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951.
A special rotation procedure is proposed for the exploratory dynamic factor model for stationary multivariate time series. The rotation procedure applies separately to each univariate component series of aq-variate latent factor series and transforms such a component, initially represented as white noise, into a univariate moving-average. This is accomplished by minimizing a so-called state-space criterion that penalizes deviations of the rotated solution from a generalized state-space model with only instantaneous factor loadings. Alternative criteria are discussed in the closing section. The results of an empirical application are presented in some detail.This research was supported by the Institute for Developmental and Health Research Methodology, University of Virginia. 相似文献
952.
The linear logistic test model (LLTM) specifies the item parameters as a weighted sum of basic parameters. The LLTM is a special case of a more general nonlinear logistic test model (NLTM) where the weights are partially unknown. This paper is about the identifiability of the NLTM. Sufficient and necessary conditions for global identifiability are presented for a NLTM where the weights are linear functions, while conditions for local identifiability are shown to require a model with less restrictions. It is also discussed how these conditions are checked using an algorithm due to Bekker, Merckens, and Wansbeek (1994). Several illustrations are given.This article was written while the first author was a post doctoral fellow at the university of Twente. He gratefully acknowledges the university's hospitality and the financial support by NWO (project nr. 30002). 相似文献
953.
A symbolic computer model, employing the perceptual strategy, is presented for solving Tower of Hanoi problems. The model is calibrated—in terms of the number of problems solved, time taken, and number of moves made—to the performance of 20 normal subjects. It is then "lesioned" by increasing the decay rate of elements in working memory to model the performance of 20 patients with lesions to the prefrontal cortex. The model captures both the main effects of subject groups (patients and normal controls) performance, and the subject groups (patients and normal controls) by problem difficulty interactions. This leads us to support the working memory hypothesis of frontal lobe functions, but for a narrow range of problems. 相似文献
954.
We begin by stating our understanding of the concepts presented in Hopper's paper, then comment on the clinical illustration, and conclude by describing two group situations in which we have applied the concepts we have taken from Hopper's paper. Hopper's fourth basic assumption applies to our work as individual psychoanalysts, family therapists, and group leaders because it integrates psychoanalytic and social understanding. We demonstrate how and why we find Hopper's idea to be a useful advance. 相似文献
955.
Daniel J. Ziegler 《Journal of Rational-Emotive & Cognitive-Behavior Therapy》2001,19(3):137-152
In a critique of Ellis' Rational Emotive Behavior Therapy (REBT) theory of personality, it has been argued that, among other strategies, REBT personality theory could be significantly advanced by attempting to incorporate within it already established theoretical constructs compatible with the cognitive-behavioral movement. Richard Lazarus' prominent, well-articulated, and extensively studied theoretical construct of cognitive appraisal seems ideal in this regard. In the present article, the relevant and salient aspects of Lazarus' construct are described. An attempt is then made to delineate the possible place of cognitive appraisal in the ABC model underlying REBT. Finally, the clinical implications of this proposed ABC model refinement are then explored, and an additional REBT therapeutic strategy based upon the cognitive appraisal construct, reappraisal training, is suggested and briefly described. 相似文献
956.
Dr. Vivian Weil 《Science and engineering ethics》2001,7(4):471-482
To counter confusion about the term ‘mentor’, and address concerns about the scarcity of mentoring, I argue for an “honorific”
definition, according to which a mentor is virtuous like a saint or hero. Given the unbounded commitment of mentors, mentoring
relationships must be voluntary. In contrast, the role of advisor can be specified, mandated, and monitored. I argue that
departments and research groups have a moral responsibility to devise a system of roles and structures to meet graduate students’
and postdoctoral fellows’ needs for information and advice.
An earlier version of this paper was presented at a conference sponsored by the National Science Foundation on Mentoring and
Research Values: Students as Vital Human Resources, Chicago, March 1995. 相似文献
957.
Stephanie J. Bird Ph.D. 《Science and engineering ethics》2001,7(4):455-468
Although the terms mentor and thesis advisor (or research supervisor) are often used interchangeably, the responsibilities
associated with these roles are distinct, even when they overlap. Neither are role models necessarily mentors, though mentors
are role models: good examples are necessary but not sufficient. Mentorship is both a personal and a professional relationship.
It has the potential for raising a number of ethical concerns, including issues of accuracy and reliability of the information
conveyed, access, stereotyping and tracking of advisees, and the abuse of power. Nevertheless, mentors can be critically important
for professional success and are one of a number of elements that affect the responsible conduct of research. In addition,
the community as a whole has a responsibility to mentor junior members.
An earlier version of this paper was presented at a conference sponsored by the National Science Foundation on Mentoring and
Research Values: Students as Vital Human Resources, Chicago, USA, March 1995. 相似文献
958.
精神分裂症动物模型的建立与发展,是当前探索精神分裂症的神经生物学和认知心理学机制的一个关键课题。在加工-保护理论的基础上所建立起来的感觉运动门控精神分裂症模型一直受到普遍的关注。然而,高级认知活动是如何对感觉门控进行调节的这一核心问题目前还有待进一步的解决。本综述围绕着这个核心问题,系统地解释为什么惊反射前脉冲抑制成为目前最为流行的一种精神分裂症的模型,并介绍恐惧情绪学习对感觉运动门控调节作用的最新研究成果,以及阐述这种自上而下的调节作用如何受到在早期发育阶段的社会隔离的影响 相似文献
959.
960.
We studied the association between alexithymia (20-item Toronto Alexithymia Scale, TAS-20) and obesity, and also assessed the construct validity of the TAS-20 in terms of personality dimensions in obese patients. The TAS-20 and its subscales were analysed for their correlations with the NEO Personality Inventory - Revised (NEO PI-R) in an obese sample of 259 patients. Obesity was associated with higher scores on the TAS-20 than a Swedish reference sample. Obese men furthermore scored higher on Externally Oriented Thinking than the obese women. TAS-20 scores correlated with elevated Neuroticism and lower levels of Extraversion and Openness, in agreement with most previous research, but also somewhat unexpectedly with lower Conscientiousness and for women also with lower Agreeableness. The TAS-20 subscales showed divergent associations with personality variables, largely in accordance with previous findings. The associations were more prominent for the women, and some gender-specific patterns not previously reported were also revealed. 相似文献