I. INTRODUCTIONWide range of real world applications in many areas including economics, engineering and physics, are using linear system of equations for modeling and solving their respective problems. In many situations the estimation of the system parameters is imprecise and only some vague knowledge about the actual value of parameters is available, therefore to overcome this problem the vagueness of parameters is represented by fuzzy numbers. In many applications some of the parameters are usually represented by complex numbers which have fuzzy nature, thus it is important to develop mathematical models that would appropriately treat fuzzy complex linear systems. Circuits can be modeled in the form of fuzzy complex system of linear equations (FCSLE).A rapid growth of interest in circuit theory and simulation is seen in recent decade. A circuit simulation program (e.g., SPICES [1] and QPMDFSD [2, 3, and 4]) provides very good details in simulation of circuits. These types of software provide various facilities for obtaining best answer which is close to real form. Some contributions have been made in stability theory using functional analysis in the study of nonlinear systems, and computer-aided nonlinear network analysis [5, 6, 7, and 8]. But uncertainty in circuit parameters and environmental conditions lead to develop a new method which takes in to account uncertainty in circuit analysis. In the previous work In the aforementioned works, real coefficients are discussed but in many applications as circuit analysis, while SLE includes complex coefficients and complex variables. Also we encountered situations in circuit solving that needs solving a FSLE model which has been solved by Friedman et al. [10]. Therefore we present a Fuzzy Complex SLE, namely, FCSLE in this paper. This model works well in circuit solving. Major notes in this paper are presentation of FCSLE, and application of FSLE and FCSLE in circuit solving. Organization of this paper is as follows:
Fuzzy Complex System of Linear EquationsApplied to Circuit Analysis Taher Rahgooy, Hadi Sadoghi Yazdi, Reza MonsefiInternational Journal of Computer and Electrical Engineering, Vol. 1, No. 5 December, 2009 1793-8163 536 FSLE is explained in section III. Section IV appropriate to the proposed FCSLE and experimental results over circuit analysis are discussed in the section V. Final section includes the conclusion.
III. FUZZY SYSTEM OF LINEAR EQUATIONS
A. PreliminariesWe represented an arbitrary fuzzy number by an ordered pair of functions which should satisfy the following requirements:1.is a bounded left continuous nondecreasing function over [0,1]. 2.is a bounded left continuous nonincreasing function over [0,1]. 3.
Fig. 1 A fuzzy numberFor example, the fuzzy number (1 + r, 4 -2r) is shown in Fig. 1. A crisp number α is simply represented by By appropriate definitions the fuzzy number space becomes a convex cone E 1 which is then embedded isomorphically and isometrically into a Banach space. Definition 1. The n × n linear system of equations Cons...