To enhance the efficiency of emergency logistics during the process of major public health risk governance, an efficient emergency logistics collaboration mechanism was designed based on the analysis of the behavioral characteristics of government and logistics enterprise. An evolutionary game model between local government and logistics enterprise was established to investigate the evolutional laws and paths of local government's supervision and logistics enterprise's collaboration. Then, the feasibility and effectiveness of the proposed model were verified based on the numerical simulation. The results indicate that the emergency logistics collaboration mechanism in major public health risk governance significantly depends on local government's supervision compared with the collaboration mechanism of commercial logistics and it makes the collaboration level of logistics enterprise fluctuate between 0.25 and 0.9 repeatedly. After the establishment of a dynamic reward and punishment mechanism for local government, the obtained collaboration level of logistics enterprise stabilizes at 0.46 when the number of games reaches 30. It can be seen that this dynamic reward and punishment mechanism improves the stability of emergency logistics collaboration mechanism significantly.

To improve the utilization of relief, reduce various losses and alleviate the suffering of survivors, how to use mathematical programming methods to optimize relief distribution strategy is a critical issue urgent to be solved currently. The current status of mathematical programming models for relief distribution was analyzed according to the criteria of objective quantity and intergovernmental relationships. An overview of the algorithms to solve the relief distribution optimization models was conducted. The future directions of the relief distribution optimization problem were summarized and pointed out. Research indicates that the establishment of the optimization support framework of relief distribution is necessary. And it is necessary that:the relief distribution optimization model is extended from single-objective programming to multiple-objective programming, the research viewpoint of relief distribution issue is changed from horizontal intergovernmental relationship to vertical one, the development from the certain condition based relief distribution optimization problem to the uncertain condition based one, the change from traditional relief distribution problem to the one with sustainable development idea, the design of solutions from using exact algorithm to using heuristic one, and applying new Information and Communications Technology (ICT) such as big data, digital twin and blockchain to develop relief distribution models.

To improve the utilization rate of human resource, reduce various losses caused by disasters, and contribute to the sustainable development, to apply efficient approaches to model the decisions of emergency organization is a critical and urgently-to-be-solved issue. Firstly, the concepts and connotations of disaster operations management and emergency organization were given. Secondly, the current states of the application and research of Semantic Bill of X (S-BOX), fractal theory, organizational theory, mathematical programming, evolutionary game theory, multi-agent simulation and other methods in emergency organization decision modeling were presented respectively. Finally, the potential research directions of emergency organization decision modeling were presented based on bi-level optimization theory, multi-swarm evolutionary game, big data, digital twin and blockchain technology.

In the process of traditional impact assessment of engineering change propagation for complex products,the joint effect of different association relationships among parts on change propagation is not comprehensively considered. Therefore,the multiplex network theory was applied to the modeling of complex product. Firstly,to explore the impact of different association relationships on engineering change propagation,the parts of a complex product and their functional, behavioral and structural association relationships were abstracted to a multiplex network. Then,the improved all-around distance index was used for evaluating the importance degrees of nodes in the multiplex network. Finally,the Susceptibility-Infection-Susceptibility(SIS)model was used to quantitatively assess the impact of engineering change propagation. To verify the effectiveness of the proposed method,the impact assessment of engineering change propagation of a type of diesel engine was taken as an example. Results demonstrate that:the multiplex network can fully describe complex products with different types of association relationships;the improved all-around distance index increases the ability to distinguish the importance degrees of nodes with the same coreness;the change in high-important parts will cause the avalanche propagation of engineering change throughout the product range.