一种二维离散子波变换的滤波器结构

子波变换具有良好的时间（空间）频率局部化性能，在图象子带编码中二维离散子波变换是一种接近理想的子带分析／综合子系统．本文提出一种利用一维离散子波变换实现二维有限长离散子波变换的方法，同时给出了二维离散子波正变换（DWT）和反变换（IDWT）的滤波器实现结构．实验结果表明新的方法具有良好的重构性，完全适用于图象压缩编码系统中的分析／综合子系统．     

振镜式在线激光打标扫描方案的设计

论述了振镜式激光打标扫描方案的设计和实现过程 ,通过对振镜扫描速度的补偿解决了由于生产线的运动而造成的打标字符倾斜问题 ,并且有效提高了打标的速度 ,实现了在不同速度生产线对不同材质进行打标     

基于Bessel插值的数字正交相干检波器镜频抑制

该文叙述了两种插值方法实现数字正交相干检波的基本原理,分析了信号流程,重点讨论和比较了两种方法的镜频抑制效果并做了相应仿真,理论分析和仿真结果对于数字正交相干检波的工程实现有一定参考价值。     

直接数字波形合成中的镜频干扰分析

该文针对数字波形合成信号中的镜频干扰问题展开讨论,着重分析了镜频的形成机理及分布特点,说明了采样率对镜频干扰的影响。在此基础上定量分析了产生镜频干扰的采样率条件,并通过实验结果验证。该分析结果为数字波形合成中的采样率选取提供了新的理论依据。     

A cost-effective method for detecting web site replicas on search engine databases

Identifying replicated sites is an important task for search engines. It can reduce data storage costs, improve query processing time and remove noise that might affect the quality of the final answers given to the user. This paper introduces a new approach to detect web sites that are likely to be replicas in a search engine database. Our method uses the websites’ structure and the content of their pages to identify possible replicas. As we show through experiments, such a combination improves the precision and reduces the overall costs related to the replica detection task. Our method achieves a quality improvement of 47.23% when compared to previously proposed approaches.     

Enhancing mirror adaptive random testing through dynamic partitioning

ContextAdaptive random testing (ART), originally proposed as an enhancement of random testing, is often criticized for the high computation overhead of many ART algorithms. Mirror ART (MART) is a novel approach that can be generally applied to improve the efficiency of various ART algorithms based on the combination of “divide-and-conquer” and “heuristic” strategies.ObjectiveThe computation overhead of the existing MART methods is actually on the same order of magnitude as that of the original ART algorithms. In this paper, we aim to further decrease the order of computation overhead for MART.MethodWe conjecture that the mirroring scheme in MART should be dynamic instead of static to deliver a higher efficiency. We thus propose a new approach, namely dynamic mirror ART (DMART), which incrementally partitions the input domain and adopts new mirror functions.ResultsOur simulations demonstrate that the new DMART approach delivers comparable failure-detection effectiveness as the original MART and ART algorithms while having much lower computation overhead. The experimental studies further show that the new approach also delivers a better and more reliable performance on programs with failure-unrelated parameters.ConclusionIn general, DMART is much more cost-effective than MART. Since its mirroring scheme is independent of concrete ART algorithms, DMART can be generally applied to improve the cost-effectiveness of various ART algorithms.     

远程数据库迁移技术研究

数据库迁移技术起源于分布式数据库, 在高带宽的网络环境下,该技术可大幅度减少分布式数据库的事务处理时间,提高系统的查询性能,增强系统的容灾能力。讨论数据库迁移系统实现中的一些关键技术。     

一种远程备份/恢复系统的设计和实现

设计并实现了一种远程备份/恢复容灾系统——DRC。该系统采用本地灾备网关作为中间介质,实现本地高速镜像;通过镜像远程设备到本地,实现远程数据备份;使用实时状态监控和系统重建技术完成系统的自动恢复,以达到容灾的目的。另外,该系统支持多种操作系统和数据库;远程备份和恢复工作采取用户控制和系统自动实现两种方式;该系统还提供了配置管理工具,便利远程管理。     

基于Mirror Driver的自适应屏幕录制算法

提出一种基于Mirror Driver的自适应屏幕录制算法MDAC,该算法运用Mirror Driver技术检测屏幕显示内容的变化,并通过检测该区域的更新频率,自适应地选择图像编码算法。实验结果表明,该算法能够在保证屏幕录像质量的情况下,大幅度降低CPU占用率和录制文件的大小。     

BSRF镜箱远程可视化控制实验平台的设计与实现

介绍了一种北京同步辐射装置(BSRF)镜箱远程可视化控制实验平台的设计与实现.该平台基于客户端/设备服务器结构,以模拟反射镜箱为控制对象,通过自行设计的简单文本通讯协议(SAMP)和镜子三维运动模型,实现了模拟镜箱的远程可视化控制.客户端合法性审核和访问时效等安全策略应用,保证了底层设备的安全访问.实验室测试结果表明,...