368 research outputs found

    Soft computing and its use in risk management

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    New analytical methods have begun to be used in risk management. The methods such as fuzzy logic, neural network and genetic algorithms rank among them. The article shortly describes these methods and represents their possible applications in the risk management. These methods can contribute to decreasing of the risk and thus the human and material losses

    Almost log-optimal trading strategies for small transaction costs in model with stochastic coefficients

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    summary:We consider a non-consuming agent investing in a stock and a money market interested in the portfolio market price far in the future. We derive a strategy which is almost log-optimal in the long run in the presence of small proportional transaction costs for the case when the rate of return and the volatility of the stock market price are bounded It o processes with bounded coefficients and when the volatility is bounded away from zero

    Determination of grain size and resistance to corrosion of stainless steel welded pipes

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    Discover problems of welds is not so easy from time to time. Specially, If welding was made in rough environmental conditions such as high temperature, humidity and dusty wind. It is necessary to provide good conditions to realize basic step of welding. For welding, have been used welding procedures specification and procedure qualification record. However, dificult conditions, documentations rightness or human errors are always here. Common weld defects like cracks, porosity, lack of penetration and distortion can compromise the strength of the base metal, as well as the integrity of the weld. According of site inspection, there were suspicion of intercrystalline corrosion, inclusions, leaker or segregation in root of weld, root weld stretches to the pipe inside, the welded pipes are not in axially level, the not proper surface treatment after welding and keep the intervals between single welds to not overheat the pipes.O

    Западная геополитическая ориентация и общественное мнение в пост-коммунистических странах: толкование взглядов

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    The article provides an analysis of different geopolitical and geoeconomic options of postcommunist countries and confronts the character of post-communist regimes with the public opinion on basic geopolitical and geoeconomic orientations of the countries concerned. The post-communist regimes in mid-1990s are assessed in terms of democratisation and economic liberalisation. It is stressed that westward geopolitical and geoeconomic options were much demanding in respect of political and economic reforms and western-style adjustments and adaptations of behaviour of political and economic elites and different groups of citizens. Eastward options were linked up with associations with Russia and Eurasian countries. Statistical analysis concerned with the public opinion in nineteen postcommunist countries indicates the importance of inherited higher economic development level and progress in democratisation for the public support of the westward (i.e. EU) orientation.Autori daju analizu različitih geopolitičkih i geoekonomskih mogućnosti postkomunističkih zemalja te suprotstavljaju karakter postkomunističkih režima javnom mišljenju o osnovnim geopolitičkim i geoekonomskim orijentacijama zemalja o kojima je riječ. Postkomunistički režimi sredinom 1990-ih ocjenjuju se u odnosu na demokratizaciju i liberalizaciju unutarnjih i vanjskih ekonomskih odnosa. Naglašava se da su prozapadne geopolitičke i geoekonomske mogućnosti vrlo zahtjevne što se tiče politički h i gospodarskih reformi te prilagodbe i adaptacije ponašanja političkih i gospodarskih elita i različitih skupina građana na zapadnjački stil. Prozapadne opcije uključuju geopolitičke tranzicije s ciljem potpunog članstva u Europskoj uniji ili manje zahtjevnog oblika integracije kao što su sporazumi o slobodnoj trgovini i političkom partnerstvu. Proistočne geopolitičke opcije povezane su s udruživanjem s Rusijom i istočnoeuropskim zemljama ili s razvojnim strategijama tzv. Azijskih tigrova ili proizvođača nafte. Autori daju statistički model kako bi pokazali mnoge čimbenike koji objašnjavaju razlike u orijentaciji prema integraciji u EU kao što je izraženo 1996. u javnom mišljenju u postkomunističkim zemljama o kojima se govori. Statistička analiza 19 postkomunističkih zemalja pokazuje da je javnost u onim državama, koje su naslijedile višu razinu ekonomskog razvoja, pokazala veći stupanj podrške zapadnoj orijentaciji (tj. prema EU). Napredak demokratizacije osigurao je povoljne uvjete za zapadnu geopolitičku orijentaciju. Intenzivne geoekonomske veze s bivšim trgovačkim blokom kojim je dominirao Sovjetski Savez, znatno je umanjio orijentaciju prema zapadu u javnom mišljenju postkomunističkih zemalja. Analiza pokazuje da se na temeljni razdor (raskol) u zapadnoj i istočnoj orijentaciji sredinom 1990-ih može gledati kao na dugotrajnu geopolitičku i geoekonomsku diferencijaciju kontinenta.В статье дастся анализ различных геополитических и гео-экономических альтернатив будущего развития nост-коммунистических стран; характер пост-коммунистисrеских режимов противопоставлястся общественному мнению относительно геополитической и гео-экономичесoй ориенгпщии соответствующих стран. Пост-коммунистические режимы в середине 1990-х оцениваются с точки зрения демократизации и либерализации внутренних и внешн их экономичeских отношений. Авторы nодчеркивают, что западная геополитическая и гео-экономическая ориентaщия требовательна с точки зрения политических и экономических реформ, присnособления к западному образу жизни и адаптации поведения политических и экономических элит и различных групп граждан. Западная ориентация связанна или с геополитическим переходом, цель которого полноправное членство в Европейском Союзе, или с менее требовательной формой интеграции, как, например, соглашения о свободной торговле и политическое партнерство. Восточная ориентация связывается или с сотрудничеством с Россией и другими евразийскими государствами, или с принятнем стратегий развития так называемых Азиатских тигров или стран-нефтепроизводителей. Авторы вводят статистическую модель, с помощью которой выделяют факторы, объясняющие различия в общественном мнении (1996 г.) в разных пост-коммунистических странах относительно включения в Европейский Союз. Статистический анализ, включивший девятнадцать, пост-коммунистических стран, показал, что в странaх более высокого уровня экономического развития общественное мнение в большей мере пддерживает запдную ориентацию (т. е. ориентацию на включение в ЕС). Лрогресс в демокрaтизации также представляет собой благоприятное условие для западной геополитической ориентaции. Интенсивные гео-экономические связи с бывшим торговым блоком, в котором доминировал Советский Союз, ведут, как свидетельствует общественное мнение, к значительному ослаблению западной ориентации. Анализ показьшает, что основной раскол на западную и восточную ориентацию в середине 1990-х годов можно интерпретировать как долгосрочную геоnолитическую и гео-зкономическую дифференциацию континента

