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141.
Kelty's “recursive public” is defined as a binary: whether or not ownership of intellectual property is legally in the public domain. We propose a broader continuum of recursive depth, which spans the range from shallow constrained generative spaces (e.g., photo memes) to the deeply open collaborations of “critical making” communities. Recursive depth is assessed by the capacity for transformation across three distinct continuums: public/proprietary, virtual/material, and high/low social power. Transformations across all three continuums is not always necessary for deep recursion (as Kelty and others note for many cases of open source), but we argue that paying attention to all three, and treating them as continuums rather than binaries, allows a better evaluation of the capacity for democratizing the technosocial landscape.  相似文献   
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In this paper, the scientific literature and that on the sports sciences relevant to javelin throwing is critically reviewed. This is particularly timely because of the change in the specification of the javelin for the men's event, which was introduced by the IAAF in 1986. A full discussion of the aerodynamics of the javelin is presented with due consideration of the change in pitching moment characteristics that the rules change had brought about. The uses and limitations of current computer programs for simulating javelin flight, in order to estimate optimal release parameters, are profiled. Consideration is also given to the effects of wind velocity, air density, javelin weight and the flutter and spin of the javelin on its flight. The review further considers the optimization of release parameters, drawing upon computer simulations and field-based data. The effects of release speed, release height, release angle, release angle of attack and release pitch rate are assessed. The javelin throwing technique is discussed in relation to cinematographically derived data, including an evaluation of experimental procedures. The importance to successful performance of the grip, the run-up and transition phases, the cross over and delivery strides are each reviewed. Finally, some prognoses as to the direction of future research into this complex throwing skill are offered.  相似文献   
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This paper explores various strategies for creating engaging online learning environments. It describes a framework which identifies and distinguishes between the critical elements needed in the design of online learning: the content of the course, the learning activities and the learning supports. It demonstrates through practical examples how each of these elements can be manipulated in deliberate ways to influence learning processes and outcomes. The paper supports the notion that online courses are best when they arc engineered to take advantage of the learning opportunities afforded by the online technologies, rather than being used as supplements to conventional teaching programs.  相似文献   
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Coordinated by the U.S. Geological Survey (USGS), the National Biological Information Infrastructure (NBII) is a Web-based system that provides access to data and information on the nation’s biological resources. Although it was begun in 1993, predating any formal E-Government initiative, the NBII typifies the E-Government concepts outlined in the President’s Management Agenda, as well as in the proposed E-Government Act of 2002. This article—an individual case study and not a broad survey with extensive references to the literature—explores the structure and operation of the NBII in relation to several emerging trends in E-Government: end-user focus, defined and scalable milestones, public-private partnerships, alliances with stakeholders, and interagency cooperation.  相似文献   
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This paper charts developments in information technology policy in British universities from the creation of the Computer Board for Universities and Research Councils to the present day. Focusing on institutional issues, the various organizational tensions are examined in the context of quasi-collegial policy formulation and management. The impact of operational tensions, arising from a variety of external and internal influences on the implementation of policy, is similarly assessed. The paper concludes with an outline of likely future trends.  相似文献   
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