• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1350-1357
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• 2012

Korean NDGPS, which consists of the ocean-based reference station of 11 site and the land-based reference station of 6 sites, are operating. The land-based reference stations provide the output power of 500W, the service shadow regions are occurred due to mountains and nation topography. In this paper, the service coverages of land-based reference stations are analyzed in the viewpoint of output power enhancements of land-based reference stations within 1KW. Also, we suggest virtual land DGPS reference stations 2 sites to resolve the service shadow regions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.521-523
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• 2010

Reseatch and Analysis on the DGPS radiobeacon propagation measurement of Domestic ferry lines Starting with maritime DGPS Base stations of Palmido, Ochongdo which have been operated since 1999, truly our nation has become the most powerful country possessed with total of 17 DGNSS base stations in the field of DGNSS operation infrastructure. This paper intents to consider the development direction of the country's DGNSS services as identifying the services range of the maritime DGPS base stations in the south coast domestic ferry lines which sections are Busan$\rightarrow$Jeju, Jeju$\rightarrow$Nokdong.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.2 no.1
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• pp.43-50
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• 1990

This study is concerned with the optimization of steel jacket subjected to wave forces using the allowable stress design method. The optimization of member section is considered here. Objective function for the minmum cost design is obtained by considering the weight of steel jecket. Constraints are imposed to insure that structural displacement and strength are within allowable values. The nonliner otimization problems are solved by SUMT method including the modified Newton-Raphson method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.91-95
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• 2004

어업분야의 선진화를 위하여 해양수산분야의 현황파악 및 문제점 분석을 통한 어업정보화의 발전방향을 설정하고 다양한 정책을 효율적으로 추진하여 해양자원관리 및 활용성 제고를 통한 종합적이고 체계적인 정보화 기반을 조성해야 할 것이며, 이를 위해서는 어업통신의 정보화가 필수적일 것이다. 해상이동체인 어선들을 상대로 정보통신망을 구성하기 위한 통신수단에는 위성통신망이 있으나 장기적으로 사용시 막대한 통화료 부담이 있으므로 영세한 어업인들에게는 도입될 회망이 없다고 보아도 무방하며, 최적의 방안으로 기존의 SSB통신시스템을 이용하는 방법이 연구되고 있다. 운용비 부담이 없는 HF대 SSB통신에 의한 어업통신망을 구성하기 위해서는 육상의 해안국에서는 정보시스템 운영의 기본체계인 무선 송ㆍ수신소 구축 및 무선통신망 프로토콜에 의한 무선데이타 통신시스템이 갖추어져야 할 것이다. 그리고 어선에는 무선데이타 통신을 하기 위한 단말장치가 필수적이라 하겠다. 이에, 본 연구에서는 동 시스템에 CPS를 연동하여 이동하는 어선이 실시간에 자동으로 위치를 송출하고, 해상기상ㆍ엇가ㆍ해황 둥 각종 정보를 수집할 수 있는 어선용 단말기를 구현하기 위한 방안에 대하여 제안하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.82-89
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• 1999

미국의 전파항법정책(FRP Federal Radionavigation Plan)은 여전히 SA정책(미국방성에서 GPS 위성 궤도에 오차를 실어 전파발사를 하는 정책)을 유지하고 있고, P(Y)코드 접속에 의한 고정밀 위치정보 사용 역시 미군 및 NATO군 등 미 국방성에서 인가한 사용자에게만 허용되고 있는 관계로 그 외의 사용자는 3차원 고정밀 위치정보가 요구되는 항공기 이착륙 유도시스템, 해ㆍ육상 정밀 구조/탐색 및 육ㆍ해ㆍ공 특수목적 등에 군사용 P(Y)코드대신 DGPS를 사용하고 있다. 본 연구는 한반도 남해안 및 동해안 일부까지를 유효거리로 하고 있는 일본 Marine Radiobeaeon/DGPS 시스템에 대한 한반도 연근해에서의 위치정보 사용 가능성을 확인하기 위해 한반도 남해안에서 측정 가능한 일본 DGPS국을 선택 모델로 하여 DGPS Data 측정실험 및 위치정보 정밀도 분석을 하였다. 연구결과 군사용 P(Y) 코드수준의 정밀도를 유지하고 있어 곧 구축 예정인 한국형 DGPS 국가망과 함께 선택적으로 사용할 수 있음을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.65-71
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• 2000

This thesis is what accident in sea have been produced as lost themselves life and property about 500times at every years. Therefore this was induced to experiment on a national basis that the role of communication of ship is to move from lose themselves life and property

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.92-99
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• 2016

AIS(Automatic Identification System) is an vessel traffic management system which exchanges vessel data with other nearby ships, AIS base stations using VHF band. A domestic AIS base station is located along coast lines or island. So it is difficult to collect vessel data from the ocean. To solve this problem, we adopted AIS payload on the low earth orbit satellite. The AIS payload on the satellite is interfaced with OBC(On-Board Computer) via UART and the FSW(Satellite Flight Software) manages it. The FSW have to receive AIS command from ground station and forward to AIS payload. Similarly FSW have to receive response, OBP, OGP data from AIS payload and it is downlink to the ground station. So in this paper we describe the FSW design & implementation for AIS payload.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.153-158
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• 2007

The INMARSAT is able to long range maritime communications that can not use for expensive charge in non-SOLAS ship. Therefore, international discussion for the question that replacements use of MF/HF band for maritime distress and safety communications in maritime. HF data communications system may be effectively utilized for SOLAS ships as well as for the existing non-SOLAS vessels including the fishing boats, which navigate A2 and A3 sea areas. The HF data communications may have various functions such as e-mail services, broadcasting services of up-to-date information related to marine safety, position reporting services, polling services etc. However, the present HF e-mail communications protocols have a problem of increasing calling redundancy as the number of channels in operation increases. This paper new protocol and communication sequence proposed in this submission establishes a proper radio link automatically and adaptively by taking channel traffic into account.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.55-59
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• 2009

In a base on the MDGPS base station which has been operated since 1999; our country has completed the construction of six Land Base Stations to use of NDGPS in land from starting Mu-Ju base station in 2002 to Chun Cheon base station which is going to be operated on July 2009. Accordingly, with the exception of the Chun-Cheon base station because it is being built now, we will consider a better direction of improvement in service for land base station after surveying and analyzing on the signal characteristic of land base station.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.4
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• pp.176-181
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• 1997

A practical, easy-to-use data acquisition device has been developed for use in civil and envirionmental engineering applications. It uses the PC parallel port for the acquisition and data transfer and is simple enough to be setup and run in laboratory and field experiment conditions. The usual limitations of data storage capacity of several data loggers was solved by using PC resources. Also versatile programming capability using high level languages of the PC programming environment such as C and Visual Basic enables the data acquisition device to be configured as a general and practical data acquisition system. An example of effective uses of the device is. provided for the water environment measurement at the Bangwha bridge construction site. The in site. test proved the device to be practical in civil and environmental engineering applications.