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排序方式: 共有950条查询结果,搜索用时 15 毫秒
941.
Amir Mokhtari Hao Pang Sofia Santillana Farakos Crystal McKenna Cecilia Crowley Vanessa Cranford April Bowen Sheena Phillips Asma Madad Donald Obenhuber Jane M. Van Doren 《Risk analysis》2023,43(2):324-338
Root cause analysis can be used in foodborne illness outbreak investigations to determine the underlying causes of an outbreak and to help identify actions that could be taken to prevent future outbreaks. We developed a new tool, the Quantitative Risk Assessment-Epidemic Curve Prediction Model (QRA-EC), to assist with these goals and applied it to a case study to investigate and illustrate the utility of leveraging quantitative risk assessment to provide unique insights for foodborne illness outbreak root cause analysis. We used a 2019 Salmonella outbreak linked to melons as a case study to demonstrate the utility of this model (Centers for Disease Control and Prevention [CDC], 2019). The model was used to evaluate the impact of various root cause hypotheses (representing different contamination sources and food safety system failures in the melon supply chain) on the predicted number and timeline of illnesses. The predicted number of illnesses varied by contamination source and was strongly impacted by the prevalence and level of Salmonella contamination on the surface/inside of whole melons and inside contamination niches on equipment surfaces. The timeline of illnesses was most strongly impacted by equipment sanitation efficacy for contamination niches. Evaluations of a wide range of scenarios representing various potential root causes enabled us to identify which hypotheses, were likely to result in an outbreak of similar size and illness timeline to the 2019 Salmonella melon outbreak. The QRA-EC framework can be adapted to accommodate any food–pathogen pairs to provide insights for foodborne outbreak investigations. 相似文献
942.
Donald B. Fedor Soumen Ghosh Steven D. Caldwell Todd J. Maurer Vinod R. Singhal 《决策科学》2003,34(3):513-539
Many organizations are trying to improve the generation and utilization of knowledge. The activities associated with these efforts are identified as organizational knowledge management (KM). While much has been written about knowledge management from the organizational level, the success of such efforts over the long run will depend upon on how KM activities impact important outcomes as perceived by those at the employee level who actually implement the activities. This study used the input‐process‐output framework of team effectiveness to investigate the relationship between selected KM‐related activities on integrated product and process development team members' satisfaction with their project's success and the impact they expected it to have on the organization. The results indicate that team‐level leadership and support (i.e., inputs), along with knowledge generation and dissemination (i.e., processes), are key drivers of member performance‐related ratings (i.e., outputs). Finally, and possibly most importantly, a number of interactions were evident suggesting that the KM processes moderate the effects of the KM inputs. These findings and their implications are discussed. 相似文献
943.
We consider the activity‐based costing situation, in which for each of several comparable operational units, multiple cost drivers generate a single cost pool. Our study focuses on published data from a set of property tax collection offices, called rates departments, for the London metropolitan area. We define what may be called benchmark or most efficient costs per unit of driver. A principle of maximum performance efficiency is proposed, and an approach to estimating the benchmark unit costs is derived from this principle. A validation approach for this estimation method is developed in terms of what we call normal‐like‐or‐better performance effectiveness. Application to longitudinal data on a single unit is briefly discussed. We also consider some implications for the more routine case when costs are disaggregated to subpools associated with individual cost drivers. 相似文献
944.
Donald W. K. Andrews 《Econometrica : journal of the Econometric Society》1999,67(6):1341-1383
This paper establishes the asymptotic distribution of an extremum estimator when the true parameter lies on the boundary of the parameter space. The boundary may be linear, curved, and/or kinked. Typically the asymptotic distribution is a function of a multivariate normal distribution in models without stochastic trends and a function of a multivariate Brownian motion in models with stochastic trends. The results apply to a wide variety of estimators and models. Examples treated in the paper are: (i) quasi-ML estimation of a random coefficients regression model with some coefficient variances equal to zero and (ii) LS estimation of an augmented Dickey-Fuller regression with unit root and time trend parameters on the boundary of the parameter space. 相似文献
945.
