基于失效树的某型无坐力炮弹储存可靠性分析

通过对某型无坐力炮弹战斗部的结构分析和功能分析,以弹着目标不爆炸为顶事件建立了失效树,并根据该型弹药的功能构件在储存期间的特点选择了失效树的简化原则,建立了系统可靠度模型。确定了由储存因素导致弹着目标不爆炸这一事件的4种主要失效模式。并通过分析其不同的储存期失效机理和影响因素,提出该型炮弹的储存策略。     

Europe,Russia and the Ukraine crisis: the dynamics of coercion

This article analyses European strategy towards Russia during the Ukraine crisis between February 2014 and December 2015, conceptualising it as a coercive diplomatic strategy and analysing the relationship between its ends, ways and means. European strategy sought to reverse Russian intervention. However, this overarching aim was flanked by two ‘constraining’ aims of avoiding an escalation of the conflict and a breakdown of relations with Russia. The strategy shifted between these aims, which proved to be irreconcilable: while the EU partly succeeded in containing the conflict, it failed to reverse Russian intervention and relations between the EU and Russia deteriorated sharply.     

Periodic review inventory management with contingent use of two freight modes with fixed costs

We study a stochastic inventory model of a firm that periodically orders a product from a make‐to‐order manufacturer. Orders can be shipped by a combination of two freight modes that differ in lead‐times and costs, although orders are not allowed to cross. Placing an order as well as each use of each freight mode has a fixed and a quantity proportional cost. The decision of how to allocate units between the two freight modes utilizes information about demand during the completion of manufacturing. We derive the optimal freight mode allocation policy, and show that the optimal policy for placing orders is not an (s,S) policy in general. We provide tight bounds for the optimal policy that can be calculated by solving single period problems. Our analysis enables insights into the structure of the optimal policy specifying the conditions under which it simplifies to an (s,S) policy. We characterize the best (s,S) policy for our model, and through extensive numerical investigation show that its performance is comparable with the optimal policy in most cases. Our numerical study also sheds light on the benefits of the dual freight model over the single freight models. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

Technical note: Finite-time regret analysis of Kiefer-Wolfowitz stochastic approximation algorithm and nonparametric multi-product dynamic pricing with unknown demand

We consider the problem of nonparametric multi-product dynamic pricing with unknown demand and show that the problem may be formulated as an online model-free stochastic program, which can be solved by the classical Kiefer-Wolfowitz stochastic approximation (KWSA) algorithm. We prove that the expected cumulative regret of the KWSA algorithm is bounded above by where κ₁, κ₂ are positive constants and T is the number of periods for any T = 1, 2, … . Therefore, the regret of the KWSA algorithm grows in the order of , which achieves the lower bounds known for parametric dynamic pricing problems and shows that the nonparametric problems are not necessarily more difficult to solve than the parametric ones. Numerical experiments further demonstrate the effectiveness and efficiency of our proposed KW pricing policy by comparing with some pricing policies in the literature.     

A Good Ally - Norway and International Statebuilding in Afghanistan, 2001-2014

The article examines the findings of the Commission of Inquiry established by the Norwegian government in 2014 to evaluate all aspects of Norway’s civilian and military contribution to the international operation in Afghanistan from 2001 to 2014. Concerned with the wider implications of the Commission’s findings, it focuses on two issues in particular: (1) Norway’s relations with the US, a close and long-standing strategic ally whose resources, capabilities and dominance of decision-making dwarfed that of all other coalition partners in Afghanistan; and (2) Norway’s record in the province of Faryab, where, from 2005 to 2012, a Norwegian-led Provincial Reconstruction Team was charged with bringing security, good governance and development to the province. How Norway prioritised and managed relations with the US highlights and helps to problematise the challenges – political, practical and moral – facing small and medium-sized powers operating in a coalition alongside the US. Norwegian efforts in Faryab are revealing of the dilemmas and contradictions that plagued and, ultimately, fatally undermined the international intervention as a whole. As such, Norway’s experience provides a microcosm through which the inherent limitations of the attempt to transfer the structures of modern statehood and Western democracy to Afghanistan can be better understood.     

The practice of strategy: South African defence in stasis

The article concerns the strategy development processes of the South African Department of Defence in South Africa. It intends to identify the probable causes of the observed failure of the South African National Defence Force to develop appropriate departmental policy and military strategy. Military strategy comprises force development, force employment, force deployment and the coordination of these elements in pursuit of national, grand-strategic objectives. (See Dennis M. Drew and Donald M. Snow, Making Twenty-first Century Strategy: An Introduction to Modern National Security Processes and Problems Montgomery, AL: Air University Press, Maxwell Air Force Base, November 2006, 103). Of these four constructs, the article concerns itself only with the first two. The article analyses two complementary approaches to strategy formation: a resource-driven, inside-out model and an interests-driven, outside-in method. The article concludes that the Department is preoccupied with the inside-out method to the lasting detriment of the declared strategic intent of the defence policy.     

谈外国旅游团来琼免签政策实施的不足与完善

外国旅游团来琼免签政策是目前我国实施时间最长、最宽松的区域性免签便利政策。阐述了外国旅游团来琼免签政策沿革演变历程,从入出境管理和边防检查的角度分析了其施行过程中存在的不足与原因,提出了完善免签政策的措施。     

The NBUL class of life distribution and replacement policy comparisons

Let X and X_τ denote the lifetime and the residual life at age τ of a system, respectively. X is said to be a NBUL random variable if X_τ is smaller than X in Laplace order, i.e., X_τ ≤_L X. We obtain some characterizations for this class of life distribution by means of the lifetime of a series system and the residual life at random time. We also discuss preservation properties for this class of life distribution under shock models. Finally, under the assumption that the lifetimes have the NBUL property, we make stochastic comparisons between some basic replacement policies. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 578–591, 2001.     

A theory of war economies

This article presents a proposed theory of how war economies are formed and maintained, as well as an integrated policy framework to guide the dismantling of war economies emanating from the proposed theory. Additionally, six potential areas for future research pertaining to the dismantling of war economies are also presented.     

The management of security incidents by private security

This article is about the management of security incidents in organisations and companies which are under the protection of private security personnel, whether in-house or contracted. Incidents can be defined as accidental or anecdotal (bird flies into a camera) to a violation of law or company policy. Managing security incidents is one of the key functions of a private security service provider. The purpose of this study is to explore the management of security incidents and the information related thereto, identify shortcomings and find solutions for managing these shortcomings. Interviews were used to gain insight from personnel within the private and government sectors which are served by the private security industry. It was found that security incidents are handled in a routine way by organisations from the different sectors. One major shortcoming is that security incidents and the information related thereto are not managed by security service providers according to an operational framework or model with the required infrastructure and resources. The significance of this study is for security incidents to be managed correctly, so that the information related thereto may be captured accurately, analysed and used proactively and reactively to improve physical protection systems, develop preventative strategies and provide actionable information products in order to reduce crime, increase detection rates and prevent losses.