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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Topologically generated fuzzy topological spaces

Schramm, Michael Dwight 01 April 2002 (has links)
No description available.
322

Fuzzy databáze založená na E-R schématu / Fuzzy database based on an E-R schema

Plachý, Milan January 2012 (has links)
This text is especialy intended to those who are interested into fuzzy logic and its application in relational databases. It is mainly focused on concept of fuzzyfied relational database and implementation of such database. This text consists of two parts: theoretical aspects of fuzzyfication and implementation part. Selected extension is based on fuzzy E-R model so the requirements of the real world can be better met. This paper also describes existing solutions on different level of fuzzyfication. Part of the work is design and implementation of a simple software for querying over fuzzyfied relational database. This work shoud also serve as a guide for design and implementation of fuzzy database.
323

A forecasting of indices and corresponding investment decision making application

Patel, Pretesh Bhoola 01 March 2007 (has links)
Student Number : 9702018F - MSc(Eng) Dissertation - School of Electrical and Information Engineering - Faculty of Engineering and the Built Environment / Due to the volatile nature of the world economies, investing is crucial in ensuring an individual is prepared for future financial necessities. This research proposes an application, which employs computational intelligent methods that could assist investors in making financial decisions. This system consists of 2 components. The Forecasting Component (FC) is employed to predict the closing index price performance. Based on these predictions, the Stock Quantity Selection Component (SQSC) recommends the investor to purchase stocks, hold the current investment position or sell stocks in possession. The development of the FC module involved the creation of Multi-Layer Perceptron (MLP) as well as Radial Basis Function (RBF) neural network classifiers. TCategorizes that these networks classify are based on a profitable trading strategy that outperforms the long-term “Buy and hold” trading strategy. The Dow Jones Industrial Average, Johannesburg Stock Exchange (JSE) All Share, Nasdaq 100 and the Nikkei 225 Stock Average indices are considered. TIt has been determined that the MLP neural network architecture is particularly suited in the prediction of closing index price performance. Accuracies of 72%, 68%, 69% and 64% were obtained for the prediction of closing price performance of the Dow Jones Industrial Average, JSE All Share, Nasdaq 100 and Nikkei 225 Stock Average indices, respectively. TThree designs of the Stock Quantity Selection Component were implemented and compared in terms of their complexity as well as scalability. TComplexity is defined as the number of classifiers employed by the design. Scalability is defined as the ability of the design to accommodate the classification of additional investment recommendations. TDesigns that utilized 1, 4 and 16 classifiers, respectively, were developed. These designs were implemented using MLP neural networks, RBF neural networks, Fuzzy Inference Systems as well as Adaptive Neuro-Fuzzy Inference Systems. The design that employed 4 classifiers achieved low complexity and high scalability. As a result, this design is most appropriate for the application of concern. It has also been determined that the neural network architecture as well as the Fuzzy Inference System implementation of this design performed equally well.
324

Uma aplicação da lógica Fuzzy /

Dias, Cristina Helena Bovo Batista. January 2010 (has links)
Orientador: Henrique Lazari / Banca: Adilson José Vieira Brandão / Banca: Wlademir Seixas / Resumo: Desde cedo entramos em contato com as implicações lógicas. O binômio verdadeiro-falso está sempre presente em nossas vidas e nós nos acostumamos a aceitar que as coisas ou são verdadeiras ou são falsas. Divertimo-nos quando alguém nos conta histórias interessantes envolvendo lógica e que terminam em contradições, tais como, por exemplo, a do barbeiro que pode e não pode barbear a si mesmo, ou como a do advogado que consegue ganhar ou perder a mesma causa. Apreciamos mais "paradoxos" sem nos apercebermos que por trás deles existe toda uma teoria matemática, a chamada lógica fuzzy. Essa dissertação tem por objetivo apresentar um resumo deste teoria, mostrando como ela trata a existência de tais paradoxos e dar detalhes sobre uma visão compacta dos conjuntos fuzzy, a saber, utilizando uma representação geométrica. A análise de alguns resultados sobre tais conjuntos usando esta representação leva a uma justificativa para o estudo da lógica fuzzy, a saber, a diferença entre "fuzziness" e probabilidade, incluindo uma demonstração de que "fuzziness", de fato, existe / Abstract: Early on we got in touch with the logical implications. The binomial true-false is always present in our lives and we have come to accept that things are either true or false. Have fun when somebody tells interesting stories involving logic and ending with contradictions, such as, for example, the barber who can and can not shave himself, or as the lawyer who can win or lose the same cause. Appreciate more "paradoxes" without realizing that behind them there is a whole mathematical theory, called fuzzy logic. This thesis aims to present a summary of this theory, showing how it treats the existence of such paradoxes and give details about a compact view of fuzzy sets, namely, using a geometrical representation. The analysis of some results on such sets using this representation leads to a justification for the study of fuzzy logic, namely the difference between "fuzziness" and probability, including a demonstration that "fuzziness" in fact, exists / Mestre
325

Modelagem fuzzy para fixação de trajetórias em sistemas caóticos. / Fuzzy modelling for trajectory fixation in chaotic systems.