    Comparison of two identification models used in adaptive control of continuous-stirred tank reactor

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    The goal of this paper is to compare two identification methods continuous-time and discrete-time. The continuous-time identification model is more accurate but not very suitable for on-line identification. This disadvantage was overcome with the use of differential filters. On the other hand, discrete-time identification model has is more suitable for identification but less accurate. Compromise can be found in the delta model as a special type of the discrete-time model parameters of which are related to the sampling period. The adaptive approach is based on the choice of the External Linear Model, parameters of which are identified recursively which satisfies the adaptivity of this system. Proposed control strategy was applied on the mathematical model of the Continuous Stirred-Tank reactor as a typical nonlinear lumped-parameters system used in the industry

    Titanium and Stainless Steel MIG LSC Welding

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    This paper deals with the issue of welding two different materials - titanium and stainless steel (UNS N50400 X5CrNi 18-10). These two materials have completely different chemical compositions and mechanical properties; therefore, process of their mutual welding is complicated. Melting temperature of both materials is also different. An innovative MIG LSC arc welding method with an additional material has been selected for this purpose. A protective atmosphere was used order to avoid galvanic corrosion of materials that would preclude the welding process. Aforementioned atmosphere contained 100% Ar. The MIG LSC welding method was designed by Fronius. Presented experiment compares utilization of following 4 different electrodes (additional material) for the welding of titanium and stainless steel: Ti, Fe, corrosion-resistant Fe and CuSi3 electrode. Tensile test was utilized for evaluation of weldment mechanical properties. Measured results were supplemented with a metallographic analysis snapshot and tensile diagram.O

    Западная геополитическая ориентация и общественное мнение в пост-коммунистических странах: толкование взглядов

