• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.548-550
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• 2003

EJB(Enterprise Java Bean) 컨테이너에서 대규모의 요청을 위해서는 여러 개의 EJB 컨테이너를 클러스터링 환경으로 구동시키는 것이 필요하다. EJB를 사용하는 클라이언트로는 JSPP나 에플리케이션 클라이언트, 혹은 또 다른 빈이 될 수 있다 이러한 클라이언트가 사용하는 EJB의 스텁을 클러스터 환경에 적합하도록 구현함으로써 트랜잭션 지역화, 장애 발생시 다른 서버로의 메소드 호출 전환, 동일 가상 머신을 탐지한 메소드 호출 최적화 등의 다양한 기능을 수행할 수 있다. 본 논문에서는 이러한 스마트 스텁의 필요성 및 구현에 대해 논의한다.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.671-682
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• 2004

As new and diverse information technologies are being introduced and software complexity is increased, software development cost and efforts are also sharply increased. Component-Based Development (CBD) technology is appealing as a new way to reduce the cost and effort by increasing reusability and maintainability. Component in CBD has variability infernally which enables customization of the component within the specific domain. A component user can easily set up internally variability parts though Required interface which is provided by the component. Enterprise JavaBeans (EJB) is utilized as a commercial standard to implement Java-based components. However, EJB constructs are limited in directly implementing Required interfaces of coarse-grained components［8］. In this paper, we define Required interface and propose interface-storage technique, class-storage technique, interface-generation technique, and Plug -in technique for implementing required interface of component. Interface-storage technique stores variable value in Required interface and class-storage technique take the Bean containg variability as Required interface without modification of component model. Interface-generation technique generates new Bean which takes the role of Required interface for component variability and Plug-in technique sets up component variability that component user plugged-in variable part externally The proposed four techniques conform to the semantics of CBD component interface and enable the implementation of high quality components.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1025-1036
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• 2003

In industry, it is a current trend that systems are developed by using Enterprise JavaBeans(EJB) technology for reducing the cost and the time. Thus, the architecture of EJB is getting more essential to enhance reusability, extensibility and portability of system. However little has been studied in the realm of the practical software architectures for EJB. The architecture has just bean studied in abstract level, but not in concrete level providing the method to substantiate it using the practical J2EE techniques. Just using the EJB technology doesn't guarantee the reusability of the artifacts because EJB specification provides the characteristics and architecture for only fine grained components as session and entity bean. In this paper, we propose the enterprise software architecture for the systems based on EJB and the concrete techniques for implementing that. Also, design patterns of modeling efficient enterprise architecture are represented. By analyzing both the strengths and the weaknesses of suggested design patterns, EJB design patterns which are suitable for each layer of enterprise architecture will be identified. Through the component which design patterns are applied, the architecture can support the optimized relationship between the components. Five techniques for designing components from fine grained to coarse grained based on EJB technology, and architecture design techniques including transaction and assembling techniques are proposed.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2000.11a
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• pp.635-645
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• 2000

Within a context of rapid technological change and shifting market conditions, the education environment requires new paradigm of education delivery In accordance of such a technological progress, distance education system, which makes the loaming take place at anytime anywhere, overcoming barriers of time, or distance, is emerging as a mainstream of education delivery replacing the convectional one way delivery system from instructor to learners. This Paper aims to introduce the development principle and algorithm about Instructional System Design(ISD) module, a part of a total solution for distance education services. It was developed on Linux, a free Unix-type operating system. Linux supports so various network protocols, sharing the network resources in a smooth way, that it is able to integrate with other operating system very easily, especially with Windows NT or Windows 2000 servers. In terms of quality, it never falls behind the windows products which are commercially available only, It is a right operating system for the such a school environment that is usually limited in budgets. The development environment of the distance education solution to which ISD module belongs is composing of Apache server for web server, Java bean based on components for ISD module, PHP, server-side scripting language, for HTML documents and MySQL for DBMS.

• Journal of KIISE:Software and Applications
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• v.30 no.5_6
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• pp.529-539
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• 2003

Due to the emersion of J2EE (Java 2, Enterprise Edition), many enterprises inside and outside of the country have been developing the enterprise applications appropriate to the J2EE model. With the help of the component model of Enterprise JavaBeans (EJB) which is the J2EE core technology, we can develop the distributed object applications quite simple. EJB application can be implemented by using the component-oriented object transaction middleware and the most applications utilize the distributed transaction. Due to these characteristics, EJB technology became popular and then the study for EJB based application has been done quite actively. However, the research of techniques for the performance monitoring during run-time of the EJB applications has not been done enough. In this paper, we propose the techniques for monitoring the performance of EJB Application on the run time. First, we explore the workflow for the EJB application service and classily the internal operation into several elements. The proposed techniques provide monitoring the performance elements between the classified elements. We can also monitor by extracting the performance information like state transition and process time of the bean which is related to the lifetime occurred during one workflow, and the resource utilization rate.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1969-1972
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• 2002

