Roberta L. Grant  Joseph Haney  Angela L. Curry  Michael Honeycutt 《Risk analysis》2009,29(12):1726-1742

The Texas Commission on Environmental Quality (TCEQ) has developed an inhalation unit risk factor (URF) for 1,3-butadiene based on leukemia mortality in an updated epidemiological study on styrene-butadiene rubber production workers conducted by researchers at the University of Alabama at Birmingham. Exposure estimates were updated and an exposure estimate validation study as well as dose-response modeling were conducted by these researchers. This information was not available to the U.S. Environmental Protection Agency when it prepared its health assessment of 1,3-butadiene in 2002. An extensive analysis conducted by TCEQ discusses dose-response modeling, estimating risk for the general population from occupational workers, estimating risk for potentially sensitive subpopulations, effect of occupational exposure estimation error, and use of mortality rates to predict incidence. The URF is 5.0 × 10⁻⁷ per μg/m³ or 1.1 × 10⁻⁶ per ppb and is based on a Cox regression dose-response model using restricted continuous data with age as a covariate, and a linear low-dose extrapolation default approach using the 95% lower confidence limit as the point of departure. Age-dependent adjustment factors were applied to account for possible increased susceptibility for early life exposure. The air concentration at 1 in 100,000 excess leukemia mortality, the no-significant-risk level, is 20 μg/m³ (9.1 ppb), which is slightly lower than the TCEQ chronic reference value of 33 μg/m³ (15 ppb) protective of ovarian atrophy. These values will be used to evaluate ambient air monitoring data so the general public is protected against adverse health effects from chronic exposure to 1,3-butadiene.  相似文献   

    

Qinghua Zhu  Joseph Sarkis  James J. Cordeiro  Kee-Hung Lai 《Omega》2008

Greening the supply chain is increasingly a concern for many business enterprises and a challenge for logistics management in the 21st century. Of particular concern is how to arouse organizational environmental awareness and put environmental activities into practice in the logistics activities of their supply chains. This paper investigates the correlation of two major factors, organizational learning and management support, with the extent of adoption of green supply chain management (GSCM) practices in Chinese manufacturing firms, where their inbound and outbound logistics activities are potential polluters to the environment. Organizational and operational learning was derived from the firm's experience with programs such as total quality management and environmental management systems. Management support included support for GSCM ideas and practices from top and middle-level management and cooperation across organizational functions. We find significant positive relationships between organizational learning mechanisms, organizational support and the adoption of GSCM practices, after controlling for a number of other influences including regulations, marketing, supplier, cost pressures, industry levels of the relevant practice and organizational size. Implications of our findings on logistics management are discussed.  相似文献   

    

James M. Hunt  Joseph Weintraub 《Global Business and Organizational Excellence》2002,21(2):39-44

Managers who coach their employees become known as good managers to work for, developers of talent, and achievers of business results. They also become better leaders in the process. The average manager, however, doesn't coach, believing it would take too much time or be a waste of effort. Such barriers, however, are more psychological than real, and represent an expression of the status quo. The fact is that coaching managers behave differently, and that contributes to their brand. The bottom line: Since most managers don't coach, those who do actively help their employees learn and grow have a competitive advantage, one that can enhance their careers. © 2002 Wiley Periodicals, Inc.  相似文献   

    

Joseph M. Roberts  Daniel W. Tretter 《Global Business and Organizational Excellence》1993,12(2):183-191

In today's competitive climate, even the most successful firms have to look for new and better ways to meet their goals. At Binney & Smith, the journey to improvement began with some careful self-assessment and it continues with a clear business objective-profitable revenue growth through continuous improvement by involvement of all employees.  相似文献   

    

Gray  George M.  Allen  Jon C.  Burmaster  David E.  Gage  Stuart H.  Hammitt  James K.  Kaplan  Stanley  Keeney  Ralph L.  Morse  Joseph G.  North  D. Warner  Nyrop  Jan P.  Stahevitch  Alina  Williams  Richard 《Risk analysis》1998,18(6):773-780

The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT) have focused attention on risk assessment of potential insect, weed, and animal pests and diseases of livestock. These risks have traditionally been addressed through quarantine protocols ranging from limits on the geographical areas from which a product may originate, postharvest disinfestation procedures like fumigation, and inspections at points of export and import, to outright bans. To ensure that plant and animal protection measures are not used as nontariff trade barriers, GATT and NAFTA require pest risk analysis (PRA) to support quarantine decisions. The increased emphasis on PRA has spurred multiple efforts at the national and international level to design frameworks for the conduct of these analyses. As approaches to pest risk analysis proliferate, and the importance of the analyses grows, concerns have arisen about the scientific and technical conduct of pest risk analysis. In January of 1997, the Harvard Center for Risk Analysis (HCRA) held an invitation-only workshop in Washington, D.C. to bring experts in risk analysis and pest characterization together to develop general principles for pest risk analysis. Workshop participants examined current frameworks for PRA, discussed strengths and weaknesses of the approaches, and formulated principles, based on years of experience with risk analysis in other setting and knowledge of the issues specific to analysis of pests. The principles developed highlight the both the similarities of pest risk analysis to other forms of risk analysis, and its unique attributes.  相似文献   

