• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.543-545
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• 2000

분산 이기종 시스템간에 어플리케이션을 개발하기에 적합한 미들웨어로 OMG가 제안한 CORBA가 많이 사용되고 있는데, CORBA는 객체들 간에 멀티캐스트 통신을 지원하지는 못한다. 따라서 멀티캐스트 통신을 지원하기 위해 기존의 분산시스템에서 그룹서비스를 CORBA에 통합하기 위해 많은 연구가 진행되고 있다. 본 논문에서는 CORBA를 기반으로 한 그룹서비스와 그룹서비스의 관리로서 뷰의 관리와 시퀸스 객체를 통한 메시지 순서성 보장을 위한 방법을 제안한다.

• Journal of Internet Computing and Services
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• v.2 no.3
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• pp.93-98
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• 2001

It is difficult to develop Electronic Commerce System due to expansion, maintenance and repair of the system. In this paper, the author proposes 3-Tier structure Stock Market Management System using JAVA and CORBA. The event service of CORBA supports the interactive environment. For improvement of expansion, performance, security, maintenance, repair. and efficiency, the 3-Tier structure Stock Market Management System is implemented using CORBA and JDBC middle ware in this environment.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.549-551
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• 2000

CORBA는 이종의 분산 컴퓨팅 환경에서 재사용성, 이식성, 상호 운용성을 유지하며 통합할 수 있는 환경을 제공한다. 그러나 표준 CORBA는 객체 복제를 이용하여 지원할 수 있는 결함 감내와 고 가용성을 지원하지 못한다. 지금까지의 CORBA 기반 그룹 통신에 관한 연구들은 CORBA 애플리케이션 프로그래머가 그룹 통신 프로토콜을 직접 이용할 수 있는 방법이 없었다. 또한 CORBA 또는 OS의 수정이 요구되거나, 기존의 다양한 그룹 통신 프로토콜을 적용할 수 없었다. 본 연구에서는 상호 운용성, 기존 그룹 통신 프로토콜의 재사용, ORB와 OS에 대한 독립성을 유지하고, 유연성 있는 하부 프로토콜 적용을 가능하게 하는 OCI를 확장함으로써, 표준 CORBA의 수정 없이 다양한 그룹 통신 프로토콜을 적용할 수 있는 그룹 통신 프레임웍을 제안한다.

• Journal of Korea Spatial Information System Society
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• v.2 no.1 s.3
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• pp.5-16
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• 2000

OGC(Open GIS Consortium) suggests the 'OpenGIS Simple Feature Specification for CORBA' which is the OpenGIS implementation specification for CORBA to specify standard interfaces for reuse and interoperation among distributed heterogeneous GIS resources in the CORBA distributed computing environment. An OpenGIS server that supports this implementation specification moat correctly implement all interfaces defined in the OpenGIS implementation specification to be interoperable with wrapped GISs efficiently. In this paper, we have designed and implemented an OpenGIS server based an object relational GIS, called GEUS that integrates GIS and database technologies to provide spatial data types and spatial operators from the DBMS engine level. In the CORBA distributed computing environment, clients can access geospatial data stored in GIS wrapped by the OpenGIS server through the standard interfaces defined in the OpenGIS implementation specification for CORBA. In addition, clients can use geospatial operation features provided by a back-end GIS and interoperate with other GISs.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.8
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• pp.372-378
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• 2001

