Differential calculus of fuzzy multi-variable functions and its applications to fuzzy partial differential equations

摘要

In this study, we deal with the concept of directional derivatives for fuzzy multi-variable functions and give explicit expressions for their directional derivatives. We give some applications of this concept as Green's identity for fuzzy multi-variable functions and Neumann boundary value problems. The fuzziness variations of a fuzzy multi-variable function according to the changing of the directions at a given point are examined. Moreover, we provide solutions to wave equations with fuzzy initial values. Some examples are presented to illustrate the results. (C) 2019 Elsevier B.V. All rights reserved.