Research on adaptive transmission and controls of COVID-19 on the basis of a complex network.

COVID-19 has caused massive disruption on the global economy and presents a considerable risk to human lives. Some countries have successfully controlled the pandemic by adopting strict measures, such as lockdown and travel restriction, but such methods are difficult to be applied widely due to their huge costs. To explore available and low-cost solutions, this study proposes an adaptive transmission model on the basis of a complex network, and gives control simulation method of COVID-19. The suggested model considers adaptive changes such as travel network and people's travel intention to form a three-level adaptive network transmission model among cities, communities, and people. The improved susceptible-exposed-infectious-recovered-dead transmission process is integrated into the network. Simulation experiments under high-, low-, and conventional-cost controls are performed. In these experiments, the travel restriction and closing cities are considered, and sensitivity analyses of the parameters are conducted to explore low-cost measures. Meanwhile, time duration and application conditions of different controls are discussed. Results show that lockdown is the most effective way, and the contact and infection rates are the two most important factors to control the pandemic. Low-cost combined control measures are feasible and effective for most countries. Finally, several suggestions are given for national and urban preventions and controls of COVID-19 and other infectious diseases in the future.

The module configuration optimization of vertical computer numerical control honing machine based on ideal outranking cardinal point.

To find the optimal one from all feasible module configuration schemes of high-end computer numerical control machine tools according to performance, cost, and delivery, this article studies the method of module configuration optimization. An ideal outranking cardinal point based on the module configuration optimization approach of vertical computer numerical control honing machine is proposed in this article. First, it establishes the multi-objective decision model of the module configuration optimization according to performance indicator function, cost indicator function, and delivery indicator function. Second, the feasible configuration schemes, which are obtained based on customer requirements, are transformed into the data matrix of decision attributes. Third, ideal outranking cardinal point is used to calculate the multi-objective decision model of the module configuration optimization. According to the comprehensive distance between the feasible configuration schemes and the ideal outranking cardinal point, and the inverse ideal outranking cardinal point, the optimal configuration scheme is selected. The feasibility and universality of the proposed approach is verified by a module configuration optimization case of vertical computer numerical control honing machine.