• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.98-99
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• 2016

The aim of study is to develop a dual driven ship berthing/deberthing system with $360^{\circ}$ steerability. A large ship used bow thruster, side thruster and pod propulsor etc. when approaching to a pier. But as marine leisure boats become large-scaled, the number of accidents is recently increasing what caused a ship to crash into a ship and a ship to crash into mooring facilities during berthing/deberthing on a marina. To solve the problem, the control responsiveness of a joystick connected with two motors and a propeller was checked and torque was increased by the electromagnetic design of magnetic gear. A sea trial test was carried out to investigate a performance of the developed system in the real sea.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.62-67
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• 2015

A very large shell-structure built in shipyards like ship hulls or offshore structures are joined by welding through full process. As the welding contains a high thermal cycle at a local area, the welded structures should be distorted unavoidably. Because a distorted ship block should be revised to the designed value before the next stage, the ability to predict and to control the weld distortion is an accuracy level of the yard itself. Despite the ship block size, several present thermal distortion methodologies can deal those sizes, but it is a different story to deal full ship size model. Even a fully constructed ship hull not remaining any welding can have an accuracy issue like outfitting installation problems. Any present thermal distortion methodology cannot accept this size for its recommended element size and the number. The ordinary welding breadth at erection stage is about 20~40 mm. It can hardly be a good choice to make finite element model of these sizes considering human effort and computational environment. The finite element model for structure analysis of a ship hull is prepared at front-end engineering design stage which is the first process of the project. The element size of the model is as fine as the longitudinal space, and it is not proper to obtain a weld distortion at the erection stage. In this study, a methodology is suggested that a weldment can be shrunk at original place instead of using structural finite element model. We cut the original shell elements at erection weld-line and put truss elements between the edges of cut elements for weld shrinkage. Additional truss elements are used to facsimile transverse weld shrinkage which cannot be from the weld-line truss element shrink. They attach to weld-line truss element like twigs from barks. The capacity of developed elements is verified through an accuracy check of erection process of a container vessel at the apt. hull. It can be a useful tool for verifying a centering accuracy after renew and for block-separating planning considering accuracy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.196-201
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• 2002

The SSB(Single Side Band) communication in the 27MHz band has mainly been using between fishiery station and small fishing ship less than 10tons, but the most of small fishing ship are depend on cellular system. When accident for small ship at sea happens, It's very important to communicate continuously for preventing the collision and taking action. At present it is hard to control small fishing ship and provide information properly by using 27MHz SSB channel. Therefore in this paper We present TRS communication system applied for small fishing ship to protect the safy and life at sea and to prepare for emmergency, and also validate it's application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.767-773
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• 2014

An economic ship routing means to sail a ship with a goal of minimizing the fuel consumption by utilizing weather forecast information, and there have been various systems which have been recently studied. For a successful economic ship routing system, it is needed to properly control an engine power or change a geographical path considering weather forecast. An optimal geographical path is difficult to be determined, though, because it is a minimal dynamic-cost path search problem where the actual fuel consumption is dynamically variable by the weather condition when the ship will pass the area. In this paper, we propose an geographical path-search algorithm based on evolutionary strategy to efficiently search a good quality solution out of tremendous candidate solutions. We tested our approach with the shortest path-based sailing method over seven testing routes and observed that the former reduced the estimated fuel consumption than the latter by 1.82% on average and the maximum 2.49% with little difference of estimated time of arrival. In particular, we observed that our method can find a path to avoid bad weather through a case analysis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.179-185
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• 2014

A use of Asbestos onboard was banned by the provisions of SOLAS since 1 January 2011. And this provision was also implemented by the Rule for Ship's Facilities in Korea. However, these provisions were only declaration and there were no detailed measures for detect, removal and confirmation. In this study, by reviewing the Ship Recycling Convention, IMO circulars and Asbestos Safe Management Act, the following strategies for each concerned parties were proposed. The administration and class society should establish the provisions for appointment of subject vessel which to be inspected for asbestos, criteria for asbestos management and appointment of handling expert. The shipbuilder and equipment manufacturer should make written confirmation that asbestos was not used in their product. And shipowner and ship manager should establish procedure for onboard control of asbestos in the ship's safe management system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.191-200
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• 2000

