1,740 research outputs found
Deset godini proporcyonalno danăno oblagane v Bălgarija : vreme za ravnosmetka
No full textPlamen Dimitrov, Ljuboslav KostovLiteraturverzeichnis Seite 14Text bulgarischKyrillisc
Giving and receiving: effects of labour emigration on the Bulgarian labour market
Get PDFPlamen Dimitrov of the Bulgarian trade union confederation, CITUB, assesses the pros and cons of migration by Bulgarian workers to Western Europe. He argues that the negative impact on labour markets in host countries is exaggerated, and is in any case far outweighed by the benefits they receive from tax revenues and the skills these workers bring – often to the detriment of Bulgaria itself
Evolving Takagi-Sugeno fuzzy systems from data streams (eTS+).
No full textIt is a well known fact that nowadays we are faced with not only large data sets that we need to process quickly, but with huge data streams (Domingos and Hulten, 2001). Special requirements are also placed by the fast growing sector of autonomous systems where systems that can re-train and adapt ‘on-fly’ are required (Patchett and Sastri, 2007). Similar requirements are enforced by the advanced process industries for self-developing and self-maintaining sensors (Qin et al., 1997). Now they even talk about self-learning industries (EC, 2007). All of these requirements cannot be met by using off-line methods and systems that can only adjust their parameters and/or are linear (Astroem and Wittenmark, 1989). These requirements call for a new type of systems that assumes the structure of non-linear, non-stationary systems to be adaptive and flexible. The author of this chapter started research work in this direction around the turn of the century (Angelov and Buswell, 2001; Angelov, 2002) and this research culminated in proposing with Dr. D. Filev the so called evolving Takagi-Sugeno (eTS) fuzzy system (Angelov and Filev, 2003). Since then a number of improvements of the original algorithm has been done, which require a systematic description in one publication. In this chapter an enhanced version of the eTS algorithm will be described which is called eTS+. It has been tested on a data stream from real engine test bench (data provided courtesy of Dr. E. Lughofer, Linz, Austria). The results demonstrate the superiority of the proposed enhanced approach for modeling real data stream in precision, simplicity and interpretability, and computational resources used. (c) IEEE Press and John Wiley and Son
The performance of Bulgarian food markets during reform
Get PDFFood policy often depends on markets and markets depend on institutions. But how good do institutions have to be before reforms can be launched? Relying on well timed surveys of agricultural prices and a joint study by the Government of Bulgaria and the World Bank on agricultural market institutions, this paper presents evidence that performance in food markets improved following significant policy reforms in Bulgaria, although public institutions remained weak. This suggests that even though strong institutions are preferred to weak ones, it can be costly and impractical to delay policy reforms until work on strengthening institutions is finished. Still, measured performance varied by place and by commodity, suggesting that markets developed at different tempos and that the distribution of benefits from improved markets was uneven. This points to the need to address the costs of adjustment as policies change. The paper introduces a new approach to measure market performance based on composite-error techniques.Markets and Market Access,Transport Economics Policy&Planning,Economic Theory&Research,Access to Markets,Agribusiness
Evolving Intelligent Systems, eIS
Get PDFThe basic concept, formulation, background, and a panoramic view over the recent research results and open problems in the newly emerging area of research that is on the crossroads of computational intelligence and cybernetics is compressed in this short communication. Intelligent systems can be defined as systems that incorporate some form of reasoning that is typical for humans. Fuzzy Systems are well known for being able to formalize the approximate reasoning that still separates humans from machines. Artificial neural networks have proven to be a useful form of parallel processing of information that employs principles from the organization of the brain. Finally, the evolution is a phenomenon that was initially used to solve optimization problems inspired by the so called 'genetic algorithms' due to D. E. Goldberg and 'genetic programming' due to J. Koza. These types of evolutionary algorithms are mimicking the natural selection that takes place in populations of living creatures over generations. More recently, the evolution of individual systems within their life-span (self-organization, learning through experience, and self-developing) has attracted the attention. These systems called 'evolving' came as a result of the research into the development of practical on-line algorithms that work in real-time and are close to the theoretically optimal, analytical solutions, suitable for non-stationary, non-linear problems of