"Scientific research" Almanac

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  DEEP NEURAL NETWORKS FOR DETECTION OF CREDIT CARD FRAUD

  This publication presents research on the possibility of using Deep Neural Net-works (DNNs) for detection of credit card fraud. The research is based on an open da-taset and aims to determine how the varying number of hidden layers and other archi-tectural parameters (width of each layer, activation functions) affects training and predictive ... This publication presents research on the possibility of using Deep Neural Net-works (DNNs) for detection of credit card fraud. The research is based on an open da-taset and aims to determine how the varying number of hidden layers and other archi-tectural parameters (width of each layer, activation functions) affects training and predictive potential of the network. It also aims to determine how to use generative-adversarial approach efficiently in order to overcome the problem with the imbalance between legitimate and fraudulent transactions, which is crucial characteristic of the datasets related to detection of credit card fraud. The publication presents the results of various experiments, conducted to achieve the stated goals. A number of experiments have been carried out combining network training of various depth of the network and with different parameters of the learning process, for example, activation function and dropout values. The experiments focus on using generative-adversarial approach as a method for oversampling, in par-ticular. The results indicate that deep neural networks with moderate hidden layers, combined with methods for oversampling are performing much better in identifying fraudulent transactions than the classical neural networks, consisting of only one hid-den layer. The results also indicate that using generative-adversarial approach as a method for oversampling is comparable in efficiency to other widely used techniques.

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  EVALUATION OF CONVERGENCE IN SOCIAL PROTECTION EXPENDITURE IN THE EUROPEAN UNION

  The purpose of this paper is to evaluate the degree of convergence across the EU Member States in social protection expenditure for the period 2008-2016 by using statistical and econometric approaches for measuring convergence. This is achieved by accomplishing several tasks: presentation of theoretical concepts and statistical and econometric ... The purpose of this paper is to evaluate the degree of convergence across the EU Member States in social protection expenditure for the period 2008-2016 by using statistical and econometric approaches for measuring convergence. This is achieved by accomplishing several tasks: presentation of theoretical concepts and statistical and econometric approaches for convergence evaluation; exploring the convergence process through the club convergence approach; exploring the convergence process through the beta-convergence approach across European Union Member States as a whole, and between countries in individual convergence clubs; analysis of the impact of structural variables on social protection expenditure and the cohesion process. The thesis defended by the author is that by using the applied approaches for the study of the club convergence and beta-convergence, an adequate evaluation of the degree of convergence of the EU Member States is achieved. This makes it possible to establish the rate of convergence to the general equilibrium both within the European Union and within separate convergence clubs. As a result of the study of club convergence, convergence clubs, clubs in a process of transitional divergence, as well as countries that are not involved in that process are identified. The study of beta-convergence shows a process of reducing disparities in convergence clubs and the European Union as a whole. The findings of the study indicate that the additional variables in the models of conditional beta-convergence have a significant impact on the increase in the social protection expenditure and the cohesion process. EU countries converge at a faster pace into the general equilibrium level of social protection expenditure when it is presented as a percentage of Gross Domestic Product.

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  AGILE PROJECT MANAGEMENT IN PUBLIC SECTOR ORGANIZATIONS

  One of the latest approaches to improve the operations of business organizations is the Agile Project Management. It emerged in the software industry in 2001, but gradually entered other, non-software industries. However, the transfer of the approach to the public sector requires a specific transformation of the Agile methodology, insofar as the ... One of the latest approaches to improve the operations of business organizations is the Agile Project Management. It emerged in the software industry in 2001, but gradually entered other, non-software industries. However, the transfer of the approach to the public sector requires a specific transformation of the Agile methodology, insofar as the two sectors are radically different. The purpose of this study is to present a methodology for agile project management in the public sector in Bulgaria and to define the conditions and barriers for its effective implementation in public sector organizations. The tasks of the research are the following: 1) scientific literature research and critical analysis related to the object of the study; 2) developing a methodology for agile project management in the public sector; 3) approbation of the methodology and definition of the conditions for its implementation. The thesis of the research states that agile project management methodology can be adapted and integrated into public sector practice, although further efforts are needed to create organizational sensitivity to implement this approach. As a result of the study, a methodology for agile project management in the public sector in Bulgaria has been developed, which includes basic principles, specific roles and preconditions. Three stages of the methodology are formed, each with steps and iterations that are visualized through a process map. The conditions and barriers to the implementation of the methodology in public sector organizations are outlined.