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学者姓名：魏凤英
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Abstract ：
This work develops a novel approximation for a class of superlinear stochastic Kol-mogorov equations with positive global solutions. On the one hand, most existing explicit methods that work for the superlinear stochastic differential equations (SDEs), e.g. various modified Euler-Maruyama (EM) methods, fail to preserve positivity of the solution. On the other hand, methods that preserve positivity are mostly implicit, or fail to cope with the multi-dimensional scenario. This work aims to construct an advanced numerical method which is not only naturally structure preserving but also cost effective. A strong convergence framework is then developed with an almost optimal convergence rate of order arbitrarily close to 1/2. To make the arguments concise, we elaborate our theory with the generalised stochastic Lotka-Volterra model, though the method is applicable to a wide bunch of multi-dimensional superlinear stochastic Kolmogorov systems in various fields including finance and epidemiology.& COPY; 2023 Published by Elsevier B.V.
Keyword ：
Convergence rate Convergence rate Exponential Euler-Maruyama method Exponential Euler-Maruyama method Kolmogorov equation Kolmogorov equation Stochastic differential equation Stochastic differential equation Structure preserving numerical method Structure preserving numerical method
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| GB/T 7714 | Cai, Yongmei , Mao, Xuerong , Wei, Fengying . An advanced numerical scheme for multi-dimensional stochastic Kolmogorov equations with superlinear coefficients [J]. | JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS , 2024 , 437 . |
| MLA | Cai, Yongmei 等. "An advanced numerical scheme for multi-dimensional stochastic Kolmogorov equations with superlinear coefficients" . | JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 437 (2024) . |
| APA | Cai, Yongmei , Mao, Xuerong , Wei, Fengying . An advanced numerical scheme for multi-dimensional stochastic Kolmogorov equations with superlinear coefficients . | JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS , 2024 , 437 . |
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In this study, we proposed two, symptom-dependent, HIV/AIDS models to investigate the dynamical properties of HIV/AIDS in the Fujian Province. The basic reproduction number was obtained, and the local and global stabilities of the disease-free and endemic equilibrium points were verified to the deterministic HIV/AIDS model. Moreover, the indicators R0s and Re0 were derived for the stochastic HIV/AIDS model, and the conditions for stationary distribution and stochastic extinction were investigated. By using the surveillance data from the Fujian Provincial Center for Disease Control and Prevention, some numerical simulations and future predictions on the scale of HIV/AIDS infections in the Fujian Province were conducted. © 2024 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License.
Keyword ：
Cell proliferation Cell proliferation Disease control Disease control Diseases Diseases Stochastic models Stochastic models Stochastic systems Stochastic systems Transmissions Transmissions
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| GB/T 7714 | Li, Wenshuang , Cai, Shaojian , Zhai, Xuanpei et al. Transmission dynamics of symptom-dependent HIV/AIDS models [J]. | Mathematical Biosciences and Engineering , 2024 , 21 (2) : 1819-1843 . |
| MLA | Li, Wenshuang et al. "Transmission dynamics of symptom-dependent HIV/AIDS models" . | Mathematical Biosciences and Engineering 21 . 2 (2024) : 1819-1843 . |
| APA | Li, Wenshuang , Cai, Shaojian , Zhai, Xuanpei , Ou, Jianming , Zheng, Kuicheng , Wei, Fengying et al. Transmission dynamics of symptom-dependent HIV/AIDS models . | Mathematical Biosciences and Engineering , 2024 , 21 (2) , 1819-1843 . |
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Background: The structure of age groups and social contacts of the total population influenced infection scales and hospital-bed requirements, especially influenced severe infections and deaths during the global prevalence of COVID-19. Before the end of the year 2022, Chinese government implemented the national vaccination and had built the herd immunity cross the country, and announced Twenty Measures (November 11) and Ten New Measures (December 7) for further modifications of dynamic zero-COVID polity on the Chinese mainland. With the nation-wide vaccination and modified measures background, Fuzhou COVID-19 large wave (November 19, 2022–February 9, 2023) led by Omicron BA.5.2 variant was recorded and prevailed for three months in Fujian Province. Methods: