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An approach to neuro-fuzzy feedback control in statistical process controlWang, Liren January 2001 (has links)
It is a difficult challenge to develop a feedback control system for Statistical Process Control (SPC) because there is no effective method that can be used to calculate the accurate magnitude of feedback control actions in traditional SPC. Suitable feedback adjustments are generated from the experiences of process engineers. This drawback means that the SPC technique can not be directly applied in an automatic system. This thesis is concerned with Fuzzy Sets and Fuzzy Logic applied to the uncertainty of relationships between the SPC (early stage) alarms and SPC implementation. Based on a number of experiments of the frequency distribution for shifts of abnormal process averages and human subjective decision, a Fuzzy-SPC control system is developed to generate the magnitude of feedback control actions using fuzzy inference. A simulation study which is written in C++ is designed to implement a Fuzzy-SPC controller with satisfactory results. To further reduce the control errors, a NeuroFuzzy network is employed to build NNFuzzy- SPC system in MATLAB. The advantage of the leaning capability of Neural Networks is used to optimise the parameters of the Fuzzy- X and Fuzzy-J? controllers in order to obtain the ideal consequent membership functions to adapt to the randomness of various processes. Simulation results show that the NN-Fuzzy-SPC control system has high control accuracy and stable repeatability. To further improve the practicability of a NN-Fuzzy-SPC system, a combined forecaster with EWMA chart and digital filter is designed to reduce the NN-Fuzzy-SPC control delay. For the EWMA chart, the smoothing constant 0 is investigated by a number of experiments and optimised in the forecast process. The Finite Impulse Response (FIR) lowpass filter is designed to smooth the input data (signal) fluctuations in order to reduce the forecast errors. An improved NN-Fuzzy-SPC control system which shows high control accuracy and short control delay can be applied in both automatic control and online quality control.
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Aplicação da Lógica Fuzzy para avaliação do faturamento do consumo de energia elétrica e demanda de uma empresa de avicultura de posturaGabriel, Camila Pires Cremasco [UNESP] 02 July 2008 (has links) (PDF)
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gabriel_cpc_dr_botfca.pdf: 833335 bytes, checksum: 4475ce35625358eeb8afee9bf905ce59 (MD5) / A região de Bastos-SP é responsável por grande parte da produção brasileira de ovos. Muitas granjas nesta região produzem a própria ração para alimentação de suas aves através da trituração de milho e soja com motores elétricos muitas vezes super-dimensionados, trabalhando em vazio ou em horário de pico. Esta atividade é responsável por grande parte do gasto energético da empresa. Existem dois fatores que avaliam o modo de utilização desta energia, denominados fator de potência ( fp) e fator de carga ( fc), que indicam a eficiência e racionalidade da forma de utilização da energia elétrica, respectivamente. A necessidade de uma avaliação global da utilização da energia, levando em consideração os dois fatores citados, é realizada por especialistas da área energética para a determinação da situação real da empresa. A lógica fuzzy estabelece a criação de algoritmos genéticos, que são capazes de imitar parte do raciocínio humano. Esta lógica aproxima métodos computacionais e o raciocínio humano, o que possibilita a avaliação global da empresa por métodos computacionais e não mais de especialistas da área energética. Estes métodos são sintetizados criando-se um programa computacional baseado em regras criadas a partir desta lógica, que denominamos controlador fuzzy.O presente trabalho preocupou-se em criar um controlador fuzzy para a avaliação do faturamento do consumo de energia elétrica e demanda de potência ativa e reativa em uma empresa de avicultura de postura. Para isto, coletaram-se dados sobre o comportamento dos parâmetros elétricos, tais como: fator de potência, fator de carga, demanda e consumo ativo. A criação de um controlador fuzzy necessita de um processador de entrada, um conjunto de regras lingüísticas, um método de inferência fuzzy e um processador de saída, gerando um número real como saída... / The region of Bastos-SP is responsible for great part of the Brazilian egg production. Many farms in this region produce the proper ration for feeding of its birds through the triturate of maize and soy with electric engines many large sized times, working in emptiness or schedule of peak. This activity is responsible for great part of the energy expense of the company. Two factors exist that evaluate the way of use of this energy, called power factor ( fp) and load factor ( fc), that indicates the efficiency and rationality of the form of use of the electric energy, respectively. The necessity of a global evaluation of the use of the energy, leading in consideration the two cited factors, is carried through by specialists of the energy area for the determination of the real situation of the company. The logic fuzzy establishes the creation of genetic algorithms, that are capable to imitate part of the human reasoning. This logic approaches computational methods and the human reasoning, what it not more than makes possible the global evaluation of the company for computational methods and specialists of the energy area. These methods are synthecized creating a based computational program in rules created from this logic, that we call controller fuzzy.The present work was worried in creating a controller fuzzy for the evaluation of the invoicing of the consumption of electric energy and demand of active and reactive power in a company of position poultry keeping. For this, they had been collected given on the behavior of the electric parameters, such as: factor of power, load factor, demand and active consumption. The creation of a controller fuzzy needs an entrance processor, a set of linguistic rules, a method of inference fuzzy and a processor of exit, generating a real number as exit. Defining the entrance 0 variable as the load and power factor,... (Complete abstract click electronic access below)