Garms, Marco Antonio 16 August 2007 (has links)
Neste trabalho foi realizado um mapeamento de ferramentas analíticas para representação e tratamento computacional de Sistemas Fuzzy. Este mapeamento evidenciou a existência de relações e a adequação do uso da Teoria Fuzzy na construção de modelos para a solução de problemas envolvendo Sistemas Dinâmicos e, em particular, de Sistemas Dinâmicos Caóticos. Propôs-se uma diferenciação entre dois tipos de Sistemas Dinâmicos Fuzzy (SDF\'s) - os Sistemas Dinâmicos Fuzzy Intrínsecos (SDFI\'s) e os Sistemas Dinâmicos Fuzzy Extrínsecos (SDFE\'s). Foram utilizados SDFE\'s na modelagem Fuzzy para a solução de problemas de fixação de trajetórias em sistemas caóticos. Foram desenvolvidos Estudos de Caso que permitiram verificar, por meio de simulações em bilhares e testes em circuito de Chua (este último implementado em protótipo físico) a adequação do uso desta técnica na solução destes problemas. No desenvolvimento da Tese foram obtidas as seguintes realizações relacionadas ao circuito de Chua (CCH): Tratamento computacional sobre circuito real; Utilização de um conversor analógico-digital de oito bits seguido por filtro passa-baixas para compensar a baixa resolução na leitura dos sinais; Utilização de circuito girador para implementar o indutor do CCH; Proposta e realização de um circuito inédito para definir o resistor de controle, via porta paralela do PC, de modo simples e de fácil reprodução. Com relação aos bilhares foram obtidas as seguintes realizações: Definição de um novo tipo de bilhar (Bilhar Newtoniano de Garms & Andrade); Desenvolvimento da análise detalhada das equações de simulação dos bilhares empregados nos Estudos de Caso. Ao rediscutir-se a Lógica Seqüencial Fuzzy definiu-se e desenvolveu-se, por meio da aplicação de realimentação em Circuitos Seqüenciais Fuzzy nos Sistemas Dinâmicos, um Astável Fuzzy (oscilações não-periódicas), o qual exemplifica um SDFI. Finalmente realizaram-se algumas interpretações da Física pela Teoria Fuzzy, utilizando-se o conceito de SDFI\'s. / A mapping of analytical tools for representation and computational treatment of Fuzzy Systems was made in this thesis. This mapping evidenced the existence of relations and the adequacy of the use of the Fuzzy Theory in the models construction for the problems solution involving dynamic systems e, in particular, of chaotic systems. A differentiation was considered about two types of Fuzzy Dynamic Systems - the Intrinsic Fuzzy Dynamic Systems (IFDS) and the Extrinsic Fuzzy Dynamic Systems (EFDS). The EFDS in the Fuzzy modeling is used for the problems solution of trajectories setting in chaotic systems. Case Studies had been developed that allow to verify, by means of simulation in billiards and tests in circuit of Chua (implemented in physical prototype), the adequacy of the use of this strategy in the solution of these problems. Related with Chua circuit, can be mentioned the following achievements: Computational treatment on real circuit; Use of a 8-bits AD converter followed by lowpass filter to compensate this low resolution signals reading; Use of gyrator circuit to implement the inductor used in this circuit; Proposal and accomplishment of a circuit to define the control resistor, via PC parallel port, of simple reproduction. Related with billiards, the following achievements are mentioned: Definition of a new billiard - Garms & Andrade Newtonian Billiard; Development of detailed equations of the simulations billiards analysis. When discussing again the Sequential Logic Fuzzy, is defined and developed, by means of the application of feedback in Sequential Circuits Fuzzy in the Dynamic Systems, an Astable Fuzzy (non-periodic oscillations), which exemplifies an IFDS. Finally, some interpretations of the Physics for the Fuzzy Theory are also presented with the use of the IFDS concept.
326

Modelagem fuzzy para fixação de trajetórias em sistemas caóticos. / Fuzzy modelling for trajectory fixation in chaotic systems.

