Application Of Weighting Method For Railway Safety Indexes Of Passenger Transportation Based On Maximizing Variance

China’s economy has made tremendous leaps in the past two decades.Residents’travel intention has been greatly enhanced,and the demand for travel has been increasing rapidly.Among the different transportation methods for long-distance travelers,railway transportation has become the first choice because of its large capacity,fast speed and little influence by natural conditions.According to the"Medium and Long-term Railway Network Plan",by 2020,China’s high-speed railway will increase to 30,000 kilometers.With the continuous improvement of transport capacity,the requirements for safety has been improved.Therefore,the establishment of a scientific and reasonable evaluation system for railway passenger transport safety,especially given reasonable weight indexes in the system,has great significance for the Safety Management of Railway Transportation.Based on the method of maximizing the variance,this paper proposes a set of index weighting methods for railway passenger transport safety evaluation system.On the basis of experts’judgment on the weight of each index,the weights of indexes are optimized by using the dispersion degree between the evaluation results of the evaluated objects.Firstly,the paper analyzed the commonly security analysis methods and weight determination methods,mainly discussed the main ideas and weight determining process of subjective weighting method,objective weighting method and combination weighting method.On this basis,the paper summarizes the standard of index weighting method,and make a theoretical foundation for the establishment of the weighting method of maximizing variance of railway passenger transport safety index.Secondly,five typical accidents which have huge influence on railway passenger transport safety are summarized and the factors affecting railway passenger transport safety are divided into aspects of personnel,equipment,environment and management.After the analysis of safety risks,the safety evaluation index system of railway passenger transport is established from four aspects.Thirdly,based on the characteristics of railway passenger transport safety evaluation system,the weighting method is applied using the idea of maximizing the variance of safety evaluation results.By using the fuzzy set theory,the weight interval is divided into nine levels.The confidence of experts is calculated by the objective background of experts.The initial weights are determined by results of the expert judgement on each index and experts’ confidence.A method of fuzzy probability of weight level is introduced to generate the range of each index’s weight.Designing a genetic algorithm so that each weight can be searched in its range space to maximize the variance of the safety evaluation results.Finally,an example is given to illustrate the effectiveness of the proposed variance maximization method.Meantime,Rough set method and entropy method is used for comparison.In the comparison results,the weighting method using maximizing variance is better than the ordinary weighting method,this method combined the subjective evaluation information of experts and scatter degree between different railway transport enterprises.The rationality and superiority of the weighting method using maximum variance of railway passenger transport safety system are verified.