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81.
There are a large number of standards concerned with gasketed joints in the UK that are derived from the applications and practice of different industries. Many other countries also have equivalent standards. John Hoyes, technical director of Flexitallic and chairman of the British Standards Committee concerned with gaskets describes the European initiatives to rationalize the standards and improve the technical basis by which they will lead a user to select the joint design and material.  相似文献   
82.
Many organisations suspect that their internal security threat is more pressing than their external security threat. The internal threat is predominantly the result of poor user security behaviour. Yet, despite that, security awareness programmes often seem more likely to put users to sleep than to improve their behaviour. This article discusses the influences that affect a user's security behaviour and outlines how a well structured approach focused on improving behaviour could be an excellent way to take security slack out of an organisation and to achieve a high return for a modest, low-risk investment.  相似文献   
83.
A meta-analytic review of group comparison design studies evaluating peer-assisted learning (PAL) interventions with elementary school students produced positive effect sizes (ESs) indicating increases in achievement (unweighted mean ES = 0.59, SD = 0.90; weighted ES, d = 0.33, p  相似文献   
84.
85.
The ears of lizards are highly directional. The directionality is generated by strong acoustical coupling of the eardrums. A simple lumped-parameter model of the ear followed by binaural comparisons has been shown to perform successful phonotaxis in robot implementations. However, such a model will produce localization errors in the form of response bias if the ears are asymmetrical. We have evaluated how large errors are generated by asymmetry using simulations of the ear model in Mathematica 5.2. The study shows that the effect of asymmetry is minimal around the most directional frequency of the ear, but that biases reduce the useful bandwidth of localization. This work was presented in part at the First European Workshop on Artificial Life and Robotics, Vienna, Austria, July 12–13, 2007  相似文献   
86.
Argues that children's failure on one of Piaget's best known tasks, conservation of solid quantity, reflects ignorance of physical properties rather than inadequate reasoning ability. The evidence for conservation itself, seen from the child's position, is analyzed. It is emphasized that children can learn and enjoy the concepts and methods of physics at much earlier ages than current orthodoxies would indicate. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
87.
In this paper a fuller and clear derivation of the weight vector theory of Coriolis mass flowmeters is given indicating its potential for the prediction of velocity profile effects in both the traditional kind of meter (vibrating tube) and the compact kind (vibrating element inside a duct).  相似文献   
88.
Transient cage induction motor models for use in inverter-fed drives and controllers are reviewed. A simple transient model is presented that includes rotor deep bar effect and magnetic saturation of the magnetising and rotor leakage flux paths. The improved model requires motor details in the form of simple impedance versus frequency characteristics which can be obtained from a variety of external sources. These can range typically from detailed steady-state finite-element solutions to simple experimental measurements. The model is verified experimentally using a 75 kW, 4 pole vector controlled AC motor drive  相似文献   
89.
90.
Serendipitous events have been shown to affect the careers of prominent counseling psychologists. Why should this seem surprising? Unplanned events affect everyone's career. The surprise is due to the widespread but unfounded assumption that career decisions should be the logical outcome of a "true reasoning" process. Counseling psychologists need to (a) broaden their view so that the reluctance to make an occupational commitment in the face of unpredictable future events can be celebrated as open-mindedness, not denigrated as indecisiveness, (b) teach clients that unplanned events are a normal and expected part of the career development process, and (c) teach clients how to generate unplanned events that contribute to a more satisfying life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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