Robust preallocated preferential defense

The problem is to protect a set of T identical targets that may come under attack by A identical weapons. The targets are to be defended by D identical interceptors, which must be preallocated to defend selected targets. The attacker is aware of the number of interceptors, but is ignorant of their allocation. The size of the attack is chosen by the attacker from within a specified range. The robust strategies developed in this article do not require the defender to assume an attack size. Rather, the defender chooses a strategy which is good over a wide range of attack sizes, though not necessarily best for any particular attack size. The attacker, knowing that the defender is adopting a robust strategy, chooses the optimal attack strategy for the number of weapons he chooses to expend. The expected number of survivors is a function of the robust defense strategy and optimal attack strategy against this robust defense.     

Measuring information in right-censored models

The theory of majorization is used to develop measures of information in the randomly right-censored model when the lifetime and censoring variables are discrete. Majorization also enables us to prove some basic theorems about the measures in a simple and unified fashion. These measures include Shannon's information as a special case. The measures are inadequate in the continuous case and some alternative measures, based on the variance of the lifetime random variable, are proposed.     

A branch and bound algorithm for computing optimal replacement policies in consecutive k‐out‐of‐n‐systems

This paper presents a branch and bound algorithm for computing optimal replacement policies in a discrete‐time, infinite‐horizon, dynamic programming model of a binary coherent system with n statistically independent components, and then specializes the algorithm to consecutive k‐out‐of‐n systems. The objective is to minimize the long‐run expected average undiscounted cost per period. (Costs arise when the system fails and when failed components are replaced.) An earlier paper established the optimality of following a critical component policy (CCP), i.e., a policy specified by a critical component set and the rule: Replace a component if and only if it is failed and in the critical component set. Computing an optimal CCP is a optimization problem with n binary variables and a nonlinear objective function. Our branch and bound algorithm for solving this problem has memory storage requirement O(n) for consecutive k‐out‐of‐n systems. Extensive computational experiments on such systems involving over 350,000 test problems with n ranging from 10 to 150 find this algorithm to be effective when n ≤ 40 or k is near n. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 288–302, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10017     

The International Criminal Court and the Deterrence of Human Rights Atrocities

Research on human rights treaties has mostly reached depressingly similar conclusions – that such treaties and their resulting institutions have little or no impact on human rights. The International Criminal Court, however, possesses significant power to investigate and prosecute violations of international law that equip it with potentially more influence than previous human rights regimes. I suggest, however, that the impact of the ICC on human rights is conditioned by signatory governments’ commitment to good governance and acceptance of the role of the ICC in addressing violations of international law. I develop a two-stage model of ICC ratification and human rights abuse that shows that while many states have ratified the ICC Treaty, not all are committed to stopping the crimes under its jurisdiction. Rather, state commitment to human rights depends first on its commitment to the rule of law within its own borders. Second, commitment to human rights depends on states’ willingness to grant the ICC the powers necessary to carry out its mission. Through a number of statistical tests, I find strong support for these hypotheses on states’ human rights and propensity for violence.