通用数据库集群服务器

基于集群技术构建的数据库集群服务器的研究是一个新热点,有许多不同的构造方法。文中在介绍了数据集群服务器概念和基本构造方法的基础上,设计了一种可以提供通用编程接口的体系结构,并分析了其工作原理和实现技术,同时也探讨了需要解决的数据存储、数据运算和事务处理问题。     

流处理数据获取系统中的通用显示模块实现

为了解决不同的数据获取系统中数据显示模块无法通用的问题,减小实现数据显示模块的工作量,本文设计和实现了一种应用于流处理数据获取系统的通用数据显示模块。这种数据显示模块分为显示数据生成节点和数据显示节点两部分。这两种节点作为系统定义的标准流处理节点,与系统中的其他节点采用相同的数据格式和数据接口定义,并可与相同数据域内的其他流处理节点任意连接,仅仅通过不同的工作参数表征其所在数据域的属性差异。通过对于显示数据产生和数据显示方式的抽象,在数据生成节点中采用统一的模型完成从输入数据流抽取和统计待显示信息的功能,在数据显示节点中根据数据的内禀维度提供了多种可视化模式供不同的数据信息显示使用。通过在系统中接入和配置上述两种节点可以实现数据显示模块的通用。这样的通用数据显示模块已经在海洋地震勘探和高能物理实验的数据获取系统中得到了应用。     

基于．NET的通用数据访问框架研究

本文提出一种采用XML格式配置DBMS信息的通用数据访问构造块框架，并对其重构。实现了基于.NET的通用数据访问构造块。     

通用数据转换平台研究与实现

针对数据集成中各种数据异构问题而产生的数据转换需求,提出了基于面向图编程的数据转换过程模型,设计并实现了一个基于Java和SWT技术的通用数据转换平台。同时也对系统的体系结构和具体实现如转换节点设计和数据转换引擎等关键部分进行了论述。     

数据融合仿真系统通用架构及关键技术研究

在构建数据融合仿真系统通用架构的基础上,介绍了系统主要功能和仿真流程;研究了数据融合模块设计、效能评估指标体系、效能评估数学模型等仿真系统实现的关键技术,从数据融合算法设计及系统软件开发两个方面,提出了数据融合仿真系统通用架构开发实现的基本思路和方法.该系统不但可用来研究评价不同数据融合模型、算法的性能,而且可用来评估数据融合系统的整体性能,对实际系统实现也有相当的借鉴作用.     

基于ASP技术的通用动态查询系统的设计与实现

B/S模式的系统受到越来越多的应用,其最广泛的应用是数据查询。随着数据量的增大,方便的通用数据动态查询系统将受到越来越多的重视。该文对用ASP实现这种通用动态查询系统进行了研究。     

基于图形处理器的通用计算模式*

针对GPU图形处理的特点,分析其应用于通用计算的并行处理机制和数据映射,提出了一种GPU通用计算模式的映射机制和一般性设计方法,并针对GPU的吞吐量、数据流处理能力和基本数学运算能力等进行性能测试,为GPU通用计算的算法设计、实现和性能优化提供参考依据。     

XML签名在高校人事管理系统中的应用

XML逐渐成为网络交换的通用语言,同时XML数据安全问题也引起了重视.本文通过分析XML签名的语法和过程,并结合.NET平台介绍了其在高校人事管理系统中实现的方法,实现教师信息传递的不可篡改性和完整性.     

