一种新的CLEFIA多字节差分故障分析方法

阐述了CLEFIA分组密码算法及故障分析原理,根据在CLEFIA密码第r轮与第（r-2）轮注入多字节故障,提出了一种新改进的针对CLEFIA的多字节故障模型及分析方法,并通过软件仿真实验进行了验证。结果表明,CLEFIA算法的Feistel结构和差分S盒特性使其易遭受多字节故障攻击,而改进算法使得密钥的恢复效率大大提高。     

基于复杂表面形状的端铣切削力模型

以传统的端铣切削力模型为基础,针对复杂加工表面形状,提出了一种更加符合实际加工情况的端铣切削力模型。该模型的建立涉及到复杂表面形状的几何表示、不同刀具轨迹的描述和刀齿-工件接触计算等关键技术。通过对模拟结果进行分析,验证了所建端铣切削力模型的有效性。     

狭长受限空间油气爆炸关键现象研究

以汽油油气混合物为研究对象,在狭长密闭管道中进行了油气爆炸实验,通过压阻式传感器测试爆炸过程中的压强信号,得到狭长受限空间中油气爆炸的基本参数。通过对实验结果的对比分析,发现狭长受限空间内的油气爆炸可以分为4个阶段：平滑加速阶段、湍流发展阶段、振荡激化阶段和余波阶段;一定强度的湍流流场可抑制链化学反应速度和火焰传播速度;振荡激化阶段发生在管道末端。为狭长密闭空间内油气爆炸的预防和抑爆技术研究提供了参考。     

边防部队反恐怖作战心理训练问题初探

反恐作战心理训练是现代反恐怖作战行动中需要特别研究和解决的问题。阐述公安边防部队实施反恐作战心理训练的意义,分析公安边防部队反恐作战心理训练的基本方式方法,说明实施反恐心理训练必须注意把握的几个关键性问题。     

舰载雷达零位标校新法

对目前现有舰载火控雷达零位标校的方法和技术做了简单概述,提出了一种基于差分GPS、CCD、激光经纬仪等技术相结合的零位标校新法,给出了系统硬件组成和算法原理,对系统误差影响因素做了分析。实践标明此系统可以有效的克服由于舰体的摆动而对测量精度的影响,并极大的改善了标校的灵活性与机动性。标校系统测量真值位置精度优于50 cm,相应真值角度精度优于0.05 mrad,满足舰载雷达标校精度要求。     

大流量气体减压器振动问题研究

对大流量气体减压器工作过程中的振动故障进行分析,建立了减压器系统动态数学模型,进行了故障数值仿真,找到了简单有效的提高减压器输出响应稳定性的方法--减小控制腔入口面积,并得到试验验证.仿真结果还表明,大流量气体减压器的振动问题不仅和减压器本身设计参数有关,还和下游管路容积有关.     

基于LBDL逻辑的抗DPA攻击电路设计方法

动态差分逻辑是一种典型的电路级差分功耗攻击(DPA)防护技术.这种技术通过使逻辑门保持恒定的翻转率来降低电路功耗与数据信号之间的相关性.介绍了一种新型的、基于查找表(Look-Up-Table,LUT)结构的动态差分逻辑(LBDL),以及基于这种逻辑的集成电路设计方法.该设计方法仅需在传统的半定制设计流程中添加少量的替换操作就可以实现 ,因而比其他完全需要全定制设计的动态差分逻辑具有更好的实用性.而相对同样适用于半定制实现的动态差分逻辑 WDDL(Wave Dynamic Differential Logic),LBDL逻辑解决了逻辑门翻转时刻与数据信号之间的相关性,从而比WDDL逻辑具有更好的功耗恒定性.实验结果表明,该设计方法能够有效实现具有抗DPA攻击性能的电路.     

How pressure for change challenge military organizational characteristics

This article elaborates on how structural, normative and functional pressures for change may challenge military organizational characteristics. We problematize theoretically and exemplify empirically what consequences these pressures can have on military organizational characteristics, arguing that they constitute major challenges for managing in particular normative pressures for change. The empirical examples suggest that bureaucratic, hierarchical, narcissistic and greedy traits of the organization are challenged by normative pressures such as value changes and normalization. Another source of challenge is professionalization processes. Structural challenges, on the other hand, are managed by the organization and do not seem to inhibit the workings of organizational characteristics. The plausibility probe conducted questions the sustainability of military organizational characteristics in their traditional disguise, in particular due to legitimacy concerns. It is suggested that future research should be directed towards analyzing how military organizations manage pressure for change and whether their characteristics are questioned.     

Analysis of some critical aspects in hot machining of Ti-5553 superalloy: Experimental and FE analysis

In this study, a newly developed titanium superalloy, i.e., the Ti-5553 alloy has used for hot machining. This material replaced Ti-grade-5 alloy in the application of aerospace, automobile, and biomedical sector. However, similar to Ti-grade-5 alloy, the Ti-5553 alloy has a low thermal conductivity which makes it difficult-to-cut material categories hence, high tool wear, cutting force and bad surface finish. Hot machining of Ti-5553 has been studied at different machining condition (room and hot) using Deform-2D finite element analysis. The result from the simulation test was compared with the experimental value and reduction of cutting and thrust forces was observed. The experiment was carried out with the same input parameters as simulation, and good coherence between them observed. Additionally, cutting zone temperature, effective stress, etc. for both room and elevated the temperature are also discussed.     

拦截高速机动目标的捕获区及微分对策导引律

针对高速机动目标拦截场景,研究末制导段捕获区存在条件及微分对策导引律问题.建立弹目相对运动模型并引入控制动力学模型,采用终端投影方法对相对运动模型进行降阶处理;基于微分对策理论推导一种解析形式捕获区,并具体到直/气复合控制导弹对机动目标的拦截中,该捕获区的存在能够保证对任意机动目标进行准确捕获;重新选取性能指标,将目标...