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1995 | Buch

Fundamentals of Uncertainty Calculi with Applications to Fuzzy Inference

verfasst von: Michel Grabisch, Hung T. Nguyen, Elbert A. Walker

Verlag: Springer Netherlands

Buchreihe : Theory and Decision Library

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Über dieses Buch

With the vision that machines can be rendered smarter, we have witnessed for more than a decade tremendous engineering efforts to implement intelligent sys­ tems. These attempts involve emulating human reasoning, and researchers have tried to model such reasoning from various points of view. But we know precious little about human reasoning processes, learning mechanisms and the like, and in particular about reasoning with limited, imprecise knowledge. In a sense, intelligent systems are machines which use the most general form of human knowledge together with human reasoning capability to reach decisions. Thus the general problem of reasoning with knowledge is the core of design methodology. The attempt to use human knowledge in its most natural sense, that is, through linguistic descriptions, is novel and controversial. The novelty lies in the recognition of a new type of un­ certainty, namely fuzziness in natural language, and the controversality lies in the mathematical modeling process. As R. Bellman [7] once said, decision making under uncertainty is one of the attributes of human intelligence. When uncertainty is understood as the impossi­ bility to predict occurrences of events, the context is familiar to statisticians. As such, efforts to use probability theory as an essential tool for building intelligent systems have been pursued (Pearl [203], Neapolitan [182)). The methodology seems alright if the uncertain knowledge in a given problem can be modeled as probability measures.

