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1.
A 3-wave longitudinal design was used to examine the relationships among emotional restraint, peer drug associations, and gateway drug use in a sample of 1,256 middle school students. Structural equation modeling was used to compare 3 models: (1) One model viewed drug use as a consequence of emotional restraint and peer variables; (2) 1 viewed drug use as a cause of restraint and peer variables; and (3) 1 included reciprocal effects. All 3 models fit the data fairly well. However, the reciprocal model fit the data significantly better than either of the others. Within this model, low emotional restraint was significantly related to subsequent increases in gateway drug use among boys. In contrast, peer drug models and peer pressure were not related to subsequent changes in gateway drug use. Changes in peer drug models were, however, predicted by previous levels of gateway drug use. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
3.
Tan J.C. Crossley P.A. McLaren P.G. Hall I. Farrell J. Gale P. 《Power Delivery, IEEE Transactions on》2002,17(1):68-74
This paper describes a sequential tripping strategy used in a wide area back-up protection expert system (BPES) to combat situations in which protection relays have maloperated or information is missing. The BPES is an innovative back-up protection scheme designed to prevent the occurrence of widespread blackouts. The BPES evaluates the certainty that transmission lines are likely to be affected by the fault and uses a sequential tripping strategy to isolate the fault if a firm decision is not available due to maloperated relays and/or missing information. The mode of analysis and the sequential tripping strategy ensures that the BPES will clear a fault at minimum risk to the network. An example is included to demonstrate how the certainty factor based sequential tripping strategy is employed by the BPES to clear a fault which occurred on the South Western part of the UK National Grid System 相似文献
4.
This paper presents an investigation on a single-mode-multimode-single-mode fiber structure. A one-way guided-mode propagation analysis for the circular symmetry waveguide is employed to model the light propagation and the approximated formulations are derived and evaluated concerning the accuracy. Phase conjunction of the multimode interference within the fiber structure is revealed. A simple way to predict and analyze the spectral response of the structure is presented through the space to wavelength mapping with the derived approximated formulations. The prediction of spectral response is verified numerically and experimentally. 相似文献
5.
We formulate a class of difference schemes for stiff initial-value problems, with a small parameter ε multiplying the first derivative. We derive necessary conditions for uniform convergence with respect to the small parameter ε, that is the solution of the difference scheme uih satisfies |uih−u(xi)| Ch, where C is independent of h and ε. We also derive sufficient conditions for uniform convergence and show that a subclass of schemes is also optimal in the sense that |uih−u(xi)| C min (h, ε). Finally, we show that this class contains higher-order schemes. 相似文献
6.
The functional reanimation of paralyzed limbs has been a longstanding goal of neural prosthetic research, but clinically successful applications have been elusive. Natural voluntary limb movement requires four major elements: actuators (i.e., motor units), sensors (i.e., somatosensory afferents), commands (i.e., cerebral cortical activity), and control (i.e., integration of the previous three elements at various levels of the neuraxis). Prosthetic equivalents of each of these elements are, as yet, primitive and often cumbersome to deploy, but new technologies promise substantial improvements for all. This article focuses on one such technology, bionic neuon (BION) modular microimplants, and its relationship to alternative and complementary technologies. The challenge remains to select and integrate them into systems that can be tailored efficiently to the widely disparate needs of patients with various patterns of weakness and paralysis. 相似文献
7.
Gerald Leach 《Energy Policy》1991,19(10):918-925
The UK differs from may other industrialized nations in that its carbon dioxide (CO2) emissions from energy use have declined in recent years despite relatively rapid economic growth. In all sectors but transport, substantial reductions have already occurred in the level of carbon emissions per unit of GDP output. At the same time, a number of official and unofficial studies have pointed out that the UK has one of the largest remaining potentials amongst comparable industrialized countries for achieving further CO2 reductions through the implementation of cost-effective energy efficiency and fuel switching measures. This paper discusses past and present patterns of energy use and carbons emissions in the UK. The analysis then examines historical trends in UK energy policy and presents policy options for further reducing the UK's energy-use and carbon emissions in the future. 相似文献
8.
Allen Daniel N.; Strauss Gregory P.; Kemtes Karen A.; Goldstein Gerald 《Canadian Metallurgical Quarterly》2007,21(6):713
Hemispheric involvement in reasoning abilities has been debated for some time, and it remains unclear whether the right hemisphere's involvement in problem solving is modality specific or dependent on the type of spatial reasoning required. In the current study, 2 types of nonverbal reasoning abilities were examined, spatial reasoning and proportional reasoning, in 109 patients with cerebrovascular disease that was confined to either the right or the left hemisphere or was diffuse in nature. Results indicated that no lateralizing effects were present based on type of spatial reasoning. Findings are consistent with the suggestion that higher order cognitive processes involved in nonverbal abstraction and problem solving are not strongly lateralized to the right hemisphere but rather are more generally distributed throughout the cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
The effects of age stereotyping on subjects' ratings of interviewee potential were investigated using a simulated auditory interview. Male and female participants (N?=?156) listened to a 12-min interview of a supervisory candidate applying for a temporary position in industry and then rated the interviewee's qualifications for the supervisory position. Participants gave higher overall interview ratings to a younger interviewee even though he had the same qualifications as an older interviewee. Ratings given to the older interviewee, however, were not significantly different from those given to an interviewee whose age was not designated. The findings are discussed in terms of the influence of both positive and negative age stereotypes on ratings of applicant potential. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
Comments on the article by S. T. Fiske et al (see record 1992-07509-001) praising the American Psychological Association's (APA's) amicus brief intended to inform the Supreme Court of current scientific thinking regarding gender stereotyping. A balanced perspective, it is argued, should include both research supporting an argument and findings that are inconsistent with that argument. The APA brief gave no indication of contradictory findings. Moreover, review of the research cited indicates that more than half of the studies do not support the argument for which they were cited. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献