Thermodynamic imaging calculation model on COVID-19 transmission and epidemic cities risk level assessment-data from Hubei in China.

Novel coronavirus pneumonia in 17 city (Hubei) provinces was analyzed by using the principle of thermodynamics. A thermodynamic imaging model of infectious diseases was established to calculate the cumulative superimposed density of epidemic in 17 cities (prefectures). An evaluation rule of urban risk grade is established and evaluates the COVID-19 risk of 17 cities. The results show that (1) the higher the superimposed density of urban epidemic, the more infected people. (2) In the incubation stage, the thermodynamic imaging shows a point distribution, random walk, and outward diffusion trend. In the initial stage, the color of thermodynamic imaging gradually deepened and the range gradually expanded. During the burst stage, the thermodynamic imaging color deepens rapidly and the scope expands rapidly. In the stable stage, the thermodynamic imaging color becomes darkest and the range is extended to the pole. (3) According to the situation of COVID-19 transmission in Hubei Province, the cumulative superimposed density of Wuhan epidemic is far more than 10,000, ranking as "highest-risk." Xiaogan and other 10 cities have a cumulative superimposed density within the range of [1000, 10,000], ranking as "high-risk." Shiyan and other 5 cities have accumulated superimposed density values within the range of [100, 1000], ranking as "medium-risk." Shennongjia cumulative superimposed density value is less than 100, and the level is "low-risk."

System Dynamics Models of Online Lending Platform Based on Vensim Simulation Technology and Analysis of Interest Rate Evolution Trend.

This paper mainly focuses on the construction of a system dynamics model of an online lending platform and the application of Vensim simulation technology in the analysis of the evolution trend of the investment interest rate. The system dynamics flow graph models of the investment subsystem, loan subsystem, and interest rate subsystem of the online lending platform were innovatively constructed; the level variable, flow rate variable, auxiliary variable, and mathematical relations between these variables as they relate to the platform were innovatively studied. Based on the key variables of the online lending platform, a system dynamics model of the online lending platform was innovatively constructed. The parameters were assigned using data from China's online lending industry, and the logical consistency, sensitivity, and validity of the simulation data of the system dynamics model were tested. Finally, we used Vensim simulation technology to simulate and analyze the impact of emergency scenarios on the interest rate evolution trend. Overall, this paper provides a scientific simulation technology and data analysis method for examining online lending platforms.

Risk assessment model and application of COVID-19 virus transmission in closed environments at sea.

This paper focuses on the risk assessment methods of novel coronavirus pneumonia virus (COVID-19) pneumonia virus spreading in closed marine environment. Firstly, the possibility of the spread of new coronavirus in closed environments at sea and the consequences of the harm caused by the epidemic are classified into five levels, and the corresponding risk assessment framework is constructed, and the risk assessment model of the spread of COVID-19 pneumonia virus in closed environment at sea is established taking the Japanese "Diamond Princess" as an example, the model is applied and its output is analysed. Finally, the proportion of the cumulative confirmed cases on the Diamond Princess is calculated, and the possibility of viral infection of Diamond Princess passengers in this COVID-19 pneumonia epidemic in four different risk transmission stages are assessed, and the corresponding risk assessment is undertaken. Through the calculation of risk assessment value, the five stages of the epidemic are established to assess the risk of the "Diamond Princess" outbreak. The research method in the present work helps to provide a risk assessment and analysis idea for the risk of spread of the COVID-19 epidemic in a closed environment at sea.

Environmental risk assessment and comprehensive index model of disaster loss for COVID-19 transmission.

This paper focuses on the study of environmental risk assessment and comprehensive index model of disaster loss for COVID-19 transmission. Considering the five environmental vectors of carrier vulnerability, environmental instability of pregnancy and disaster, intensity of disaster-causing factors, disaster prevention and mitigation capacity and emergency prevention and control capacity and its 38 indicators, the correlation coefficient matrix and principal component expressions of each vector are established by principal component analysis, respectively, and the index model of each vector is established on the basis. Then, considering the index models of these five vectors, we established the disaster loss composite index model, which was used to conduct environmental risk assessment and disaster loss composite index analysis of the transmission of COVID-19 in Hubei Province during the period of January 21, 2020 to March 18, 2020. The empirical study showed that: (1) the risk index peaked from January 21 to January 23; (2) the risk index was at a low but volatile level from January 24 to March 14; (3) the risk index rose again slightly from March 15 and rose to another peak on March 16. These fluctuating, smooth and fluctuating processes of the comprehensive index of disaster losses of COVID-19 in Hubei Province are basically stable and consistent with the actual situation of the virus outbreak in the early stage, isolation and prevention and control in the middle stage, and resumption of work and production in the late stage. The study in this paper provides a scientific decision-making reference for the prevention and control of COVID-19 as well as emergency prevention and control measures.