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Aplicação da Lógica Fuzzy para avaliação do faturamento do consumo de energia elétrica e demanda de uma empresa de avicultura de postura /Gabriel, Camila Pires Cremasco, 1978- January 2008 (has links)
Orientador: Angelo Cataneo / Banca: Helenice de Oliveira Florentino Silva / Banca: Ivam Resina / Banca: Flávio Ferrari Aragon / Banca: Fernando Natal de Pretto / Resumo: A região de Bastos-SP é responsável por grande parte da produção brasileira de ovos. Muitas granjas nesta região produzem a própria ração para alimentação de suas aves através da trituração de milho e soja com motores elétricos muitas vezes super-dimensionados, trabalhando em vazio ou em horário de pico. Esta atividade é responsável por grande parte do gasto energético da empresa. Existem dois fatores que avaliam o modo de utilização desta energia, denominados fator de potência ( fp) e fator de carga ( fc), que indicam a eficiência e racionalidade da forma de utilização da energia elétrica, respectivamente. A necessidade de uma avaliação global da utilização da energia, levando em consideração os dois fatores citados, é realizada por especialistas da área energética para a determinação da situação real da empresa. A lógica fuzzy estabelece a criação de algoritmos genéticos, que são capazes de imitar parte do raciocínio humano. Esta lógica aproxima métodos computacionais e o raciocínio humano, o que possibilita a avaliação global da empresa por métodos computacionais e não mais de especialistas da área energética. Estes métodos são sintetizados criando-se um programa computacional baseado em regras criadas a partir desta lógica, que denominamos controlador fuzzy.O presente trabalho preocupou-se em criar um controlador fuzzy para a avaliação do faturamento do consumo de energia elétrica e demanda de potência ativa e reativa em uma empresa de avicultura de postura. Para isto, coletaram-se dados sobre o comportamento dos parâmetros elétricos, tais como: fator de potência, fator de carga, demanda e consumo ativo. A criação de um controlador fuzzy necessita de um processador de entrada, um conjunto de regras lingüísticas, um método de inferência fuzzy e um processador de saída, gerando um número real como saída... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The region of Bastos-SP is responsible for great part of the Brazilian egg production. Many farms in this region produce the proper ration for feeding of its birds through the triturate of maize and soy with electric engines many large sized times, working in emptiness or schedule of peak. This activity is responsible for great part of the energy expense of the company. Two factors exist that evaluate the way of use of this energy, called power factor ( fp) and load factor ( fc), that indicates the efficiency and rationality of the form of use of the electric energy, respectively. The necessity of a global evaluation of the use of the energy, leading in consideration the two cited factors, is carried through by specialists of the energy area for the determination of the real situation of the company. The logic fuzzy establishes the creation of genetic algorithms, that are capable to imitate part of the human reasoning. This logic approaches computational methods and the human reasoning, what it not more than makes possible the global evaluation of the company for computational methods and specialists of the energy area. These methods are synthecized creating a based computational program in rules created from this logic, that we call controller fuzzy.The present work was worried in creating a controller fuzzy for the evaluation of the invoicing of the consumption of electric energy and demand of active and reactive power in a company of position poultry keeping. For this, they had been collected given on the behavior of the electric parameters, such as: factor of power, load factor, demand and active consumption. The creation of a controller fuzzy needs an entrance processor, a set of linguistic rules, a method of inference fuzzy and a processor of exit, generating a real number as exit. Defining the entrance 0 variable as the load and power factor,... (Complete abstract click electronic access below) / Doutor
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Vývojové prostředí pro umělou inteligenci Modul fuzzy čísel / Integrated development environment for Artificial Intelligence Fuzzy Numbers ModulePergl, Miroslav January 2009 (has links)
Master’s thesis deals with mathematical operation with fuzzy numbers. The first part of the thesis deals with theoretical knowledge of fuzzy arithmetic and defines fuzzy sets, fuzzy numbers, universum and five membership function used in program. In the concrete it describes – cut method for dealing with fuzzy numbers as with limited interval for specific level which simplifies computation. The second part of the thesis contains description of programmed module for mathematical operation with fuzzy numbers. There is described creation of user interface which is using to set parameters of computation. There are also described support functions which make operation with fuzzy numbers possible and operation ensures output.
