Grey Three-way Decision-making Method And Its Application

Decision-making problems exist widely in social life.Three-way decision-making is an effective decision-making method that conforms to the characteristics of human cognition.Its core idea is to divide the domain of discourse into three disjoint regions,and make corresponding decision-making strategies of accepting,delaying,and rejecting.Because three-way decision-making method can fully consider the uncertain factors in the decision-making process,it has a high tolerance for decision-making mistakes.It has become a popular decision-making method.Research on the three-way decision has obtained many results.With the development of society,both the complexity of the decision-making environment and the speed of change are increasing.The rapidly changing environment brings great uncertainty to decision-making.Describing the uncertainty of the decision-making system with grey information and studying how to solve the three-way decision-making problem under the static or dynamic grey information system is very helpful for decision makers.Therefore,in this thesis,grey numbers are used to represent uncertain information,and three-way decision-making models are constructed by using the relevant methods of grey theory,and three-way decision-making method under different dynamic environments are discussed.Specifically,the following research work has been carried out:(1)A static grey three-way decision-making method is constructed.This thesis mainly studies two core problems of three-way decision-making,which are conditional probability calculation and decision threshold calculation.Firstly,based on the grey characteristics of attribute information,the attribute information is represented by the interval grey numbers.By calculating the grey incidence degree,the universe is divided based on the grey similarity relationship.Then,the delay cost coefficient is introduced to construct a relative loss function based on grey numbers.On this basis,the comprehensive decision threshold is calculated and the decision rules are extracted.Finally,the model is verified by a numerical case.The novel grey three-way decision-making model can deal with the decision-making problem with attribute information and loss function as grey numbers,which further enriches the theoretical research of three-way decision-making.(2)A dynamic grey three-way decision-making method is constructed.The dynamic decision-making environment manifests itself on many levels.From the view of time,there are dynamic attribute value and dynamic decision object.From the view of global information updates,dynamic decision information system can be classified as two kinds: one is considering multi-stage state and the other is considering information change trends.Based on the grey target decision-making method,this thesis discusses the grey three-way decision-making problem in different situations and constructs corresponding grey dynamic three-way decision-making model.(3)Apply the dynamic three-way decision-making method to solve the decision-making problems related to recommendation system.According to the changes in the dynamic information system,this thesis constructs a dynamic three-way decision-making model to solve the problem of film recommendation.This model can effectively improve the flexibility of the film arrangement decision.It not only proves the practicability of the model,but also enriches the application level of three-way decision-making.The semantic interpretation of decision rules provides an effective solution for dealing with recommender system problems.