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31.
This paper uses data envelopment analysis (DEA) to evaluate health expenditures to demonstrate how productivity has changed over time for 46 selected countries in Europe and Central Asia. Our results show that countries could have increased output by 1.2% given the existing level of inputs. The patterns of efficiency change for the observed countries are further analyzed using the Malmquist productivity index (MPI). Decreased productivity growth is related to technical change. Finally, we regress efficiency scores on a set of environmental variables using a Tobit model. The positive influence of hospital beds and primary schooling on efficiency scores demonstrates that countries with better medical environments and a greater number of educational years may enjoy increased efficiency. In addition, there exists a regional effect between Europe and Central Asia.  相似文献   
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In this work we present a simple estimation procedure for a general frailty model for analysis of prospective correlated failure times. Earlier work showed this method to perform well in a simulation study. Here we provide rigorous large-sample theory for the proposed estimators of both the regression coefficient vector and the dependence parameter, including consistent variance estimators.  相似文献   
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Preface     
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Y. S. Hsu  B. M. T. Lin   《Omega》2003,31(6):459-469
This paper considers a single-machine scheduling problem to minimize the maximum lateness. The processing time of each job is a linear function of the time when the job starts processing. This problem is known to be -hard in the literature. In this paper, we design a branch-and-bound algorithm for deriving exact solutions by incorporating several properties concerning dominance relations and lower bounds. These properties produce synergic effects in accelerating the solution finding process such that the algorithm can solve problems of 100 jobs within 1 min on average. To compose approximate solutions, we revise a heuristic algorithm available in the literature and propose several hybrid variants. Numerical results evince that the proposed approaches are very effective in successfully reporting optimal solutions for most of the test cases.  相似文献   
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Demographers often form estimates by combining information from two data sources—a challenging problem when one or both data sources are incomplete. A classic example entails the construction of death probabilities, which requires death counts for the subpopulations under study and corresponding base population estimates. Approaches typically entail ‘back projection', as in Wrigley and Schofield's seminal analysis of historical English data, or ‘inverse’ or ‘forward projection’ as used by Lee in his important reanalysis of that work, both published in the 1980s. Our paper shows how forward and backward approaches can be optimally combined, using a generalized method of moments (GMM) framework. We apply the method to the estimation of death probabilities for relatively small subpopulations within the United States (men born 1930–39 by state of birth by birth cohort by race), combining data from vital statistics records and census samples.  相似文献   
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ABSTRACT

Based on person–organization fit theory, this article moves beyond theories of motivation and social exchange relationships that have often been used in commitment literature. This article contributes to understanding perceptions of organizational culture (OC) and affective commitment (AC) through perceptions of a learning organization (LO). Such understanding helps to tackle current commitment issues in Malaysia through strategic human resources development (HRD) planning and deploying organization development activities. We examined: (a) the extent to which organizations with an embraced LO mediated OC and AC, (b) the most influential component of OC in promoting employee AC, and (c) the most important component of LO for influencing OC and AC. We obtained 516 respondents (64.5% response rate) in selected Malaysian private organizations. It was concluded that LO mediated the relationship between OC and AC. Respect for people was an influential factor of OC for AC, while empowerment played a significant role in LO culture mediating the relationship between OC and AC. HRD practitioners should strategically plan organizational activities, norms, and policies that promote organizational learning processes and a learning culture to enhance AC.  相似文献   
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Biomarkers such as DNA adducts have significant potential to improve quantitative risk assessment by characterizing individual differences in metabolism of genotoxins and DNA repair and accounting for some of the factors that could affect interindividual variation in cancer risk. Inherent uncertainty in laboratory measurements and within-person variability of DNA adduct levels over time are putatively unrelated to cancer risk and should be subtracted from observed variation to better estimate interindividual variability of response to carcinogen exposure. A total of 41 volunteers, both smokers and nonsmokers, were asked to provide a peripheral blood sample every 3 weeks for several months in order to specifically assess intraindividual variability of polycyclic aromatic hydrocarbon (PAH)-DNA adduct levels. The intraindividual variance in PAH-DNA adduct levels, together with measurement uncertainty (laboratory variability and unaccounted for differences in exposure), constituted roughly 30% of the overall variance. An estimated 70% of the total variance was contributed by interindividual variability and is probably representative of the true biologic variability of response to carcinogenic exposure in lymphocytes. The estimated interindividual variability in DNA damage after subtracting intraindividual variability and measurement uncertainty was 24-fold. Inter-individual variance was higher (52-fold) in persons who constitutively lack the Glutathione S-Transferase M1 (GSTM1) gene which is important in the detoxification pathway of PAH. Risk assessment models that do not consider the variability of susceptibility to DNA damage following carcinogen exposure may underestimate risks to the general population, especially for those people who are most vulnerable.  相似文献   
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Several exciting new scientific advances have been made in the past decade toward both understanding the causes of and finding a cure for Parkinson's disease. Heartened by an acceleration in research findings in the past several years, the government has recently called for an infusion of funds from both the National Institutes of Health and private foundations into this burgeoning area of biomedical research. Most currently available conventional treatments for the disease only temporarily delay symptom presentation while doing nothing to halt disease progression. However, the rapidly accelerating pace of research in this field has left researchers hopeful that Parkinson's will be the first major age-related neurodegenerative disease for which we have a viable cure. In this article, advances in various areas of Parkinson's disease research are reviewed.  相似文献   
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