• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1C
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• pp.36-47
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• 2002

MGCP ia standard protocol by IFTF, which is designed to facilitate inter-working with other protocols. Since the nature of protocol, it can be known as a proper solution to integrate heterogeneous networks consisted of various protocols and systems. In this paper MGCP is used for controlling VoIP gateways from external call control elements(MGCs) and introduces a method to improve interoperability for various MGC in a gateway based on MGCP. It presents implementation issues to provide the interoperability for MGC dependent parts such as call flows of message encoding, and a system architecture to resolve the issues.

• Journal of the Korean Society for Railway
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• v.15 no.5
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• pp.442-446
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• 2012

This paper is a practical study on the development of SEMP template using SE & SW infrastructures. SEMP, which is a management system for systems engineers, has been developed for the LRT(Light Rail Transit) industry and has been tailored to suit domestic conditions. SE & SW infrastructures were developed to assist in creating an effective and efficient SEMP for the industry of this study. This paper proposes a method to reduce costs, manpower, and time for the LRT industry using SEMP based on SE & SW infrastructures.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.89-96
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• 2002

In this paper, we present the functional architecture for the traffic engineering capable policy based network management system. In this paper, we also examine the traditional approach to network management, contrast it with the policy based approach. The architecture includes the traffic engineering facilities, especially MPLS traffic engineering functions, to provide maximum network resource utilization. The policy server should communicate with the traffic engineering server and network manager to enforce the network policy efficiently. The interfaces and interworking methods are described in this paper.

• Journal of KIISE:Databases
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• v.28 no.4
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• pp.620-632
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• 2001

This paper proposes a mediator system which can provide a view management function in the today's heterogeneous computing environment including operating system database management systems and other software. while most mediators use view modification mechanism only, the use of view materialization is also considered in this research. In order to optimize the management cost for materialized views the proposed method applies a decay factor for modeling the access behaviors of views In other words, the most recently access pattern gets the highest attention in the optimization process all the necessary it with the CORBA.

• Annual Conference of KIPS
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• 2015.04a
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• pp.205-206
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• 2015

스마트폰이 유선전화의 단말기가 되면 스마트폰의 전화번호부를 유선통화에도 사용할 수 있게 되어 유선전화의 사용량이 늘어나고, 이를 통해 사용자는 통신요금이 낮아지는 혜택을 누리며 유선 사업자는 수익 증대를 기대할 수 있다. 그러나 이동통신용 단말기로 제작된 스마트폰을 유선전화의 단말기로 이용하는 데는 i) 사용자 편의성 증대를 위한 스마트폰 등록 절차의 간소화, ii) 저전력 상태와 WiFi 비활성화 상태에서 전화수신 안정화, iii) 무선데이터 전송시간 변이에 의한 음성품질 저하 회피 등 다양한 기술적 문제들이 존재한다. 본 논문에서는 이와 같은 문제들에 대한 해결 방안을 제시하고 이를 반영한 실험용 시스템의 구현 결과를 보여준다. 실험용 시스템은 사설교환기 기능을 내장한 WiFi-AP, 안정적인 전화수신 알림을 위한 PUSH broker, VoIP 어플리케이션이 설치된 스마트폰으로 구성된다. 실험용 시스템은 PSTN 망과 VoIP 망에 연동하여 스마트폰으로 안정적인 통화품질을 제공할 수 있음을 보였다.

• Annual Conference of KIPS
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• 2004.05a
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• pp.977-980
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• 2004

SCORM은 웹 환경에 존재하는 다양한 학습관리시스템 간에 표준화 된 컨텐츠 모델을 제시함으로써 학습 컨텐츠의 호환성을 보장하고 재사용성을 높이고자 하는 표준이다. 하지만 기존의 SCORM 기반학습관리시스템은 학습 리소스의 공유를 위한 기반은 제공하지만 학습 컨텐츠의 세부적인 학습 내용과 학습 문맥을 표현하고, 이를 공유할 수 있는 방안은 제시해 주지 못한다.본 논문에서는 지식 관리 기술인 시맨틱 웹의 RDF를 사용하여 학습 메타데이터를 표현하고, 이를 통합 관리할 수 있는 학습 메타 데이터 관리 서비스를 기존 학습관리시스템과 연동될 수 있는 모듈로서 제안한다. 또한 SCO에 포함될 수 있는 RDF기반 특징정보 파일을 정의하고, 저장된 학습 메타데이터를 SOAP 프로토콜을 통하여 외부 학습관리시스템과 공유할 수 있는 방안을 제시한다.이를 기반으로 교수자는 학습 주제와 관련된 컨텐츠를 검색하여 새로운 학습 컨텐츠를 제작 할 수 있으며, 학습자는 의미 기반 검색을 통하여 다양한 학습 컨텐츠와 능동적인 학습 환경을 체험 할 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.503-514
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• 2019