    

Craig R. Carter  Joseph R. Carter 《决策科学》1998,29(3):659-684

Environmental purchasing consists of the purchasing function's involvement in activities that include reduction, recycling, reuse, and substitution of materials. Despite the potentially important role that the purchasing function can play in a firm's environmental activities, little research has been performed to date that examines the factors that impact environmental purchasing. The authors develop and empirically test a theoretical model that examines how interorganizational factors both drive and constrain purchasing's involvement in environmental activities. The empirical findings suggest that environmental purchasing activities will be facilitated through increased coordination with suppliers as well as downstream members of the supply chain, including retailers. The results also suggest the need for increased coordination within the firm, particularly between the purchasing function on the inbound side and marketing and distribution functions on the outbound side.  相似文献   

    

Jessica K. Paulus  Issa J. Dahabreh  Ethan M. Balk  Esther E. Avendano  Joseph Lau  Stanley Ip 《Research Synthesis Methods》2014,5(2):152-161

When examining the evidence on therapeutic interventions to answer a comparative effectiveness research question, one should consider all studies that are informative on the interventions' causal effects. “Single group studies” evaluate outcomes longitudinally in cohorts of subjects who are managed with a single treatment strategy. Because these studies are “missing” a direct, concurrent comparison group, they are typically deemed non‐informative on comparative effectiveness. However, in principle, single group studies can provide information on causal treatment effects by extrapolating expected outcomes in the “missing” untreated arm. Single group studies rely on before–after, implicit, or historical comparisons as a proxy for an ideal comparison group. The validity of these comparisons must be carefully examined on a case‐by‐case basis. While in many cases, researchers will disagree on whether such extrapolations are reasonable; circumstances exist where such studies are generally acceptable as a source of evidence. This article provides an overview of issues related to the interpretation of single group studies with a focus on the assumptions required to support their consideration in comparative effectiveness reviews. We discuss the various settings in which single group studies are employed, common research designs that systematic reviewers need to interpret, and challenges associated with using these designs to inform comparative effectiveness questions. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

    

Joseph W. Sakshaug  Trivellore E. Raghunathan 《Journal of applied statistics》2014,41(10):2103-2122

Small area statistics obtained from sample survey data provide a critical source of information used to study health, economic, and sociological trends. However, most large-scale sample surveys are not designed for the purpose of producing small area statistics. Moreover, data disseminators are prevented from releasing public-use microdata for small geographic areas for disclosure reasons; thus, limiting the utility of the data they collect. This research evaluates a synthetic data method, intended for data disseminators, for releasing public-use microdata for small geographic areas based on complex sample survey data. The method replaces all observed survey values with synthetic (or imputed) values generated from a hierarchical Bayesian model that explicitly accounts for complex sample design features, including stratification, clustering, and sampling weights. The method is applied to restricted microdata from the National Health Interview Survey and synthetic data are generated for both sampled and non-sampled small areas. The analytic validity of the resulting small area inferences is assessed by direct comparison with the actual data, a simulation study, and a cross-validation study.  相似文献   

    

Diane P. Bischak  David J. Robb  Edward A. Silver  Joseph D. Blackburn 《Production and Operations Management》2014,23(5):762-772

In this article, we investigate the (R, S) periodic review, order‐up‐to level inventory control system with stochastic demand and variable leadtimes. Variable leadtimes can lead to order crossover, in which some orders arrive out of sequence. Most theoretical studies of order‐up‐to inventory systems under variable leadtimes assume that crossovers do not occur and, in so doing, overestimate the standard deviation of the realized leadtime distribution and prescribe policies that can inflate inventory costs. We develop a new analytic model of the expected costs associated with this system, making use of a novel approximation of the realized (reduced) leadtime standard deviation resulting from order crossovers. Extensive experimentation through simulation shows that our model closely approximates the true expected cost and can be used to find values of R and S that provide an expected cost close to the minimum cost. Taking account of, as opposed to ignoring, crossovers leads, on average, to substantial improvements in accuracy and significant cost reductions. Our results are particularly useful for managers seeking to reduce inventory costs in supply chains with variable leadtimes.  相似文献   

    

Heather Joseph  Todd A. Carpenter 《Serials Review》2013,39(3):187-191

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