A Divide-and-Conquer Algorithm for Irregular Redistribution in Parallelizing Compilers

In order to achieve higher load balancing, it is necessary to solve irregular block redistribution problems, which are different from regular block-cyclic redistribution. High Performance Fortran version 2 (HPF-2) provides irregular distribution functionalities, such as GEN_BLOCK and INDIRECT. This paper is devoted to develop an efficient algorithm that attempts to obtain near optimal scheduling while satisfying the conditions of minimal message size of total steps and the minimal number of steps for irregular array redistribution. The algorithm intends to decrease the computation costs by dividing the whole block into sub-blocks and solving the sub-problems accordingly, and then merging them together to get final results. Simulation results show that our algorithm has comparable performance with a relocation algorithm developed previously (H. Yook and M. Park. Proceedings of the IASTED International Conference Parallel and Distributed Computingand Systems, Nov. 3–6, MIT, Boston, USA, 1999).     

数据挖掘的并行策略研究

文章对数据挖掘算法的并行策略进行了分类,分类技术主要集中在分割训练数据以及在每一个阶段的最后从处理器中抽取属性。这种方法在关联规则和决策树中得到了广泛的研究。在策略应用中,以DD算法为例进行了说明。在文章的最后,展望了并行数据挖掘的发展方向。     

A Compressed Diagonals Remapping Technique for Dynamic Data Redistribution on Banded Sparse Matrix

In many scientific applications, dynamic data redistribution is used to enhance algorithm performance and achieve data locality in parallel programs on distributed memory multi-computers. In this paper, we present a new method, Compressed Diagonals Remapping (CDR) technique aims to the efficiency of runtime data redistribution on banded sparse matrices. The main idea of the proposed technique is first to compress the source matrix into a Compressed Diagonal Matrix (CDM) form. Based on the compressed diagonal matrix, a one-dimensional local and global index transformation method can be applied to carry out data redistribution on the compressed diagonal matrix. This process is identical to redistribute data in the two-dimensional banded sparse matrix. The CDR technique uses an efficient one-dimensional indexing scheme to perform data redistribution on banded sparse matrix. A significant improvement of this approach is that a processor does not need to determine the complicated sending or receiving data sets for dynamic data redistribution. The indexing cost is reduced significantly. The second advantage of the present techniques is the achievement of optimal packing/unpacking stages consequent upon the consecutive attribute of column elements in a compressed diagonal matrix. Another contribution of our methods is the ability to handle sparse matrix redistribution under two disjoint processor grids in the source and destination phases. A theoretical model to analyze the performance of the proposed technique is also presented in this paper. To evaluate the performance of our methods, we have implemented the present techniques on an IBM SP2 parallel machine along with the v2m algorithm and a dense redistribution strategy. The experimental results show that our technique provides significant improvement for runtime data redistribution of banded sparse matrices in most test samples.     

Dynamic Program Analysis Tools in GCC and CLANG Compilers

Programming and Computer Software - Ever increasing software security requirements, the growing size of software projects, and the desire to reduce the time of software development and release...     

Needs Assessment in Data Communications Networking

Design of an effective communications network must include a thorough assessment of needs. This communications planning methodology proceeds with identification of viable alternatives for communications delivery, ultimately guiding hardware and software product selection. Planning must continue through pilot testing, training, and resource optimization.     

基于Web楼宇自动化系统中的数据采集和数据通信

介绍了基于Web的楼宇自动化系统的功能及设计目标,并提出了系统中的数据采集和数据通信的具体设计方案和实现方法。     

优化索引XML数据研究

介绍了文档树中嵌入编码机制的思想和扩展编码方法,提出了采用改进的扩展编码方式来对XML文档进行编码,并使用改进的B 树构造算法构建索引树,以期提高存储空间利用率并减少B 树节点分裂次数;最后,在理论和实验的基础上分析了数据查询的执行效率。     

优化动态二进制翻译器DigitalBridge

讨论动态二进制翻译器DigitalBridge的动态优化设计与实现,给出了基于edge profile的热路径选择算法FHFS,在热路径上实施了基于模式匹配的指令组合优化翻译和标志位延迟计算的优化。实验结果表明,优化后动态翻译的性能平均提高40%。     

基于Excel XP优化实验数据

该文通过介绍用Excel XP优化处理物理实验数据的过程,说明Excel XP在处理数据中的使用规范,并体验它在处理实验数据中的优越性。     

Data Retention and Privacy in Electronic Communications

The retention of communication data by network providers, often mandated by legislation, raises social and technical security concerns. A generic model combining technical, procedural, and legal controls can help secure retained data and minimize privacy threats against users.     

