Life distribution analysis based on Lévy subordinators for degradation with random jumps

For a component or a system subject to stochastic degradation with sporadic jumps that occur at random times and have random sizes, we propose to model the cumulative degradation with random jumps using a single stochastic process based on the characteristics of Lévy subordinators, the class of nondecreasing Lévy processes. Based on the inverse Fourier transform, we derive a new closed‐form reliability function and probability density function for lifetime, represented by Lévy measures. The reliability function derived using the traditional convolution approach for common stochastic models such as gamma degradation process with random jumps, is revealed to be a special case of our general model. Numerical experiments are used to demonstrate that our model performs well for different applications, when compared with the traditional convolution method. More importantly, it is a general and useful tool for life distribution analysis of stochastic degradation with random jumps in multidimensional cases. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 483–492, 2015     

Fitting Lanchester equations to the battles of Kursk and Ardennes

Lanchester equations and their extensions are widely used to calculate attrition in models of warfare. This paper examines how Lanchester models fit detailed daily data on the battles of Kursk and Ardennes. The data on Kursk, often called the greatest tank battle in history, was only recently made available. A new approach is used to find the optimal parameter values and gain an understanding of how well various parameter combinations explain the battles. It turns out that a variety of Lanchester models fit the data about as well. This explains why previous studies on Ardennes, using different minimization techniques and data formulations, have found disparate optimal fits. We also find that none of the basic Lanchester laws (i.e., square, linear, and logarithmic) fit the data particularly well or consistently perform better than the others. This means that it does not matter which of these laws you use, for with the right coefficients you will get about the same result. Furthermore, no constant attrition coefficient Lanchester law fits very well. The failure to find a good‐fitting Lanchester model suggests that it may be beneficial to look for new ways to model highly aggregated attrition. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

The campaign of the lost footsteps: the pacification of Burma, 1885-95

ABSTRACT

What Rudyard Kipling called the ‘campaign of lost footsteps’ was the longest campaign fought by the Victorian army. The conquest of Upper Burma, an area of 140,000 sq. miles with a population of four million, took only three weeks in November 1885 and was accomplished with minimum cost. However, the removal and deportation of the Burmese King and dismantling of all traditional authority dismantled led to growing resistance to British rule leading to an increasingly difficult guerrilla war. Though the Burmese guerrillas were characterised by the British as mere bandits or dacoits, many were former soldiers along with Buddhist monks. The extremely difficult nature of campaigning in the terrain and climate of Burma was not sufficiently appreciated by the War Office, who viewed the conflict as a ‘subaltern’s war’ and ‘police’ work. Intended regime change was also not accompanied by any consideration of the likely implications. Prolonged insurgency necessitated deploying a force far larger than originally intended; though order was finally secured by 1895, the campaign proved destructive of Burmese society while British recruitment of hill tribes into the police and armed forces sowed the seeds for future divisions.     

United States defence contractors and the future of military operations

ABSTRACT

The United States’ global strategic outlook has shifted markedly since the end of major combat operations in Iraq and Afghanistan. As the United States’ strategic posture shifts, the nature of military operations is simultaneously changing rapidly. Many analysts predict that cyber-operations, autonomous weapons systems, artificial intelligence, and clandestine special forces operations will be central features in future conflicts. Although often overlooked by scholars and policy analysts, defence contractors are integral to the development and implementation of these emerging categories of warfare. This inquiry examines the evolving nature of the American defence industry and the roles corporations play in current theatres of conflict. Surprisingly, rather than becoming less reliant on defence contractors after their much-maligned performance in the wars in Iraq and Afghanistan, American military and intelligence agencies have become more dependent on the private sector as technology becomes increasingly central to warfare.