Weak disintegrability as a form of preservation of coherence

Summary Weak disintegrations are investigated from various points of view. Kolmogorov's definition of conditional probability is critically analysed, and it is noted how the notion of disintegrability plays some role in connecting Kolmogorov's definition with the one given in line with de Finetti's coherence principle. Conditions are given, on the domain of a prevision, implying the equivalence between weak disintegrability and conglomerability. Moreover, weak sintegrations are characterized in terms of coherence, in de Finetti's sense, of, a suitable function. This fact enables us to give, an interpretation of weak disintegrability as a form of “preservation of coherence”. The previous results are also applied to a hypothetical inferential problem. In particular, an inference is shown to be coherent, in the sense of Heath and Sudderth, if and only if a suitable function is coherent, in de Finetti's sense. Research partially supported by: M.U.R.S.T. 40% “Problemi di inferenza pura”.     

马寅初的人口质量观及其现实意义——纪念马寅初诞辰120周年

注重人口质量是马寅初人口思想对马尔萨斯人口论的实质性超越.马寅初关于人口质量的观点主要体现于:人口质量与人口数量是对立的统一;在新时代,人不在乎多,而在乎精;人口质量的提高是德、智、体全面的提高和全民的提高;提高人口质量不能离开本国国情.在现代化进程中我们重温马寅初关于提高人口质量方面的有关观点和主张,有助于我们处理好提高人口质量与稳定低生育水平、保护资源环境、提高农民收入等方面的关系.     

Conditions for Non-confounding and Collapsibility without Knowledge of Completely Constructed Causal Diagrams

In this paper, we discuss several concepts in causal inference in terms of causal diagrams proposed by Pearl (1993 , 1995a , b ), and we give conditions for non-confounding, homogeneity and collapsibility for causal effects without knowledge of a completely constructed causal diagram. We first introduce the concepts of non-confounding, conditional non-confounding, uniform non-confounding, homogeneity, collapsibility and strong collapsibility for causal effects, then we present necessary and sufficient conditions for uniform non-confounding, homegeneity and collapsibilities, and finally we show sufficient conditions for non-confounding, conditional non-confounding and uniform non-confounding.     

沈阳市老年人口现状及其养老保障模式的构建

沈阳作为一个重工业城市 ,在其二次创业过程中人口老龄化问题日益突出 ,因此 ,掌握沈阳市老年人口的生活状况 ,构建适合沈阳市老年人口现状的养老保障模式 ,已经成为沈阳市社会养老保障体系改革的重要内容。     

语篇理解过程及其心理机制

从认知心理学、心理语言学角度讨论了语篇理解的过程及其心理机制。首先从命题、推断、局部与整体连贯三个层次上讨论了语篇理解的认知过程 ;然后从认知构件、认知理解模式对认知结构的模拟以及语篇处理过程中的资源限制三个维度论述了语篇理解的心理机制。文章最后指出 ,语篇理解研究的进一步深化取决于研究方法的改进和研究领域的拓展     

"离农"与韩国农业的现状

韩国自 194 5年独立到 1999年间 ,伴随着工业化的高速进展 ,农村人口也大量流失 ,占总人口的比重由 70 %下降到 9%,使得目前的农村劳动力严重不足与老龄化。人口的减少与剧烈的两极分化 ,使出租地增加到总耕地面积的 4 0 %以上 ,而且基本上是土改前租佃关系的翻版 ,不利于机械化与生产效率的提高。由于农业危机 ,韩国政府希望通过建立股份化的农场 ,使农业生产规模化、现代化 ,并为此做了很多努力 ,但进展不太顺利。     

可持续发展与人口老龄化

从人口自身来讲 ,一是数量要适度 ,二是素质要提高 ,三是结构要合理。人口应始终保持与系统其他要素的协调而不断调整自身的数量、质量与结构。老年人共享社会经济发展成果是实现可持续发展的重要条件 ,文章从 4个方面展开论述 :正确评估老年人创造社会财富的突出贡献 ;充分肯定老年人在发展文教、科技等各项事业中不可替代的巨大作用 ;不要忘记老一代为推动社会进步所付出的沉重代价 ;公平体现老年人一生的社会价值。     

Race and Population Change: A Longitudinal Look at Cleveland Neighborhoods

This paper investigates the relationship of racial composition to neighborhood population change from 1910 to 1990 in the Cleveland metropolitan area. To better understand the long-term dynamics of urban neighborhood change, we focus our analysis upon the longitudinal relationship of race, socioeconomic status, and life cycle stage to changes in neighborhood population densities. First, we find that the more established neighborhoods of the African-American community have experienced dramatic declines in population since 1950, a pattern that represents a clear change from the earlier part of the twentieth century. Second, population loss is experienced through a variety of mechanisms, including the demolition of dwellings, the increase in housing vacancy, and the decline of household size. Third, much of this population loss should be interpreted within the context of high economic distress, occurring most frequently in older African-American communities. Over time, economic distress appears to be more important than race in and of itself in leading to the loss of neighborhood populations.     

乌鲁木齐市经济人口容量动态仿真研究

本文利用系统动力学动态仿真方法,根据乌鲁木齐市历年统计资料,以现实性与合理性为前提,按不同的经济发展速度、投入水平分为三个不同的方案,对乌鲁木齐市经济人口容量从2000年到2050年的50年内的变动趋势进行动态仿真运算,从而了解乌鲁木齐市经济人口容量系统内外因素的相互关系,探索其中主导因素及相关因素的未来发展趋势。