基于SPI的数据输出优化分析

在研究现有LED大屏幕显示数据输出电路的基础上,提出基于硬件电路挖潜改造,提高输出速度的实现方法.给出该方法的实现过程,并对在使用同一信号源的前提下,读数据信号及屏幕显示等控制信号衔接配合的工作过程进行了探讨.     

《数据通信》双语教学的实践探讨

双语教学作为新兴的教学形式,有许多值得讨论和有待于探索的问题.在开展<数据通信>课程的双语教学实践过程中,通过在教材上采用英文原版教材,在课堂上运用英语口语交流,在实践中结合C++编写网络应用程序和利用工具软件分析数据包等教学手段,使双语教学收到较好的教学效果.     

Data Hiding in Audio Using Random Orthogonal Matrices

ABSTRACT

In this paper, speech scrambling is done to secure the data and at the same time covert information is embedded in scrambled speech that can be transmitted through communication channel. The technique performs encryption by scrambling the spectral components of speech using random orthogonal matrices. At the receiver end, hidden message and original speech are recovered by decoding and decrypting the scrambled signal, respectively. Performance of technique is evaluated in clean and noisy channel environments.     

基于数据仓库的ETL过程优化

提出一种优化ETL整体过程的方法,包括：其一,针对现有ETL过程的局限性提出一个优化其整体流程的框架EICLF（Extracting/Integrating/Cleaning/Loading/Feedback）流程;其二,对现有相似重复记录的识别算法进行改进;其三,根据清理后得到的干净数据对源数据进行反馈处理。     

Optimizing Stepwise Animation in Dynamic Set Diagrams

A set diagram represents the membership relation among data elements. It is often visualized as secondary information on top of primary information, such as the spatial positions of elements on maps and charts. Visualizing the temporal evolution of such set diagrams as well as their primary features is quite important; however, conventional approaches have only focused on the temporal behavior of the primary features and do not provide an effective means to highlight notable transitions within the set relationships. This paper presents an approach for generating a stepwise animation between set diagrams by decomposing the entire transition into atomic changes associated with individual data elements. The key idea behind our approach is to optimize the ordering of the atomic changes such that the synthesized animation minimizes unwanted set occlusions by considering their depth ordering and reduces the gaze shift between two consecutive stepwise changes. Experimental results and a user study demonstrate that the proposed approach effectively facilitates the visual identification of the detailed transitions inherent in dynamic set diagrams.     

基于多维数据库的CUBE优化算法

多维CUBE计算在多维分析和处理中非常重要,本文针对数组CUBE提出了划分的方法,通过一次扫描基本方体计算不完全数组方体的所有分组。实验数据表明该算法能充分利用内存空间、减少I/O次数,具有较高的计算效率。     

基于多维数据库的CUBE优化算法

多维CUBE计算在多维分析和处理中非常重要，本文针对数组CUBE提出了划分的方法，通过一次扫描基本方体计算不完全数组方体的所有分组．实验数据表明该算法能充分利用内存空间、减少I／O次数，具有较高的计算效率：     

基于决策树的数据挖掘算法优化研究

决策树模型是数据挖掘中最常用的一种方法,具有较好的分类预测能力,并能方便提取决策规则。基于相似性原理,以测试属性和决策属性的相似度作为启发规则构建决策树。提出了一种新的决策树生成算法。并在高校教师综合考评系统中采用了这种新算法,实验结果表明这种新的决策树生成算法预测精度较高,计算也比较简便。