The Changing Pakistan Army Officer Corps

The Pakistan Army elicits many concerns about terrorism, nuclear and the coherence of the state. However, very little is actually known about this institution. This article mobilizes unique data to address one important facet: the Army's geographical recruitment base. We find that the Pakistan Army has been successful at expanding the geographical recruitment base while some groups (namely those who are native to Sindh) remain highly under-represented. We also find that the officer corps is increasingly coming from urban areas. We conclude with a discussion of the implications of these important shifts subject to the limitations of our data.     

Institutional Analysis and Irregular Warfare: A Case Study of the French Army in Algeria 1954–1960

This article proposes a case study to illustrate the usefulness of sociological institutional analysis as a method to uncover ‘blue force’ challenges to deal with irregular warfare. The French Army's adaptation to revolutionary warfare in Algeria, starting in 1954, is used to illustrate both the application of the methodology and how institutional forces can hinder as well as overwhelm transformation for irregular warfare. The analysis emphasizes three key dimensions of the French Army's institutional adaptation: the regulative, normative and cognitive. These empirical elements are used to show how they interacted and influenced the institutional implementation of the French COIN structures.     

Insights from a Database of Lashkar-e-Taiba and Hizb-ul-Mujahideen Militants

This article uses a novel database of 1,625 posthumously published biographies of members of two Islamist militant organizations (Lashkar-e-Taiba (LeT) and Hizb-ul-Mujahideen (HM)), all of whom were killed in the course of carrying out militant attacks. In general, each biography provides data on the militant’s birthplace, education, recruitment, and training. The number of observations in this database is a full order of magnitude larger than those of previous databases assembled from militant biographies. While the sample of militants in this database is the product of multiple selection effects, analysis of the database undermines many common myths about Pakistani militants and casts doubt on current policy approaches to mitigating Islamist militancy in Pakistan.     

Supporting allies in counterinsurgency: Britain and the Dhofar Rebellion

From 1964 to 1975 a small group of British officers, advisors, and trainers guided the forces of the Sultanate of Oman to victory in their conflict with the Marxist insurgents of the People's Front for the Liberation of the Occupied Arabian Gulf (PFLOAG). This campaign provides a clear example of how to effectively support an ally's counterinsurgency efforts with a minimal commitment of men and material. In particular, the critical assistance provided by the British consisted of experienced leadership and skilled technical support personnel as well as a viable strategy for victory. However, more important for the ultimate success of the counterinsurgency campaign was the emergence of new progressive leadership with the accession of Sultan Qaboos. The most important lesson from this study is that while security assistance can reinforce positive political efforts, it is not enough on its own to bring about a victory in an unfavourable political environment.     

Analysis of algorithms for two‐stage flowshops with multi‐processor task flexibility

In this article we introduce a 2‐machine flowshop with processing flexibility. Two processing modes are available for each task: namely, processing by the designated processor, and processing simultaneously by both processors. The objective studied is makespan minimization. This production environment is encountered in repetitive manufacturing shops equipped with processors that have the flexibility to execute orders either individually or in coordination. In the latter case, the product designer exploits processing synergies between two processors so as to execute a particular task much faster than a dedicated processor. This type of flowshop environment is also encountered in labor‐intensive assembly lines where products moving downstream can be processed either in the designated assembly stations or by pulling together the work teams of adjacent stations. This scheduling problem requires determining the mode of operation of each task, and the subsequent scheduling that preserves the flowshop constraints. We show that the problem is ordinary NP‐complete and obtain an optimal solution using a dynamic programming algorithm with considerable computational requirements for medium and large problems. Then, we present a number of dynamic programming relaxations and analyze their worst‐case error performance. Finally, we present a polynomial time heuristic with worst‐case error performance comparable to that of the dynamic programming relaxations. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

An FPTAS for scheduling a two‐machine flowshop with one unavailability interval

We study a deterministic two‐machine flowshop scheduling problem with an assumption that one of the two machines is not available in a specified time period. This period can be due to a breakdown, preventive maintenance, or processing unfinished jobs from a previous planning horizon. The problem is known to be NP‐hard. Pseudopolynomial dynamic programming algorithms and heuristics with worst case error bounds are given in the literature to solve the problem. They are different for the cases when the unavailability interval is for the first or second machine. The existence of a fully polynomial time approximation scheme (FPTAS) was formulated as an open conjecture in the literature. In this paper, we show that the two cases of the problem under study are equivalent to similar partition type problems. Then we derive a generic FPTAS for the latter problems with O(n⁵/ε⁴) time complexity. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

Single machine scheduling with a restricted rate‐modifying activity

In this paper we consider the problem of scheduling a set of jobs on a single machine on which a rate‐modifying activity may be performed. The rate‐modifying activity is an activity that changes the production rate of the machine. So the processing time of a job is a variable, which depends on whether it is scheduled before or after the rate‐modifying activity. We assume that the rate‐modifying activity can take place only at certain predetermined time points, which is a constrained case of a similar problem discussed in the literature. The decisions under consideration are whether and when to schedule the rate‐modifying activity, and how to sequence the jobs in order to minimize some objectives. We study the problems of minimizing makespan and total completion time. We first analyze the computational complexity of both problems for most of the possible versions. The analysis shows that the problems are NP‐hard even for some special cases. Furthermore, for the NP‐hard cases of the makespan problem, we present a pseudo‐polynomial time optimal algorithm and a fully polynomial time approximation scheme. For the total completion time problem, we provide a pseudo‐polynomial time optimal algorithm for the case with agreeable modifying rates. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005     

Modeling the operation of multireservoir systems using decomposition and stochastic dynamic programming

Stochastic dynamic programming models are attractive for multireservoir control problems because they allow non‐linear features to be incorporated and changes in hydrological conditions to be modeled as Markov processes. However, with the exception of the simplest cases, these models are computationally intractable because of the high dimension of the state and action spaces involved. This paper proposes a new method of determining an operating policy for a multireservoir control problem that uses stochastic dynamic programming, but is practical for systems with many reservoirs. Decomposition is first used to reduce the problem to a number of independent subproblems. Each subproblem is formulated as a low‐dimensional stochastic dynamic program and solved to determine the operating policy for one of the reservoirs in the system. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006