CONSOLIDATING DEMOCRATIC CIVIL-MILITARY RELATIONS

Children have special protection under the South African constitution, including the right to safety, health and an environment conducive to their wellbeing and optimal development. Yet, firearms contribute significantly to the high incidence of deaths and injuries among South African children and in young males in their late teens. This case study is about the participation of the Child Health Policy Institute (CHPI) in a law reform process ultimately aimed at reducing firearm injuries and deaths in the country by exercising stricter gun control through legislation and other reforms. This feature briefly describes the political context in which the project was initiated, the research on firearm injuries and deaths in children conducted by the CHPI, and the dissemination of the research findings. The role of the CHPI as an academic institution within the Gun Control Alliance is also examined as are the lessons learnt in trying the bridge the gap between research and law reform.     

基于PXI的舰炮电气设备通用自动测试系统

采用虚拟仪器技术,并通过软件产生模拟信号拉制设备的运转,完成动态信号的提取,实现电气设备测试系统的研制.该系统具有通用性、高效性和易用性等特点,具有较好的实用价值.     

The Kurdistan Workers' Party (PKK) and popular support: counterterrorism towards an insurgency nature

The PKK has been a prolonged problem in Turkey, and various measures have been adopted to diminish and end the violence. In addition to the impacts on violence, these policies have also had an impact on public opinion and ethnic awareness of Kurds in Turkey. This article analyzes these policies and their effects on electoral support for the PKK by examining the vote shares of the pro-PKK political parties in national and local elections. It concludes that Turkey has conceptualized the issue solely as a problem of terrorism, but the goal, strategy, organization, and format of violence used by the PKK reflect the nature of an insurgency. Therefore, it is argued that Turkey, by ignoring the insurgency features, has disregarded the legitimate parts of the cause and related popular support, and thus has responded mostly with deterrent measures apart from the reforms of recent years. Results have shown that policies of deterrence culminated in a steady level of support for the PKK indicating that low level of legitimacy – as they were perceived by the people – of the policies resulted in viable popular and political support for the PKK. Despite the recent accommodative reforms, the existence of pro-PKK parties rallying electoral support in the political arena provided sustained level activities in the conventional politics in Turkey's municipal and national political system, in which they pursue pro-PKK agendas, such as ‘Autonomy’ and ‘Confederation’ as well as activities to increase the distinction in identity around the ethnic consciousness for more popular support. Yet, no clear pattern is identified between violence level and popular support in the macro-scale.     

舰炮武器系统最大有效射程研究

舰炮武器系统最大有效射程是指系统在规定的射击条件下,对规定目标,使用规定弹药射击时能达到规定射击效力指标要求的最大作用距离。系统使用不同的弹药对付不同类型目标,最大有效射程是不同的。本文界定了舰炮武器系统最大射程和最大有效射程的关系,从舰炮武器系统弹丸存速、毁伤能力、系统精度及系统稳定性等方面入手,分析了影响系统对空和对海(岸)最大有效射程的各种因素,并提出了确定最大有效射程的方法和准则,为舰炮武器系统设计及使用提供了有力的理论基础。     

Colonel Hawker and Durs Egg: an unrecorded wildfowling gun,his famous two-barrelled punt gun and a passion for fowling

Abstract

A newly recorded wildfowling gun of Col. Peter Hawker and the history of his double-barrelled punt gun, both made by Durs Egg but the punt gun also receiving the attention of William Fullerd, Joe Manton, Westley Richards, Daniel Long of Andover and Thomas Parsons of Salisbury. Used in the waters off Keyhaven, Hants., where he had built a cottage. Elijah Buckle, professional wildfowler, helped design his punt and its carriage as well as other stanchion guns.     

Development of multi-physics numerical simulation model to investigate thermo-mechanical fatigue crack propagation in an autofrettaged gun barrel

In this research, a detailed multi-physics study has been carried out by numerically simulating a solid fractured gun barrel for 20 thermo-mechanical cycles. The numerical model is based on thermal effects, mechanical stress fields and fatigue crack mechanics. Elastic-plastic material data of modified AISI 4340 at temperatures ranging from 25 to 1200 °C and at strain rates of 4, 16, 32 and 48 s⁻¹ was acquired from high-temperature compression tests. This was used as material property data in the simulation model. The boundary conditions applied are kept similar to the working gun barrel during continuous firing. A methodology has been provided to define thermo-mechanically active surface-to-surface type interface between the crack faces for a better approximation of stresses at the crack tip. Comparison of results from non-autofrettaged and autofrettaged simulation models provide useful information about the evolution of strains and stresses in the barrel at different points under combined thermo-mechanical loading cycles in both cases. The effect of thermal fatigue under already induced compressive yield due to autofrettage and the progressive degradation of the accumulated stresses due to thermo-mechanical cyclic loads on the internal surface of the gun barrel (mimicking the continuous firing scenario) has been analyzed. Comparison between energy release rate at tips of varying crack lengths due to cyclic thermo-mechanical loading in the non-autofrettaged and autofrettaged gun has been carried out.     

