平教会定县实验中的农村卫生工作之考察

中华平民教育促进会定县实验区在二十世纪三十年代创立了一套由村保健员、乡保健所、县保健院组成的三级卫生保健网,并在学校卫生、妇婴保健、传染病预防和疾病治疗等方面做出了显著的成绩,在当时产生了广泛的影响,对我们今天来说仍值得借鉴。     

试论19世纪60年代～70年代东疆地区封禁政策的危机--兼谈"移民实边"思想的产生

19世纪60年代～70年代东疆地区封禁政策的危机,主要表现在沙俄的军事侵略威胁、朝鲜流民问题的冲击、东北边疆防御力量的空前削弱三个方面。清廷为了摆脱这一危机而苦苦摸索,移民实边思想便是这一摸索的产物。     

《史记》与《淮南子》

《淮南子》是汉代黄老道家著作，它对《史记》的影响主 要在思想方面。《淮南子》在构建天人古今知识体系、对待先秦诸子的思想方法、倡导法与 时变、礼与俗化、主张审微、重时等一系列问题上，给《史记》以深刻启示。《淮南子·天 文训》与《史记·天官书》之间也存在着学术联系。     

科学执政、民主执政中的依法执政基本途径

依法执政或依法行政,作为执政方式最为直接、最为具体的基本实践环节或途径,在相当范围内反映着科学执政、民主执政的实现程度。这取决于《行政许可法》不打折扣地坚决实施,政府的依法执政职能方式从重管制向重服务转变;职能范围从“全能”向“有限”回归;职能性质由“专断”走向真正“民主”;职能习惯从主观随意转向严格的法治。     

On the preservation of copula structure under truncation

The author characterizes the copula associated with the bivariate survival model of Clayton (1978) as the only absolutely continuous copula that is preserved under bivariate truncation.     

改进的OBS长度自适应门限组装算法

现有OBS长度自适应组装算法的突发数据长度门限的选择虽然随着业务流的变化而变化,克服了固定长度门限算法输出的突发数据的突发性,但仍然没有考虑业务流的自相似特性,因此不能有效降低输出突发数据的自相似程度和分组阻塞率。针对这一问题,该文提出了一种改进的OBS长度自适应门限组装算法,能根据到达的网络业务流的自相似特性自适应地调整长度门限值。仿真结果表明:在相同的调度算法下,更能降低业务流的自相似性,分组阻塞率降低一个数量级。     

货物运输车辆的调度算法

本文以上海煤炭公司为例,讨论了运煤车辆的计算机调度问题,提出一个数学模型及有效的近似算法。在算法实现中,采用了一些较为先进的数据结构,使运算速度及存储需求均有较大的改善。对实际算例计算结果表明,采用本算法进行运输车辆调度,经济效益比人工调度有明显的提高。     

Principal curves revisited

A principal curve (Hastie and Stuetzle, 1989) is a smooth curve passing through the middle of a distribution or data cloud, and is a generalization of linear principal components. We give an alternative definition of a principal curve, based on a mixture model. Estimation is carried out through an EM algorithm. Some comparisons are made to the Hastie-Stuetzle definition.     

“健康丝绸之路”构建的“政府—社会”复合路径

借鉴社会运动理论,可探索一种融合了政府自上而下和社会自下而上进程的“政府—社会”复合路径,以构建“健康丝绸之路”。社会运动理论的三种视角可为这种复合路径的具体实施与需要关注的环节带来重要启发：首先,当前新冠肺炎疫情的跨国传播暴露了全球公共卫生治理体系存在的严重不足,凸显出构建补充型国际卫生合作模式的必要性与紧迫性;其次,推进“健康丝绸之路”的构建,需要政府和社会层面的协作,将“一带一路”沿线国家的资源充分调动起来,形成优势互补与资源共享。与此同时,要推进健康话语体系的完善,如倡导和促进“人类卫生健康共同体”理念的传播,通过话语和心理共鸣等民心相通的途径,促使国际社会采取联合行动以共同应对全球公共卫生危机。     

Finite mixture models with concomitant information: assessing diagnostic criteria for diabetes

The World Health Organization (WHO) diagnostic criteria for diabetes mellitus were determined in part by evidence that in some populations the plasma glucose level 2 h after an oral glucose load is a mixture of two distinct distributions. We present a finite mixture model that allows the two component densities to be generalized linear models and the mixture probability to be a logistic regression model. The model allows us to estimate the prevalence of diabetes and sensitivity and specificity of the diagnostic criteria as a function of covariates and to estimate them in the absence of an external standard. Sensitivity is the probability that a test indicates disease conditionally on disease being present. Specificity is the probability that a test indicates no disease conditionally on no disease being present. We obtained maximum likelihood estimates via the EM algorithm and derived the standard errors from the information matrix and by the bootstrap. In the application to data from the diabetes in Egypt project a two-component mixture model fits well and the two components are interpreted as normal and diabetes. The means and variances are similar to results found in other populations. The minimum misclassification cutpoints decrease with age, are lower in urban areas and are higher in rural areas than the 200 mg dl^-1 cutpoint recommended by the WHO. These differences are modest and our results generally support the WHO criterion. Our methods allow the direct inclusion of concomitant data whereas past analyses were based on partitioning the data.