Title: A New Method for Computing the Eccentric Connectivity Index of Fullerenes<br/><br/>Authors: Ghorbani, Modjtaba; Malekjani, Khadijeh<br/><br/>Abstract: The eccentric connectivity index of the molecular graph G, ξ^c (G), was proposed by Sharma, Goswami and Madan. It is defined asξ^c (G) = Σu∈V(G)degG(u) ecc(u), where degG(x) denotes the degree of the vertex x in G and ecc(u) = Max{d(x, u) | x ∈ V (G)}. In this paper this graph invariant is computed for an infinite class of fullerenes by means of group action.<br/><br/>Description: ACM Computing Classification System (1998): G.2.2, G.2.3.A Linear Time Algorithm for Computing Longest Paths in Cactus Graphs
http://hdl.handle.net/10525/1933
Title: A Linear Time Algorithm for Computing Longest Paths in Cactus Graphs<br/><br/>Authors: Markov, Minko; Ionut Andreica, Mugurel; Manev, Krassimir; Tapus, Nicolae<br/><br/>Abstract: We propose an algorithm that computes the length of a longestpath in a cactus graph. Our algorithm can easily be modified to output alongest path as well or to solve the problem on cacti with edge or vertexweights. The algorithm works on rooted cacti and assigns to each vertexa two-number label, the first number being the desired parameter of thesubcactus rooted at that vertex. The algorithm applies the divide-and-conquer approach and computes the label of each vertex from the labels of its children. The time complexity of our algorithm is linear in the number of vertices, thus improving the previously best quadratic time algorithm.<br/><br/>Description: ACM Computing Classification System (1998): G.2.2.Application of Service-Oriented Architecture in Software Quality Management
http://hdl.handle.net/10525/1932
Title: Application of Service-Oriented Architecture in Software Quality Management<br/><br/>Authors: Marinova, Olga<br/><br/>Abstract: This article examines the quality management software processes and offers a model for their automation based on Service-orientedArchitecture. The prerequisites for creating such a solution are analyzed, asare existing automated tools in this area. The possibilities of service-orientedarchitecture are presented along with its advantages in the context of thisresearch on developing a quality management system that will operate effectively against defined requirements, consistently and regardless of the used platform, database management system (DBMS) and other technological features of the applications.<br/><br/>Description: ACM Computing Classification System (1998): D.2.5, D.2.9, D.2.11.A Necessary and Sufficient Condition for the Existence of an (n,r)-arc in PG(2,q) and Its Applications
http://hdl.handle.net/10525/1931
Title: A Necessary and Sufficient Condition for the Existence of an (n,r)-arc in PG(2,q) and Its Applications<br/><br/>Authors: Hamada, Noboru; Maruta, Tatsuya; Oya, Yusuke<br/><br/>Abstract: Let q be a prime or a prime power ≥ 3. The purpose of thispaper is to give a necessary and sufficient condition for the existence ofan (n, r)-arc in PG(2, q ) for given integers n, r and q using the geometricstructure of points and lines in PG(2, q ) for n > r ≥ 3. Using the geometric method and a computer, it is shown that there exists no (34, 3) arc inPG(2, 17), equivalently, there exists no [34, 3, 31] 17 code.<br/><br/>Description: ACM Computing Classification System (1998): E.4.Adaptive E-learning Content Design and Delivery Based on Learning Styles and Knowledge Level
http://hdl.handle.net/10525/1801
Title: Adaptive E-learning Content Design and Delivery Based on Learning Styles and Knowledge Level<br/><br/>Authors: Vassileva, Dessislava<br/><br/>Abstract: The possibility of adaptive learning content delivery in e-learning systems is one of the important factors for highly improving theirquality. Therefore, the application field of adaptive e-learning is relevant and significant. This article presents the main results of a PhD thesis examining various aspects of this area. The aim of the dissertation is to propose a model and a platform architecture of an adaptive e-learning system and a corresponding prototype to be designed, implemented and tested in experimental conditions. On one hand, the developed prototype will assist a learner in accessing and using learning resources which are adapted according to his/her personal characteristics (in this case his/her learning style and level of knowledge). On the other hand, it will facilitate the author of the learning content and course instructor in the creation of appropriate learning objects and applying them to the suitable pedagogical strategies.<br/><br/>Description: ACM Computing Classification System (1998): K.3.1, K.3.2.BPMN Analysis of Public Procurement
http://hdl.handle.net/10525/1800
Title: BPMN Analysis of Public Procurement<br/><br/>Authors: Semerdjieva, Maria; Krastev, Evgeniy<br/><br/>Abstract: This paper formulates a realistic case study of a public procurement process, where the national legal system is taken in consideration.Business Process Modeling Notation (BPMN) is used for encoding processes related to the analysis of public procurement tasks. Critical elements in the public procurement process that affect time, quality and cost are identified at the organizational, process execution and system levels. The main phases of public procurement are described and problems related to each phase are distinguished. A BPMN collaboration diagram is used to show how different participants in a process are related and interact with each other.Choreography diagrams of the latest version of BPMN are being used to model the abstract behavior of the participants in business interactions for the purpose of providing a standard mapping to the Business Process Execution Language for Web Services (BPEL) and enable the execution of this behavior.<br/><br/>Description: ACM Computing Classification System (1998): D.0, D.2.11.