SARS传染模型的研究及实证分析

分析了SARS传染病的传播特点,建立了一个SARS传播的微分方程模型。利用最大似然估计法对模型中的参数进行了估计。利用网上的公开数据对模型进行了检验,所得结果与实际情况一致。此模型为传染病的预防和控制提供了理论依据。     

SARS epidemical forecast research in mathematical model

The SLJR model, simplified from the SEIJR model, is adopted to analyze the important parameters of the model of SARS epidemic such as the transmission rate, basic reproductive number. And some important parameters are obtained such as the transmission rate by applying this model to analyzing the situation in Hong Kong, Singapore and Canada at the outbreak of SARS. Then forecast of the transmission of SARS is drawn out here by the adjustment of parameters (such as quarantined rate) in the model. It is obvious that inflexion lies on the crunode of the graph, which indicates the big difference in transmission characteristics between the epidemic under control and not under control.This model can also be used in the comparison of the control effectiveness among different regions. The results from this model match well with the actual data in Hong Kong, Singapore and Canada and as a by-product, the index of the effectiveness of control in the later period can be acquired. It offers some quantitative indexes, which may help the further research in epidemic diseases.     

一类具时滞和扩散的传染病模型

研究了具时滞和扩散的SIR传染病模型,利用上下解及其迭代序列方法探讨在有界区域的半线性耦合抛物型方程组的渐近行为.结果表明,接触率小时问题的无病平衡点是全局渐近稳定的.     

Rationality of 17 cities'''' public perception of SARS and predictive model of psychological behavior

Generally speaking, humans are assumed to be rational when perceiving risky event, judging and adopting behavior, however, Herbert. Simon, the Nobel Laureate in economic science of 1987, claimed that humans havebounded rationality due to fundamental limitations in human mental processes, so they do not think rationally in real activities[1]; and the psychologist Kahnemen won the international recognition again in 2002 for having integrated insights from psychological research into economic sc…     

Rationality of 17 cities＇ public perception of SARS and predictive model of psychological behavior

This study investigated the feature of Chinese peoples?perception of SARS by surveying a stratified sample of 4231 people from 17 cities in China, and primarily pro-posed a risk perception centered predictive model of psy-chological behavior in crisis. The results indicated that, negative SARS-related information, especially informationof personal interest, will arouse peoples risk perception ofhigh level, and lead to irrational nervousness or scare; but positive SARS-related information, including recovery in-formation and that with measures taken by government, can decrease the level of risk perception. In the middle of May, people felt the highest level of risk on the SARS pathogens; the following are the physical health condition and infectiv-ity after recovering from SARS; they are factors that needspecial attention. SEM result analyses supported our hy-potheses in that SARS-related information affect people抯coping behavior and mental health through their riskperception, the four indices of risk assessment, feeling ofnerv- ousness, coping behavior and mental health areeffective presentimental indices for public psychological behavior in risky events.     

一类具扩散的两种群相互作用的传染病模型

针对具扩散的两种群相互作用的传染病模型,利用线性化方法及构造适当的Lyapunov泛函探讨在有界区域上的一类半线性耦合抛物型方程组的动力学行为.结果表明,只要易感食饵的内部竞争率足够小、染病率足够大,且染病食饵的死亡率足够小,捕食者对易感食饵的捕获率足够小,则正平衡点E*全局渐近稳定.     

SARS疫情与中国旅游业的可持续发展创新机制

SARS作为一种突发性的自然灾害，对中国旅游业产生了重大的影响．分析了2003年SARS疫情及其对中国旅游业的影响，并重点探讨了旅游业的敏感特征，提出了中国旅游业的可持续发展对策．     

SARS传播规律函数的ELMAN神经网络逼近方法

提出了用ELMAN神经网络逼近传染病传播规律函数的方法,给出了影响传染病传播的影响因素简单近似的量化途径。用北京市和山西省的统计数据来验证该方法,验证结果表明,训练后的ELMAN神经网络能较准确的逼近传染病的传播规律函数,该方法对传染病的预测和控制有一定意义。     

Modeling of epidemic spreading with white Gaussian noise

Motivated by the need to include the different characteristics of individuals and the damping effect in predictions of epidemic spreading, we build a model with variant coefficients and white Gaussian noise based on the traditional SIR model. The analytic and simulation results predicted by the model are presented and discussed. The simulations show that using the variant coefficients results in a higher percentage of susceptible individuals and a lower percentage of removed individuals. When the noise is included in the model, the percentage of infected individuals has a wider peak and more fluctuations than that predicted using the traditional SIR model.     

考虑车辆随机行为的交通流动力学模型

从研究微观个体车辆行为出发，考虑两种不同的具有不确定性的加速机制，提出了随机跟弛模型；在随机跟弛模型的基础上，得到了描述交通流宏观行为的连续性动力学方程，该方程是各项异性的，可以避免Daganzo提出的问题，对动力学方程的稳定性分析，得到稳定性判据。     

SARS预测模型及分析

充分考虑对SARS流行有较大影响的多个因素,建立了改进的微分方程模型.特别在模型中加入了反映政府控制措施的多个参数,并在SARS流行的控制前后等不同阶段发挥控制作用,使得模型的计算结果和实际数据吻合较好,有效地预测了SARS的流行趋势,并给出了控制措施及建议.     

