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131.
Testing symmetry under a skew Laplace model   总被引:3,自引:0,他引:3  
We develop tests of hypothesis about symmetry based on samples from possibly asymmetric Laplace distributions and present exact and limiting distribution of the test statistics. We postulate that the test statistic derived under the Laplace model is a rational choice as a measure of skewness and can be used in testing symmetry for other, quite general classes of skew distributions. Our results are applied to foreign exchange rates for 15 currencies.  相似文献   
132.
A mechanistic model is presented describing the clearance of a compound in a precision-cut liver slice that is incubated in a culture medium. The problem of estimating metabolic rate constants in PBPK models from liver slice experiments is discussed using identifiability analysis. From the identifiability problem analysis, it appears that in addition to the clearance, the compound's free fraction in the slice and the diffusion rate of the exchange of the compound between culture medium and liver slice should be identified. In addition, knowledge of the culture medium volume, the slice volume, the compound's free fraction, and octanol-water-based partition between medium and slice is presupposed. The formal solution for identification is discussed from the perspective of experimental practice. A formally necessary condition for identification is the sampling of parent compound in liver slice or culture medium. However, due to experimental limitations and errors, sampling the parent compound in the slice together with additional sampling of metabolite pooled from the medium and the slice is required for identification in practice. Moreover, it appears that identification results are unreliable when the value of the intrinsic clearance exceeds the value of the diffusion coefficient, a condition to be verified a posteriori.  相似文献   
133.
This paper proposes a developmental framework for foster parents and outlines four distinct growth stages. Such a framework can be of value to program administrators who are required to assess foster parent development during the crucial matching process. To draw a distinction between each developmental stage, specific instrumental tasks and indicators are outlined.  相似文献   
134.
Determining the size and demographiccharacteristics of substance abuse populationsis extremely important for implementing publicpolicies aimed at the control of substanceabuse. Such information not only assists in theallocation of limited treatment resources bythe state, but also in the monitoring ofsubstance abuse trends over time and in theevaluation of innovative policy initiatives. Inthis study, we develop three composite measuresof treatment need. We then use these measuresto estimate treatment need for alcohol abuseand for controlled substance abuse within eachof Florida's 67 counties. This study providesan important empirical component of communityplanning, quantifying and, to a limited degree,specifying the level of need for the substanceabuse treatment of community residents. Anadditional benefit is the development of a costeffective and unobtrusive methodology fordetermining empirically when levels of need arechanging so that treatment levels can beadjusted accordingly. With proper use,policymakers can readily employ the methodologydeveloped in this study in Florida andelsewhere to make better-informed decisions inthe allocation of finite substance abusetreatment resources.  相似文献   
135.
A comprehensive set of variables that have been supported as contributing to overall health and general well-being were analyzed to determine their simple structure using factor analysis and their relative contribution using Pearson correlation. The contributors to general well-being had been theoretically grouped into: emotions, beliefs, temperaments, behaviors, sittuations, experiences and health. The empirical factor structure was compared with the theoretical structure used to develop the variables. Stability was investigated by comparing results with those of another geographically separated group. All subjects were normally functioning working adults. The results demonstrated the feasibility and potential usefulness of using self-report questionnaires with multivariate procedures to measure components of the global general well-being concept.  相似文献   
136.
Despite high expectations, students of the 1960 and 1976 presidentialdebates were unable to find much evidence that these eventssignificantly affected voters' candidate preferences. As a result,scholars have turned increasingly to cognitive consistency theoriesto explain viewers' reactions (Or nonreactions) to debates.This article argues that one key mediating variable determiningwhether or not voters are influenced by debates is their levelof political knowledge. Looking at the largely ignored 1980Carter-Reagan debate, we find that voters with generally lowlevels of knowledge are particularly affected by the debate,and significant shifts in candidate preferences do occur amongthis group. The evidence suggests that the debate was an importantfactor in Ronald Reagan's bid to unseat his Democratic opponent.  相似文献   
137.
Asian and White middle school children were shown photographs of unknown Afro-Caribbean, Asian, and White individuals of approximately the same age as themselves, and asked which one wax most like them, which one they would prefer to be, which ones they would prefer to engage in various activities with, and finally, to allocate positive and negative traits to the three groups or to nobody. A similar majority of both Asian and While children selected an own-race photograph as being most like them, but only about a half selected the own-race photograph as the one they would most like to he. For sharing activities, children showed a strong own-tender preference, followed by an own-race preference. White children stated a greater preference for sharing activities with White children, then with Afro-Caribbean children, and least with Asian children. Asian children preferred Asian and White children the most, Afro-Caribbean the least. On a stereotypes test, similar trends were obtained; White children evaluated While children highest and Asian lowest; Asian children tended to evaluate Asian children highest but to a nonsignificant extent. The relative proportion of Asian/White children in school appeared to have little systematic influence on the results, thus arguing against the contact hypothesis of prejudice reduction in its simple form.  相似文献   
138.
Recent studies have shown that group differences in marital stability and satisfaction can be predicted based on premarital relationship quality. There is also a growing literature indicating that there are distinct types of relationships, both premaritally and developmentally over time. This study examined the relationship between the four premarital types (Vitalized, Harmonious, Traditional, and Conflicted) identified by Fowers and Olson (1992) and relationship outcome over a 3-year period with 393 couples. A substantial relationship was found, with conflicted couples being the most likely to separate or divorce. Vitalized couples had the highest levels of satisfaction, followed by Harmonious, Traditional, and Conflicted couples. Traditional couples were less likely to have divorced than Harmonious couples, even though Harmonious couples had higher premarital relationship satisfaction scores.  相似文献   
139.
This paper presents the results of a study that identified how often a probabilistic risk assessment (PRA)should be updated to accommodate the changes that take place at nuclear power plants. Based on a 7-year analysis of design and procedural changes at one plant, we consider 5 years to be the maximum interval for updating PRAs. This conclusion is preliminary because it is based on the review of changes that occurred at a single plant, and it addresses only PRAs that involve a Level 1 analysis (i.e., a PRA including calculation of core damage frequency only). Nevertheless, this conclusion indicates that maintaining a useful PRA requires periodic updating efforts. However, the need for this periodic update stems only partly from the number of changes that can be expected to take place at nuclear power plants–changes that individually have only a moderate to minor impact on the PRA, but whose combined impact is substantial and necessitates a PRA update. Additionally, a comparison of two generations of PRAs performed about 5 years apart indicates that PRAs must be periodically updated to reflect the evolution of PRA methods. The most desirable updating interval depends on these two technical considerations as well as the cost of updating the PRA. (Cost considerations, however, were beyond the scope of this study.)  相似文献   
140.
Resocialization is pulled out of its structuralist roots and recast into an interactionist framework. Building on a substantive theory of the resocialization experience of becoming an adoptive parent, three theoretical properties of interactionist resocialization are presented. These can be summarized as involving unlearning and relearning some aspects of a core identity; the interpretation and active reconstruction of that identity which has reciprocal effects on all actors involved; and finally, the effects of both situational and trans-situational norms that give shape to the resocialization experience. Suggestions are made for other substantive areas of research that could be used for comparative analysis in order to further refine a formal theory of interactionist resocialization.  相似文献   
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