• Journal of the Korea Safety Management & Science
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• v.21 no.3
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• pp.23-27
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• 2019

The first aim of the study is to improve the productivity by uniformizing the thickness of coating and reducing quality-inspection time. The second aim is to cut down on the raw materials for coating by prevent the waste of spraying in the air during a painting process through a real-time coating-size-recognition monitering to fit the target components. To achieve the two aims, a simplified version of automatic coating control system for recognition of coating for vessels and Spray. With the sytem, following effects are expected: First, quality improvement will be achieved by uniformizing the film-thickness. Second, it will reduce the waste of coating paint by constructing the speed of the coating, the spray gun robot transfer time, and the number of DBs according to the size of the vessel. Third, as a 3D industry, it will be able to solve the difficulty of supply of labors and save up the labor costs. Therefore, in the future, further research will be needed to be applied to various products with DB design that designates the variable value, which is added for each type of pieces by comparing the difference between various types of workpieces and linear ones.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.601-606
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• 2019

The lenticular Location Based System is related to a location information technology. The system enables users to inform their location in real time wherever in a room, a building, a ship, a basement. In this paper, we analyze limitations and problems of the existing indoor Positioning System and propose a method of user-oriented location service. The proposed method consists of a lenticular sticker, a database(DB) acquisition and analysis technology. The proposed system can be used as an infrastructure to implement various indoor location-based services. In addition to improve user centered positioning accuracy through the development of location-based systems using indoor lenticular systems, it can be used in a disaster situation.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.629-636
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• 2022

We present a preprocessing method for an underwater target detection model based on a convolutional neural network. The acoustic characteristics of the ship show ambiguous expression due to the strong signal power of the low frequency. To solve this problem, we combine feature preprocessing methods with various feature scaling methods and spectrogram methods. Define a simple convolutional neural network model and train it to measure preprocessing performance. Through experiment, we found that the combination of log Mel-spectrogram and standardization and robust scaling methods gave the best classification performance.

• Journal of Sensor Science and Technology
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• v.33 no.5
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• pp.391-398
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• 2024

Accurate positioning is essential for unmanned underwater vehicle (UUV) operations, particularly for long-term survey missions. To reduce the inherent positioning errors from the inertial navigation systems of UUVs, or dead reckoning, underwater terrain observations from sonar sensors are typically exploited. Within the framework of pose-graph optimization, we can generate submaps of the seafloor and use them to add loop-closure constraints to the pose graph by determining the best match between the submaps. However, this approach results in error accumulation in long-term operations because the quality of local submaps depends on the dead reckoning. Hence, we can adopt external acoustic positioning systems, such as an ultrashort baseline (USBL), to add global constraints to the existing pose graph. We assume that the acoustic transponder is installed on a UUV and that the acoustic transceiver is equipped in an unmanned surface vehicle trailing the UUV to maintain an acoustic connection between the vehicles. We simulate the terrain and USBL measurements as well as evaluate the performance of the UUV's pose estimation via online pose-graph optimization.

• Journal of Korea Port Economic Association
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• v.34 no.4
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• pp.141-160
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• 2018

In this paper, to analyze the perception and response strategy of Korean ship owners on Global Sulphur Cap 2020, examined the IMO environmental regulation status focusing on MARPOL Annex VI regulation about air pollution prevention, technological measures to reduce SOx emission, shipping industry and management status of Korean ship owners. First of all, the questionnaire was conducted for Korean ship owners after selecting the evaluation factors. The purpose of this study was to investigate the difference of the perception and response strategy of Korean ship owners by corporation size and main vessel type using frequency and cross analysis. It is confirmed that various researches on SOx emission reduction have been carried out from various points of view at home and abroad. In this study, existing studies related to technical factors for regulatory response and economics analysis were examined and evaluation factors were selected. As a result of analysis, it is found that large-sized shipping companies are more prepared for regulatory response than small and medium-sized bulk carrier owners. There were similar perception and the direction of response strategy about the impacts by corporation size and main vessel type. In about two years to be implemented in 2020, It is necessary to find an appropriate response strategy based on the support policy of the government and related organizations and the systematic analysis of the ship owners. Through this study, although the difference between the perception and response strategy of the ship owners by corporation size and main vessel type was understood, it was found that there were limitations on specific response strategy and corporate data collection. In future research, we should overcome the limitations of this study and conduct an in-depth study.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.193-198
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• 2015

This research was conducted to provide an improvement plan concerning medical treatment on board and medical health care conditions for seafarers. 139 persons from government agencies and seafarer related organizations, who could influence the government's seafarers healthcare policy-making, were asked to fill in the questionnaire prepared for this research about their perceptive views on actual condition of health and disease management for seafarers. The results of the survey on seafarer's health care management conditions(p<0.01), health care manage ability(p<0.01), current radio emergency medical service policy(p<0.01), usefulness of on board medicine chest and medical equipment(p<0.05), and the system of the onboard medical care persons show the difference of perception level among the seafarer related organizations. But generally, the rate of negative responses was high. And this research suggests that there is an urgent need to provide portable health measurement equipment on board, reenforce regular medical examination and establish the seafarer's health promotion center for telemedicine and healthcare management(p<0.01) in order to improve the onboard medical treatment support system for healthcare of seafarers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.5
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• pp.511-518
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• 2019

