In the last decade a substantial amount of work has been carried out in the context of Description Logics (DLs). DLs are a logical reconstruction of the so-called framebased knowledge representation languages, with the aim of providing a simple wellestablished Tarski-style declarative semantics to capture the meaning of the most popular features of structured representation of knowledge. A main...

Efficient handling of inexact (grey) information is an important issue for the new emerging database technology. Inexact or imprecise information has been represented and manipulated by using different techniques, including fuzzy set theory, possibility theory, IVF (Interval Valued Fuzzy) Sets, Time Petri Nets, Fuzzy Clouds, etc. In this paper, different approaches dealing with uncertainty have...

Much attention has been given in machine learning field to the study of numerous resampling techniques during the last fifteen years. In the paper the investigation of m-out-of-n bagging with and without replacement and repeated cross-validation using genetic fuzzy systems is presented. All experiments were conducted with real-world data derived from a cadastral system and registry of real esta...

In this paper, we propose the new concept of optimal solution for fuzzy variational problems based on the possibility and necessity measures. Inspired by the well–known embedding theorem, we can transform the fuzzy variational problem into a bi–objective variational problem. Then the optimal solutions of fuzzy variational problem can be obtained by solving its corresponding biobjective variatio...

We consider the internal rate of return (IRR) decision rule in capital budgeting problems with fuzzy cash flows. The possibility distribution of the IRR at any r ≥ 0, is defined to be the degree of possibility that the (fuzzy) net present value of the project with discount factor r equals to zero. Generalizing our earlier results on fuzzy capital budegeting problems [5] we show that the possibi...

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...