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Studies of parental mediation of children's television viewing have included samples of mostly middle- and upper-class Caucasian parents. These studies have only begun to examine mediation in the context of parent-child relationships. This study of 306 low-income, predominately African American mothers assesses macro- and microlevel influences on viewing mediation using Bronfenbrenner's ecological theory of child development. It was hypothesized that factors outside the home (e.g., work hours) influence parents' involvement with children, which, in turn, was predicted to influence viewing mediation. Results supported this model for coviewing and instructive mediation, but not for viewing restrictions.  相似文献   
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Six studies explore the role of goal shielding in self-regulation by examining how activation of focal goals to which the individual is committed inhibits the accessibility of alternative goals. Consistent evidence was found for such goal shielding, and a number of its moderators were identified: Individuals' level of commitment to the focal goal, their degree of anxiety and depression, their need for cognitive closure, and differences in their goal-related tenacity. Moreover, inhibition of alternative goals was found to be more pronounced when they serve the same overarching purpose as the focal goal, but lessened when the alternative goals facilitate focal goal attainment. Finally, goal shielding was shown to have beneficial consequences for goal pursuit and attainment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Web Mining   总被引:1,自引:0,他引:1  
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Specifying real-time properties with metric temporal logic   总被引:16,自引:5,他引:11  
This paper is motivated by the need for a formal specification method for real-time systems. In these systemsquantitative temporal properties play a dominant role. We first characterize real-time systems by giving a classification of such quantitative temporal properties. Next, we extend the usual models for temporal logic by including a distance function to measure time and analyze what restrictions should be imposed on such a function. Then we introduce appropriate temporal operators to reason about such models by turning qualitative temporal operators into (quantitative) metric temporal operators and show how the usual quantitative temporal properties of real-time systems can be expressed in this metric temporal logic. After we illustrate the application of metric temporal logic to real-time systems by several examples, we end this paper with some conclusions.Part of this research has been performed at the Eindhoven University of Technology when the author was working in ESPRIT project 937: Debugging and Specification of Ada Real-Time Embedded Systems (DESCARTES).  相似文献   
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Southwire continuous rod technology has been used for approximately a quarter of a century to produce high-quality copper rod, and ongoing modifications to the process have improved not only the copper product, but the actual efficiency of the production system. Some of these developments have been achieved through automatic quality monitoring and the application of sophisticated control devices.  相似文献   
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带服务能够支持三重应用(即支持语音、视频和数据)至第一英里的客户,例如持续发展的小商业和住宅。FTTx中的主角是GPON(吉比特无源光网络,Gigabit Passive Optical Network),它提供较高的带宽替代DSL和电缆的基于光纤的网络。FTTx为家庭的第一英里应用,诸如光纤到户(FTTH),  相似文献   
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