• Journal of Navigation and Port Research
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• v.37 no.5
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• pp.447-452
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• 2013

Vessel traffic system uses multiple sea surveillance radars as a primary sensor to obtain maritime traffic information like as ship's position, speed, course. The systematic errors such as the range bias and the azimuth bias of the two-dimensional radar system can significantly degrade the accuracy of the radar image and target tracking information. Therefore, the systematic errors of the radar system should be corrected precisely in order to provide the accurate target information in the vessel traffic system. In this paper, it is proposed that the method compensates the range bias and the azimuth bias using AtoN information installed at VTS coverage. The radar measurement residual error model is derived from the standard error model of two-dimensional radar measurements and the position information of AtoN, and then the linear Kalman filter is designed for estimation of the systematic errors of the radar system. The proposed method is validated via Monte-Carlo runs. Also, the convergence characteristics of the designed filter and the accuracy of the systematic error estimates according to the number of AtoN information are analyzed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.613-620
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• 2011

In order to perform scientific evaluation of dredge results, it is needed to construct the system which is able to manage and evaluate the work process by monitoring in real-time the dredge process such as dredge ship position, dredge depth and dredge volume. This research aims to develop the hydrographic dredge surveying system adding water depth measurement method to both precise positioning and navigation methods using GPS, which allows a high rate of measurement and long distances between the control point and dredging points, operate in all weather conditions, and does not require line of sight to points. We constructed Beacon DGPS-based hydrographic dredger guidance and position management system and developed the operation program which makes the dredge operation perform as monitoring work situation in real-time. It is expected that this developed system will be able to contributes to reducing ultimately the cost in hydrographic dredging or hydrographic construction industries.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.331-335
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• 2016

When a boating accident, such as a January number three, the customer's risk management issues emerged. Ships and accident risk in confined spaces such as risk management to locate the customer and dangers of probation is available. In this paper, aboard after consent to obtain information for customers to wrist to customers, webbing or portable device embedded in devices and Wireless sensor information Input was attached, disposable consumer information. Customer on board the ship setting for location analysis and positioning according to information communication protocol, ships, each customer's real-time location information on the screen, 3 the foundation of d customers on the floor Can be designed to inform. Threshold designed to reduce the error of the information to analyze the position in current position and errors. Also, to system attacks would control the situation of accident and emergency jaenanguk server with real-time information transmission of information outside the emergency during a disaster, search and Disaster relief to be possible.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.221-226
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• 2002

To provide reliable data for drift prediction models, field experiments were carried out in the coastal region off Busan port. Four different size of vessels(10, 30, 50, 90G/T ton) were deployed for the experiment. Among them G/T 50ton class vessel was equipped with instruments measuring the currents, winds, headings and trajectory data. In the rest of vessels only the position data were recorded for the purpose of target divergence study. The trajectories of each vessel were measured by DGPS(Differential Global Positioning System) and collected by APRS(Automatic Position Reporting System). The experiment was done in wind of 2~10m/s and current of 0.5~1.5m/s. The leeway was derived by subtracting surface current velocity from target drifting velocity. The leeway rate of G/T 50ton vessel was found to be about 3.6% and the computed leeway speed equation was $U_L$=0.042 W - 0.034. The processed leeway angle data were deflected by $-30^{\circ}$~$40^{\circ}$ from the direction of ship drift.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2001.10a
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• pp.19-25
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• 2001

At present the identification of vessels is still depending on the OOW (Officer Of Wateh) in VTS (Vessel Traffic Service), which is completed by radar, and also by the combination of VHF radio and VHF direction finder. However, with the development of port transportation and economic, this conventional way of identification can't satisfy more and more request for the information that the VTS needs from the vessels. In such a case, the AIS(Automatic Identification System) precept which is based on STDMA (Self-organized Time Division Multiple Access) technique is put forward by IMO (International Maritime Organization). AIS can automatically provide the information, including own ship's identification, type, position, course, speed, and other information to the appropriately equipped coast station and other ships. At the same time it can also automatically monitor and track the nearby ships similarly fitted with AIS. On the basis of describing the whole comprising and the format of transmission information of AIS, this paper mainly studies the key communication techniques in AIS, such as STDMA protocol, net synchronization and GMSK(Gaussian Minimum Shift Keying)technique, and so on. At last this paper briefly introduces the recommendation decided by IMO on forcing the sea-going ships to fixed with AIS equipments, and it continuos with the unexploited potential of AIS if it applies in VTS.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.110-111
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• 2010

