On the Effect of Probability Distributions of Input Variables in Public Health Risk Assessment

A central part of probabilistic public health risk assessment is the selection of probability distributions for the uncertain input variables. In this paper, we apply the first-order reliability method (FORM)^(1–3) as a probabilistic tool to assess the effect of probability distributions of the input random variables on the probability that risk exceeds a threshold level (termed the probability of failure) and on the relevant probabilistic sensitivities. The analysis was applied to a case study given by Thompson et al. ⁽⁴⁾ on cancer risk caused by the ingestion of benzene contaminated soil. Normal, lognormal, and uniform distributions were used in the analysis. The results show that the selection of a probability distribution function for the uncertain variables in this case study had a moderate impact on the probability that values would fall above a given threshold risk when the threshold risk is at the 50th percentile of the original distribution given by Thompson et al. ⁽⁴⁾ The impact was much greater when the threshold risk level was at the 95th percentile. The impact on uncertainty sensitivity, however, showed a reversed trend, where the impact was more appreciable for the 50th percentile of the original distribution of risk given by Thompson et al. ⁴ than for the 95th percentile. Nevertheless, the choice of distribution shape did not alter the order of probabilistic sensitivity of the basic uncertain variables.     

Perception of Ecological Risk to Water Environments

This paper examines lay and expert perceptions of the ecological risks associated with a range of human activities that could adversely affect water resource environments. It employs the psychometric paradigm pioneered in characterizing perceptions of human health risks, which involves surveys to obtain judgments from subjects about risk items in terms of several important characteristics of the risks. The paper builds on a previous study that introduced ecological risk perception. This second study employs a larger, more diverse sample, a more focused topic area, and comparisons between lay and expert judgments. The results confirm that a small set of underlying factors explain a great deal of variability in lay judgments about ecological risks. These have been termed Ecological Impact, Human Benefits, Controllability , and Knowledge. The results are useful in explaining subjects' judgments of the general riskiness of, and need for regulation of, various risk items. The results also indicate several differences and areas of agreement among the lay and expert samples that point to potential key issues in future ecological risk management efforts for water resources.     

ATSDR Science Panel on the Bioavailability of Mercury in Soils: Lessons Learned

On the basis of discussion and analysis during and following an ATSDR science panel on the bioavailability of mercury in soils, it is apparent that the default assumption of 100% relative bioavailability for mercury-contaminated soils is excessively conservative. However, current knowledge does not allow the development of default assumptions or guidelines for determining relative bioavailability of mercury in soils. Until such default assumptions or guidelines can be developed, site-specific assays of bioavailability, preferably using either animal bioassays or validated in vitro techniques, may provide the best approach for estimating soil-mercury bioavailability.     

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.     

组织成员绩效结构理论研究述评

在过去的许多年,对工作绩效的研究出现了许多问题,不断重复的实证研究以及在工作绩效结构研究方面的混乱状态引起了学者们的严厉批评.这方面的研究主要包括组织公民行为、亲社会组织行为、关系绩效和任务绩效、角色行为和角色外行为以及任务绩效和非任务绩效.正是这些理论导致我们对工作绩效范围的重新思考.继续将非任务绩效看作是超越工作范畴或正式系统的非报酬行为是没有益处的.文章对组织成员行为绩效的主要成果给予介绍和评价,其主要目的是综合国内外现存文献,以便于将来学者们研究.     

供应链绩效评价指标体系与评价方法研究

供应链管理(SCM)与现行企业模式有较大区别,其绩效评价指标体系的建立与评价方法也就有其特殊性,目前这方面的研究还略显不足。本文在综合分析现有的SCM评价指标体系的基础上,初步建立了一套适合我国SCM绩效评价的指标体系。同时,给出了SCM绩效评价的多级动态模糊综合评价方法。     

差异性、相似性和受教育背景对高层管理团队影响的国外研究综述

高层管理团队成员组成的差异性、相似性及其成员的受教育背景以不同的方式影响着它的绩效。国外关于这些特征对高层管理团队绩效的影响已经作了大量的研究,而国内目前尚没有相关研究。本文综述国外关于高层管理团队成员组成的差异性、相似性及其成员的受教育背景对其绩效的影响的相关研究和结论。     

Pipage Rounding: A New Method of Constructing Algorithms with Proven Performance Guarantee

The paper presents a general method of designing constant-factor approximation algorithms for some discrete optimization problems with assignment-type constraints. The core of the method is a simple deterministic procedure of rounding of linear relaxations (referred to as pipage rounding). With the help of the method we design approximation algorithms with better performance guarantees for some well-known problems including MAXIMUM COVERAGE, MAX CUT with given sizes of parts and some of their generalizations.     

基于获取决策优先权的零售商战略联盟效益分析

对于由一个供应商和多个零售商组成的单一产品、单周期供应链,在确定型市场、零售商成本对称以及供应商具有关于零售商成本结构完全信息的情况下,考虑了同时带来运作成本与决策权分配变化(基于获取决策优先权)的零售商定货数量决策联盟。利用博弈论方法,研究了获取决策优先权的零售商战略联盟对参与联盟的零售商、未参与联盟的零售商、供应商以及供应链整体收益的影响。证明这种零售商战略联盟不可能使供应链中所有成员都同时增加收益。但在一定的条件下,联盟能实现某种部分"多赢";使供应链整体、供应商和参与联盟的零售商收益增加,或使供应商和参与联盟的零售商收益增加。     

跨国公司经营业绩评价方法的研究

跨国公司经营业绩评价较之国内经营企业的经营业绩评价有其特殊的复杂性。本文提出跨国公司经营业绩评价的一种新方法,构造跨国公司经营业绩评价标准的综合效用值模型,建立跨国公司经营业绩评价系统的整体模型。