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1.
Methods for a sequential test of a dose-response effect in pre-clinical studies are investigated. The objective of the test procedure is to compare several dose groups with a zero-dose control. The sequential testing is conducted within a closed family of one-sided tests. The procedures investigated are based on a monotonicity assumption. These closed procedures strongly control the familywise error rate while providing information about the shape of the dose-responce relationship. Performance of sequential testing procedures are compared via a Monte Carlo simulation study. We illustrae the procedures by application to a real data set.  相似文献   
2.
This paper establishes a nonparametric estimator for the treatment effect on censored bivariate data under unvariate censoring. This proposed estimator is based on the one from Lin and Ying(1993)'s nonparametric bivariate survival function estimator, which is itself a generalized version of Park and Park(1995)' quantile estimator. A Bahadur type representation of quantile functions were obtained from the marginal survival distribution estimator of Lin and Ying' model. The asymptotic property of this estimator is shown below and the simulation studies are also given  相似文献   
3.
This study compares three variations in how researchers construct middle childhood social networks: (1) with friendships or affiliations as a relational tie; (2) with children providing self reports of relationships, or in addition, multi-informant reports of relationships in which they are not involved; and (3) whether network computation is correlational or distance-based . The sample was 357 fourth- and fifth-grade students in 17 classrooms. The strongest differences were between self-reported friendship and affiliative networks. Results showed that compared with affiliations, friendship networks had smaller groups, more isolates, and lower fall-to-spring stability. Agreement in social placement between friendship and affiliative networks was generally average, but poor for unpopular and aggressive children. Multi-informant affiliative networks were most robust in their positioning of aggressive children. Multi-informant centrality was uniquely uncorrelated with aggression. Network computation differences were not substantial. Discussion focuses on recommendations for research and the educational promise of network technology.  相似文献   
4.
ABSTRACT

How do parties in migrant-sending countries engage with the diaspora? Migrants exercise an increasingly important voice in electoral politics in their home countries, though they often either cannot legally vote or vote in very low numbers, yet parties attempt to leverage the influence they believe migrants have over voters at home. However the degree and manner by which parties reach out to diaspora citizens varies widely. A case study of El Salvador points to party organisation as a determinant of variation among parties in diaspora campaigning, based on interviews with Salvadoran party elites in the U.S. and El Salvador, party documents, and historical comparison of campaign activities of El Salvador's two major parties, ARENA and FMLN, over three presidential elections and one mayoral election. FMLN, with a hierarchical model and base committee structure, more effectively mobilizes diaspora support while ARENA, with a horizontal model and sectoral structure, exhibits difficulties in party-diaspora coordination and largely makes indirect and symbolic references to diaspora issues.  相似文献   
5.
In this paper, we consider Markov fluid models with jumps which are useful for e.g. insurance risk modeling and the performance analysis of high-speed data networks. Recently, Ahn and Ramaswami [Ahn, S. & Ramaswami, V. (2004). Transient analysis of fluid flow models via stochastic coupling to a queue. Stochastic Models, 20 (1) 71–101] provided a transient analysis of the Markov modulated fluid flow model using stochastic coupling to a queueing model. Here we extend their results and provide a transient analysis of Markov fluid models with jumps. We also present some numerical examples.  相似文献   
6.
Child and Adolescent Social Work Journal - Since the ultimate goal of adoption is to provide children a happy life in a stable family environment, our major concern is children’s happiness...  相似文献   
7.
In line with the economic crisis and rapid socio-demographic changes, the interest in ??social?? and ??well-being?? indicators has been revived. Social indicator movements of the 1960s resulted in the establishment of social indicator statistical frameworks; that legacy has remained intact in many national governments and international organisations. With this background, this research examines whether existing social indicator frameworks are valid and effective enough to address increasingly complex social issues. The authors argue that, despite some improvements, current social indicators fail to provide an effective framework and tool for measuring the progress of social welfare and also for developing or reforming social policy to cope with newly emerging social problems. While proposing a new social indicator framework based on the Organisation for Economic Co-operation and Development??s pressure-state-response (PSR) model, the paper argues that the new framework should be more than displaying static numbers but should use dynamic statistics revealing causes and effects and shedding light on social and policy changes.  相似文献   
8.
This article examines the effectiveness of current risk management practices to reduce project risk using a multinational, multi‐industry study across different scenarios and cultures. A survey was administered to 701 project managers, and their supervisors, in seven industries and three diverse countries (New Zealand, Israel, and Japan), in multiple languages during the 2002–2007 period. Results of this study show that project context—industry and country where a project is executed—significantly impacts perceived levels of project risk, and the intensity of risk management processes. Our findings also suggest that risk management moderates the relationship between risk level and project success. Specifically, we found that even moderate levels of risk management planning are sufficient to reduce the negative effect risk levels have on project success.  相似文献   
9.
Estimation of long-run inefficiency levels: a dynamic frontier approach   总被引:2,自引:0,他引:2  
Cornwell, Schmidt, and Sickles (1990) and Kumbhakar (1990), among others, developed stochasticfrontier production models which allow firm specific inefficiency levels to change over time. These studies assumed arbitrary restrictions on the short-run dynamics of efficiency levels which have little theoretical justification. Further, the models are inappropriate for estimation of long-run efficiencies. We consider estimation of an alternative frontier model in which firmspecific technical inefficiency levels are autoregressive. This model is particularly useful to examine a potential dynamic link between technical innovations and production inefficiency levels. We apply our methodology to a panel of US airlines.  相似文献   
10.
Verallgemeinerte DEA-Modelle zur Performanceanalyse   总被引:2,自引:1,他引:1  
Dyckhoff and Allen derived a generalisation of Data Envelopment Analysis (DEA) in order to measure ecological efficiency. This approach distinguishes between inputs and outputs of an activity on the one hand and their impact on the relevant evaluation criteria—referred to as efforts and benefits—on the other hand. Thereby, the current framework of the DEA for analysing the relative performance of productive units is fundamentally extended. The relevance of this framework is not limited to ecological aspects because many essential problems of DEA application can be solved. Against this background, the paper presents a formalisation of the generalised DEA, applies it to the well-known basic DEA models, and concretises these models for linear effort and benefit functions.  相似文献   
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