Results 1  10
of
36
Fuzzy sets and probability : Misunderstandings, bridges and gaps
 In Proceedings of the Second IEEE Conference on Fuzzy Systems
, 1993
"... This paper is meant to survey the literature pertaining to this debate, and to try to overcome misunderstandings and to supply access to many basic references that have addressed the "probability versus fuzzy set" challenge. This problem has not a single facet, as will be claimed here. Moreover it s ..."
Abstract

Cited by 39 (5 self)
 Add to MetaCart
This paper is meant to survey the literature pertaining to this debate, and to try to overcome misunderstandings and to supply access to many basic references that have addressed the "probability versus fuzzy set" challenge. This problem has not a single facet, as will be claimed here. Moreover it seems that a lot of controversies might have been avoided if protagonists had been patient enough to build a common language and to share their scientific backgrounds. The main points made here are as follows. i) Fuzzy set theory is a consistent body of mathematical tools. ii) Although fuzzy sets and probability measures are distinct, several bridges relating them have been proposed that should reconcile opposite points of view ; especially possibility theory stands at the crossroads between fuzzy sets and probability theory. iii) Mathematical objects that behave like fuzzy sets exist in probability theory. It does not mean that fuzziness is reducible to randomness. Indeed iv) there are ways of approaching fuzzy sets and possibility theory that owe nothing to probability theory. Interpretations of probability theory are multiple especially frequentist versus subjectivist views (Fine [31]) ; several interpretations of fuzzy sets also exist. Some interpretations of fuzzy sets are in agreement with probability calculus and some are not. The paper is structured as follows : first we address some classical misunderstandings between fuzzy sets and probabilities. They must be solved before any discussion can take place. Then we consider probabilistic interpretations of membership functions, that may help in membership function assessment. We also point out nonprobabilistic interpretations of fuzzy sets. The next section examines the literature on possibilityprobability transformati...
Possibility Theory and Data Fusion in Poorly Informed Environments
 Control Eng. Practice
, 1994
"... Some data fusion problems seem to be naturally handled in the framework of possibility theory. As an example, the problem of modelling expert knowledge about numerical parameters in the field of reliability is reconsidered in that framework. Usually expert opinions about quantities such as failure r ..."
Abstract

Cited by 21 (5 self)
 Add to MetaCart
Some data fusion problems seem to be naturally handled in the framework of possibility theory. As an example, the problem of modelling expert knowledge about numerical parameters in the field of reliability is reconsidered in that framework. Usually expert opinions about quantities such as failure rates are modelled, assessed and pooled in the setting of probability theory. In this paper, we formulate a model of expert opinion by means of possibility distributions that are thought to better reflect the imprecision pervading expert judgments. They are weak substitutes to unreachable subjective probabilities. Assessment evaluation is carried out in terms of accurateness and level of precision, respectively measured by membership grades and fuzzy cardinality indices. Lastly, elaborating from previous works on data fusion using possibility theory, we present various pooling modes with their formal model under various assumptions concerning the sources of information. This framework is part...
Learning to Recognize Volcanoes on Venus
, 1998
"... Dramatic improvements in sensor and image acquisition technology have created a demand for automated tools that can aid in the analysis of large image databases. We describe the development of JARtool, a trainable software system that learns to recognize volcanoes in a large data set of Venusian ima ..."
Abstract

Cited by 19 (2 self)
 Add to MetaCart
Dramatic improvements in sensor and image acquisition technology have created a demand for automated tools that can aid in the analysis of large image databases. We describe the development of JARtool, a trainable software system that learns to recognize volcanoes in a large data set of Venusian imagery. A machine learning approach is used because it is much easier for geologists to identify examples of volcanoes in the imagery than it is to specify domain knowledge as a set of pixellevel constraints. This approach can also provide portability to other domains without the need for explicit reprogramming; the user simply supplies the system with a new set of training examples. We show how the development of such a system requires a completely different set of skills than are required for applying machine learning to "toy world" domains. This paper discusses important aspects of the application process not commonly encountered in the "toy world," including obtaining labeled training d...
Aggregating disparate estimates of chance
, 2004
"... We consider a panel of experts asked to assign probabilities to events, both logically simple and complex. The events evaluated by different experts are based on overlapping sets of variables but may otherwise be distinct. The union of all the judgments will likely be probabilistic incoherent. We ad ..."
Abstract