Marco Antonio Garms 16 August 2007 (has links)
Neste trabalho foi realizado um mapeamento de ferramentas analíticas para representação e tratamento computacional de Sistemas Fuzzy. Este mapeamento evidenciou a existência de relações e a adequação do uso da Teoria Fuzzy na construção de modelos para a solução de problemas envolvendo Sistemas Dinâmicos e, em particular, de Sistemas Dinâmicos Caóticos. Propôs-se uma diferenciação entre dois tipos de Sistemas Dinâmicos Fuzzy (SDF\'s) - os Sistemas Dinâmicos Fuzzy Intrínsecos (SDFI\'s) e os Sistemas Dinâmicos Fuzzy Extrínsecos (SDFE\'s). Foram utilizados SDFE\'s na modelagem Fuzzy para a solução de problemas de fixação de trajetórias em sistemas caóticos. Foram desenvolvidos Estudos de Caso que permitiram verificar, por meio de simulações em bilhares e testes em circuito de Chua (este último implementado em protótipo físico) a adequação do uso desta técnica na solução destes problemas. No desenvolvimento da Tese foram obtidas as seguintes realizações relacionadas ao circuito de Chua (CCH): Tratamento computacional sobre circuito real; Utilização de um conversor analógico-digital de oito bits seguido por filtro passa-baixas para compensar a baixa resolução na leitura dos sinais; Utilização de circuito girador para implementar o indutor do CCH; Proposta e realização de um circuito inédito para definir o resistor de controle, via porta paralela do PC, de modo simples e de fácil reprodução. Com relação aos bilhares foram obtidas as seguintes realizações: Definição de um novo tipo de bilhar (Bilhar Newtoniano de Garms & Andrade); Desenvolvimento da análise detalhada das equações de simulação dos bilhares empregados nos Estudos de Caso. Ao rediscutir-se a Lógica Seqüencial Fuzzy definiu-se e desenvolveu-se, por meio da aplicação de realimentação em Circuitos Seqüenciais Fuzzy nos Sistemas Dinâmicos, um Astável Fuzzy (oscilações não-periódicas), o qual exemplifica um SDFI. Finalmente realizaram-se algumas interpretações da Física pela Teoria Fuzzy, utilizando-se o conceito de SDFI\'s. / A mapping of analytical tools for representation and computational treatment of Fuzzy Systems was made in this thesis. This mapping evidenced the existence of relations and the adequacy of the use of the Fuzzy Theory in the models construction for the problems solution involving dynamic systems e, in particular, of chaotic systems. A differentiation was considered about two types of Fuzzy Dynamic Systems - the Intrinsic Fuzzy Dynamic Systems (IFDS) and the Extrinsic Fuzzy Dynamic Systems (EFDS). The EFDS in the Fuzzy modeling is used for the problems solution of trajectories setting in chaotic systems. Case Studies had been developed that allow to verify, by means of simulation in billiards and tests in circuit of Chua (implemented in physical prototype), the adequacy of the use of this strategy in the solution of these problems. Related with Chua circuit, can be mentioned the following achievements: Computational treatment on real circuit; Use of a 8-bits AD converter followed by lowpass filter to compensate this low resolution signals reading; Use of gyrator circuit to implement the inductor used in this circuit; Proposal and accomplishment of a circuit to define the control resistor, via PC parallel port, of simple reproduction. Related with billiards, the following achievements are mentioned: Definition of a new billiard - Garms & Andrade Newtonian Billiard; Development of detailed equations of the simulations billiards analysis. When discussing again the Sequential Logic Fuzzy, is defined and developed, by means of the application of feedback in Sequential Circuits Fuzzy in the Dynamic Systems, an Astable Fuzzy (non-periodic oscillations), which exemplifies an IFDS. Finally, some interpretations of the Physics for the Fuzzy Theory are also presented with the use of the IFDS concept.
327

FUZZY ARCH模式的建構與預測:以台灣加權指數為例 / Construct FUZZY ARCH model and Forecast

林士貴 Unknown Date (has links)
ARCH在財務分析近來頗受重視,然而實務在建構ARCH模式時參數估計值很難有效估計,而且參數數字本身亦常存在不確定性,其原因可能來自時間數列資料的模糊的性質。利用此一假性的數值來建構模式影響預測,也可能擴大預測結果和實際狀況的誤差,很難讓一般投資者使用並判斷。本文在建構ARCH模式中,加入模糊邏輯概念,以符合實際情況在建構ARCH模式時參數動態的不確定性。嘗試以模糊數的來建構股價加權指數FUZZY ARCH模式,進一步預測,並與ARCH模式作比較分析。 / ARCH is more emphasized in financial analysis recently. However, it is difficult to estimate the parameters of ARCH model in practice. Because of the fuzzy property in time series , there exists the uncertainty in the parameters. Use the fictitious value to construct model and forecast the model will make the errors largely between the forecasts and the practical ones. In this thesis, we add the concept of the fuzzy logic to construct the ARCH model in order to conform the real situation. Also, an analysis of the stock data is provided.
328