A multi-age groups susceptible-exposed-infected-hospitalized-recovered (SEIHR) COVID-19 model with social contacts was proposed in this study. The main object was to evaluate the impacts of age groups and social contacts of the total population. The idea of Least Squares method was governed to perform the data fittings of four age groups against the surveillance data from Fujian Provincial Center for Disease Control and Prevention (Fujian CDC). The next generation matrix method was used to compute basic reproduction number for the total population and for the specific age group. The tendencies of effective reproduction number of four age groups were plotted by using the Epiestim R package and the SEIHR model for in-depth discussions. The sensitivity analysis by using sensitivity index and partial rank correlation coefficients values (PRCC values) were operated to reveal the differences of age groups against the main parameters. Results: The main epidemiological features such as basic reproduction number, effective reproduction number and sensitivity analysis were extensively discussed for multi-age groups SEIHR model in this study. Firstly, by using of the next generation matrix method, basic reproduction number R0 of the total population was estimated as 1.57 using parameter values of four age groups of Fuzhou COVID-19 large wave. Given age group k, the values of R0k (age group k to age group k), the values of R0k (an infected of age group k to the total population) and the values of R^0k (an infected of the total population to age group k) were also estimated, in which the explorations of the impacts of age groups revealed that the relationship R0k>R0k>R^0k was valid. Then, the fluctuating tendencies of effective reproduction number Rt were demonstrated by using two approaches (the surveillance data and the SEIHR model) for Fuzhou COVID-19 large wave, during which high-risk group (G4 group) mainly contributed the infection scale due to high susceptibility to infection and high risks to basic diseases. Further, the sensitivity analysis using two approaches (the sensitivity index and the PRCC values) revealed that susceptibility to infection of age groups played the vital roles, while the numerical simulation showed that infection scale varied with the changes of social contacts of age groups. The results of this study claimed that the high-risk group out of the total population was concerned by the local government with the highest susceptibility to infection against COVID-19. Conclusions: This study verified that the partition structure of age groups of the total population, the susceptibility to infection of age groups, the social contacts among age groups were the important contributors of infection scale. The less social contacts and adequate hospital beds for high-risk group were profitable to control the spread of COVID-19. To avoid the emergence of medical runs against new variant in the future, the policymakers from local government were suggested to decline social contacts when hospital beds were limited. © 2024 The Authors
Keyword ：
Age group Age group Contact matrix Contact matrix COVID-19 model COVID-19 model Omicron BA.5.2 variant Omicron BA.5.2 variant Social contact Social contact
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| GB/T 7714 | Lan, X. , Chen, G. , Zhou, R. et al. An SEIHR model with age group and social contact for analysis of Fuzhou COVID-19 large wave [J]. | Infectious Disease Modelling , 2024 , 9 (3) : 728-743 . |
| MLA | Lan, X. et al. "An SEIHR model with age group and social contact for analysis of Fuzhou COVID-19 large wave" . | Infectious Disease Modelling 9 . 3 (2024) : 728-743 . |
| APA | Lan, X. , Chen, G. , Zhou, R. , Zheng, K. , Cai, S. , Wei, F. et al. An SEIHR model with age group and social contact for analysis of Fuzhou COVID-19 large wave . | Infectious Disease Modelling , 2024 , 9 (3) , 728-743 . |
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The complex interactions were performed among non-pharmaceutical interventions, vaccinations, and hosts for all epidemics in mainland China during the spread of COVID-19. Specially, the small-scale epidemic in the city described by SVEIR model was less found in the current studies. The SVEIR model with control was established to analyze the dynamical and epidemiological features of two epidemics in Jinzhou City led by Omicron variants before and after Twenty Measures. In this study, the total population (N) of Jinzhou City was divided into five compartments: the susceptible (S), the vaccinated (V), the exposed (E), the infected (I), and the recovered (R). By surveillance data and the SVEIR model, three methods (maximum likelihood method, exponential growth rate method, next