Using multiple searchers in constrained-path,moving-target search problems

The search theory open literature has paid little, if any, attention to the multiple-searcher, moving-target search problem. We develop an optimal branch-and-bound procedure and six heuristics for solving constrained-path problems with multiple searchers. Our optimal procedure outperforms existing approaches when used with only a single searcher. For more than one searcher, the time needed to guarantee an optimal solution is prohibitive. Our heuristics represent a wide variety of approaches: One solves partial problems optimally, two use paths based on maximizing the expected number of detections, two are genetic algorithm implementations, and one is local search with random restarts. A heuristic based on the expected number of detections obtains solutions within 2% of the best known for each one-, two-, and three-searcher test problem considered. For one- and two-searcher problems, the same heuristic's solution time is less than that of other heuristics. For three-searcher problems, a genetic algorithm implementation obtains the best-known solution in as little as 20% of other heuristic solution times. © 1996 John Wiley & Sons, Inc.     

The disconnect between arms control and DDR in peace processes

The article discusses the disconnect between arms control and disarmament practices vis-à-vis peacebuilding practices. It critically analyzes Disarmament, Demobilization, and Reintegration (DDR) practices focusing on their absence of dialogue with international arms control and disarmament (ACD) practices. It proposes that a conversation between experts involved in these distinct practices could promote a political discussion on the place of weapons held by state and non-state actors in times of peace. The argument is illustrated through an analysis of the treatment of rules on weapons in the Colombian peace process (2012–present) with the Revolutionary Armed Forces of Colombia (FARC). The article concludes that the disconnect between the arms control and disarmament and the peacebuilding associations, as seen in the context of DDR practices, reinstates the rule on the monopoly of violence by the state, preventing a broader discussion of the role of weapons and violence in the building of political communities.     

THE BRAZILIAN WAY

This article examines the positions held by Brazil under the administration of Luiz Inácio Lula da Silva (2003–present) on nuclear nonproliferation, arms control, and disarmament regimes and on contentious issues in those areas. Under Lula's government, Brazil has wanted to mediate between nuclear weapon and non-nuclear weapon states to consolidate its position as a strong negotiator and to benefit from the possible gains of this position in terms of greater participation in international institutions. It has also wanted to pressure nuclear weapon states to fulfill their disarmament obligations in order to reduce asymmetries in its relations with powerful nuclear weapon countries. At the same time, Brazil has tried to preserve its autonomy and flexibility to protect commercial secrets and preserve national security in relation to its own nuclear program.