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81.
82.
韩礼德系统语法语言分析的模式   总被引:3,自引:0,他引:3  
:语言可以从不同角度加以研究。该文从六个方面简单阐述了系统语法大师M .A .K .Halliday语言分析的模式 ,主要内容包括 :语言的层次 ,链轴和选择轴 ,语法结构 ,语法单位 ,语法的级阶和语法系统  相似文献   
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This paper presents an adaptive strategy for controlling chaotic systems. By employing the phase space reconstruction technique in nonlinear dynamical systems theory, the proposed strategy transforms the nonlinear system into canonical form, and employs a nonlinear observer to estimate the uncertainties and disturbances of the nonlinear system, and then establishes a state-error-like feedback law. The developed control scheme allows chaos control in spite of modeling errors and parametric variations. The effectiveness of the proposed approach has been demonstrated through its applications to two well-known chaotic systems: Duffing oscillator and Rössler chaos.  相似文献   
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Estimating treatment effects for subgroups defined by posttreatment behavior (i.e., estimating causal effects in a principal stratification framework) can be technically challenging and heavily reliant on strong assumptions. We investigate an alternative path: using bounds to identify ranges of possible effects that are consistent with the data. This simple approach relies on fewer assumptions and yet can result in policy-relevant findings. As we show, even moderately predictive covariates can be used to substantially tighten bounds in a straightforward manner. Via simulation, we demonstrate which types of covariates are maximally beneficial. We conclude with an analysis of a multisite experimental study of Early College High Schools. When examining the program's impact on students completing the ninth grade “on-track” for college, we find little impact for ECHS students who would otherwise attend a high-quality high school, but substantial effects for those who would not. This suggests a potential benefit in expanding these programs in areas primarily served by lower quality schools.  相似文献   
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Agricultural development projects have been promoted in many places as a feature of poverty-reduction strategies. Such projects have often been implemented without a strong in-built education component, and hence have had little success. Agricultural projects seek to improve food security by diversifying a household’s resource base and facilitating the social and economic empowerment of women. The present study presents a survey designed to assess the relationship between education level and ability to benefit from dairy-development projects in Kenya. Results reveal higher occupation and employment levels among beneficiary than non-beneficiary households. On the other hand, beneficiaries of poverty-reduction schemes require specialized training. Apart from project-specific training, the level of general education alone cannot predict the attainment of project objectives.  相似文献   
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In Japan, there has been an increased concern about family and community participation in the childs education. Traditionally, the role of parents and community in Japan has been one of support and less one of active involvement in school learning. Since the government commenced education reforms in the last quarter of the 20th century, a more active role for parents and the community in education has been encouraged. These reforms have been inspired by the need to tackle various problems that had arisen, such as the perceived harmful elements of societys preoccupation with academic achievement and the problematic behavior of young people. In this paper, the following issues are examined: (1) education policy and reform measures with regard to parent and community involvement in the childs education; (2) the state of parent and community involvement at the eve of the 20th century.  相似文献   
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