一次同余方程组的一种矩阵解法

同余方程组是数论中一个极为有用的课题。文中考虑的是具有一个未知数而具有不同的模的一次同余方程组。一般可以用中国剩余定理或者递推算法等方法给出一次同余方程组的解法。利用矩阵的初等变换和矩阵的Sm ith标准形给出了求解一次同余方程组的一种矩阵解法。     

测绘小软件集锦平台的设计与实现

随着测绘工作的广泛开展,诞生了许多为解决测绘工程实际问题而编制的小型测绘软件,小软件种类繁多、使用方法各异,由此给实际的使用、传输和管理等带来诸多不便。针对此问题,作者设计了测绘小软件集锦平台,并利用C#2008编程予以实现,使各个独立的软件及在大型软件下二次开发的软件新功能能够通过该平台方便地加载及集中使用,不但方便了使用者,也解决了大量小软件的管理、传输等问题。     

双循环半群上的群同余

为探讨双循环半群上的同态核,从双循环半群上的同余关系出发,讨论双循环半群关于这类同余的交做成的商群,刻画了这种商群的具体元素,给出双循环半群到整数加法半群的同态映射.结果证明双循环半群上的同态核是最小群同余,且这类特殊同余的交也是最小群同余.     

A note on the expressibility problem for modal logics and star-free regular expressions

The purpose of this note is to (i) raise attention for an interesting type of decision problem for logics, known under different names such as the expressibility problem and the uniform clone membership problem, (ii) disseminate a remarkable and powerful negative result of M.F. Ra?ǎ from the 1980s that seems to have escaped attention of many researchers, and (iii) show, with the help of Ra?ǎ's theorem, that the problem is undecidable for star-free regular expressions.In Section 1 we introduce the expressibility problem, taking Boolean formulas as an example. In Section 2, we present, and improve upon, Ra?ǎ's theorem for transitive modal logics. In Section 3, we derive, as a consequence of Ra?ǎ's theorem, the undecidability of the expressibility problem for star-free regular expressions. Finally, we conclude in Section 4 with some open questions.     

Age-related differences in emotion recognition ability: A cross-sectional study.

Experimental studies indicate that recognition of emotions, particularly negative emotions, decreases with age. However, there is no consensus at which age the decrease in emotion recognition begins, how selective this is to negative emotions, and whether this applies to both facial and vocal expression. In the current cross-sectional study, 607 participants ranging in age from 18 to 84 years (mean age = 32.6 ± 14.9 years) were asked to recognize emotions expressed either facially or vocally. In general, older participants were found to be less accurate at recognizing emotions, with the most distinctive age difference pertaining to a certain group of negative emotions. Both modalities revealed an age-related decline in the recognition of sadness and—to a lesser degree—anger, starting at about 30 years of age. Although age-related differences in the recognition of expression of emotion were not mediated by personality traits, 2 of the Big 5 traits, openness and conscientiousness, made an independent contribution to emotion-recognition performance. Implications of age-related differences in facial and vocal emotion expression and early onset of the selective decrease in emotion recognition are discussed in terms of previous findings and relevant theoretical models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

关于费马数的若干性质

根据费马数的定义探究它的一些结论,借助中国剩余定理,得出费马数的若干性质.     

一种联机手写算术表达式识别系统

该文介绍了一个完整的联机手写算术表达式识别系统。在笔划分组与符号识别方面,采用预处理结合搜索的方法优化置信度函数;在结构分析方面,提出了一套全新的基于符号分级的算法,并利用三叉树这种数据结构存储识别结果。实验表明,对于书写较为整齐的算术表达式,此系统能够对较复杂的结构予以正确率较高的分析与识别。     

基于正则表达式的测试数据自动生成技术

软件测试是提高软件可靠性、保证软件质量的重要手段。数据自动生成是测试自动化的重要组成部分。提出一种基于正则表达式的测试数据自动生成技术,生成的数据应该具有随机性、可控制、可定义、有意义、无错误等特性,特别是对大字段／专有类型等特殊类型的支持,可以解决目前测试数据自动生成存在的问题,具有良好的扩展性。     

基于WWW远程教育的数学解决方案

Internet已经进入超媒体时代,但是要在HTML的网页中显示数学公式是非常困难的。该文总结了在网页中数学公式的几种表示方法,并给出了一种全新的网页数学解决方案。