The 22 September 1979 Vela Incident: The Detected Double-Flash

On 22 September 1979 two optical sensors on U.S. satellite Vela 6911 detected a double-flash of light that appeared characteristic of an atmospheric nuclear explosion conducted over the southern Atlantic or Indian Ocean. It became known as the Vela Incident, Event 747, or Alert 747. An anomaly between the amplitude of the two signals during the second pulse led a U.S. government expert panel established to assess the event to conclude in mid-1980 that a more likely explanation was the impact of a small meteoroid on the satellite, the debris from which reflected sunlight into the sensors' field of view. No model was presented to support the contention, and a similar anomaly—known as background modulation—was a given for the second pulse of all confirmed explosions detected by Vela, though beginning later. Nonetheless, this event has remained the subject of intense debate. This article reviews the evidence and presents an updated analysis of the original Vela signal based on recently declassified literature and on modern knowledge of interplanetary dust and hyper velocity impact. Given the geometry of the satellite, and that the bulk of the surface comprised solar panels, much of the debris from any collision would be carried away from the sensors' field of view. Thus, a meteoroid collision appears much less likely than previously assumed. The double flash is instead consistent with a nuclear explosion, albeit detected by an aged satellite for which background modulation was abnormal and/or commenced earlier, also seen in post-event SYSTEM tests. A companion paper to be published in 2018 presents radionuclide and hydroacoustic evidence supporting the conclusion that the Vela Incident was a nuclear weapon test explosion.     

Nuclear weapons and alliance institutions in the era of President Trump

The swearing in of Donald Trump as the 45th President of the United States presages, at the very least, a period of flux in American strategy with respect to the relationship between nuclear weapons and alliances. In this response to three thoughtful rejoinders to our article, “Nuclear weapons, the United States and alliances in Europe and Asia: Toward an institutional perspective,” we clarify key aspects of our argument and discuss why alliance institutions are likely to be relatively robust in the face of change, how they can influence national decision-making, and argue that they may exert a moderating influence over the new administration.     

边消警部队政工专业研究生教学探讨

武警学院边消警部队政治工作专业的研究生教学要抓好的问题是:选准苗子,严格把好研究生的入学关;做好教学的各项准备工作,严格把好教学关;注意各方协调,齐抓共管,把好对研究生的管理关;不断加强研究生教学的硬件建设,把好保障关;坚持各项政策标准和原则,把好研究生毕业质量关。     

Local search methods for the discrete time/resource trade-off problem in project networks

In this paper we consider the discrete time/resource trade-off problem in project networks. Given a project network consisting of nodes (activities) and arcs (technological precedence relations), in which the duration of the activities is a discrete, nonincreasing function of the amount of a single renewable resource committed to it, the discrete time/resource trade-off problem minimizes the project makespan subject to precedence constraints and a single renewable resource constraint. For each activity, a work content is specified such that all execution modes (duration/resource requirement pairs) for performing the activity are allowed as long as the product of the duration and the resource requirement is at least as large as the specified work content. We present a tabu search procedure which is based on a decomposition of the problem into a mode assignment phase and a resource-constrained project scheduling phase with fixed mode assignments. Extensive computational experience, including a comparison with other local search methods, is reported. © 1998 John Wiley & Sons, Inc. Naval Research Logistics 45: 553–578, 1998     

The knapsack problem: A survey

A unifying survey of the literature related to the knapsack problem; that is, maximize \documentclass{article}\pagestyle{empty}\begin{document}$ \sum\limits_i {v_i x_{i,} } $\end{document}, subject to \documentclass{article}\pagestyle{empty}\begin{document}$ \sum\limits_j {w_i x_i W} $\end{document} and x_i ? 0, integer; where v_i, w_i and W are known integers, and w_i (i = 1, 2, …, N) and W are positive. Various uses, including those in group theory and in other integer programming algorithms, as well as applications from the literature, are discussed. Dynamic programming, branch and bound, search enumeration, heuristic methods, and other solution techniques are presented. Computational experience, and extensions of the knapsack problem, such as to the multi-dimensional case, are also considered.     

Mean square invariant forecasters for the weibull distribution

Many techniques of forecasting are based upon extrapolation from time series. While such techniques have useful applications, they entail strong assumptions which are not explicitly enunciated. Furthermore, the time series approach not based on an indigenous forecast principle. The first attack from the present point of view was initiated by S. S. Wilks. Of particular interest over a wide range of operational situations in reliability, for example, is the behavior of the extremes of the Weibull and Gumbel distributions. Here we formulate forecasters for the minima of various forms of these distributions. The forecasters are determined for minimization in mean square of the distance. From n original observations the forecaster provides the minimum of the next m observations when the original distribution is maintained. For each of the forecasters developed, tables of efficiency have been calculated and included in the appendix. An explicit example has been included for one of the forecasters. Its performance has been demonstrated by the use of Monte Carlo technique. The results indicate that the forecaster can be used in practice with satisfactory results.     

B／S模式油料管理信息系统异构数据转换的实现

Internet的迅速发展和全军指挥自动化网的顺利建设使得油料管理信息系统由C／S模式向B／S模式发展成为需要,如何实现异构数据源的转换和备份是系统开发亟待解决的问题。提出了开发B／S模式油料管理信息系统时完成异构数据源转换的几种实现方法,重点介绍了如何设计程序将原始数据转换为SQL Server数据,如何以Access作为"中间层"实现SQL Senrer数据传递的问题,是Web环境下开发油料管理信息系统解决数据转换问题的一个有效方案。     

A Quarter Century of ‘Transitory Power-Sharing’. Lebanon’s Unfulfilled Ta’if Agreement of 1989 Revisited

Most countries of the Arab Mashrek are multi-ethnic and multi-sectarian. In recent years, most of them have experienced violent clashes between groups that frame their conflicts along ethnic-sectarian lines. This article investigates the Lebanese Ta’if Agreement of 1989 as a crucial case study of how to manage such conflicts through a transitory power-sharing arrangement. It presents several provisions of this agreement that adhere to three different approaches of how to deal with such conflicts: the consociational and the centripetal models of power-sharing as well as the integrationist paradigm. It thereby seeks to develop a theoretical argument about chances and risks of transitory power-sharing in deeply divided societies and derives some general lessons for managing conflicts in the Middle East.