Neighborhood change from the bottom Up: What are the determinants of social distance between new and prior residents?

An important source of neighborhood change occurs when there is a turnover in the housing unit due to residential mobility and the new residents differ from the prior residents based on socio-demographic characteristics (what we term social distance). Nonetheless, research has typically not asked which characteristics explain transitions with higher social distance based on a number of demographic dimensions. We explore this question using American Housing Survey data from 1985 to 2007, and focus on instances in which the prior household moved out and is replaced by a new household. We focus on four key characteristics for explaining this social distance: the type of housing unit, the age of the housing unit, the length of residence of the exiting household, and the crime and social disorder in the neighborhood. We find that transitions in the oldest housing units and for the longest tenured residents result in the greatest amount of social distance between new and prior residents, implying that these transitions are particularly important for fostering neighborhood socio-demographic change. The results imply micro-mechanisms at the household level that might help explain net change at the neighborhood level.     

单位词用法探析

以单位词为中心词的名词词组的深层结构决定单位词的语法特征和语义特征。该深层结构多半可以通过单位词的转换功能映现为主动句或被动句的表层结构。在表层结构中,主语名词除去语法形位后的最后一个音节和谓语动词的第一个音段的组合在语音上是可接纳的。     

存储区域网络iSCSI协议的通信机制研究

介绍了存储区域网络主要采用的组网协议,包括FC协议、FCIP协议、iFCP协议和iSCSI协议,着重研究了一种利用TCP/IPI网组建存储区域网络的协议-iSCSI协议,分析了iSCSI协议的通信机制,比较了在IP网络上实现iSCSI协议通信的3种方法,开发了一种iSCSI协议数据单元与TCP数据帧间的接口算法及其硬件设计,并用 VHDL语言成功进行了行为级的仿真。     

论华中抗日根据地基层政权的民主选举—以乡选为中心的考察

为从根本上改造基层政权,中国共产党领导下的华中抗日根据地广泛开展了一场轰轰烈烈的民主选举运动。根据地颁布了一系列法令、条例,使选举规范化;人民群众在实践中也充分发挥智慧创造了适合自己的选举方式。选举体现了广泛性、平等性、真实性的特点。这一运动使基层政权性质彻底改变,为争取抗战乃至整个新民主主义革命的胜利提供了重要保证。     

美国与英国公益性科技管理体系研究

从国家科技管理机构、科研体系及公共科研成果转化三个方面分析美国和英国的公益性科技管理制度及其发展变化.随着经济全球化和知识自由流动的发展,科学技术在国家经济发展与社会进步方面的作用越来越大,政府在科技管理上的职能与地位也随之发生变化,总的来说是由原来的主要资助者和实施者转变为催化者和促进者.     

建设学习型单位 实现跨越式发展

创建学习型社会,要从每一个单位具体做起。建设学习型单位,基础是建设学习型组织,核心是构筑终身学习体系;保证是建立相应的运行机制。     

物流成本对国际贸易影响的实证分析

多年来中美贸易发展迅速 ,美国成为我国主要出口国家。当今形势下 ,物流成本成为影响中美贸易的主要因素 ;借助计量经济学方法 ,定量地探讨了物流成本对两国贸易尤其是我国出口贸易的影响。     

带中西文量纲演算与转换的符号演算系统

本文介绍作者在自己研制的一个集成化支撑环境支持下，采用公理化方法所开发出的又一个应用系统。在这个系统中，除了可以把古今外多种单位制转换为SI制，可以作多种单位间的量纲转换外，还可以对带中西文量钠的广义表达式作符号演算和数值计算，这是目前其他中外系统暂时都无法实现的功能。这个系统已集成到《推理与计算混合软件包》中。     

Nonresponse weighting adjustment using estimated response probability

To reduce nonresponse bias in sample surveys, a method of nonresponse weighting adjustment is often used which consists of multiplying the sampling weight of the respondent by the inverse of the estimated response probability. The authors examine the asymptotic properties of this estimator. They prove that it is generally more efficient than an estimator which uses the true response probability, provided that the parameters which govern this probability are estimated by maximum likelihood. The authors discuss variance estimation methods that account for the effect of using the estimated response probability; they compare their performances in a small simulation study. They also discuss extensions to the regression estimator.     

现代汉语语义系统刍议

语义单位、语义单位之间的结构关系、结构层次是现代汉语语言意义系统的三要素 ,不同性质的语义单位彼此之间复杂纠联 ,使构成语义系统的两子系统 (词汇意义、语法意义子系统 )、两次子系统 (词法意义、句法意义次子系统 )紧密地联结在—起 ,构成一个统一的内部饶有联系的结构整体