Recently, container terminal managers make an experiment on the double cycle and dual cycle operation, which ship loading and unloading were carried out simultaneously, for increasing the productivity of quay side. However, if we make an experiment on dual cycle operation in a real job site, the efficiency is poor up to terminal operation method as YTs(Yard Tractors)' allocation method, QCs(Quay Cranes)' working speed, and position of export containers. So, this paper examine more efficient terminal operation method, when terminal uses dual cycle operation.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.813-817
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• 2003

By increasing trades between countries, importance of harbors is becoming serious, including our country. When it comes to Container Crane Operation, the most important matter is how many containers are loaded in a truck or a ship by given time. This can be a crucial matter of harbors in taking care of materials. The present harbors' crane uses a wire-rope conveyance materials are transported in the air and have high free-angle of location. The sway can cause the delay of time, wrong position of Trolley and the damage of materials. In this study, we obtain the optimal PID parameters with GA(Genetic Algorithm) and apply those parameters to the PID Controller. In the result of the experimentation, we can see how effectively the PID controller, applied with the optimal parameters obtained by GA, can control the sway angle.

• Journal of Advanced Marine Engineering and Technology
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• v.5 no.1
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• pp.12-19
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• 1981

As the fuel oil cost covers from 45% to 60% of the total expenditure for fishing boat operation, the energy saving is now an urgent problem to be taken a countermeasure for engineers, manufacturers or specialists engaging in this field. Undertaking a second-hand engine of the trainging ship, the author made several reconstructions to restore its performances. By inserting foot linears of connecting rods the compression ratio was increased and by adjusting both the fuel injection timing and the cooling water outlet temperature, its thermal efficiency was improved. The results of the experimental operation were summarized as follows. 1. By raising the piston top position 0.75mm more than the value of the operating manual, the compression pressure increased 1.3 kg/$cm^2$ and the maximum pressure did 3.4 kg/$cm^2$ at 75% load. 2. At 75% load, the difference of the maximum pressure between each cylinder was decreased from 2.4 kg/$cm^2$ to 1.8 kg/$cm^2$. 3. The fuel consumption was decreased about 8 g/ps.h at 75% load, and about 5.3 g/ps.h at 85% load. 4. The brake thermal efficiency was improved about 1.5% at 75% load and 0.9% at 85% load.

• Journal of Ocean Engineering and Technology
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• v.24 no.5
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• pp.8-15
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• 2010

The flow around a two-dimensional, rectangular cylinder that is freely falling in a channel was simulated using the immersed boundary method with direct forcing to determine the interactions between the fluid and the structure. The results of the present study were in good agreement with previous experimental results. Regardless of the H/L ratio (where H and L are the height and width of the rectangular cylinder, respectively), the flow structures had essentially the same pattern as the two symmetrical circulations that form about the horizontal center of the cylinder, with those centers located at each lateral position near the wake. When the cylinder approaches very close to the bottom, a jet-like flow appeared between the bottom of the rectangular cylinder and the channel. When the jet-like flow goes through the channel, surrounding fluids are sucked into this jet, forming the secondary vortices.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.53-58
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• 2005

An international study on Class B AIS for Non-SOLAS vessels is in progress through IMO and IEC. The IEC issued CDV(Committee Draft for Vote) on March 3, 2005, as IEC 62287, which includes operational and performance requirements, methods of test and required test results about Class B AIS. In this paper, we proposed the method of making Class B AIS properly onboard. This research deals with the problems of introducing Class B AIS which is properly applicable on small fishing vessels as well as domestic Non-SOLAS vessels. Moreover, several technical considerations were suggested to develop a national technical standards for Class B AIS.