Research On Combination Method For Fuzzy Period Risk

Firstly, the concept of period risk and fuzzy period risk for network planning is put forward in the paper. According to the need to analyze fuzzy period risk, some types of period is discussed: calculated period of network planning maybe certainty, random variable or fuzzy number; and planning period all is not certainty, probably is random variable. This paper is based on network planning, fuzzy mathematics and method of simulation. In accordance with different types of combination of calculated period and planning period, the calculation to fuzzy period risk falls into two broad classes, and attempt research on combination method for fuzzy period risk.First class is for probable network. Calculated period is random variable, and planning period is certainty or random variable. A fuzzy standard is brought up by which general event is in place of fuzzy event, and fuzzy period risk can be found by conventional knowledge of fuzzy event probability after membership function is given.Second class is for fuzzy network. Calculated period is fuzzy number, and planning period is certainty or random variable. Using the expression way of general event probability to fuzzy event probability, common method of probability can find fuzzy event period risk for fuzzy network planning.The calculation of fuzzy period risk for network, most of the time, cannot get a definite analytic solution. Fuzzy digital simulation method is raised based on digital simulation method in the paper, and a program is prepared for the combination method. All this makes the solution to the problem of fuzzy period risk simple, practical and utility.Taken the case of the period analysis project of NuoZaDu hydropower station standing on LuanChang River in YunNan province, combination method for fuzzy period risk is studied in the paper.