오늘날, 이질적인 분산 컴퓨팅 환경을 통합하고 분산 공유 자원을 효율적으로 사용할 수 있는 공통 작업 환경에 대한 요구가 날로 높아지고 있다. 이러한 연구 중에서 주목받는 것 중 하나가 OMG의 CORBA이다. CORBA 시스템에서 실시간 멀티미디어 데이터들을 처리하기 위해 확장된 CORBA 표준을 RT(Real-Time) CORBA라고 한다. RT CORBA의 핵심은 수많은 실시간 태스크들의 블록을 최대한 방지하여 실시간 QoS를 보장해 줄 수 있는 실시간 스케쥴링 기법에 있다고 할 수 있다. 현재 RT CORBA를 위해 제안되는 많은 스케쥴링 기법들은 대개 이전의 단일 시스템에 기반한 전역 우선순위 기반 스케쥴링이 대부분이다. 하지만 이러한 Soft Real-Time 스케쥴링은 다양한 성능 요소가 산재하는 분산 시스템에서는 그 성능을 보장할 수 없다. 본 논문에서는 CORBA와 같은 분산시스템의 보편적 특성을 고려한 Hard Real-Time 스케쥴링 기법인 CII(Cut In Interval) 기법을 제안하였다. 기존의 전역 우선순위 바탕의 스케쥴링이 비효율적인 태스크 할당 및 지역 스케쥴링을 제공하지만, CII 기법의 스케쥴링은 간단하면서도 보다 효과적인 전역 스케쥴링을 제공할 수 있다. CII 기법의 핵심은 이미 스케쥴링된 태스크를 가능한 제한시간까지 연기하여 얻어진 여유시간을 다른 실시간 태스크들의 처리에 활용하자는 것이다. 이러한 여유시간의 활용은 제안한 기법이 기존의 기법과 달리 보다 능동적이고 효율적인 스케쥴링 기법임을 증명한다.

• The KIPS Transactions:PartA
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• v.10A no.3
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• pp.231-238
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• 2003

Distributed systems present new system architecture for solving interoperability problem in heterogeneous system. This paper presents CORBA Inter-ORB protocol model based on shared memory to support communication software through analysis of existing CORBA IIOP protocol performance and Inter-Process Communication techniques. In the same host environment, proposed model applied standard CORBA mechanism to minimize message transfer overhead can develop software independently to hardware architecture of target communication system. This communication software that has flexibility and extensibility can improve productivity, duality and reusability of software.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.479-484
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• 2002

This paper presents the model that integrates an SDL system and a CORBA system using mapping rules between method and signal for developing embedded systems connected with internet. In order to support communication between the two different systems (SDL and CORBA), it is essential to secure the conversion interface between SDL communication protocol and CORBA communication protocol. In this paper, IDL is adopted for the communication interface and the conversion of the communication protocol between the two systems, and the IDL compiler automatically generates the interface for protocol interoperability. The proposed model adopts middleware on the subpart of the SDL based legacy system, and hence, supports the service on the distributed system, regardless of the environment and location of the server system.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.2
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• pp.37-45
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• 1999

CORBA IDL and RMI, the representative of distributed object model, support different approaches for distributed computing environments. CORBA approach does not support the application generated by RMI, even though it supports multiple programming languages. Object translation system between RMI to CORBA is designed and implemented for interoperability of distributed objects on the two different distributed programming environments. Suggested system is considered binding, inheritance, polymorphism, object passing, and callback which are key properties on the distributed objects. To validate the usefulness of the proposed system, we adopt a model for distrubuted objects and implement it as an application on the RMI environment. And, we translated it to an application on the CORBA environment. We observed the performance of translated application in the respect of inheritance, object passing, polymorphism across the machine boundary. Experiments showed that performance of distributed objects, those generated by translation system and those implemented on the CORBA environment, is equivalent.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.477-480
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• 2002

Transparency of position that provide quick service regardless of physical position to users in distribution computing environment is getting into prominence and is developed in component form that many application softwares take advantage of distributed object technology. Because design object in distribution computing environment and OMG introduces OMA for embody, defined CORBA by standard of distributed object technology on OMA's abstract picture object model. Security service in CORBA platform is very important. Present object security service in distribution computing environment that refer standard of sorority and security models of distribution computing platform in CORBA in this treatise and follow in CORBA security service rules.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.3
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• pp.79-94
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• 1997

OMG (Object Management Group) published a security service specification, called CORBA (Common Object Request Broker Architecture) security reference model because the integration of security and object-oriented techniques was critical for successful deployment of distributed object systems. The CORBA security reference model treats access control as an implementation independent semantic concept but has incomplete semantics of the access control function. Because of such imcompleteness it is difficult for the system administrator and the CORBA security implementor to have the same understanding for the meaning of access control in the CORBA security. We propose a formal model for access control the CORBA security using the formal description language, which is called Z language based on typed set theory. The proposed model provides concrete semantics of the access control function to both the system administrator and the implementor.