• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.206-208
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• 2019

섬이 많은 우리나라에는 섬에 전력을 공급하기 위하여 섬과 육지 혹은 섬과 섬 사이를 연결하는 전력공급선이 송전선이 많이 설치되어 있다. 송전선에는 또 헬리콥터가 비행을 할 때 헬리콥터와 송전선과의 충돌을 방지하기 위하여 항공장해표시구가 부착되어 있다. 이들 송전선 밑에 항로가 있을 경우 그곳을 지나는 선박의 레이더에 송전선에 의한 거짓상이 나타나 항해자가 소형 선박의 영상을 식별하는 데 어려움이 야기되기도 한다. 이 논문에서는 송전선에 의한 레이더 상이 발생하는 이유와 그 대책을 제시하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.509-510
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• 2014

본 연구 개발에서는 육로가 아닌 바다에서의 해양 환경 상태와 어선의 운행 시 사고 영상을 저장 확인할 수 있는 소형 어선용 영상저장 및 환경 데이터 저장 Set-top Box를 개발하고자 한다. 소형어선들은 매우 필요하나 장비의 고가로 인하여 구축하기가 어려워 저가의 장비의 개발은 필수적이다. 이를 기반으로 현재 해양경찰에서 사용하고 있는 무선통신 방식과 접목하여 사고나 위험한 상황 시 해양경찰이나 관제센터로 영상 및 데이터를 전송하여 해양에서 얻을 수 있는 각종 해양 환경정보 및 각 선박들의 안전에도 기여하고자 한다.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.4
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• pp.86-92
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• 2002

The feasibility of counting number of small vessels and position in Korean waters using the panchromatic imageries derived from the IRS-1C was tested. The parameters for interpretation of satellite's imageries of small vessels were location(position), size, shape, shadow, tone, texture and pattern, height and depth, situation and association with other vessels. The position of small vessels in the sea without GCP(ground control point) was considered to be inclusive in the satellite imagery with 35 km semi-diameter, denoting rough geographical position of the vessel. The size of vessel was measured by length from stem to stern of the vessel, distinguished by following wave on the surface water. Offshore fishing vessels were separated from merchant ships by their length smaller than 100 m. The shape of vessels on panchromatic imagery of IRS-1C appeared just streamline. In case of clouds which were similar to the shape of small vessels, we were able to distinguish between vessel and cloud by shadow of cloud in the water surface. The tone of sea surface was dark black while small vessel appeared bright white. Small vessel was distinguished from the rough texture of the sea surface and the regular pattern of the waves with white capes when weather was not so good. The situation of the fishing activity was estimated by information of fishing method related to the fishing boat such as the pair trawl in the Yellow Sea.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1173-1183
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• 2023

Over the past 20 years, Korea's overall import and export cargo volume has increased at an average annual rate of approximately 5.3%. About 99% of the cargo is still being transported by sea. Due to recent increases in maritime cargo volume, congestion in maritime logistics has become challenging due to factors such as the COVID-19 pandemic and conflicts. Continuous monitoring of ports has become crucial. Various ground observation systems and Automatic Identification System (AIS) data have been utilized for monitoring ports and conducting numerous preliminary studies for the efficient operation of container terminals and cargo volume prediction. However, small and developing countries' ports face difficulties in monitoring due to environmental issues and aging infrastructure compared to large ports. Recently, with the increasing utility of artificial satellites, preliminary studies have been conducted using satellite imagery for continuous maritime cargo data collection and establishing ocean monitoring systems in vast and hard-to-reach areas. This study aims to visually detect ships docked at berths in the Busan New Port using high-resolution satellite imagery and quantitatively evaluate berth utilization rates. By utilizing high-resolution satellite imagery from Compact Advanced Satellite 500-1 (CAS500-1), Korea Multi-Purpose satellite-3 (KOMPSAT-3), PlanetScope, and Sentinel-2A, ships docked within the port berths were visually detected. The berth utilization rate was calculated using the total number of ships that could be docked at the berths. The results showed variations in berth utilization rates on June 2, 2022, with values of 0.67, 0.7, and 0.59, indicating fluctuations based on the time of satellite image capture. On June 3, 2022, the value remained at 0.7, signifying a consistent berth utilization rate despite changes in ship types. A higher berth utilization rate indicates active operations at the berth. This information can assist in basic planning for new ship operation schedules, as congested berths can lead to longer waiting times for ships in anchorages, potentially resulting in increased freight rates. The duration of operations at berths can vary from several hours to several days. The results of calculating changes in ships at berths based on differences in satellite image capture times, even with a time difference of 4 minutes and 49 seconds, demonstrated variations in ship presence. With short observation intervals and the utilization of high-resolution satellite imagery, continuous monitoring within ports can be achieved. Additionally, utilizing satellite imagery to monitor changes in ships at berths in minute increments could prove useful for small and developing country ports where harbor management is not well-established, offering valuable insights and solutions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.1-2
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• 2011

