A model for step‐stress accelerated life testing

Modern technology is producing high reliability products. Life testing for such products under normal use condition takes a lot of time to obtain a reasonable number of failures. In this situation a step‐stress procedure is preferred for accelerated life testing. In this paper we assume a Weibull and Lognormal model whose scale parameter depends upon the present level as well as the age at the entry in the present stress level. On the basis of that we propose a parametric model to the life distribution for step‐stress testing and suggest a suitable design to estimate the parameters involved in the model. A simulation study has been done by the proposed model based on maximum likelihood estimation. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2003     

Book reviews

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The US Military/NGO Relationship in Humanitarian Interventions by Chris Seiple, Peacekeeping Institute, Center for Strategic Leadership, US Army War College, 1996.

Uncivil Wars: International Security and the New Internal Conflicts by Donald M. Snow, London: Lynne Rienner Publishers, 1996, ISBN 1-55587-655-2 (pbk), £15.50, ISBN 1-55587-648-X (hbk), £33.50.

Intelligence Power in Peace and War by Michael Herman, Royal Institute for International Affairs, Cambridge: Cambridge University Press, 1996, ISBN 0-521-56231-7 (hbk), £50, ISBN 0-521-56636 (pbk), £16.95.

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Conversion Survey 1997: Global Disarmament and Disposal of Surplus Weapons by Bonn International Center for Conversion, Oxford: Oxford University Press, 1997.

Plutonium and Highly Enriched Uranium 1996: World Inventories, Capabilities and Policies by David Albright, Frans Berkhout and William Walker, Oxford: SIPRI and Oxford University Press, 1997.

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Exact first and second order moments of order statistics from the truncated exponential distribution

Exact expressions for the first and second order moments of order statistics from the truncated exponential distribution, when the proportion 1–P of truncation is known in advance, are presented in this paper. Tables of expected values and variances-covariances are given for P = 0.5 (0.1) 0.9 and n = 1 (1) 10.