An experimental comparison of solution algorithms for the single-machine tardiness problem

A basic problem in scheduling involves the sequencing of a set of independent tasks at a single facility with the objective of minimizing mean tardiness. Although the problem is relatively simple, the determination of an optimal sequence remains a challenging combinatorial problem. A number of algorithms have been developed for finding solutions, and this paper reports a comparative evaluation of these procedures. Computer programs for five separate algorithms were written and all were run on a data base designed to highlight computational differences. Optimizing algorithms developed by Emmons and by Srinivasan appeared to be particularly efficient in the comparative study.     

System comparison procedures for automatic target recognition systems

Estimating the performance of an automatic target recognition (ATR) system in terms of its probability of successfully identifying a target involves extensive image collection and processing, which can be very time‐consuming and expensive. Therefore, we investigate the Wald sequential test for the difference in two proportions as a sample size‐reducing alternative to ranking and selection procedures and confidence intervals. An analysis of the test parameters leads to a practical methodology for implementing the Wald test for fairly comparing two systems, based on specific experimental goals. The test is also extended with the modified, sequentially rejective Bonferroni procedure for the multiple pairwise comparison of more than two systems. Two sampling schemes for different experimental goals are also discussed. The test methodology is applied to actual data to compare different configurations of a specific ATR system, with the results demonstrating that the modified Wald sequential procedure is a useful alternative to comparing proportions with confidence intervals, particularly when data are expensive. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 357–371, 1999     

Heuristic procedures for scheduling job families with setups and due dates

This paper examines heuristic solution procedures for scheduling jobs on a single machine to minimize the maximum lateness in the presence of setup times between different job families. It reviews the state of knowledge about the solution of this problem, which is known to be difficult to solve in general, and examines natural solution approaches derived from some of the underlying theory. The emphasis is on the design and computational evaluation of new heuristic procedures. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 978–991, 1999     

Allocation of resources to offensive strategic weapon systems

In this paper a very versatile game model is developed for use in the long range planning of our strategic force posture. This highly aggregate model yields optimal force mixes for the triad (land- and sea-based missile systems and bombers) under a variety of constraints. The model described here is a survivability model; however, it is shown how the model can still be used as a measure of overall system effectiveness. Constraints imposed on the problem include both SALT and budget limitations.     

Equalities in transportation problems and characterizations of optimal solutions

This paper considers the classical finite linear transportation Problem (I) and two relaxations, (II) and (III), of it based on papers by Kantorovich and Rubinstein, and Kretschmer. Pseudo-metric type conditions on the cost matrix are given under which Problems (I) and (II) have common optimal value, and a proper subset of these conditions is sufficient for Problems (II) and (III) to have common optimal value. The relationships between the three problems provide a proof of Kantorovich's original characterization of optimal solutions to the standard transportation problem having as many origins as destinations. The result are extended to problems having cost matrices which are nonnegative row-column equivalent.     

A differential equation model of search for randomly arriving and departing targets

In this paper we analyze optimal search strategies in an environment in which multiple, independent targets arrive and depart at random. The analysis revolves around a continuous time differential equation model which captures the time dependent nature of the search process. We explore the impact on optimal strategies of nonzero travel times between regions as well as differing target arrival rates. We derive simple closed form expressions for determining if only one region should be searched.     

Indications and warning in Belgium: Brussels is not Delphi

The terrorist attacks in France and Belgium of 2015–2016 that occurred while these countries were in a heightened state of alert raise questions about indications and warning methodology as well as effectiveness of the blanket-protection deployment of security services assisted even by the military. Response and perhaps even more anticipation may require strategic rethinking in light of the predatory attacks that target the most vulnerable spots of the public space. This study looks at threat analysis in Belgium as conducted through her intelligence fusion centre Coordination Unit for Threat Analysis (CUTA)?????? since its inception in 2006. With a special focus on what is known, at the time of writing, about the terrorist attacks in Paris and Brussels, this study hopes to put into context how the system (mal)functions and will also consider the preventive measures that respond to the threat, and the international aspects which have implications far beyond Belgian borders. Therefore, a case is made for not just a Belgian homeland security framework, but one that fits into an EU-wide security concept.     

SECURITY AND FORCED MIGRATION CONCERNS IN SOUTH AFRICA

“As we close this century, there is for the first time realistic hope of a more just future. A Century stained with the sufferings of ceaseless war and atrocity is as much marked by our incomplete efforts to secure the foundations of an international society, one in which all peoples are equal and equally protected from abuse. The last decade has seen the application of dormant humanitarian principles and laws in various fora. The ICC offers us the opportunity to build on these disjointed enforcement efforts. A properly functioning permanent court will be humanity's best chance yet to move out of its self-destructive cycle. Justice is a vindication, a historical right and a deterrent.”     

The BWC protocol mandate for failure

The stage may be set for what could be a historic turning point in America's reliance on nuclear weapons to meet its fundamental national security interests. Proponents of a refurbished nuclear stockpile and infrastructure are convinced that nuclear weapons will remain central to U.S. security interests, yet they admit that there is no national consensus on the need for and role of nuclear weapons. Nuclear opponents are gravely concerned that to the extent nuclear refurbishment creates a global perception that nuclear weapons remain essential instruments, it will eviscerate nuclear nonproliferation measures precisely at a time when nuclear ambitions are growing. Moreover, opponents see deterrence through advanced conventional weapons as decisively more credible than any nuclear alternative. With hopes of elevating discourse to the national level, this article examines the key current arguments pro and con within the specialist community and forecasts changes in the U.S. nuclear arsenal over the next decade. It concludes with a brief prognosis on prospects for complete nuclear disarmament.