The marine accident is being highlighted as a serious worldwide problem for the guard station of human safety and the protection of marine environment pollution. Especially, the GMDSS is operated as a international rule for the safety of a large scale ship, but the small size ship's management is required a adaptive national rule because of the complex condition of national circumstance. This study is motivated to develop a ship's position tracking system combined with GPS information for VTS and control the ship navigation, velocity and longitude etc.. In Part of Navigation Data Transmission is GPS data transmission whih ship's ID using microprocessor and TX speed translation for flexibility with 4800∼2400 [bps]. Results show that the our system for data transmission using microprocessor is useful tool in maritime transmission as SSB used the main TX method of small ship and has a cost competitive power. Therefore, we will expected cost and technical competitive power compared to AIS. But those systems are still remained the unsolved problem for protection from marine accident.. Finally, we examined the semi-actual receiving state on simulated sailing in the around sea of Mok-Po harbor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.906-912
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• 2012

A ship ad-hoc network (SANET) can provide ships with diverse multimedia services by replacing expensive satellite communications. While ITU-R M. 1842-1, standards for maritime VHF band digital communications, can be used as the specifications of physical layer for SANETs, no standards are specified for higher layers of SANETs. In this paper, we propose a ship ad-hoc communication (SAC) protocol for SANETs, based on medium access control (MAC) and routing protocols for terrestrial ad-hoc networks. SAC protocol is a cross-layer protocol which combines MAC and routing into one algorithm and considers maritime environments, including the existence of neighboring ships, the possibility of routing to a destination, and changing the communication mode in case of VHF channel failure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5450-5456
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• 2011

In order to build a ship, painting on ship cargo tank is one of the most dangerous parts as it involves working in high altitudes and a closed ship cargo tank. Therefore, researchers have been developing devices that will enable mobile robots to operate on vertical walls. The wall-climbing robots have been widely used to attach on the wall such as suction types. These types can be utilized regardless of the wall material. However, it is required to adhere and control the suction cups. To moderate this drawbacks, this paper proposes an automatic painting robot that uses a permanent magnet mobile robot. Using the magnetic characteristics, this robot can move on the boat vertically and horizontally even while hanging on the ceiling of the ship cargo tank. Also, we made a prototype to test adhesive force of the permanent magnet wheel and mobile robot as well as the towing capacity and auto-piloting ability.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.276-279
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• 2009

Is introducing ship automation system for the safety of ship and work environment mend recently. Is endeavoring for sea safety and fire at sea prevention solidifying control of standard technology and safety supervision aspect in IMO but sea accident and ship fire are happening continuously. Because using Robot in artistic talent of ship in this treatise, studied that correspond to Risk and manage. Attach fire perception sensor for Robot's Risk confrontation, and because using infrared rays sensor, TOUCH SWITCH, sound perception sensor, gas perception sensor, light perception sensor that is threaded in Robot and is achieved, controlled Robot, and establish Low-High value the speed of sound output use and DC MOTOR and COM SEN of when indicate Risk confrontation to Robot and establish Robot's Risk confrontation administration action.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.783-788
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• 2021

Although the Korean government (Ministry of Ocean and Fisheries) and related organizations are enforcing many policies to improve the marine safety of vessels with weak safety management, the effectiveness of each policy is deficient due to the lack of a risk assessment method for ship safety management. Most previous studies in Korea of the risk assessment of ships only dealt with fragmentary risks of individual marine accident risks, so a new assessment method for comprehensive marine accident risk is needed. Examples of comprehensive risk assessments for ship safety management are the selection method for inspection targets by the Port State Control and the Norwegian Maritime Authority. In this study, indicators for the comprehensive risk assessment of ship safety management were developed for and applied to coastal/offshore fishing vessels that occupy a high proportion of the registrations and marine accidents in Korea. As a result, the risk of each ship was confirmed quantitatively, and a ranking of the weakness factors for ship safety management was identified.