改进的双Householder变换及其在快速辨识状态空间模型中的应用

系统辨识广泛应用于工程实践面临的主要问题是算法的快速性,状态空间模型辨识更是如此,本文提出的改进的双Householder变换就是利用数据矩阵的特殊结构Hankel矩阵和Toiplitz矩阵;再利用移位算子的性质,对数据矩阵实施变换,从而快速地求解矩阵的逆和正交补,进而可以提高辨识算法的快速性和精确度     

Noninvasive glucose monitoring in vivo with an optical heterodyne polarimeter

An amplitude-sensitive optical heterodyne polarimeter was set up to monitor noninvasively the aqueous glucose concentration in a rabbit's eye. A Zeeman laser in conjunction with a Glan-Thompson analyzer was used to generate an optical heterodyne signal. The amplitude of the heterodyne signal linearly related to the optical rotation angle of the aqueous glucose. The concentration of the aqueous glucose in a rabbit's eyeball was measured in vivo. There was a 30-min time delay between observations of aqueous glucose and blood glucose. The detection capability and the reproducibility of the experiment are demonstrated and discussed.     

Graphic analysis of the effective reflectivity of antireflection-coated films on diode facets

The wavelength dependence of the reflectivity of AR-coated facets and carrier density in relation to peak wavelength of the gain profile have been taken into consideration to study a one-facet AR-coated semiconductor diode laser. A graphic analysis method is developed to study cases in which analytical expressions of the reflectivity curves cannot be extracted. Results show that the upper bound of the carrier density that can be established inside the diode is generally (sometimes to a considerable degree) smaller than that determined by the claimed minimum reflectivity if the spectral width of the reflectivity curve cannot be regarded as infinite. This implies that the effective reflectivity of the AR-coated facet is generally larger than the claimed minimum reflectivity. To increase the effectiveness of AR film, it is essential to maintain tight control of the wavelength at which the reflectivity curve is minimum.     

有载调压变压器调整对电力系统电压稳定性的影响

本文利用分叉理论,在静态范围讨论了有载调压变压器分接头调整电力系统电压稳定性影响问题,研究表明,对应于不同负荷模型,有载调压变器变比变化对电压失稳静分叉点的“迁移”方向,最终位置,调压效应产生很大影响,此外,研究发现,一些负荷模型在一定负载区域内,有载调压变压器分接头调整还会产生复杂的“混合调压效应”现象。     

Protein crystal growth in microgravity using a liquid/liquid diffusion method

Crystallization of proteins by liquid liquid diffusion method was performed in microgravity using the MDA Minilab aboard the US Space Shuttle. Three proteins, namely lysozyme, trichosanthin, and a new lechin, were crystallized in the space experiment. In contrast to the results of space experiments with a tube-like vapor diffusion method, the crystallization conditions for growing better crystals in space are remarkably different from the conditions optimized on earth. This may be due to difficulties in ground optimization, which are caused by gravity-dependent phenomena, in particular the specific convective flow occurring with liquid liquid diffusion.     

Restricted Information from Nonadaptive Queries to NP

We investigate classes of sets that can be decided by bounded truth-table reductions to an NP set in which evaluators donothave full access to the answers to the queries but get only restricted information such as the number of queries that are in the oracle set or even just this number modulom, for somem?2. We also investigate the case in which evaluators are nondeterministic. We show that when we vary the information that the evaluators get, this can change the resulting power of the evaluators. We locate all these classes within levels of the Boolean hierarchy which allows us to compare the complexity of such classes.     

单线激光雷达摆动扫描装置及其控制

为弥补单线激光雷达在获取障碍物的几何形状信息上能力较弱的缺点,采用了一种基于无急回特性曲柄摇杆机构的ALV车载激光雷达摆动装置;分析了曲柄摇杆机构的运动特点及无急回特性装置杆长条件;为实现激光雷达在车体平面匀速扫描功能,使用多项式拟合的方法计算出驱动曲柄旋转的直流电机转速与激光雷达摆角之间的关系;建立了系统数学模型,设计了直流电机转速PID控制器,仿真结果表明当负荷力矩不断变化时,系统响应速度快,跟踪误差小;实验数据证明该激光雷达摆动装置实现了期望功能,性能可靠,能够满足ALV主动环境感知的要求.     

一种陆地车辆对抗演示系统设计

设计一种陆地车辆对抗演示系统,该系统主要包括图像采集单元、上位机控制处理平台单元、无线传输单元、驱动控制单元、对抗判决系统单元和敌我识别系统单元;设计中采用4辆车辆(2对2模式)进行对抗实验,实验表明设计的陆地车辆对抗演示系统可以实现对前方环境和对方对阵情况的实时图像获取和处理、显示、无线收发控制、计算、轨迹控制、特征识别、定位、文件管理、数据传输、生命值显示以及声音报警等功能;实验对抗结果:乙方两辆车4个生命值显示灯全部熄灭,甲方对抗胜利.     

基于AVR单片机的多舵机控制系统设计及仿真

舵机是机器人、机电系统和航模的重要执行机构;文章介绍了一种以ATmega16为核心的多舵机控制系统.利用单片机内部定时器,采用分时控制思想,用单片机实现多路PWM输出;系统的设计主要分为总体方案设计,硬件设计和软件设计部分,其中每一部分均采用模块化设计原则;系统总体设计遵循了可靠、简单、实用的原则,实验结果验证了方法的可行性和有效性,所提出的方法已经应用于多舵机的系统中.     

基于小波变换数字图像水印系统的抗攻击性研究

针对计算机网络不断发展中多媒体版权难以保护问题,分析了数字水印的评估标准和数字图像小波分解原理;设计了一种基于DWT的二值水印算法系统,实验结果验证了该算法的有效性,可靠性、抗攻击性、不可见性;能够为媒体信息在防伪、防篡改、认证、保障数据安全和完整性等方面提供有效的技术保障.