• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.209-216
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• 2015

It is difficult to detect, track and intercept ballistic missile because of its high speed and short flight time from launching to target area. In order to increase the success rate of a ballistic missile interceptor, it is important to track the flight trajectory for a long time after the detection in the early launch. Radar Cross Section(RCS) of the target is important when the target to be detected by the radar, and the difference between the RCS value greatly changes depending on the viewing direction during the flight missile trajectory. In this paper, it is assumed that a ballistic missile is launched at east coast of North Korea, observe that missile by a land based radar and sea deployed radar. And it is analyzed and compared that RCS difference of ballistic missile.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.465-473
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• 2019

This paper is meaningful as the first case where a 4 - sided hull-fixed phased array radar was installed on a mast separated from Korea and the alignment was verified. The mechanical alignment method was studied for accurately mounting two separate masts for naval ships and the 3D scanner for alignment. Hull-fixed phased array radar uses very high frequency, so the short wavelength can cause a phase difference of the device due to the small positional error. Since the array antenna is fixed with the hull, it has higher accuracy control than the rotary radar for 4 array surfaces. The study describes a method of checking the flatness of two radar masts manufactured at a factory, a method of aligning masts in a shipyard, and a method of aligning four array pad mounting surfaces. As a tool for this, a 3D laser scanner and a software-based method for comparing survey results with 3D CAD are used. This paper is meaningful as the first example of installing a four-sided hull-fixed phased array radar on a separate mast from a Korean naval ship and deriving a mechanical alignment method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.163-168
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• 2008

Ship detection from satellite remote sensing is a crucial application for global monitoring for the purpose of protecting the marine environment and ensuring marine security. It permits to monitor sea traffic including fisheries, and to associate ships with oil discharge. An automatic ship detection approach for RADARSAT Fine Synthetic Aperture Radar (SAR) image is described and assessed using in situ ship validation information collected during field experiments conducted on August 6, 2004. Ship detection algorithms developed here consist of five stages: calibration, land masking, prescreening, point positioning, and discrimination. The fine image was acquired of Ulsan Port, located in southeast Korea, and during the acquisition, wind speeds between 0 m/s and 0.4 m/s were reported. The detection approach is applied to anchoring ships in the anchorage area of the port and its results are compared with validation data based on Vessel Traffic Service (VTS) radar. Our analysis for anchoring ships, above 68 m in length (LOA), indicates a 100% ship detection rate for the RADARSAT single beam mode. It is shown that the ship detection performance of SAR for smaller ships like barge could be higher than the land-based radar. The proposed method is also applied to estimate the ship's dimensions of length and breadth from SAR radar cross section(RCS), but those values were comparatively higher than the actual sizes because of layover and shadow effects of SAR.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.57-59
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• 2011

선박 운항 안전을 위한 기술은 선박 자체 뿐만아니라 육상 해상교통관제 시스템(VTS)에서도 매우 중요한 역할을 수행한다. 최근 국제적으로 e-Navigation을 지향한 최신 IT기술을 반영한 새로운 안전운행을 지원하기 위한 VTS 기술개발이 활발하게 진행되고 있다. 이러한 국제적 변화와 더불어 최근 국내에서는 초고속 선박인, 위그선이 개발되어 곧 운항될 예정이므로, 기존의 VTS에서(>70NM) 추적할 수 있는 물표의 속도 범위를 벗어나고 있다. 따라서 물표 추적 및 융합 알고리즘의 위그선 환경을 고려한 개선된 기술개발 필요성이 제기되어 왔다. 본 연구에서는 이러한 초고속 선박 환경에서 국내 VTS 시스템에서 적용 가능한 방안을 연구하고, 이들을 비교하여 실제 적용할 수 있는 기술개발 방향을 정립하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.153-161
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• 2005

Recently, The government of Korea declared to develop RFID(Radio Frequency IDentification) as one of key strategic technology to perform U-Government using Ubiquitous technology. But, most of the related technologies for RFID are mainly focused on the inlaned application excepting marine applications. The last target of this study is to implement new Marine RFID(M-RFID) that can cover all of EEZ areas as large five times as inland volume. In this paper, as a basic study for the M-RFID, we carried out an establishing the concept design of M-RFID, developing the construction method of M-RFID and, extending the idea of M-RFID. As studying results, it is known that the M-RFID can be use in many practical areas such as the protection of EEZ area and aqua culture, the safety of fisher man, the disaster control for inlander and, fisheries ligistics with real-time.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.47-52
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• 2021

