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711.
Accelerated life testing (ALT) is commonly used to obtain reliability information about a product in a timely manner. Several stress loading designs have been proposed and recent research interests have emerged concerning the development of equivalent ALT plans. Step‐stress ALT (SSALT) is one of the most commonly used stress loadings because it usually shortens the test duration and reduces the number of required test units. This article considers two fundamental questions when designing a SSALT and provides formal proofs in answer to each. Namely: (1) can a simple SSALT be designed so that it is equivalent to other stress loading designs? (2) when optimizing a multilevel SSALT, does it degenerate to a simple SSALT plan? The answers to both queries, under certain reasonable model assumptions, are shown to be a qualified YES. In addition, we provide an argument to support the rationale of a common practice in designing a SSALT, that is, setting the higher stress level as high as possible in a SSALT plan. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2013 相似文献
712.
Data envelopment analysis (DEA) is a methodology for evaluating the relative efficiencies of peer decision‐making units (DMUs), in a multiple input/output setting. Although it is generally assumed that all outputs are impacted by all inputs, there are many situations where this may not be the case. This article extends the conventional DEA methodology to allow for the measurement of technical efficiency in situations where only partial input‐to‐output impacts exist. The new methodology involves viewing the DMU as a business unit, consisting of a set of mutually exclusive subunits, each of which can be treated in the conventional DEA sense. A further consideration involves the imposition of constraints in the form of assurance regions (AR) on pairs of multipliers. These AR constraints often arise at the level of the subunit, and as a result, there can be multiple and often inconsistent AR constraints on any given variable pair. We present a methodology for resolving such inconsistencies. To demonstrate the overall methodology, we apply it to the problem of evaluating the efficiencies of a set of steel fabrication plants. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013 相似文献
713.
Many authors contend that ethnic extremism coupled with political manipulation were the primary factors behind the Rwandan genocide. Yet, to oversimplify the cause of this tragedy makes one blind to the complicated nexus that generated the outcome. Even though this genocide was quick in its execution, the events that lead to this massacre took years to unfold. We argue that the evolution of human capital and the competition for scarce resources contributed to the genocide. 相似文献
714.
Sean M. Maloney 《Small Wars & Insurgencies》2013,24(1):27-44
Analytical focus on military operations in Iraq continue to overshadow analysis of the war in Afghanistan as it enters its sixth year. It is now possible to discern several clearly-delineated periods of coalition counterinsurgency and stabilization operations. What is the nature of the war and how has it evolved? Has there been success so far in Afghanistan? 相似文献
715.
Dennis M. Rempe 《Small Wars & Insurgencies》2013,24(3):24-61
In October 1959 the Eisenhower administration dispatched a CIA Special Team to survey the violence problem in Colombia. This article, part one of a two‐part series, examines this first significant attempt by a US administration to influence that nation's internal security situation. It investigates the Special Team's actions and analyses its recommendations for transforming Colombia's conventionally‐orientated security forces. The Team's survey, which focuses on counter‐insurgency tactics, civil action, intelligence operations, psychological warfare, and covert action, is the foundation from which Colombia's modern internal security structures are derived. 相似文献
716.
Christopher M. Faulkner Joshua E. Lambert Jonathan M. Powell 《Small Wars & Insurgencies》2013,24(3):641-659
ABSTRACTThis paper challenges recent claims that competitive market dynamics incentivize Private Military and Security Companies (PMSCs) to fully commit to providing effective services, thereby reducing the duration of civil war. Our assessment of a most-likely case scenario for this argument – Sierra Leone – reveals four critical problems. First, there is rarely direct competition, even if numerous companies are present. Second, the presence of multiple PMSCs usually represents a collaboration among subsidiaries providing distinct services, often under the same corporate umbrella. Third, data aggregation obfuscates the overlap of PMSC presence, inflating the amount of perceived competition. Finally, we raise concerns regarding how quantitative analyses can conflate conflict intensity with conflict termination. 相似文献
717.
