• Journal of Advanced Navigation Technology
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• v.24 no.6
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• pp.593-600
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• 2020

The equipment for marine IoT service have to overcome the effect of seawater. Furthermore, the free floating transmitter in seawater will be less affected by the seawater environment. The results of the design and fabrication of antenna, which is embedded in buoy, are shown in this research. The proposed antenna is used to supervise the states of fishing gears in monitoring system for real-name system of electric fishing gear. The selected frequency band of the proposed antenna is 920 MHz, and PCB pattern type is selected for subminiature and light weight. It is confirmed that RF characteristics is more degraded, however, the radiation is gradually upward as the contact surface of buoy with seawater is more broaden through the simulation results. That is, the RF performance of the proposed antenna is more deteriorated but beam radiation characteristics is more suited the marine IoT, the seawater effect is more increased. It is expected that the proposed antenna will contribute the implementation of IoT network based on low power wide area (LPWA) when the degradation of RF performance will be settled.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.437-443
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• 2019

Aid to navigation is a navigational aid facility that informs a sailing vessel of its location and direction as well as a location of a specific obstacle by means of a light, shape, color, sound, radio wave, etc. It can be valuable in improving the safety of day and night vessel navigation at sea. For the safety of the tug boat, the minimum equipment requirements for each type of tug boat are arranged. Despite these preparations, the collision accidents between tug boats, barges, and light buoys can occur when the tug boat turns due to the length of the tow-line, tidal current, and the barge's momentum etc. The purpose of this study was to propose the basic system that analyzes the physical relationship between two vessels regarding the tug boat-barge-light buoy dynamics and propagate the corresponding data through the aid to navigation management & operation systems in use at each regional oceans and fisheries.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.628-636
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• 2018

Because large buoys are mainly made of steel, they are heavy and vulnerable to corrosion by sea water. This makes buoy installation and maintenance difficult. Moreover, vessel collision accidents with buoys and damage to vessels due to the material of buoys (e.g., steel) are reported every year. Recently, light buoys adopting eco-friendly and lightweight materials have come into the spotlight in order to solve the previously-mentioned problems. In Korea, a new lightweight buoy with a 7-Nautical Mile lantern adopting expanded polypropylene (EPP) and aluminum to create a buoyant body and tower structure, respectively, was developed in 2017. When these light buoys are operated in the ocean, the visibility and angle of light from the lantern installed on the light buoys changes, which may cause them to function improperly. Therefore, research on the performance of light buoys is needed since the weight distribution and motion characteristics of these new buoys differ from conventional models. In this study, stability estimation and motion analyses for newly-developed buoys under various environmental conditions considering a mooring line were carried out using ANSYS AQWA. Numerical simulations for the estimation of wind and current loads were performed using commercial CFD software, Siemens STAR-CCM+, to increase the accuracy of motion analysis. By comparing the estimated maximum significant motions of the light buoys, it was found that waves and currents were more influential in the motion of the buoys. And, the estimated motions of the buoys became larger as the sea state became worser, which might be the reason that the peak frequencies of the wave spectra got closer to those of the buoys.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.136-138
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• 2013

Current, standards light buoys as maritime traffic safety facilities have 10 different types of buoys and the smallest size of those is 4.4m. Therefore, making for easy replacement and repair parts for the type of small light buoys is proposed. Meanwhile, position reliability of floaters by external forces in the environment fall and stability examination should be considered for prohibiting accidents as loss. In this paper, a new light buoy is analyzed on Encounter Frequency types using commercial program and fluid forces is simulated on cross-sectional shape of the float using two-dimensional Boundary Element Method(BEM).

• Journal of Navigation and Port Research
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• v.29 no.2
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• pp.119-126
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• 2005

Ferry Golden Jindo collided with Ferry Princess near the No.7 light buoy of Incheon Port No.1 Passage in restricted visibility due to dense fog. The result was that Ferry Golden Jindo got a hole at the starboard midship section shell plating and Ferry Princess sustained damages at the starboard bow and 25 persons injured The aim of this paper is to investigate this collision accident, to clarify its causes, and to prevent such accident from occurring again In short, this collision resulted from Princess' high speed in restricted visibility, Golden Jindo's carelessness of watchkeeping, lack of proper safety training of crew, lack of instruction of supervisor, carelessness af PTMS Center and indifference of Korea Shipping Association, etc.

