Fuzzy differential equations are used in modeling problems in science and engineering. For instance, it is known that the knowledge of dynamical systems modeled by ordinary differential equations is often incomplete or vague. While, fuzzy differential equations represent a proper way to model dynamical systems under uncertainty and vagueness. In this paper, two methods for solving first order l...

This paper concerns an application of the fuzzy structures analysis (FSA) procedures of Soize to prototypical aerospace panels in MSC/NASTRAN, a large commercial finite element program. A brief introduction to the FSA procedures is first provided. The implementation of the FSA methods is then disclosed, and the method is validated by comparison to published results for the forced vibrations of ...

Whitney’s Broken-cycle Theorem states the chromatic polynomial of a graph as a sum over special edge subsets. We give a definition of cycles in hypergraphs that preserves the statement of the theorem there.

Let P(G) denote the chromatic polynomial of a graph G. Two graphs G and H are chromatically equivalent, if P(G) = P(H). A set of graphs S is called a chromatic equivalence class if for any graph H that is chromatically equivalent with a graph G in S, then H ∈S. Peng et al. (Discrete Math. 172 (1997) 103–114), studied the chromatic equivalence classes of certain generalized polygon trees. In thi...

fuzzy water quality index (fwqi) was applied in order to assess the degree of drinking water resources in yazd province, iran. thisstudy has also offered the creation of a new fuzzy water quality index (fwqi) to evaluate this tool’s applicability. 12 chemicalparameters including toxic and non-toxic heavy metals measured in 71 groundwater samples collected from drinking water resourcesin rural a...

waveguides with low confinement loss, low chromatic dispersion, and low nonlinear effects are used in optical communication systems. optical fibers can also be employed in such systems. besides optical fibers, photonic crystal fibers are also highly suitable transmission media for optical communication systems. in this paper, we introduce two new designs of index-guiding photonic crystal fiber ...

For a graphG, let P(G) be its chromatic polynomial. Two graphsG andH are chromatically equivalent if P(G)=P(H). A graph G is chromatically unique if P(H)= P(G) implies that H G. In this paper, we classify the chromatic classes of graphs obtained from K2,2,2 ∪ Pm(m 3), (K2,2,2 − e) ∪ Pm(m 5) and (K2,2,2 − 2e) ∪ Pm(m 6) by identifying the end-vertices of the path Pm with any two vertices of K2,2,...

This paper proposes an effective algorithm approach to hybrid control systems combining fuzzy logic and conventional control techniques of controlling the speed of induction motor assumed to operate in high-performance drives environment. The introducing of fuzzy logic in the control systems helps to achieve good dynamical response, disturbance rejection and low sensibility to parameter variati...