Computation of Uncertain Parameters by Using Fuzzy Synthetic Decision and D-S Theory

In the course of design, decision making and other problems alike being settled, parameter, whose value is limited to a Real-interval, can often be found. Such parameters are named Uncertain Parameters in this paper. The value of such a parameter is usually determined by several factors, which are named Decisive Factors of the parameter. The research in this paper aims at how to specify an uncertain parameter if it fails to get a function about the Uncertain Parameter and its decisive factors, it can only get a group of production rules expressing the restrictive relationship between the decisive factors and the uncertain parameter. To settle this problem, a method based on Fuzzy Comprehensive Decision is proposed in this study. Another method based on the Combination Rule in Dempster-Shafer Theory of Evidence (called “D-S Rule” for short) is also proposed to solve the problem. Usually, the results of the two methods are similar to each other. Relatively, the former one is simpler and with less calculation work.