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。     

MFSK/FFH系统分集合并算法性能对比研究

推导了部分频带干扰最佳干扰系数表达式并进行了仿真验证,描述了多进制频移键控/快跳频(MFSK/FFH)系统、衰落信道和分集合并算法模型,在最坏部分频带干扰和衰落信道下,仿真对比了MFSK/FFH系统采用线性分集合并、限幅线性分集合并、自归一分集合并、排序统计自归一分集合并、乘积分集合并5种分集合并算法时的误码率性能,结果表明:在最坏部分频带干扰和衰落信道下,线性合并性能较差,其他4种算法性能较为相似,Rayleigh衰落信道中排序统计自归一分集合并和乘积分集合并算法性能最优。     

基于WindowsCE的嵌入式漏磁检测仪ADC驱动程序设计

描述了基于WindowsCE的嵌入式漏磁检测仪总体结构设计,介绍了WindowsCE下设备驱动程序模型,并结合$3C2440A处理器的ADC驱动程序设计,详细阐述了基于Windows的流接口驱动程序的设计方法。实验结果表明：利用该方法设计的ADC驱动程序高效可靠,可以为开发类似设备驱动程序提供参考。     

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.     

基于移频卷积的合成孔径雷达干扰技术研究

针对合成孔径雷达(SAR)信号存在着距离和多普勒频率之间耦合的特点,提出了一种利用DRFM进行SAR雷达信号的存储,并加入多普勒频移进行脉冲叠加噪声卷积的SAR干扰新方法.通过真目标回波与滞后方向的假目标回波交叠,形成了类似于噪声的距离维压制干扰;在复制的干扰脉冲上叠加一个窄带的噪声信号,造成方位维的模糊来进行方位维干扰,达到对SAR的二维相参压制干扰效果.     

Ukrainian and Belorussian dimensions of Turkmenistan foreign policy: small states in a multipolar world

As the USA continues to decline both in relative and absolute terms, the global order emerges where no center of power exists. This creates a complicated and instable geopolitical situation where small states could act behind the back of the great powers. The relationship between Turkmenistan and Ukraine is the example of this sort of relationship. Whereas Ukraine wants to get cheap gas, Turkmenistan wants to find the way to sell its gas to the West. It looks as though both countries pay little attention to Russian objection and act without direct help from either the USA or other great powers.     

Soldiers contra diplomats: Britain’s role in the Zimbabwe/Rhodesia ceasefire (1979–1980) reconsidered

Abstract

This article re-examines part of the literature on Britain’s role in the December 1979 to March 1980 Zimbabwe/Rhodesia ceasefire. The ceasefire ushered in an era of peace after a protracted internal war and it was an integral part of the transition from colonial white minority rule, towards black majority independence. Scholars present Britain’s success in brokering and monitoring the Zimbabwe/Rhodesia ceasefire as the result of its judicious and accordant management of the road to peace. However, this article argues that in fact deep internal divisions plagued the British managers of the ceasefire. Internal divisions centred on authority struggles between diplomats and military actors, conflicting personalities, discordant approaches to and goals in the ceasefire, and inter-institutional rivalry between the Foreign Office and Ministry of Defence. The article concludes that Britain only managed the ceasefire effectively because its military’s independence, political nous, and competence ultimately prevailed over the injudicious views and machinations of diplomats.     

空气/煤油/水燃气发生器点火特性试验研究

燃气发生器是超燃冲压发动机地面试验系统中的关键设备,为提高系统安全性和经济性设计了空气/煤油/水燃气发生器,在富燃状态下进行了一系列点火试验,试验结果表明：该型燃气发生器,实现可靠点火的余氧系数下限为0.51;水的加入使得化学反应速率和火焰传播速度降低,燃气发生器点火和火焰稳定困难,提高余氧系数可以提高点火可靠性。同时水的加入容易引起燃烧不稳定,通过提高余氧系数可消除低频不稳定燃烧。