利用Teager-Kaiser算子的多径信号抑制

为了解决多径干扰对无线定位精度的影响,该文在传统的窄带相关技术的基础上,利用TK算子对其进行改进。改进后的技术在不过多地增加计算负担的情况下,不仅保持了窄带相关技术对于长时延多径信号抑制的功能,而且还改善了其对短时延多径信号抑制效果不佳的缺陷。仿真结果证明,该算法对于无线信道的多径信号抑制起到了一定的改善作用,从而提高了无线定位精度。所以,该研究对于无线定位技术的工程应用和理论研究具有一定的参考价值。     

焦点新闻报道的定位及其兴起原因

本文从焦点新闻报道的定位入手，对焦点新闻异军突起的原因和新闻工作者的要求等进行一番“追踪”。希望能在此基础上对我国目前越来越热的焦点报道形式作出比较全面的考察。     

Gaussian copula distributions for mixed data,with application in discrimination

The construction of a joint model for mixed discrete and continuous random variables that accounts for their associations is an important statistical problem in many practical applications. In this paper, we use copulas to construct a class of joint distributions of mixed discrete and continuous random variables. In particular, we employ the Gaussian copula to generate joint distributions for mixed variables. Examples include the robit-normal and probit-normal-exponential distributions, the first for modelling the distribution of mixed binary-continuous data and the second for a mixture of continuous, binary and trichotomous variables. The new class of joint distributions is general enough to include many mixed-data models currently available. We study properties of the distributions and outline likelihood estimation; a small simulation study is used to investigate the finite-sample properties of estimates obtained by full and pairwise likelihood methods. Finally, we present an application to discriminant analysis of multiple correlated binary and continuous data from a study involving advanced breast cancer patients.     

中国考古学的学术定位及对人类学的诉求

由于中国历史悠久,史学传统深厚,中国考古学自产生伊始便定位于历史学.但定位于历史学的中国考古学存在信息提炼不足、理论缺失等弊病,因此,我们有必要引进人类学的理论方法,以促进中国考古学的进一步发展,更好地发挥考古学的威力.     

WORK AND THE CITY IN THE e-SOCIETY A critical investigation of the sociospatially situated character of economic production in the digital content industries in the UK

The aim of this paper is to ground debates about the 'new economy' or 'e-society' in the practice of individuals and companies producing 'new media'. The uncontroversial starting point is to question the generalization in much theorizing, and the tendency to technological reductive accounts of social and economic change. The focus here is to point to the intellectual sources of much policy in this field. The authors present case study material of three very specific parts of the new media/digital content industries (film special effects, computer games and web design). The paper concludes that both technological reductive and agentic accounts have underplayed the continuing importance of the social and economic embeddedness of production, and of the situated co-constitution of technologies, people and places. The differences between industries associated with labour processes, labour markets, users and markets for goods are highlighted. These particularities begin to offer more robust accounts of location and organization.     

广东省生物医药产业集聚水平研究

本文利用 EG 指数和区位商对广东省生物医药产业的总体集聚水平和各地市的相对专业化水平进行了测度,并检验了区位商的统计显著性。研究结果表明：广东省生物医药产业的空间分布在总体上呈现出集聚发展的特征,有5个地区（广州、深圳、珠海、中山和佛山）的专业化水平大于1,其中广州、深圳、中山和珠海的区位商具有统计显著性。     

On tie breaking in competitive location under binary customer behavior

Ties in customer facility choice may occur when the customer selects the facility with maximum utility to be served. In the location literature ties in maximum utility are broken by assigning a fixed proportion of the customer demand to the facilities with maximum utility which are owned by the entering firm. This tie breaking rule does not take into account the number of tied facilities of both the entering firm and its competitors. In this paper we introduce a more realistic tie breaking rule which assigns a variable proportion of customer demand to the entering firm depending on the number of tied facilities. We present a general framework in which optimal locations for the old and the new tie breaking rules can be obtained through Integer Linear Programming formulations of the corresponding location models. The optimal locations are obtained for the old tie breaking rule for different values of the fixed proportion and a comparison with the results obtained for the new tie breaking rule is drawn with data of Spanish municipalities in a variety of scenarios. Finally, some conclusions are presented.     

Understanding public attitudes towards Social Security

There has been very little research on why individuals hold different attitudes toward Social Security. In this article we integrate social location theory and political predisposition theory to provide a framework of explanation and test these theories using a unique sample from the 1998 General Social Survey. Our multivariate results reveal that social structural positions along the lines of race, gender, class and age play a more important role than political predispositions in explain-ing individual differences in support for the current Social Security system against privatisation. Political party affiliation also partly contributes to variation in support for Social Security, but political ideology does not have a significant effect. Our results suggest that with regard to support for Social Security, primary consideration must rest on social structural positions. Racial minorities, women, the poor and the elderly tend to dislike a drastic change in the current Social Security system, and Social Security reform ought to pay attention to their concerns. Our robust finding of a positive relationship between age and support for Social Security also challenges much of the established knowledge, pointing to an intergenerational discord over Social Security. It is also important to differentiate among social welfare programmes in order to uncover the real determinants of public attitudes towards them.     

北京经济活动区位演变趋势分析

本文提出了未来北京经济活动区位的三个重要的演变趋势 ,这三个趋势是 :集聚与分散共存———未来北京经济活动空间分布的基本态势 ;办公业和写字楼———未来北京城区的重要行业和景观 ;园区化———未来北京产业布局的重要形式     

基于Moldflow的带金属嵌件打印机板浇口优化设计

针对带金属嵌件打印机板使用传统注塑模具设计方法时,存在开发周期长、成本高且质量不易保证等缺点,采用 计算机辅助设计软件Pro/E和有限元分析软件Moldflow相结合的方法对制品进行不同浇口位置方案下的“填充+保压 +翘曲”模拟分析,从充填时间、流动前沿温度、气穴、熔接痕和翘曲变形等方面进行了综合比较和评测,确定了最佳浇口 设计方案。结果表明,应用Moldflow软件进行模拟仿真,找出了制件在不同浇口设置环境下缺陷产生的原因,从而为避 免或消除制件上的缺陷,进一步优化模具设计、降低生产成本,为指导实际生产提供合理的依据。