The reliability of a series system of repairable subsystems: A bayesian approach

Consider the problem of estimating the reliability of a series system of (possibly) repairable subsystems when test data and historical information are available at the component, subsystem, and system levels. Such a problem is well suited to a Bayesian approach. Martz, Waller, and Fickas [Technometrics, 30 , 143–154 (1988)] presented a Bayesian procedure that accommodates pass/fail (binomial) data at any level. However, other types of test data are often available, including (a) lifetimes of nonrepayable components, and (b) repair histories for repairable subsystems. In this article we describe a new Bayesian procedure that accommodates pass/fail, life, and repair data at any level. We assume a Weibull model for the life data, a censored Weibull model for the pass/fail data, and a power-law process model for the repair data. Consequently, the test data at each level can be represented by a two-parameter likelihood function of a certain form, and historical information can be expressed using a conjugate family of prior distributions. We discuss computational issues, and use the procedure to analyze the reliability of a vehicle system. © 1994 John Wiley & Sons, Inc.     

PEACEKEEPERS AS PERPETRATORS OF ABUSE

I am afraid there is clear evidence that acts of gross misconduct have taken place. This is a shameful thing for the United Nations to have to say, and I am absolutely outraged by it.

—Kofi Annan, United Nations Secretary-General

Despite promulgating a comprehensive set of guidelines to deter UN personnel from committing acts of sexual misconduct, allegations of sexual exploitation and abuse have become widespread within United Nations peacekeeping missions. The policy of zero-tolerance for peacekeeper misconduct has not been matched by strong disciplinary measures, and crimes are often ignored and rarely punished: absentee fathers, rapists and murderers simply disappear back in their home countries. In countries where women and children rarely have the same economic resources, political rights and authority or control over their environment—or their bodies—they easily become prey for those in perceived positions of power and authority. By failing to hold those responsible to account, the UN may in fact be fuelling even greater discrimination and violence against women and children. In order to ensure those who are mandated to protect to do not become perpetrators of abuse, the UN must take a stronger stand against those who commit acts of sexual misconduct, and must ensure that victims see that their abuser is brought to justice and that reparation is offered. A recent report submitted by the Secretary-General's Special Envoy on Sexual Exploitation and Sexual Abuse makes a comprehensive set of recommendations to prevent, detect, and respond to these allegations. The aim of this essay is to highlight some of the main points of the Special Envoy's report, and to examine the practical challenges the UN and troop/police contributing countries will face when attempting to implement these recommendations.     

Coalitions & the Legitimisation of UK Security Policy

Abstract

David Moore analyses the role of the Treasury in detemining and controlling defence policy and expenditure, and the place of the MoD within this function.     

People's War? Self-Interest,Coercion and Ideology in Nepal's Maoist Insurgency

This paper analyses the micro-level processes by which ordinary rural Nepalis came to support the Maoist insurgency. Working through the implications of orthodox collective action theory, it finds that Maoist cadres are unlikely to have been strongly motivated by considerations of acquisitive self-interest. However, the participation of many may have been partly secured through various forms of coercion. Non-instrumental motivations for participation that are not accounted for by the rational choice premises that underpin conventional collective action theory are also identified. These are found to have been of particular significance in the violent and uncertain context of contemporary Nepal.     

Defense spending and the macroeconomy

Given Kinsella's (1990, 1991) appeal for analysis to be pursued using sub‐annual level of data, we pursue such an endeavor in this paper. We examime the effect of defence spending on real output, the unemployment rate, price level, and interest rate covering a quarterly time frame 1960:1 to 1988:1 using an unrestricted vector autoregression framework. Our results parallel the findings of Kinsella in that there appears no causal relationship in either direction between defence spending and economic performance.     

INTEGRATING NUCLEAR WEAPONS STOCKPILE MANAGEMENT AND NUCLEAR ARMS CONTROL OBJECTIVES TO ENABLE SIGNIFICANT STOCKPILE REDUCTIONS

In his 2009 Prague speech and the 2010 Nuclear Posture Review, President Barack Obama committed the United States to take concrete steps toward nuclear disarmament while maintaining a safe, secure, and effective nuclear deterrent. There is an inherent tension between these two goals that is best addressed through improved integration of nuclear weapons objectives with nuclear arms control objectives. This article reviews historical examples of the interaction between the two sets of objectives, develops a framework for analyzing opportunities for future integration, and suggests specific ideas that could benefit the nuclear weapons enterprise as it undergoes transformation and that could make the future enterprise compatible with a variety of arms control futures.     

The Importance of Safeguards Culture

International safeguards is the system of measures put in place by the International Atomic Energy Agency and states to ensure nuclear programs remain dedicated to peaceful purposes. This international safeguards system consists of agreements, inspections, and evaluations that have never considered the safeguards culture of a state or facility. Neither a common definition nor an understanding of safeguards culture is internationally recognized. This article provides an analysis of the concept of safeguards culture and gauges its value to the international safeguards community. The authors explore distinctions among safeguards culture, safeguards compliance, and safeguards performance, and suggest possible indicators of safeguards culture and methods to promote a strong, positive safeguards culture.