With the rapidly growing volumes of data from various sources, new tools and computational theories are required to extract useful information (knowledge) from large databases. Data mining techniques such as association rules have been proved to be effective in searching hidden knowledge in a large database. However, if we want to extract knowledge from data with temporal components, it becomes necessary to incorporate temporal semantics with the traditional data mining techniques. As mining techniques evolves, mathematical techniques become more involved to help improve the quality and diversity of mining. Fuzzy theory is one that has been adopted for this purpose. Up to now, many approaches have been proposed to discover temporal association rules or fuzzy association rules, respectively. However, no work is contributed on mining fuzzy temporal patterns. We propose in this thesis two data mining systems for discovering fuzzy temporal association rules and fuzzy periodic association rules, respectively. The mined patterns are expressed in fuzzy temporal and periodic association rules which satisfy the temporal requirements specified by the user. Temporal requirements specified by human beings tend to be ill-defined or uncertain. To deal with this kind of uncertainty, a fuzzy calendar algebra is developed to allow users to describe desired temporal requirements in fuzzy calendars easily and naturally. Moreover, the fuzzy calendar algebra helps the construction of desired time intervals in which interesting patterns are discovered and presented in terms of fuzzy temporal and periodic association rules. In our system of mining fuzzy temporal association rules, a border-based mining algorithm is proposed to find association rules incrementally. By keeping useful information of the database in a border, candidate itemsets can be computed in an efficient way. Updating of the discovered knowledge due to addition and deletion of transactions can also be done efficiently. The kept information can be used to help save the work of counting and unnecessary scans over the updated database can be avoided. Simulation results show the effectiveness of the proposed system for mining fuzzy temporal association rules. In our mining system for discovering fuzzy periodic association rules, we develop techniques for discovering patterns with periodicity. Patterns with periodicity are those that occur at regular time intervals, and therefore there are two aspects to the problem: finding the pattern, and determining the periodicity. The difficulty of the task lies in the problem of discovering these regular time intervals, i.e., the periodicity. Periodicites in the database are usually not very precise and have disturbances, and might occur at time intervals in multiple time granularities. To discover the patterns with fuzzy periodicity, we utilize the information of crisp periodic patterns to obtain a lower bound for generating candidate itemsets with fuzzy periodicities. Experimental results have shown that our system is effective in discovering fuzzy periodic association rules.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Bing Kwan, Florida State University, College of Engineering, Dept. of Electrical and Computer Engineering. Title and description from dissertation home page (viewed June 16, 2004). Includes bibliographical references.

Fuzzy relation equations are becoming extremely important in order to investigate the optimal solution of the inverse problem even though there is a restrictive condition for the availability of the solution of such inverse problems. We discussed the methods for finding the optimal (maximum and minimum) solution of inverse problem of fuzzy relation equation of the form $R \circ Q = T$ where for both cases R and Q are kept unknown interchangeably using different operators (e.g. alpha, sigma etc.). The aim of this study is to make an in-depth finding of best project among the host of projects, depending upon different factors (e.g. capital cost, risk management etc.) in the field of civil engineering. On the way to accomplish this aim, two linguistic variables are introduced to deal with the uncertainty factor which appears in civil engineering problems. Alpha-composition is used to compute the solution of fuzzy relation equation. Then the evaluation of the projects is orchestrated by defuzzifying the obtained results. The importance of adhering to such synopsis, in the field of civil engineering, is demonstrated by an example.

The broad goal in this thesis is to enumerate elements and fuzzy subsets of a finite set enjoying some useful properties through the well-known counting technique of the principle of inclusion-exclusion. We consider the set of membership values to be finite and uniformly spaced in the real unit interval. Further we define an equivalence relation with regards to the cardinalities of fuzzy subsets providing the Möbius function and Möbius inversion in that context.

Made available in DSpace on 2014-06-11T19:24:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-14Bitstream added on 2014-06-13T18:52:59Z : No. of bitstreams: 1 dias_chbb_me_rcla.pdf: 692647 bytes, checksum: 869fdb9734d900054c9edcfce9ca37cc (MD5) / Universidade Estadual Paulista (UNESP) / 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 / 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

Orientador: Akebo Yamakami / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-14T08:52:58Z (GMT). No. of bitstreams: 1 Verga_Juliana_M.pdf: 625534 bytes, checksum: 396d5b5c1dafff5b2fbb632e185c4a72 (MD5) Previous issue date: 2009 / Resumo: A teoria dos grafos é comumente utilizada na área da engenharia para resolver problemas que podem ser representados na forma de redes. Dentre diversos problemas abordados, o problema de fluxo multiproduto é um dos que também podem ser modelados por grafos. Este trabalho apresenta uma proposta de solução para o problema de fluxo multiproduto fuzzy. O problema foi modelado através de um grafo, cujos nós representam pontos de oferta e demanda de produtos, os quais trafegam pelos arcos da rede. O algoritmo proposto visa encontrar soluções factiveis e boas para o problema de fluxo multiproduto fuzzy em redes com incertezas nos custos e capacidades, contendo múltiplas origens e múltiplos destinos. As incertezas são modeladas por meio da teoria dos conjuntos fuzzy, que tem sido aplicada com sucesso em problemas com incertezas. / Abstract: The graph theory is commonly used in the area of engineering to solve problems that can be represented in the form of nets. Among several problems, the multicommodity flow problem is one that can be modeled by graphs. This work presents an approach for solving the fuzzy multicommodity flow problem. The problem was modeled through a graph whose nodes represent points of supply and demand of commodities, which pass through arcs of the network. Our algorithm aims to find a set of good feasible solutions for the fuzzy multicommodity flow problem in networks with uncertainties in the costs and capacities, containing multiple origins and multiple destinations. The uncertainties are modeled by means of the fuzzy sets theory, which has been successfully applied to problems with uncertainties. / Mestrado / Automação / Mestre em Engenharia Elétrica

