• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.514-520
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• 2015

This paper presents a novel shore-to-sea maritime data transmission system based on time-code diversity, using visible light in maritime environments to overcome the limitations of conventional maritime wireless communications. The proposed system is primarily comprised of existing LED-based lighthouses and maritime transceivers (marine beacons, buoys, etc.), and thus is considered cost-effective in terms of implementation. We first analyze maritime visible-light communications on the basis of the unique properties of a maritime environment, i.e. sea states (wave height, wind speed, etc.), plus atmospheric turbulence, using the Pierson-Moskowitz (PM) and JONSWAP (JS) spectrum models. It is found that the JS model outperforms the PM model, and that the coverage distance depends on the LED power and sea states. To combat maritime fading conditions that significantly degrade performance and coverage distance, we propose a time-code diversity (TCD) scheme in which the delayed versions of the original data are retransmitted using orthogonal Walsh codes. This TCD scheme is found to be superior, in that it offers three orders of magnitude in terms of BER performance, compared to a conventional (non-TCD) transmission scheme. The proposed scheme is robust and efficient in overcoming the effect of impairments present in maritime environments with a BER of approximately $10^{-5}$and a data rate of 100 Kbps at a distance of 1 km.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.157-163
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• 2015

Recently, there has been much interest in the e-Navigation that applies a variety of digital devices to shipboard thanks to the high interest to maritime safety and the rapid development of ICT technologies. The e-Navigation proposes a new ICT paradigm in maritime information service and maritime safety. This study proposes the shore-based maritime information service platform that enables the converged services of various kinds of maritime data and the standard ENC based on IHO S-100. The proposed maritime information service platform enables the harmonized integration, presentation and web services of ENC, sensed data such as AIS, ocean weather and currents, and geospatial data. Also, the platform enables the mobile maritime information service through WebApp or App software operating in mobile devices of smart phone or web pad. Finally, the proposed platform accommodates the standard ENC of the existing S-57 and the new S-101, and the standard web services of WMS and WMTS of ISO 19100 and OGC.

• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.23-29
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• 2012

Korea has maritime jurisdiction over an area 4.5 times larger than the nation's inland area, but negotiations with surrounding nations on the maritime boundary delimitation have still not been completed satisfactorily. In particular, maritime boundary delimitation has become an important issue in terms of maritime security and resource exploration. Considering national interests, the delimitation of the maritime boundary is essential. However, no system to help the decision-makers involved in maritime boundary delimitation has yet been systematically constructed. Therefore, the aim of this study was the development of a system to support such decision-making. In this study, considerations related to maritime boundary delimitation were investigated through expert advice and international precedents. Based on these considerations, data were collected from several organizations, and a spatial database was systematically constructed. Finally, MBDSS (maritime boundary delimitation support system) was developed to support maritime boundary delimitation. This GIS-based system provides visual information about the considerations for the maritime boundary delimitation. Thus, it could help decision-makers to choose appropriate boundaries during the negotiation. Furthermore, this system is expected to be utilized as a scientific tool on the delimitation of maritime boundaries.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.166-175
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• 2006

Since many years ago and in spite of the existence of national regulations and international conventions ratified by the countries that are conformed the Central American Region (CAR), the seagoing maritime sector of this Region, has developed its activity without any type of safety measures. Therefore, a large number of people are known to die, disappear and suffer from serious injuries each year. These maritime casualties devastate the families affected by these events, and severely impact the local social and economic well-being. While all these accidents occurred in this Region, non government or any other official records are available recording these casualties Due to the lack of any historical written reports about maritime casualties occurred in this Region, the compilation of this type of accidents information and data was carried out directly by the researchers in the field. Also, all the information about the CAR Maritime Organization Components was too compiled by the authors from the respective National Maritimes Authorities. From the compiled information was elaborated the CAR maritime casualties data base and from the analysis of the above data base were determined the main causes of the maritime accidents occurred in the CAR. The lack of safety measures onboard and the ignorance of the presence and influence of atmospheric phenomena were among main factors that had been caused the maritime casualties in this Region. By other hand, from the analysis of the CAR maritime organization components, the existence of one level of organization very similar among them was determinate. The objective of this research was to analyze the role of the CAR maritime organization in the prevention of the occurrence of maritime casualties. The results of this study provides general understanding of the causes of this type of accidents in the CAR and basis for support in improving safety navigation system and measures so that the number of fatalities and maritime accidents may be reduced in the future.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.5
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• pp.379-384
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• 2013