generation matrix method) were governed to estimate basic reproduction number, and the results showed that an increasing tendency of basic reproduction number from Omicron BA.5.2 to Omicron BA.2.12.1. Meanwhile, the effective reproduction number for two epidemics were investigated by surveillance data, and the results showed that Jinzhou wave 1 reached the peak on November 1 and was controlled 7 days later, and that Jinzhou wave 2 reached the peak on November 28 and was controlled 5 days later. Moreover, the impacts of non-pharmaceutical interventions (awareness delay, peak delay, control intensity) were discussed extensively, the variations of infection scales for Omicron variant and EG.5 variant were also discussed. Furthermore, the investigations on peaks and infection scales for two epidemics in dynamic zero-COVID policy were operated by the SVEIR model with control. The investigations on public medical requirements of Jinzhou City and Liaoning Province were analyzed by using SVEIR model without control, which provided a possible perspective on variant evolution in the future. (c) 2024 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keyword ：
Control strategy Control strategy COVID-19 COVID-19 SVEIR model SVEIR model Twenty measures Twenty measures Variant evolution Variant evolution
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| GB/T 7714 | Chen, Kaijing , Wei, Fengying , Zhang, Xinyan et al. Epidemiological feature analysis of SVEIR model with control strategy and variant evolution [J]. | INFECTIOUS DISEASE MODELLING , 2024 , 9 (3) : 689-700 . |
| MLA | Chen, Kaijing et al. "Epidemiological feature analysis of SVEIR model with control strategy and variant evolution" . | INFECTIOUS DISEASE MODELLING 9 . 3 (2024) : 689-700 . |
| APA | Chen, Kaijing , Wei, Fengying , Zhang, Xinyan , Jin, Hao , Wang, Zuwen , Zuo, Yue et al. Epidemiological feature analysis of SVEIR model with control strategy and variant evolution . | INFECTIOUS DISEASE MODELLING , 2024 , 9 (3) , 689-700 . |
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The epidemiological characteristics and distributions of two epidemics in Fujian Province of Southeast China were attributed to the complex interactions among variant, host, and non-pharmaceutical interventions (NPIs). All reported cases in the Putian epidemic (September 8–October 2, 2021, Delta variant B.1.617.2) and Fuzhou epidemic (October 22–November 18, 2022, Omicron variant BA.5.2) were classified by sex, age group, occupation, and location in this study. Using surveillance data from the Fujian Provincial Center for Disease Control and Prevention, we established a virus-oriented SVEIR (Susceptible–Vaccinated–Exposed–Infected–Recovered) model to investigate the dynamic evolution features of these two variants and the effects of NPIs. The optimal simulations were carried out with variants and scenario investigations. The scenario investigations showed that NPIs significantly reduced the transmission risk and infection scales of COVID-19, and that the Omicron variant was more infectious than the Delta variant. Moreover, the dynamic investigations revealed the increasing tendencies from Delta to Omicron, such as the basic reproduction number, infection rate, percentage of high-risk cases, and the growth rate. Decreasing tendencies were also identified, such as the average recovery period, the awareness delay, and the percentage of symptomatic cases. This study highlighted that NPIs played critical roles in successfully containing the two epidemics. Such interventions are strongly recommended to public health policymakers. © 2024
Keyword ：
COVID-19 COVID-19 Delta variant Delta variant Non-pharmaceutical interventions Non-pharmaceutical interventions Omicron variant Omicron variant SVEIR model SVEIR model Transmission dynamics Transmission dynamics
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| GB/T 7714 | Zhou, R. , Cai, S. , Chen, G. et al. Dynamic evolution of an SVEIR model with variants and non-pharmaceutical interventions for controlling COVID-19 [J]. | Journal of Biosafety and Biosecurity , 2024 , 6 (2) : 67-75 . |
| MLA | Zhou, R. et al. "Dynamic evolution of an SVEIR model with variants and non-pharmaceutical interventions for controlling COVID-19" . | Journal of Biosafety and Biosecurity 6 . 2 (2024) : 67-75 . |
| APA | Zhou, R. , Cai, S. , Chen, G. , Huang, S. , Jin, Z. , Peng, Z. et al. Dynamic evolution of an SVEIR model with variants and non-pharmaceutical interventions for controlling COVID-19 . | Journal of Biosafety and Biosecurity , 2024 , 6 (2) , 67-75 . |
