基于模糊度测度和改进遗传算法的图像分割

为了利用模糊集理论进行图像分割,本文提出了一种模糊度测度函数,它衡量了背景模糊集和某一个二值图像的相似性:模糊度越小,这种相似程度越大;并且对模糊度的计算只需要进行简单的比较运算和加法运算,便于硬件实现。本文利用遗传算法求取最佳阈值,针对遗传算法的某些不足之处.我们利用精英策略和模拟退火的思想,对其做了一些修正。实验结果表明:相对于Shannon熵方法和模糊熵方法,本文方法取得了较好的分割结果,并且具有较强的抗噪声能力。     

宽带智能天线系统中的频率补偿技术

在无线通信中,智能天线系统在抑制窄带多径干扰方面具有得天独厚的优势,但是用于宽带无线通信系统中时,就需要采用频率补偿方法.重点介绍基于频谱分解、聚焦和插值算法的补偿技术,并对这3种频率补偿技术的性能进行比较,结果表明在应用补偿技术的系统中,系统性能有显著的改善,其中插值算法具有最优的性能.     

PERIODIC DYADIC GREEN''S FUNCTION FOR FIELD ANALYSIS IN EMC CHAMBER

Herein a novel Dyadic Green's Function (DGF) is presented to calculate the field in ElectroMagnetic Compatibility (EMC) chamber. Due to the difficulty of simulating the whole chamber environment, the analysis combines the DGF formulation and the FEM method, with the latter deals with the reflection from absorbers. With DGF formulation for infinite periodic array structures, this paper investigates electromagnetic field in chamber with truncated arrays. The reflection from the absorber serves as the virtual source contributing to the total field. Hence the whole chamber field calculation can be separated from the work of absorber model set-up. Practically the field homogeneity test and Normal Site Attenuation (NSA) test are carried out to evaluate the chamber performance. Based on the method in this paper, the simulation results agree well with the test, and predict successfully the victim frequency points of the chamber.     

Effect of Processing Temperature on the Morphology of Silicon Carbide Whiskers

Two kinds of SiC whiskers were annealed at temperatures similar to those for the processing of ceramic matrix composites. The morphology and structure of the as-received and postannealed whiskers were investigated by SEM, TEM, and XRD, and the influence of processing temperature on the mechanical properties of ceramic matrix composites was discussed.     

WATCHDOG在汽轮发电机组状态监测系统中的应用

本文介绍一种适合于汽轮发电机组状态监测系统的“看门狗”功能,它可以在很短时间内发现由于外界干扰而导致的计算机的锁死,并马上自动使计算机恢复正常运行。从而提高在线状态监测系统的可靠性。     

模块化蓝光光存储性能静态测试系统

蓝光光存储是信息存储领域发展的一个重要方向。测试系统是研究蓝光光存储材料的必备条件，为建立蓝光光存储研究平台，设计和搭建了一套模块化蓝光光存储性能静态测试系统。激光工作波长为406．7nm。系统采用调制解调技术降低系统噪声，提高测量粘度：采用光点移动模式降低对样品尺寸的要求；采用纳米平台提高记录点的反复定位性能。实验结果证明测试系统性能良好，可以满足蓝光光存储性能静态测试要求。     

Improved domino logic for high speed design

Techniques are introduced to improve the speed of domino logic. With an inverted clock scheme, a serial transistor is removed and capacitances at the output node are reduced in the new structures. HSPICE simulation shows that over 20% performance enhancement is achieved.     

单小波去噪方法在多小波去噪中的应用研究

单小波去噪方法中Visualshrink去噪法是渐进最优的。但将'Visualshrink单小波去噪方法用于多小波去噪,其优越性丧失,图象中存在严重的Gibbs效应,且去噪效果降低,对此,我们改进了单小波Visualshrink去噪方法的门限选取,提出了改进的Visualshrink多小波去噪方法(VMD)。同时,还给出了离散多小波变换的具体实现方法。实验结果证明,改进的多小波去噪方法与直接将Visualshrink方法用于多小波去噪相比,前者效果明显好于后者。     

纳米陶瓷的制备

纳米陶瓷材料可显著降低材料的烧结致密化程度,节约能源;并可改善陶瓷材料的性能,提高其使用可靠性。主要介绍了纳米陶瓷的制备方法,包括纳米陶瓷粉体的制备、成型和烧结。