Cited by 19 (4 self)
 Add to MetaCart
We consider a panel of experts asked to assign probabilities to events, both logically simple and complex. The events evaluated by different experts are based on overlapping sets of variables but may otherwise be distinct. The union of all the judgments will likely be probabilistic incoherent. We address the problem of revising the probability estimates of the panel so as to produce a coherent set that best represents the group’s expertise.
Unifying practical uncertainty representations: I. Generalized pboxes
 International Journal of Approximate Reasoning
"... Abstract. There exist several simple representations of uncertainty that are easier to handle than more general ones. Among them are random sets, possibility distributions, probability intervals, and more recently Ferson’s pboxes and Neumaier’s clouds. Both for theoretical and practical considerati ..."
Abstract

Cited by 10 (5 self)
 Add to MetaCart
Abstract. There exist several simple representations of uncertainty that are easier to handle than more general ones. Among them are random sets, possibility distributions, probability intervals, and more recently Ferson’s pboxes and Neumaier’s clouds. Both for theoretical and practical considerations, it is very useful to know whether one representation is equivalent to or can be approximated by other ones. In this paper, we define a generalized form of usual pboxes. These generalized pboxes have interesting connections with other previously known representations. In particular, we show that they are equivalent to pairs of possibility distributions, and that they are special kinds of random sets. They are also the missing link between pboxes and clouds, which are the topic of the second part of this study. 1.
Eliciting Honest Reputation Feedback in a Markov Setting
"... Recently, online reputation mechanisms have been proposed that reward agents for honest feedback about products and services with fixed quality. Many realworld settings, however, are inherently dynamic. As an example, consider a web service that wishes to publish the expected download speed of a fi ..."
Abstract

Cited by 6 (6 self)
 Add to MetaCart
Recently, online reputation mechanisms have been proposed that reward agents for honest feedback about products and services with fixed quality. Many realworld settings, however, are inherently dynamic. As an example, consider a web service that wishes to publish the expected download speed of a file mirrored on different server sites. In contrast to the models of Miller, Resnick and Zeckhauser and of Jurca and Faltings, the quality of the service (e. g., a server’s available bandwidth) changes over time and future agents are solely interested in the present quality levels. We show that hidden Markov models (HMM) provide natural generalizations of these static models and design a payment scheme that elicits honest reports from the agents after they have experienced the quality of the service. 1
On the Use of Imprecise Probabilities in Reliability
 Quality and Reliability Engineering International
, 2004
"... Theory of imprecise probability generalizes classical probability theory, by assigning to each event an interval instead of a single number. In this paper, we briefly discuss this generalization and some recently suggested applications of imprecise probabilities in reliability. We also comment on ..."
Abstract

Cited by 5 (3 self)
 Add to MetaCart
Theory of imprecise probability generalizes classical probability theory, by assigning to each event an interval instead of a single number. In this paper, we briefly discuss this generalization and some recently suggested applications of imprecise probabilities in reliability. We also comment on challenges for research and applications.
DAM RISK MANAGEMENT
"... This paper presents a dam safety decisionmakers, and owners, perspective of the emerging and arguably juvenile discipline of dam risk management using formal, analytically based methods of risk analysis. It is founded on almost tenyears of detailed investigations into all aspects of risk analysis ..."
Abstract

Cited by 4 (0 self)
 Add to MetaCart
This paper presents a dam safety decisionmakers, and owners, perspective of the emerging and arguably juvenile discipline of dam risk management using formal, analytically based methods of risk analysis. It is founded on almost tenyears of detailed investigations into all aspects of risk analysis as applied to dams including several experimental applications of proposed approaches by BC Hydro. The paper provides a basis for concluding that while formal analytically based dam risk management can be expected to endure in the long term, its form will continue to evolve and necessarily will be somewhat different to what was (and still is by some) envisaged in the early to mid1990’s. This paper focuses on water retaining embankment dams in keeping with the geotechnical theme of the conference. Although some of the principles discussed regarding dam risk management will equally apply to tailings impoundments and concrete dams. According to the world register of dams there are about 30,000 significant water retaining embankment
Generalized Partition Testing Via Bayes Linear Methods
, 2001
"... This paper explores the use of Bayes linear methods related to partion testing for software. If a ..."
Abstract

Cited by 3 (2 self)
 Add to MetaCart
This paper explores the use of Bayes linear methods related to partion testing for software. If a