基于GPRS远程自动雨量监测系统

设计了新型通用分组无线业务(GPRS)远程自动雨量监测系统，其借助成熟的GPRS无线数据通信技术，结合Internet构建了基于B/S架构的数据服务中心，通过数据库编程实现雨量站点远程管理和信息查询，开发了雨量信息查询站点，实现在Web上动态显示实时雨量分布图。该系统也为其他数据采集与监测系统提供了一种通用、理想的信息采集处理模型。     

一种通用数据转换工具的设计

文章简述了解决异构数据库数据转换的几种常用方法,并详细阐述了一种通用异构数据库数据转换工具的设计思路和实现方法。其对管理信息系统的开发和实施都有较高的使用价值。     

Transit smart card data mining for passenger origin information extraction

The automated fare collection(AFC) system,also known as the transit smart card(SC) system,has gained more and more popularity among transit agencies worldwide.Compared with the conventional manual fare collection system,an AFC system has its inherent advantages in low labor cost and high efficiency for fare collection and transaction data archival.Although it is possible to collect highly valuable data from transit SC transactions,substantial efforts and methodologies are needed for extracting such data because most AFC systems are not initially designed for data collection.This is true especially for the Beijing AFC system,where a passenger’s boarding stop(origin) on a flat-rate bus is not recorded on the check-in scan.To extract passengers’ origin data from recorded SC transaction information,a Markov chain based Bayesian decision tree algorithm is developed in this study.Using the time invariance property of the Markov chain,the algorithm is further optimized and simplified to have a linear computational complexity.This algorithm is verified with transit vehicles equipped with global positioning system(GPS) data loggers.Our verification results demonstrated that the proposed algorithm is effective in extracting transit passengers’ origin information from SC transactions with a relatively high accuracy.Such transit origin data are highly valuable for transit system planning and route optimization.     

An application system for automation of constant-time radio frequency electron paramagnetic resonance imaging

A Windows based application system for data collection, Fourier reconstruction and analysis of pure phase encoded constant-time radio frequency electron paramagnetic resonance (EPR) images, is described. The graphical user interface (GUI) of the system was written in MATLAB version 5.0, using its built-in GUI utilities. Design considerations of the application system included speed, flexibility and user-friendly data display and analysis. To maximize the speed of image data collection, MATLAB's built-in C interface system, MEX was not used for data collection. Instead, MATLAB programs call the C programs from the DOS prompt directly, based on the data collection parameters entered through the GUI. Computational procedures included various digital signal-processing steps such as filtering, interpolation etc. for the Fourier reconstruction of 2D, and 3D EPR images from the pure phase encoded data. Examples of 2D images illustrating the performance of the system are presented. Although the application system has been developed for the specific purpose of EPR imaging, it can easily be adapted to other areas such as magnetic resonance microscopy as well.     

设计模式和泛型技术在系统重构中的应用研究

重构是在不改变代码外在行为的前提下,对代码做出修改,以改进程序内部结构的过程.设计模式是对被用来在特定场景下解决一般设计问题的类和相互通信的对象的描述.泛型编程专注于将型别抽象化,形成功能需求方面的一个精细集合,并利用这些需求来实现算法.以一个应用系统的数据采集子系统的系统重构为例,将设计模式应用于系统重构中设计阶段,将泛型技术应用于系统重构实现阶段;讨论设计模式技术和泛型技术的结合对系统重构的作用与意义.     

Feature Competitive Algorithm for Dimension Reduction of the Self-Organizing Map Input Space

The self-organizing map (SOM) can classify documents by learning about their interrelationships from its input data. The dimensionality of the SOM input data space based on a document collection is generally high. As the computational complexity of the SOM increases in proportion to the dimension of its input space, high dimensionality not only lowers the efficiency of the initial learning process but also lowers the efficiencies of the subsequent retrieval and the relearning process whenever the input data is updated. A new method called feature competitive algorithm (FCA) is proposed to overcome this problem. The FCA can capture the most significant features that characterize the underlying interrelationships of the entities in the input space to form a dimensionally reduced input space without excessively losing of essential information about the interrelationships. The proposed method was applied to a document collection, consisting of 97 UNIX command manual pages, to test its feasibility and effectiveness. The test results are encouraging. Further discussions on several crucial issues about the FCA are also presented.     

