Strategic Defense and Attack for Series and Parallel Reliability Systems: Reply to Rejoinder

Kovenock and Roberson's (2012a, b) replication of Hausken’s (2008a) equations and parameter restrictions do not enhance our insight into the defense and attack of reliability systems. This reply intends to fill the remaining understanding gaps.     

SECURITY GOVERNANCE IN SOUTH AFRICA

In the ten years since the establishment of South Africa's first inclusive democratic government, an ambitious, extensive and systematic process of reform has been carried out in the governance of security. The process is widely regarded as having been successful and a model for other processes of ‘security sector reform’ in the context of transitions from authoritarian forms of governance to democratic ones.

That this been achieved with hardly a shot fired in anger is a remarkable achievement and a credit to visionary political leadership as well as organisational capacity, in other words to effective security governance.

At the same time, progress has been uneven and sometimes fragmentary, policy intentions and commitments have not always been translated into practice, the end results have not been to everyone's liking, and transformation has engendered its own pathologies. Thus several challenges remain in improving security governance.

This article provides a broad overview of the roles played by the various actors in the governance of the security sector, including the executive, parliament and civil society. It examines the main policy frameworks and touches on organisational transformation, because it is impossible to deal with governance in isolation from these issues. Policy processes and the frameworks they give rise to—in particular—are critical for effective governance. This article deals with the defence, safety and security and intelligence fields. A comprehensive overview would need to include the governance of criminal justice and foreign policy. The article does not seek to make an overall evaluation of governance, but to identify achievements, shortfalls and challenges.     

COOPERATION,SIGNALS, AND SANCTIONS

This paper uses game theory and modeling to address the role of incentive structures and information dynamics in nuclear inspections. The traditional argument is that compliant states should be willing to allow inspections to prove their innocence, while proliferating states are likely to impede inspections. This argument does not take into account the historical variation in inspection, signaling, and sanctioning behaviors. Using a game theoretic analysis and model, it is shown that the separation of proliferators from nonproliferators only occurs when the likelihood of proliferation is high and punishment costs are moderate. The model assumes that states can choose how much to cooperate with inspectors and must pay opportunity or secrecy costs when inspections are effective. The results are tested against a set of real-life cases, providing support for the claims of historical variation and the model's deductive propositions.     

A three‐stage procurement optimization problem under uncertainty

This article examines a problem faced by a firm procuring a material input or good from a set of suppliers. The cost to procure the material from any given supplier is concave in the amount ordered from the supplier, up to a supplier‐specific capacity limit. This NP‐hard problem is further complicated by the observation that capacities are often uncertain in practice, due for instance to production shortages at the suppliers, or competition from other firms. We accommodate this uncertainty in a worst‐case (robust) fashion by modeling an adversarial entity (which we call the “follower”) with a limited procurement budget. The follower reduces supplier capacity to maximize the minimum cost required for our firm to procure its required goods. To guard against uncertainty, the firm can “protect” any supplier at a cost (e.g., by signing a contract with the supplier that guarantees supply availability, or investing in machine upgrades that guarantee the supplier's ability to produce goods at a desired level), ensuring that the anticipated capacity of that supplier will indeed be available. The problem we consider is thus a three‐stage game in which the firm first chooses which suppliers' capacities to protect, the follower acts next to reduce capacity from unprotected suppliers, and the firm then satisfies its demand using the remaining capacity. We formulate a three‐stage mixed‐integer program that is well‐suited to decomposition techniques and develop an effective cutting‐plane algorithm for its solution. The corresponding algorithmic approach solves a sequence of scaled and relaxed problem instances, which enables solving problems having much larger data values when compared to standard techniques. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Should competing firms reveal their capacity?

In this article, we explore when firms have an incentive to hide (or reveal) their capacity information. We consider two firms that aim to maximize profits over time and face limited capacity. One or both of the firms have private information on their own capacity levels, and they update their beliefs about their rival's capacity based on their observation of the other firm's output. We focus on credible revelation mechanisms—a firm may signal its capacity through overproduction, compared to its myopic production levels. We characterize conditions when high‐capacity firms may have the incentive and capability to signal their capacity levels by overproduction. We show that prior beliefs about capacity play a crucial, and surprisingly complex, role on whether the firm would prefer to reveal its capacity or not. A surprising result is that, despite the fact that it may be best for the high‐capacity firm to overproduce to reveal its capacity when capacity information is private, it may end up with more profits than if all capacity information were public knowledge in the first place. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Efficient distributions of arms‐control inspection effort

A rule that constrains decision‐makers is enforced by an inspector who is supplied with a fixed level of inspection resources—inspection personnel, equipment, or time. How should the inspector distribute its inspection resources over several independent inspectees? What minimum level of resources is required to deter all violations? Optimal enforcement problems occur in many contexts; the motivating application for this study is the role of the International Atomic Energy Agency in support of the Treaty on the Non‐Proliferation of Nuclear Weapons. Using game‐theoretic models, the resource level adequate for deterrence is characterized in a two‐inspectee problem with inspections that are imperfect in the sense that violations can be missed. Detection functions, or probabilities of detecting a violation, are assumed to be increasing in inspection resources, permitting optimal allocations over inspectees to be described both in general and in special cases. When detection functions are convex, inspection effort should be concentrated on one inspectee chosen at random, but when they are concave it should be spread deterministicly over the inspectees. Our analysis provides guidance for the design of arms‐control verification operations, and implies that a priori constraints on the distribution of inspection effort can result in significant inefficiencies. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

OODA-L模式下的智能无人集群作战仿真建模框架

介绍了智能无人集群作战的相关概念,为反映智能无人仿真实体的自主能力和适应能力,提出将学习过程显性化的观察-判断-决策-行动-学习(Observe, Orient, Decide, Act and Learning, OODA-L)模式,并进一步扩展为适用于集群协同的Co-OODA-L模式。在智能无人仿真实体的总体描述上,采用马尔可夫决策过程进行数学抽象处理,提出智能无人Agent的三域分层结构。为体现智能无人集群作战的自主协同、分布式等特点,提出了利用人工神经网络将可变数量的智能无人Agent融合为同构或异构集群进行协同作战建模的体系结构。     

基于满意决策的多UAV协同目标分配方法

目标分配是UAV自主控制的重要问题。提出了基于满意决策的多UAV协同的目标分配技术,为解决多UAV协同的目标分配问题和多机场起飞的UAV编队配置问题提供了一种新颖而有效的方法。重点对其中的满意集计算、联合满意度、拒绝度和选择度的建立和计算等关键问题进行了讨论。以压制敌防空火力任务为背景对该方法进行了仿真,并将本文提出的方法和其他方法做了比较,仿真结果表明基于满意决策的多UAV协同的目标分配方法在效率上有明显优势。     

边防专业英语教学中存在的问题及对策

边防专业英语自身的特点和目前专业英语教学中面临的实际问题值得关注,改革边防专业英语教学,重视专业特色语言的教学,应采用任务式和讨论式教学来平衡学生的输入与输出,采用合作学习方式,注重学生的个性发展,培养复合型人才。