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Semantic-oriented Architectures and Use of Ontology for Organizing Adaptive Search in Digital Libraries
http://hdl.handle.net/10525/3414
Title: Semantic-oriented Architectures and Use of Ontology for Organizing Adaptive Search in Digital Libraries<br/><br/>Authors: Turnina, Albena<br/><br/>Abstract: Over time, the number of knowledge systems is growing and gaining popularity in various fields such as business, science, training, and etc. Their use has been particularly beneficial for the learning process. The use of a digital library is growing over time because the information stored and delivered is reliable, structured and ready to use. Learners not always have necessary knowledge and skills to search for information in a digital library, as their experience in the information space is limited. This necessitates the development of functionalities that facilitate the process of search in a digital library, like semantic-based search, multi-criteria search, contextual search, adaptive search, and etc. The article presents the architecture of a Functional Module for Adaptive Search in a digital library and its main components. The basic scheme of adaptive and customizable logic is also presented. The article ends with directions for future development of the architecture.ACM Computing Classification System (1998): H.3.7, K.3.1.Review of Policy Envisions and Requirements for STEM Teachers in Bulgaria
http://hdl.handle.net/10525/3413
Title: Review of Policy Envisions and Requirements for STEM Teachers in Bulgaria<br/><br/>Authors: Nikolova, Nikolina; Mihnev, Pencho; Zafirova-Malcheva, Temenuzhka; Stefanova, Eliza; Stefanov, Krassen<br/><br/>Abstract: The article precents a review of the normative framework in Bulgaria related to the development of STEM teachers’ competences. It studies explicitly defined requirements: pedagogical, academic, administrative and communicative competences, as well as implicitly defined ones, integrated in National Educational Standards and students’ curricula: research, team work, ICT, work on a project, management of inquiry-based learning, etc.The authors identify dimensions and aspects of STEM teachers’ competences, set out the major issues for consideration in providing teachers’ training, and formulate six Key messages to providers of STEM teachers’ trainings and policy makers, related to forms, content, approaches and responsibilities of institutions.The goal of the research is for the results to be used in European computer-assisted blended learning teacher trainings. They provide requirements to the training design as well as to the software platforms for implementations of trainings.ACM Computing Classification System (1998): K.3.1.Towards Automatic Generation of Serious Maze Games for Education
http://hdl.handle.net/10525/3412
Title: Towards Automatic Generation of Serious Maze Games for Education<br/><br/>Authors: Bontchev, Boyan; Panayotova, Radina<br/><br/>Abstract: Serious games based on video mazes can be easily and effectively applied for learning purposes with the goal of facilitating technology-enhanced education. In order to practice game-based learning for various curriculums, educators need software platforms for automatized construction and flexible customization of such games. This article presents an open software platform named Maze Builder built on Unity 3D, which is especially designed for automatic generation and easy modification of maze video games. We discuss the maze game design process, the platform architecture and its data model, the results obtained from the performance tests, and a practical experiment conducted with teachers using the platform for generating maze games with educational tasks embedded into maze rooms. The initial results acquired from these experiments are very positive and encouraging with regard of the usability of the Maze Builder platform by domain specialists who are not IT professionals.ACM Computing Classification System (1998): D.2.6, D.2.10, K.8.0.Supporting European Energy Consumers through Gamification and Competence-based Learning
http://hdl.handle.net/10525/3411
Title: Supporting European Energy Consumers through Gamification and Competence-based Learning<br/><br/>Authors: Pancheva, Katina; Antonova, Albena; Stefanov, Krassen; Georgiev, Atanas; Mihnev, Pencho; Malcheva, Temenujka<br/><br/>Abstract: The European energy market liberalization strategy aims to assign a new role to consumers and end-users’ communities so that they can become active participants on the energy market. In this paper we present the project SOCIALENERGY, EU-funded under the H2020 program. This project aims to promote the EU energy market transformation policy and to deliver supporting instruments. By developing innovative ICT-based tools, the project consortium will empower the EU energy consumers to become more energy efficient and competent. Apart from presenting the advanced features of SOCIALENERGY multi-modular platform, we will highlight the importance of the novel competence-based education (CBE) framework to support educational activities and to promote creation of social communities in the energy efficiency domain.ACM Computing Classification System (1998): J.1, K.3.1, K.4.3, K.5.2.Design and Development of Metadata Editors: Datacentric and a User-centric Approaches
http://hdl.handle.net/10525/3410