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The prediction system EpiSIX was used to study the COVID-19 epidemic in mainland China between November 2022 and January 2023, based on reported data from December 9, 2022, to January 30, 2023, released by The Chinese Center for Disease Control and Prevention on February 1, 2023. Three kinds of reported data were used for model fitting: the daily numbers of positive nucleic acid tests and deaths, and the daily number of hospital beds taken by COVID-19 patients. It was estimated that the overall infection rate was 87.54% and the overall case fatality rate was 0.078%–0.116% (median 0.100%). Assuming that a new COVID-19 epidemic outbreak would start in March or April of 2023, induced by a slightly more infectious mutant strain, we predicted a possible large rebound between September and October 2023, with a peak demand of between 800,000 and 900,000 inpatient beds. If no such new outbreak was induced by other variants, then the current COVID-19 epidemic course in mainland China would remain under control until the end of 2023. However, it is suggested that the necessary medical resources be prepared to manage possible COVID-19 epidemic emergencies in the near future, especially for the period between September and October 2023. © 2023
Keyword ：
Case fatality rate Case fatality rate COVID-19 COVID-19 Epidemic Epidemic Infection rate Infection rate Prediction Prediction
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| GB/T 7714 | Bai, Y. , Peng, Z. , Wei, F. et al. Study on the COVID-19 epidemic in mainland China between November 2022 and January 2023, with prediction of its tendency [J]. | Journal of Biosafety and Biosecurity , 2023 , 5 (1) : 39-44 . |
| MLA | Bai, Y. et al. "Study on the COVID-19 epidemic in mainland China between November 2022 and January 2023, with prediction of its tendency" . | Journal of Biosafety and Biosecurity 5 . 1 (2023) : 39-44 . |
| APA | Bai, Y. , Peng, Z. , Wei, F. , Jin, Z. , Wang, J. , Xu, X. et al. Study on the COVID-19 epidemic in mainland China between November 2022 and January 2023, with prediction of its tendency . | Journal of Biosafety and Biosecurity , 2023 , 5 (1) , 39-44 . |
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Since its emergence, SARS-CoV-2 virus, the causative agent of COVID-19, has undergone over three years of evolutionary changes. Throughout this evolutionary process, multiple variants, such as Alpha, Beta, Gamma, Delta, and Omicron, have emerged, leading to widespread outbreaks and pandemics. A comprehensive analysis of the evolution of SARS-CoV-2 over the past three years reveals its progression through three distinct stages. © 2023
Keyword ：
COVID-19 COVID-19 multi-lineage evolution multi-lineage evolution SARS-CoV-2 SARS-CoV-2
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| GB/T 7714 | Sun, Y. , Wang, M. , Wei, F. et al. COVID's future: Viral multi-lineage evolution and the dynamics of small epidemic waves without seasonality in COVID-19 [J]. | Journal of Biosafety and Biosecurity , 2023 , 5 (3) : 96-99 . |
| MLA | Sun, Y. et al. "COVID's future: Viral multi-lineage evolution and the dynamics of small epidemic waves without seasonality in COVID-19" . | Journal of Biosafety and Biosecurity 5 . 3 (2023) : 96-99 . |
| APA | Sun, Y. , Wang, M. , Wei, F. , Huang, S. , Xu, J. . COVID's future: Viral multi-lineage evolution and the dynamics of small epidemic waves without seasonality in COVID-19 . | Journal of Biosafety and Biosecurity , 2023 , 5 (3) , 96-99 . |
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We establish a stochastic HIV/AIDS model involving the susceptible with protection awareness within a total population. The mechanism of dynamic behaviors of the stochastic HIV/AIDS model with protection awareness are investigated in order to control the spread of HIV/AIDS. We firstly show that the stochastic model admits a global positive solution with any initial positive values. By constructing Lyapunov functions, the ergodic stationary distribution under the condition symbolscript > symbolscript and the extinction under the condition symbolscript < symbolscript for the stochastic model are further obtained respectively. Moreover, by using positive preserving truncated Euler-Maruyama method (PPTEM), the related numerical simulations are performed, which demonstrate the quantitative properties of persistence and extinction of the solution. Precisely, the increasing of protection efficiency of the susceptible with protection awareness reduces the scale of the infected individuals with AIDS; and the continuous antiretroviral therapy (ART) also benefits the control of the scale of the infected individuals with HIV/AIDS; the media reports with more instructions and details such as taking post-exposure prophylaxis (PEP) within 72 h to help the individuals avoid the infection to meet the 90%-90%-90% plan of WHO.
