分布式电源监控信息管理系统设计

针对分布式电源(DG)随机性、波动性大,可调、可控性弱的特点,设计一套用于分布式电源监控的信息管理系统,实现状态监测、数据采集、故障报警、历史数据管理与趋势分析等功能。系统基于C/S架构,采用死区限值压缩、LZW字典压缩等数据压缩方法,建立关系数据库与实时数据库并存的数据库系统,对分布式电源的瞬时量信息（U/I/f/P/Q）、电能累积信息、事件信息（启停、越限等）进行数据采集、分析和存储,并能够以图形、语音等多种形式报警。     

一种适合多用户并发访问的影像存储模型

针对传统的遥感影像金字塔一体化存储模型在多用户并发访问应用中的存在的问题,提出一种适合多用户并发访问的可分离式存储模型,通过数据的分布存储和访问处理任务的分解、转移,提高数据服务器的I/O性能和响应效率。实验结果证明了该模型的有效性,且模型系统具有较高的可扩展性和稳定性。     

Data resource selection in distributed visual information systems

With the advances in multimedia databases and the popularization of the Internet, it is now possible to access large image and video repositories distributed throughout the world. One of the challenging problems in such access is how the information in the respective databases can be summarized to enable an intelligent selection of relevant database sites based on visual queries. This paper presents an approach to solve this problem based on image content-based indexing of a metadatabase at a query distribution server. The metadatabase records a summary of the visual content of the images in each database through image templates and statistical features characterizing the similarity distributions of the images. The selection of the databases is done by searching the metadatabase using a ranking algorithm that uses the query's similarity to a template and the features of the databases associated with the template. Two selection approaches, termed mean-based and histogram-based approaches, are presented. The database selection mechanisms have been implemented in a metaserver, and extensive experiments have been performed to demonstrate the effectiveness of the database selection approaches     

多数据库系统中查询分解算法的研究

多数据库系统允许用户使用一个集成模式和简单的全局查询语言同时访问多个异构的、自治的数据库系统。全局查询分解处理是多数据库系统中的一个很重要的问题。本文给出了一种多数据库环境中的模式信息管理方法,基于这些模式信息,我们提出一种易于实现的查询分解算法。由于多数据库查询分解处理与模式集成的实现紧密相关,所以本文对多数据库系统的模式集成作了一些描述。     

面向流数据的数据管理系统的研究

传统关系数据库系统通常用来存储没有时间概念的相对静止的数据, 对于一些新的应用领域, 信息是以数据序列的形式产生并且需要实时地、持续地进行处理, 这就超出了传统系统的解决能力。数据流数据管理系统是面向流数据而设计的数据管理系统, 它能有效地处理输入流数据并提供持续检索的功能。从整体上分析数据流管理系统的体系结构, 重点讨论基于流数据的数据模型和流查询。     

Electronic data acquisition forms in construction management

Effective management of construction projects depends on good access to and control of data, especially data pertaining to cost and schedule control functions. However, the proper design and development of automated mechanisms have not had the facility to acquire and store quality data in a timely manner. The purpose of this paper, then, is to discuss a prototype, automated data acquisition system that was developed to support an integrated project management system. The data acquisition system is composed of an integrated set of electronic forms used in conjunction with a bar coding data-entry tool.     

基于MongoDB的分布式缓存

电力信息化的发展对传统电力信息系统的数据处理、并发请求及响应能力提出诸多挑战.针对电力信息系统数据处理的特点,提出一种基于MongoDB数据库的分布式缓存,并对该分布式缓存的运行机制、服务端架构和客户端功能模块的设计进行了分析与阐述.基于MongoDB的分布式缓存能够有效地降低电力信息系统数据库层的访问负载量,提高系统的整体性能,它采用分布式文件存储缓存数据,支持数据冗余备份和故障恢复功能,具有较高的可靠性和扩展性.基于MongoDB的分布式缓存已成功应用到电力某企业的项目管理系统中.     

