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51.
The internal/external frame of reference (I/E) model explains a seemingly paradoxical pattern of relations between math and verbal self-concepts and corresponding measures of achievement, extends social comparison theory, and has important educational implications. In a cross-cultural study of nationally representative samples of 15-year-olds from 26 countries (total N = 55,577), I/E predictions were supported in that (a) math and verbal achievements were highly correlated, but math and verbal self-concepts were nearly uncorrelated; (b) math achievement had positive effects on math self-concept, but negative effects on verbal self-concept; and (c) verbal achievement had positive effects on verbal self-concept, but negative effects on math self-concept. Supporting the cross-cultural generalizability of predictions, multigroup structural equation models demonstrated good support for the generalizabilify of results across 26 countries participating in the Programme for International Student Assessment project sponsored by the Organisation for Economic Co-operation and Development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
52.
Friedman Richard; Sobel David; Myers Patricia; Caudill Margaret; Benson Herbert 《Canadian Metallurgical Quarterly》1995,14(6):509
The use of medical services is a function of several interacting psychological and social variables as well as a function of physical malfunction. The clinical significance of addressing patients' psychosocial issues has only occasionally been considered. However, the shift in health care economics toward health care maintenance is responsible for the increased interest in interventions in the domain of behavioral medicine and health psychology. Evidence is reviewed for 6 mechanistic pathways by which behavioral interventions can maximize clinical care and result in significant economic benefits. The rationale for further integration of behavioral and biomedicine interventions is also reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
53.
A self-organizing map (SOM) approach for vector quantization (VQ) over wireless channels is presented. We introduce a soft decoding SOM-based robust VQ (RVQ) approach with performance comparable to that of the conventional channel optimized VQ (COVQ) approach. In particular, our SOM approach avoids the time-consuming index assignment process in traditional RVQs and does not require a reliable feedback channel for COVQ-like training. Simulation results show that our approach can offer potential performance gain over the conventional COVQ approach. For data sources with Gaussian distribution, the gain of our approach is demonstrated to be in the range of 1–4 dB. For image data, our approach gives a performance comparable to a sufficiently trained COVQ, and is superior with a similar number of training epoches. To further improve the performance, a SOM–based COVQ approach is also discussed. 相似文献
54.
The stress-crack width relationship has been shown to be the key to an understanding of fracture propagation in and mechanical behaviour in tension of fibre reinforced concrete materials and structures. A model is derived for the stress-crack width relationship for randomly oriented short fibre composites which takes hybrid fibre systems and possible fibre rupture into account. It is shown how this stress-crack width relationship can be included in a structural model for the prediction of crack widths in reinforced concrete structures. With this combination of models a rational design tool for the design of composite materials and structures has been established. It is shown how different fibre systems can be tested for structural applicability and how combined material and structural optimization can take place. 相似文献
55.
Differential optical absorption spectroscopy (DOAS) has become a widely used method to measure trace gases in the atmosphere. Their concentration is retrieved by a numerical analysis of the atmospheric absorption spectra, which often are a combination of overlapping absorption structures of several trace gases. A new analysis procedure was developed, modeling atmospheric spectra with the absorption structures of the individual trace gases, to determine their concentrations. The procedure also corrects differences in the wavelength-pixel mapping of these spectra. A new method to estimate the error of the concentrations considers the uncertainty of this correction and the influence of random residual structures in the absorption spectra. 相似文献
56.
57.
The uncertainty of the crack tip position inside composite coupons during a delamination test under variable fracture mode conditions reduces the accuracy of the experimental results. In this work a method is presented where the crack tip position is located using long embedded Fibre Bragg Grating (FBG) sensors together with the Optical Low Coherence Reflectometry (OLCR) technique. With this technique the local Bragg wavelength is measured which then enables to calculate the axial strain profile within the grating. Carbon/epoxy samples are tested under different mode ratios through the standard Mixed-Mode Bending (MMB) test. Embedded long FBG sensors are used to measure the axial strain profile along the whole grating at different stages of the test. The crack tip can be precisely identified with the long embedded FBGs and then checked by means of a visual inspection after complete delamination of the sample. The data indicate that the long FBG sensor detects the crack tip inside the sample at least as precisely as the traditionally performed visual inspections carried out during the test by means of the lateral markings. Numerical simulations using cohesive elements are in good agreement with the experimental data. 相似文献
58.
59.
Herbert J. Gans Robert A. Dentler Paul Davidoff 《Journal of the American Planning Association. American Planning Association》2013,79(3):189-193
This study develops a research method of assessing people's satisfaction with housing. Instead of the old approaches which consider in fragmented ways the characteristics of the dwelling, or the neighborhood, or the social environment, the author proposes a systems approach in which various interdependent factors are studied in relation to one another. Using the techniques developed, the relative satisfaction of tenants in public housing projects in certain areas of Canada is identified, analyzed, and discussed. 相似文献
60.
S. Herbert Hare Sir Raymond Unwin 《Journal of the American Planning Association. American Planning Association》2013,79(1):20-22
When We Build Again. A Bournville Village Trust Research Publication. George Allen &; Unwin, Ltd., London, 1941. Pp. xii (16), 138. Report Relative to Postwar Reconstruction in the City, Prepared by Improvements and Town Planning Committee, published by The Corporation of London, 1944, pp. 66 plus maps and photographs. The Economic Status of the New York Metropolitan Region in 1944, by The Regional Plan Association, Inc., New York, 1944, xx, 91 pp. 相似文献