Keyword ：
AIDS infection AIDS infection Extinction Extinction HIV HIV Protection awareness Protection awareness Stationary distribution Stationary distribution
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| GB/T 7714 | Zhai, Xuanpei , Li, Wenshuang , Wei, Fengying et al. Dynamics of an HIV/AIDS transmission model with protection awareness and fluctuations [J]. | CHAOS SOLITONS & FRACTALS , 2023 , 169 . |
| MLA | Zhai, Xuanpei et al. "Dynamics of an HIV/AIDS transmission model with protection awareness and fluctuations" . | CHAOS SOLITONS & FRACTALS 169 (2023) . |
| APA | Zhai, Xuanpei , Li, Wenshuang , Wei, Fengying , Mao, Xuerong . Dynamics of an HIV/AIDS transmission model with protection awareness and fluctuations . | CHAOS SOLITONS & FRACTALS , 2023 , 169 . |
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本文研究在马尔科夫状态下具有Beddington-DeAngeis功能反应发生率的SVIR传染病模型的动力学问题.首先,得到系统具有唯一的全局正解;然后,通过构造恰当的李雅普诺夫函数得到:当Rs0＞1时,系统存在平稳分布;当Re0＜1时,疾病将会指数灭绝;最后通过数值模拟对本文主要理论的可行性进行验证.
Keyword ：
传染病 传染病 平稳分布 平稳分布 疫苗 疫苗 绝灭性 绝灭性 马尔科夫切换 马尔科夫切换
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| GB/T 7714 | 李丹 , 魏凤英 . 具有马尔科夫切换的SVIR传染病模型的动力学 [J]. | 应用数学 , 2023 , 36 (3) : 684-693 . |
| MLA | 李丹 et al. "具有马尔科夫切换的SVIR传染病模型的动力学" . | 应用数学 36 . 3 (2023) : 684-693 . |
| APA | 李丹 , 魏凤英 . 具有马尔科夫切换的SVIR传染病模型的动力学 . | 应用数学 , 2023 , 36 (3) , 684-693 . |
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We study a switching heroin epidemic model in this paper, in which the switching of supply of heroin occurs due to the flowering period and fruiting period of opium poppy plants. Precisely, we give three equations to represent the dynamics of the susceptible, the dynamics of the untreated drug addicts and the dynamics of the drug addicts under treatment, respectively, within a local population, and the coefficients of each equation are functions of Markov chains taking values in a finite state space. The first concern is to prove the existence and uniqueness of a global positive solution to the switching model. Then, the survival dynamics including the extinction and persistence of the untreated drug addicts under some moderate conditions are derived. The corresponding numerical simulations reveal that the densities of sample paths depend on regime switching, and larger intensities of the white noises yield earlier times for extinction of the untreated drug addicts. Especially, when the switching model degenerates to the constant model, we show the existence of the positive equilibrium point under moderate conditions, and we give the expression of the probability density function around the positive equilibrium point.
Keyword ：
extinction extinction Fokker-Planck equation Fokker-Planck equation heroin model heroin model probability density function probability density function regime switching regime switching stationary distribution stationary distribution
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| GB/T 7714 | Jiang, Hui , Chen, Ling , Wei, Fengying et al. Survival analysis and probability density function of switching heroin model [J]. | MATHEMATICAL BIOSCIENCES AND ENGINEERING , 2023 , 20 (7) : 13222-13249 . |
| MLA | Jiang, Hui et al. "Survival analysis and probability density function of switching heroin model" . | MATHEMATICAL BIOSCIENCES AND ENGINEERING 20 . 7 (2023) : 13222-13249 . |
| APA | Jiang, Hui , Chen, Ling , Wei, Fengying , Zhu, Quanxin . Survival analysis and probability density function of switching heroin model . | MATHEMATICAL BIOSCIENCES AND ENGINEERING , 2023 , 20 (7) , 13222-13249 . |
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