소프트웨어 재사용 기술은 소프트웨어공학 분야의 오래된 주제로 단순한 복사 및 붙이기(copy & paste)에서 현재의 소프트웨어 컴포넌트 기술에 이르기까지 계속해서 연구되고있다. 재사용의 단위를 무엇으로 하냐에 따라 또는 소프트웨어 개발 주기 중 어느 단계의 산출물을 재사용 하느냐에 따라 다양한 개념과 기법들이 소개되었으며 실제 소프트웨어 개발에 활용되고 있다. 또한 컴퓨팅 환경의 변화에 보조를 같이하여 특정 어플리케이션을 지원하는 재사용기술 들이 등장하고 있다. 본 논문에서는 웹(Web) 기반의 프로그램에 소프트웨어 컴포넌트 재사용 기술을 접목하고자 한다. 수없이 많은 웹 기반 어플리케이션들이 개발되었고 또한 개발되고 있으며 다른 컴퓨팅 환경에서 운영되는 다양한 기존 시스템들도 웹 기반으로 옮겨가고 있다. 본 논문의 목적은 기 개발된 웹 프로그램에서 재사용 가능한 모듈을 컴포넌트 화하여 차후 웹 프로그램 개발 시에 재사용될 수 있도록 하는 것이다. 웹 지원 언어 중 Sun 사의 서블릿(Servlet)[1]으로 개발된 어플리케이션들을 EJB(Enterprise JavaBeans)[2] 환경으로 변환시키기 위한 기법과 이를 지원하는 도구를 소개한다. 본 논문에서 소개하는 도구는 크게 분석기, 시각화기, 추출기, 생성기, 및 전개기로 구성되며 해당 모듈에서 입력받은 서블릿을 처리하며 최종적으로 세션 빈(session bean)[2] 또는 엔터티 빈(entity bean)[2]과 같은 EJB 컴포넌트를 생성한다.

• Journal of The Korean Association of Information Education
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• v.9 no.1
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• pp.49-55
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• 2005

Web-Based instruction system embodied according to traditional process until present. But, these method have inefficiency in system development and give trouble of operation and administration after development. Therefore, It need induction of component based development in Web-Based instruction system. In this research, I constructed score processing system by component composition. I embodied component by Java Beans and used C2 architecture at the composition method. In this result, I shown in application possibility of component based development in Web-Based instruction system as to construct whole score processing system through composition of each component.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.2
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• pp.220-225
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• 2000

A general household survey was carried out in the village of Sonoageng in East Java, Indonesia with the aim to assess their socio-economic status, and the crop and livestock production system prevailing in the area. Of the households interviewed (164), 52% are landless, 35% own land or have a combination of own and shared land, and 12% do not own land but have access to land by sharing. Nearly two thirds (65%) of the households raise cattle; most of them own animals, 8% reared shared animals only. The dominant crop was rice; other crops grown were soya bean, groundnut, maize and sugar cane. Nearly half (47%) the household income was derived from off-farm work (non-agricultural activities), 33% from crops, 13% from livestock (mainly cattle), and 7% from agricultural labour. Most households kept 1 to 2 animals and only 21 out of 164 households earned more than Rp. 500,000 (~250 US$) per annum from livestock. The most prevalent type of livestock production in the area could be characterized as small-scale cow/calf operation, either by landless households or those with <0.4 ha of land.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.361-364
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• 2002

EJB(Enterprise JavaBeans)는 서버 상의 Java 컴포넌트와 그 컴포넌트를 위한 동작 환경을 제공하는 전체 프레임웍(Framework)이다. EJB 에서 동작하는 컴포넌트를 엔터프라이즈 빈(Enterprise Bean)이라고 하고, 그 컴포넌트가 동작하기 위한 환경을 컨테이너(Container)라 한다 EJB 에서는 기존에 개발자가 직접 컴포넌트로 제공해 주어야 하는 트랜잭션, 영속성, 보안문제, 데이터베이스 연결 풀링, 쓰레딩 관리 같은 기능을 컨테이너에서 처리해 줌으로 일반 개발자는 복잡한 하부 로직에 신경쓰지 않으면서 더 쉽고 빠르게 동일한 기능을 구현할 수 있게 된다. 본 논문에서는 이러한 EJB 컨테이너를 설계함에 있어서 하나의 중요한 요소인 트랜잭션 관리에 관한 설계를 논한다.

• The KIPS Transactions:PartD
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• v.9D no.2
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• pp.329-336
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• 2002

With the fast development of Internet environment, e-Commerce is rapidly increasing. n the expanding e-Commerce environment, the need for a new e-Commerce systems what will deliver products to the customer rapidly and increase sales is growing bigger. Recently, these requirements brought many researches on recommender systems. However, until now, those recommender systems have a limit because it takes too much time for recommender systems to give customers the recommendations in real time, if the number of purchase data of customers is large. So this paper concerns on the recommender systems using collaborative filtering as one of the solutions to increase the competitive power. We proposed and experimented the more improved recommender systems which could decrease the data size to shorten the recommending time by using the representative category of the product which customers want to buy. Also, we design and implement a recommender system using Enterprise JavaBeans.