Estimating critical path and arc probabilities in stochastic activity networks

This article describes a new procedure for estimating parameters of a stochastic activity network of N arcs. The parameters include the probability that path m is the longest path, the probability that path m is the shortest path, the probability that arc i is on the longest path, and the probability that arc i is on the shortest path. The proposed procedure uses quasirandom points together with information on a cutset ? of the network to produce an upper bound of O[(log K)^N?|?|+1/K] on the absolute error of approximation, where K denotes the number of replications. This is a deterministic bound and is more favorable than the convergence rate of 1/K^1/2 that one obtains from the standard error for K independent replications using random sampling. It is also shown how series reduction can improve the convergence rate by reducing the exponent on log K. The technique is illustrated using a Monte Carlo sampling experiment for a network of 16 relevant arcs with a cutset of ? = 7 arcs. The illustration shows the superior performance of using quasirandom points with a cutset (plan A) and the even better performance of using quasirandom points with the cutset together with series reduction (plan B) with regard to mean square error. However, it also shows that computation time considerations favor plan A when K is small and plan B when K is large.     

Some branch-and-bound procedures for fixed-cost transportation problems

In this article we present three properties that will improve the performance of branch-and-bound algorithms for fixed-cost transportation problems. By applying Lagrangian relaxation we show that one can develop stronger up and down penalties than those traditionally used and also develop a strengthened penalty for nonbasic variables. We also show that it is possible to “look ahead” of a particular node and determine the solution at the next node without actually calculating it. We present computational evidence by comparing our developments with existing procedures.     

Minimizing the sum of absolute lateness in single-machine and multimachine scheduling

Kanet addressed the problem of scheduling n jobs on one machine so as to minimize the sum of absolute lateness under a restrictive assumption on their common due date. This article extends the results to the problem of scheduling n jobs on m parallel identical processors in order to minimize the sum of absolute lateness. Also, a heuristic algorithm for a more general version with no restriction on the common due date, for the problem of n-job single-machine scheduling is presented and its performance is reported.     

Rising Tide,Dispersing Waves: Opportunities and Challenges for Chinese Seapower Development

Abstract

This article surveys China’s current naval forces and considers key dynamics and possible Chinese naval futures to 2020, the projected end of Beijing’s ‘strategic window of opportunity’, the idea that a peaceful external environment for economic development, globalization, and integration of China into the global economy allows China to benefit from diversion of US attention to countering terrorism. It considers broad possibilities through 2030, the general limit of public US government projections, and by which time multiple factors will likely slow China’s growth and compete for leadership focus and resources.     

Planning accelerated life tests for censored two‐parameter exponential distributions

We consider optimal test plans involving life distributions with failure‐free life, i.e., where there is an unknown threshold parameter below which no failure will occur. These distributions do not satisfy the regularity conditions and thus the usual approach of using the Fisher information matrix to obtain an optimal accelerated life testing (ALT) plan cannot be applied. In this paper, we assume that lifetime follows a two‐parameter exponential distribution and the stress‐life relationship is given by the inverse power law model. Near‐optimal test plans for constant‐stress ALT under both failure‐censoring and time‐censoring are obtained. We first obtain unbiased estimates for the parameters and give the approximate variance of these estimates for both failure‐censored and time‐censored data. Using these results, the variance for the approximate unbiased estimate of a percentile at a design stress is computed and then minimized to produce the near‐optimal plan. Finally, a numerical example is presented together with simulation results to study the accuracy of the approximate variance given by the proposed plan and show that it outperforms the equal‐allocation plan. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 169–186, 1999     

British Armour and rearmament in the 1930s

This paper considers the contribution of military publishing to the nineteenth-century military revolution leading to the Great War. The subject is addressed in four contexts. The first is informational, analyzing the role of military publications in making available data and ideas that increased military effectiveness. The second is syncretic, evaluating the effect of military publications on cohesion within increasingly large, complex armies, and between armies and their societies. The third is internal. It discusses the contributions to professional insecurity generated by print, and by its electronic extensions the telegraph and the telephone. Finally, the paper considers the print revolution's influence on actual war-fighting     

France and the Gulf War of 1990–1991: Political‐military lessons learned

Kathleen Burk, Britain, America and the Sinews of War 1914–1918. Boston and London: Allen &; Unwin, 1985. Pp.x + 286; £20.00.

Keith Jeffery, The British Army and the Crisis of Empire 1918–1922. Manchester: Manchester University Press, 1984. Pp.viii + 200; £21.00.

Carlo D'Este, Decision in Normandy. London: Pan Books in association with Collins, 1984. Pp.xii + 555; £3.95.

R. J. Overy, Goering: The ‘Iron Man’, London: Routledge &; Kegan Paul, 1984. Pp. x + 310; bibliography; index; £14.95.

John Barron, KGB: The Hidden Hand. New York: Reader's Digest Press, 1983. Pp.489. $15.95.

Edward Van Der Rhoer, The Shadow Network: Espionage as an Instrument of Soviet Policy, New York: Charles Scribner's Sons, 1983. Pp.359. $19.95.

David Holloway and Jane M. O. Sharp (eds.), The Warsaw Pact: Alliance in Transition? London: Macmillan Press, 1984. Pp.290; £25.

A. Ross Johnson, Robert W. Dean and Alexander Alexiev, East European Military Establishments: The Warsaw Pact Northern Tier. New York: Crane, Russak, 1982. Pp.xiii + 182; $19.50.

Condoleezza Rice, The Soviet Union and the Czechoslovak Army, 1948–1983: Uncertain Allegiance. Princeton, NJ: Princeton University Press, 1985. Pp.xiv + 303; £40.40.

Trevor Taylor, European Defence Cooperation (Chatham House Papers, No. 24). London: Routledge &; Kegan Paul for RIIA, 1984. Pp.97; £4.95.

Phil Williams, US Troops in Europe (Chatham House Papers, No. 25). London: Routledge &; Kegan Paul for RIIA, 1984. Pp.87; £5.95.

Daniel Frei, Assumptions and Perceptions in Disarmament. New York and Geneva: United Nations, 1984. Pp.xiv + 321; NP.

Joseph Rotblat and Alessandro Pascolini (eds.), The Arms Race at a Time of Decision, Annals of Pugwash 1983. London and Basingstoke: Macmillan, 1984. Pp.xxiv + 291; £20 (hardback) and £7.95 (paperback).

Philip H. Frankel, Pretoria's Praetorians. Cambridge: Cambridge University Press, 1984. Pp. xx + 215; £23.50.

Brian May, Russia, America, the Bomb and the Fall of Western Europe. London: Routledge &; Kegan Paul, 1984. Pp.vii + 248. £11.95.

Robert Jervis, The Illogic of American Nuclear Strategy. Ithaca and London: Cornell University Press, 1984. Pp.203; $19.95.