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351.
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…Rapid indigenisation is the cornerstone of our policy of self-reliance India MoD Annual Report 1978–9
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We consider the integrated problem of optimally maintaining an imperfect, deteriorating sensor and the safety‐critical system it monitors. The sensor's costless observations of the binary state of the system become less informative over time. A costly full inspection may be conducted to perfectly discern the state of the system, after which the system is replaced if it is in the out‐of‐control state. In addition, a full inspection provides the opportunity to replace the sensor. We formulate the problem of adaptively scheduling full inspections and sensor replacements using a partially observable Markov decision process (POMDP) model. The objective is to minimize the total expected discounted costs associated with system operation, full inspection, system replacement, and sensor replacement. We show that the optimal policy has a threshold structure and demonstrate the value of coordinating system and sensor maintenance via numerical examples. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 399–417, 2017 相似文献
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Thomas A. Marks 《Small Wars & Insurgencies》2017,28(1):81-118
During the period 1996–2006, the Communist Party of Nepal (Maoist) waged overt people’s war to seize state power and institute a new order that realized the party’s understanding of ‘New Democracy’ as posited by Mao Tse-tung. Contextual shifts led to a crucial strategic turning point in September 2005, when the Maoists agreed to a united front with estranged legal parties to oust the monarchy and establish a republic. Though touted as acceptance of political reintegration, the move was tactical rather than strategic. The party had no intention of supporting a parliamentary version of democracy and thus, 2006–2016, engaged in a covert effort to seize power. Central to this effort was the paramilitary Young Communist League (YCL), the members of which responded to inflammatory party verbiage and exhortations with attacks upon rival political actors. These attacks, academically and legally, were terrorism and offered a salient illustration of intra-state unrestricted warfare. Ultimately, organizational, national, and regional circumstances caused the main Maoist movement to move decisively away from its covert approach. By that time, however, radical splinters had embraced the use of terrorism against rival political actors, creating a situation whereby local politics is yet a dangerous endeavor in certain areas and at certain times. 相似文献
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In 2013, the staff of the U.S. Nuclear Regulatory Commission estimated the reduction of the off-site economic losses from a fire in a drained U.S. spent fuel pool if fuel that had cooled for more than five years were transferred to dry cask storage—an option it called “expedited transfer.” In this article, it is shown that the savings would be much higher than the NRC estimated. Savings increase to about $2 trillion if: losses beyond 50 miles are included; the land-contamination threshold for long-term population relocation is changed to that used for the Chernobyl and Fukushima accidents and recommended by the U.S. Environmental Protection Agency; and, based on the experience of Japan, decontamination of land areas to levels acceptable for population return is assumed to take at least four years. If expedited transfer were implemented, the off-site economic losses would be reduced by about 98%. 相似文献
356.
On 22 September 1979 two optical sensors on U.S. satellite Vela 6911 detected a double-flash of light that appeared characteristic of an atmospheric nuclear explosion conducted over the southern Atlantic or Indian Ocean. It became known as the Vela Incident, Event 747, or Alert 747. An anomaly between the amplitude of the two signals during the second pulse led a U.S. government expert panel established to assess the event to conclude in mid-1980 that a more likely explanation was the impact of a small meteoroid on the satellite, the debris from which reflected sunlight into the sensors' field of view. No model was presented to support the contention, and a similar anomaly—known as background modulation—was a given for the second pulse of all confirmed explosions detected by Vela, though beginning later. Nonetheless, this event has remained the subject of intense debate. This article reviews the evidence and presents an updated analysis of the original Vela signal based on recently declassified literature and on modern knowledge of interplanetary dust and hyper velocity impact. Given the geometry of the satellite, and that the bulk of the surface comprised solar panels, much of the debris from any collision would be carried away from the sensors' field of view. Thus, a meteoroid collision appears much less likely than previously assumed. The double flash is instead consistent with a nuclear explosion, albeit detected by an aged satellite for which background modulation was abnormal and/or commenced earlier, also seen in post-event SYSTEM tests. A companion paper to be published in 2018 presents radionuclide and hydroacoustic evidence supporting the conclusion that the Vela Incident was a nuclear weapon test explosion. 相似文献
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Nathaniel L. Moir 《Small Wars & Insurgencies》2017,28(6):909-946
This article assesses Bernard Fall’s concept of Vietnamese Revolutionary Warfare in Indochina between 1953 and 1958. It also investigates differences in the conceptualization of Revolutionary Warfare between Fall and proponents of French military doctrine known as la guerre révolutionnaire. The last component of the article considers limits of Fall’s influence on counterinsurgency doctrine. 相似文献
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针对非线性非高斯导航系统信息处理问题,采用自组织算法、神经网络和遗传算法等改进传统非线性Kalman滤波算法,构建一种自适应的组合导航系统。应用具有冗余趋势项的自组织算法、Volterra神经网络和遗传算法,建立导航系统误差的非线性预测模型,进而计算得到其预测值;将该预测值与Kalman滤波算法求得的估计值进行比较得到差值,以此监测Kalman滤波算法的工作状态;采用自适应控制方法,在导航系统结构层面改进Kalman滤波算法,构建新型的导航系统误差补偿模型。开展基于导航系统KIND-34的半实物仿真研究,应用所提出的改进方法改善了导航系统误差的补偿效果,提高了组合导航系统的自适应能力和容错能力。 相似文献