ABSTRACT
Since December 2019, the outbreak of COVID-19 in Wuhan has spread rapidly due to population movement during the Spring Festival holidays. Since January 23rd, 2020, the strategies of containment and contact tracing followed by quarantine and isolation has been implemented extensively in mainland China, and the rates of detection and confirmation have been continuously increased, which have effectively suppressed the rapid spread of the epidemic. In the early stage of the outbreak of COVID-19, it is of great practical significance to analyze the transmission risk of the epidemic and evaluate the effectiveness and timeliness of prevention and control strategies by using mathematical models and combining with a small amount of real-time updated multi-source data. On the basis of our previous research, we systematically introduce how to establish the transmission dynamic models in line with current Chinese prevention and control strategies step by step, according to the different epidemic stages and the improvement of the data. By summarized our modelling and assessing ideas, the model formulations vary from autonomous to non-autonomous dynamic systems, the risk assessment index changes from the basic regeneration number to the effective regeneration number, and the epidemic development and assessment evolve from the early SEIHR transmission model-based dynamics to the recent dynamics which are mainly associated with the variation of the isolated and suspected population sizes.
ABSTRACT
Objective To quantitatively analyze the epidemic situation of tuberculosis(TB)by modeling the data of tuberculosis in prefectures of Xinjiang,and predict the new cases of tuberculosis in prefectures of Xinjiang.Methods A dynamic model was used to fit the data of TB in 14 prefectures in Xinjiang from 2005 to 2014,the results of the fitting were verified by tuberculosis data in 2015－2017,verified results were evaluated,estimated values and basic reproductive numbers (R0)of parameters in each region were obtained,data of new TB in 2018－2022 were predic-ted.Results The verification of TB data in 2015－2017 showed that the actual values fell within the 95% confidence interval of the predictive value curve,model was fit well.R0in Southern Kashgar was 1 1.38 (95%CI:1 1.33－11.50),R0in Urumqi City in Eastern Xinjiang and Ili Kazak Autonomous Prefecture in Northern Xinjiang were 5.46 (95% CI :5.28－5.50)and 2.22 (95% CI :2.18－2.28)respectively.The epidemic situation of TB in Southern Xinjiang was more serious than that in Northern and Eastern Xinjiang,epidemic situation of TB in Kash- gar Prefecture was most serious.The predicted results showed that the number of new TB from 2018 to 2022 will slowly grow in most prefectures.Conclusion The dynamical model of TB fits well and is feasible in this study,it can be used for prediction of new TB cases,intervention and management in Southern Xinjiang should be strength-ened to control the prevalence of TB.
ABSTRACT
The establishment and realization of the VPP calucation's model for the functional analytic theory are discussed in this paper. Functional analyzing method is a theoretical model of the VPP calculation which can eliminate the influence of the sail and board's size skillfully, so it can be regarded as a brief standard of the sailboard's VPP results. As a brief watery dynamical model, resistance on board can be regarded as a direct proportion to the square of the boat-velocity. The boat-velocities at the state of six wind-velocities (3 m/s-8 m/s) with angles of 25°-180° are obtained by calculating, which provides an important gist of the sailing-route's selection in upwind-sailing.
ABSTRACT
The establishment and realization of the VPP calucation's model for the functional analytic theory are discussed in this paper. Functional analyzing method is a theoretical model of the VPP calculation which can eliminate the influence of the sail and board's size skillfully, so it can be regarded as a brief standard of the sailboard's VPP results. As a brief watery dynamical model, resistance on board can be regarded as a direct proportion to the square of the boat-velocity. The boat-velocities at the state of six wind-velocities (3 m/s-8 m/s) with angles of 25°-180° are obtained by calculating, which provides an important gist of the sailing-route's selection in upwind-sailing.