9/11: WHAT DID WE KNOW AND WHEN DID WE KNOW IT?

In February 1998, Osama Bin Laden published a signed statement calling for a fatwa against the United States for its having ‘declared war against God’. As we now know, the fatwa resulted in the unprecedented attack of 9/11. The issue of whether or not 9/11 was in any way predictable culminated in the public debate between Richard Clarke, former CIA Director George Tenet and the White House. This paper examines whether there was any evidence of a structural change in the terrorism data at or after February 1998 but prior to June 2001, controlling for the possibility of other breaks in earlier periods. In doing so, we use the standard Bai–Perron procedure and our sequential importance sampling (SIS) Markov Chain Monte Carlo (MCMC) method for identifying an unknown number of breaks at unknown dates. We conclude that sophisticated statistical time‐series analysis would not have predicted 9/11.     

TERRORISM AND TOURISM: THE CASE OF TURKEY

Using a time series method called ‘transfer function’, this paper examines the effect of terrorism on tourism in Turkey. The results indicate that there exists a negative but small impact of terrorism, which is observed within approximately one year. However, terrorist attacks in Turkey have accounted for a reduction of six million foreign tourists over the last nine years. Moreover, the economic cost of terrorism in the tourism industry was more than $700 million in 2006. However, terrorist attacks in continental Europe and America, and an active war involving a neighboring country, had no effects on tourism in Turkey.     

Remaking the military industrial relationship: A French‐American comparison

Defense industrial complexes in leading Cold War nations have downsized and reallocated resources to other productive activities in the 1990s. In this paper, we analyze the experience of two key countries ‐ the US and France. Comparing the two countries, we find similar outcomes in budgetary retrenchment and large firm restructuring but marked differences in the pace of downsizing and diversification among small and medium‐sized firms. We hypothesize that three sets of contextual differences may explain these differences: 1) institutional differences in the way that the State bureaucracies ‐ the Pentagon and the French Délégation générale pour l'armement (DGA) ‐ oversee defense industrial matters, 2) differences in military industry ownership and firm size patterns, and 3) differences in the regional distribution of defense industrial capacity and associated regional policies. In closing, we note that the two countries’ defense industrial complexes are becoming more alike and speculate on the significance of invidious competition and interactions between them. We address briefly the future of French/American arms industrial competition and cooperation, given the trend towards transnational security arrangements and defense industry globalization     

Stopping Nuclear Traffic

The exploits of the A.Q. Khan nuclear network have received significant attention in the last three years. Gordon Corera's recent book, Shopping for Bombs, is an important addition to the existing literature. In this book, the author explores how Khan became a nuclear supplier and why his network was able to flourish for so many years. In his analysis, Corera examines relevant domestic and international political circumstances that affected Khan's rise and ultimate fall. The author also gives a compelling account of the international investigation that shut down this network in 2004 and warns that Khan's network will not be the last to challenge international nonproliferation regimes. Despite a few gaps in the book's narrative and analysis, Shopping for Bombs is an important source of insight into the activities of Khan and his network.     

Notes on Cataneo's Scale,Some Gunners' Daggers and a Gunners' Rule

Abstract

Cataneo's scale, published in 1571, relates the weight of shot to the internal muzzle diameter of guns ranging between 0.04–0.21 m. Plots of calculated shot density versus muzzle diameter suggest that diameters of 0.10 m and above apply to iron shot and those below apply to lead and lead/iron composite shot. Similar plots are used to compare Cataneo's scale with other contemporary scales and with scales engraved on the blades of five Italian gunners' daggers dating to around 1650. Variations and errors in the daggers' scales might suggest a symbolic rather than a practical role; nevertheless there is remarkable consistency with Cataneo's scale in the shape of the plots in spite of the considerable length of time after its publication. A simple wooden scale from the Spanish Armada ship La Trinidad Valencera also confirms to Cataneo's general pattern although there appears to be a fundamental error in its mathematical construction.     

界面热阻对金刚石/银复合材料导热率的影响

研究了金刚石／银复合材料的导热率与金刚石的含量、粒度等之间的关系,着重讨论了界面热阻对复合材料导热率的影响。并阐述了金刚石表面镀钛,能有效改善金刚石对银的润湿性,降低界面热阻,从而提高金刚石／银复合材料的导热率。     

基于CNN的三相逆变器开路故障诊断及其样本条件分析

为了合理选择样本条件以实现高效的智能化诊断,以及克服智能化方法中传统反向传播(back propagation, BP)网络权值较多、局部信息提取能力不足的问题,对基于卷积神经网络(convolutional neural network, CNN)的开路故障诊断方法进行研究,并以典型的三相两电平逆变器为具体对象,着重分析样本时长、样本数量变化时,CNN方法相较于BP网络方法在网络权值数量、训练稳定性、诊断准确率上的量化优势。结果表明,基于CNN的方法可在权值数量远少于BP网络方法的情况下构建深度更深的诊断模型,并在更短样本时长、更少训练样本数量下实现高效、准确的开路故障诊断。     

大学英语四、六级考试最新改革特点及对策研究

2013年最新改革后的大学英语四、六级考试,在考试内容、分值比例和难度系数等方面都作了诸多调整,呈现出新的特点。结合此次改革特点和对某军校150名学员展开的问卷调查,提出三大对策：利用考试“反拔效应”,引发学员对于输出性技能的重视;充分重视翻译策略讲解,加强中国文化渗透;努力培养学员自主学习意识养成,提高学员自我听力训练量。     

导弹初始大角度转弯复合控制研究

基于直接力/气动力复合控制方法,研究了导弹初始快速大角度转弯问题。给出了直/气复合控制回路稳定性分析方法,并应用极点配置求得系统控制参数。最后对直/气复合控制回路稳定性进行了分析,对其时域跟踪进行了数学仿真。仿真结果表明,提出的控制方法可以提高系统转弯快速性,验证了复合控制方法的可行性。     

Capable Companies or Changing Markets? Explaining the Export Performance of Firms in the Defence Industry

The paper presents an analysis of the factors explaining the export performance of firms in the defence sector. We focus on the case of Norway, and make use of two complementary methodologies: the first is based on econometric firm-level data analysis for the whole population of defence companies, and the second is based on qualitative case study research on the three most important defence export products (weapon stations, ammunition and electronics). Our empirical results highlight the importance of four major success factors for exporting firms: (1) the participation in offset agreements; (2) the ability to focus on their set of core competencies; (3) their R&D activities and interactions with the public S&T system; and (4) demand opportunities and, relatedly, user-producer interactions.