基于OWPB和LS-SVM的电路板故障诊断系统

针对雷达电路板检修困难的问题,提出了基于最优小波包基和最小二乘支持向量机相结合的雷达电路板故障诊断方法。利用小波变换对采样数据进行去噪处理,通过小波包分解选择最优小波包基提取熵值作为故障特征向量,并作为基于最小二乘支持向量机的雷达故障诊断模型的输入向量,经诊断模型输出后,完成雷达电路板故障诊断。基于此方法设计了雷达电路板故障诊断系统,提高了雷达故障诊断的正确性和效率。     

Flocking based distributed self-deployment algorithms in mobile sensor networks

In this paper, we address a novel deployment problem in isotropic mobile sensor networks. Sensors are to be relocated uniformly in a region of interest (ROI) centered at a target of interest (TOI) which could be stationary or mobile. With the assumption that relative direction of a sensor to the TOI can be recognized or inferred by devices equipped in the sensor, distributed control algorithms based on first-order and second-order dynamic models are proposed for both stationary and mobile TOI situations. The Lyapunov stabilities and coverage guarantee are provided. To further improve the deployment such as coverage holes inside the network and uniformity of the deployment, four assisted rules are also proposed. Then algorithms proposed for the situation of a stationary TOI are extended to anisotropic sensor networks. Simulations demonstrate the effective performances of the proposed algorithms.     

A new liquid crystal lens with axis-tunability via three sector electrodes

A novel liquid crystal (LC) lens with an on-line tunability on focus length and optical axis is proposed in this study. The designed lens has a LC layer sandwiched by two ITO glasses, one of which is patterned with three sector electrodes. With varied sets of pre-designed voltages applied to these three electrodes, the LC lens can not only render focusing effects but also tunability on the optical axis of the lens to an arbitrary axis. A vector-form equation is developed to predict the direction of axis tuning. Simulations are next conducted to predict dynamics of the LCs in the lens and also the focusing and axis-tuning properties of the lens. Important sizes and materials and fabrication process of the lens are determined and optimized based on simulation results. The designed LC lens is fabricated, and then experiments are conducted to demonstrate the performance of the designed LC lens on axis tuning. It shows that the focusing axis of the LC lens can be effectively changed by pre-calculated combinations of three voltages. It is also shown that the average movement of the focal point per applied voltage reaches 4.778?μm/V.     

校园卡管理信息系统的设计与实现

本文分析了校园卡管理信息系统的功能需求,对系统功能模块设计、数据库的设计与实现以及后台信息管理模块的设计与实现,进行了详细的介绍。     

偏最小二乘判别分析结合F-score用于蛋白质组学质谱数据的特征筛选(英文)

提出了一种基于偏最小二乘判别分析和F-score的特征筛选方法,并将其用于蛋白质组学质谱数据分析。该方法主要包含3个步骤:(1)用LIMPIC算法对原始数据进行预处理;(2)计算每个变量的F-score值并将所有变量按F-score值降底的顺序排列;(3)采用偏最小二乘判别分析交互检验按前向选择法选择最佳变量子集。用本方法对一组结肠癌数据进行分析,最终从原始的16331个质荷比变量中选择了8个特征质荷比作为潜在的生物标记物。用所选择的特征对独立测试集的样本进行判别,其灵敏度和特异性分别达到了95.24%和100%。结果表明,所提出的方法可用于蛋白质组学质谱数据的特征筛选及样本分类。     

基于变量纯度的波长选择方法在近红外光谱分析中的应用

提出了一种基于光谱纯度值的变量选择方法。对光谱中各变量计算其纯度值后,按降序将相应变量排列,采用PLS交互检验按前向选择法选择最佳变量子集。用本方法对3组分混合物体系及烟草样品的近红外光谱进行变量选择,并与全谱变量建模的结果进行了比较。结果表明本实验给出的波长变量优选方法是一种比较有效和实用的变量筛选方法,通过变量筛选,可极大地减少光谱信息重叠,从而提高定量校正模型的预测精度和建模效率。     

基于可拓理论的网络安全评估研究

针对目前网络安全评估算法存在的不足,提出了一种基于可拓模糊层次分析的安全评估算法。该算法在模糊层次分析法的基础上,结合可拓理论,将调查问卷表收集到的指标值映射到可拓区间中,通过相对隶属度的计算,构建了新的判决矩阵,利用模糊层次分析法计算各指标的综合权重。通过对相对隶属度的加权排序,得到网络安全评估值。通过实例分析,说明该方法能综合考虑专家打分的权威性和调查问卷的普遍性,提高了网络安全评估的准确性和有效性。     

PEG分子量对PET—PEG共聚酯结晶性能的影响

通过ＰＥＴ和ＰＥＧ共缩聚，合成了ＰＥＴ—ＰＥＧ共聚酯，采用ＤＳＣ、等温结晶仪、Ｘ衍射分析仪和电子扫描电镜研究了ＰＥＧ分子量对该共聚酯结晶性能的影响。结果表明，在ＰＥＴ分子结构中引入ＰＥＧ链段，能有效提高结晶速度，共聚酯结晶结构与ＰＥＴ类似，但ＰＥＧ不进入晶格中，只起诱导结晶的作用。当ＰＥＧ分子量为４０００时，冷结晶温度Ｔｃｃ降得最低，但热结晶温度Ｔｃ反而比纯ＰＥＴ有所增加，１１０℃结晶速度ｔ１２＝１ｍｉｎ，而纯ＰＥＴ需１２ｍｉｎ。     

Ni implantation-induced enhancement of the crystallisation of amorphous Si

We report on the effect of Ni implantation on the crystallisation process of amorphous Si formed by ion implantation during excimer laser annealing. Scanning transmission electron microscopy and X-ray photoemission spectroscopy results show that NiSi₂ precipitates are formed in the Si–Ni-implanted samples. It is shown that the Ni implantation results in the enhanced crystallisation of amorphous Si during laser annealing. The Si–Ni-implanted samples become epitaxial to the Si substrate at 600 mJ/cm², while the Si-implanted samples produce epitaxial relationship at 800 mJ/cm². Possible mechanisms by which implanted Ni atoms play a role are given to describe the enhanced crystallisation process of amorphous Si.     

基于Internet的空分设备远程监视与故障诊断专家系统的研究

简介了远程监视与故障诊断专家系统在国内空分设备中应用的实际意义，着重分析了大型空分设备远程监视与故障诊断专家系统中远程监视模块和故障诊断模块的开发。