HIFU中的运动控制装置设计

本文针对HIFU(High Intensity Focused Ultrasound)中的运动控制系统。采用了分布式多轴运动控制方案，设计了基于Atmegal28单片机芯片的运动控制装置的硬件和软件，并通过试验验证了该方案的有效性。     

线路绝缘子污秽状态在线监测的研究

阐述了绝缘子污闪机理及泄漏电流监测原理。介绍了符合广西气候特征的直流绝缘子在线监测的监测系统。试验表明,这种设计方案具有结构简单,操作方便,测量准确可靠的特点。     

关于 RSA 的模拟

基于Fp上多项式的性质，改进了曹珍富文中提出的模拟RSA型公钥密码体制，通过适当选取参数，解决了其中存在的密文扩展问题，讨论了改进后体制的安全性，并给出了一个RSA的新模拟，其密文无扩燕而且更接近于标准RSA的概念。     

一种新的个性化的图象分类方法

图象分类系统的建立是信息检索以及模式识别中一个重要部分，其中，特征选择问题，即确定描述图象的特征参数是需要解决的关键问题，基于和图象检索技术的研究，近来得到了广泛的关注，由图象特征向量维数过高而引起的图象检索困难是基于内容的图象检索技术研究所面临的一个挑战，因此需要寻找一个有效降维技术，为解决此问题，设计了一个新的图象分类标准模型，通过寻找不同的特征组合来作为分类标准，进而提出了一种算法，用于实现此模型，实验结果显示，该模型能实现图象特征向量降维，并且算法能够极大地降低计算所花费的时间，同时，多种不同分类标准的引入，使得本方法能与信息检索技术进行有效的结合，为个性化信息检索提供一种实现思路。     

中国古典诗词研究中的“悬案”刍议

对中国古典诗词的研究,经常会因为对作品可以作不同的理解而造成研究者观点上的分歧,从而产生诸多诗词研究中的“悬案”。这种学术观点上的分歧固然没有标准答案,但只要掌握了正确的研究方法去分析辨别,不同观点间的优劣还是可以进行比较的。     

H_∞控制的状态空间方法与H_∞状态反馈控制

本文给出了H∞控制问题的状态空间及其存在条件，引出了H∞控制问题的状态空间解法，对这些解法进行了比较概括的陈述，并对H∞状态反馈控制及其最优解作了一些探讨。     

Spectroscopic ellipsometry of anisotropic materials: application to the optical constants of HgI2

A variable angle-of-incidence spectroscopic fixed-polarizer, rotating-polarizer, fixed-analyzer ellipsometer (PRPSE) across a spectral range from 300 to 800 nm is used to determine the optical properties of anisotropic uniaxial tetragonal red mercuric iodide (HgI(2)). For the first time, to our knowledge, the bulk crystal HgI(2) surface measured by ellipsometry was not subjected to potassium iodide cutting or etching. Measurements were made at an air-HgI(2) interface with the optic axis parallel to the sample surface. To determine the optical constants, we varied both the angle of incidence and the azimuth of the optic axis with the plane of incidence. The detailed formulas needed for reliable procedures for analyzing the data are presented. The ordinary and extraordinary complex indices of refraction, (n(o) - ik(o)) and (n(e) - ik(e)), respectively, are determined. Good agreement between PRPSE and the prism technique for the refractive index is observed. The surface aging effects of the ellipsometric parameters of HgI(2), during 30 h of exposure to air, were detected by PRPSE.     

Weighted support vector machine for quality estimation in polymerization processes

In this paper, a modified version of the Support Vector Machine (SVM) is proposed as an empirical model for polymerization processes modeling. Usually the exact principle models of polymerization processes are seldom known; therefore, the relations between input and output variables have to be estimated by using an empirical inference model. They can be used in process monitoring, optimization and quality control. The Support Vector Machine is a good tool for modeling polymerization process because it can handle highly nonlinear systems successfully. The proposed method is derived by modifying the risk function of the standard Support Vector Machine by using the concept of Locally Weighted Regression. Based on the smoothness concept, it can handle the correlations among many process variables and nonlinearities more effectively. Case studies show that the proposed method exhibits superior performance as compared with the standard SVR, which is itself superior to the traditional statistical learning machine in the case of high dimensional, sparse and nonlinear data.     

Star Cube--一种高效的数据立方体实现方法

一个具有n个维的数据立方体有2^n个视图,视图越多,用于维护数据立方体的时间也就越长。通过将维分成划分维和非划分维,数据立方体可以转换成star cube．stal cube由一个综合表和那些仅包含划分维的视图组成。star cube使用前缀共享和元组共享技术不仅减少了所需的存储空间,还大大减少了计算和维护时间。在把一个分片限制在一个I/O单位的条件下,star cube的查询响应时间与数据立方体基本相同。实验结果也表明,star cube是一种在时空两方面均有效的数据立方体实现技术。     

Morphology of the Cu‐rich Phase in Cu‐Pb Hypermonotectic Alloys under an Intense Magnetic Field

The solidification structure of a Cu‐80wt%Pb hypermonotectic alloy was investigated under four different experimental conditions. The results show that the spherical Cu‐rich phase in the matrix has three kinds of morphology, that is the larger “net‐shell type” and the smaller “egg‐type” or “eye‐type”. The cooling rate of the samples has a great effect on both macrostructure and microstructure. As the cooling rate becomes slow, the Cu‐rich phase changes from fine spheres to larger floating spheres and finally to coarse dendrites, and the thickness of the Cu‐shell and the net of Cu‐Pb phase in the Cu‐rich spheres become coarser. A magnetic field of 12 T has a remarkable effect: it restrains the gravity segregation of the Cu‐Pb alloy by preventing the floating of the larger Cu‐rich droplets and the sedimentation of the Pb‐matrix. Thus, the Cu‐Pb monotectic alloy exhibits a macrostructure and microstructure which are similar to those obtained at relatively fast cooling rates. The 12T magnetic field is supposed to restrain the collection of solute Cu extracted from the liquid Pb phase and the diffusion of solute Cu to the Cu‐shell in the centre of larger Cu‐rich droplets.