For effective ship management in VTS(Vessel Traffic Service), it needs to assess the external force acting on ship. Big data in maritime traffic can be roughly categorized into two groups. One is the traffic information including ship's particulars. The other is the external force information e.g., wind, sea wave, tidal current. This paper proposes the method to assess the external force acting on ship using big data in maritime traffic. To approach Big data in maritime traffic, we propose the Waterway External Force Code(WEF code) which consist of wind, wave, tidal and current information, Speed Over the Water(SOW) of each ship, weather information. As a results, the external force acting a navigating ship is estimated.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1555-1558
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• 2011

국방 모델링 및 시뮬레이션(Modeling & Simulation) 소프트웨어 분야에서 분산 시뮬레이션 기술표준인 HLA(High Level Architecture)의 적용이 늘어나고 있으며, 시뮬레이션 요소의 재사용성 및 신뢰성 확보를 위한 개발 프레임워크 제공이 핵심기술로 떠오르고 있다. 특히, 시뮬레이션을 위한 공통 서비스를 제공하는 M&S 프레임워크가 개발되었다. 또한, 가상의 시험 환경을 제공하기 위한 요소 중 시험환경의 구성을 위한 시나리오 모델이 있다. 본 논문에서는 시험 환경을 구성하기 위한 M&S 프레임워크 내의 시나리오의 스키마 설계에 대해서 기술한다.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.4
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• pp.187-193
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• 2015

A maritime Differential Global Positioning System (DGPS) reference station broadcasts correction information to users having a DGPS receiver so that the navigation performance can be improved. A maritime DGPS reference station consists of a reference station (RS) that generates and broadcasts correction information, an integrity monitor (IM) that monitors the integrity of correction information, and a control station (CS) that controls them. A maritime DGPS reference station is continuously operated for 24 hours, and thus improvement in the ease of operation is a major element that can improve the performance of the system. In this study, a configuration of a maritime DGPS reference station that can improve the ease of operation and a relevant protocol were proposed, and an example of the implementation of the proposed system was presented.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.473-481
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• 2023

In this study, a simulation system was developed to verify autonomous navigation algorithm in complex maritime traffic areas. In particular, real-world maritime traffic scenario was applied by considering near real-time maritime traffic information provided by Korean e-Navigation service. For this, a navigation simulation system of Unmanned Surface Vehicle (USV) was integrated with an e-Navigation equipment, called Electronic Chart System (ECS). To verify autonomous navigation algorithm in the simulation system, initial conditions including initial position of an own ship and a set of paths for the ship to follow are assigned by an operator. Then, considering real-world maritime traffic information obtained from the service, the simulation is implemented in which the ship repeatedly travels by avoiding surrounding obstacles (e.g., approaching ships). In this paper, the developed simulation system and its application on verification of the autonomous navigation algorithm in complex maritime traffic areas are introduced.

• Journal of Navigation and Port Research
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• v.31 no.6
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• pp.497-502
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• 2007

The important purposes of research in ship operation are to ensure safe navigation, high efficiency of transportation, high accuracy, and security. IMO, develops a broad strategy for incorporating the use of new technologies in a structured way to ensure that their use is compliant with the various electronic navigational and communication technologies and services that are already available. As a base research for E-Navigation, therefore, this paper proposes a maritime information network based on Mesh Network that is one of the maritime broadband solutions. Firstly, this paper analyzes an international port network system and the requirements of port network for E-Navigation. Finally, it designs the maritime information network system based on Mesh Network and shows its validity for E-Navigation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.315-316
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• 2022

In order to reduce maritime accidents and promote maritime safety and the happiness of the sea people, the Ministry of Oceans and Fisheries has been providing Intelligent Maritime Traffic Information services to the public from the end of January 2021. Various information is generated and collected through this service, and research and development is underway to develop and verify a service algorithm by applying the collected information to data science to realize a safer and more efficient intelligent maritime traffic information service. In order to develop and implement this, a data pipeline system that connects the collected and stored data and can access, use, and store data from multiple systems smoothly is required. Therefore, in this study, a data pipeline that can be used in various systems such as a datascience based service algorithm development environment and an intelligent maritime transportation service test-bed was designed.