• Proceedings of the Korea Society for Industrial Systems Conference
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• 1997.11a
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• pp.417-433
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• 1997

A real-time operating system has focused primary on techniques to minimize processing time, with a secondary emphasis on system reliability issues. Conversely, fault-tolerant system has concentrated on using recourse and information redundancy to maximize the availability and reliability of the system, with a lesser emphasis on performance. We have developed a fault-tolerant and real-time operations system which support a powerful concurrent runtime environment under the above requirements. In this paper, we present an overview of real-time systems, design and implementation of a duplex architecture using advanced concepts and technologies such as fast " fault detection", "fault isolation" and "fault recovery" Because the duplex architecture has two dentical hardware elements and has several recovery steps and hierarchy to facilitate a fast recovery which must be proceeded by a prompt fault detection and isolation. Thus it makes possible to minimize the overhead of the systems including hardware and software and guarantee the service continuity of he systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.7
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• pp.1448-1458
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• 1997

In this paper the reverse link of the GLOBALSTAR-the representative CDMA LEO satellite system and LEO mobile satellite channel are developed by the SPW software simulation tool. And the performance of the system is evaluated. GLOBALSTAR is designed to give cellular-type service to hand-held user terminals through a constellation of 48 LEO satellites in circular orbites with 1414 Km altitude. Since LEO mobile satellite system communicates with mobile unit, it is suffered from severe multipath fading and shadowing. The fast mobility of LEO satellites makes the channel condition time vering. So, the LEO mobile satellite channel is different from land mobile channels. In this unique LEO satellite channel, it is shown that the performance of the GLOBALSTAR reverse link is varied according to the elevational angle, but this variation is overcome by satellite path diversity.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.123-126
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• 2015

This paper described fault tolerance system running on distributed multimedia. We implemented the error manager service so that the users participated in distribute multimedia collaborative work may refer synchronized error objects as the same view to others. distributed multimedia environment are based on IP-USN(Internet Protocol - Ubiquitous Sensor Network) and M2M(Machine to machine). This is a system that is suitable for detecting, sharing and recovering software error in distribute multimedia CSCW(Computer Supportes Cooperated Work) environment. With error synchronization system, a group cooperating users can synchronize error applications.

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.267-275
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• 2007

In this paper, we designed and implemented DCS terminal remote monitoring middleware for real-time auditor and management terminal status signal with relay and fuse status at power management room. The middleware consist of four component as event analyzer, event manager, service manager and user interface. We expected economic effects extend relay life-time that pre-detected errors and prevented relay fault.

• 한국디지털정책학회:학술대회논문집
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• 2005.11a
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• pp.299-311
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• 2005

This article introduces developing trends of an "Ubiquitous Interface" as an access method for use of various network resources, such as public wireless networks and un-licensed wireless networks in ubiquitous sensor network environments, without troublesome settings or operations by users. "Ubiquitous Interface" is include a relatively wide sense meaning not only physical interface of specified device or between processors, but anything method for access USN. These "Ubiquitous Interface" able to provide seamless services that adapt autonomously to the user's movements and changes in the state of wireless resources. Recently, strongly recommended candidates are RFID, NFC, Multi-mode mobile terminal, Wearable computer and OSGi for integrated digital home networking system as a future ubiquitous interface. These candidates are have to have flexibility and multiple physical communication channel for seamless service hand over and serve easy connection at huge USN to user. And, must have flexible software structure and multi-functional middleware. Consequently, for more enhance performance of an ubiquitous interface and developing, need more structured and integrated future plan.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.123-126
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• 2012

본 논문에서는 최근 주목을 받고 있는 클라우드 컴퓨팅 시스템 중 구글 앱스를 초등학교 현장에 어떻게 활용할 수 있는지 그 방안에 대해 모색해 보았다. 구글 앱스는 구글의 다양한 클라우드 컴퓨팅 서비스 중 SaaS(Software as a Service)에 해당하는 것으로써 캘린더, 메일, 문서도구, 사진, 사이트 도구, 유튜브, 지도 등의 서비스를 제공하는 것이다. 구글 앱스에서는 구글의 동일한 아이디 하나로 모든 서비스에 로그인이 가능하며 웹상에서 작업한 내용은 모두 웹에 저장되므로 언제 어디서나 네트워크에 연결된 디바이스만 있다면 활용이 가능하다. 그 뿐 아니라, 스마트폰, 태블릿 PC가 확산되고 있고 가격이 낮아짐에 따라 학생들도 활용하게 된 지금, 구글 앱스는 모바일 디바이스에도 서비스를 최적화시켰기에 학생들의 접근성이 더욱 높다. 앞으로 온라인 교육 등도 포함되면 적어도 국내에서는 교육계에 파급력이 상당하리라 생각하며 교육분야에 본격적으로 클라우드 컴퓨팅이 도입되기를 기대한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.209-210
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• 2018

본 논문에서는 IIoT 환경에서 효율적인 긴급 데이터 패킷 처리를 위한 스케쥴링 방식을 제안한다. 이는 weighted round robin 스케쥴링에 기반하고, 비선점형 시스템에 적용하는 방식으로 처리한다. 긴급 데이터의 평균 큐 사이즈에 따라 적응형으로 중요도를 조절함으로써 최적화시킨다. 이는 적은 패킷 손실률과 작은 딜레이로 이어진다. 이 적응형 스케쥴링 방식은 갑작스런 처리량의 변화에 많은 패킷 손실률과 딜레이 증가량 없이 대처하는 것에 효율적인 해결책이 될 것으로 기대된다.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.427-428
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• 2012

건설사업의 복합화, 대형화, 첨단화에 따라 3차원 설계와 정보모델 작성에 필수적인 BIM(Building Information Modeling) 소프트 웨어 활용을 확대하고 도입과 운용비용을 절감할 수 있도록 클라우드 컴퓨팅 환경의 서비스형 소프트웨어 방식의 개발방안을 제안한다.

• Journal of the Korean Society for information Management
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• v.1 no.1
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• pp.162-175
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• 1984

Efficient information flow is the lifeblood of any business. So, Ssangyong research center designed computerized systems to provide computer-based services and name it STIS-I. But the service system is for the retrieval of document written in Alpha-Numeric letters So, the interal technical information written in Korean letters are neglected. But the failing to make use of this literature can result in costly duplication of research. Here are introduced the retrieval system of the internal technical information (STIS-II) by COHIRES (Conversational Hangeul Information Retrival System) which was put into operation 1983. Also the functions of the COHIRES are described.

• 한국IT서비스학회:학술대회논문집
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• 2007.11a
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• pp.386-391
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• 2007

개방형 서비스개발자들은 SCE(service Creation Environment) 도구를 사용하여 망에 대한 전문적인 지식이 없더라도 예전보다 쉽고 빠르게 서비스를 개발할 수 있게 되었다. 본 논문에서는 툴킷 라이브러리 형태의 SCE를 제공하는 방법을 제안한다. SCE 툴킷 라이브러리는 SCE를 SDK((Software Development Kit) 형태로 제공한다. 이는 기존의 IDE(Integrated Development Environment) 환경에 라이브러리 형식으로 SCE 기능을 추가할 수 있게 함으로써, 개발자가 기존에 사용하던 친숙한 환경에서 서비스를 개발할 수 있도록 해준다. 또한 Parlay X API, 웹 2.0 API, 유틸리티 API를 제공하는데 있어서 복잡한 API 및 파라미터를 추상화하여 제공하는 방법을 제안한다. 이러한 SCE 툴킷 라이브러리는 창조적인 새로운 서비스의 출현에 많은 기여를 할 것으로 전망된다.