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151.
Six measures of divergent thinking were administered to 825 men ranging in age from 17 to 101 over the period from 1959 to 1972; repeat administrations were given to a subset of 278 men after a 6-year interval. Cross-sectional analyses showed curvilinear trends, with an increase in scores for men under 40 and a decline thereafter. Repeated measures analyses on subjects initially aged 33 to 74 generally replicated this finding, whereas cross-sequential analyses suggested a decline for all cohorts tested at a later time. Additional analyses suggested that not all of the decline could be attributed to reduced speed of response production. These longitudinal findings confirm earlier cross-sectional reports of decline in divergent thinking abilities with age. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
152.
The transmission line equations for a three-conductor lossless line in a homogeneous medium are solved in literal (symbolic) form in the time domain. The resulting formulas for the crosstalk voltages are exact and are given in terms of the line parameters and the termination impedances. These formulas demonstrate the effect of the various line parameters on the resulting crosstalk and show how to adjust the line parameters to achieve a desired time-domain crosstalk. In addition, other solution methods are discussed and used to verify the literal solution 相似文献
153.
154.
We present a technique for approximating isotropic BRDFs and precomputed self-occlusion that enables accurate and efficient prefiltered environment map rendering. Our approach uses a nonlinear approximation of the BRDF as a weighted sum of isotropic Gaussian functions. Our representation requires a minimal amount of storage, can accurately represent BRDFs of arbitrary sharpness, and is above all, efficient to render. We precompute visibility due to self-occlusion and store a low-frequency approximation suitable for glossy reflections. We demonstrate our method by fitting our representation to measured BRDF data, yielding high visual quality at real-time frame rates. 相似文献
155.
Lone-Wen Tai Harlan U. Anderson Paul A. Lessing 《Journal of the American Ceramic Society》1992,75(12):3490-3494
Submicrometer powders of complex oxides were prepared via resin intermediates based on a starch type of organic precursor. A commercially available water-soluble starch derivative was (for the first time) used as the organic base for solution synthesis of ceramic powders. Calcination of the charred, fluffy, amorphous resins at a temperature below 600°C for 4 h yielded perovskite powders of Sr-doped LaMnO3 and Sr-doped La(Fe,Co)O3 . Sr-doped LaCrO3 needed to be calcined above 750°C to ensure phase purity and to remove organic residue. Due to the low cost of starch derivatives, the process has the potential of being more economical than the commonly used Pechini's type process, which utilizes citric acid and ethylene glycol. 相似文献
156.
157.
Nelson Linda D.; Mitrushina Maura; Satz Paul; Sowa Marian; Cohen Stanley 《Canadian Metallurgical Quarterly》1993,5(3):374
Internal stability and discriminant validity of the Neuropsychology Behavior and Affect Profile (L. Nelson et al, 1989) were examined in samples of 70 stroke patients and 88 elderly controls. The test is designed to yield indices of premorbid (before-item subset) and present (now-item subset) levels of emotional functioning in each of 5 scales. With coefficient alphas ranging from .76 to .87, results indicated moderate to high internal stability. The test was also able to reliably distinguish between the criterion stroke sample (n?=?42) and a matched group of elderly controls in terms of present levels of emotional functioning (2 wks poststroke). When discriminant validity was examined in terms of premorbid emotional status (before-item subset), group differences were unexpectedly obtained. Clinical and research implications of these results are discussed, noting the possibility of early, noncognitive correlates preceding stroke. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
158.
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160.
Philippe Meunier Robert Bruce Findler Paul Steckler Mitchell Wand 《Higher-Order and Symbolic Computation》2005,18(3-4):245-269
A set-based program analysis establishes constraints between sets of abstract values for all expressions in a program. Solving
the system of constraints produces a conservative approximation to the program's runtime flow of values.
Some practical set-based analyses use explicit selectors to extract the relevant values from an approximation set. For example,
if the analysis needs to determine the possible return values of a procedure, it uses the appropriate selector to extract
the relevant component from the abstract representation of the procedure.
In this paper, we show that this selector-based approach complicates the constraint solving phase of the analysis too much
and thus fails to scale up to realistic programming languages. We demonstrate this claim with a full-fledged value flow analysis
for case-lambda, a multi-branched version of lambda. We show how both the theoretical underpinnings and the practical implementation become
too complex. In response, we present a variant of set-based closure analysis that computes equivalent results in a much more
efficient manner. 相似文献