面向数据绑定的表格建模研究与实现

表格作为结构化数据的一种最常用的表现形式,已被各个行业广泛应用在信息管理系统中.表格的自动生成和处理技术也成为应用信息系统设计和实现中的关键技术.随着Internet和Web技术的发展,Web与传统的数据库系统、文档管理系统结合在一起构成了巨大的、异构的、分布式的数据仓库.海量信息和异构信息的处理对表格的数据建模和处理技术提出了新的要求.针对现有技术在表格建模方面存在的模型结构简单,支持的表格类型有限和缺乏对集成异构数据源的支持等缺陷,本文在从设计和实现方面分析现有各种信息系统对表格处理技术的需求基础上,提出了一种面向数据绑定的新型表格建模方法以及相关技术,从而满足数据层和显示层在数据源类型、数据集成和组织方式等方面的多种需求.     

A hospital integrated framework for multimodality image basemanagement

The trend in healthcare information technology is increasingly digital and multimedia oriented. The next generation of health care information systems will consist of a vast network of heterogeneous, autonomous, and distributed imaging scanners, databases, information systems, knowledge intensive applications, and large quantities of multimedia medical data. A key challenge facing system researchers and builders is to provide a new organizational framework that can integrate this varied collection of resources into what appears to be a uniform and logical conglomeration of data and knowledge store in order to increase the availability of global or previously nonaccessible information and to address demanding new information processing requirements for diverse image-assisted medical applications. The purpose of this paper is to present the authors' research toward the development of a hospital integrated framework of multimodality image base management (MIBM) for digital radiology of the future. This evolutionary framework consists of three hierarchical components: a hospital-integrated picture archiving and communication system (HI-PACS), a medical image database system (MIDS), and a set of image-based medical applications that relies on the support of MIDS and PACS. In this paper, the authors describe the system architecture, guiding principles, and design specifications of HI-PACS and MIDS and illustrate their functions and capabilities with three implemented applications, namely, patient folder workflow, distributed object management, and multimodality imaging studies. In addition, the authors conclude their findings with a summary of challenges and research directions     

Databases deepen the Web

The Web has become the preferred medium for many database applications, such as e-commerce and digital libraries. These applications store information in huge databases that users access, query, and update through the Web. Database-driven Web sites have their own interfaces and access forms for creating HTML pages on the fly. Web database technologies define the way that these forms can connect to and retrieve data from database servers. The number of database-driven Web sites is increasing exponentially, and each site is creating pages dynamically-pages that are hard for traditional search engines to reach. Such search engines crawl and index static HTML pages; they do not send queries to Web databases. The information hidden inside Web databases is called the "deep Web" in contrast to the "surface Web" that traditional search engines access easily. We expect deep Web search engines and technologies to improve rapidly and to dramatically affect how the Web is used by providing easy access to many more information resources.     

Dispatching mobile Agents for DDM applicationss

Techniques for mining information from distributed data sources accessible over the Internet are a growing area of research. The mobile Agent paradigm opens a new door for distributed data mining and knowledge discovery applications. In this paper we present the design of a mobile agent system which couples service discovery, using a logical language based application programming interface, and database access. Combining mobility with database access provides a means to create more efficient data mining applications. The processing of data is moved to network wide data locations instead of the traditional approach of bringing huge amount of data to the processing location. Our proposal aims at implementing system tools that will enable intelligent mobile Agents to roam the Internet searching for distributed data services. Agents access the data, discover patterns, extract useful information from facts recorded in the databases, then communicate local results back to the user. The user then generates a global data model through the aggregation of results provided by all Agents. This overcomes barriers posed by network congestion, poor security, and unreliability.     

Using object deputy model to prepare data for data warehousing

Providing integrated access to multiple, distributed, heterogeneous databases and other information sources has become one of the leading issues in database research and the industry. One of the most effective approaches is to extract and integrate information of interest from each source in advance and store them in a centralized repository (known as a data warehouse). When a query is posed, it is evaluated directly at the warehouse without accessing the original information sources. One of the techniques that this approach uses to improve the efficiency of query processing is materialized view(s). Essentially, materialized views are used for data warehouses, and various methods for relational databases have been developed. In this paper, we first discuss an object deputy approach to realize materialized object views for data warehouses which can also incorporate object-oriented databases. A framework has been developed using Smalltalk to prepare data for data warehousing, in which an object deputy model and database connecting tools have been implemented. The object deputy model can provide an easy-to-use way to resolve inconsistency and conflicts while preparing data for data warehousing, as evidenced by our empirical study.     