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    The article provides an analysis of different geopolitical and geoeconomic options of postcommunist countries and confronts the character of post-communist regimes with the public opinion on basic geopolitical and geoeconomic orientations of the countries concerned. The post-communist regimes in mid-1990s are assessed in terms of democratisation and economic liberalisation. It is stressed that westward geopolitical and geoeconomic options were much demanding in respect of political and economic reforms and western-style adjustments and adaptations of behaviour of political and economic elites and different groups of citizens. Eastward options were linked up with associations with Russia and Eurasian countries. Statistical analysis concerned with the public opinion in nineteen postcommunist countries indicates the importance of inherited higher economic development level and progress in democratisation for the public support of the westward (i.e. EU) orientation.Autori daju analizu različitih geopolitičkih i geoekonomskih mogućnosti postkomunističkih zemalja te suprotstavljaju karakter postkomunističkih režima javnom mišljenju o osnovnim geopolitičkim i geoekonomskim orijentacijama zemalja o kojima je riječ. Postkomunistički režimi sredinom 1990-ih ocjenjuju se u odnosu na demokratizaciju i liberalizaciju unutarnjih i vanjskih ekonomskih odnosa. Naglašava se da su prozapadne geopolitičke i geoekonomske mogućnosti vrlo zahtjevne što se tiče politički h i gospodarskih reformi te prilagodbe i adaptacije ponašanja političkih i gospodarskih elita i različitih skupina građana na zapadnjački stil. Prozapadne opcije uključuju geopolitičke tranzicije s ciljem potpunog članstva u Europskoj uniji ili manje zahtjevnog oblika integracije kao što su sporazumi o slobodnoj trgovini i političkom partnerstvu. Proistočne geopolitičke opcije povezane su s udruživanjem s Rusijom i istočnoeuropskim zemljama ili s razvojnim strategijama tzv. Azijskih tigrova ili proizvođača nafte. Autori daju statistički model kako bi pokazali mnoge čimbenike koji objašnjavaju razlike u orijentaciji prema integraciji u EU kao što je izraženo 1996. u javnom mišljenju u postkomunističkim zemljama o kojima se govori. Statistička analiza 19 postkomunističkih zemalja pokazuje da je javnost u onim državama, koje su naslijedile višu razinu ekonomskog razvoja, pokazala veći stupanj podrške zapadnoj orijentaciji (tj. prema EU). Napredak demokratizacije osigurao je povoljne uvjete za zapadnu geopolitičku orijentaciju. Intenzivne geoekonomske veze s bivšim trgovačkim blokom kojim je dominirao Sovjetski Savez, znatno je umanjio orijentaciju prema zapadu u javnom mišljenju postkomunističkih zemalja. Analiza pokazuje da se na temeljni razdor (raskol) u zapadnoj i istočnoj orijentaciji sredinom 1990-ih može gledati kao na dugotrajnu geopolitičku i geoekonomsku diferencijaciju kontinenta.В статье дастся анализ различных геополитических и гео-экономических альтернатив будущего развития nост-коммунистических стран; характер пост-коммунистисrеских режимов противопоставлястся общественному мнению относительно геополитической и гео-экономичесoй ориенгпщии соответствующих стран. Пост-коммунистические режимы в середине 1990-х оцениваются с точки зрения демократизации и либерализации внутренних и внешн их экономичeских отношений. Авторы nодчеркивают, что западная геополитическая и гео-экономическая ориентaщия требовательна с точки зрения политических и экономических реформ, присnособления к западному образу жизни и адаптации поведения политических и экономических элит и различных групп граждан. Западная ориентация связанна или с геополитическим переходом, цель которого полноправное членство в Европейском Союзе, или с менее требовательной формой интеграции, как, например, соглашения о свободной торговле и политическое партнерство. Восточная ориентация связывается или с сотрудничеством с Россией и другими евразийскими государствами, или с принятнем стратегий развития так называемых Азиатских тигров или стран-нефтепроизводителей. Авторы вводят статистическую модель, с помощью которой выделяют факторы, объясняющие различия в общественном мнении (1996 г.) в разных пост-коммунистических странах относительно включения в Европейский Союз. Статистический анализ, включивший девятнадцать, пост-коммунистических стран, показал, что в странaх более высокого уровня экономического развития общественное мнение в большей мере пддерживает запдную ориентацию (т. е. ориентацию на включение в ЕС). Лрогресс в демокрaтизации также представляет собой благоприятное условие для западной геополитической ориентaции. Интенсивные гео-экономические связи с бывшим торговым блоком, в котором доминировал Советский Союз, ведут, как свидетельствует общественное мнение, к значительному ослаблению западной ориентации. Анализ показьшает, что основной раскол на западную и восточную ориентацию в середине 1990-х годов можно интерпретировать как долгосрочную геоnолитическую и гео-зкономическую дифференциацию континента

    Self-tuning control: Laboratory real-time education

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    The combination of the automatic control theory courses and practical implementation of the designed controller algorithms in real-time conditions is very important for training of the control engineers. This contribution presents a MATLAB-Toolbox for design, simulation verification and especially real-time implementation of single input - single output (SISO) discrete self-tuning controllers. The proposed adaptive controllers what are included into a Toolbox can be divided into three groups. The first group covers PID adaptive algorithms using traditional Ziegler-Nichols method for the setting of the controller parameters, the second group of described controllers is based on the pole placement design and the third group contains the controllers derived on the other approaches (dead-beat, minimum variance etc.). The controllers are implemented as an encapsulated SIMULINK blocks and thus allows users simple integration into existing SIMULINK schemas. The process of developing real-time applications using MATLAB Real-Time Workshop and several control courses is also presented. The MATLAB-Toolbox is very successfully used in Adaptive Control Course in education practice for design and verification of self-tuning control systems in real-time. It is suitable for design and verification of the industrial controllers, too. The MATLAB-Toolbox is available free ofcharge at Internet site - bttp:llwww.utb.cz/stctooll. Copyright © IFAC Advances in Control Education Oulu, Finland, 200
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