Recent studies have attempted to understand the processes involved in joint attention because of its relevance to both atypical and normal development. Data from a recent study of young children with autism suggests that performance on a delay nonmatch to sample (DNMS) task associated with ventromedial prefrontal functions, but not an A‐not‐B/delayed response task associated with dorsolateral prefrontal cortex, was related to joint attention skills (Dawson et al., 2002). Recent research also suggests that joint attention is associated with dorsalmedial brain systems linked to self‐monitoring (Mundy, 2003). This study investigated the relations among joint attention, DNMS, and self‐recognition performance in a longitudinal study of 39 normally developing toddlers from 14 to 18 months. The results indicated that development on the DNMS and self‐recognition tasks, but not a means end task, predicted joint attention at 18 months. Further analysis showed that the model was only significant for initiating joint attention (IJA). The implications of these results for the neuro‐development of IJA are discussed. 相似文献
We consider the problem of estimating the scale parameter of an exponential or a gamma distribution under squared error loss when the scale parameter θ is known to be greater than some fixed value θ0. Natural estimators in this setting include truncated linear functions of the sufficient statistic. Such estimators are typically inadmissible, but explicit improvements seem difficult to find. Some are presented here. A particularly interesting finding is that estimators which are admissible in the untruncated problem which take values only in the interior of the truncated parameter space are found to be inadmissible for the truncated problem. 相似文献
The authors examined nineteen nonprofit performing arts organizations, investigating the distribution of influence among organizational members, the grouping of volunteers and staff in organizational structures, and the effectiveness of the organizations. The organizations' effectiveness was assessed using multiple performance indicators. The analysis revealed five groupings or configurations of influence, which correlated to the organizations exhibiting the highest and lowest levels of organizational effectiveness. The authors conclude that a variety of structures are associated with good performance but structural dysfunctions are associated with organizational failure, and that members' commitment to an organization's structure is an important element of success. 相似文献
This article offers an exegesis of the passages in von Neumann and Morgenstern (1944, 1947, 1953) that discuss their conception of utility. It is occasioned by two factors. First, as we approach the semicentennial of the publication of Theory of Games and Economic Behavior, its immense impact on economic thought in the intervening years encourages serious reflection on its authors' ideas. Second, misleading statements about the theory continue to appear. The article will have accomplished its purpose if it helps others appreciate the genius and spirit of the theory of utility fashioned by John von Neumann and Oskar Morgenstern. 相似文献
This investigation attempts to measure the relative influence of peer and parental influence on the perceived life satisfaction of two groups of secondary students in Hong Kong. Data on 1906 students from 30 schools were collected through the use of a self-administered questionnaire. Respondents were asked to rate their level of satisfaction on 26 different domains of life on a seven-point scale, ranging from very satisfied to very dissatisfied, as well as their satisfaction with life in general. These 26 items were combined to form six summary indices of life satisfaction: school life, family life, acceptance by others, government, media, and living environment. Two independent variables were used in the analysis of life satisfaction: peer orientation, and parent orientation. Both are composite indices and measure the adolescent's attachment to and identification with his peers or parents. It was found that parent orientation is a better predictor of life satisfaction than peer orientation. Adolescents who are high on parent orientation are more satisfied with every domain of life. They are also more satisfied with life in general. The relationship between peer orientation and life satisfaction is not a clear-cut one. Adolescents with strong peer orientation are more satisfied with school, media, government, and acceptance by others, but are less satisfied with family. There is no significant relationship between peer orientation and environment. The younger adolescents in our sample tend to perceive a higher level of satisfaction than the older adolescents in every domain of life as well as life in general. 相似文献
Current developments in the sociotechnical framework address a number of vital issues that failed to occupy the high ground in its formative years. These include: (i) the purpose of the systems, to create customer value under social and resource constraints, (ii) the context or external business environment, and (iii) the dynamics of the sociotechnical system. Due attention to the dominant issues of purpose, context, and their dynamics make it more meaningful to speak of sociotechnical business systems (STBS) and organizational learning instead of sociotechnical systems (STS) and individual learning. In STBS each unit in an organization has business responsibilities and goal-based couplings with its environment and focuses on the creation of customer value. The implications of this shift from STS to STBS are discussed and illustrated with current research and two summary case studies. 相似文献
The Political Sociology of Florian Znaniecki and Contemporary Politics (in Polish), Olgierd Sochacki (Ed.) Wydawnictwo Gdanskie, The Scientific Society of Gdansk, 1996
Why Read. Internal Space and the Social Function of Literature: An Investigation with. Psychoanalysts and Psychology Students, Graziella Pagliano (Ed.) Bonanno Editore, 1994
Voix Littéraires de Femmes
Cuadernos sobre Vico, Nos 5–6, José M. Sevilla et al. 1995–96
Studi in memoria di Ernesto Grassi Proceedings of the International Conference in Memory of Ernesto Grassi (Ischia, 4–6 October 1993), Emilio Hidalgo‐Serna and Massimo Marassi (Eds), Napoli, La Città del Sole, 1996
Naples Istituto Italiano per gli Studi Fiosofici, La Gittà del Sole, Napoli, 1996
Family, Women and Employment in Central‐Eastern Europe, Barbara Lobodzinska (Ed.) Greenwood Press, 1995 相似文献
Local linear curve estimators are typically constructed using a compactly supported kernel, which minimizes edge effects and (in the case of the Epanechnikov kernel) optimizes asymptotic performance in a mean square sense. The use of compactly supported kernels can produce numerical problems, however. A common remedy is ridging, which may be viewed as shrinkage of the local linear estimator towards the origin. In this paper we propose a general form of shrinkage, and suggest that, in practice, shrinkage be towards a proper curve estimator. For the latter we propose a local linear estimator based on an infinitely supported kernel. This approach is resistant against selection of too large a shrinkage parameter, which can impair performance when shrinkage is towards the origin. It also removes problems of numerical instability resulting from using a compactly supported kernel, and enjoys very good mean squared error properties. 相似文献