Lanchester for cyber: The mixed epidemic‐combat model

Future conflict between armed forces will occur both in the physical domain as well as the information domain. The linkage of these domains is not yet fully understood. We study the dynamics of a force subject to kinetic effects as well as a specific network effect–spreading malware. In the course of our study, we unify two well‐studied models: the Lanchester model of armed conflict and deterministic models of epidemiology. We develop basic results, including a rule for determining when explicit modeling of network propagation is required. We then generalize the model to a force subdivided by both physical and network topology, and demonstrate the specific case where the force is divided between front‐ and rear‐echelons. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Urban gangs evolving as criminal Netwar actors

The nature of conflict and crime is changing. Technology allows groups to spread their influence without regard to geographic limitations. A shift from hierarchies to network organizational forms is also occurring. As a consequence non‐state actors can extend their influence to gain social, political or economic power and challenge state institutions. This article examines the potential for gangs, transnational criminals and terrorists to embrace network forms and utilize technology to wage netwar. Factors which influence ‘third generation’ gang organization (politicization, internationalization and sophistication) are described to illustrate how a net‐based threat can mature. A move toward network organization within transnational criminal organizations and terrorist groups demonstrating the potential for these classic criminal entities to emerge as netwar actors is also reviewed. Finally, the need for state institutions such as the police and military to develop networked responses to combat networked threats is stated.     

Cutting,Running, or Otherwise? The US Decision to withdraw from Somalia

Although President Bill Clinton made the decision to withdraw U.S. combat troops from Somalia within three days of the disastrous Mogadishu raid that resulted in the deaths of 18 U.S. servicemen, casualties were not the only consideration. Many other factors were at play. Waning Congressional and public enthusiasm for a new “nation-building” mandate, the strategic insignificance of Somalia in the post-Cold War era, and a host of other foreign policy issues had been eroding U.S. support for the mission in Somalia for months. The “Black Hawk Down” incident merely accelerated the final rupture in public and Congressional support, forcing the president to bring the troops home. It was not a simple case of casualty aversion.     

‘Like going to a fiesta’ – the role of female fighters in Colombia's FARC-EP

Traditionally women and children have been seen as victims rather than protagonists in conflict. However, since the 1970s, women and children have assumed an active role as combatants in Colombian insurgencies. This is especially true of the FARC-EP, which integrates women into its political and military structure in ways that give them a sense of participation, accomplishment and satisfaction. Without their contributions, including sexual services, the FARC could probably not survive. However, despite their favourable experiences, many women ultimately become disillusioned with the FARC's masculine culture and value system that fails to accommodate their aspirations as women.     

Quadratic bottleneck problems

We study the quadratic bottleneck problem (QBP) which generalizes several well‐studied optimization problems. A weak duality theorem is introduced along with a general purpose algorithm to solve QBP. An example is given which illustrates duality gap in the weak duality theorem. It is shown that the special case of QBP where feasible solutions are subsets of a finite set having the same cardinality is NP‐hard. Likewise the quadratic bottleneck spanning tree problem (QBST) is shown to be NP‐hard on a bipartite graph even if the cost function takes 0–1 values only. Two lower bounds for QBST are derived and compared. Efficient heuristic algorithms are presented for QBST along with computational results. When the cost function is decomposable, we show that QBP is solvable in polynomial time whenever an associated linear bottleneck problem can be solved in polynomial time. As a consequence, QBP with feasible solutions form spanning trees, s‐t paths, matchings, etc., of a graph are solvable in polynomial time with a decomposable cost function. We also show that QBP can be formulated as a quadratic minsum problem and establish some asymptotic results. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

On the bivariate negative binomial distribution of mitchell and paulson

The bivariate negative binomial distribution of Mitchell and Paulson [17] for the case b = c = 0 is shown to be equivalent to the accident proneness model of Edwards and Gurland [4] and Subrahmaniam [19,20]. The diagonal series expansion of its joint probability function is then derived. Two other formulations of this distribution are also considered: (i) as a mixture model, which showed how it arises as the discrete analogue to the Wicksell-Kibble bivariate gamma distribution, and (ii) as a consequence of the linear birth-and-death process with immigration.