A Study on Fuzzy Temporal Data Mining

Lin, Shih-Bin 06 September 2011 (has links)
Data mining is an important process of extracting desirable knowledge from existing databases for specific purposes. Nearly all transactions in real-world databases involve items bought, quantities of the items, and the time periods in which they appear. In the past, temporal quantitative mining was proposed to find temporal quantitative rules from a temporal quantitative database. However, the quantitative values of items are not suitable to human reasoning. To deal with this, the fuzzy set theory was applied to the temporal quantitative mining because of its simplicity and similarity to human reasoning. In this thesis, we thus handle the problem of mining fuzzy temporal association rules from a publication database, and propose three algorithms to achieve it. The three algorithms handle different lifespan definitions, respectively. In the first algorithm, the lifespan of an item is evaluated from the time of the first transaction with the item to the end time of the whole database. In the second algorithm, an additional publication table, which includes the publication date of each item in stores, is given, and thus the lifespan of an item is measured by its entire publication period. Finally in the third algorithm, the lifespan of an item is calculated from the end time of the whole database to its earliest time in the database for the item to be a fuzzy temporal frequent item within the duration. In addition, an effective itemset table structure is designed to store and get information about itemsets and can thus speed up the execution efficiency of the mining process. At last, experimental results on two simulation datasets compare the mined fuzzy temporal quantitative itemsets and rules with and without consideration of lifespans of items under different parameter settings.
329

A Neuro-Fuzzy Approach for Classificaion

Lin, Wen-Sheng 08 September 2004 (has links)
We develop a neuro-fuzzy network technique to extract TSK-type fuzzy rules from a given set of input-output data for classification problems. Fuzzy clusters are generated incrementally from the training data set, and similar clusters are merged dynamically together through input-similarity, output-similarity, and output-variance tests. The associated membership functions are defined with statistical means and deviations. Each cluster corresponds to a fuzzy IF-THEN rule, and the obtained rules can be further refined by a fuzzy neural network with a hybrid learning algorithm which combines a recursive SVD-based least squares estimator and the gradient descent method. The proposed technique has several advantages. The information about input and output data subspaces is considered simultaneously for cluster generation and merging. Membership functions match closely with and describe properly the real distribution of the training data points. Redundant clusters are combined and the sensitivity to the input order of training data is reduced. Besides, generation of the whole set of clusters from the scratch can be avoided when new training data are considered.
330

A Study of Management Competency Assessment Model and Succession Plan in Semiconductor Assembly and Testing Industry ¡V Case of A company

Yu, Ching-wen 02 September 2005 (has links)
The semiconductor industry plays an important role in the economic development of Taiwan. Under continuous technology advancement and global division of labor, the industry relies on high performance teams consisted of outstanding talents for competitiveness. However, the mere clustering of talents is not guarantee for high performance. The manager plays a critical role in the organization. Therefore, the selection and cultivation of the manager is a challenging issue to the organization and the human resource manager. This study employed questionnaire survey and literature review to study a case company in the semiconductor assembly and testing industry. There were totally 51 copies issued for Manager level (42 copies were collected) and 17 copies issued for Director level and above (16 copies were collected). It used Fuzzy Delphi Method to discuss the management competency evaluation indices of the case company, and used the Fuzzy Analytic Hierarchy Process of Multi-Criteria Decision Making Methods to construct a management competency assessment model. The model is used for decision-making on talents, and explores the current talents cultivation system, in order to discuss the practice of cultivating talents with management competency as successors. This study used Fuzzy Delphi Method, Fuzzy Analytic Hierarchy Process, and single case research method to analyze and investigate the case company. The findings are as follows: 1. The priority of importance of management competency assessment indices for different levels of management. There are 5 indices and 24 sub-indices. The importance analysis shows the priority of important management skill of different management levels, according to their weight ranking for leadership cluster, personality cluster, personnel communication cluster, business administion cluster and operation execution cluster, in order to show the difference in demand for management competency at different levels. 2. Establishing weight system for the management competency assessment indices The results of the weight system show the relative importance of the assessment indices for the reference of management competency related activities and basis for managers in screening. 3. Practice of cultivating talents with management competency as successors The discussion on the system employed by the case company show the feasibility of the practice of cultivating talents with management competency as successors, and suggestions are provided for future system.

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