• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.2 s.21
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• pp.41-47
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• 2004

Plate has cutout inner bottom and girder and Door etc. in hull construction absence is used much, and this is strength in case must be situated, but establish in region that high stress interacts sometimes fatally in region that there is no big problem usually by purpose of weight reduction, a person and freight movement, piping etc.. Because cutout‘s existence is positioning in this place, and, elastic bucking strength by load causes large effect in ultimate strength. Therefore, perforated plate elastic bucking strength and ultimate strength is one of important design criteria to decide structural elements size at early structure design step of a ship. Therefore, we need reasonable & reliable design formula for elastic bucking strength of the perforated plate. The author computed numerically ultimate strength change about several aspect ratios, cutout dimension, and plate thickness by using ANSYS Finite element analysis code based on finite element method in this paper.

• Korean Journal of Computational Design and Engineering
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• v.17 no.1
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• pp.45-53
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• 2012

In this paper, oil spreading simulation model is proposed for analyzing the oil spreading phenomenon rapidly when the ocean is polluted by the oil from a stranded ship. The space occupied by the ocean is converted into the latticed cell, and the each cell contains the information, such as the quantity of the oil, the temperature of the ocean, and the direction of current and wind. Two states, such as "clean" and "polluted" are defined in the each cell, and the oil in the cell spreads to the neighbor cells by the spreading rules. There are three spreading rules. First, the oil in the certain cell only spreads to the neighbor cells that contain larger oil than the certain cell. Second, the oil evaporates in proportion to the temperature of the ocean at the every time step. Third, the oil spreading property is affected by the direction and the speed of the current and the wind. The oil spreading simulation model of the each cell is defined by using the combined discrete event and discrete time simulation model architecture with the information and the spreading rules in the cell. The oil spreading simulation is performed when the oil of 10,000 kL is polluted in the ocean environment of 300 m by 300 m with various current and wind.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.55-60
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• 2005

Plate that have cutout inner bottom and girder and floor etc. in hull construction absence is used much, and this is strength in case must be situated, but establish in region that high stress interacts sometimes fatally in region that there is no big problem usually by purpose of weight reduction, a person and change of freight, piping etc.. Because cutout's existence gnaws in this place, and, elastic buckling strength by load causes large effect in ultimate strength. Therefore, perforated plate elastic buckling strength and ultimate strength is one of important design criteria which must examine when decide structural elements size at early structure design step of ship. Therefore, and, reasonable elastic buckling strength about perforated plate need design ultimate strength. Calculated ultimated strength change several aspect ratioes and cutout's dimension, and thickness in this investigation. Used program applied ANSYS F.E.A code based on finite element method.

• Journal of the Korean earth science society
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• v.24 no.5
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• pp.467-476
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• 2003

For the seafloor acoustic image mapping of side scan sonar, the beginning step of the procedure is to fix the absolute sonar (tow-fish) position since the sonar is not hull mounted but towed astern. The technical algorithm used to calculate the actual sonar position without any other additional sub-system, i.e., the underwater acoustic position tracking system or the sonar attitude measuring device, was proposed. In the seafloor image mosaic mapping results using the sonar track (not ship track) developed in this study, any ambiguity or inconsistency of seafloor features was not found. The incidental effect from the sonar position determination procedure orients the towing direction of sonar to be smooth, consequently the swath pattern on the across-track direction becomes stable and the blanking phenomenon of the insonification area is reduced conspicuously. This technical method is considered to be an useful tool when applied toother underwater towing vehicle surveys.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.129-135
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• 2004

Plate has cutout inner bottom and girder and floor etc in hull construction absence is used much, and this is strength in case must be situated, but establish in region that high stress interacts sometimes fatally in region that there is no big problem usually by purpose of weight reduction, a person and change of freight, piping etc. Because cutout's existence gnaws in this place, and, elastic budding strength by load rouses large effect in ultimate strength. Therefore, perforated plate elastic budding strength and ultimate strength is one of important design criteria which must examine when decide structural elements size at early structure design step if ship. Therefore, and, reasonable elastic budding strength about perforated plate need design ultimate strength. Calculated ultimate strength change several aspect ratioes and cutout's dimension, and thickness in this investigation. Used program applied ANSYS F.E.M code based on finite element method

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.04a
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• pp.163-185
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• 1998

