Limiting survival functions of self‐similar structures

We show the existence of a unique analytic single parameter limiting survival function arising from the repeated composition of a coherent structure as the number of components tends to infinity. Examples include the repeated composition process of the bridge structure. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

Robustness of efficient server assignment policies to service time distributions in finite‐buffered lines

We study the assignment of flexible servers to stations in tandem lines with service times that are not necessarily exponentially distributed. Our goal is to achieve optimal or near‐optimal throughput. For systems with infinite buffers, it is already known that the effective assignment of flexible servers is robust to the service time distributions. We provide analytical results for small systems and numerical results for larger systems that support the same conclusion for tandem lines with finite buffers. In the process, we propose server assignment heuristics that perform well for systems with different service time distributions. Our research suggests that policies known to be optimal or near‐optimal for Markovian systems are also likely to be effective when used to assign servers to tasks in non‐Markovian systems. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

The Randomization of Terrorist Attacks

The purpose of this article is to explore the economic theoretical foundations of the idea that rational terrorist organizations deliberately randomize their attacks (by type, timing, location, and targets) to generate uncertainty and intimidation. A choice theoretic framework is applied to the analysis of the terrorist organization's behavior to determine whether welfare (utility) gains from the randomization of terrorist attacks are plausible and feasible. The randomization of attacks can appear to promise higher amounts of political influence for each resource input but it turns out that randomization cannot manufacture a situation where higher amounts of political influence are obtained for each resource input.The results imply that, rather than randomization and instability, the rational terrorist organization is more likely to prefer stability. The findings and implications provide a theoretical explanation for the non-randomness of terrorist attacks.Thismay be one small step towards explaining the patterns – non-randomness – in the time-series of terrorist incidents.     

An engagement model to optimize defense against a multiple attack assuming perfect kill assessment

We present an air-defense engagement model to counter an attack by multiple antiship missiles, assuming perfect kill assessment. In this model, the probability of shooting down all incoming missiles is maximized. A generating function is employed to produce an algorithm which is used to evaluate the outcomes. © 1997 John Wiley & Sons, Inc. Naval Research Logistics 44: 687–697, 1997     

Replicated batch means for steady‐state simulations

This paper studies a new steady‐state simulation output analysis method called replicated batch means in which a small number of replications are conducted and the observations in these replications are grouped into batches. This paper also introduces and compares methods for selecting the initial state of each replication. More specifically, we show that confidence intervals constructed by the replicated batch means method are valid for large batch sizes and derive expressions for the expected values and variances of the steady‐state mean and variance estimators for stationary processes and large sample sizes. We then use these expressions, analytical examples, and numerical experiments to compare the replicated batch means method with the standard batch means and multiple replications methods. The numerical results, which are obtained from an AR(1) process and a small, nearly‐decomposable Markov chain, show that the multiple replications method often gives confidence intervals with poorer coverage than the standard and replicated batch means methods and that the replicated batch means method, implemented with good choices of initialization method and number of replications, provides confidence interval coverages that range from being comparable with to being noticeably better than coverages obtained by the standard batch means method. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

On the normality and abnormality of offsets obligations

Defence offsets have often been described as government‐to‐business compensation arrangements or contracts involving “reciprocity beyond that associated with normal market exchange”. This paper argues that it is irrelevant and misleading to use this notion as a criterion for defining offsets.

The paper also explores the apparent inconsistency between the maximising efficiency in defence procurement and the application of offsets requirements. It is shown that defence offsets are a subset of all the price‐quality‐quantity trade‐offs which in general characterise negotiations surrounding complex transactions.

It is argued that although reciprocal or offsetting arrangements are a normal aspect of commercial transacting, the operation of certain offsets schemes namely mandatory offsets obligations, may inhibit the buyer's flexibility in negotiating deals and result in inefficient procurement. This leads us to ask why these offsets schemes have persisted for so long.     

The German arms industry in a European context: A study in successful downsizing

Defence offsets rank as one of the most important and controversial topics within the broad field of defence economics. Arms vendors are likely to view offsetting investment as a distraction, fearful of its potential to hurt the bottom line. By contrast, policymakers in the arms purchasing countries see offsets as an opportunity to extract technology transfer, as well as employment, investment and export sales opportunities. Establishing the actual impact of offsets, however, is not easy. The subject is shrouded in secrecy and myth, with anecdote and generalisation pervading even the intellectual press. This paper seeks to break the mould by offering an empirical case study of the role of offsets in Malaysian defence industrialisation.