Inhaltsverzeichnis

Frontmatter
Chapter 1. Introduction
Abstract
The advance of science and technology is due to the desire to improve existing knowledge and to address new problems that have arisen. At any stage in the history of science, solutions to new problems require new concepts and new tools. Mathematics is called upon to formulate precisely the new concepts involved and to provide the new tools required for solutions. The mathematical theory of probability is a typical example. It serves as the backbone for the theory of statistics. Statistical techniques invade other fields, such as engineering. In engineering problems in which uncertainty is often an important factor, one borrows many statistical techniques, these being the primary body of mathematical tools available for use in uncertainty. The uncertainty involved might be due to errors in measurements, or to the lack of certain and complete knowledge of the system under consideration. But in applying these techniques, one has to be in the domain of applicability of probability theory. The success with problems such as stochastic control, identification of systems, pattern recognition, filtering, and so on, is due to the fact that these areas are assumed to be in the domain of applicability of probability theory. The knowledge that comes from uncertain information is modeled by probability measures, and the techniques are those from statistical decision theory. And it should be noted that the logic used is always the classical two-valued logic.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 2. Modeling Uncertainty
Abstract
This chapter reviews some main types of uncertainty encountered in scientific investigations. We focus on the mathematical modeling aspects of them. Two points are emphasized: (i) intelligent tasks require decision making under uncertainty, and (ii) any type of uncertainty can be represented by real valued functions.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 3. Capacities and the Choquet Functional
Abstract
In this chapter we study an important class of non-additive set functions called Choquet capacities [25] . These set functions make their appearance in uncertainty modeling in the work of Dempster [41] and Shafer [225]. Choquet’s work also pointed out an important relation between potential theory and probability theory. This relation is emphasized in Matheron [160] on distributions of random sets. Since random sets can play an essential role in uncertainty modeling (Nguyen, [184] and Hestir et al, [98]), the concept of capacity has become familiar to AI researchers. More importantly, fuzzy measures share similar properties with capacities (Sugeno [233]). For example, Choquet’s integral seems to be a reasonable way for formalizing “expected” uncertainty in the non-additive case. (See, for example, Nguyen and Walker [192]). For these reasons, we try to present here a somewhat detailed exposition of capacity theory for AI researchers.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 4. Information Measures
Abstract
This chapter is devoted to a class of nonadditive set functions in the theory of generalized information measures. Besides its relevance in the context of semantic information which becomes more and more important in knowledge representation, its contents at the technical level exhibits a connection with Choquet capacity. More importantly, its principles and tools of analysis present a striking analogy with the actual investigation of fuzzy measures. This duality is interesting its own right.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 5. Calculus of Fuzzy Concepts
Abstract
This chapter is a tutorial introduction to the mathematical modeling of fuzzy concepts and its use in computer oriented technology. It will also serve as a background for developing a theory of fuzzy measures and integrals in Chapter 6.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 6. Fuzzy Measures and Integrals
Abstract
Chapter 5 was concerned with the theory of fuzzy sets as a mathematical model to describe vague concepts, and as an extension of ordinary set theory. In a similar spirit, this chapter is about an extension of additive measures, in particular probability measures, to a more general class of non-additive set functions.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 7. Decision Making
Abstract
In this chapter we describe the role of fuzzy measures in the field of decision making. Fuzzy set theory on the whole has made significant contributions to the field. See for example the monograph of Zimmermann [281], the book of Chen and Hwang [28], and the recent book of Fodor and Roubens [68]. It has introduced the arithmetic of fuzzy numbers, fuzzy connectives, and non-additive probability measures, which are more or less fuzzy measures. After more than two decades of intensive research, one can ask about the effectiveness of these contribution to the field of decision making. We do not claim to answer such a general question, but the attempt of Billot [15] to answer it in the restricted field of economics is quite interesting. He distinguishes two main streams:
  • the direct application of the concept of fuzzy sets via the extension principle, which is a passage from the world of crisp numbers and all its restrictions to the richer but more difficult world of fuzzy numbers. This includes fuzzy number arithmetic, ranking of fuzzy numbers, preference relations, fuzzy linear programming and related topics, multicriteria decision making, and so on.
  • the introduction of non-additive probability which was not a generalization of additive probability for its sake but as a necessary tool to avoid well known paradoxes, as the Ellsberg paradox, which we will explain below. This branch includes, possibility theory, non-additive expected utility, and the works of Dempster and Shafer.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 8. Subjective Multicriteria Evaluation
Abstract
The preceding chapter presented a theoretical foundation of fuzzy measures and integrals in the field of decision making. We turn now to more practical considera tions, that of a particular decision problem: multicriteria evaluation. This kind of problem is present in many fields of applications, such as resource allocation, design of new goods, environmental planning, quality control, evaluation of creditworthiness [283], and so on. The monograph of Nijkamp et al. [193] is entirely devoted to multicriteria evaluation in physical planning. The last paragraph of this chapter will illustrate this variety by some concrete examples.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 9. Pattern Recognition and Computer Vision
Abstract
Pattern recognition is a task we (human beings) perform at every instant of our life, when we recognize the face, or the voice of a familiar person, when we read newspapers or a letter, or at a lower level, when we distinguish a chair from a desk, or a book from a pencil.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Chapter 10. Identification and Interpretation of Fuzzy Measures
Abstract
The preceding chapters have presented the theoretical material for the application of fuzzy measures and integrals to various domains, along with concrete examples. We have seen that the fuzzy integral, as an aggregation operator, is a powerful tool. Perhaps the general formulation of fuzzy integrals using t-conorms provides the widest known family of averaging operators since they include most of the weighted quasi-arithmetic means (that is, decomposable averaging operators), all associative averaging operators, OWA, and so forth. Of course, the whole family is considerably larger than that.
Michel Grabisch, Hung T. Nguyen, Elbert A. Walker
Backmatter
Metadaten
Titel
Fundamentals of Uncertainty Calculi with Applications to Fuzzy Inference
verfasst von
Michel Grabisch
Hung T. Nguyen
Elbert A. Walker
Copyright-Jahr
1995
Verlag
Springer Netherlands
Electronic ISBN
978-94-015-8449-4
Print ISBN
978-90-481-4477-8
DOI
https://doi.org/10.1007/978-94-015-8449-4