• 한국통신학회논문지
• /
• 제21권3호
• /
• pp.643-651
• /
• 1996

본 논문에서는 서비스 노드에 집중된 제어기능을 활용하여 다양한 멀티미디어 서비스 제공에 대한 가능성을 검증하기 위해 공동작업에 관한 기능 구현에 중점을 두었다. 기본적인 공동작업 기능 확인을 위한 상위 응용으로써 텔레라이팅을 그 대상으로 하였으며 이를 위하여 기존의 서비스노드 에뮬레이터에 공동작업 기능을 부가하는 한편 윈도우즈 환경에서 동작되는 공동작업을 위한 서비스노드용 단말을 구현하여 실험모델을 구성하였다. 이에 대한 기능을 시험함으로써 공동작업과 관련된 기분 기능들이 원활히 수행됨을 확인하였으며, 결국 서비스노드의 개념이 다양한 형태의 멀티미디어 회의형 서비스를 지원할 수 있음을 제시하였다.

• 한국통신학회논문지
• /
• 제27권12C호
• /
• pp.1228-1237
• /
• 2002

통신망 운용관리 시스템의 기능은 크게 구성, 성능, 장애, 과금 및 보안관리로 나뉘어 진다. 이 중에서 구성관리기능은 통신망의 구성정보를 수집하여 사용자 혹은 다른 관리 기능에 제공하는 기반 관리 기능이다. 본 논문에서는 이러한 구성관리 기능을 CORBA (Common Object Request Broker) 분산환경 하에서 구축하는 방안을 제시한다. 본 논문에서 제안하는 계층적 구성관리 시스템은 프로토콜 계층별로 관리객체가 설계 및 구현되어 다양한 데이터링크 계층 전송 기술들을 통합 관리할 수 있다. 또한 분산 MIB/MIT를 통해 다른 관리 기능 모듈과 효율적으로 연동할 수 있으며 확장성이 뛰어나다.

• Journal of Communications and Networks
• /
• 제4권4호
• /
• pp.336-343
• /
• 2002

A major challenge for next generation mobile communication is capturing the system architecture’s complexity with all its internal and external dependencies. Seamless integration of heterogeneous environments in all system parts is a key requirement. Moreover, future systems have to consider the different evolution cycles of individual system parts. Among those, services are expected to change the fastest. With respect to these considerations, we propose an overall architecture for next generation mobile communication systems. It covers all system parts from wireless transmission to applications including network and middleware platform. Our approach focuses on adaptability in terms of recon- figurability and programmability to support unanticipated system evolution. Therefore, we consider abstraction layers which consist of adaptable cooperating components grouped by open platforms rather than rigid system layers. In addition to that, we introduce cross-layer cooperation allowing an efficient use of the available resources. Specific scenarios illustrate the feasibility of our approach.

• 한국통신학회논문지
• /
• 제32권8A호
• /
• pp.802-812
• /
• 2007

Mobile IPv6환경에서 고속 핸드오버 프로토콜은 핸드오버 지연 시간을 줄임으로써 끊김 없는 서비스가 가능하도록 해준다. 이러한 고속 핸드오버의 이점을 IEEE 802.16e 환경에 적용하고자 본 논문은 다중 동시 바인딩 기법과 IEEE 802.21에서 제안된 이종망간의 핸드오버 기법을 이용한 IEEE 802.16e 기반 MIPv6망에서의 고속 핸드오버 기법을 제안한다. 또한 수학적 분석을 통해 기존의 FMIPv6와 핸드오버 지연과 패킷 손실량을 비교 분석한다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 C
• /
• pp.1255-1257
• /
• 1997

In order to obtain key technologies for a kW class internal humidifying proton-exchange-membrane fuel cell (PEMFC) a single cell with a large electrode area has been designed and manufactured and the performance of large area membrane/electrode assemblies (MEAs) has been evaluated by using the single cell. A small area MEA made of commercial E-TEK electrode and Nafion 117 membrane showed a performance of 0.7V, $300mA/cm^2$ whereas large area MEA made of catalyst layer on carbon support and Nafion 117 showed a lower performance. To improve the performance of large MEA direct coating of catalyst was carried out on the membrane using a screen printer.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 C
• /
• pp.1308-1310
• /
• 1997

