• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.87-88
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• 2012

The IHO developed the S-100 standard for Digital Hydrographic Data in order to assist the proper and efficient use of hydrographic data and information for the safety of navigation and the protection of marine environment. The former model, S-57, was considered outdated to be utilized as the basis for the next-generation Electronic Chart(ENC) product specification. The key feature of the S-100 standard is the use of Registry and its components, Registers. This online-based Registry provides a universal standard that can be implemented in the actual performance of the navigation system with convenience. In the current situation, the only registry is owned by the IHO and it is available to domain experts. However, since S-100 is an international standard operated by an international organization, the process of the changes and updates of the data requires time before immediate implementation when demanded. Therefore, regarding the safety of navigation of the domestic users and mariners, a separate domestic registry is necessary to develop a domestic Information Registry. This study specifically aims to build a Registry based on IHO published S-99 through designing an adequate website dedicated for its purpose to provide collection of definitions and hydrographic data.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.313-320
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• 2022

The light buoy installed on the sea is always flexible, because it is affected by the weather as well as passing vessels. The position of the light buoy can be cached through the AtoN AIS (Automatic Identification System) and RTU (Remote Terminal Unit). This study analyzed the position data of the light buoys for the last five years (2017-2021), as well as the distribution of the light buoys within the maximum separated position. As a result, there was a basic error of 17.9% in the position data. Additionally, the separated position error of 197 light buoys to be analyzed was 70.64%, and the AtoN RTU was worse than the AtoN AIS by equipment. On the other hand, as a result of the plotting the position data of the light buoy, it was classified into four types. The most common percussion center type, the percussion center dichotomous type in which the position is divided into two zones based on the chimney, the central movement type with a fluctuating center, and the drag type, in which the position is deviated from the center for a certain period. Except for Type-1, the type was determined according to the position at which the light buoy was installed. This study is the first to analyze the position data of the light buoy, and it is expected that it will contribute to the improvement of the quality of the position data of the light buoy.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.231-238
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• 2023

The position of a light buoy is always flexible due to the influence of external forces such as tides and wind. The position can be checked through AIS (Automatic Identification System) or RTU (Remote Terminal Unit) for AtoN. As a result of analyzing the position data for the last five years (2017-2021) of a light buoy, the average position error was 15.4%. It is necessary to detect position error data and obtain refined position data to prevent navigation safety accidents and management. This study aimed to detect position error data and obtain refined position data by DBSCAN Clustering position data obtained through AIS or RTU for AtoN. For this purpose, 21 position data of Gunsan Port No. 1 light buoy where RTU was installed among western waters with the most position errors were DBSCAN clustered using Python library. The minPts required for DBSCAN Clustering applied the value commonly used for two-dimensional data. Epsilon was calculated and its value was applied using the k-NN (nearest neighbor) algorithm. As a result of DBSCAN Clustering, position error data that did not satisfy minPts and epsilon were detected and refined position data were acquired. This study can be used as asic data for obtaining reliable position data of a light buoy installed with AIS or RTU for AtoN. It is expected to be of great help in preventing navigation safety accidents.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.381-388
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• 2015

Global Maritime Distress and Safety System (GMDSS) equipment and Electronic Chart Display & Information System (ECDIS) are typical equipment which help seafarers to obtain information for ship's safe navigation. In this study, a survey on using of GMDSS equipment and ECDIS was conducted on a total of 260 ship masters and crew who have been working on ocean-going vessels. The subjects were asked about the usage, and level and reason of satisfaction or dissatisfaction of GMDSS equipment and ECDIS, the leading navigational system from which they receive information. The survey showed that the third- and fourth-most frequently used equipment, MF/HF and INMARSAT (telex), were deemed to be the second- and third-most useless equipment. It means that the frequency of device usage is not proportionate to the level of navigational safety. Especially, 'ease of device use (42.3%)' and 'necessity of the provided information (50%)' were highlighted as factors increasing the level of satisfaction with the system. The survey result shows that ship safety cannot be realized by only adopting advanced systems, technology and services. It emphasizes the need to consider the level of 'accessibility and appropriateness of the information' and 'ease of device use'. Discussions implemented by the IMO on various policies and regulations are aimed at securing ship safety. In order to achieve the goal, such institutions should be validated by end-users and relevant studies should be conducted.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.5
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• pp.754-763
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• 2018