The outbreak pattern of the SARS cases in Asia

The severe acute respiratory syndrome (SARS) caused tremendous damage to many Asia countries, especially China. The transmission process and outbreak pattern of SARS is still not well understood. This study aims to find a simple model to describe the outbreak pattern of SARS cases by using SARS case data commonly released by governments. The outbreak pattern of cumulative SARS cases is expected to be a logistic type because the infection will be slowed down due to the increasing control effort by people and/or due to depletion of susceptible individuals. The increase rate of SARS cases is expected to decrease with the cumulative SARS cases, as described by the traditional logistical model, which is widely used in population dynamic studies. The instantaneous rate of increases were significantly and negatively correlated with the cumulative SARS cases in mainland of China (including Beijing, Hebei, Tianjin, Shanxi,the Autonomous Region of Inner Mongolia) and Singapore. The basic reproduction number R0 in Asia ranged from 2.0 to 5.6 (except for Taiwan, China). The R0 of Hebei and Tianjin were much higher than that of Singapore, Hongkong, Beijing, Shanxi, Inner Mongolia, indicating SARS virus might have originated differently or new mutations occurred during transmission. We demonstrated that the outbreaks of SARS in many regions of Asia were wall described by the logistic model, and the control measures implemented by governments are effective. The maximum instantaneous rate of increase, basic reproductive number, and maximum cumulative SARS cases were also calculated by using the logistic model.     

矿区环境系统动力学仿真模型的建立

以研究复杂问题和复杂系统的有效工具——系统动力学为手段，把矿区环境系统分成固体废物、水和大气三部分，建立了矿区环境系统动力学仿真模型。并以某矿区为例进行了历史检验和动态仿真与预测。研究表明，所建立的模型是有效的和可信的，能够充分代表现实的矿区环境系统。该模型还具有一定的通用性和可移植性。     

Reovirus, isolated from SARS patients

Beijing has been severely affected by SARS, and SARS-associated coronavirus has been confirmed as its cause. However, clinical and experimental evidence implicates the possibility of co-infection. In this report, reovirus was isolated from throat swabs of SARS patients, including the first case in Beijing and her mother. Identification with the electron microscopy revealed the characteristic features of reovirus. 24 of 38 samples from other SARS cases were found to have serologic responses to the reovirus. Primers designed for reovirus have amplified several fragments of DNA, one of which was sequenced (S2 gene fragment), which indicates it as a unique reovirus (orthoreovirus). Preliminary animal experiment showed that inoculation of the reovirus in mice caused death with atypical pneumonia. Nevertheless, the association of reovirus with SARS outbreak requires to be further investigated.     

在抗击非典中发扬伟大的民族精神

新的时代呼唤着民族精神，新的实践孕育和催生着民族精神。在抗击非典的斗争中突出表现出来的这些方面，既传承着中华民族几千年的传统精神，也展示出21世纪新时代的特点和风采，丰富和发展着我们的民族精神，成为我们建设中国特色社会主义与共同创造幸福生活和美好未来的宝贵精神财富。     

SARS的研究进展

2003年3月,发现SARS病原是一种从未在人类或动物中发现过的新的冠状病毒.其基因组结构与其他的冠状病毒相似,由29727核苷酸组成,有11个开放阅读框.通过多基因分析序列比较说明,SARS冠状病毒与已知的冠状病毒无关.针对SARS冠状病毒的各种特征及研究进展进行了综述.     

北京市SARS数学模型的建立与拟合

SARS对中国社会的发展产生了重大影响，本人经典的SIR模型为理论基础，以2003年4月21日至6月23日有关SARS的数据为参考资料，着重从教学的角度对SARS疫情进行了分析和拟合。结果表明，SIR模型能近似地描述SARS疫情的发展和变化。     

现行建筑空调系统预防SARS的要点和措施

简要介绍了空调系统的形式、常用设备，提出了空调系统预防SARS的要点及措施。     

分布式系统中动态负载均衡实现模型

随着计算机技术的发展,分布式系统日益受到人们的重视因而被普遍应用,但由于任务提出和执行的随机性,各台机器上负载不均衡现象时有发生,所以负载均衡是提高分布式系统效率的重要因素,但目前的研究都集中在策略的提出上,对实现模型的研究比较少.作者在综合许多负载均衡策略的基础上按照性能递增的顺序,结合网络拓扑结构构建了链式模型、网状模型和链网模型,对其进行了系统的研究,对几种模型给出了各自相应的算法,并进行了评价,指出了这几种模型各自的优缺点及适用范围.研究结果表明链网模型在动态负载均衡实现方面具有良好的有效性、稳定性、可靠性、通用性,对用户具有透明性,是一种性能优越的动态负载均衡模型.     

Hodgkin-Huxley神经元系统的随机动力学研究

真实的神经元是处在一个充满噪声的复杂生物环境之中．这些内噪声对单个神经元动作电位发放的影响是当前热点之一．针对神经生物学中的Hodgkin—Huxley方程描述这一经典的理论模型，将其转化为随机微分方程形式，利用随机路径分析方法探讨了内噪声对神经元动作电位发放动力学过程的作用．理论结果表明，内噪声存在时动作电位的发放形式偏离无噪声时的概率很小．初步认为内噪声对动作电位发放过程的影响可以忽略，即神经元系统动作电位发放的动力学机制自身存在内禀的鲁棒性。