Resume of James Daniel Esary, 1973

Naval Postgraduate School Faculty Resum

Resume of James Daniel Esary, 1970

Naval Postgraduate School Faculty Resum

Review of interactions between the Naval Postgraduate School and the Naval Undersea Warfare Engineering Station, 1973-1986

http://archive.org/details/reviewofinteract00wilsDept. of Physics.N

Studies on damage aggregation for weapons salvos

This document records three working studies from an ongoing investigation of models and methods for the prediction of the cumulative effect of weapons salvos. The first paper is about an extant formula for estimating the expected proportion of damage to an area target, which proves to be optimistic when compared to a plausible model for the effect of the salvo. The second paper describes an alternate formula which is conservative when compared to the same model. The third paper describes a basic case of an emerging family of target configuration and weapons impact scenarios which lead to the plausible modelPrepared for Naval Weapons Center, China Lake, CA, and funded by the Naval Postgraduate School.http://archive.org/details/studiesondamagea00esarO&MN, Direct FundineNAApproved for public release; distribution is unlimited

Multivariate geometric distributions generated by a cumulative damage process

Two (narrow and wide) multivariate geometric analogues of the Marshall-Olkin multivariate exponetial distribution are derived from the following cumulative damage model. A set of devices is exposed to a common damage process. Damage occurs in discrete cycles. On each cycle the amount of damage is an independent observation on a nonnegative random variable. Damages accumulate additively. Each device has its own random breaking threshold. A device fails when the accumulated damage exceeds its threshold. Thresholds are independent of damages, and have a Marshall-Olkin multivariate exponential distribution. The joint distribution of the random numbers of cycles up to and including failure of the devices has the wide multivariate geometric distribution. It has the narrow multivariate geometric distribution if the damage variable is infinitely divisible. (Author)http://archive.org/details/multivariategeom00esarN

Families of components, and systems, exposed to a compound poisson damage process

A fairly common failure model in a wide variety of contexts is a cumulative damage process, in which shocks occur randomly in time and associated with each shock there is a random amount of damage which adds to previously incurred damage until a breaking threshold is reached. The multivariate life distributions that are induced when several "components," each with its own breaking threshold, are exposed to the same cumulative damage process are of interest in their own right, and are important examples in the general study of multivariate life distributions. This paper is a summary of some results about the very special, but central, case in which the cumulative damage process is a compound Poisson process. It is focused on the multivariate life distributions that arise when the component breaking thresholds are random and have a Marshall-Olkin multivariate exponential distribution. There are two relevant multivariate life distributions that can be derived, an intermediate distribution for the number of shocks (cycles) to failure and the final distribution for the actual times to failure. The results have application to the life distribution of a coherent system whose components are exposed to the damage process. (Author)http://archive.org/details/familiesofcompon00esarN

Properties of an approximate hazard transform

The calculation of the exact reliability of complex systems is a difficult and tedious task. Consequently simple approximating techniques have great practical value. The hazard transform of a system is an invertible transformation of its reliability function which is convenient and useful in both applied and theoretical reliability work. A simple calculus for finding an approximate hazard transform for systems formed by series and parallel combinations of components is extended so that it can be used for any coherent system. The extended calculus is shown to lead to conservative approximations. A first order version of the extended calculus is also discussed. This method of approximation is even more simple to use, but is not always conservative. Examples of its application indicate that it is capable of giving quite accurate results. (Author)http://archive.org/details/propertiesofappr00esa

Studies on damage aggregation for weapons salvos II

This document records three working studies from an ongoing investigation of models and methods for the prediction of the cumulative effect of weapons salvos. It is the second such document, following NPS Technical Report NPS55-90-16, July 1990. Its first two papers are about cellular targeting scenarios which lead to the proportional damage aggregation mechanism which has figured strongly in the investigation so far. The other paper extends an earlier comparison of an empirical rule for damage aggregation to the results of models combining proportional damage aggregation with various weapons hit distributionsNaval Weapons Center, China Lake, CAhttp://archive.org/details/studiesondamageagg00esarO&MN, Direct FundingNAApproved for public release; distribution is unlimited