A Comprehensive Evaluation Of The Key Nodes Safety Efficiency And Emergency Efficiency Of Sea Lines Of Communication

In nowadays' world,along with the development of globalization,almost every country has trade relations with other countries,import and export trade has already been indispensable for these countries.More than 80%international trade cargo is transported by sea transportation today,as the carriers of sea transportation,sea lines of communication are receiving increasing attention in the researches.Sea lines of communication have been the vital economic,political,cultural and military lifelines for our country,so the safety problem attracts much scholastic attention.Strais and canals are regarded as the key nodes because of their special geographic features,and the safety status of these nodes have great impacts on the safety status of sea lines of communication.In order to make response to ensure the safety in advance,this paper researches the safey and emergency efficieny comprehensive evaluation.This paper analyses the nature and social environment of sea lines of communication key nodes based on the refenrence theory on safey and emergency efficiency of sea lines of communication key nodes.After that,this paper uses the DEA model considering nagetive input and output variables,virtual envelope and TOPSIS and so on to evaluate the single-stage efficiency and overall efficiency of safety and emergency of sea lines of communication key nodes.Firstly,sea lines of communication key nodes are selected based on their importance.Beyond that,the impact factors of safey and emergency efficiency of sea lines of communication key nodes are analysed,and then the input and output variables of safey and emergency efficiency of sea lines of communication key nodes are determined.Secondly,considering nagetive input and output variables,a evaluation model combined with virtual envelope and TOPSIS is constructed to calculate safety efficiency and emergency efficiency,the rank is also got.Thirdly,the overall efficiency is calculated by a two stage DEA model considering the evaluator's reference after analyzing the relationship between safety stage and emergency stage.Finally,noticing the efficient DMUs in the previous phase are undifferentiated,a new evaluation model combined with virtual envelope and TOPSIS and two stage DEA model considering the decision maker's reference is constructed to calculate the different efficiency values.All results are calculated and analyzed with the selected key nodes data.The results show that these methods are feasible and valid.They can provide an effective method of evaluating the safety and emergency efficiency of sea lines of communication key nodes.