Research On Some Problems In Railway Emergency Decision Making

Railway emergency decision-making is mainly based on their own experience ofdecision-makers. However, due to the limitations of knowledge of the decision-makers andtheir own pressure, the decision may exist some deficiencies. Therefore, how to makeeffective decision efficiently and timely has become an urgent.In this thesis, some issues around the railway emergency decision-making are researchedby the method of combining analysis and synthesis, theoretical research and numericalexperiments, and using multi-disciplinary knowledges, such as fuzzy mathematics,assessment theory, multi-attribute group decision theory and computer technology. The maincontents of this reasearch are as follows:(1) The theories of railway emergencies and railway emergency decision are discussed.The theories include definition, classification, grading, characteristics, and basic emergencyproperty of railway emergency, as well as the definitions, characteristics, processes, methodsof railway emergency decision.(2) Case-based reasoning (CBR) is applied to the railway emergency decision. Fourtuples of subject domain, problem domain, solution domain, and the effect domain are used todescribe railway emergency case. Attributes of the four tuples are presented. Framework ofrailway emergency is represented. Different attribute values including numeric, orderlyenumeration type, disorderly enumeration type, type of interval numbers,and fuzzy numbersare studied. A method of five attributes value type is proposed to calculate their similarity.Attribute weights of railway emergency are determined combing with attribute characteristicsby the analytic hierarchy process (AHP) method. Calculation method of local similarity andglobal similarity of the current case and the source case is studied. Calculation method ofglobal similarity is studied for values of attributes missing conditions, based on structuresimilarity algorithm.(3) Due to uncertainty and ambiguity of assessment value and knowledge incompletenessand preferences of evaluators in the aspects of railway emergency plans evaluation, four kindsof evaluation methods for railway emergency plan evaluation are presented. Aiming atlinguistic evaluation value of attribute, VIKOR method is improved for evaluting railwayemergency plan. Weights are solved by the method of subjective and objective weight basedon entropy. In addition, evaluation indexes of railway emergency plan is improved. In view of the evaluation indexes value is hybrid, a method based on2-tuple linguistic is presented forevaluating railway emergency plan with weight information known, and algorithm are given.Aiming at evaluation value of interval linguistic form, interval-valued2-tuple linguistichybrid average (IVTHA) operator and interval-valued2-tuple linguistic hybridgeometric(IVTHG) operator are defined. The method of multi-attribute group decisionmaking based on IVTHA operator is proposed for evaluating railway emergency plan, inaddition algorithm and steps are suggested. According to the evaluation indexes with differentpriorities and evaluation value of interval linguistic form,2-tuple prioritized weightedaverage(2TLPWA) operator,2-tuple prioritized weighted geometric(2TLPWG) operator,2-tuple prioritized ordered weighted average (2TLPOWA) operator, and2-tuple prioritizedordered weighted average(2TLPOWG) operator are suggested. The method of multi-attributegroup decision making based on2TLPOWA operator is presented, and algorithm is proposed.(4) Based on the theory of decision support system, the definition of the railwayemergency decision-making system, and the goal of the system are proposed. The frameworkof railway emergency decision system is built. The overall design of the railway emergencydecision system is presented. The detailed design of functional modules is made. In additionto knowledge base, model base, method base, and basic information database system aredesigned for the "library" system of the railway emergency decision system.In short, improving railway emergency decision-making methods and the level of railwayemergency decision-making has a certain practical significance. Combination study of CBRof artificial intelligence technology, the theory of multi-attribute group decision makingassessment and the technique of decision support system provides certain theoretical basis forrailway emergency decision-making.