• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.58-65
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• 2000

A target signal simulation method for passive sonar systems is introduced. The method uses multirate signal processing techniques to simulate moving target signals in the multi-path sound propagation environment by introducing Lloyd's mirror and Doppler effect. Time and frequency variation of target signal due to the target maneuvering is also considered to provide realistic ship signatures in the LOFAR gram so that the simulated target is used for sonar operator training. Synthesized target characteristics is analyzed and compared with real target signal in terms of interference pattern and frequency variation in the LOFAR gram.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.336-345
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• 2020

Vessel Traf ic Services (VTS) is a system for ship safety and accident prevention. The International Maritime Organization (IMO), the International Association of Marine Aids to Navigation and the Lighthouse Authorities (IALA) established regulations related to VTS from an early stage. On December 3, 2019, South Korea enacted a special act called the "Act on Vessel Traffic Services (VTS Act)," which will take ef ect on June 4, 2020. In this paper, the background of this act's enactment is examined and its provisions are critically reviewed. In particular, the study intensively examines the reasons the immunity provisions for the VTS operator were removed and the current direction of improvements to the VTS Act is presented in terms of its feasibility. Most countries that do not have an Act related to VTS and its operator, refer to that of Korea. Therefore, it is necessary to reinforce the structures and definition of the VTS Act, as well as the immunity provisions for the VTS operator. The latter were removed during the National Assembly's legislation process, but were included in the initial bill, and should be reflected in subsequent revisions of the VTS Act.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.42-57
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• 1995

An efficient and accurate scheme has been constructed by taking advantages of the hi-quadratic spline scheme and the higher-order boundary element method selectively depending on computation domains. Boundary surfaces are represented by 8-node boundary elements to describe curved surfaces of a ship and its neighboring free surface more accurately. The variation of the velocity potential complies with the characteristics of the 8-node element on the body surface. But on the free surface, it is assumed to follow that of the hi-quadratic spline scheme. By which, the free surface solution is free from numerical damping and has better numerical dispersion property. As numerical examples, steady and unsteady Neumann-Kelvin problems are considered. Numerical results for a submerged spheroid, Series 60($C_B=0.6$) and a modified support the proposed method. Finally, a new upstream radiation condition is derived using a wave equation operator in order to deal with problems for subcritical reduced frequency. The relevance of this operator has been confirmed in the case of unsteady Kelvin source potential.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.476-482
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• 2013

This study aims to enhance the effectivity of VTS(Vessel Traffic Service) control by investigating the minimum safe distance between vessel and vessel, vessel and land(obstacle) for the vessel's safe navigation within the VTS control area. In addition, to suggest basic data for the safe navigation, this study has done survey and analysis to each VTS center, and individual on the minimum safe distance to VTS operators of each ports of korea. Through ocean voyage by training ship, Singapore and Malacca strait's congested vessel traffic zone's control distance was compared and investigated the difference on safe distance by the different VTS operators. As a result, there was huge difference of minimum safe distance between the VTS operators belong to the same center. Over all, the port with gentle coastline, like donghae, the safe distance was wider than the other port. On the other hand, port with complex coastline and frequent entry and departure of the vessel, like mokpo, the safe distance was the shortest of all. Therefore, development of module suitable to port's natural conditions and traffic volume's necessity is required, for the operators affiliated to the same VTS center control according to formal method. Lastly, the full discussion by the expert group about establishment of standard control procedure in the future should be considered as well.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.717-723
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• 2007

In recent years, the transportation sector has been undergoing very rapid and multifarious changes due to the M&A, alliances between shipping companies, introduction of larger container ship as it cost reduction measure and the application of integrated logistics to satisfy the needs of customers. Therefore, container terminal is required adequate terminal facilities, sufficient channel depth, efficient handling and low cost of port fees and dues. The purpose of this paper is for functional assessment of efficient container terminal. Firstly, the container operating process information about yard equipment and chassis is extracted through the analysis of practical daily work report of container terminal. Also, the formulae of skill factor and troubles of operator on transfer crane are defined. Lastly, container handling simulation model which consideration of skill factor and trouble of operator is proposed by Petri network model.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.517-517
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• 2000

