• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.214-220
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• 2024

Remote control is used for operating maritime autonomous surface ships. The operator controls the ship using control data generated by the remote control system. To ensure successful remote control, three principles must be followed: safety, reliability, and availability. To achieve this, the suitability of both the control data and operators for remote control must be established. Currently, there are no international regulations in place for evaluating remote control suitability through experiments on actual ships. Conducting such experiments is dangerous, costly, and time-consuming. The goal of this study is to develop a suitability evaluation method using the output values of control devices used in actual ship operation. The proposed method involves evaluating the suitability of data by analyzing the output values and evaluating the suitability of operators by examining their tracking of these output values. The experiment was conducted using a shore-based remote control system to operate the training ship 'Hannara' of Korea National Maritime and Ocean University. The experiment involved an iterative process of obtaining the operator's tracking value for the output value of the ship's control devices and transmitting and receiving tracking data between the ship and the shore. The evaluation results showed that the transmission and reception performance of control data was suitable for remote operation. However, the operator's tracking performance revealed a need for further education and training. Therefore, the proposed evaluation method can be applied to assess the suitability and analyze both the control data and the operator's compliance with the three principles of remote control.

• 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.

• Journal of Ocean Engineering and Technology
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• v.32 no.2
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• pp.143-150
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• 2018

In this study, we designed and developed an underwater LED communication system composed of an LED and a photo sensor. In addition, we experimented with video data transmission in a water tank. Two communication modules were installed in the 3 m water tank, and the image data transmission test was successfully performed at a rate of 20 frames per second(FPS), image resolution of $480{\times}272$, and data communication speed of 4 Mbps.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.139-145
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• 2004

It is well known that human errors is involved in most of maritime accidents. For the purpose of reducing the influence of human elements on maritime activities, it is necessary to identify the human unsafe acts in those activities. The commonly used methods in identification of human unsafe acts are maritime accident statistics or case analysis. With the statistics data, people could roughly identify what kinds of unsafe acts or human errors have played active role in the accident, however, they often neglected some active unsafe acts while overestimated some mini-unsafe acts because of the inherent shortcoming of the methods. There should be some more accurate approaches for human error identification in maritime accidents. In this paper, the application of technique called grey relational analysis (GRA) into the identification of human unsafe acts is presented. GRA is used to examine the extent of connections between two digits by applying the, methodology of departing and scattering measurement to actual distance measurement. Based on the statistics data of maritime accidents occurred in Chinese waters in last 10years, the relationship between the happening times of maritime accidents and that of unsafe acts are established with GRA. In accordance with the value of grey relational grade, the identified main human unsafe acts involved in maritime accidents are ranked in following orders: improper lookout, improper use of radar and equivalent equipment, error of judgment, act not in time, improper communication, improper shiphandling, use of unsafe speed, violating the rule and ignorance of good seamanship. The result shows that GRA is an effective and practical technique in improving the accuracy of human unsafe acts identification.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.6
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• pp.1659-1674
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• 2024

Conventional maritime communication struggles to provide high data rate services for Internet of Things (IoT) devices due to the variability of maritime environments, making it challenging to ensure consistent connectivity for onboard sensors and devices. To resolve this, we perform mathematical modeling of the maritime channel and compare it with real measurement data. Through the modeled channel, we verify the received beam gain at buoys on the ocean surface. Additionally, leveraging the modeled wave motions, we estimate future angles of the buoy to use the Extended Kalman Filter (EKF) for design beamforming strategies that adapt to the evolving maritime environment over time. We further validate the effectiveness of these strategies by assessing the results from an outage probability perspective. focuses on improving maritime communication by developing a dynamic model of the maritime channel and implementing a Kalman filter-based buoy motion tracking system. This system is designed to enable precise beamforming, a technique used to direct communication signals more accurately. By improving beamforming, the aim is to enhance the quality of communication links, even in challenging maritime conditions like rough seas and varying sea states. In our simulations that consider realistic wave motions, you've observed significant improvements in link quality due to the enhanced beamforming technique. These improvements are particularly notable in environments with high sea states, where communication challenges are typically more pronounced. The progress made in this area is not just a technical achievement; it has broad implications for the future of maritime communication technologies. This paper promises to revolutionize the way we approach communication in maritime environments, paving the way for more reliable and efficient information exchange on the seas.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.319-320
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• 2005

This paper describes the principles and structures of an expert system for arrester diagnosis. The expert system analyzes and decides the arrester condition by total leakage current, its harmonic component, and temperature because the deterioration of arresters appeared in an increase of leakage current and surface temperature of it. Additionally, influence of system voltage harmonics and ambient temperatures on leakage current changes were considered in the design. The expert system is consisted of a data acquisition module and a computer for monitoring. The acquired analog data are digitalized and transmitted to the computer by an optical link which is free from interference.

• Annual Conference on Human and Language Technology
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• 2013.10a
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• pp.126-128
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• 2013

빅데이터(Big Data)는 현재 생산되고 있는 데이터 중 그 규모가 방대하고, 생성 주기가 짧으며, 수치 데이터 뿐 아니라 텍스트 이외의 멀티미디어 등 비정형화된 데이터를 포함하는 대규모 데이터를 말한다. 빅데이터를 처리하여 가치 있는 정보를 추출하는 방법에 관한 연구가 활발하게 진행되고 있으며, 이를 바탕으로 빅데이터가 다양한 분야에서 활용되고 있다. 현재 국내 주식시장에서도 빅데이터를 이용하여 기업의 투자에 활용하고 있다. 이 논문에서는 인터넷의 증권과 관련된 뉴스를 수집하여 수집된 뉴스와 주가 지수를 이용하여 기업 뉴스 평가 시스템을 개발하는 방법을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.774-781
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• 2004

The HF band SSB communication of coast radio station had operated with principal axis of maritime communication until early in the 1990. But, that is changed with development of data communication and satellite technique, which have operated a few by rapidly decrement of user with accomplishment of the CMDSS. Recently, the radio system of HF band is expanded to globe maritime communication, which is support to maritime safety information and data traffic service by low charge with the SSB high speed modem. This study have proposed the digitalize method for maritime communication system using HF band in domestic.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.116-122
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• 2004

The HF band communication of roast radio station had operated with principal axis of maritime communication until early in the 1990. But, that is changed with development of data communication and satellite technique, which have operated a few by rapidly decrement of user with accomplishment of the GMDSS. Recently, the radio system of 11u band is expanded to globe maritime communication, which is support to maritime safety information and data traffic service by low charge with the SSB high speed modem. This study have proposed the digitalize method for maritime communication system using HF band in domestic.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.114-116
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• 2014

The interpolation of the missing AIS dynamic data can be used for predicting the lost data of the ship's state which is able to product the valuable information for analyzing and investigating the maritime accidents. The previous research proposed some interpolating methods however there exists some problem, firstly, the interpolated parameters such as COG, SOG, HDG weren't described sufficiently and accurately as in AIS message, secondly, each method is only suitable to some kinds of given AIS data, finally at heavy wind and current area, the parameters of AIS dynamic change quickly in short time, therefore, the modelling of the variation of ship's dynamic based on the physical characteristic is very difficult, in these cases the time-series and numerical method are usually better. This research proposes the other method through numerical analysis which can be suitable for many different kinds of the lost data, parameters are interpolated sufficiently, beside that this model is appropriate to all variation in short time interval. All the given AIS dynamic are regarded as the functions to time, then curves are established for fitting all data. Experiments are carried out to evaluate the performance of this approach, the interpolation results show this approach can be applied well in practice.