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21.
This study analyses the performance of the productivity of the main industrial subsectors composing the security and defence technological and industrial base (SDTIB) in Spain from 1996 to 2009. Accordingly, we have used the non-parametric data envelopment analysis and bootstrapping techniques to compute Malmquist productivity indexes that allow us to split productivity growth into efficiency change and technical progress. The results obtained show productivity improvement in the SDTIB as a whole due mainly to advances in technology and to a lesser extent to the contribution of technical efficiency. The bootstrap approach yields further evidence, as for many cases, productivity growth or decline, is not statistically significant. This is the first time a study of this kind has been carried out on the production process of this sector in Spain.  相似文献   
22.
The article discusses the disconnect between arms control and disarmament practices vis-à-vis peacebuilding practices. It critically analyzes Disarmament, Demobilization, and Reintegration (DDR) practices focusing on their absence of dialogue with international arms control and disarmament (ACD) practices. It proposes that a conversation between experts involved in these distinct practices could promote a political discussion on the place of weapons held by state and non-state actors in times of peace. The argument is illustrated through an analysis of the treatment of rules on weapons in the Colombian peace process (2012–present) with the Revolutionary Armed Forces of Colombia (FARC). The article concludes that the disconnect between the arms control and disarmament and the peacebuilding associations, as seen in the context of DDR practices, reinstates the rule on the monopoly of violence by the state, preventing a broader discussion of the role of weapons and violence in the building of political communities.  相似文献   
23.
Strategic studies deals intimately with the topic of power. Most scholars in the discipline work with a concept of power as an adversarial zero-sum competition. This is natural and necessary. However, other conceptions of power developed within political science and sociology could enrich strategic studies. Approaching two typical, traditional tasks of strategy – alliance building and war-fighting – this article demonstrates the heuristic mileage of theories of collective power. In particular, we can shed new light on the post-Cold War transformation of NATO as well as state-building as a strategy in counter-insurgencies with new ideas of power. Broadening the palette of theories of power is thus valuable if strategic studies is to prosper as an independent field of study.  相似文献   
24.
We explore the economic and environmental impacts of market structures (competition or integration at vertical and horizontal levels). We consider a bilateral duopoly consisting of two manufacturers and two retailers in which each manufacturer offers a wholesale price contract to the respective retailer. The manufacturers decide on wholesale prices and abatement efforts concerning pollution emissions related to manufacturing processes, whereas the retailers compete in quantities in the consumer market. To understand the comprehensive effects of market structures on economic competitiveness and environmental sustainability, we examine a measure of eco‐friendly social welfare, which is the ratio of social welfare and environmental pollution. Interestingly, we find that the market structures that have been believed to be more efficient are less efficient from a broader perspective: (1) double marginalization can generate higher eco‐friendly social welfare, and (2) horizontal competition between firms can result in lower eco‐friendly social welfare. Although vertical integration and horizontal competition yield greater social welfare by facilitating more production activities, these market structures often fail to induce sufficient abatement efforts to balance the polluting effect of the large volume, resulting in more significant environmental degradation. We also show that, despite the pollution‐curbing effect, higher emission penalties can result in less eco‐friendly social welfare. They can even curtail the abatement efforts of firms under particular circumstances. When products become more substitutable, the eco‐friendly social welfare can decrease depending upon the market structure.  相似文献   
25.
Over the last two decades, a number of countries (most notably China, Russia and Iran) have been developing so-called anti-access and area denial (A2/AD) capabilities, such as ballistic and cruise missiles, offensive cyber-weapons, electronic warfare, etc. The development of A2/AD capabilities by non-Western countries undermines the foundations of US power projection and global military-technological supremacy. In order to overcome, or at least mitigate, the impending A2/AD challenge, the US Department of Defense (DoD) began to roll out its so-called ‘third’ offset strategy in late 2014. The strategy aims to bring about innovative operational concepts and technologies and spur new doctrinal and organisational debates. This article assesses which of the operational concepts and capabilities informing current US discussions on offset may be relevant in the context of the A2/AD challenges Europeans face on their eastern ‘flank‘ and in their ‘extended southern neighbourhood‘, and which may not. Europeans must grapple with the same conceptual puzzle as the US: how to strike the right balance between defeating A2/AD capabilities and hedging against them, i.e. through alternative strategies that are less dependent on unhindered access and resort to asymmetric forms of warfare. However, they must take into account the geographical features of their eastern flank and extended southern neighbourhood, the level of technological maturity of their challengers, and their own military-technological prowess and political limitations. This suggests a somewhat different approach to offsetting A2/AD than that adopted by the US.  相似文献   
26.
We study optimal pricing for tandem queueing systems with finite buffers. The service provider dynamically quotes prices to incoming price sensitive customers to maximize the long-run average revenue. We present a Markov decision process model for the optimization problem. For systems with two stations, general-sized buffers, and two or more prices, we describe the structure of the optimal dynamic pricing policy and develop tailored policy iteration algorithms to find an optimal pricing policy. For systems with two stations but no intermediate buffer, we characterize conditions under which quoting either a high or a low price to all customers is optimal and provide an easy-to-implement algorithm to solve the problem. Numerical experiments are conducted to compare the developed algorithms with the regular policy iteration algorithm. The work also discusses possible extensions of the obtained results to both three-station systems and two-station systems with price and congestion sensitive customers using numerical analysis.  相似文献   
27.
Abstract

Typically, when analysing contemporary Russian–Chechen conflicts, the relegation of the nationalist struggle to a secondary role by the religious battle waged by the North Caucasus insurgency is pinpointed as one of the fundamental differences between the First and Second War in Chechnya. This article discusses how it was reflected in one of the most important media of the Chechen Islamist insurgency: the Kavkaz Center. To this end, 2859 English language news items posted on the website during 2001–04 were reviewed using media frame analysis.  相似文献   
28.
We present two random search methods for solving discrete stochastic optimization problems. Both of these methods are variants of the stochastic ruler algorithm. They differ from our earlier modification of the stochastic ruler algorithm in that they use different approaches for estimating the optimal solution. Our new methods are guaranteed to converge almost surely to the set of global optimal solutions under mild conditions. We discuss under what conditions these new methods are expected to converge faster than the modified stochastic ruler algorithm. We also discuss how these methods can be used for solving discrete optimization problems when the values of the objective function are estimated using either transient or steady‐state simulation. Finally, we present numerical results that compare the performance of our new methods with that of the modified stochastic ruler algorithm when applied to solve buffer allocation problems. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.  相似文献   
29.
We present two frameworks for designing random search methods for discrete simulation optimization. One of our frameworks is very broad (in that it includes many random search methods), whereas the other one considers a special class of random search methods called point‐based methods, that move iteratively between points within the feasible region. Our frameworks involve averaging, in that all decisions that require estimates of the objective function values at various feasible solutions are based on the averages of all observations collected at these solutions so far. Also, the methods are adaptive in that they can use information gathered in previous iterations to decide how simulation effort is expended in the current iteration. We show that the methods within our frameworks are almost surely globally convergent under mild conditions. Thus, the generality of our frameworks and associated convergence guarantees makes the frameworks useful to algorithm developers wishing to design efficient and rigorous procedures for simulation optimization. We also present two variants of the simulated annealing (SA) algorithm and provide their convergence analysis as example application of our point‐based framework. Finally, we provide numerical results that demonstrate the empirical effectiveness of averaging and adaptivity in the context of SA. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012  相似文献   
30.
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