基于ADAMS和Matlab的大口径舰炮发射系统动力学仿真

利用ADAMS和Matlab/Simulink两大软件的信息交互功能,将ADAMS中的全炮动力学仿真模型生成ADAMS_SUB模块,并将其嵌入联合后坐系统仿真模型中;通过ADAMS和 Matlab/Simulink同步运行对全炮进行发射动力学联合仿真,模拟大口径舰炮发射的全过程,分析全炮的动态响应.对全炮发射动力学联合仿真结果进行后处理分析,观察炮口扰动曲线,进行稳定性分析和炮口扰动分析.根据分析结果,对所建模型及仿真模块进行评价,结果表明,仿真结果与靶场试验数据基本吻合,为物理样机的研制提供了重要的理论参考依据.     

Effects of module number and firing condition on charge thermal safety in gun chamber

Thermal safety of modular charge which is fed into and retained in the chamber after gun fires consecutively is first investigated with cook-off method.A two-dimensional cook-off model of modular charge in gun chamber is established and the cook-off process of modular charge in gun chamber is numerically simulated.Then the effects of module number and firing condition on charge thermal safety are evaluated by researching the cook-off response characteristics of modules.The results show that,under conditions of different module numbers the cook-off responses all occur on the module closest to the boundary of missile,and the single-base propellants located at the inner surface of cartridge ignite first.When the number of loaded module changes from 1 to 6,the cook-off response temperatures vary little,only in a small range of 478.1 K-482.4 K.The cook-off response times decrease logarithmically in the range of 211.2 s-166.7 s with the increasing length of residual air gap in gun chamber.The simulation results are well matched with the experimental data.Furthermore,different firing conditions have great influence on the cook-off response time,minor influence on the initial response position and little in-fluence on the response temperature.Under the three conditions of consecutive 32 launches with 5 rounds/min,43 launches with 1 round/min,and 41 launches with different firing frequencies,the cook-off response temperatures are 479.2 K,481.1 K and 479.9 K respectively and the response times are 709.2 s,211.2 s and 214.4 s respectively.The response position is near the middle area of the inner cartridge surface in the former condition and near the right area in the latter two conditions.     

Myopic Government and Strategic Rebels: Exchange and Escalation of Violence

This study presents a model in which the innate inability of a government to fully comprehend the ramifications of its actions, herein referred to as the myopia of the government, leads to underinvestment in counterinsurgency measures and examines the nature of exchange of violence between the government and rebels. While the idea that voters’ or a government’s myopia leads to myopic policies is well established in the related literature, surprisingly, it has never been incorporated into conflict studies. As far as we are aware, this is the first ever study that analyzes the effects of a government’s myopia on the exchange and eventual escalation of violence when the rebels are in their trying stages and shows situations in which the two-sided violence could be either strategic substitutes or complements. The results suggest that in case of a foresighted government, the acts of two-sided violence are strategic complements. When the government is myopic, however, the rebels’ use of violence is a strategic substitute for the government’s violence. The trade-off, according to the model, lies in exchanging higher levels of violence for lower chances of revolt.     

随动系统智能测量结构的实现

介绍了舰炮随动系统的一种智能测量结构 .它采用微机控制技术 ,能自动对随动系统的多项技术性能进行定量测试 .通过引入虚拟仪器设计思想 ,内嵌数据库和软件示波器 ,实现了对正弦机、光线示波器和振子箱等人工测量仪器的替代     

COIN and civilian collaterals: patterns of violence in Afghanistan, 2004–2009

Theories and counterinsurgency doctrines emphasize the importance of avoiding civilian casualties. Yet, many operations produce large numbers of so-called collateral civilian deaths. I present two competing arguments for when collateral deaths occur. One the one hand, they could be the unintentional result of offensives when trying to maintain force protection; on the other hand, they could be the result of a deliberate choice of relying on indiscriminate violence when pressured on the battlefield. I use new data on violence in Afghanistan 2004–2009, disaggregated by province and month, to examine what type of battlefield dynamics are more likely to produce high levels of collateral civilian casualties. The results show that civilian casualties are particularly high after counterinsurgency forces suffer losses in combat.     