Welding automation is one of the most important manufacturing issues in shipbuilding in order to lower the cost, increase the quality, and avoid the labor problems. Generally the on-line teaching is utilized on the robot that is used in the welding automation system, but it requires much effort and long time to program. Especially, if the system is composed of more than two cooperating robots, it demands much more skill to program the robots' motion. Thus, a convenient programming tool is required for efficient utilization of welding automation system. In this study, a convenient programming tool is developed for welding automation in which gantry-robot system is used. The system is composed of a gantry transporter and two robots mounted on the gantry to cover the wide work range in the ship building application. As a programming tool, an off-line programming software based on PC is developed. By using this software, field operator does not need to concern about coding of task programs for three control units, one is for gantry and two are for robots. The task programs are automatically generated by assembling the program modules in database according to geometrical information of workpiece and welding condition, which become the only concern of field operator, The feasibility of the generated programs can be verified via a motion simulator previously to on-line running.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.2
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• pp.131-136
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• 2011

The furrow calculation and traffic measurement of sailing ship using computer vision are useful methods to prevent maritime accident by predicting the possibility of an accident occurrence in advance. In this paper, sailing ships are recognized using image erosion, differential operator and minimax value, which can be verified directly because the calculated coordinates are displayed on electronic navigation chart. The developed algorithm based on area information of this paper has the advantage which is compared to the conventional radar system focused on point information.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.132-134
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• 2011

In Communications are intended elicit respondses through a conversation or communication styles between speaker and audience. VTSO and the ship operator's intent to communicate well with each other thus leading to the conclusion that must be accomplished It should be completed with MRC which is a poor means to understand and persuasive manner, and conclusions expressed are easily able to derive strategic communication skills. Forever, but these expression and technic can not force where the operator deciding factor in the law frame should not spiral out of the border. VTSO communication skills should be taken into such factors would be high level technic. Now here's I'd like to study that occured in the maritime communications field to be studied deeper issues and a category of expression technic, expression for the VTSO.

• Korea Trade Review
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• v.45 no.5
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• pp.141-159
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• 2020

Container terminals at Gwangyang Port are operated by three container operators: A, B and C. Ultimately, there is consensus that a single operator should operate all terminals so that economies of scale can be achieved even in the operation of the container terminal. Integration between operators has a positive effect on both operators and shipping companies. From the operator's point of view, overlapping fixed costs between operators can be unified, reducing overall costs and utilizing spare facilities. On the other hand, from the viewpoint of the shipping company, it is possible to ensure stable use of the port facilities and always allow berthing, reduce days on demurrage and ship waiting, and provide one-stop service for work. However, existing cases of operators' integration or relocation of terminals remained to estimate the expected effects of alternatives, emphasizing only the financial point of view. The port terminal is a large system, and it is important to consider that it is an aggregate of major logistics facilities and equipment. Moreover, if the estimation can be made by quantifying the expected effect, the justification of the terminals' relocation can be further emphasized. Therefore, it is very important to estimate the expected effect from the viewpoint of systemic operation. Moreover, the need for operators' integration can be further emphasized if it can be estimated through quantification of expected effects. Currently, three alternatives are considered as alternatives to the terminals' relocation, and in this study, the optimal plan was derived for the 3 alternatives by the linear planning model of the minimum shuttle transportation cost in the terminal. The optimal plan is alternative 2, which shows the most advantageous integration effect in terms of expected effects. Alternative 2 integrates the B terminal into the C terminal, and the A terminal operates independently as it is.

• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.11-19
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• 2013

The Korean naval weapon systems, combat experiments establish the concept of Battle operations, and create the future of the new weapons system. Doctrine development and training as well as ranging from experiments for evaluate the performance of mission operations for combat experiments are used. The battle lab is effectively support tool for the Korean Naval battle experiments. The battle lab is through a dedicated testing facility and to build efficient and effective simulation-based acquisition supporting environment. In this paper, the ship / submarines C2 operations virtual simulator was developed to support the concept of Battle operations of naval combat experiments in training and tactical development. The ship C2 operations virtual simulator makes the anti-ship and anti-aircraft the engagement scenario for performed experiments using the SADM. The submarines C2 operations virtual simulator makes the anti-submarine engagement scenario for performed experiments using EAS. EAS System was created before reuse. EAS system by modifying the additional interfaces HLA-RTI has been reused. Reflected in the tactics and training after analysis of the results through the battle experiment. Also increase training fidelity through operator involvement. The anti-ship and anti-aircraft system architecture (SADM) and anti-submarine system architecture (EAS) requires unique design of system framework since two separate architectures should be integrated into a system. An C2 virtual linked architecture was used to integrate different system architecture. A C2 virtual linked software framework, designed that have integrated protocol for battle experimental linkage and battlefield visualization environment.