高空高速目标测速系统的研究

系统论述了线阵CCD用于高空高速目标瞬时速度实时测量的总体设计思想、有关的硬件组成及关键技术, 并探讨了该系统的实际应用。     

对某自动机双路供弹机的分析

以某双路供弹机为研究对象，分析了火药燃气驱动、弹链供弹、横向移动式双路供弹机的工作原理和结构特点，通过对计算结果的分析得出，扭簧是供弹机构中不可缺少的构件，并对供弹方式提出了改进建议。     

基于非局部低秩和加权全变分的图像压缩感知重构算法

为准确有效地实现自然图像的压缩感知(CS)重构,该文提出一种基于图像非局部低秩(NLR)和加权全变分(WTV)的CS重构算法。该算法考虑图像的非局部自相似性(NSS)和局部光滑特性,对传统的全变分(TV)模型进行改进,只对图像的高频分量设置权重,并用一种差分曲率的边缘检测算子来构造权重系数。此外,算法以改进的TV模型与NLR模型为约束构建优化模型,并分别采用光滑非凸函数和软阈值函数来求解低秩和全变分优化问题,很好地利用了图像的自身性质,保护了图像的细节信息,并提高了算法的抗噪性和适应性。仿真结果表明,与基于NLR的CS算法相比,相同采样率下,该文所提算法的峰值信噪比最高可提高2.49 dB,且抗噪性更强,验证了算法的有效性。     

面向复杂表面物体的3D太赫兹成像技术

将逆合成孔径雷达(ISAR)技术应用到太赫兹频段,针对平滑表面物体和复杂表面物体扫描获取原始数据,并基于快速傅里叶变换对获取的三维数据进行处理,实现横向和径向的高分辨力太赫兹三维目标重建。通过在波数域对回波信号进行距离迁移补偿处理、插值处理,以及空域图像阈值去噪处理后,将目标的反射系数从三维空间中提取出来并保留其空间位置信息,从而完成三维目标重建。     

基于隐马尔可夫模型的机电系统机内测试虚警抑制

为解决系统间歇故障的诊断问题，利用连续隐马尔可夫模型，在对系统状态分析与建模的基础上，针对有间歇故障训练样本和无间歇故障训练样本两种情况，分别用不同的三个状态诊断方法进行诊断。结果表明两种方法都能有效地诊断间歇故障，达到降低BIT虚警的目的。     

基于X9241的瞄控台自动控制器设计

瞄控台自动控制器由AT98C2051、电桥和电压比较电路及数控电位器X9241组成.单片机根据电压比较电路敏感电桥两臂不平衡电压输出信号的正负极性控制X9241,实现电桥平衡和控制器的自动调节.X9241采用二线串行I2C总线与单片机传递数据.其软件由主程序、中断子程序组成.     

声品质技术探讨

伴随着中国的制造业发展,人们越发重视产品噪声对听众心理、生理的影响.从声品质遵照的心理声学理论基础、声品质常用的数据采集分析方法、声品质分析技术的实际应用及现阶段声品质技术的局限和相应的未来工作计划四个方面对声品质技术进行了探讨.     

高速深孔加工顶紧系统设计分析

在高速深孔加工中,其中影响加工可靠性的重要因素就是工件以及受油器,在不同的高速深孔加工过程中,对连接工件以及受油器的顶紧力的要求也是不一样的,对顶紧力的精度有着更高的要求.本文就高速深孔加工顶紧系统设计进行具体地分析,进而使该技术得到更好地应用.     

New and improved approaches for shared-path protection in WDM mesh networks

This paper investigates the problem of dynamic survivable lightpath provisioning in optical mesh networks employing wavelength-division multiplexing (WDM). In particular, we focus on shared-path protection because it is resource efficient due to the fact that backup paths can share wavelength links when their corresponding working paths are mutually diverse. Our main contributions are as follows. 1) First, we prove that the problem of finding an eligible pair of working and backup paths for a new lightpath request requiring shared-path protection under the current network state is NP-complete. 2) Then, we develop a heuristic, called CAFES, to compute a feasible solution with high probability. 3) Finally, we design another heuristic, called OPT, to optimize resource consumption for a given solution. The merits of our approaches are that they capture the essence of shared-path protection and approach to optimal solutions without enumerating paths. We evaluate the effectiveness of our heuristics and the results are found to be promising.     

Globally optimal transmitter placement for indoor wireless communication systems

A global optimization technique is applied to solve the optimal transmitter placement problem for indoor wireless systems. An efficient pattern search algorithm - DIviding RECTangles (DIRECT) of Jones et al.- has been connected to a parallel three-dimensional radio propagation ray tracing modeler running on a 200-node Beowulf cluster of Linux workstations. Surrogate functions for a parallel wideband code-division multiple-access (WCDMA) simulator were used to estimate the system performance for the global optimization algorithm. Power coverage and bit-error rate are considered as two different criteria for optimizing locations of a specified number of transmitters across the feasible region of the design space. This paper briefly describes the underlying radio propagation and WCDMA simulations and focuses on the design issues of the optimization loop.