• Journal of Ocean Engineering and Technology
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• v.34 no.3
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• pp.180-193
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• 2020

In this study, the end-effector tracking performance of a manipulator installed on a remotely operated vehicle (ROV) for autonomous underwater intervention is verified. The underwater manipulator is an ARM 7E MINI model produced by the ECA group, which consists of six joints and one gripper. Of the six joints of the manipulator, two are revolute joints and the other four are prismatic joints. Velocity control is used to control the manipulator with forward and inverse kinematics. When the manipulator approaches a target object, it is difficult for the ROV to maintain its position and posture, owing to various disturbances, such as the variation in both the center of mass and the reaction force resulting from the manipulator motion. Therefore, it is necessary to compensate for the influences and ensure the relative distance to the object. Simulations and experiments are performed to track the trajectory of a virtual object, and the tracking performance is verified from the results.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.290-293
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• 2001

The mid-schedule planning of the ship is making a schedule about the process from cutting to erection. The ship consists of lots of blocks. This block has different process because of the shape of the block varies in accordance with the ship-type and the part position of the ship. The type and order of each block process initially must be generated for the mid-schedule planning. In this paper, the process planning, described as above is preparing the basic information before scheduler make a plan with the prepared manhour. The scheduling is done with this process planning which includes the information of the process order. This paper shows the research about three methods to design the process planning. First, investigate the expression method about information of the process planning for the mid-schedule planning in real workplace. Second, design the object of the process planning on the basis of investigating the expression method. Finally, develop the prototype of object on the basis of this designed process planning and then find the practical use in the mid-schedule planning. The object, which is developed in this paper, contains the main algorithm. In case of developing The Mid-Schedule Planning System, this object is expected to be utilized very easily as consisting another object.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.291-305
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• 2009

As you known well, Ulsan port is very famous for handling chemical products which occupies about 80% of quantities of all Korean ports. Many ship's operators prefer to handle liquid cargo es at proper anchorages instead of the berth for saving port expenses. Ulsan M-10 anchorage was assigned for handling liquid cargoes, however this anchorage's space is restricted by the oil pipeline which lays under seabed about 400m off from the center of M-10 anchorage, for which we have to consider of the external force and counter force for keeping the safety of anchoring. Where, external force is induced by wind, tidal currents and wave while counter force is induced by holding power of anchor/chain. In this study, author evaluated a method to analyze theoretically the limit of external force condition up to which an anchoring ship can keep her position without dragging, and for which applied to many kinds of combined Ships as mother ship of 50,000 DWT Tanker and 4 sizes of Tanker as alongsided ship.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.3
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• pp.268-278
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• 2009

The present study focused on evaluation for the performance of the Flow Control Flat Plate (FCFP) attached in the stern side of the ship. The important function of this FCFP is to enhance the resistance performance through the decrease of stern sinkage and the propulsive performance by the adjustment of inflow velocities in the propeller plane. Two different hull forms were considered to identify the effects of the FCFP. The attachment position, the angle and the size of the FCFP were studied in this numerical simulation. In this paper, the roles of the FCFP were intended to analyze fully through the numerical interpretation.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.2
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• pp.78-85
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• 1999

Tracking model of a drifted ship lot the search and rescue mission in southern sea of Korea is studied. In this model, search area is determined by considering standard deviation of position around reference point. The reference point is estimated for a given type of ship when marine environmental conditions such as wind and current are given. A database for environmental data, which is necessary for the real-lime tracking of drilled ship, is gel)elated on southern sea and western sea of Korea. Using this database, the real-time prediction of wind and current is possible. The simulated trajectories and search area of our model ate validated by comparing with reported real data.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.566-574
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• 2005

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MO-ARS) might be one candidate of several systems against the ship's rolling. As the movable range of the mass on the ship is finite, the control system must include restriction on the mass position to protect the device and the ship. This restriction usually causes windup phenomenon and control performance is deteriorated seriously. Two control algorithms, anti-windup control and saturated sliding mode control, are studied in this paper. Control performance and robustness problem are checked out by numerical simulations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.30-31
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• 2018

The localization performance in the ship environment is degraded by RF interference due to steel structure characteristics and NLOS environment. In this paper, a wireless hybrid localization system using ZigBee, UWB, and LF technologies is proposed to improve position estimation accuracy in the ship environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.411-415
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• 2006

The Circumstances surrounding world ports have changed rapidly and port competition to attract more a client to each other. then, In the future, only a few ports will be survive. Therefore, industrail that concern with ports is very important position. if it revitalize, port must have international competitiveness. The purpose of this paper is as follow. The first is to investigate ship-instrument industrial with theoretical background and distribution cycle. And then, to determine the location' ship-instrument distribution center' in the Busan Port. The second is to analyze to proposal location for distribution center.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.3
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• pp.435-451
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• 2015

Evaluation of the performance of aging structures is essential in the oil and gas industry, where the inaccurate prediction of structural performance can have significantly hazardous consequences. The effects of structure failure due to the significant reduction in wall thickness, which determines the burst strength, make it very complicated for pipeline operators to maintain pipeline serviceability. In other words, the serviceability of gas pipelines and elbows needs to be predicted and assessed to ensure that the burst or collapse strength capacities of the structures remain less than the maximum allowable operation pressure. In this study, several positions of the corrosion in a subsea elbow made of API X42 steel were evaluated using both design formulas and numerical analysis. The most hazardous corrosion position of the aging elbow was then determined to assess its serviceability. The results of this study are applicable to the operational and elbow serviceability needs of subsea pipelines and can help predict more accurate replacement or repair times.

• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.377-386
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• 2020

This paper discusses the effectiveness of onboard measurements and data extracted from weather information for speed-power analysis. Furthermore, validation results of hull and propeller cleaning and painting during dry-docking are discussed. Wind and wave information can be obtained from onboard measurements or weather information from the National Oceanic and Atmospheric Administration (NOAA). The weather information of a specified position and time is extracted from NOAA weather data and compared with onboard measurements. In addition, to validate the effects of hull cleaning and painting during dry-docking, speed-power analysis results of before and after dry-docking are compared. The results show that both onboard measurements and weather information show acceptable reliability when added resistance and speed-power analysis results are compared with each other. Moreover, the ship performance analysis (SPA) software clearly shows the effects of hull cleaning and painting, and it can provide reliable analysis results with either onboard measurements or weather information. In conclusion, it is confirmed that the analysis method and SPA software used in this study are effective in analyzing the ship's speed-power performance.