Several methods for electrode fabrication of phosphoric acid fuel cell(PAFC) have been studied. The conventional methods that include a coating method and a rolling method, have disadvantages of a very complicated drying process and a hot pressing process for making a large electrode. In this study, to solve these problems, the mixing method of coating and rolling processes has been developed. In the mixing method, the electrode was coated on the electrode support and, after drying the coated layer, was rolled at room temperature and then sintered at $350^{\circ}C$. The single cell performances of the electrodes fabricated by several methods were examined and the mixing method appeared a good cell performance of 0.65 V, $260\;mA/cm^2$. Also the single cell with an area of $2000\;cm^2$ was manufactured and its performance attained 0.593 V, 300 A.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.1542-1549
• /
• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• Nuclear Engineering and Technology
• /
• 제46권2호
• /
• pp.125-146
• /
• 2014

This review aims to provide a synthesis of the knowledge generated and the lessons learned in roughly 15 years of UMo dispersion fuel R&D in Europe through a series of irradiation experiments. A lot of irradiations were also performed outside of Europe, particularly in the USA, Russia, Canada, Korea and Argentina. In addition, a large number of out-of-pile investigations were done throughout the world, providing support to the understanding of the phenomena governing the UMo behaviour in pile. However, the focus of this article will be on the irradiations and Post-Irradiation Examination (PIE) results obtained in European experiments. The introduction of the article provides a historic overview of the evolution and progress in the high density UMo dispersion fuel development. The ensuing sections then provide further details on the various phases of the development, from the UMo dispersion in a pure Al matrix through the addition of Si to the matrix to address the interaction layer formation and finally to the more advanced solutions to the excessive swelling encountered in various experiments. This review was based only on published results or results that are currently in the process of being published.

• Ocean and Polar Research
• /
• 제32권3호
• /
• pp.267-268
• /
• 2010

Many countries has been interested in studying the East Sea to look ahead into the world oceans' future, since the East Sea has been known as a miniature ocean. In this respect, PICES decided the East Asian Seas Time-series (EAST) studies, and the East Sea as the first subject (EAST-I). Since 2006 Ministry of Land, Transport & Maritime Affairs, Korea has supported the Korean EAST-I program. Through the Korean EAST-I program, 44 research papers were published in various scientific journals. This special issue contains 6 research articles including results from the interdisciplinary observation in the summer, 2008. Those articles cover the entire East Sea from the Korea Strait to the Japan Basin, and also cover the studies of the euphotic layer to the bottom sediment. MLTM and KIMST have provided full support to EAST-I program. KHOA carried out the joint cruises in the Ulleung Basin. Those are deeply appreciated. Finally, we would like to express our gratitude to the editorial board of Ocean & Polar Research.

• 한국콘텐츠학회논문지
• /
• 제6권11호
• /
• pp.126-134
• /
• 2006

기존의 객체지향 통합 모델링 방법은 전쟁게임 모델을 두 계층으로 구분하여 개발할 수 있는데, 상위계층에서는 객체의 추상화된 행위를 모델링하며 하위계층에서는 모델의 세부적인 행위를 표현하게 된다. 이 방법에서는 시뮬레이션 전문가와 군 관련 전문가가 각각의 계층에서 별도로 작업을 할 수 있는 장점이 있다. 본 논문에서는 통합 모델링을 발전시킨 파라미터 행위 모델링 방법을 이용하여 전쟁 게임 시뮬레이터를 구축할 수 있는 방안을 제시한다. 제안한 방법에서는 군 관련 전문가 또는 사용자가 모델링 방법에 대하여 별도의 지식이 없이도 새로운 알고리즘이나 전략을 시뮬레이터에 추가하거나 수정할 수 있는 장점이 있다. 제안한 방법의 효용성을 보이기 위해 구현된 해군 군함의 전쟁게임 시뮬레이터를 구체적으로 소개한다.