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151.
Nature and Nurture in Cognition 总被引:1,自引:0,他引:1
152.
Constrained minimization problems considered in this paper arise in the design of beamformers for radar, sonar, and wireless communications, and in the design of precoders and equalizers for digital communications. The problem is to minimize a quadratic form under a set of linear or quadratic constraints. We present solutions to these problems and establish a connection between them. A majorization result for matrix trace and Poincare's separation theorem play key roles in establishing the connection. We show that our solutions can be formulated as generalized sidelobe cancellers (GSCs), which tie our constrained minimizations to linear minimum mean-squared error (LMMSE) estimations. We then express our solutions in terms of oblique projection matrices and establish the geometry of our constrained minimizations. 相似文献
153.
Rosihan M. Ali V. Ravichandran N. Seenivasagan 《Journal of The Franklin Institute》2010,347(9):1762-1781
Differential subordination and superordination results are obtained for analytic functions in the open unit disk which are associated with the Dziok-Srivastava linear operator. These results are obtained by investigating appropriate classes of admissible functions. Sandwich-type results are also obtained. 相似文献
154.
Ali Yakhlef 《Research Policy》2010,39(1):39-46
The community of practice learning theory (Lave and Wenger, 1991) can be credited with establishing the social basis of learning, viewing it as occurring through participation in social practices and activities. However, it remains silent on the cognitive content of what is learned by participants in a community of practice. Nor does it address explicitly the role of individuals in the knowing process. Individuals are merely depicted in terms of a desire to belong to a community, progressing from a peripheral participation position to a more central one. The aim of the present paper is to assess the contribution of Lave and Wenger's (1991) practice theory for educational and other learning social settings. In a schooling context, for instance, Lave and Wenger's (1991) account of learning would imply that what students learn at school is how to relate and belong to the school community. By reducing learning and knowing to participation, and by displacing cognition from individuals to anonymous practices, the practice-based epistemology ignores the significant corpus of content knowledge (such as curriculums) and ascribes too passive a role to individuals and glosses over their differentiated access to resources for changing practices and their differentiated efforts in their social and cognitive development. The present paper suggests an approach to knowledge that takes into account the various facets of knowledge, that is, knowledge as knowledge-productive practices, as content, and as relation to a knowing subject, at the same time preserving the sociality of knowledge and learning. 相似文献
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Alan J. Penny Mehru Ahmed Ali Iffat Farah Sissel Ostberg Robert L. Smith 《International Journal of Educational Development》2000,20(6):443-455
This paper seeks to offer insights into the complexities involved in cross-national collaborative research. It identifies and provides an account of the various issues running through the research process, whilst at the same time derives principles upon which such work should be based. Key narratives were identified by highlighting a number of critical incidents. These narratives were related to issues of ownership, trust, and power, whilst in the course of theorising the research process itself, the metaphors of voice and crossing borders were found to be profoundly empowering and transformative. The complexities of working cross-nationally in the research group, understanding roles, clarifying professional frames and ethical values, at the same time as creating and maintaining a context for effective partnership and participation, made managing and sustaining the research process challenging. 相似文献
158.
Ali GAZNI 《Learned Publishing》2015,28(3):195-204
This study investigated changes in the internationality of national publishers' journals for the period 1990–2013. The patterns of foreign and interregional authorship in papers and references of 4,199 journals from 3,529 publishers were analyzed. The results revealed that foreign authorship increased from 36% to 62% during the period, but interregional authorship only grew from 77% to 82%. The growth in internationality is not the same across disciplines and regions of the world. Agricultural sciences, psychiatry/psychology, and economics and business have the least number of foreign authors, while journals in space science, mathematics, and physics have the most. According to the number of both foreign‐authored papers and foreign‐authored citations, clinical medicine is one of the least international fields. Latin America and Middle East publishers have a greater tendency to publish papers from authors in their countries. In contrast, national publishers in North America have become considerably more international over time. Russia, China, and Brazil publish the least number of foreign authored‐papers in their journals, while Switzerland's journals publish the most. 相似文献
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Medha Joshi Mumtaz Ali Anwar Midrar Ullah Chandrani Kuruppu 《Health information and libraries journal》2014,31(4):318-324
This is the 12th in a series of articles exploring international trends in health science librarianship. This issue describes developments in health science librarianship in the first decade of the 21st century in South Asia. The three contributors report on challenges facing health science librarians in India, Pakistan and Sri Lanka. There is consensus as to the need for education, training and professional development. Starting in the next issue, the focus will turn to Africa, starting with countries in southern Africa. JM 相似文献