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近年来新疆艾滋病发病率较高,预防控制工作严峻,此种情况下,基于2008年1月至2014年12月的艾滋病发病率数据,采用ARIMA方法及广义回归神经网络方法建立了ARIMA-GRNN组合预测模型,并用2015年1月至5月的数据检验模型预测能力,结果模型能较好地对新疆艾滋病发病率做预测,这可为新疆艾滋病的预防控制提供一定的科学参考. 相似文献
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本文利用美国艾滋病医疗试验机构ACTG的193A研究中的一组非平衡重复测量数据。以log(cd4+1)为体现疗效的因变量,年龄、性别为固定效应,治疗时间和滞后治疗时间为随机效应,同时考虑疗法对疗效的影响引入其与治疗时间的交互效应,建立线性混合效应模型。用SAS软件求解。再通过建立以治疗时间斜率随机效应为因变量初始logcd4为解释变量的回归模型判断艾滋病最佳治疗时机。结果表明,当初始cd4为185个/mm~3时治疗时机最佳,即为无症状感染的晚期.与美国DHHS推荐的小于200个/mm~3一致,却更为科学和精确。本研究对艾滋病治疗的临床实践具有重要的指导意义。 相似文献
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某市防疫站提供的实测统计资料表明病毒性肝炎的发病率是时间序列的一个现实{x_t},(见图1).一般要求预报流行高峰及近期发病率.人们极为关切流行高峰是否到来,和及时采取有效防疫措施的问题. 相似文献
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根据艾滋病在新疆的流行特点,建立了一个非线性动力系统的数学模型来研究艾滋病在新疆高危人群中传播的规律.通过查阅大量的统计数据和文献资料,确定了模型中部分参数的具体数值,然后通过数据拟合的方法得到了各个高危人群中的HIV病毒的传染性系数.在模型中,选择2004年底(2005年初)作为系统的初始点,预测了艾滋病未来几年内在新疆的流行趋势.最后,提出并比较遏止艾滋病传播的各项干预措施. 相似文献
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艾滋病是由人类免疫缺陷病毒(HIV)引起的一种免疫缺陷性疾病.HIV感染可以通过检测病毒的抗体、抗原、核酸或病毒培养来确定.目前,标准的检测方法是血清学HIV抗体检测,它是诊断艾滋病病毒感染者和艾滋病的主要指标和标准检测项目.问题1设A={受艾滋病病毒感染},B={检验反应为阳性 相似文献
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研究了具有桥梁人群(从事性服务的女性静脉吸毒者)的艾滋病模型.在桥梁人群内部建立一个DI模型.通过定性分析,证明了各类平衡点的稳定性,从而判断艾滋病流行与否. 相似文献
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人类免疫缺陷病毒(HIV)是一种严重威胁生命的病毒,感染艾滋病毒患者一般经历四个阶段:i)艾滋病毒阴性的窗口期(W);ii)阳性的无症状潜伏期(E);iii)有症状期(Ⅰ);以及iv)移除阶段(A).为深入研究艾滋病传播过程,建立SWEIA艾滋病毒传染模型,定义基本再生数,分析无病与地方病平衡点的存在性和局部稳定性,根据2004至2015年中国艾滋病患者数据,采用遗传算法对SWEIA模型中参数进行估计.通过对基本再生数敏感性分析以及模型数值随参数不同而产生的变化,揭示艾滋病窗口期的接触率是影响艾滋病流行的主要原因之一. 相似文献
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《数学的实践与认识》2020,(1)
迄今我国每年统计艾滋病的新增人数与死亡人数仍呈上升趋势,由于潜伏期长和初期无明显症状等原因,还存在大量未发现的HIV携带者,这给HIV的防控带来巨大挑战.旨在利用中国疾控中心网报数据和深圳市患者随访数据,结合传染病动力学和统计分析方法与临床知识,建立依微观CD4细胞计数划分的宏观HIV仓室数学模型,通过数值计算方法与MCMC参数估计方法实现稳健的参数拟合,进而利用不确定性和敏感性以及随机森林方法进行灵敏度分析.研究结果表明:2013年广东省未确诊HIV携带者约为13.1061万人,且该地区HIV疫情传播的基本再生数为2.8133.敏感性分析揭示艾滋病疫情防控最优方法是控制患者有效接触人数与沉默系数,由此建议制定针对控制艾滋病传播中一些现象的法律法规,在艾滋病高发地区实施清洁针具交换工作等,对疫情防控提出指导性建议. 相似文献
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结合某市的艾滋病现状给出了相应的传染病动力学模型,研究了其平衡点的稳定性,讨论了流行病的阈值,并对不同的说服率、不同的因病死亡率、不同的传染率分别进行了数值模拟,对该市艾滋病的预防和控制给出了理论上的指导和建议. 相似文献
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Ivan Kramer 《Mathematical and Computer Modelling》1992,16(12):55-60
The HIV incubation distribution curve leading to AIDS is derived from the hematic T-Helper cell density distribution for the seronegative population. After the HIV acute infection stage, the T-Helper cell density distribution curve is shown to begin uniformly translating towards zero density at the constant rate of 70.9 T-Cells/μL per year leading to AIDS. The future values of the HIV incubation period curve can now be credibly calculated, and it is projected that 90% of infecteds will develop AIDS 18 years after infection. HIV is postulated to lower the hematic T-Helper cell density equilibrium set-point to zero, causing the immune system to collapse. 相似文献
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基于亚洲艾滋病流行模型(Asian Epidemic Model,AEM)基本思想,建立我国艾滋病流行预测模型.利用该模型,估计某地1989—2007年艾滋病流行状况,同时设计不同行为改变方案,预测该地2008—2020年艾滋病流行趋势. 相似文献
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根据某市艾滋病出现的新特点,即外来人口对艾滋病的影响,给出了相应的传染病动力学模型,并进行了数值模拟. 相似文献
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This paper first provides a common framework for partial differential equation problems in both strong and weak form by rewriting
them as generalized interpolation problems. Then it is proven that any well-posed linear problem in strong or weak form can
be solved by certain meshless kernel methods to any prescribed accuracy.
