Cyber fuzzy assessment methods

Abstract

The assessment of a system's performance is a very important task for its operation, because the results obtained by this action help the designer/user of the system to correct its weaknesses, thus making it more effective. The assessment methods usually utilized in practice are based on the principles of classical, bivalent logic (yes-no). However, in our everyday life they frequently appear assessment situations involving a degree of uncertainty and (or) ambiguity. Fuzzy logic, due to its nature of characterizing a case with multiple values, offers rich resources for dealing with such kind of situations. This gave us several times in past the impulse to apply principles of fuzzy logic for assessment purposes using as tools the corresponding system's total uncertainty (e.g. see [2] and its relevant references, Section of [3], etc) the Center of Gravity (COG) defuzzification technique (e.g. Section of [3], [4], etc) as well as the Triangular (TFAM) (e.g. [1]) and Trapezoidal (TRFAM) (e.g. [5]) Fuzzy Assessment Models, which are recently developed variations of the COG technique. In this presentation we shall use the Fuzzy Numbers (FNs), and in particular the Triangular (TFN) (e.g. [6]) and Trapezoidal (TpFN) Fuzzy Numbers, as an alternative assessment tool. FNs play a fundamental role in fuzzy mathematics, analogous to the role played by the ordinary numbers in classical mathematics. Our results are illustrated by an example, while this alternative assessment approach is compared with the assessment methods of the bivalent (calculation of the means, GPA index) and fuzzy logic (see above) that we have already used in earlier works.