Counter-Insurgency in Pakistan: The Role of Legitimacy

The Pakistani security forces have won their fight against the insurgency of the Pakistani Taliban, though terrorism will remain a serious problem for the foreseeable future. Victory was won not chiefly on the basis of new tactics, but of the recovery of legitimacy for the campaign among the population and the armed forces. This occurred when the war came to be seen as one waged not in the interests of the USA, but for the defence of Pakistan. In Balochistan, the nationalist insurgency has been different from and weaker than that of the Taliban—but may prove longer lasting. Military tactics in Balochistan have closely resembled those of the British Raj, and have been based with some success on fomenting tribal divisions and co-opting tribal elites.     

Insurgency and Violent Extremism in Pakistan

Pakistan has an uneven history of dealing with insurgencies and extremism. This article identifies the various campaigns and policies employed to defeat militants and deal with violent extremism. It describes the major anti-state groups and how Pakistan’s military and civilian leaders, relying on the related strategies of selectivity, gradualism and containment, have allowed militancy and terrorism to thrive. This article finds that while the elites and the public may have belatedly come to appreciate the existential internal threats these groups pose to the country, there are strong reasons to doubt the state’s full commitment to its promises to take meaningful action.     

无人机规避或跟踪空中目标的自适应运动导引方法

无人机规避或跟踪空中目标可以看作是一个非线性运动导引控制问题。针对这类任务中无人机和目标存在高机动性、高时敏性等特点,提出了一种基于Lyapunov稳定性理论的无人机规避或跟踪目标运动导引方法。构建了基于精细时间运动导引方法的无人机规避或跟踪空中目标问题求解框架,并将无人机碰撞规避和机动目标跟踪问题分别转化为到达虚拟目标点和与虚拟目标点交会的问题。针对碰撞规避问题,将其转化为实现平行导引的控制问题,基于Lyapunov稳定性理论设计了无人机碰撞规避导引律。针对机动目标跟踪问题,在碰撞规避基础上,根据目标点交会的要求设计了相应的目标跟踪导引律。在Gazebo平台上开展了仿真验证实验,实验结果表明:所提方法能够有效避免大过载情况的出现,并具有较强的时变和参数适应性。     

凹障碍超宽带SAR图像特征分析

野外环境下的凹障碍感知一直是地面无人作战平台环境感知面临的难题,长期以来常规传感器,例如立体视觉、红外相机和激光雷达,都没有取得好的效果。超宽带合成孔径雷达作为一种全天时、全天候的高分辨率雷达,在目标感知方面得到了广泛的运用。基于超宽带合成孔径雷达感知凹障碍是一种有效的感知手段,阐述了凹障碍的雷达成像几何,利用MATLAB模拟仿真合成孔径雷达数据获得了凹障碍图像,分析得出了凹障碍在雷达图像表现出由阴影区和光亮区紧密相连的特征,并通过实测数据成像获得的凹障碍图像结果,对凹障碍雷达图像特征进行了进一步的验证。     

伞翼无人机线性自抗扰高度控制

针对伞翼无人机参数不确定性和复杂环境干扰敏感的问题,提出一种伞翼无人机线性自抗扰(Linear Active Disturbance Rejection Control,LADRC)高度控制方法。建立伞翼无人机8自由度飞行动力学模型,并引入风场和降雨模型以更加准确地模拟真实飞行环境。基于LADRC确定总体控制架构,设计线性扩张状态观测器对所有扰动进行估计,并引入误差反馈率在控制中实时补偿。使用该控制方法在多种扰动工况下进行伞翼无人机高度控制仿真实验。仿真结果表明,基于LADRC的高度控制方法能够有效克服内扰和外扰的影响,实现高精度高度控制;与传统PID控制效果相比,LADRC控制器具有更好的抗扰能力和鲁棒性。     

Missile defense and strategic stability: Terminal High Altitude Area Defense (THAAD) in South Korea

