On the existence of solutions to periodic boundary value problems for fuzzy linear differential equations

In this work, we provide sufficient conditions which guarantee the existence of solutions to periodic boundary value problems for first-order linear fuzzy differential equations by using generalized differentiability and switching points. In comparison with some previous works, we consider equations whose coefficient may change its sign a finite number of times in the interval of interest. We also study the existence of solutions which are crisp (or real) at the switching points where the diameter of the level sets changes from nonincreasing to nondecreasing character. (C) 2012 Elsevier B.V. All rights reserved.