Title: Design and Development of Metadata Editors: Datacentric and a User-centric Approaches<br/><br/>Authors: Boytchev, Pavel<br/><br/>Abstract: This paper presents the design and the development of two metadata editors for the RAGE project. The work is based on two conceptually different approaches. One of the editors follows a data-centric approach, while the other follows a user-centric one. Discussed are the design challenges, the internal structure and a comparison of both metadata editors.ACM Computing Classification System (1998): H.5.2, H.3.5, J.1, D.2.8.Preface
http://hdl.handle.net/10525/3409
Title: Preface<br/><br/>Authors: Stefanov, Krassen<br/><br/>Abstract: This special issue on Innovations in Education through ICT is the outcome of work carried out at the Centre of Information Society Technologies and the Department of Information Technologies, Faculty of Mathematics and Informatics, St. Kliment Ohridski University of Sofia. It covers the main results obtained from the implementation of several international scientific projects funded by the European Commission (EC).A Web Application for Text Document Classification Based on K-Nearest Neighbor Algorithm
http://hdl.handle.net/10525/3407
Title: A Web Application for Text Document Classification Based on K-Nearest Neighbor Algorithm<br/><br/>Authors: Aleksieva-Petrova, Adelina; Minkov, Emilyan; Petrov, Milen<br/><br/>Abstract: The paper gives insight on how the text document categorizationproblem can be solved and implemented in a software product. On that score, itspecifies how input data are provided, processed and transformed into outputdata. The goal of the paper is not only to suggest a simple theoretical solution tothe text document categorization problem but to provide a real-lifeimplementation as part of a software system.ACM Computing Classication System (1998): H.3.3, H.3.5, I.7.5.How to Account for the Uncertainty in The QoS Selection Task
http://hdl.handle.net/10525/3406
Title: How to Account for the Uncertainty in The QoS Selection Task<br/><br/>Authors: Georgieva, Olga<br/><br/>Abstract: The paper presents an approach to QoS selection of webservices. It introduces a theoretical frame and respective applicableselection procedures, in which the solution accounts for the uncertainty ofthe existing metrics data and client preference. Methods of two generalcases are revealed in detail. The first method considers a selection basedon one service quality. The second method assesses the integrated QoS ofinteresting properties. The theoretical analysis is validated throughexperimental investigation of real data of services’ quality metrics.ACM Computing Classification System (1998): H.3.7, K.3.1.Workflows in Dynamic Software Systems
http://hdl.handle.net/10525/3405
Title: Workflows in Dynamic Software Systems<br/><br/>Authors: Yonchev, Hristo; Bontchev, Boyan<br/><br/>Abstract: Business software systems and applications use businessprocess management concepts to organize and automate processes.Incorporating a business process management system in existing businessapplications is a pretty complex task and, as well, is very expensive interms of time and human resources. The article presents a newlyconceived Framework for Dynamic Business Applications - a softwareplatform that allows business users (domain experts) to defne at runtime all business objects that they will work with, their properties,relationships, and restrictions of their business/domain model. This isvery similar to what can be done with business ontologies regardingrepresentation of entities, ideas, and events, along with their propertiesand relations. After defning them, business users can use them topopulate data in the application and later apply this data for dataextraction, analysis, visualization, and reporting.ACM Computing Classifiation Sstem (1998): D.2.2, D.4.1, H.4.1.An Overview of Self-Adaptive Techniques for Microservice Architectures
http://hdl.handle.net/10525/3404
Title: An Overview of Self-Adaptive Techniques for Microservice Architectures<br/><br/>Authors: Baylov, Krasimir; Dimov, Aleksandar<br/><br/>Abstract: Contemporary software systems are continuously growing insize and a large number of users need to deal with new class of problems- complexity and evolution. To overcome this, new technologies andmethods in software engineering emerge. One of them is the architecturalstyle of microservices. It tends to provide solutions, however it introducesadditional complexity in terms of administration, detecting fault behaviorand applying fxes. Self-adaptive systems address the problems ofcomplexity and evolution by providing mechanisms that allow systems torespond to external environmental changes without human interaction.Currently, there is a lack of understanding on how microservices canutilize the notion of self-adaptiveness and in this paper we make anoverview of the current solutions in the feld.ACM Computing Classifiation Sstem (1998): C.2.4, D.2.11.Big Data Research and Application - A Systematic Literature Review
http://hdl.handle.net/10525/3403
