An algorithm for maximizing target achievement in the stochastic knapsack problem with normal returns

We consider the stochastic linear knapsack problem in which costs are known with certainty but returns are independent, normally distributed random variables. The objective is to maximize the probability that the overall return equals or exceeds a specified target value. A previously proposed preference order dynamic programming-based algorithm has been shown to be potentially suboptimal. We offer an alternative hybrid DP/branch-and-bound algorithm that both guarantees optimality and significantly outperforms generating the set of Pareto optimal returns.© 1993 John Wiley & Sons, Inc.     

Sandwich approximation of univariate convex functions with an application to separable convex programming

In this article an algorithm for computing upper and lower ? approximations of a (implicitly or explicitly) given convex function h defined on an interval of length T is developed. The approximations can be obtained under weak assumptions on h (in particular, no differentiability), and the error decreases quadratically with the number of iterations. To reach an absolute accuracy of ? the number of iterations is bounded by

     

Fitting Lanchester equations to the battles of Kursk and Ardennes

Lanchester equations and their extensions are widely used to calculate attrition in models of warfare. This paper examines how Lanchester models fit detailed daily data on the battles of Kursk and Ardennes. The data on Kursk, often called the greatest tank battle in history, was only recently made available. A new approach is used to find the optimal parameter values and gain an understanding of how well various parameter combinations explain the battles. It turns out that a variety of Lanchester models fit the data about as well. This explains why previous studies on Ardennes, using different minimization techniques and data formulations, have found disparate optimal fits. We also find that none of the basic Lanchester laws (i.e., square, linear, and logarithmic) fit the data particularly well or consistently perform better than the others. This means that it does not matter which of these laws you use, for with the right coefficients you will get about the same result. Furthermore, no constant attrition coefficient Lanchester law fits very well. The failure to find a good‐fitting Lanchester model suggests that it may be beneficial to look for new ways to model highly aggregated attrition. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

Polynomial‐time approximation schemes for two‐machine open shop scheduling with nonavailability constraints

This paper addresses a two‐machine open shop scheduling problem, in which the machines are not continuously available for processing. The processing of an operation affected by a non‐availability interval can be interrupted and resumed later. The objective is to minimize the makespan. We present two polynomial‐time approximation schemes, one of which handles the problem with one non‐availability interval on each machine and the other for the problem with several non‐availability intervals on one of the machines. Problems with a more general structure of the non‐availability intervals are not approximable in polynomial time within a constant factor, unless . © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

The Wilson government and the demise of TSR‐2, October 1964 – April 1965

Domestic factors play an important role in the formulation and evolution of a country's foreign and security policy. This is clearly seen in the case study of a Soviet successor state, Ukraine. The article brings together in seven sections theory with the key domestic factors that influence Ukrainian security policy, such as economics, energy, national identity, elites and political parties. The article provides an insight into how these domestic factors influence the course of Ukrainian security policy which is striking a balance between the twin extremes of Soviet re‐integration, which would be tantamount to the loss of independence, and nationalist maximalism which seeks to place as much distance as possible between Ukraine and Russia.     

The Rebirth of Insurgency in Peru

Peru has battled two major insurgent movements since 1980. Around 25,000 Peruvians have died in this war between the government against the Shining Path and the MRTA. The Peruvian military has been incapable of achieving total victory after several major operations and the capture of just about every major rebel leader. Even worse, after a few years of almost no activity, Shining Path seems to be re-emerging. The last remaining members of this insurgent group have made alliances with foreign terrorist groups, used drug traffic to fund their fight and sweet talked people who are very disappointed and mad at the current Toledo administration, to gain more supporters. Major changes have to occur to prevent both groups from becoming threats to national security and society as a whole, taking the country back to times when around half of the nation was declared to be under terrorist control. The defense budget must be increased to open new bases, buy new equipment and train soldiers better to fight the insurgents more effectively. At the same time, major social changes need to occur; Toledo and his government must gain the trust and sympathy of Peruvians again by working for and with them.     

Book reviews

Norman Cigar, Genocide in Bosnia: The Policy of “Ethnic Cleansing”. College Station, Texas: Texas A&M University Press, 1995. Pp.xiv + 247; app., map, notes, cartoon.

Maria Jose Moyano, Argentina's Lost Patrol: Armed Struggle, 1969–1979. New Haven: Connecticut Yale University Press, 1995. Pp.xiii + 226, biblio., abbreviations, 10 figures, 1 map, tables, index; $25/£16.95. ISBN 0–300–01622–6.

Donald E. Schulz and Deborah Sundloff Schulz, The United States, Honduras, and the Crisis in Central America, Westview Thematic Studies in Latin America, Boulder, Co: Westview, 1994. Pp.368, map, figure, select biblio., abbreviations, index. $52.50/£37.50; (cloth) $17.95/£11.95 (paper). ISBN 0–8133–1324–4 and 1323–6.

Joseph H. Alexander and Merrill L. Bartlett, Sea Soldiers in the Cold War: Amphibious Warfare 1945–1991. Annapolis, Maryland: Naval Institute Press, 1995. Pp.iii + 178, 1 map, 29 illus, biblio, index. $32.95. ISBN

Gary P. Cox, The Halt in the Mud: French Strategic Planning from Waterloo to Sedan. Westview Press, 1994. Pp.258, maps, notes, biblio, index. £33.50. ISBN 0–133–1536–0.     

It's all the rage: why mechanization doesn't explain COIN outcomes

A recent article, ‘Rage Against the Machines’, does a disservice to the debate over what explains counterinsurgency (COIN) success. While it establishes a negative correlation between the diffusion of military mechanization in the state system and COIN success, its theoretical argument does not hold up under close scrutiny and its micro-case comparison of two units in Iraq during 2003–2004 ignores obvious counter-examples and factors that influence COIN success, such as leadership. A deeper inquiry would have revealed that there is much more to COIN success than simply not having access to vehicles.     

Whatever happened to South America's splendid little wars?

South America has gained international media attention due to its ongoing arms race, with politicians and analysts warning about the possibility of war. Nevertheless, since the Chaco War in the 1930s, the region has seldom faced major inter-state wars, all of which have been short-lived and with relatively few casualties. This article will discuss in greater detail the ongoing arms race in South America, portraying it as a race ‘of levels’, with not all countries carrying out massive weaponry purchases. Finally, I will discuss regional geopolitics, geosecurity and integration as part of an analysis regarding the unlikelihood of war.