This study aimed to extract the priority safety improvement factors for coastal passenger ships and analyze the perception gap between groups. To extract the improvement factors, we formed an expert group with maritime safety supervisors, passenger-ship safety inspectors (PSIs), and captains of passenger ships, and then conducted a Delphi survey. We found, using a hierarchy process, that the improvement factors were divided into three factors in Level 1 and ten factors in Level 2. For the relative importance analysis using the AHP (Analytic Hierarchy Process) model, we also formed two groups: an inspector group with maritime safety supervisors and PSIs, and an examinee group with safety managers, captains, and crews. Consequently, the factors of designation of public transportation for passenger ships and supporting the welfare of the crew were evaluated as the most important among the extracted factors. We conducted a t-test for the analysis of the perception gap between the two groups. Three perception gaps were found: increasing the inspection personnel, strengthening the qualification of the inspection personnel, and expanding the safety operation center. The result of this study will be useful for improving the safety policy of coastal passenger ships.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.403-408
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• 2015

A text-based communication system has been developed with a communication function on AIS and display and input function on ECDIS as a way to complement voice communication. It features no linguistic error and is not affected by VHF restrictions on use and noise. The text communication system is designed to use messages for clear intentions and further improves convenience of users by using various UI through software. It works without additional hardware installation and modification and can transmit a sentence by selecting only via Message Banner Interface without keyboard input and furthermore has a advantage to enhance processing speed through its own message coding and decoding. It is determined as the most useful alternative to reduce language limitations and recognition errors of the user and solve the problem of various voice communications on VHF. In addition, it will help to prevent collisions between ships with decrease in VHF use, accurate communication and request of cooperation based on text at heavy traffic areas.

• 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.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.16-16
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• 2018

2017년 겨울, 기록적인 한파로 인해 바다가 얼면서 인천 앞바다로 유빙이 유입되었다. 2013년 해상에서 유빙이 발견된 이후 약 5년만에 다시 유빙이 등장한 것이다. 중부청 소속 항공단 순찰결과에 따르면, 2018년 1월 12일 인천대교 인근 해상에서 최초로 발견된 이후 강화 연안, 영종도 북단 등 해상에서 광범위하고 불규칙한 형태로 유빙이 분포되어 있는 것으로 나타났다. 유빙의 문제점은 해상에서 선박의 안전운항을 저해하고 경비함정의 안전에 지장을 초래하며 기름 유출 시, 유출유의 거동 특성이 달라져 일반적인 방제방법의 적용이 곤란한 점이다. 이에 따라 해상에서의 해양오염사고 대응방안 마련을 위해 저온 및 유빙 유입 해상에서 유출유의 거동 특성을 알아보았다. 구분인자를 극한의 추위(Extreme Cold), 유빙(Pack Ice), 정착빙(Fast Ice) 3가지로 분류하여 기름의 성상변화 및 시사점을 살펴보고, 유출된 기름의 효율적 방제를 크게 3가지로 분류(기계적 봉쇄 및 회수, 화학적 분산제의 사용, 현장소각)하였다. 일반적인 방제장비를 저온 및 얼음분포 해상에서 사용 시 슬러시화 된 얼음으로 인해 유출유 회수가 어렵고, 동결온도에서 장비가 오작동할 우려가 있다. 이미 북유럽 국가에서는 극한의 추위와 얼음분포 해상에 특화된 방제장비를 도입하여 해양오염대비 대응을 하고 있다. 2003년 3월 발틱해에서 불법적으로 유출한 선저폐수를 특화 장비는 brush bucket 유회수기 이용 방제조치한 사례가 있으며, 2006년 5월 같은 장소에서 선박 침몰로 인한 기름 유출이 발생했을때도 brush bucket 유회수기 이용 방제조치를 하였다. 국내에도 이상 기후로 인해 기록적인 한파가 지속되면서 북극에서나 볼 법한 유빙들이 발견되고, 해양오염사고는 언제 어디서나 발생할 수 있으므로, 해양오염방제의 임무를 맡고 있는 국가기관으로써 특수한 환경까지도 고려하여 대응방안을 마련할 필요가 있다. 해양오염이 재난으로 인식되고 있는 상황에서, 그리고 지구온난화로 인한 이상기후변화가 지속되는 상황에서 겨울철 유빙 유입은 점점 더 많아질 수 있다. 본 연구에서는 자료나 방제경험이 부족하므로 일찌감치 북극항로 개발로 앞선 방제기술과 경험을 가지고 있는 북극이사회를 벤치마킹하여 관할 해역 특성에 맞는 대응방안을 고찰해 본다.