一类带弱奇异核的偏积分微分方程的数值解

给出了数值求解一类偏微分方程的一种一阶全离散格式。x方向采用Galerkin谱方法,t方向用拉普拉斯的数值逆求解。该方法选择适当的n可以达到所需要的精度。     

浅谈新闻节目主持人的个性化

从新闻主持人的外观形象、语言风格和气质特点3个方面，论述了当前新闻节目主持人的个性化问题，分析了新闻节目主持人与新闻节目的关系及作用。     

Analyzing Nonstationary Random Response of a SDOF System under the Evolutionary Random Excitation by Wavelet Transform

For evolutionary random excitations, a general method of analyzing nonstationary random responses of systems was presented in this paper. Firstly, for the evolutionary random excitation model, the evolutionary power spectrum density function （EPSD） of a random excitation was given by wavelet transform. Based on the EPSD, the nonstationary responses of a SDOF system subjected to evolutionary random excitations were studied. The application and validity of presented method were illustrated by numerical examples. In numerical examples, the recently developed stochastic models for El Centro （1934） and Mexico City （1985） earthquakes which preserve the nonstationary evolutions of amplitude and frequency content of ground accelerations were used as excitations. The nonstationary random mean-square responses of a SDOF system under these two excitations were evaluated and compared with simulated results.     

基于3S的土地利用时空特征研究——重庆市北部新区为例

在3S（GIS，RS，GPS）技术的支持下，通过建立数学模型对城市土地利用时空特征进行研究，并以重庆市北部新城为试验区域，对该区域土地利用类型、土地利用程度、城市扩展等时空特征进行了动态分析，取得了良好的效果，为定性定量研究区域土地利用、土地覆盖的时空演变提供了一种新思路和新方法。     

一种基于导频的OFDM系统信道估计方法

提出一种使用矩形导频图案的OFDM信道估计方法。接收端首先在频率方向估计信道,然后在时间方向插值。该方法仅需累加和少量乘法运算就能估计出信道冲激响应,复杂度低,实时性高。在未编码16QAM-OFDM系统中,通过仿真将提出的方法与线性、cubic和MMSE插值法进行均方误差和误比特率的比较。结果表明该方法性能优于前两者,接近后者。     

采用小波域α稳定分布的图像去噪

基于统计模型的图像去噪的关键是统计模型的选取.α稳定分布能很好地表示具有严重拖尾的数据的统计分布.该文采用α稳定分布来对图像小波域系数进行建模,并采用贝叶斯估计来对无噪图像进行估计.通过将该算法与近来的一些方法进行比较,仿真结果表明该算法具有好的去噪效果.     

基于图像变换域的双重数字水印方法

基于变换域的双重数字水印方法,通过嵌入鲁棒水印和脆弱水印实现了图像内容版权保护和完整性认证的双重目的.其优点是利用小波变换,分块、适应性嵌入鲁棒水印,在图像的高频和低频中分别嵌入鲁棒水印,使鲁棒水印更加强壮;同时它利用离散余弦变换,在图像的高频部分嵌入脆弱水印,使脆弱水印在遭受攻击或篡改时更易被损坏.     

Analyzing and Designing Business Processes Management System Based on Transformation of Instantiated Ontology＇s State

The paper discusses efforts of finding a simple and transparent method to analyze business processes and developing its management system architecture. By introducing ontology and its state, the approach tried to find a unified representation and a flexible choreography of business processes. The main idea of the paper is the transformation of ontology＇s states, which are the most important scenarios of enterprises. The business activity composition, that is, case composition based on an AI technique, Case Based Reason （CBR）, which is to solve new problems by retrieving solutions to previous problems, and then store the modified solution. The main interest in CBR relies on that it allows a system to avoid past failures and exploit past successes.     

明代八股文对文人创作的背离

确立于明代的八股文,对明清文人和文学创作影响极大,它既带给文人荣华富贵的梦想,也给他们带来强烈的精神苦闷和焦虑。其程式化、格式化在某种程度上影响了文人独创性和个性的发挥,影响了他们文学创作的思维方式。后世才子背离八股文写作从而获得较大成就。     

数学的形态与教师的任务

数学有3种形态:原始形态、学术形态、教育形态.教师的主要任务在于把学术形态的数学转化成教育形态呈现给学生,给予学生一个“平易近人”的数学.要做好这一点,使数学生活化、立体化、简单化、结构化、美化是较为有效的做法.