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The ability of preschool age children to perform generalized relational matching to sample tasks with and without an overt mediating stimulus was examined. This experiment was a direct replication of a study by Lowenkron (1984) and examined a behavioral model relevant to complex human behavior that he later came to call joint control. Children were trained to code two-dimensional stimuli with the help of a handheld mediating stimulus. They were later tested for generalization of relational matching to sample with and without the mediating stimulus. Results indicated high levels of generalized matching to sample with the mediating stimulus and lower levels without. Findings also indicated that generalization was somewhat stronger with symmetrical shapes than with asymmetrical. Results are discussed in terms of a radical behavioral interpretation of complex human behavior.  相似文献   
504.
Some viruses cause tumor regression and can be used to treat cancer patients; these viruses are called oncolytic viruses. To assess whether oncolytic viruses from animal origin excreted by patients pose a health risk for livestock, a quantitative risk assessment (QRA) was performed to estimate the risk for the Dutch pig industry after environmental release of Seneca Valley virus (SVV). The QRA assumed SVV excretion in stool by one cancer patient on Day 1 in the Netherlands, discharge of SVV with treated wastewater into the river Meuse, downstream intake of river water for drinking water production, and consumption of this drinking water by pigs. Dose–response curves for SVV infection and clinical disease in pigs were constructed from experimental data. In the worst scenario (four log10 virus reduction by drinking water treatment and a farm with 10,000 pigs), the infection risk is less than 1% with 95% certainty. The risk of clinical disease is almost seven orders of magnitude lower. Risks may increase proportionally with the numbers of treated patients and days of virus excretion. These data indicate that application of wild‐type oncolytic animal viruses may infect susceptible livestock. A QRA regarding the use of oncolytic animal virus is, therefore, highly recommended. For this, data on excretion by patients, and dose–response parameters for infection and clinical disease in livestock, should be studied.  相似文献   
505.
This paper pursues two goals. First, it explores the connections between national identity and organizational globalization within the context of three British organizations' attempts to synchronize their corporate and organizational identities through diversity management initiatives. Second, it teases out the implications of these connections for current theorizing on organizational identity, looking in particular to extend Hatch and Schultz's (Human Relations, 55 (2002) , pp. 989–1018) processual model of image– culture dynamics. Based on a Foucauldian theoretical frame, and a data set comprising 36 in‐depth interviews, we show the complex and highly particular relationships between articulations of Britishness, and corporate, organizational and personal identities. Such complexity is suggestive of the contradictory connections between national and organizational identities, and of the disjointed, discursive and affective characteristics of organizational identity. Our contribution to the study of organizational identity lies in both an illumination of the local discursive dynamics of identity construction at the individual and collective levels, and an assertion of the ontological role of discourse(s) in structuring understandings and expressions of organizational identity.  相似文献   
506.
In experimental design applications unbiased estimators si 2 of the variances σi 2 are possible. These estimators may be used in Weighted Least Squares (WLS) when estimating the parameters β. The resulting small-sample behavior is investigated in a Monte Carlo experiment. This experiment shows that an asymptotically valid covariance formula can be used if si 2 is based on, say, at least 5 observations. The WLS estimator based on estimators si 2 gives more accurate estimators of β, provided the σi 2 differ by a factor, say, 10.  相似文献   
507.
This paper establishes a sampling theory for an inverted linear combination of two dependent F-variates. It is found that the random variable is approximately expressible in terms of a mixture of weighted beta distributions. Operational results, including rth-order raw moments and critical values of the density are subsequently obtained by using the Pearson Type I approximation technique. As a contribution to the probability theory, our findings extend Lee & Hu's (1996) recent investigation on the distribution of the linear compound of two independent F-variates. In terms of relevant applied works, our results refine Dickinson's (1973) inquiry on the distribution of the optimal combining weights estimates based on combining two independent rival forecasts, and provide a further advancement to the general case of combining three independent competing forecasts. Accordingly, our conclusions give a new perception of constructing the confidence intervals for the optimal combining weights estimates studied in the literature of the linear combination of forecasts.  相似文献   
508.
In certain auction, search, and related models, the boundary of the support of the observed data depends on some of the parameters of interest. For such nonregular models, standard asymptotic distribution theory does not apply. Previous work has focused on characterizing the nonstandard limiting distributions of particular estimators in these models. In contrast, we study the problem of constructing efficient point estimators. We show that the maximum likelihood estimator is generally inefficient, but that the Bayes estimator is efficient according to the local asymptotic minmax criterion for conventional loss functions. We provide intuition for this result using Le Cam's limits of experiments framework.  相似文献   
509.
Jack Eaton 《LABOUR》1993,7(3):35-47
The article argues that there is a need for a new theory of production economics. The premise is that the only extant theory of production in orthodox discourse depends on the maximising model of human behaviour. Adam Smith's bifurcation of economic theory into the province of self-interest and that of justice also blocked off the potential for germinating a theory of production that would draw on motives other than self-interest. The foundations for such an approach have already been set out by Bray in a neglected study. He suggested that mathematical economics was held back, rather than advanced, by its bondage to static equilibrium analysis.  相似文献   
510.
This paper reports on a study which attempted to identify the structure of executive information systems and evaluate their relationship to decision making. The study centered on answering the question: “Where and how do senior executives get their decision-making information?” The data, provided by five senior executives, were gathered by a variety of means which included personal interviews, questionnaires, and logs of the executives' incoming-information transactions for a two-week period. Our findings support beliefs that senior executives receive much information from the environment, that informal systems play a role equal to that of formal systems, and that computers do not provide much information directly to an executive. The study also found that internal information is important and that preferred sources and media vary with different decision roles. The authors suggest that the scope of MIS and DSS be broadened to match those information networks managers actually rely on in daily practice.  相似文献   
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