Estimating component characteristics from system failure‐time data

Suppose that failure times are available from a random sample of N systems of a given, fixed design with components which have i.i.d. lifetimes distributed according to a common distribution F. The inverse problem of estimating F from data on observed system lifetimes is considered. Using the known relationship between the system and component lifetime distributions via signature and domination theory, the nonparametric maximum likelihood estimator _N(t) of the component survival function (t) is identified and shown to be accessible numerically in any application of interest. The asymptotic distribution of _N(t) is also identified, facilitating the construction of approximate confidence intervals for (t) for N sufficiently large. Simulation results for samples of size N = 50 and N = 100 for a collection of five parametric lifetime models demonstrate the utility of the recommended estimator. Possible extensions beyond the i.i.d. framework are discussed in the concluding section. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

The ‘first’ surge: the repulse of the Easter Invasion in South Vietnam, 1972 – implications for Iraq and Afghanistan

In a military intervention, do surges work? I compare the failed ‘surge’ in Vietnam, the repulse of the Easter Invasion in 1972, as a means of assessing the more ambiguous surges in Iraq and Afghanistan. I identify four features of a surge for this analysis: the military dimensions and strategy of the surging forces, the military capabilities of the host forces, the political vitality and will of the host country, and the political commitment in the domestic politics of the intervener. I find that the last feature is the most critical; and, in all three surges, the American political commitment was lacking.     

Integrating the Services and Harnessing the Military Area Commands

ABSTRACT

The Chinese People’s Liberation Army (PLA) is halfway through a multi-decade modernization process. It has begun a major restructuring effort as it shifts its focus from a traditional continental defensive posture to a more maritime-oriented emphasis. In order to create more balanced joint force, it has adjusted the structure of its highest command organization, the Central Military Commission; abolished the former four General Departments and seven Military Regions; created five new joint Theater Commands and service-level commands for the Army and Rocket Force; and is reducing the size of its active duty force by 300,000 personnel. While seeking to overcome numerous internal obstacles, the PLA continues to develop and improve its capabilities to conduct integrated joint operations to deter a variety of threats to China’s sovereignty and territory and, if deterrence fails, to win informationized local war.