Power series expansions for the distribution and mean value function of a geometric process with Weibull interarrival times

The geometric process is considered when the distribution of the first interarrival time is assumed to be Weibull. Its one‐dimensional probability distribution is derived as a power series expansion of the convolution of the Weibull distributions. Further, the mean value function is expanded into a power series using an integral equation. © 2014 Wiley Periodicals, Inc. Naval Research Logistics, 61: 599–603, 2014     

VISIONS OF FISSION

For many years, non-nuclear weapons states have sought binding commitments from nuclear armed states that they would not be the victim of either the threat or use of nuclear weapons—so-called negative security assurances (NSAs). The nuclear weapon states have traditionally resisted granting such unconditional NSAs. Recent U.S. efforts to use nuclear deterrence against the acquisition and use by other states of chemical, biological and radiological weapons, however, have further exacerbated this divide. This article analyzes the historical development of NSAs and contrasts U.S. commitments not to use nuclear weapons with the empirical realities of current U.S. nuclear weapons employment doctrines. The authors conclude that NSAs are most likely to be issued as unilateral declarations and that such pledges are the worst possible manner in which to handle the issue of security assurance.     

UNDER THE RADAR?

Missile Contagion: Cruise Missile Proliferation and the Threat to International Security, by Dennis M. Gormley. Praeger Security International, 2008. 272 pages, $54.95.     

MAKING THE AGENDA STICK Lessons Learned From the 2007 NPT PrepCom

After the conclusion of the 2008 Preparatory Committee (PrepCom) for the 2010 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), the Nonproliferation Review interviewed Ambassador Yukiya Amano of Japan, who presided over the 2007 session of the PrepCom in Vienna. He provided valuable insights into his preparations for the PrepCom and shared his thoughts on some of the most pressing issues that confronted his chairmanship and the PrepCom as a whole. The interview also provides useful perspectives on the future of the strengthened review process.     

陆军作战仿真模型标准化研究

模型标准化是规范仿真模型开发,避免低水平重复建设的重要环节。在对陆军作战仿真模型体系进行分析和归纳的基础上,对仿真模型架构、模型构建、模型管理以及模型交互进行了标准化设计,提出了基于插件机制的“柔性”仿真模型架构、仿真实体组件化建模机制、采用“方案－单元－实体－组件”方式的仿真实体管理机制以及采用消息驱动、事件订购和分发方式的模型交互机制。     

An integral equation for the second moment function of a geometric process and its numerical solution

In this article, an integral equation satisfied by the second moment function M₂(t) of a geometric process is obtained. The numerical method based on the trapezoidal integration rule proposed by Tang and Lam for the geometric function M(t) is adapted to solve this integral equation. To illustrate the numerical method, the first interarrival time is assumed to be one of four common lifetime distributions, namely, exponential, gamma, Weibull, and lognormal. In addition to this method, a power series expansion is derived using the integral equation for the second moment function M₂(t), when the first interarrival time has an exponential distribution.     

SYMBIOTIC SPIES

Spying on the Nuclear Bear: Anglo-American Intelligence and the Soviet Bomb, by Michael S. Goodman. Stanford University Press, 2007. 295 pages, $50.