최근 많은 분야에 무인시스템이 도입되고 있다. 초기에는 산업분야에서 인간이 하기 힘들거나 위험한 작업을 대신하는 단순 반복적인 자동화기술이 대부분이었으나, 최근에는 전자통신 기술발달에 힘입어 무인자동차, 무인항공기, 무인잠수정, 무인선박 등이 연구 개발되고 있다. 본연구에서는 자율형 소형무인선을 개발하고자 하였으며, 이와 관련하여 인터넷기반의 무선통신제어, 동력 추진 조타 냉각시스템, GPS 영상 헤딩센서 등 센싱시스템, 자율운항을 위한 제어기설계, GUI 등을 연구하였다. 아울러, 해상실험을 통해 유효성을 검증하였다.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1463-1478
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• 2022

Maritime transport accounts for 99.7% of the exports and imports of the Republic of Korea; therefore, developing a vessel monitoring system for efficient operation is of significant interest. Several studies have focused on tracking and monitoring vessel movements based on automatic identification system (AIS) data; however, ships without AIS have limited monitoring and tracking ability. High-resolution optical satellite images can provide the missing layer of information in AIS-based monitoring systems because they can identify non-AIS vessels and small ships over a wide range. Therefore, it is necessary to investigate vessel monitoring and small vessel classification systems using high-resolution optical satellite images. This study examined the possibility of developing ship monitoring systems using Compact Advanced Satellite 500-1 (CAS500-1) satellite images by first training a deep learning model using satellite image data and then performing detection in other images. To determine the effectiveness of the proposed method, the learning data was acquired from ships in the Yellow Sea and its major ports, and the detection model was established using the You Only Look Once (YOLO) algorithm. The ship detection performance was evaluated for a domestic and an international port. The results obtained using the detection model in ships in the anchorage and berth areas were compared with the ship classification information obtained using AIS, and an accuracy of 85.5% and 70% was achieved using domestic and international classification models, respectively. The results indicate that high-resolution satellite images can be used in mooring ships for vessel monitoring. The developed approach can potentially be used in vessel tracking and monitoring systems at major ports around the world if the accuracy of the detection model is improved through continuous learning data construction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.134-135
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• 2009

선박에서 주로 채택되는 열교환기는 쉘튜브형과 판형열교환기로 분류된다. 이 연구에서는 소형쉘튜브형 열교환기의 설계에서 중요한 요소인 냉각튜브와 벽면과의 간격에 따른 유동특성을 입자영상유속계를 이용하여 계측하였다. 연구 결과 벽면과의 거리변화에 따른 임계간격비는 0.25전후로 추정되었으며 벽면효과에 따른 정량적 데이터를 확보하였다.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.327-338
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• 2018

The possibility of ship detection monitoring at operational level using KOMPSAT-5 Synthetic Aperture Radar (SAR) and Automatic Identification System (AIS) data is investigated. For the analysis, the KOMPSAT-5 SLC images, which are collected from the west coast of Shinjin port and the northern coast of Jeju port are used along with portable AIS data from near the coast. The ship detection algorithm based on HVAS (Human Visual Attention System) was applied, which has significant advantages in terms of detection speed and accuracy compared to the commonly used CFAR (Constant False Alarm Rate). As a result of the integrated analysis, the ship detection from KOMPSAT-5 and AIS were generally consistent except for small vessels. Some ships detected in KOMPSAT-5 but not in AIS are due to the data absence from AIS, while it is clearly visible in KOMPSAT-5. Meanwhile, SAR imagery also has some false alarms due to ship wakes, ghost effect, and DEM error (or satellite orbit error) during object masking in land. Improving the developed ship detection algorithm and collecting reliable AIS data will contribute for building wide integrated surveillance system of marine territory at operational level.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.141-144
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• 2004

Aids to Navigation have been operated and placed along coasts and navigable waters as guides to mark safe water and to assist mariners in determining their position in relation to land and hidden dangers, controled on the basis of the maine traffic survey. The traditional survey have been conducted by some methods like an ocular observation using portable radar, a on-the-spot survey, a questionnaire. But these methods must have a lot of manpower and expenses. In this paper, we have developed the module which have some real time processing functions like making a database of radar image using PC camera, saving of the vessel's track, analysis if the maine traffic tendency and the distribution of density.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.61-62
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• 2002

본 연구는 전보에서 개발한 RTX에 대한 응용 연구의 하나로써 레이더 영상 신호의 수록 및 해석에 부가하여 타선의 GPS 위치정보를 수신하여 자선의 전자해도(ENC) 및 radar 화면상에서 동시에 표시함으로써 이들 두 선박의 간격을 측정할 수 있는 선간거리계, 또한, 타선의 ARPA radar가 탐지한 영상신호, 타선의 기동정보(own ship data, OSD) 및 추적표적의 정보(tracked target message, TTM) 등을 자선의 레이더나 전자해도 화면상에서 실시간으로 모니터링하는 software를 개발하고, 이들의 레이더 정보를 필요에 따라 hard disk에 수록 및 재생할 수 있는 아주 간편하면서도 범용성이 있는 레이더 정보수록 및 해석 시스템을 개발하였다. (중략)