• Journal of Navigation and Port Research
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• v.47 no.3
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• pp.128-133
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• 2023

In order for Aids to Navigation to provide sustainable services to users, it is possible when there is no Aids to Navigation accident. If an Aids to Navigation accident occurs, the manager should efficiently manage it to prevent the same accident. However, the current Aids to Navigation accident management only specifies the cause and type of the accident. There are no separate guidelines. Thus, the accident is recorded differently depending on the manager. Therefore, this study attempted to redefine Aids to Navigation accident. To this end, Aids to Navigation accidents that have occurred over the past 23 years (year 2000 to years 2022), IALA's Aids to Navigation information standard, S-201, and categories of accidents (traffic accidents and marine accidents) were analyzed. Causes of Aids to Navigation accidents were divided into internal and external causes. Accidents were divided into three types: Light tower accident, buoy accident, and equipment accident. By further subdividing primary items, the cause of accident was reestablished into 7 items such as mooring and bad weather and 11 items such as Light tower damage, buoy loss, and equipment breakdown. These research results can be used as basic data to provide future Aids to Navigation accident statistics.

• Journal of Ship and Ocean Technology
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• v.10 no.4
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• pp.34-48
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• 2006

The visual observation of wave condition depends on the observer's skill and experience. Also, the environmental conditions such as light and cloud heavily influence the visual measurement. In the speed test of sea trial, the wave measurement should be objective and accurate. In this paper, the problems of visual measurement and their effects on speed test are described. To overcome those problems, we developed the wave measurement system using commercial marine X-band radar, WaveFinder. The system installed at inland base was calibrated by waverider buoy and then the system's operability was defined. Onboard tests had also been performed three times for formal wave measurement to correct the ship speed. The results illustrated very good agreement with visual observation by experts. It can be concluded that the system would be useful to measure wave and swell information for the sea trial, irrespective of day and night.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.3
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• pp.72-81
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• 2022

Positions of five drifting buoys deployed on August 2020 near southwestern area of Jeju Island and numerically predicted velocities were used to develop five Artificial Intelligence-based models (AI models) for the prediction of particle tracks. Five AI models consisted of three machine learning models (Extra Trees, LightGBM, and Support Vector Machine) and two deep learning models (DNN and RBFN). To evaluate the prediction accuracy for six models, the predicted positions from five AI models and one numerical model were compared with the observed positions from five drifting buoys. Three skills (MAE, RMSE, and NCLS) for the five buoys and their averaged values were calculated. DNN model showed the best prediction accuracy in MAE, RMSE, and NCLS.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.430-436
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• 2019

It is needed to develop an antenna with features of subminiature, light weight and multi-band operation for the variaty services in maritime and industrial fields. The PCB pattern antenna is one of the appropreiate antennas solving these requirements. In this research, the design and fabrication of the PCB pattern antenna operating on the single band of 920 MHz are investigated. The final goal is that the development of the dual band PCB pattern antenna operating on 260 MHz and 920 MHz, which is based on the proposed antenna. It is evident that the performance in the frequencies of 902 MHz, 915 MHz and 928 MHz among of 920 MHz ISM band is better than that in other frequencies. It is also confirmed that the differences of the voltage standing wave ratio, return loss, gain and efficiency between three frequencies are less than 5%. It is expected that the development of communication link of 5-10 km is possible when the induced results are applied into the low power wide area (LPWA) network desinged by the rule of -30 dB sensitivity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.243-246
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• 2016

Data transfer technique is one of the key elements of the IT infrastructure, in accordance with each environment and function, using some kind of protocol. Using the three protocols such as WCDMA, AIS, and TRS at sea IT industry. so It uses three protocols saw has a problem that the operation of each protocol-specific server. so server maintenance costs increase and sea Device Manager has been placed in a situation which operates to develop each of the protocol-specific analysis program. The reason of the protocol is divided into three, marine equipment (lighthouses, buoys, light buoy) manufacturing companies and the date of manufacture, such as, communication environment (distance, communication speed) because such is wrong all, trying to unify this and enormous cost and time is a situation that can not be the exchange occurred when. So in the Ministry of Maritime Affairs and Fisheries, the number of frequency of use is low, communication performance is seeking to refrain from Kure each local organizations and companies the use of low TRS protocol. his paper is intended to conduct research on the basis of the actual data to analyze whether the method is how economical to store a single DB by analyzing other types of protocols. This reduces the shortage of marine IT industry, even a little, shall helps reduce administrative costs.