Numerical investigation of dynamic interaction with projectile and harmonic behaviour for T-finned machine gun barrels

Machine gun barrels differ from their rifle counterparts in terms of profile. To support high rates of sustained fire, machine gun barrels are made thicker in order to dissipate more heat and maintain their flexural rigidity and thus accuracy, but on other hand they also contribute in weight addition to weapon. This investigation deals with comparison between a conventional machine gun barrel and an improved innovative design having T-fins, both having same weight and chambered in 5.56 × 45 NATO ammunition, to compare their structural and harmonic characteristics which were parameterized by factors such as modal spectrum, directional deformation at muzzle ends during a single shot fire and harmonic behaviour at corresponding range of exciting frequencies. The solid models of both the barrels having same weight, were created using Solidworks. The continuous input data functions were generated by MATLAB using the field tested discreet data points. The generated velocity-distance functions were converted into time dependent functions using integration algorithms to calculate transient parameters such as time steps, excitation frequency range, angle of rotation of projectile and its angular velocity. The dynamic condition simulated the varying nature of forces due to eccentricity in projectile and this data was fed to a time step study using ANSYS transient structural work bench followed by modal and harmonic analysis. The results showed a significant reduction in muzzle end deformation which thus proved that the T-finned barrel, although had same weight as that of the conventional one, but had better structural and harmonic characteristics, and hence it would inherit better firing accuracy.     

国外火炮定位雷达的现状和发展趋势

主要描述了国外火炮定位雷达的研制现状,对美国研制的Firefinder系列雷达,俄罗斯研制的Zoopark-1雷达,英、法、德等国联合研制的COBRA雷达以及瑞典和挪威联合研制的AR THUR雷达等几种火炮定位雷达的特点、主要技术指标及市场销售情况做了简要的介绍,最后总结了国外火炮定位雷达的最新发展趋势。     

大中口径舰炮敏捷供弹系统虚拟样机仿真研究

文中提出了一套完整的大中口径舰炮敏捷供弹系统。应用三维实体建模软件PRO/E完成了整个供弹系统各个子系统的模型设计及建立;进行了装配检查,排除了零部件之间的干涉,完善了零部件设计;再利用PRO/E和ADAMS相结合,建立供弹系统各部分的驱动系统,并与实体模型结合,对此系统进行机构的运动学、动力学和驱动系统仿真,对设计的可行性和合理性进行深入研究.通过以上研究,建立了一个完整的大中口径舰炮敏捷供弹系统虚拟样机,为供弹系统的进一步深入研究以及实际生产提供了坚实的基础,同时给军械设计提供了一条高效率、低成本的设计方法.     

速射转管炮射击精度的影响因素及对策

速射转管炮作为近程反导武器系统的重要一员,射击精度影响着其最终防御效果,通过对速射转管炮特点及其射击偏差机理的分析,研究了转管炮射击过程中身管转速、弹丸初速等多种因素对射击精度的影响,并在转管炮初始设计、弹道模型和校射等方面提出了修正误差、提高射击精度的方法。     

Aerodynamics analysis of a hypersonic electromagnetic gun launched projectile

A hypersonic aerodynamics analysis of an electromagnetic gun (EM gun) launched projectile configuration is undertaken in order to ameliorate the basic aerodynamic characteristics in comparison with the regular projectile layout. Static margin and pendulum motion analysis models have been applied to evaluate the flight stability of a new airframe configuration. With a steady state computational fluid dynamics (CFD) simulation, the basic density, pressure and velocity contours of the EM gun projectile flow field at Mach number 5.0, 6.0 and 7.0 (angle of attack = 0°) have been analyzed. Furthermore, the static margin values are enhanced dramatically for the EM gun projectile with configuration optimization. Drag, lift and pitch property variations are all illustrated with the changes of Mach number and angle of attack. A particle ballistic calculation was completed for the pendulum analysis. The results show that the configuration optimized projectile, launched from the EM gun at Mach number 5.0 to 7.0, acts in a much more stable way than the projectiles with regular aerodynamic layout.     

基于BP神经网络的舰炮武器系统综合保障性能评价

通过对舰炮武器系统的分析,建立舰炮武器系统综合保障性能评价的指标体系。把神经网络的相关知识应用到舰炮武器系统综合保障性能评价中,得到了相应的BP神经网络评价模型。通过一些舰炮武器系统的实例计算,验证了模型的正确性,为舰炮武器系统的研制和改进提供了一定的参考依据。     

舰炮系统的分布式交互仿真概述

论述了舰炮系统的分布式交互仿真 (DIS) ,建立了舰炮系统DIS模型并简述了各仿真模块的功能     

舰炮振动的高斯最小拘束分析方法

根据多刚体动力学理论,采用高斯最小拘束方法,建立了复杂舰炮系统的动力学方程,并结合相关实验参数进行了全炮系统射击过程的数值仿真.仿真结果表明,甲板刚度为影响炮口振动的主要因素,舰炮射击性能的改善主要体现在甲板的刚度上;恰当设计高低机的刚度,能有效改善舰炮系统的振动性能.计算模型、方法及结果对相关的工程研究和计算具有一定的参考价值,并为今后进行舰炮的整体设计提供了一定的理论基础.