The maritime ICT-convergence equipment are essentially required to a type approval (TA) certification that needs environmental and functional tests, to install in vessel. The environmental test is to experiment the possession for required durabilities of the target device in maritime environment, and the functional test is to check the required functions of target equipment based on international standard. In Korea, the environmental testing facilities amount to 227 sites, but there is no functional testing facility. Because of this, we establish a function test facility for the maritime ICT-equipment. In this paper, we analyze and design the functional testing requirement and required interlocking simulators for digital interfaces and navigation communication equipment. We propose the 2-steps of functional testing procedures, which are single test and integration test, to improve the reliability of testing result. The single test is to examine own functions of the target device, and the integration test is to check harmonized operation with other navigation and communication devices.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.14-15
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• 2019

Pilotage & Tugs Assistance Service in Korean e-Navigation provides port monitoring which presents features of port by utilizing dynamic and static information of vessel, weather data, water way information and etc. It also supports process related to pilotage and tugs according to each user types. This study suggests how this services can be utilized after practicalization and describes expectation from applying this utilization. The Pilotage & Tugs Assistance Service is expected to be platform for Pilotage & Tug by further research and development.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.344-352
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• 2019

A coupled analysis was performed between the riser to develop oil and gas in ultra-deepwater and the moored floating body. In general, the safety of the riser is conservatively evaluated by considering the maximum offset excluding the coupled analysis with the floating body. In this study, the safety of the riser was analyzed by considering the coupled motion analysis of the moored floating body. The riser is considered steel lazy wave riser (SLWR) applied in the deep sea, and the floating body is determined to FPSO. The methodology was presented on coupled and uncoupled analysis. The coupled effects were analyzed according to the incident wave headings in intact and damaged conditions of mooring lines. The tension of mooring lines, the motion of the floating body, and riser responses were analyzed according to the loading conditions.

• International Journal of Ocean System Engineering
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• v.1 no.2
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• pp.60-67
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• 2011

This paper presents an in-situ correction method to compensate for the position error of an autonomous underwater vehicle (AUV) near the sea floor. AUVs generally have an inertial navigation system assisted with auxiliary navigational sensors. Since the inertial navigation system shows drift in position without the bottom reflection of a Doppler velocity log, external acoustic positioning systems, such as an ultra short baseline (USBL), are needed to set the position without surfacing the AUV. The main concept of the correction method is as follows: when the AUV arrives near the sea floor, the vehicle moves around horizontally in a circular mode, while the USBL transceiver installed on a surface vessel measures the AUV's position. After acquiring one data set, a least-square curve fitting method is adopted to find the center of the AUV's circular motion, which is transferred to the AUV via an acoustic telemetry modem (ATM). The proposed method is robust for the outlier of USBL, and it is independent of the time delay for the data transfer of the USBL position with the ATM. The proposed method also reduces the intrinsic position error of the USBL, and is applicable to the in-situ calibration as well as the initialization of the AUVs' position. Monte Carlo simulation was conducted to verify the effectiveness of the method.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.6
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• pp.423-431
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• 2022

In this paper, the results of Planar Motion Mechanism (PMM) test for a 1/15 scaled model of the MARIN Joubert BB2 submarine is dealt with to derive the maneuvering coefficients for surface condition. For the depth of surface navigation, the top of the sail was exposed 0.46 m above the water surface in the model scale, and it corresponds to 6.9 m in the full scale. The resistance and self-propulsion tests were conducted, and the model's self-propulsion point was obtained for 1.328 m/s, which corresponded to 10 knots in the full scale. The maneuvering tests were performed at the model's self-propulsion point, and the maneuvering coefficients were obtained. Based on the maneuvering coefficients, a turning simulation was performed for starboard 30 degree of stern fins. The straight-line stability and control effectiveness in the horizontal plane were analyzed using the maneuvering coefficients and compared with the appropriate range. For the analysis of the neutral fin angle of the X-type stern fin, the stern fin test with drift angles was carried out. As a result, the flow straightening effect at lower and upper parts of the stern fin was discussed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.89-90
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• 2021

Undersea bases built in the deep sea are built in more extreme environments than in space. In addition, it requires the convergence of mechanics, electronics, shipbuilding, meteorology, and diving science, marine physics, chemistry, biology, and geology. Undersea base can be constructed through the fusion of various technologies. The development of extreme technology for undersea construction will be the most advanced technology in each field, and it will be applied to space and other fields, so it will be an opportunity to preempt the latest technology.