Title: Big Data Research and Application - A Systematic Literature Review<br/><br/>Authors: Petrova-Antonova, Dessislava; Ilieva, Sylvia; Pavlova, Irena<br/><br/>Abstract: In the recent years Big Data has become a research topic forboth academia and industry. Given the data value for applications indifferent domains, as well as the business value of the data per se, there isan urgent need for solid end-to-end, data-driven and data-orientedsolutions to guide strategic decisions. Such solutions should include a setof mechanisms for runtime adaptations across the complete data lifecycleof Big Data Value Chain. Thus, advanced data functions enabling data tobe structured, cleaned, stored, aggregated, modelled, processed, andanalyzed are needed.Considering the significant value of Big Data, this paper presents asystematic literature review. Its main goal is to provide a holistic view ofBig Data challenges as a result of a thorough analysis of state-of-the-artresearch and applications.ACM Computing Classification System (1998): Y.1.0, Z.2.1.Preface
http://hdl.handle.net/10525/3402
Title: Preface<br/><br/>Authors: Eskenazi, Avram; Ilieva, Silvia<br/><br/>Abstract: This special issue of Serdica Journal of Computing is dedicated to the10th anniversary of the Department of Software Engineering (DSE) at theFaculty of Mathematics and Informatics (FMI) of the St. Kliment OhridskiUniversity of Sofa. DSE was established in March 2007 and is the youngestdepartment within FMI. It is the frst department in Bulgaria whosecurriculum includes all aspects of the whole life cycle of software systems. DSEwas created to meet the needs of the Bulgarian IT industry for highly qualifedsoftware engineers and to contribute to the development of a stronger andmore modern national economy.Manipulation by Merging and Annexation in Weighted Voting Games
http://hdl.handle.net/10525/2936
Title: Manipulation by Merging and Annexation in Weighted Voting Games<br/><br/>Authors: Slavov, Zdravko; Evans, Christina<br/><br/>Abstract: The problem of manipulation in voting is fundamental and hasreceived attention in recent research in game theory. In this paper, we considertwo cases of manipulation in weighted voting games done by mergingof coalitions into single players and by annexation of a part or all of thevoting weights of another player viewed from two perspectives: of the effectof swings of players and of the role of the Banzhaf power index. We provetwo theorems for manipulation by merging and annexation, and show severalattractive properties in these two processes.ACM Computing Classification System (1998): J.4, I.2.1.Fast Bitwise Implementation of the Algebraic Normal Form Transform
http://hdl.handle.net/10525/2935
Title: Fast Bitwise Implementation of the Algebraic Normal Form Transform<br/><br/>Authors: Bakoev, Valentin<br/><br/>Abstract: The representation of Boolean functions by their algebraic normalforms (ANFs) is very important for cryptography, coding theory andother scientific areas. The ANFs are used in computing the algebraic degreeof S-boxes, some other cryptographic criteria and parameters of errorcorrectingcodes. Their applications require these criteria and parameters tobe computed by fast algorithms. Hence the corresponding ANFs should alsobe obtained by fast algorithms. Here we continue our previous work on fastcomputing of the ANFs of Boolean functions. We present and investigatethe full version of bitwise implementation of the ANF transform.The experimental results show that this implementation ismore than 25 times faster in comparison to the well-known byte-wise ANFtransform.ACM Computing Classification System (1998): F.2.1, F.2.2.Strategic Trade Between Two Countries - Exploring the Case of Partial Local Consumer Protection
http://hdl.handle.net/10525/2934
Title: Strategic Trade Between Two Countries - Exploring the Case of Partial Local Consumer Protection<br/><br/>Authors: Iordanov, Iordan; Vassilev, Andrey<br/><br/>Abstract: The paper develops a dynamic model of trade between twocountries where the trading entities interact in a strategic context. Consumersin both countries are endowed with certain incomes and try to acquireas much as possible of the quantities available on the markets. Consumershave privileged access to some of the good supplied locally, a form of partiallocal protection. Over time, prices are adjusted to respond to the outcomesof trading. For this setup, we prove the existence of Nash equilibria andsimulate the model numerically in Python to illustrate the possibility of obtainingdifferent types of price dynamics depending on the price adjustmentrule used.ACM Computing Classification System (1998): J4, G4, I.6.3.Global Asymptotic Stability of a Functional Differential Model with Time Delay of an Anaerobic Biodegradation Process
http://hdl.handle.net/10525/2933
Title: Global Asymptotic Stability of a Functional Differential Model with Time Delay of an Anaerobic Biodegradation Process<br/><br/>Authors: Borisov, Milen; Dimitrova, Neli; Krastanov, Mikhail<br/><br/>Abstract: We study a nonlinear functional differential model of an anaerobicdigestion process of wastewater treatment with biogas production. Themodel equations of biomass include two different discrete time delays. Amathematical analysis of the model is completed including existence andlocal stability of nontrivial equilibrium points, existence and boundednessof the model solutions as well as global stabilizability towards an admissibleequilibrium point. We propose and apply a numerical extremum seekingalgorithm for maximizing the biogas flow rate in real time.Numerical simulation results are also included.ACM Computing Classification System (1998): D.2.6, G.1.10, J.2.