Class scheduling algorithms for Navy training schools

The problem of developing good schedules for Navy C-Schools has been modeled as a combinatorial optimization problem. The only complicating feature of the problem is that classes must be grouped together into sequences known as pipelines. An ideal schedule will have all classes in a pipeline scheduled in consecutive weeks. The objective is to eliminate the nonproductive time spent by sailors at C-Schools who are waiting for the next class in a pipeline. In this investigation an implicit enumeration procedure for this problem was developed. The key component of our algorithm is a specialized greedy algorithm which is used to obtain a good initial incumbent. Often this initial incumbent is either an optimal schedule or a near optimal schedule. In an empirical analysis with the only other competing software system, our greedy heuristic found equivalent or better solutions in substantially less computer time. This greedy heuristic was extended and modified for the A-School scheduling problem and was found to be superior to its only competitor. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 533–551, 1998     

On the inspection game

The Inspection Game is a multistage game between a customs inspector and a smuggler, first studied by Melvin Dresher and Michael Maschler in the 1960s. An extension allowing the smuggler to act more than once, treated by Sakaguchi in a special case, is solved. Also, a more natural version of Sakaguchi's problem is solved in the special case where the smuggler may act at each stage. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 327–334, 1998     

The theory of combined-arms lanchester-type models of warfare

The mathematical theory necessary to solve combined arms models of military combat is presented here. We show how to apply the theory of positive operators to such models. Most of the results are purely qualitative in character showing that many properties of such systems are independent of the actual numerical values of the coefficients. Finally, we discuss in some detail an example of such a system.     

Use of completely reduced matrices in solving transportation problems with fixed charges

This paper shows how completely reduced matrices can be used in obtaining exact or approximate solutions to transportation problems with fixed charges. It does not treat methods for obtaining reduced matrices, which are available elsewhere, but it does discuss the problem of obtaining a completely reduced matrix, and then a general parametric solution to the primal problem, from any particular solution. Methods for obtaining particular solutions with determinacies of maximum order (solutions for the constant fixed charges problem) are then presented. The paper terminates with a discussion of methods which are useful in obtaining approximations to solutions of fixed charges problems with charges not constant.     

State and society in Asia

India and China are the 2 most populous countries of the world; in the 1950s, both countries initiated a centrally planned program for rapid development within vastly differing political systems. China embarked India's policy encouraged only voluntary acceptance of family planning. In both cases, however, government involvement in population forms a part of comprehensive national planning. Both countries rely on a limited resource base and technological sophistication in order to alleviate mass poverty and misery. The political implications of population growth cannot be neatly isolated from those that are generated by social and economic forces of change in a society that is in a transitional stage of modernization and development. Development has not been an unmixed bleesing; population growth is one of its counterproductive outcomes. The development process has begun to draw increasing attention to hitherto neglected correlates of fertility decline, such as a reduction in infant mortality, universal education, improvement in women's status, and women's participation in economic activity outside the home, all of which eventually result in greater demand for family planning services. Both the Indian and Chinese models highlight the importance of taking the people into one's confidence; the response of the common people to official initiatives is critical in securing a reduction in fertility levels. China has adopted a 1 child family policy, yet it is unreasonable to expect that the Indian people would agree to a nationally prescribed family size norm below 2 children. The principal determinant of future population trends in both these countries is the course of their politics. The success of developing countries will be assured if the developed nations support their progress without being worried about their population growth, which is the result of their unavoidable failure to modernize their social and economic structures.     

How to Fight Terrorism: Alternatives to Deterrence

Deterrence has been a crucial element in fighting terrorism, both in actual politics and rational choice analyses of terrorism. But there are superior strategies to deterrence. One is to make terrorist attacks less attractive. Another to raise the opportunity cost - rather than the material cost - to terrorists. These alternative strategies effectively dissuade potential terrorists. The strategies suggested here build on the "benevolence" system and tend to produce a positive sum game among the interacting parties. In contrast, the deterrence system is based on "threats" and tends to produce a negative sum game interaction.     

Preventive maintenance and replacement under additive damage

A system deteriorates due to shocks received at random times, each shock causing a random amount of damage which accumulates over time and may result in a system failure. Replacement of a failed system is mandatory, while an operable one may also be replaced. In addition, the shock process causing system deterioration may be controlled by continuous preventive maintenance expenditures. The joint problem of optimal maintenance and replacement is analyzed and it is shown that, under reasonable conditions, optimal maintenance rate is decreasing in the cumulative damage level and that beyond a certain critical level the system should be replaced. Meaningful bounds are established on the optimal policies and an illustrative example is provided.     

Book Reviews

The purpose of this article is to analyse British strategic nuclear targeting between 1974 and 1979, prior to the successful completion of the sophisticated modification to Polaris submarine-missile system codenamed Chevaline. It will use as its starting point the parameters for UK strategic nuclear targeting, and the foundation of the ‘Moscow Criterion’, prior to the deployment of Britain's Polaris submarines which began in 1968. It will then discuss the recommendation by the Chiefs of Staff to retarget Polaris in 1975/76 and the implications of that recommendation in terms of the British approach to strategic nuclear deterrence. The article will conclude with an assessment of these retargeting decisions on the decision to replace Polaris with the US Trident system in 1980.