The work described in this paper was partially supported by a grant from the Research Grants Council of the Hong Kong Special
Administrative Region, China (Project No. CityU 101205). Robert Schaback’s research in Hong Kong was sponsored by DFG and
City University of Hong Kong. 相似文献
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A nonlinear mathematical model is proposed and analyzed to study the effect of contact tracing on reducing the spread of HIV/AIDS in a homogeneous population with constant immigration of susceptibles. In modeling the dynamics, the population is divided into four subclasses of HIV negatives but susceptibles, HIV positives or infectives that do not know they are infected, HIV positives that know they are infected and that of AIDS patients. Susceptibles are assumed to become infected via sexual contacts with (both types of) infectives and all infectives move with constant rates to develop AIDS. The model is analyzed using the stability theory of differential equations and numerical simulation. The model analysis shows that contact tracing may be of immense help in reducing the spread of AIDS epidemic in a population. It is also found that the endemicity of infection is reduced when infectives after becoming aware of their infection do not take part in sexual interaction. 相似文献
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M.H. Ostadzad S. Shahmorad G.H. Erjaee 《Mathematical Methods in the Applied Sciences》2015,38(17):3601-3614
An Human Immunodeficiency Virus/Acquired Immuno‐Deficiency Syndrome (HIV/AIDS) epidemic model for sexual transmission with asymptomatic and symptomatic phase is proposed as a system of differential equations. The threshold and steady state for the model are determined and stabilities of disease free steady state is investigated. We use the model and study the effect of public health education on the spread of HIV/AIDS as a single‐strategy in HIV prevention. The education, including basic reproduction number for the model with public health education, is compared with the basic reproduction number for the HIV/AIDS in the absence of public health education. By comparing these two values, influence of public health education appears. According to property of , threshold proportion of educated adolescents, education rate for susceptible individuals and education efficacy is obtained. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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A nonlinear mathematical model is proposed to study the effect of tuberculosis on the spread of HIV infection in a logistically growing human population. The host population is divided into four sub classes of susceptibles, TB infectives, HIV infectives (with or without TB) and that of AIDS patients. The model exhibits four equilibria namely, a disease free, HIV free, TB free and an endemic equilibrium. The model has been studied qualitatively using stability theory of nonlinear differential equations and computer simulation. We have found a threshold parameter R0 which is if less than one, the disease free equilibrium is locally asymptotically stable otherwise for R0>1, at least one of the infections will be present in the population. It is shown that the positive endemic equilibrium is always locally stable but it may become globally stable under certain conditions showing that the disease becomes endemic. It is found that as the number of TB infectives decreases due to recovery, the number of HIV infectives also decreases and endemic equilibrium tends to TB free equilibrium. It is also observed that number of AIDS individuals decreases if TB is not associated with HIV infection. A numerical study of the model is also performed to investigate the influence of certain key parameters on the spread of the disease. 相似文献
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首次利用短期利率模型,分析香港银行同业拆借利率(Hibor),揭示了最近十年内香港银行同业拆借利率的基本特征.初步分析表明,Hibor数据的平稳性不能保证,因此采用了非参数统计方法.利用bandi文章中的方法,给出了函数的漂移项和扩散项的非参数估计,同时还得到了过程的局部时估计.通过实证分析,发现香港银行间同业拆借利率在2006至2015年间,以2009年为界,前后两个时间段的数据表现出不同的特征,样本数据的局部时函数也表现为双峰分布. 相似文献