The purpose of this study was to analyze the physiology changes by circuit weight training(CWT). The subject of this study consists of 16 student on ship(experimental groups(SE) N=8, control group(SCa) N=8) and 16 students on land (experimental groups(LE) n=8, control groups(LCb) N=8). The items of measurement were the changes of CWT time and heart rate per week, musclear functino and cardiopulmonary function. The conclusions are as follows : 1. Muscular fuction 1) Back strength in SE and LE group was increased significantly (p<.01, p<.05, 8.86% and 7.08%).Grip strength was increased slightly in 4 groups but there was no significance. 2) In push-ups, all 4 groups were increased significantly (p<.05, p<.01), sit-ups also were increased significantly in SE and LE group (p<.05, 6.71% and 9.62%). 3) In SE and LE group , standing long jump was in significantly (p<.01, p<.05, 4.49% and 6.09%), but only in LE group , side step was increased significantly (p<0.1, 5.84%). 2. Cardiopulmonary function 1) HRrest was decreased slightly in all 4 groups but was not significant changes. HRmax was increased only in LE group significantly (p<.05, 2.81%), treadmill running time was increased significantly in SE and LE group respectively (p<.01, p<.05, 10.78% and 11.07%). 2) VEmax was increased significantly in SE and LE group(p<.05, p<.01, 10.59% and 13.68%), but only in LE group Rfmax was increased significantly (p<.01, 4.83%). 3) In VO2max, LCb group was increased significantly (p<.05, 6.835), but SCa group was decreased significantly (p<.05, 4.32). VO2max/kg$.$min was increased significantly in LE and LCb group respectively (p<.01 p<.05. 4.75% and 3.98%).

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.149-149
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• 2017

Aluminum alloys have poor corrosion resistance compared to the pure aluminum due to the additive elements. Thus, anodizing technology artificially generating thick oxide films are widely applied nowadays in order to improve corrosion resistance. Anodizing is one of the surface modification techniques, which is commercially applicable to a large surface at a low price. However, most studies up to now have focused on its commercialization with hardly any research on the assessment and improvement of the physical characteristics of the anodized films. Therefore, this study aims to select the optimum temperature of sulfuric electrolyte to perform excellent corrosion resistance in the harsh marine environment through electrochemical experiment in the seawater upon generating porous films by variating the temperatures of sulfuric electrolyte. To fabricate uniform porous film of 5083 aluminum alloy, we conducted electro-polishing under the 25 V at $5^{\circ}C$ condition for three minutes using mixed solution of ethanol (95 %) and perchloric (70 %) acid with volume ratio of 4:1. Afterward, the first step surface modification was performed using sulfuric acid as an electrolyte where the electrolyte concentration was maintained at 10 vol.% by using a jacketed beaker. For anode, 5083 aluminum alloy with thickness of 5 mm and size of $2cm{\times}2cm$ was used, while platinum electrode was used for cathode. The distance between the two was maintained at 3 cm. Anodic polarization test was performed at scan rate of 2 mV/s up to +3.0 V vs open circuit potential in natural seawater. Surface morphology was compared using 3D analysis microscope to observe the damage behavior. As a result, the case of surface modification showed a significantly lower corrosion current density than that without modification, indicating excellent corrosion resistance.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.2
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• pp.136-143
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• 2018

3-D templates are produced to evaluate completeness of the shell plates during the forming process, which is an essential step for the ship production. They are mostly produced in advance during the detail/production design stage, but occasionally they are requested by the shell plate forming department, because it is impossible to predict accurately the necessities of them at the design stage. This results in a huge loss of man-hour and a bottleneck. In order to resolve this issue while reducing the dependence on other department, the process of manufacturing the 3-D templates needs to be automated. Therefore, this study proposes an automatic system that calculates the manufacturing information of the 3-D templates with only geometric information of the shell plates. The system considers the thickness and the cutting method of the parts of the 3-D templates and some options are provided to reflect the intention of the worker.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.325-330
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• 2006

The container terminal is the unified transportation system which connects between a land transportation and a sea transportation. This system has many subsystems such as ship operation, yard transfer operation, yard storage system, gate operation, and information manage system. This paper presents a method of modeling a simulator with which user can evaluate the efficiency of the equipment and allocation policies in the container terminal. The final purpose is to estimate the efficiency of each equipments and the distribution policies. In a design step in the simulator development. We suggest the Object Oriented method with which the developer can easily design, because the object oriented method has the advantages of reusability and modularity.

• Journal of Navigation and Port Research
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• v.37 no.4
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• pp.383-390
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• 2013

After forming a institutional framework with specified in Maritime Safety Law(ex. Maritime Traffic Safety Law) on May 27th, 2009, The efforts for improving 'Maritime Traffic Safety Assessment Scheme(MTSA scheme)' have continued to the present. But there's no review with the comprehensive and systematic approach for proceeding acceleration step of MTSA scheme. At this point, this study analyzed current status and derived improvement measures using by 'PIP'OU model' which was designed for the comprehensive analysis in accordance with metaevaluation theory, like as question investigation and etc. Consequently, it mainly needs to improve 'Assessment Plan' domain and minimized the difference in views between concerned parties. This study is expected to be used to develop systematic maritime policy by proposing the order of priority in improvement matters.