The ranking and comparing of fuzzy numbers have important practical uses, such as in risk analysis problems, decision-making, optimization, forecasting, socioeconomic systems, control and certain other fuzzy application systems. Several methods for ranking fuzzy numbers have been widely-discussed though most of them have shortcomings. In this paper, we present a new method for ranking triangular fuzzy numbers based on their incenter and inradius. The proposed method is much simpler and more efficient than other methods in the literature. Some comparative examples are also given to illustrate the advantages of the proposed method.

In this study, we present a new method for ranking generalized trapezoidal fuzzy numbers based on the incenter and inradius of a triangle. The proposed method is simple and easy to apply to real life problems. The method can also rank crisp numbers and fuzzy numbers with the same centroid point. Some comparative examples are also given to illustrate the advantages of the proposed method. Based on the proposed ranking method, we also give an application to the fuzzy risk analysis problem.

Abstract. In this paper an approximation method for the construction of reachable sets of control systems with integral constraints on the control is considered. It is assumed that the control system is non-linear with respect to the phase state vector and is linear with respect to the control vector. The admissible control functions are chosen from the ball centered at the origin with radius µ0 in Lp, p > 1. The reachable set is replaced by the set which consists of finite number of points. The estimated accuracy of the Hausdorff distance between the reachable set and the set which is approximately constructed is obtained.2000 Mathematics Subject Classification: Primary 34A34; Secondary 93B03.