Recently, the share of wind power in energy markets has sharply increased with the active development of renewable energy internationally. In particular, large-scale wind farms are being developed far from the coast to make use of abundant wind resources and to reduce noise pollution. In addition to the electromagnetic interference (EMI) caused by offshore wind farms to coastal or air surveillance radars, it is necessary to investigate the EMI on global maritime distress and safety system (GMDSS) communications between ship and coastal stations. For this purpose, this study investigates whether the transmitted field of MF/HF band from a ship would be subject to interference or attenuation below the threshold at a coastal receiver. First, using geographic information system digital maps and 3D CAD models of wind turbines, the area of interest is electromagnetically modeled with patch models. Although high frequency analysis methods like Physical Optics are appropriate to analyze wide areas compared to its wavelength, the high frequency analysis method is first verified with an accurate low frequency analysis method by simplifying the surrounding area and turbines. As a result, the received wave power is almost the same regardless of whether the wind farms are located between ships and coastal stations. From this result, although wind turbines are large structures, the size is only a few wavelengths, so it does not interfere with the electric field of MF/HF distress communications.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.307-313
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• 2022

As the development of renewable energy expands internationally to cope with global warming and climate change, the share of wind power generation has been gradually increasing. Although wind farms can produce electric power for 24 h a day compared to solar power plants, Their interfere with the operation of nearby radars or communication equipment must be analyzed because large-scale wind power turbines are installed. This study analyzed whether a land radio station can receive sufficient signals when a ship sailing outside the offshore wind farm transmits distress signals on the VHF band. Based on the geographic information system digital map around the target area, wind turbine CAD model, and wind farm layout, the area of interest and wind farm were modeled to enable numerical analysis. Among the high frequency analysis techniques suitable for radio wave analysis in a wide area, a dedicated program applying physical optics (PO) and shooting and bouncing ray (SBR) techniques were used. Consequently, the land radio station could receive the electromagnetic field above the threshold of the VHF receiver when a ship outside the offshore wind farm transmitted a distress communication signal. When the line of sight between the ships and the land station are completely blocked, the strength of the received field decreases, but it is still above the threshold. Hence, although a wind farm is a huge complex, a land station can receive the electromagnetic field from the ship's VHF transmitter because the wave length of the VHF band is sufficiently long to have effects such as diffraction or reflection.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.487-489
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• 2012

최근 해상교통관제시스템(VTS : Vessel Traffic Service)은 항행지원정보교류가 가능한 육상국으로서 선박 통항의 안전과 효율성을 증진시키고 환경을 보호하는 e-Navigation의 핵심적 시스템으로 역할이 기대되고 있다. 최근 IALA를 통하여 국제적으로 데이터 공유를 위한 구조에 대한 연구와 표준 포맷이 정해지고 있으며 IVEF(IVEF:Inter-VTS Data Exchange Format)는 이중의 한 중요한 요소이다. 이러한 실시간의 트래픽 정보는 국가적으로 보안에 민감한 요소이나 현 규격에 정해진 보안성에 대한 규정은 다소 정해진 바 없이, 연동하기 위한 보안 규격을 다시 설계하여 상호 추진하고 연동시험을 수행해야 될 수준이다. 또한 Radar에 대한 물표 자체의 전달은 현재 고려하고 있지 않기 때문에 Track되지 않은 물표는 불필요한 많은 속성들을 같이 전송해야 하며, 레이더 물표에 대한 별도의 정해진 속성은 없는 상태여서 기존의 선박의 길이를 기반으로 비율을 고려하여 다시 재 산출되어야 가능하다. 따라서, 본 연구에서는 이러한 데이터 공유를 위한 IVEF의 규격을 검토하고 이를 보완하는 내용을 고려하여 새로운 프로토콜 및 방안을 제시한다. 이러한 구조는 VTS 시스템에서 적용 가능한 방안인지를 확인하여, 실제 적용할 수 있는 기술개발로서 방향을 정립하고자 한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.1 s.28
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• pp.61-67
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• 2007

This paper describes the implementation procedures and results of Fishery Safety and Security System to secure an aquaculture area from a thief. The system designed with various functional modules to implement selectively available system providing low cost to high cost and simple function to high function according to user's requirement in a practical fishing fields. In the abalone farm field located in Jin island, Jeonranam province and having condensed aquaculture facilities with 50 cages (10 row by 5 column) within 0.5 miles from coast, practical field tests are carried out. As results from that tests, it is found that the system can guard not only the whole area of cultivating farm field but also each cages with detail.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.209-213
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• 2005

The current AIS network and. system are run on a full scale with 22 ground stations and. 11 operational systems, completing a nation-wide, integrated network However, currently it needs to manage sea traffic by linking AIS to VIS which 1vs a limited service area due to restricted radar detection zones in harbors or coastal areas. Accordingly this study analyzes the current status of the AIS system and. proposes technological and. operational improvement plan of the current AIS system through investigating the actual conditions of the AIS system and. its operations.