基于XML的.NET通用数据访问模型的研究

.NET的数据访问模型利用通用数据接口,实现对异构数据库的管理和数据存储。但是,它缺乏对文件系统的集成,不能实现完全的信息共享。该模型实现文件系统和异构数据库系统的集成,在一定程度上能解决这一问题。     

新型数据管理系统研究进展与趋势

随着各类新型计算技术和新兴应用领域的浮现,传统数据库技术面临新的挑战,正在从适用常规应用的单一处理方法逐步转为面向各类特殊应用的多种数据处理方式.分析并展望了新型数据管理系统的研究进展和趋势,涵盖分布式数据库、图数据库、流数据库、时空数据库和众包数据库等多个领域.具体而言：分布式数据管理技术是支持可扩展的海量数据处理的关键技术;以社交网络为代表的大规模图结构数据的处理需求带来了图数据库技术的发展;流数据管理技术用来应对数据动态变化的管理需求;时空数据库主要用于支持移动对象管理;对多源、异构而且劣质数据源的集成需求催生出新型的众包数据库技术.最后讨论了新型数据库管理系统的未来发展趋势.     

Design and implementation of national engineering education delivery system (NEEDS)

Educational course material is constantly being developed by professors. More and more of this course material is now on computers. It is often desirable for this material to be available through computer networks to the widest possible audience. Given a general audience, this access should be quick and simple. The National Engineering Delivery System (NEEDS) is a new courseware development and distributed system which allows faculty, students, industry and other users to easily access a large number of diverse courseware modules in an effective and efficient manner. This paper documents the design and implementation of a system that may make this idea a reality. The work includes the development of databases used to store course material information, the design of an efficient communication networking protocol for delivering courseware modules, and the development of user front-ends for general access to the course material stored in the databases.     

区块链的数据管理技术综述

最近几年,随着加密货币和去中心化应用的流行,区块链技术受到了各行业极大的关注.从数据管理的角度,区块链可以视作是在一个分布式环境下众多不可信节点共同维护且不可篡改的账本.由于节点间相互不可信,区块链通过共识协议,确保数据存储的一致性,实现去中心化的数据管理.针对区块链的安全性以及共识协议,已有诸多工作进行全面的分析.将从数据管理的角度,分析区块链技术与传统数据库下数据管理技术的异同.分布式数据管理的研究已经持续数十年,涵盖了数据存储模式、事务处理机制、查询执行与验证、系统可扩展性等诸多方面,并已有诸多技术广泛应用于实际的分布式数据库中.该类工作往往假定存在中心可信节点或者节点只可能发生崩溃而不存在恶意攻击.然而在区块链环境中,系统设计需考虑不可信节点可能的攻击行为以及拜占庭容错.这给数据管理带来了新的问题与挑战.因此,将梳理并分析国内外有关区块链数据管理的文献,并展望未来的研究方向.     

The Pegasus heterogeneous multidatabase system

Pegasus, a heterogeneous multidatabase management system that responds to the need for effective access and management of shared data across in a wide range of applications, is described. Pegasus provides facilities for multidatabase applications to access and manipulate multipole autonomous heterogeneous distributed object-oriented relational, and other information systems through a uniform interface. It is a complete data management system that integrates various native and local databases. Pegasus takes advantage of object-oriented data modeling and programming capabilities. It uses both type and function abstractions to deal with mapping and integration problems. Function implementation can be defined in an underlying database language or a programming language. Data abstraction and encapsulation facilities in the Pegasus object model provide an extensible framework for dealing with various kinds of heterogeneities in the traditional database systems and nontraditional data sources     

通过OLE实现数据库中的多媒体数据管理

概述了关系数据库系统存储和处理复杂数据的一些问题，讨论了使用ＯＬＥ实现数据库中的多媒体数据管理及其解决方案，给出了信息系统中的具体实现。     

Interfacing a commercial drug-interaction program with an automated medical record.

The utility of drug-interaction software is limited by the fact that products on the market are unable to interface with preexisting stored medication lists, so that it is necessary to record medication lists twice. With the variety of automated medical records now in existence, it may be impractical for vendors of drug-interaction software to provide enough interfaces to overcome this problem. However, if vendors allowed greater access to their drug-interaction data, existing automated records could easily be altered to incorporate this clinically relevant information. This article describes a commercially available drug-interaction software package and the logic used to build an interface to a preexisting automated medical record.