Orientadores: Akebo Yamakami, Marcia Tomie Takahashi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T13:05:12Z (GMT). No. of bitstreams: 1 Hernandes_Fabio_D.pdf: 995506 bytes, checksum: c4a27a827d2ca5ec109571ba03e4e094 (MD5) Previous issue date: 2007 / Resumo: A teoria de grafos é uma importante área da programação matemática, tendo um importante papel em áreas tais como engenharia e pesquisa operacional. Em particular, ela fornece ferramentas para tratar problemas de redes (tais como: alocação, caminho mínimo, fluxo máximo, etc.), que têm aplicações em diversas subáreas da engenharia (por exemplo: telecomunicações, transporte, manufatura, etc.). Estas aplicações podem, entretanto, possuir incertezas em seus parâmetros ou em sua estrutura. Baseado nisto, este trabalho trata de algumas importantes aplicações de problemas em grafos com incertezas em seus parâmetros ou estruturas e propõe algoritmos para encontrar suas soluções. As aplicações estudadas são: problemas de caminho mínimo, problemas de fluxo máximo, problemas de fluxo de custo mínimo e problemas de coloração de grafos. As incertezas são modeladas por meio da teoria dos conjuntos fuzzy, que tem sido aplicada com sucesso em problemas com incertezas e imprecisões / Abstract: The graph theory is an important area of mathematical programming, it has an important role in fields such as engineering and operational research. In particular, it provides the tools to tackle network problems (e.g. allocation, shortest path, maximum flow, etc), which have applications in several sub areas of engineering (e.g. telecommunications, transportation, manufacturing, etc). These applications can, however, possess uncertainties in their parameters or in their structure. Based on that, this work addresses some important applications of graph problems with uncertainties in their structure or parameters and proposes algorithms to find the solution to them. The applications studied are: shortest path problems, maximum flow problems, minimum cost flow problems and graph coloring problems. The uncertainties are modeled by means of the fuzzy sets theory, which has been successfully applied to problems with uncertainties and vagueness / Doutorado / Automação / Doutor em Engenharia Elétrica

We present data structures and algorithms for sets and some generalizations thereof (fuzzy sets, multisets, and fuzzy multisets) available for R through the sets package. Fuzzy (multi-)sets are based on dynamically bound fuzzy logic families. Further extensions include user-definable iterators and matching functions. (authors' abstract)

This work introduces some very basic concepts of category theory as built up over first-order predicate Gödel fuzzy logic (with crisp identity and the delta operator). A fuzzy variation of a classical concept of a category is considered. Then several systems of morphisms loosely based on the crisp categories Rel and Set are defined and examined. Accordingly, all the systems under consideration consist of fuzzy sets as objects and various kinds of binary fuzzy relations as morphisms. Our approach is a logic-based graded generalization of crisp (clas- sical) category-theoretical approaches to fuzzy sets, which have been initiated by Goguen. 1

by Yeung Wai Leung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 92-[96]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Fuzzy Inference and Real Intelligent Mapping --- p.1 / Chapter 1.2 --- Organization of the thesis --- p.5 / Chapter 2 --- Fuzzy Logic inference --- p.7 / Chapter 2.1 --- Fuzzy logic --- p.7 / Chapter 2.1.1 --- Fuzzy sets --- p.7 / Chapter 2.1.2 --- Operations on fuzzy sets --- p.10 / Chapter 2.2 --- Fuzzy Inference --- p.11 / Chapter 3 --- Weaknesses of fuzzy inference --- p.17 / Chapter 3.1 --- Is the use of linguistic fuzzy if-then rules and membership func- tions a good means of representing human expert knowledge? --- p.17 / Chapter 3.2 --- Role of conventional fuzzy inference doubtful if the expert knowl- edge is in the form of sampled input-output data --- p.21 / Chapter 3.3 --- Computational requirements --- p.23 / Chapter 3.4 --- Low transparency --- p.24 / Chapter 3.5 --- Analytical difficulties --- p.25 / Chapter 4 --- Real Intelligent Mapping --- p.27 / Chapter 5 --- Design of Real Intelligent Mapping Systems Using Dirichlet Tessellation --- p.33 / Chapter 5.1 --- Dirichlet tessellation for function approximation --- p.34 / Chapter 5.2 --- Identification of a DT based RIM system by least-squares --- p.42 / Chapter 5.3 --- Examples --- p.48 / Chapter 5.3.1 --- Defining the problem --- p.48 / Chapter 5.3.2 --- Balancing an inverted pendulum --- p.49 / Chapter 5.3.3 --- Balancing an inverted pendulum with cart --- p.53 / Chapter 5.3.4 --- Truck backing-up --- p.56 / Chapter 5.3.5 --- Chaotic time series prediction --- p.60 / Chapter 5.4 --- Interactive CAD platform for RIM systems design --- p.63 / Chapter 6 --- Analysis of Dirichlet tessellation based Real Intelligent Mapping Systems --- p.67 / Chapter 6.1 --- Local Stability Analysis of DT Based RIM Systems --- p.69 / Chapter 6.1.1 --- Balancing an inverted pendulum --- p.71 / Chapter 6.1.2 --- Truck backing-up --- p.73 / Chapter 6.2 --- Global stability analysis of DT based RIM systems --- p.74 / Chapter 6.3 --- Design of a stable DT based RIM system --- p.79 / Chapter 6.4 --- A method for analyzing Second order DT based RIM systems --- p.82 / Chapter 6.5 --- Piecewise-polynomial real domain representation of a class of fuzzy controller and its stability --- p.85 / Chapter 7 --- Conclusion --- p.90 / Bibliography --- p.92