Journal of Operational Research in its Applications
Year:2008 | Volume:5 | Issue:19|Papers Count:8

In this paper Homotopy Perturbation Method (HPM) to solve fuzzy Fredholm integral equations is proposed. The method is discussed in details and it is illustrated by solving some numerical examples.

In [1], introduce a modified variational iteration method (MVIM) for a special kind of nonlinear differential equations. In this paper, we consider variational iteration method (VIM) and MVIM (introduced in [1]) to obtain exact solution to Fisher’s equation. It is shown in this paper the application of VIM to Fisher’s equation leads to calculation of unneeded terms and more time consumed in repeated calculations for series solutions. Therefore, we use MVIM for Fisher’s equation to overcome these disadvantages.

This paper presents a numerical method for finding the solution of time-delay systems using triangular functions. We present the properties of the triangular functions. The operational matrices of integration and delay are utilized to reduce the solution of time-delay systems to the solution of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of the technique.

Let G is n− vertex graph. In 1996, Reed conjectured that g (G) £ [n/3] for every connected 3− regular G. In this paper, we introduce an algorithm in computer algebra system of MAPLE such that, by using any graph as input, we can calculate domination number g(G) and illustrated set of all dominating sets. It important that these sets choose among between (n g(G)) sets.

Many ranking methods have been proposed so far. However, there is not any method which can always give a satisfactory solution for every situation. In this paper, we propose a method for ranking fuzzy numbers based on the distance method and compare the results with other ranking methods in some examples.

The user interface design is one of the parameters that identify the efficiency of softwares. Experiences indicate that users prefer to use softwares with limited and integrated capabilities rather than comprehensive software. In this case, this paper presents the foundational guidelines on the basis of the technical options in the forms (e.g. accessibility, language setting, etc.) that are applicable to all kinds of software environments from desktop to web-based and embedded softwares. We expect this new aspect to be useful for designers to produce friendlier and more acceptable interfaces.

The fact the spectrum of an element of a complex normed algebra is nonempty is a well-known theorem. In this note we study this problem for a class of topological algebras and provide the Gelfand homomorphism for commutative continuous inverse algebras.

In some situations, some of undesirable inputs and outputs are imprecise (i.e. they are not known exactly). Therefore, in this paper we introduce undesirable imprecise data and propose a method for evaluation Decision Making Units (DMUs) with undesirable imprecise data.