A. S. Andreou ? K. E. Parsopoulos ? M. N. Vrahatis § G. A. Zombanakis 《Defence and Peace Economics》2013,24(5):481-495
The issue that this paper tackles is the assessment of the relative security benefits that Cyprus and Greece derive in the context of their cooperation on defence matters. This form of cooperation, known as the ‘Integrated Defence Space Doctrine’, aims at defending their interests in the Aegean Sea and the broader East Mediterranean theatre. The paper relies heavily on earlier research on this topic, which deals with the Greek–Cypriot alliance facing an arms race against Turkey, and uses a coefficient especially designed to assess the optimal levels of security and the associated defence expenditure of the two allies. A comparison of the relative security coefficient values for the two allies suggests that the security benefit that Greece derives thanks to its alliance with Cyprus exceeds the corresponding Cypriot benefit by far. Given the importance assigned to human resources by this index, in conjunction with the demographic problems of Greece, this conclusion justifies the recent Greek defence policy revision, emphasizing quality, capital equipment and flexibility of forces. This revision aims at satisfying the security requirements of the alliance and the increasing demands of an arms race against Turkey. 相似文献
718.
Michael D. Ward David Davis Mohan Penubarti Sheen Rajmaira Mali Cochran 《Defence and Peace Economics》2013,24(1):41-63
After a brief survey of the Indian economy, we survey the supply and demand of military expenditures in India over the last four decades. The causes of military expenditures appear to include regional rivalries and protracted conflicts, but it has proven difficult to delineate these with empirical models. The effects of military spending in India on economic growth appear to be benign, despite much speculation to the contrary. However, the opportunity costs of defence spending are shown to be considerable. We conclude with speculation about the role of debt and debt servicing in retarding future economic growth in India. We also speculate about the potential for the creation of a war economy in India. 相似文献
719.
Michael D. Cohen 《The Nonproliferation Review》2013,20(3):433-435
Conventional wisdom states that the stability-instability paradox does not explain the effect of nuclear proliferation on the conflict propensity of South Asia, and that nuclear weapons have had a different and more dangerous impact in South Asia than Cold War Europe. I argue that the paradox explains nuclear South Asia; that the similarities between nuclear South Asia and Cold War Europe are strong; and that conventional instability does not cause revisionist challenges in the long run. I develop and probe a psychological causal mechanism that explains the impact of nuclear weapons on Cold War Europe and South Asia. Following the ten-month mobilized crisis in 2002, Pakistani President Pervez Musharraf may have adopted a more moderate foreign policy toward India after experiencing fear of imminent nuclear war, as Soviet Premier Nikita Khrushchev did forty years earlier. I argue that the stability-instability paradox explains Cold War Europe and nuclear South Asia and will, conditional on Iranian and North Korean revisionism, predict the impact of nuclear weapon development on these states' conflict propensities. 相似文献
720.
Dennis M. Gormley 《The Nonproliferation Review》2013,20(2):123-139
ABSTRACTThe dangers and risks of employing a Conventional Prompt Global Strike (CPGS) capability greatly exceed the benefits. More suitable, if less prompt, alternatives exist to deal with fleeting targets. Even a niche CPGS capability—consisting of approximately twenty systems—carries risks, to say nothing of proposals to develop hundreds or more. Most dangerously, CPGS could stir the pre-emption pot, particularly vis-à-vis states that correctly perceive to be within the gunsights of US CPGS weapons; other states, too, may feel emboldened to emulate this US precedent and undertake their own form of prompt, long-range strike capability. Compressed circumstances surrounding such a scenario could foster unwanted erratic behavior, including the misperception that the threatening missile carries a nuclear weapon. But the true Achilles's heel of the CPGS concept is the unprecedented demands it places on the intelligence community to provide decision makers with “exquisite” intelligence within an hour timeframe. Such compressed conditions leave decision makers with virtually no time to appraise the direct—and potentially unintended—consequences of their actions. 相似文献