South Korea is threatened by its troubled relationship with North Korea. North Korea possesses a large cache of missiles as well as chemical and biological weapons, and the future potential to mount nuclear weapons on its missiles. The United States is also challenged because of its defense commitments to Seoul. As a countermeasure, the United States and South Korea decided to deploy Terminal High Altitude Area Defense (THAAD) missile defenses in South Korea. However, China has objected. Chinese scholars believe the THAAD radar would be able to track Chinese inter-continental ballistic missiles, thereby weakening their deterrent. A technical analysis does not support this assertion. However, it is vital for South Korea, given its proximity and economic interdependence, to reassure China. South Korea should highlight that THAAD will be deployed by the United States Forces Korea and is not a commitment by Seoul to become part of U.S.-led missile defenses in the Asia-Pacific.     

The NATO Response Force: A qualified failure no more?

With much fanfare, NATO declared its rapid reaction force—the NATO Response Force (NRF)—an Initial Operational Capability in 2004. This article addresses four questions: Where did the NRF come from? What does it look like in 2017? What have been the major obstacles for the NRF fulfilling its promises? And where is the NRF likely to go? The article holds two main arguments. First, due to inadequate fill-rates and disagreements as to the force’s operational role, the NRF was for many years a “qualified failure.” The force failed to become the operational tool envisioned by the allies in 2002. While not without effect, it fell hostage to the harsh reality of the expeditionary wars of Iraq and Afghanistan. Second, the NRF is off to a fresh beginning and will likely be considered at least a partial success by the allies in the years to come.     

领悟社会支持与高中生学习投入的关系:自尊和未来教育规划的链式中介作用

目的:探究领悟社会支持对学习投入的影响,以及自尊和未来教育规划的链式中介效应。方法:采用领悟社会支持量表、自尊量表、未来教育规划问卷和学习投入量表,对446名高中生进行施测。结果:①各变量两两之间均存在显著地正相关(r=0.32~0.50,p<0.001);②领悟社会支持能正向预测高中生学习投入;③在领悟社会支持对高中生学习投入的预测中存在三条路径:一是自尊的中介作用;二是未来教育规划的中介作用;三是自尊和未来教育规划的链式中介作用,效果值分别为:14.81%,27.78%和16.67%。结论:领悟社会支持不仅直接影响高中生学习投入,还通过自尊和未来教育规划影响高中生学习投入。     

One-step synthesis of FeO(OH) nanoparticles by electric explosion of iron wire underwater

In this study,we investigated electric explosion of iron wire in distilled water with different energy input adjusted by charging voltage.The as-prepared samples were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS),showing the presence of iron and multiple iron-based compounds oxides with contents influenced by the experimental conditions.In particular,pure FeO(OH) nanoparticles were obtained using electric explosion of iron wire with energy input of 1125 J at charging voltage of 15 kV.Analysis of discharge current and resistive voltage data indicate that the high energy input induced by strong plasma discharge at high charging voltage is a key factor to form FeO(OH).This study presents a one-step method to synthesize FeO(OH) nanoparticles using electric explosion of iron wire.     

The investigation of NTO/HMX-based plastic-bonded explosives and its safety performance

3-nitro-1,2,4-triazol-5-one (NTO) is the main component of insensitive munitions (IM) formulation because of its outstanding insensitive properties.In this paper,a series of NTO/HMX-based composite explosives were prepared and characterized.The study focuses on the effect of NTO on the performance of the formulations,especially the safety performance.The results revealed that the mechanical sensi-tivity of formulations was associated with NTO content,as well as the thermal conductivity,specific heat capacity and Arrhenius parameters.Then,the high amount of NTO using in formulation was proved to be helpful for NTO/HMX-based formulation to exhibit good thermal safety.Besides,by accelerating rate calorimeter (ARC) and a modified cook-offequipment,the pressure and pressure rise rate were proved as the important indicator for judging the thermal safety performance in confined spaces.Finally,the numerical simulation was used as a credible method for predicting the respond temperature of cook-off experiment.