This paper proposes a blockchain-based urban service-operation model that can enhance usability by integrating several data-driven services operated in a city. In the proposed model, in order to encourage the participation of service users, the providers of data and values that can be consumed and utilized by each service acquire incentives, and consumers can use various services by paying the incentives. In this way, the proposed service model provides a structure in which various services can be interworked within the incentive system. The characteristics of blockchain technology can also guarantee service operation and management transparency. In addition, in this paper, by establishing and operating a prototype, the efficiency and operability of the proposed model are verified. As a result, three implemented data-driven urban management services are organically inter-compatible based on the concept of the proposed integrated incentive system. In the future, the proposed service model can be applied as an elemental technology of urban operational and management architectures based on citizen participation using local currency, and by cooperating with local economic revitalization projects of interest to many local governments. It is expected that the expansion of the blockchain technology area will also be possible through convergence with smart city services.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.7
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• pp.205-214
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• 2021

For smart manufacturing, most semiconductor sites utilize automated material handling systems(AMHS). As one of the AMHSs, the OHT control system(OCS) manages overhead hoist transports(OHT) that move along rails installed on the ceiling. This paper proposes a real-time scheduling system to efficiently allocate and control the OHTs in semiconductor logistics processes. The proposed system, as an independent subsystem within the OCS, is interconnected with the main subsystem of the OCS, so that it can be easily modified without the effect of other systems. To develop the system, we first identify the functional requirements of the semiconductor logistics process and classify several types of control scenarios of the OHTs. Next, based on SEMI(Semiconductor Equipment and Materials International) standard, we design sequence diagrams and interface messages between the subsystems. The developed system is interoperated with the OCS main subsystem and the database in real time and performs two major roles: 1) OHT dispatching and 2) pathfinding. Six integrated tests were carried out to verify the functions of the developed system. The system was normally operated on six basic scenarios and two exception scenarios and we proved that it is suitable for the mission planning of the OHTs.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.883-892
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• 2009

SOAP using WSDL(Web Service Definition Language) was proposed for effective integration of distributed objects. But the SOAP message and WSDL document automatically generated from development tool are fully dependent on the development environments. So the dependency of SOAP messages and WSDL documents for objects to the development environment is still a big problem to be solved for the integration of heterogeneous distributed objects. In order to support integration of heterogeneous distributed object, we implemented SOAP Bridge called WBSB(WSDL Based SOAP Bridge). As service request message for a particular service object is translated into appropriate SOAP message for the selected service object by WBSB using WSDL repository, a client can use service object without considering the development environment of the service object.

• Annual Conference of KIPS
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• 2003.05b
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• pp.1209-1212
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• 2003

오늘날 인터넷 환경에서의 망은 유무선의 환경이 통합된 하나의 망으로 달수 있다. 일반적인 TCP에서는 무선망에서의 핸드오프나 비트오류 등으로 인한 패킷 손실이 발생하는 경우에도 흔잡제어 알고리즘으로 손실된 패킷을 복구하게 되며 이러한 복구는 혼잡윈도우를 줄이게 됨으로 인해 현저히 TCP의 처리량을 감소시키게 된다. 본 논문에서는 유무선이 통합된 망에서 데이터 전송 효율을 높일 수 있는 알고리즘을 제시하고자 한다. 이 알고리즘에서는 홈서버를 사용하여 무선망에서 발생한 패킷 손실이 종단간의 재전송이 아닌 홈서버에서 지역 재전송을 함으로써 유무선망의 부하를 줄이고 흔잡제어 알고리즘이 실행되는 것을 방지하여 TCP의 성능향상을 가져올 수 있으며 캐쉬메모리에 재전송 패킷을 보관하여 재전송함으로써 보다 빠른 재전송효과를 얻을 수 있다.