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51.
52.
C Andrew Clayton Larry Michael Edo D Pellizzari James J Quackenboss 《Quality Assurance: Good Practice, Regulation, and Law》2003,10(3-4):161-175
Multimedia data from two probability-based exposure studies were investigated in terms of how missing data and measurement-error imprecision affected estimation of population parameters and associations. Missing data resulted mainly from individuals'refusing to participate in certain measurement activities, rather than from field or laboratory problems; it suggests that future studies should focus on methods for maximizing participation rates. Measurement error variances computed from duplicate-sample data were small relative to the inherent variation in the populations; consequently, adjustments in nonparametric percentile estimates to account for measurement imprecision were small. Methods of adjustment based on lognormality assumptions, however, appeared to perform poorly. 相似文献
53.
This paper considers the axisymmetric steady flow driven by exact counter rotation of two co-axial disks of finite radius.
At the edges of the rotating disks one of three conditions is (typically) imposed: (i) zero velocity, corresponding to a stationary,
impermeable, cylindrical shroud (ii) zero normal velocity and zero tangential fluid traction, corresponding to a (confined)
free surface and (iii) an edge constraint that is consistent with a similarity solution of von Kármán form. The similarity
solution is valid in an infinite geometry and possesses a pitchfork bifurcation that breaks the midplane symmetry at a critical
Reynolds number. In this paper, similar bifurcations of the global (finite-domain) flow are sought and comparisons are made
between the resulting bifurcation structure and that found for the similarity solution. The aim is to assess the validity
of the nonlinear similarity solutions in finite domains and to explore the sensitivity of the solution structure to edge conditions
that are implicitly neglected when assuming a self-similar flow. It is found that, whilst the symmetric similarity solution
can be quantitatively useful for a range of boundary conditions, the bifurcated structure of the finite-domain flow is rather
different for each boundary condition and bears little resemblance to the self-similar flow. 相似文献
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Dunn Barnaby D.; Dalgleish Tim; Lawrence Andrew D.; Ogilvie Alan D. 《Canadian Metallurgical Quarterly》2007,116(1):1
The accuracy with which dysphoric (Study 1) and clinically depressed (Study 2) individuals make self-regulatory judgments about their own performance in the absence of external feedback and the extent to which this relates to trait self-focused attention (SFA) were examined. Relative to objective criteria, both dysphoric and depressed participants showed a positive judgment bias, overestimating the number of trials they had performed correctly. Relative to control participants, the dysphoric and depressed groups showed a reduction in the extent of this positive bias in that they judged error trials more accurately and correct trials less accurately. Although the dysphoric and depressed groups both reported elevated trait SFA, this did not correlate significantly with accuracy of self-judgment on the performance-monitoring task. Implications for self-regulation models of depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
56.
The Lambda Library (LL) adds a form of lambda functions to C++, which are common in functional programming languages. The LL is implemented as a template library using standard C++; thus no language extensions or preprocessing is required. The LL consists of a rich set of tools for defining unnamed functions. In particular these unnamed functions work seamlessly with the generic algorithms in the C++ Standard Library. The LL offers significant improvements, in terms of generality and ease of use, compared to the current tools in the C++ Standard Library. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
57.
本文利用模糊集理论,提出一种非确定环境的描述方法,并且针对机器人在该类环境中的避障轨迹规划,建立了相应的决策函数和规划策略,最后,给出在PC-386计算机上的仿真试验结果。 相似文献
58.
该研究采用问卷法,通过对30种消费品的调查,分析了消费者对消费品说明中警示信息的阅读倾向性,消费者的危险感受、消费者安全使用商品的自信度、遵守警示信息的可能性、主观危险估计和客观危险性这几项因素之间的关系。结果表明:消费者的危险感受与阅读警示信息的倾向性、遵守警告的要求之间存在高度的一致性;且与自信度呈负相关,所以可以通过研究消费者的危险感受来研究警示信息的有效性;消费者的危险感受、主观危险估计常与商品的客观危险性不一致,所以必须采取一些措施来矫正消费者的危险感受,以确保警示信息发挥应有的安全保障作用 相似文献
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