The Gray Approximation Of Ideal Solution In The Multi-objective Decision-making

Multi-objective decision-making is the new research field that several subjects cross. Tt originated from operations research , economics and psychology . But the multi-objective decision-making problem is difficult . With the development of technology and cognition, people begin to pay close attention to all respects of the question . They always hope to carry on the consideration of many angles in many aspects to the question and scheme . They hope to make the problem solved satisfactorily. But all goals of the problem can not be always synthesized to a new synthetical goal directly .There may be correlation or contradictions in a lot of goals. They maybe have nothing to do with each other. So multi-objective decision-making problem is a very difficult problem.For multi-objective decision-making problem, experts often directly provide the weights directly, then linear into a synthetical goal. The weights not obviously given by one expert are possibly different from those by others. Therefore , there may be many greater human errors by this way . And it even results of different decision . Sand , an American operations research expert, put up with the analytic hiberarchy process (AHP) to solve those problems in 1970's. AHP is the way in which experts classify the characteristic indexes in terms of their importance to construct the matrix of judging. The matrix can be used to calculate out weights of the indexed .Obviously, the error in this way is smaller. APH uses hierarchical structure model to make people's judge more streaky and systematized . And it make up for the limit of people's thinking ability . so it be used widely in a lot of fields . Experts uses APH to classfy goals, but there are error. Furthermore, there lies error during the computational process of APH .In 1982, Professor Deng Julong of Central China university of technology put forward for the Grey System concept at first, and built up the Grey System theory. The grey relation grade of the Grey System theory offer us a grey measurement to measure things' relative degree . This way can avoid the weight problem . This paper popularize the grey relation grade's uses. And it puts forward for the way to substitute grey relation grade for traditional distance. Grey relation grade and TOPSIS come into being a new multi-objective decision-making method. Because this way substitutes grey relation grade for traditional distance, it can used on condition that there are more complicated goals, or it is difficult to provide weight directly or to classfy goals . This paper illustrate as Synthetical evaluation on technology and economy in the technics of dehydrating natural gas of West Sichuan to this way.