Empirical likelihood confidence intervals for the mean of a population containing many zero values

If a population contains many zero values and the sample size is not very large, the traditional normal approximation‐based confidence intervals for the population mean may have poor coverage probabilities. This problem is substantially reduced by constructing parametric likelihood ratio intervals when an appropriate mixture model can be found. In the context of survey sampling, however, there is a general preference for making minimal assumptions about the population under study. The authors have therefore investigated the coverage properties of nonparametric empirical likelihood confidence intervals for the population mean. They show that under a variety of hypothetical populations, these intervals often outperformed parametric likelihood intervals by having more balanced coverage rates and larger lower bounds. The authors illustrate their methodology using data from the Canadian Labour Force Survey for the year 2000.     

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.     

Diet,mortality and life expectancy: a cross national analysis

"There are numerous reasons why mortality and life expectancy vary between countries. Epidemiological studies seem to indicate that dietary variations may be among them. A sample of 51 countries studied with data from the International Comparisons Project and other sources, shows that after controlling for nutrient intake, consumption of medical goods and services, income distribution, weather, and literacy, countries with more meat and poultry in their diet have lower life expectancies after age five. The results for infant mortality and child death between one and five indicate that a more animal-intensive diet may be actually beneficial, especially if fish consumption is increased and meat and poultry consumption reduced."     

无金属基底吸波结构对TE波的反射

详细分析了ＴＥ极化波以大角度入射到无金属基底的平面多层吸波结构上时的反射特性,导出连接层间电磁场的通用矩阵公式,计算了两层和三层吸波结构的反射系数,并证明了在何种条件下可以获得低的反射率,在此基础上提出了一个简易设计方法。对进气道和进气道内吸波导流板的两层和三层材料设计都获得了良好的特性。     

The impact of supply chain management practices on competitive advantage and organizational performance

Effective supply chain management (SCM) has become a potentially valuable way of securing competitive advantage and improving organizational performance since competition is no longer between organizations, but among supply chains. This research conceptualizes and develops five dimensions of SCM practice (strategic supplier partnership, customer relationship, level of information sharing, quality of information sharing, and postponement) and tests the relationships between SCM practices, competitive advantage, and organizational performance. Data for the study were collected from 196 organizations and the relationships proposed in the framework were tested using structural equation modeling. The results indicate that higher levels of SCM practice can lead to enhanced competitive advantage and improved organizational performance. Also, competitive advantage can have a direct, positive impact on organizational performance.     

Farmers’ Risk‐Based Decision Making Under Pervasive Uncertainty: Cognitive Thresholds and Hazy Hedging

Researchers in judgment and decision making have long debunked the idea that we are economically rational optimizers. However, problematic assumptions of rationality remain common in studies of agricultural economics and climate change adaptation, especially those that involve quantitative models. Recent movement toward more complex agent‐based modeling provides an opportunity to reconsider the empirical basis for farmer decision making. Here, we reconceptualize farmer decision making from the ground up, using an in situ mental models approach to analyze weather and climate risk management. We assess how large‐scale commercial grain farmers in South Africa (n = 90) coordinate decisions about weather, climate variability, and climate change with those around other environmental, agronomic, economic, political, and personal risks that they manage every day. Contrary to common simplifying assumptions, we show that these farmers tend to satisfice rather than optimize as they face intractable and multifaceted uncertainty; they make imperfect use of limited information; they are differently averse to different risks; they make decisions on multiple time horizons; they are cautious in responding to changing conditions; and their diverse risk perceptions contribute to important differences in individual behaviors. We find that they use two important nonoptimizing strategies, which we call cognitive thresholds and hazy hedging, to make practical decisions under pervasive uncertainty. These strategies, evident in farmers' simultaneous use of conservation agriculture and livestock to manage weather risks, are the messy in situ performance of naturalistic decision‐making techniques. These results may inform continued research on such behavioral tendencies in narrower lab‐ and modeling‐based studies.     

文化的根本意蕴及其价值——兼论我国文化建设的合理思路

文化作为一个热点研究问题 ,理论界在许多方面存在分歧。本文着重厘清了人们对文化在概念、价值方面的误解 ,认为文化是一个标志人的主观心态和观念形态的范畴 ,是人处理其与客观世界的多重现实的对象性关系和解决人类内在精神需求的方式 ,这种方式表现为并对象化为千状万态的精神现象和产物 ,并且认为文化对人和社会的价值意义是个客观事实 ,文化的作用已深深地渗透到社会的演进过程中 ,最后从文化的价值意义出发 ,阐述了我国文化建设的合理思路。     

萧灼基关于中国股票市场建立与发展的思想

在证券市场 10余年的历程中 ,萧灼基教授逐步形成了关于中国股票市场建立与发展的思想。这些思想主要包括在社会主义制度下建立股票市场的意义 ;中国发展股票市场所依据的原则以及对股票市场中出现的不规范现象所持有的观点。本文系统探讨了上述思想 ,并指出这些思想能够影响和推动中国股票市场的发展是源于其研究方法的科学性     

What's love got to do with it? Passion and inequality in white‐collar work

Emotion has become an increasingly important aspect of work in the 21st century. In this article, we take stock of the extant literature delineating the role of emotions, especially passion as a cultural schema, in white‐collar workplaces. Scholars have covered extensive ground on emotions at work, but the role of passion remains an underexplored yet significant area. Drawing from recent developments in research on white‐collar work, we argue that the passion schema has become a critical marker in the labor market for sorting individuals into occupations, hiring and promotion within organizations, and assigning value to people's labor. Emergent research suggests that because the expression and perception of passion remain ambiguously defined in the workplace and varies by context, it is pivotal in reproducing social inequalities. In this review, we focus on how privileging passion in the workplace and interpreting it as a measure of aptitude impacts social inequalities by race, gender, and social class. We close by setting an agenda for further research on this topic.     

How Women Talk in Indian Democracy

Qualitative Sociology - In democracies, political institutions based on deliberation offer citizens scope for talk-based participation in development and governance. A prominent example is the...