modeling, control, prediction, classification, clustering, signal processing. Due to the limited space and the specific purpose of this communication only the basic elements of the concept will be outlined. This concept represents, in fact, a higher level adaptation that concerns model structure as well as model parameters. It can also be considered as an extension of the multi-model concept known from the control theory, and of the on-line identification of fixed structure fuzzy rule-based models. It can also be considered as an extension of the learning neural networks methods in direction of on-line applications with a structure that can grow and shrink. This new concept of 'evolving intelligent systems' can also be treated in the framework of the knowledge and data integration. Evolutionary, population/generation based computation, can be applied to optimize parameters and features of an individual system, that learns incrementally from incoming data. The specific of this paper lays in the generalization of the recent advances in the development of evolving fuzzy and neuro-fuzzy models and the more analytical angle of consideration through the prism of knowledge evolution as opposed to the usually used data-centred approach. This powerful new concept has been recently introduced by the authors in a series of parallel works and is still under intensive development. It forms the conceptual basis for the development of the truly intelligent systems. A number of applications of this technique to a range of industrial and benchmark processes have been recently reported. Due to the lack of space only some of them will be mentioned primarily with illustrative purpose
MODELLING INVOLUNTARY PART-TIME AND FIXED-TERM EMPLOYMENT AMONG YOUNG PEOPLE AND ADULTS IN BULGARIA
Get PDFWith the labour market becoming increasingly flexible, there has been a growing trend towards non-standard models of temporary employment that allow persons who, for some reason, prefer fixed-term or part-time employment to earn income. Hence, some EU member states have been employing policies and measures to facilitate the access to flexible employment at all levels within organizations, including access to vocational training, so as to provide better career growth and professional mobility opportunities. Furthermore, some categories of employees and workers do not enter into similar employment arrangements voluntarily but are forced to do so by a number of factors such as family commitments, age or disability constraints, education and training, the need to relocate, cyclical economic crises, etc. We propose a methodology for studying the voluntary/involuntary character of two major types of flexible employment – part-time and fixedterm employment, from the perspective of employees, employers and the labour market. The focus of attention is on the groups exposed to the highest risk on the national labour market, i.e. young people aged 15-29 and adults aged 55-64
Mass Privatisation Funds: The New Institutional Investors in the East? A Comparative Study of Mass Privatisation Schemes
No full textПламен Дойнов – Поколение и поезия. 1956–1989
Get PDFThe article deals with Plamen Doynovʼs idea of the poetic generations during the time of the socialism. There are the connections between the administrative power and the poets, between the ideological directives and the poetry as an autonomous area. The author suggests the idea of the periodization within poetry during the socialism.The article deals with Plamen Doynovʼs idea of the poetic generations during the time of the socialism. There are the connections between the administrative power and the poets, between the ideological directives and the poetry as an autonomous area. The author suggests the idea of the periodization within poetry during the socialism
Impact of the economic crisis on the national system of industrial relations in Bulgaria: policies as a key instrument for recovery
No full textIdentification of Evolving Rule-based Models.
Get PDFAn approach to identification of evolving fuzzy rule-based (eR) models is proposed. eR models implement a method for the noniterative update of both the rule-base structure and parameters by incremental unsupervised learning. The rule-base evolves by adding more informative rules than those that previously formed the model. In addition, existing rules can be replaced with new rules based on ranking using the informative potential of the data. In this way, the rule-base structure is inherited and updated when new informative data become available, rather than being completely retrained. The adaptive nature of these evolving rule-based models, in combination with the highly transparent and compact form of fuzzy rules, makes them a promising candidate for modeling and control of complex processes, competitive to neural networks. The approach has been tested on a benchmark problem and on an air-conditioning component modeling application using data from an installation serving a real building. The results illustrate the viability and efficiency of the approach. (c) IEEE Transactions on Fuzzy System
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