8 research outputs found

    Proposal of a complementary method of data compression by discrete event methodology applied at a low level of abstraction

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    Orientadores: Edson Moschim, Yuzo IanoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: O presente trabalho implementa um modelo baseado em eventos discretos aplicados em um baixo nível de abstração em um sistema de telecomunicações chamado método híbrido, sendo usado o ambiente de simulação Simulink® do software Matlab®. Com o objetivo de melhorar a transmissão da informação em sistemas de telecomunicações e contribuir para a área de estudo, em ambiente de simulação é proposto um processo de pré-codificação de bits baseada na aplicação de eventos discretos no sinal antes do processo de modulação. A proposta traz uma abordagem diferente do que se é usualmente feito, na qual a transmissão de sinal no canal é realizada no domínio discreto com a implementação de entidades discretas no processo de geração de bits, tendo como ênfase o bit zero. Na simulação são considerados formatos de modulação avançada para transmissão de sinal em um canal AWGN. Os resultados mostram melhorias na utilização da memória e no desempenho computacional, sendo de 9 a 34%, assim como também ao tempo de simulação. Sendo assim, a extensão desses resultados, tem um forte impacto no melhoramento de métodos realizados em camadas mais altas, já que a proposta atua na camada físicaAbstract: The present work implements a model based on discrete events applied at a low level of abstraction in a telecommunication system named hybrid method, being used the Simulink® simulation environment of the Matlab® software. With the objective of improving the transmission of information in telecommunication systems and contribute to the study area, in simulation environment is proposed a pre-coding process of bits based in the application of discrete events in the signal before of the modulation process. The proposal brings a different approach of usual technical, in which the signal transmission on the channel is realized in the discrete domain with the implementation of discrete entities in the process of bit generation having as emphasis the zero bit. In the simulation are considered advanced modulation formats for signal transmission in an AWGN channel. The results show improvements in memory utilization and computational performance, from 9 to 34%, as well as simulation time. Thus, the extension of these results has a strong impact on the improvement of methods performed in higher layers, since the proposal acts on the physical layerMestradoEletrônica, Microeletrônica e OptoeletrônicaMestre em Engenharia Elétrica132495/2016-3CNP

    Bioinspired metaheuristic algorithms for global optimization

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    This paper presents concise comparison study of newly developed bioinspired algorithms for global optimization problems. Three different metaheuristic techniques, namely Accelerated Particle Swarm Optimization (APSO), Firefly Algorithm (FA), and Grey Wolf Optimizer (GWO) are investigated and implemented in Matlab environment. These methods are compared on four unimodal and multimodal nonlinear functions in order to find global optimum values. Computational results indicate that GWO outperforms other intelligent techniques, and that all aforementioned algorithms can be successfully used for optimization of continuous functions

    Experimental Evaluation of Growing and Pruning Hyper Basis Function Neural Networks Trained with Extended Information Filter

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    In this paper we test Extended Information Filter (EIF) for sequential training of Hyper Basis Function Neural Networks with growing and pruning ability (HBF-GP). The HBF neuron allows different scaling of input dimensions to provide better generalization property when dealing with complex nonlinear problems in engineering practice. The main intuition behind HBF is in generalization of Gaussian type of neuron that applies Mahalanobis-like distance as a distance metrics between input training sample and prototype vector. We exploit concept of neuron’s significance and allow growing and pruning of HBF neurons during sequential learning process. From engineer’s perspective, EIF is attractive for training of neural networks because it allows a designer to have scarce initial knowledge of the system/problem. Extensive experimental study shows that HBF neural network trained with EIF achieves same prediction error and compactness of network topology when compared to EKF, but without the need to know initial state uncertainty, which is its main advantage over EKF

    Integrationsaspekte der Simulation: Technik, Orgnisation und Personal, Karlsruhe, 7. und 8. Oktober 2010 = Integration Aspects of Simulation: Equipment, Organization and Personnell, Karlsruhe, 7th and 8th October 2010

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    Die Integration technischer, organisatorischer und personalorientierter Aspekte in Simulationsverfahren ist das Leitthema der 14. Fachtagung der Arbeitsgemeinschaft Simulation (ASIM) innerhalb der Gesellschaft für Informatik, die vom Institut für Arbeitswissenschaft und Betriebsorganisation im Oktober 2010 ausgerichtet wurde. Der vorliegende Tagungsband gibt somit einen vertiefenden Einblick in neue Entwicklungen und Beispiele guter Praxis der Simulation über den deutschsprachigen Raum hinaus

    Biomass for Energy Country Specific Show Case Studies

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    In many domestic and industrial processes, vast percentages of primary energy are produced by the combustion of fossil fuels. Apart from diminishing the source of fossil fuels and the increasing risk of higher costs and energy security, the impact on the environment is worsening continually. Renewables are becoming very popular, but are, at present, more expensive than fossil fuels, especially photovoltaics and hydropower. Biomass is one of the most established and common sources of fuel known to mankind, and has been in continuous use for domestic heating and cooking over the years, especially in poorer communities. The use of biomass to produce electricity is interesting and is gaining ground. There are several ways to produce electricity from biomass. Steam and gas turbine technology is well established but requires temperatures in excess of 250 °C to work effectively. The organic Rankine cycle (ORC), where low-boiling-point organic solutions can be used to tailor the appropriate solution, is particularly successful for relatively low temperature heat sources, such as waste heat from coal, gas and biomass burners. Other relatively recent technologies have become more visible, such as the Stirling engine and thermo-electric generators are particularly useful for small power production. However, the uptake of renewables in general, and biomass in particular, is still considered somewhat risky due to the lack of best practice examples to demonstrate how efficient the technology is today. Hence, the call for this Special Issue, focusing on country files, so that different nations’ experiences can be shared and best practices can be published, is warranted. This is realistic, as it seems that some nations have different attitudes to biomass, perhaps due to resource availability, or the technology needed to utilize biomass. Therefore, I suggest that we go forward with this theme, and encourage scientists and engineers who are researching in this field to present case studies related to different countries. I certainly have one case study for the UK to present
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