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Fuzzy GUHA / Fuzzy GUHARalbovský, Martin January 2006 (has links)
The GUHA method is one of the oldest methods of exploratory data analysis, which is regarded as part of the data mining or knowledge discovery in databases (KDD) scienti_c area. Unlike many other methods of data mining, the GUHA method has firm theoretical foundations in logic and statistics. In scope of the method, finding interesting knowledge corresponds to finding special formulas in satisfactory rich logical calculus, which is called observational calculus. The main topic of the thesis is application of the "fuzzy paradigm" to the GUHA method By the term "fuzzy paradigm" we mean approaches that use many-valued membership degrees or truth values, namely fuzzy set theory and fuzzy logic. The thesis does not aim to cover all the aspects of this application, it emphasises mainly on: - Association rules as the most prevalent type of formulas mined by the GUHA method - Usage of fuzzy data - Logical aspects of fuzzy association rules mining - Comparison of the GUHA theory to the mainstream fuzzy association rules - Implementation of the theory using the bit string approach The thesis throughoutly elaborates the theory of fuzzy association rules, both using the theoretical apparatus of fuzzy set theory and fuzzy logic. Fuzzy set theory is used mainly to compare the GUHA method to existing mainstream approaches to formalize fuzzy association rules, which were studied in detail. Fuzzy logic is used to define novel class of logical calculi called logical calculi of fuzzy association rules (LCFAR) for logical representation of fuzzy association rules. The problem of existence of deduction rules in LCFAR is dealt in depth. Suitable part of the proposed theory is implemented in the Ferda system using the bit string approach. In the approach, characteristics of examined objects are represented as strings of bits, which in the crisp case enables efficient computation. In order to maintain this feature also in the fuzzy case, a profound low level testing of data structures and algoritms for fuzzy bit strings have been carried out as a part of the thesis.
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Supervisory control and power management of an AC microgridAl Badwawi, Rashid Said Mohammed January 2017 (has links)
The thesis examines the design and implementation of a supervisory controller for the energy management of an AC stand-alone microgrid. The microgrid under study consists of a photovoltaic (PV), battery energy storage system (BESS) and auxiliary (micro gas turbine) units connected to a common AC bus and supplies a local load. The BESS unit has to maintain the AC bus voltage and frequency and needs to balance the difference between the intermittent PV power and that consumed by the load. However, the BESS has limited energy capacity and power rating and therefore it is important to implement a supervisory controller that can curtail the PV power to prevent the battery from being overcharged and also to operate the auxiliary unit to prevent the battery from being over discharged. A Fuzzy Logic Controller (FLC) that can be implemented inside the BESS unit is proposed. It monitors the battery power and State of Charge (SOC) and varies the bus frequency accordingly. The variation in the bus frequency serves as a communication means to the PV and auxiliary units. If the frequency is increased above the nominal value, the PV unit starts to curtail its power and if the frequency is decreased, the auxiliary unit starts to generate power. Power curtailment and supplement are proportional to the frequency variation. In order to avoid any need for communication links between the units, the DC/AC inverters of all the units adopt the well-known wireless droop technique. The droop control of the auxiliary unit is implemented in such a way that the unit is floating on the bus and thus it generates power only if the bus frequency is decreased below its nominal value. The main merits of the proposed controller are simplicity and easiness of implementation inside the BESS unit. The effectiveness of the controller in protecting the battery from over-charging/over-discharging has been verified by simulations including a real-time simulation and experimentally. Furthermore, the thesis investigates the effect of sudden shading of a PV and concentrated PV (CPV) on the bus frequency of an AC stand-alone microgrid. It is known that the CPV power can drop drastically, compared to traditional PV, when it is exposed to shading. A simulation model of the CPV in a microgrid has been built and the results are compared to those of the traditional PV. It is found that shading of the CPV has much more stronger effect on the bus frequency.
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Fuzzy Unequal Clustering In Wireless Sensor NetworksBagci, Hakan 01 January 2010 (has links) (PDF)
In order to gather information more efficiently, wireless sensor networks are partitioned into clusters. The most of the proposed clustering algorithms do not consider the location of the base station. This situation causes hot spots problem in multi-hop wireless sensor networks. Unequal clustering mechanisms, which are designed by considering the base station location, solve this problem. In this thesis, we propose a fuzzy unequal clustering algorithm (EAUCF) which aims to prolong the lifetime of wireless sensor networks. EAUCF adjusts the cluster-head radius considering the residual energy and the distance to the base station parameters of the sensor nodes. This helps decreasing the intra-cluster work of the sensor nodes which are closer to the base station or have lower battery level. We utilize fuzzy logic for handling the uncertainties in cluster-head radius estimation. We compare our algorithm with some popular algorithms in literature, namely LEACH, CHEF and EEUC, according to First Node Dies (FND), Half of the Nodes Alive (HNA) and energy-efficiency metrics. Our simulation results show that EAUCF performs better than other algorithms in most of the cases considering FND, HNA and energy-efficiency. Therefore, our proposed algorithm is a stable and energy-efficient clustering algorithm.
