范式应用

从五个实例出发介绍了数据库设计的第一范式、第二范式、第三范式、BCNF范式和第四范式的定义及达到各种范式的要求.     

Preferential normal fuzzy subgroups

In this paper we consider the notion of normality on preferential fuzzy subgroups of a finite group G and define the associated concept of a normal pinned-flag. We discuss the preferential equality of quotients and products of normal preferential fuzzy subgroups. Further normalizers of fuzzy subgroups under preferential equality are briefly dealt with. Examples are given to illustrate the structure of preferential normal fuzzy subgroups and normal pinned-flags.     

Vibrotactile perception thresholds in four non-exposed populations of working age

The purpose of this study was to establish a basis for the use of a device for measuring vibrotactile perception thresholds for epidemiological purposes on a series of non-exposed populations. Vibrotactile perception thresholds (VPTs) were measured with a vibrometer in 218 men and 160 women belonging to two non-exposed male blue collar populations, one white-collar population and one age and gender stratified sample of the general population. VPTs were measured on the middle and the little finger of the dominant hand at 31.5 and 125 Hz. The VPTs were expressed in dB and the effect of a series of factors including the population, age, gender and digital temperature was assessed in a regression analysis weighted by the inverse variance of the measurements. Adjusted for age, no significant difference between the VPTs in the four male populations was observed. At frequency 125 Hz, the effect of age (0.3 dB per year) was more important than at frequency 31.5 Hz (0.2 dB per year). In the two female populations, the results were less stable than among males and the VPTs were higher than among males. However, the age-dependence was similar among males and females. The within-test variance is a valuable indicator of the quality of the VPT measurements. Weighting by its inverse improved the fit of the regression models. Normal values for VPTs in non-exposed populations were obtained, which were reproducible in four separate populations.     

三维表面的曲面描述与相似性判别

针对三维物体表面的描述和识别问题,从描述三维表面变化的基本参数-法向量出发,以法向量累积分布曲线NVCDC为不变量,对比较光滑的三维曲面,给出了一个描述形状的方法方法和相似性判别准则,并依法向量的方向角将三维空间分割成子空间,然后统计落入每个子空间的法向量个数,以得到法向量的分布,再将其排序后,即得到法向量累积分布曲线NVCDC,由于与不同的法向量累积分布曲线对应的三维曲面也是不同的,所以采用NVCDC之间的差异为相似性判别准则,对不同三维曲面进行了一对一的相似性判别,为检验该方法的效果,还对足底表面进行了实验,结果表明,该曲面描述方法与相似性判别则是有效的。     

对《一种比QUICKSORT更快的排序算法》一文的改进

本文根据正态分布函数的特性,将原文中用二次函数逼近的方法,改用sinx函数去逼近。利用该函数计算被排序数据的序号,可以大大提高排序的速度。     

数理逻辑中范式教学探讨

命题公式范式是命题逻辑中的一个重要内容,也是计算机学科中人工智能、软件工程等多门核心课程的重要数学基础。本文作者对此内容进行了深入的研究,在结合教学实践的基础上,提出了一个完整的教学案例。     

师范院校计算机人工智能双语教学的方案设计

双语教学作为一个新的教学模式在高校的教学中还处于探索、研究阶段。本文结合人工智能课程的双语教学实践,详细分析了师范院校双语教学的特点,提出了师范院校双语教学遵循的原则,最后设计出了人工智能双语教学的方案。     

白蚁虫害仿真预测系统中反规范化的应用

白蚁虫害仿真预测系统中所应用的数据库首先都是基于规范化原则设计的,但考虑到效率的问题,就按照数据仓库中的反规范化原则对数据库进行了改进.本文在简要介绍了数据库中反规范化的应用后,详细地举出了一个用反规范化设计的数据库来讨论如何通过反规范化进行数据库设计优化.     

GF（2^m）上自适应正规基乘法器的FPGA实现

本文从实际应用出发,研究了GF：2^m）上基于正规基的乘法运算的FPGA的实现.采用w-SMPOⅡ算法,FPGA实现了任意域长m上的任意字长w的乘法器.并给出了几个域上的乘法器的面积和速度的比较分析.     

关系模式规范化研究

介绍了第一、第二、第三、BCNF、第四、第五范式和域/关键字范式.     

基于单片机的工频相角源

介绍了用间接频率合成器(IS)数字波形发生器以及程控衰减器构成的工频相角源，它以单片机为控制核心，实现了频率、相角、幅值的数显及步进调整。     

Flash课程教学改革研究

本文从Flash教学实际出发,在分析了Flash传统教学方法的基础上,本文提出了Flash教学改革的新思路,针对所提出的问题,结合自身的教育实践经验,从教学内容、教学模式方法、师资队伍培养等多个方面,提出了Flash教学改革的几点构想。     

师范生多媒体课件制作和应用能力培养研究

多媒体技术具有交互性,在教育教学中广泛应用。教师制作多媒体课件,并应用于课堂教学。针对多媒体课件制作和应用的现状及存在的问题,培养师范生多媒体课件制作和应用能力。     

一种计算试卷中试题难度分布的有效方法

该文提出一种依据正态分布函数计算试卷中试题难度分布的方法，并将茯运用于智能组卷系统，计算机仿真结构表明了该方法的有效性。     

Normal vector and winding number in 2D digital images with their application for hole detection

Differentiating hole from component is an important issue in digital topology. In a recent paper, Lee, Poston, and Rosenfeld proposed a method to distinguish external and internal boundaries in 2D and 3D images relying on the property of normal vector and winding number. The method uses a smoothing function to replace digital lattice for calculating normal vector on image boundary. In this paper, we show that normal vector and winding number can be defined directly in 2D digital images and used for hole detection without resorting to any smoothing operation. We analyze first the discontinuity of Freeman codes of contour and prove its properties. We define then outward normal vector in 2D images and demonstrate also its discontinuity properties. The difficulty of counting the transition of normal vector in a given direction is analyzed and a solution is proposed. Based on the theoretic properties of edge code and normal vector, we propound the first algorithm to count the transitions of normal vector in a given direction, and consequently holes and external contours can be distinguished easily. We further define winding number directly in digital images, show its properties, and propose a second algorithm implementing the idea of winding number which is conceptually simpler and easier than the first one. A proof of correctness of our both algorithms is given and computation results are presented.     

在Windows下使用五笔字型输入法常见问题及解决方法

讨论了98王码WB9801五笔字型输入法软件在Windows环境下使用时应注意的问题、出现异常现象的解决方法及使用技巧。