基于混合不确定建模的主动悬架鲁棒μ综合控制分析

利用线性分式变换理论对二自由度车辆主动悬架系统进行混合不确定建模分析,通过结构奇异值理论和D-K迭代设计过程,设计了鲁棒μ综合控制器.仿真结果表明:在给定的不确定范围内,鲁棒μ综合控制器保证了主动悬架系统的名义性能和鲁棒性;与基于名义模型设计的H∞控制器相比,闭环系统能获得更好的鲁棒性能.     

波状圆柱绕流减阻的实验研究

为了寻找一种减阻、减振而又不受流动方向限制的方法,提出了一种可降低绕流阻力的波状圆柱,并对波状圆柱的平均阻力系数以及表面压力分布进行了实验研究.实验在某低速风洞进行,工作段的横截面尺寸为0.6 m×0.6 m,湍流度小于0.2%.实验中的Re在2.0×104到5.0×104范围内.实验结果表明:3种不同倾斜度的波状圆柱平均阻力系数小于普通圆柱的平均阻力系数,最大减阻效果可达20%以上;流体在波状圆柱的最小横截面上分离得早,表面压力下降快;波状圆柱表面倾斜度是影响流场的重要参数,其取值大小直接影响波状圆柱的减阻效果.     

软件测试自动化的实施方案

文章论述了软件测试自动化的实施，从自动测试的好处、影响软件测试自动化实施的因素等几个方面出发，总结了软件自动化测试的实施方案。     

A novel fully-integrated miniature six-axis force/torque sensor

This paper presents a new designed miniature six DOF （degree of freedom） force/torque sensor. This sensor is fully integrated with a micro DSP （digital signal processor）, so all the signal conditioning, A/D, decoupling, digital-signals serial output are performed in the sensor. Some experimental results are presented to demonstrate the capability of the proposed design. Finally, a neural network was used for decoupling the interacting signals, compared with the conventional method using the inverse matrix, this new method is more accurate.     

基于上行信道盲估计的宽带码分多址用户检测器

针对宽带码分多址（CDMA）系统中同时存在多址干扰与码间串扰的情况进行研究,给出了适用于宽带CDMA系统的卷积模型,利用子空间技术及已知的扩频码信息,将适用于单用户的单输入多输出系统信道盲估计方法扩展到码发侈址系统中,实现了多用户上行信道的盲估计,利用有限码集特性,解决了上行信道盲估计中存在不确定复系数的问题,在此基础上,给出了最小均方误差多用户检测器的实现方案,计算机仿真实验证明,提出的方法可以同时克服多址干扰及码间串扰,是实现宽码分多址系统多用户检测的一个有效途径,同时该方法还可以推广到基站采用智能天线的系统中,实现对矢量信道冲激响应有的盲估计。     

Isolation, purification and characterization of secondary structure of antifreeze protein fromAmmopiptanthus mongolicus

Antifreeze protein (AFP) from Ammopiptanthus mongolicus leaves was isolated and purified with DEAE cellulose 52, Sephacryl 300, heat treatment and preparative isotachophoresis. The molecular weight of AFP was 50 ku by SDS-PAGE measurement. The average thermal hysteresis activity (THA) of AFP was 0.35℃ at 5 mg/mL using a differential scanning calorimeter (DSC). This AFP showed heated stability. From circular dichroism (CD) of AFP spectral data from 195—240 nm, a well-defined secondary structure of 11% a-helix, 34% antiparallel b-sheet and 55% random coil for the plant AFP was deduced.     

Preparation and optical properties of composite thin films with embedded InP nanoparticles

InP nanoparticles embedded in SiO₂ thin films were prepared by radio-frequency magnetron co-sputtering. We analyzed the structure and growth behavior of the composite films under different preparation conditions. X-ray diffraction and Raman spectroscopy analyses indicate that InP nanoparticles have a polycrystalline structure. The average size of InP nanoparticles is in the range of 3–10 nm. The broadening and red shift of the Raman peaks were observed, which can be interpreted by the phonon confinement model. Optical transmission spectra indicate that the optical absorption edges of the films can be modulated in the visible light range. The marked blue shift of the absorption edge with respect to that of bulk InP is explained by the quantum confinement effect. The theoretical values of the blue shift predicted by the effective mass approximation model are different from the experimental results for the InP-SiO₂ system. Analyses indicate that the exciton effective mass of the InP nanoparticles is not constant and is inverse relative to the particles radius, which may be the main reason that results in the discrepancy between the theoretical and the experimental result. We discussed the possible transition of the direct band gap to the indirect band gap for InP nanoparticles embedded in SiO₂ thin films.     

基于主题词权重和句子特征的自动文摘

为获得高质量的自动文摘,在组合词识别算法的基础上,充分考虑词的频率、词性、词的位置、词长等因素,构建了一个词语权重计算公式,该公式能使表达主题的词和短语具有较高的权重.对句子权重的计算,则考虑了句子的内容、位置以及线索词的作用和用户偏好等.摘要的生成充分考虑了候选文摘句的相似性,避免了冗余信息的加入.对摘要的评估进行了从句子粒度到词语粒度的改进,提出了一种基于词语粒度的准确率和召回率计算方法.实验证明,该算法生成的自动文摘有着较高的质量,平均准确率达到77.1%.     

基于PLC的工厂生产流水线控制系统的开发

PLC的特点是具有强大的控制能力、高精度、高可靠性,具有复杂的逻辑能力和运算能力,因此可充分满足对流水线的控制需求。在对玻璃生产流水线的控制需求进行分析的基础上,阐述了基于PLC的工厂生产流水线控制系统的开发过程。     

基于综合语义度量的本体映射方法

在分析现有本体映射技术的基础上,采用基于本体图结构和启发式规则的本体映射方法实现了本体间一对一映射,最后通过选取实验对象进行测试,证明了本映射机制的可行性.