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An intelligent hybrid model for customer requirements interpretation and product design targets determinationFung, Ying-Kit (Richard) January 1997 (has links)
The transition of emphasis in business competition from a technology-led age to a market-oriented era has led to a rapid shift from the conventional "economy of scale" towards the "economy of scope" in contemporary manufacturing. Hence, it is necessary and essential to be able to respond to the dynamic market and customer requirements systematically and consistently. The central theme of this research is to rationalise and improve the conventional means of analysing and interpreting the linguistic and often imprecise customer requirements in order to identify the essential product features and determine their appropriate design targets dynamically and quantitatively through a series of well proven methodologies and techniques. The major objectives of this research are: a) To put forward a hybrid approach for decoding and processing the Voice of Customer (VoC) in order to interpret the specific customer requirements and market demands into definitive product design features, and b) To quantify the essential product design features with the appropriate technical target values for facilitating the downstream planning and control activities in delivering the products or services. These objectives would be accomplished through activities as follows: • Investigating and understanding the fundamental nature and variability of customer attributes (requirements); • Surveying and evaluating the contemporary approaches in handling customer attributes; • Proposing an original and generic hybrid model for categorising, prioritising and interpreting specific customer attributes into the relevant product attributes with tangible target values; • Developing a software system to facilitate the implementation of the proposed model; • Demonstrating the functions of the hybrid model through a practical case study. This research programme begins with a thorough overview of the roles, the changing emphasis and the dynamic characteristics of the contemporary customer demand with a view to gaining a better understanding on the fundamental nature and variability of customer attributes. It is followed by a review of a number of well proven tools and techniques including QFD, HoQ, Affinity Diagram and AHP etc. on their applicability and effectiveness in organising, analysing and responding to dynamic customer requirements. Finally, an intelligent hybrid model amalgamating a variety of these techniques and a fuzzy inference sub-system is proposed to handle the diverse, ever-changing and often imprecise VoC. The proposed hybrid model is subsequently demonstrated in a practical case study.
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Vigilância sanitária em serviços de saúde: risco e proteção da saúde em serviços de hemodiálise.Leite, Handerson Jorge Dourado January 2007 (has links)
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Previous issue date: 2007 / As dificuldades da vigilância sanitária em lidar com a complexidade presente nos serviços de saúde parecem estar associadas à falta de instrumentos adequados para alicerçar suas práticas. Um caso que parece exemplificar os serviços de saúde na atualidade são os serviços de diálise que possuem uma grande quantidade de tecnologia agregada em maquinários e procedimentos. Com o objetivo de analisar, sob a ótica da vigilância sanitária, os riscos existentes nos serviços de hemodiálise, no estado da Bahia, entre 2000 e 2005, conformou-se um estudo de casos múltiplos, descritivo e aplicado, definindo-se a modalidade hemodiálise como objeto de pesquisa por representar a maioria dos tratamentos dialíticos realizados no Brasil. Foi utilizada uma abordagem qualitativa e quantitativa, utilizando-se como técnicas para a operacionalização do estudo a observação direta, a análise documental e a modelagem. O desenvolvimento do estudo proposto foi realizado através da construção de três artigos que se complementam em função do problema em foco. O primeiro teve por objetivo propor uma organização das ações de vigilância sanitária e identificar aportes teóricos para o desenvolvimento de instrumentos que facilitem a apreensão da realidade em serviços de saúde. O segundo desenvolveu um modelo sistêmico, utilizando lógica fuzzy, capaz de gerar um indicador de risco potencial do processo e indicadores de controle sanitário hierarquizados por elementos do processo e atividades do procedimento de hemodiálise. Finalmente, o terceiro artigo analisa os riscos existentes em quatro serviços de hemodiálise na Bahia, entre 2000 a 2005, utilizando o sistema lógico fuzzy desenvolvido e comparando os resultados encontrados com os relatórios de inspeção sanitária existentes nos arquivos do órgão estadual de vigilância sanitária. Os resultados apresentados sugerem a pertinência do uso do sistema lógico fuzzy e uma tendência na redução nos riscos, a partir de 2003, na maioria dos serviços estudados. / Salvador
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Aplikace fuzzy logiky pro hodnocení kvality zákazníků / The Application of Fuzzy Logic for Evaluation of Quality of CustomersŠulc, Ondřej January 2016 (has links)
This master thesis deals with the application of fuzzy logic for evaluating the quality of customers in company PPL CZ s.r.o. For evaluation was used Microsoft Excel and MathWorks MATLAB. There are going to be created models using fuzzy logic. The introductory part is devoted to the theoretical bases that are necessary to understand the whole issue. The second part includes information about the company and analyzes of the current situation. Finally, the last part presents fuzzy models used to evaluation of existing customers.
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