A fuzzy controller can be seen as an algorithm that, given a fuzzy set (input) and a set of linguistic rules, computes the degree of possibility of every control value. Using a valid and complete proof system for possibilistic logic, we prove that fuzzy controllers enjoy the following property: every possibility measure that satisfies the degrees of possibility of input and linguistic rules als...

There are a lot of problems in engineering which are connected with the necessity not to neglect the influence of uncertainties in parameters (these are for example seismic vibrations, wind loaded structures and imperfection sensitive structures). Fuzzy numbers and possibility theory are used for problems where uncertainties in definition of input data do not allow for a treatment by means of p...

The Fault Mode Effects and Criticality Analyses (FMECA), describe the impact of identified faults. They form an important category of knowledge gathered during the design phase of a satellite, and are used also for diagnosis activities. This paper proposes their extension, allowing a finer representation of the available knowledge, at approximately the same cost, through the introduction of an ...

Risk aversion is one of the main themes in risk theory. Risk theory is treated usually by probability theory. The aim of this paper is to propose an approach of the risk aversion by possibility theory initiated by Zadeh in 1978 as an alternative of probability theory in the modeling of uncertain situations. The main notions studied in this paper are the possibilistic risk premium and the possib...

In this contribution a representation of imperfect spatial information is proposed based on linguistic qualifiers within fuzzy set theory and possibility theory. By adopting a Fuzzy Object Oriented Database approach new data types for representing geographic entities characterized by either unsharp boundaries or indeterminate boundaries and relationships are defined. Finally, the evaluation mec...

The uncertainty of a financial market is traditionally dealt with probabilistic approaches. However, there are many non-probabilistic factors that affect the financial markets such that the return rate of risky assets may be regarded as fuzzy number, which is a powerful tool used to describe an uncertain environment with vagueness and ambiguity and some type of fuzziness. In this paper, the con...

Within the customer–subcontractor negotiation process, the first problem of the subcontractor is to provide the customer with a reliable order lead-time although his workload is partially uncertain. Actually, a part of the subcontractor workload is composed of orders under negotiation which can be either confirmed or cancelled. Fuzzy logic and possibility theory have widely been used in schedul...

In this paper a general bottleneck combinatorial optimization problem with uncertain element weights modeled by fuzzy intervals is considered. A rigorous possibilistic formalization of the problem and solution concepts in this setting that lead to finding robust solutions under fuzzy weights are given. Some algorithms for finding a solution according to the introduced concepts and evaluating op...

The paper presents the evaluation of the segmentation of MR images using the multispectral fusion approach in the possibility theory context. the process of fusion consists of three parts : (1) information extraction, (2) information aggregation, and (3) decision step. Information provided by T2-weighted and PDweighted images is extracted and modeled separately in each one using fuzzy logic, fu...

This paper presents an intelligent diagnosis method for a rolling element bearing; the method is constructed on the basis of possibility theory and a fuzzy neural network with frequency-domain features of vibration signals. A sequential diagnosis technique is also proposed through which the fuzzy neural network realized by the partially-linearized neural network (PNN) can sequentially identify ...