Despite the growing number of investigations examining decision support systems (DSS), relatively few empirical studies have evaluated the effects of DSS on problem-solving processes. This study uses protocol analysis to investigate the impact of a specific decision aid on problem-solving processes in a semi-structured problem. Results indicate that decision aids influence the problem-solving processes of decision makers. The effect of a decision aid is found to be contingent on familiarity with the decision aid, task familiarity, and the interaction of these two factors. Suggestions for incorporating interaction effects and problem-solving processes into future examinations are proposed. 相似文献
946.
Michael K. Lindell Meen Chel Jung Carla S. Prater Donald H. House 《Risk analysis》2023,43(10):2129-2146
This study describes a novel method of assessing risk communication effectiveness by reporting an evaluation of a tsunami information brochure by 90 residents of three Pacific coast communities that are vulnerable to a Cascadia Subduction Zone earthquake and tsunami—Commencement Bay, Washington; Lincoln City, Oregon; and Eureka, California. Study participants viewed information that was presented in DynaSearch, an internet-based computer system that allowed them to view text boxes and tsunami inundation zone maps. DynaSearch recorded the number of times each text box or map was clicked and the length of time that it was viewed. This information viewing phase was followed by questionnaire pages assessing important aspects of tsunami hazard and sources of tsunami warnings. Participants gave the longest click durations to what to do in the emergency period during earthquake shaking and in its immediate aftermath before a tsunami arrives—topics that should be displayed prominently in tsunami brochures and emphasized in talks to community groups. The smallest adjusted click durations were associated with advance preparations for a tsunami—topics that can be posted on websites whose URLs are printed in the brochures. 相似文献
947.
Evidence on the Superiority of Analysts Quarterly Earnings Forecasts for Small Capitalization Firms*
Financial analysts provide information to support investment analysis and decisions for an ever increasing number of firms. As part of their services they also produce earnings forecasts for covered firms. While there has been much research investigating the determinants of financial analyst earnings forecast superiority for large, widely-followed firms, little research has focused on smaller firms. Until recently, these smaller firms have been largely ignored. This study focuses exclusively on small firms and provides evidence of differing behavior for such firms compared to results previously reported for large firms. Errors in quarterly earnings per share forecasts of small firms obtained from a univariate time-series model are also examined. Regression results indicate that time-series model parameters possess information content with respect to forecast accuracy for analyst-covered firms only. These results are obtained after controlling for firm size, model adequacy, and industry, quarter, and year effects. This suggests that analysts are more likely to cover small firms for which they are able to decipher information correlated with that impounded in the “shocks” in the quarterly earnings time series as captured by the time-series model parameters. 相似文献
948.
Although children's social care is an area rich in guidance, there is very little research looking at the implementation of new policies in the United Kingdom. In this article, we report on the first stage of a realist evaluation of the implementation of the new Safeguarding Children from Child Sexual Exploitation guidance in Wales. We discuss the development of an initial programme theory, for which we conducted semi-structured interviews with practitioners and managers in three local authorities. We developed programme theories across three areas: policy nature and development, implementation plans and organizational context. Findings suggest that, for policies to produce a significant impact on practice, they need to be sufficiently different to social workers' current perceptions of practice. Second, we found that the coordination between national and local policies is critical for successful implementation as contradictions between them might lead to confusion in what local teams should prioritize. Finally, our findings highlight the importance of effective communication of policy changes, as well as a supportive organizational culture to strengthen implementation in local contexts. These findings illustrate the complexity of policy implementation and the need for policymakers to consider the meaningful involvement of local practitioners in national policy development. 相似文献
949.
950.
The power of an integer programming approach—and more particularly a 0,1 programming approach—to resource allocation problems is not widely appreciated. Recent developments in mathematical programming and in problem formulation enable decision makers to deal explicitly with the special conditions which characterize real world problems in capital budgeting, scheduling, and facilities planning. In this paper, somewhat tutorial in nature, we seek to demonstrate formulation and solution of an equipment selection resource allocation problem with several special conditions. The problem can be solved on any reasonably equipped computer system. Sensitivity studies are also performed and discussed. 相似文献