• 정보기술과데이타베이스저널
• /
• 제7권2호
• /
• pp.1-15
• /
• 2000

The World-Wide-Web have many advantages as a front-end of database systems. Hence in Internet applications, such as E-Commerce systems, the requirements for Web-based database applications have been increasing. In this work we propose a framework for java-based Web database applications-JaWAF(Java-based Web Application Framework). JaWAF has the 3-tier architecture of Client/Server, and consists of database gateway, application server, and communication and message component. When this framework is applied to the database applications developments, it can provide advantages, such as ease understanding and fast implementations of the Web applications. Thus we can build 3-tier Web-based database application systems with high scalability and distributed processing capability. Database gateway in JaWAF works as a daemon process that connects to the database systems and waits for requests from clients, and supports state-oriented service between clients and database servers. Hence the performance of Web applications could be increasing.

• 한국데이타베이스학회:학술대회논문집
• /
• 한국데이타베이스학회 1994년도 DB산업기술 활성화를 위한 학술대회 및 기술 심포지움
• /
• pp.49-69
• /
• 1994

A client/server system has become the computing architecture for the business organization which seeks competitive edges. Technically, a client/server system places application processing close to the user and thus increases performance. This paper's two primary goals are (i) to present a performance model for client/server database systems and (ii) to demonstrate analytically the effectiveness of client/server computing in comparison with other computing architectures via an illustrative example. The model is most likely to be used as a practical performance guide for client/server computing.

• 한국멀티미디어학회논문지
• /
• 제7권9호
• /
• pp.1329-1338
• /
• 2004

데이터마이닝은 방대한 데이터로부터 다차원적인 정보를 추출하는 것이다. 방대하게 구축되어 있는 데이터베이스에서 임의의 테이블의 컬럼에 대해 참조 할 수 있는 정보는 단순하게 컬럼명과 자료형 혹은 간단한 주석 정도이다. 그러한 비구조적이고 빈약한 내용만으로는 데이터마이닝을 위한 자료수집 및 자료탐색 단계에서 컬럼의 용도와 특성 및 스키마를 파악하여 데이터를 정제하고 수집하는 것이 난해 할 뿐만 아니라 너무 많은 시간이 소요된다. 이러한 문제를 해결하기 위해 본 논문에서는 관계형 데이터베이스 환경에서 데이터준비 단계 에 대부분의 시간을 소요하는 문제를 해결하기 위한 방안을 제안한다. 즉, 데이터 준비 단계에서 유용한 요소들을 메타데이터의 표준인 ISO/IEC : 11179 MDR (MetaData Registry) 규격에 맞는 표준 메타데이터를 제안하고, 이기종 및 이질 DBMS간에 호환 가능한 XML 기반의 분산 MDR 검색 시스템 구조를 제안한다.

• Asia pacific journal of information systems
• /
• 제8권3호
• /
• pp.21-36
• /
• 1998

Group collaborative systems are recently emerging to support a group of users engaged in common tasks such as group decision making, engineering design, or collaborative writing. Simultaneously, as communications networks and distributed database systems become core underlying architecture of the organization, the need of collaborative systems are gaining more attentions from industry. In such collaborative systems, as the shared objects may evolve constantly or change for operational purposes, providing the users with synchronized and consistent views of the shared object and maintaining the consistency between shared object and replicated objects are important to improve the overall productivity. This paper provides an change management framework for the group collaborative systems to facilitate managing dependency relationships between shared objects and dependents, and coordinating change and propagation activities in distributed computing environments. Specifically, the framework adopts an object-oriented database paradigm and presents several object constructs capturing dependency management and change notification mechanisms. And the proposed framework accommodates both persistent dependents such as replicated data and transient dependents such as various user views in a single formalism. A prototype system is developed on a commercial object-oriented database management system called OBJECTSTORE using the C++ programming language.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2008년도 추계학술발표대회
• /
• pp.1103-1106
• /
• 2008

Data Grid is a kind of Grid computing provides the cooperative environment through the distributed data sharing, and can manage the massive data easily and efficiently. We designed and implemented Globus Toolkit4 (GT4) based database access and integration service (GDAIS). This service was implemented as Grid service for run on the GT4 which is Grid middleware. And it provides functions which are automatic registration of database in virtual organization, distributed query service, and the unified user interface. Also this system can use components which are provided from GT4. Therefore it can improve the efficiency to distribute and manage databases, can easily access and integrate of the distributed heterogeneous data in Grid environments.