The design and implementation of a road safety relational database

Road safety can be measured by the rate of road traffic accidents that occur periodically. In developing countries, one major problem confronting researchers in the area of road safety is that the sources of data collection are not centrally controlled. The proliferation of the sources of data collection leads to data incompatibility, incorrectness, inconsistency and redundancy. These, in turn, lead to inaccurate and conflicting statistics generated and published by different research groups. In this paper, a relational database to support road safety system and a technique for its implementation are presented. It is shown how the database can be processed and accurate statistics about road safety generated and analysed to support planning, decision making and control of operations by the authorities involved in road safety.     

基于GPS探测车的道路交通状态估计技术*

应用车载GPS探测车的运行数据来估计道路交通状态是目前交通检测领域的新技术.从该技术基本概念出发,重点对其中的数据采集和交通参数估计问题进行了探讨.结合英国浮动车数据系统(FVD)数据采集的优化模式及目前探测车最小覆盖率的研究,讨论了数据采集的效率与样本大小的问题.分析了目前典型的GPS探测车交通参数估计模型,如多元回归、神经网络、模糊推理及速度积分等模型.对该技术的进一步发展及在我国的应用前景进行了分析和展望.     

可定制数据采集技术的研究和实现

总结传统数据采集软件的设计方法和存在的弊端,分析研究不同数据采集任务的异同,提出可定制化的数据采集技术,并对页面设计、模型配置、页面生成、库表建立等进行设计和实现,改变传统的数据采集软件研制模式,提高数据采集工作效率。     

Quality of manual data collection in Java software: an empirical investigation

Data collection, both automatic and manual, lies at the heart of all empirical studies. The quality of data collected from software informs decisions on maintenance, testing and wider issues such as the need for system re-engineering. While of the two types stated, automatic data collection is preferable, there are numerous occasions when manual data collection is unavoidable. Yet, very little evidence exists to assess the error-proneness of the latter. Herein, we investigate the extent to which manual data collection for Java software compared with its automatic counterpart for the same data. We investigate three hypotheses relating to the difference between automated and manual data collection. Five Java systems were used to support our investigation. Results showed that, as expected, manual data collection was error-prone, but nowhere near the extent we had initially envisaged. Key indicators of mistakes in manual data collection were found to be poor developer coding style, poor adherence to sound OO coding principles, and the existence of relatively large classes in some systems. Some interesting results were found relating to the collection of public class features and the types of error made during manual data collection. The study thus offers an insight into some of the typical problems associated with collecting data manually; more significantly, it highlights the problems that poorly written systems have on the quality of visually extracted data.     

自动并行库中基于存储转发机制的通信优化

文中工作是在曙光２０００上的ＰＶＭ环境中为自动并行识别同的,介绍的是数据收集函数Ｃｏｌｌｅｃｔ算法及其设计优化以及对原有算法所作的结构性改进,主要思想是将存储转发机引入到数据收集算法中,从而省去了大量的数据填充及抽取操作。     

传感网中延迟限定的非汇聚数据移动式收集

在大规模的无线传感器网络中收集数据,不仅需要考虑节点的能量消耗,而且还需要考虑数据收集延迟.如何有效地均衡节点的能量消耗,同时最小化数据收集延迟,是一个具有挑战性的问题.为了均衡节点的能量消耗,利用移动数据收集器收集数据.以此为基础,提出一种DC-Collection算法来解决数据收集延迟和能耗的问题.首先,在网络中构造最短路径树,网络非连通时,不同的网络子图可以构造多棵最短路径树,它们构成一个最短路径树集合;其次,在每一棵最短路径树上选取部分节点作为采集节点和逗留节点,使得以采集节点为根的限高树的高度不超过h,且在每个采集节点的通信区域内至少有一个逗留节点;再次,在每棵限高树内调整树的结构,让能量高的节点承担更多的子孙节点,最大化限高树的生命周期;最后,移动数据收集器从Sink出发,遍历逗留节点所在位置收集数据,最终回到起点,并将数据发送给Sink.通过理论分析和大量仿真实验,其结果表明:与现有的数据收集协议相比,DC-Collection不仅能够均衡各节点的能量消耗从而延长网络生命周期,而且能够缩短移动数据收集器收集数据行走的路径长度,从而缩短数据收集延迟.