排序方式: 共有137条查询结果,搜索用时 187 毫秒
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陈华 《兵团教育学院学报》2001,11(4):32-34
利用Hardy Littlewood极大算子及性质与分数次极大算子及性质 ,证明了u(x)在Lq(Rn) ,L∝ ,Lq(E)空间上是有界的 ,Coσoπeβ定理应予以推广。 相似文献
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邢焕革 《海军工程大学学报》1997,(2)
基于知识的模型表示是信息管理系统,特别是决策支持系统(DSS)的基础。根据模型管理和模型建立动态性原则的要求,提出了模型知识化的框架表示法,并给出了应用实例。 相似文献
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分析了影响舰艇主动力装置选型的诸要素,考虑了其间的联系与制约,提出了主动力装置选型的综合评价体系与方法. 相似文献
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Bleddyn E. Bowen 《战略研究杂志》2019,42(3-4):532-556
Colin Gray once lamented the absence of a ‘Mahan for the final frontier’ and spacepower theory in strategic studies. This article proposes the command of space as the fundamental concept of spacepower theory, and that Mahan himself has much to offer in the endeavour of spacepower theory-making than has hitherto been realised. The theory is advanced by tempering versions of the ‘command of space’, stressing its educational intent, and explaining the nuanced sub-concepts of space control and denial through understanding some precedents set by seapower theory. In the process, aspects of Mahanian and Corbettian seapower theory are unified. 相似文献
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《防务技术》2019,15(6):964-971
Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment, it is prone to the partial loss of control effectiveness (PLCE) fault. An adaptive fault-tolerant control algorithm is designed for a space robot system with the uncertain parameters and the PLCE actuator faults. The mathematical model of the system is established based on the Lagrange method, and the PLCE actuator fault is described as an effectiveness factor. The lower bound of the effectiveness factors and the upper bound of the uncertain parameters are estimated by an adaptive strategy, and the estimated value is fed back to the control algorithm. Compared with the traditional fault-tolerant algorithms, the proposed algorithm does not need to predetermine the lower bound of the effectiveness factor, hence it is more in line with the actual engineering application. It is proved that the algorithm can guarantee the stability of the closed-loop system based on the Lyapunov function method. The numerical simulation results show that the proposed algorithm can not only compensate for the uncertain parameters, but also can tolerate the PLCE actuator faults effectively, which verifies the effectiveness and superiority of the control scheme. 相似文献
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Sundara Vadlamudi 《The Nonproliferation Review》2013,20(1):199-223
In January 2004 U.S. President George W. Bush and Indian Prime Minister Atal Behari Vajpayee announced the Next Steps in Strategic Partnership (NSSP), a bilateral initiative to expand cooperation in the areas of civilian space activities, civilian nuclear programs, and high-technology trade and to expand discussions on missile defense. Today, India and the United States view the NSSP initiative as a tool to transfer high-technology items to India without compromising U.S. nonproliferation goals. The success of this proposal depends on U.S. efforts to modify its nonproliferation regulations and India's efforts to implement stringent regulations to control the flow of sensitive technologies within its borders. This report examines the Indo-U.S. NSSP initiative and associated agreements, discusses the set of reciprocal steps agreed upon by India and the United States, reviews the extent of technology transfer permissible under existing U.S. nonproliferation regulations, and presents some preliminary conclusions on the NSSP agreement. 相似文献
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Vasilis Zervos 《Defence and Peace Economics》2013,24(4):365-377
This paper models the space race between the US and the Soviet Union during the Cold War using time series econometric modelling. The analysis shows that, post the Vietnam‐war era, military considerations play a key role in explaining the behaviour of US space expenditure. In particular, the US Department of Defense (DoD) Strategic Defense Initiative (SDI) of the early 1980s is shown to result in a changing structure of the space race. This is expected to continue in the future with the current anti‐ballistic missile (ABM) programme and the withdrawal of the US from the ABM treaty of on space militarization. 相似文献
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