Sampling Strategies for Toxic Air Contaminants

Annual concentrations of toxic air contaminants are of primary concern from the perspective of chronic human exposure assessment and risk analysis. Despite recent advances in air quality monitoring technology, resource and technical constraints often impose limitations on the availability of a sufficient number of ambient concentration measurements for performing environmental risk analysis. Therefore, sample size limitations, representativeness of data, and uncertainties in the estimated annual mean concentration must be examined before performing quantitative risk analysis. In this paper, we discuss several factors that need to be considered in designing field-sampling programs for toxic air contaminants and in verifying compliance with environmental regulations. Specifically, we examine the behavior of SO2, TSP, and CO data as surrogates for toxic air contaminants and as examples of point source, area source, and line source-dominated pollutants, respectively, from the standpoint of sampling design. We demonstrate the use of bootstrap resampling method and normal theory in estimating the annual mean concentration and its 95% confidence bounds from limited sampling data, and illustrate the application of operating characteristic (OC) curves to determine optimum sample size and other sampling strategies. We also outline a statistical procedure, based on a one-sided t-test, that utilizes the sampled concentration data for evaluating whether a sampling site is compliance with relevant ambient guideline concentrations for toxic air contaminants.     

略论中国古代传统服饰图案的艺术特征

中国传统服饰中的图案装饰艺术是构成古代灿烂的服饰文化的一个重要的组成部分。它共具有四个艺术特征:一、服饰图案题材丰富多样;二、服饰图案造型具有“写意”性;三、服饰图案纹样具有“标识”性;四、服饰图案构成具有“寓意”化特征。     

新农村建设类设计的重要源泉——解读传统徽派建筑聚落空间的创作手法

通过深层次地解读传统徽派建筑聚落空间的几点重要创作手法,强调了保存和发展传统建筑文化的重要性,并认为具有乡土价值的空间创作手法可以成为新农村建设类设计的重要源泉。     

D-efficient window experimental designs

In the paper we present a new method of calculating sampling intervals, so-called windows, allowing an experimenter some flexibility in timing the sample collection, while a minimum required design efficiency for parameter estimation is assured. The method is based on the Equivalence Theorem for D-optimality what makes the length of each window related to the parameter sensitivities. An example of calculating the windows in a pharmacokinetic study is presented. Some other methods of calculating efficient sampling windows are briefly discussed.     

浅析雅俗观在设计创作中的体现

“雅”文化与“俗”文化是组成我国传统艺术中不可或缺的部分,雅俗的观念一直随着社会经济的发展和民间艺术的繁荣而进行着转变。雅俗观通过具体艺术元素的表现同样也体现在设计创作之中。正确地看待雅与俗在设计创作中的体现,它应当是设计师对民族文化理解后的一种自然的情感流露。“雅”文化与“俗”文化在设计中所起的作用都是我们应该重视的,在设计中体现文化内涵,追求“雅俗共赏”。     

EFFECTS OF INTERNET USE AND SOCIAL RESOURCES ON CHANGES IN DEPRESSION

We examine how people's different uses of the Internet predict their later scores on a standard measure of depression, and how their existing social resources moderate these effects. In a longitudinal US survey conducted in 2001 and 2002, almost all respondents reported using the Internet for information, and entertainment and escape; these uses of the Internet had no impact on changes in respondents' level of depression. Almost all respondents also used the Internet for communicating with friends and family, and they showed lower depression scores six months later. Only about 20 percent of this sample reported using the Internet to meet new people and talk in online groups. Doing so changed their depression scores depending on their initial levels of social support. Those having high or medium levels of social support showed higher depression scores; those with low levels of social support did not experience these increases in depression. Our results suggest that individual differences in social resources and people's choices of how they use the Internet may account for the different outcomes reported in the literature.     

建筑与城市设计中的时间观

时间与形式、功能、空间四要素完备才能组成一个完整的建筑 ,运用时间设计的概念 ,分析和解决当今建筑界和城市规划出现的问题是现实的需要     

薪酬和绩效良性战略互动的探讨

从经济学、激励理论以及组织战略发展角度出发,分别分析薪酬和绩效之间的互动关系存在的客观根源(即等价关系的客观存在)和主观原因(即组织战略发展的需要)。同时通过对目前薪酬设计和绩效考核存在的脱离组织发展战略和员工个性需求等不科学、不合理现象并严重影响二者互动的因素进行了分析,最终从方法和理论角度详细讨论了如何防止二者脱节,如何使二者之间形成良性互动、达到和谐状态的途径。     

服装制板、打板在实践应用中的探索

从服装企业生产的角度,阐述了服装制板、打板在生产实践中的具体应用。并结合实践经验,分析总结了针对不同情况与要求如何快速、准确、合理地制板、打板,以便为服装生产企业提供优质、方便、快捷的技术服务,促进服装企业的快速发展。     

多媒体综合电教室的设计与建设

提出了多媒体综合电教室不宜片面地追求硬件设备的建设问题,探讨了多媒体综合电教室设计的原则及多媒体计算机、投影机、视频展示台、扩音系统等媒体应具备的功能指标。同时,提出了合理的设计与建设方案。