• ETRI Journal
• /
• 제22권1호
• /
• pp.1-11
• /
• 2000

The Satellite Operation System (SOS) has been developed for a low earth orbiting remote sensing satellite, Korea Multipurpose Satellite-I, to monitor and control the spacecraft as well as to perform the mission operation. SOS was designed to operate on UNIX in the HP workstations. In the design of SOS, flexibility, reliability, expandability and interoperability were the main objectives. In order to achieve these objectives, a CASE tool, a database management system, consultative committee for space data systems recommendation, and a real-time distributed processing middle-ware have been integrated into the system. A database driven structure was adopted as the baseline architecture for a generic machine-independent, mission specific database. Also a logical address based inter-process communication scheme was introduced for a distributed allocation of the network resources. Specifically, a hotstandby redundancy scheme was highlighted in the design seeking for higher system reliability and uninterrupted service required in a real-time fashion during the satellite passes. Through various tests, SOS had been verified its functional, performance, and inter-face requirements. Design, implementation, and testing of the SOS for KOMPSAT-I is presented in this paper.

• 농촌계획
• /
• 제12권4호
• /
• pp.53-61
• /
• 2006

Rural amenity resources consist of natural, cultural and social resources. Some of resources have been surveyed in other institutes and organizations and information system about these resources has been constructed. Integrating with information of existing system or database is helpful to produce useful rural amenity resources information to users. This integration of distributed information is based on semantic integration. In this paper, we used ontology for semantic integration and introduced the method of external information integration using ontology. We designed ontology table to represent ontology in database and integrated distributed information using ontology. To examine the improvement of information service efficiency and the applicability, rural amenity resources information and tourist attraction information database were constructed and integrated. Also, the information service efficiency with information integration was evaluated using recall ratio and compared to the information service efficiency without information integration.

• 한국전자거래학회:학술대회논문집
• /
• 한국전자거래학회 2003년도 종합학술대회 논문집
• /
• pp.249-254
• /
• 2003

Object caching is a desirable feature to improve the both scalability and performance of distributed application systems for information infrastructure, the information management system leveraging the power of network computing. However, in order to exploit such benefits, we claim that the following problems: cache server placement, cache replacement, and cache synchronization, should be considered when designing any object cache system. We are under developing DOC: a Distributed Object Caching, as a part of building our information infrastructures. In this paper, we show how each problem is inter-related, and focus to highlight how we handle cache server deployment problem

• 한국국방경영분석학회지
• /
• 제23권2호
• /
• pp.25-44
• /
• 1997

Internet users been rapidly increased due to the convenient GUI environment. Current Web-based HTTP/CGI client/server architecture has several problems such as the CGI bottleneck, no maintaince of state, and no load balancing. However, with Java and CORBA technologies called“Object Web technology”, we can solve them because Java is not only a mobile code but also a platform-independent code, and CORBA has ability to build distributed object and language-independent object model. The goal of “Object Web technology”is to create multivendor, multiOS, multilanguage“legoware”using objects. This paper implement“Book Search System”which is Web-based client/server architecture using distributed objects. Environments of this implementation are Hangul Windows NT(included IIS) server, Hangul Windows 95 client, Visigenic's VisiBroker for Java 1.2 which is a product of CORBA 2.0, HTTP protocol on TCP-IP-based, Sybase SQL Anywhere 5.0 database server, and the interface between application server and database is JDBC-ODBC bridge middleware.

• Asia pacific journal of information systems
• /
• 제5권2호
• /
• pp.101-129
• /
• 1995

This paper proposes a form-based distributed database design methodology ($FD^3$). The methodology consists of five design phases such as (i) form requirement analysis (ii) schema integration (iii) distribution analysis (iv) distribution design, and (v) local logical/physical design. In the $FD^3$, all the important design information for each phase is obtained by using an organizations forms, Users requirements are analyzed by using forms that contain logical and quantitative information for distribution design. $FD^3$ resolves naming conflicts by employing SQLs based on the form field data in the schema integration phase. Furthermore, $FD^3$ enhances the quality of distributed database design by incorporating communication costs into the design model. A real-life case is illustrated to demonstrate the usefulness of the $FD^3$.