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251.
252.
基于神经网络的超精密机床伺服进给非线性模型辨识 总被引：1，自引：0，他引：1
以双轴Ｔ型结构的超精密金刚石车床的伺服进给系统为研究对象,采用自构造神经网络技术,建立了系统的非线性动态数学模型,为系统非线性控制与补偿提供参考模型 相似文献
253.
Reid B. C. Pauly 《The Nonproliferation Review》2013,20(3-4):441-455
ABSTRACTThis article explores how two influential American policy makers—Paul Nitze and McGeorge Bundy—wrestled with the idea of a norm against the use of nuclear weapons. Existing scholarship has overlooked how both Bundy and Nitze came to understand the idea of nuclear non-use, especially related to the credibility of threats to use nuclear weapons. Using documentary evidence from their personal papers, this article illuminates the thinking of Bundy and Nitze, finding that both engaged with the idea of a norm of non-use of nuclear weapons in their strategic writing and thought. 相似文献
254.
Pakistan confronts numerous domestic security challenges including jihadist extremism, Sunni-Shi'a sectarian violence, drug trafficking, illegal commodity smuggling, endemic corruption, and systemic problems with the provision of justice and law enforcement. While much has been written about US military assistance to the Government of Pakistan (GOP) and the ever-evolving political relations between the two countries, basic questions of highest policy significance related to Pakistan's internal security have never been fully studied or considered. This essay begins to address these empirical lacunae. It first provides a comprehensive examination of Pakistan's internal security environment and the effectiveness of the GOP's criminal justice structures in dealing with these challenges. The paper then goes on to assess the impact and utility of the current suite of US law enforcement assistance in helping to fortify Pakistan's domestic security environment. The study raises a number of difficult questions pertinent to the long-term impact of this support, particularly in terms of its effect on fostering a viable, accountable and transparent system of civilian governance and policing. 相似文献
255.
Did the Panamanian Defense Forces conduct infiltration operations at the Arraijan Tank Farm in 1988?
William Yaworsky 《Small Wars & Insurgencies》2013,24(3):456-473
This article reviews the circumstances surrounding a relatively obscure and almost forgotten US Marine Corps and Army security enhancement operation undertaken in Panama that commenced in early April of 1988. Marines were sent to Panama to protect oil and ammunition storage facilities from potential saboteurs. By April 1989 they had reported sighting armed, uniformed intruders on at least 43 occasions and receiving gunfire or discharging their own weapons during 16 incidents. Yet despite the repeated barrages of small arms fire over the course of a year, they failed to recover enemy ammunition, bodies or body parts and their own equipment and positions displayed no signs of suffering from hostile fire. This article analyzes the events from the point of view of a veteran of the operation and highlights the role that psychological operations may have played in generating the situation. 相似文献
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257.
Using the ITERATE dataset, we explore the origins of transnational terrorist activity, from 1982 through 1997, in 118 countries. We model terrorism, not as a function of a nation’s ethnic, religious or linguistic fractionalization, but as an independent measure of perceived ethnic tensions. When we control for institutional quality, evidence that political rights and civil liberties mitigate the terrorism‐producing effects of ethnic tensions exists only since 1990. Economic freedoms, on the other hand, robustly reduce the number of terrorist attacks originating in ethnically tense societies. 相似文献
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259.
There are conflicting views as to the relationship between a nation’s defense expenditure (DE) and its population’s income inequality (INEQ). DE, always an important part of government budget, can easily crowd out transfer payments, necessary to improve INEQ; however, these payments may also create a demand that may raise the income levels of the lower income earners. Consequently, the relationship between DE and INEQ is an important question. This paper examines the relationship between DE and INEQ in China for the period of 1989–2012. Utilizing basic cointegration and causality tests, our objective is to add to the literature by providing evidence that China’s DE, in fact, do have an impact on INEQ. 相似文献
260.
We consider a queueing system with batch Poisson arrivals subject to disasters which occur independently according to a Poisson process but affect the system only when the server is busy, in which case the system is cleared of all customers. Following a disaster that affects the system, the server initiates a repair period during which arriving customers accumulate without receiving service. The server operates under a Multiple Adapted Vacation policy. The stationary regime of this process is analyzed using the supplementary variables method. We obtain the probability generating function of the number of customers in the system, the fraction of customers who complete service, and the Laplace transform of the system time of a typical customer in stationarity. The stability condition for the system and the Laplace transform of the time between two consecutive disasters affecting the system is obtained by analyzing an embedded Markov renewal process. The statistical characteristics of the batches that complete service without being affected by disasters and those of the partially served batches are also derived. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 171–189, 2015 相似文献