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831.
考虑了时分双工MIMO放大转发中继系统中下行链路基站预编码器、中继预编码器与用户均衡器的联合设计问题。在实际应用中信道估计误差以及信道互易延迟会显著恶化基于理想信道状态信息(CSI)的联合设计性能。从估计误差的分布和互易延迟的时间相关特性出发,建立了综合考虑两方面因素的联合"估计误差-互易延迟"信道模型。基于该模型,针对第一跳传输设计了信道奇异值分解的基站预编码方案,避免了第二跳CSI的反馈开销,然后将给定中继总发送功率约束下最小化用户和均方误差(SMSE)的中继预编码器和用户均衡器进行联合优化,并利用KKT(Karush-Kuhn-Tucker)条件给出了该优化问题的闭合解。数值结果验证了所提方案的鲁棒性和有效性。 相似文献
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834.
以往的《现代教育技术》课程教学效果评价存在诸多问题,本文针对《现代教育技术》课程特点,结合本校实际情况制定教学效果多元评价方案,并在教学中进行实践探索,结果表明教学效果多元评价方案能客观评价学生的学习绩效,充分调动学生的学习兴趣,提高学生的教育技术应用能力。 相似文献
835.
现代教育技术课程是一门理论与实验并重的课程。针对目前课程实验教学中存在的问题,我们进行了“学科一专业一实践”三维结构下的现代教育技术课程实验教学改革,从目标、内容、策略、评价等4个方面进行了系统设计,并对实验教学改革的结果进行了简要的分析。 相似文献
836.
张瑞 《兵团教育学院学报》2013,(4):47-51
研究高校师范生的教育技术能力培养模式,是师范教育新一轮教学改革的突破口。本文以石河子大学师范生为研究对象,以《现代教育技术》公共课的教学为依托,总结并分析当前师范生现代教育技术能力培养中所存在的问题,以此为基础,从公共课的课程设置、理论与实践的课时分配、教学环境创设、教学技能训练和教学评价等方面做出系统设计,形成具有可操作性的创新培养模式。 相似文献
837.
UGURHAN G. BERKOK † 《Defence and Peace Economics》2013,24(3):191-204
The choice between balanced and specialized defence forces depends on the technology of defence output (e.g. whether a force scope multiplier is present), the existence of scope and scale economies, the platform customization costs and, of course, the level of defence budgets. Minimum force element levels (thresholds), and scale economies facilitate specialization as opposed to scope economies (e.g. platform‐sharing), scale diseconomies and the force scope multiplier (e.g. defence weakest‐link technology). When a balanced force is not optimal, the option value of a non‐optimally maintained force element must also include the opportunity cost arising from suboptimal force elements. Shrinking defence budgets may produce two surprising phenomena. If some force elements are shut down as a result of thresholds, the surviving ones may increase in platform numbers as well as enjoying closer‐to‐most‐desirable platforms. Furthermore, if heritage force elements are shut down within the budget contraction environment, overall defence capability might rise. 相似文献
838.
Todd A. Watkins 《Defence and Peace Economics》2013,24(4):353-375
This paper explores whether defense contractors' manufacturing technology advantages over purely commercial firms might be associated with differences in their workforce and organizational practices. It uses unique original data collected specifically to test workforce and organizational complementarities in implementation of advanced manufacturing technology in small manufacturers. Findings are that defense contractors: (1) have higher and deeper rates of advanced manufacturing technology use; (2) have greater perceived success in achieving manufacturing goals; (3) are more likely practitioners across a diverse spectrum of advanced workforce and organizational practices. Then, (4) econometrically, the defense contractors' higher reported levels of achievement in implementing advanced manufacturing technologies are positively associated with those organizational and workforce practice differences. 相似文献
839.
Togzhan Kassenova 《The Nonproliferation Review》2013,20(2):379-401
Because it is a producer and supplier of high-tech dual-use goods as well as a major transit point for WMD-related and military items, Taiwan represents an important case study of national export control systems. Taiwan is not an official member of the major multilateral export control regimes, yet it remains committed to nonproliferation goals. The article explores the strategic trade controls of Taiwan within the context of its nonproliferation policies and commitments. The author discusses the strong and weak aspects of Taiwan's strategic trade controls by looking in detail at key components of the country's export-import control system: legal basis, licensing system, enforcement and compliance mechanism, government-industry outreach, and adherence to nonproliferation treaties and multilateral export control regimes. 相似文献
840.
Mark Wuebbels 《The Nonproliferation Review》2013,20(2):391-404
Taiwan's international status is such that the country's ability to trade and to supply certain goods and technologies remains its primary means of practicing diplomacy and asserting international influence. U.S. pressure to conform to international nonproliferation standards has made the issue of export controls a troubling one for Taiwan. Limiting Taiwan's economic relations affects its ability to sustain itself economically and to maintain productive relations with other nations. On the other hand, as a recipient of U.S. high-technology transfers and security assurances, Taiwan cannot ignore the directives of the United States. The article focuses on this dilemma and how a shift in power to the Democratic Progressive Party is affecting Taiwan's choice between placing limitations on its global economic power or risking being cut off from U.S. technology and losing U.S. security assurances. In order to address this challenge properly, Taiwan will need to reassess its fundamental economic and security interests. 相似文献