THE LOT OF THE UNEMPLOYED: A TIME USE PERSPECTIVE

This paper provides new evidence on the time use of employed and unemployed individuals in 14 countries. We devote particular attention to characterizing and modeling job search intensity, measured by the amount of time devoted to searching for a new job. Job search intensity varies considerably across countries, and is higher in countries that have higher wage dispersion. We also examine the relationship between unemployment benefits and job search.     

Current and Future Particulate‐Matter‐Related Mortality Risks in the United States from Aviation Emissions During Landing and Takeoff

Demand for air travel is projected to increase in the upcoming years, with a corresponding influence on emissions, air quality, and public health. The trajectory of health impacts would be influenced by not just emissions growth, but also changes in nonaviation ambient concentrations that influence secondary fine particulate matter (PM_2.5) formation, population growth and aging, and potential shifts in PM_2.5 concentration‐response functions (CRFs). However, studies to date have not systematically evaluated the individual and joint contributions of these factors to health risk trajectories. In this study, we simulated emissions during landing and takeoff from aircraft at 99 airports across the United States for 2005 and for a 2025 flight activity projection scenario. We applied the Community Multiscale Air Quality (CMAQ) model with the Speciated Modeled Attainment Test (SMAT) to determine the contributions of these emissions to ambient concentrations, including scenarios with 2025 aircraft emissions and 2005 nonaviation air quality. We combined CMAQ outputs with PM_2.5 mortality CRFs and population projections, and evaluated the influence of changing emissions, nonaviation concentrations, and population factors. Given these scenarios, aviation‐related health impacts would increase by a factor of 6.1 from 2005 to 2025, with a factor of 2.1 attributable to emissions, a factor of 1.3 attributable to population factors, and a factor of 2.3 attributable to changing nonaviation concentrations which enhance secondary PM_2.5 formation. Our study emphasizes that the public health burden of aviation emissions would be significantly influenced by the joint effects of flight activity increases, nonaviation concentration changes, and population growth and aging.     

Interdisciplinary, functional approach to quality review

Dramatic changes in the standards of the Joint Commission on Accreditation of Healthcare Organizations, as part of its "Agenda for Change," pose new challenges for health care managers. The goal of the "Agenda for Change" is to focus accreditation on the actual performance of important functions while continuously stimulating improvement in the organization's performance and outcomes of care. In 1994, seven important functions--improvement of performance, leadership, management of information, assessment of patients, education of patients and families, operative and other procedures, and treatment of patients--were identified by JCAHO. Performance, as defined by JCAHO, can be measured through observing specific dimensions, such as, availability, safety, timeliness, effectiveness, continuity, efficiency, and respect and caring. These are considered important elements in the determination of quality, value, cost, and patient outcome. In 1995, JCAHO identified 11 important functions--patient rights and organizational ethics, assessment of patients, care of patients, education, continuum of care, improving organizational performance, leadership, management of the environment of care, management of human resources, management of information, and prevention and control of infection. In addition each institution has the opportunity to decide by prioritization where it wants to devote resources. This article reports on one hospital's response to the new JCAHO initiatives.     

Consistency and Accuracy in Decision Aids: Experiments with Four Multiattribute Systems*

There have been a number of multiattribute decision aids developed to aid selection problems. Multiattribute value theory and the analytic hierarchy process are two commonly used techniques. Different systems can result in radically different conclusions if they inaccurately and inconsistently reflect the preference structure of decision makers, or if they are based on inappropriate theoretical models. This study examines the impact of the underlying theoretical model, the method in which preference information is elicited, and the structure of alternatives as influences on the results from using various decision aids. It was found that two systems based on the multiattribute value theory model were just as diverse in their conclusions as were results between AHP and the multiattribute value theory models. Therefore, accuracy of information reflecting decision maker preference is an important consideration. Feedback capable of assuring the decision maker that information provided is consistent is a necessary feature required of decision aids applied to selection problems. The study also found that the way in which information is elicited influenced the result more than did the underlying model. Exact numerical data for complex concepts such as attribute importance and alternative performance on attributes is not necessary, and elicitation procedures that are more natural for the user are likely to be more accurate.     

心理契约对农民工工作绩效影响的实证研究

在正式劳动契约缺失或不完善的现实背景下,基于期望理论和社会交换理论,研究了农民工对雇主责任的履行与过往不履行责任的感知对其工作绩效的影响,同时探讨了期望匹配度的中介作用。研究结果表明,历史心理契约破坏对农民工的心理契约履行具有显著的负相关作用,历史心理契约破坏和心理契约履行均对期望匹配度具有显著的影响,期望匹配度还在心理契约履行与工作绩效的关系之间起着完全中介作用。最后,针对研究假设检验结果的启示和意义进行了探讨。     

GOODNESS-OF-FIT AND DISCORDANCY TESTS FOR SAMPLES FROM THE WATSON DISTRIBUTION ON THE SPHERE

The only parametric model in current use for axial data from a rotationally symmetric bipolar or girdle distribution on the sphere is the Watson distribution. This paper develops methods for evaluating the model as a fit to data using graphical and formal goodness-of-fit tests, and tests of discordancy.     

Jackknifing the Mantel–Haenszel Estimator in Sparse Contingency Tables

This article investigates the performance of two jackknife techniques under an asymptotic model in which the number of 2 × 2 tables increases but the possible marginal configurations remain fixed. These approaches are applied to the Mantel–Haenszel estimator, or transformed versions of this estimator, respectively. The resulting jackknife estimators are shown to be consistent for the common odds ratio. Their asymptotic distributions are derived; they can be used for constructing appropriate sparse-data confidence intervals.     

冷藏系统相变储能装置结构设计

针对目前中型冷藏系统温度浮动大,耗电量高等缺点,提出了基于相变储能技术的冷藏系统,根据现有冷藏系统的特点,介绍了储能装置的工作原理,设计了相变储能装置的结构;采用高效的换能结构实现储能装置的能量交换;设计了复合保温层结构和密封结构以降低能量损耗;设计了储能装置的温度监控系统以及冷量记录功能;创新性提出储能装置的结构参数设计方法。该系统不仅可以满足供冷平稳、节省耗电的要求,且可以作为标准单元串联使用,为相变储能装置应用于生产和实践打下基础。