• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.590-595
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• 2020

In this study, the small-scale collision experiments using a pendulum principle were carried out to evaluate the safety of the reinforced concrete building selected as a tsunami evacuation building due to the collision of the waterborne debris represented by ships. The experimental parameters were set as impact velocity, mass and length of the drifted ship. In this paper, the maximum impact force, impact duration, impact waveform and restitution coefficient affecting building response were investigated in detail. As a result, the impact force waveforms were distributed as a triangle in most of the experimental results, but became closer to a trapezoid as the length of the collision specimen increased. This is the very important result in calculating the momentum (impact waveform area) affecting building response, Furthermore, the restitution coefficients were constant regardless of the impact velocity, but they varied depending on the mass and length of the waterborne debris. However, the restitution coefficient for the mass per unit length of the waterborne debris can be evaluated.

• Journal of Navigation and Port Research
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• v.32 no.9
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• pp.693-698
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• 2008

The maritime education and training is executed in Asian countries according to The International Convention on Standards of Training, Certification and Watch keeping for Seafarers(STCW). However, mainly basic training and education takes in maritime universities, because this convention is minimum requirements to become junior mariner. So, until now researches have not developed to the stage of discussing how maritime universities of advanced shipping countries should pursue the direction of education in the new eras. Korea and Japan as the leading shipping countries in Asia, need to take initiatives in building a new education system in order to foster the next generation maritime expert. To enhance the professional abilities of maritime technologists in the new era, element design of science and technology relating to maritime issues and a new education system based on an amalgamation of maritime education and scientific and technological education were discussed.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.199-203
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• 2018

Because of emission control of greenhouse gas, shipbuilders, especially those in Korea, are pushing forward to introduce eco-friendly ship-building technology utilizing LNG. However, Technical skills of domestic shipbuilders in manufacturing the cryogenic pump designed to supply LNG for vessels are so low that technical skills for design and manufacturing of core parts are in urgent need. Therefore, This study described about the Rotor as a core part of cryogenic submerged centrifugal pump for ship LNG supply system. We wish to utilize for the basic data to develop the technology for the Rotor as deducing the optimal outcome with the experimental and the analytical methods in material selection.

• Journal of Ocean Engineering and Technology
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• v.23 no.5
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• pp.9-14
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• 2009

The green water on deck has many harmful effects on the vessel in rough seas such as damages to hull structures, damages to cargos, increase of the downtime, decrease of the stability, and so on. Floating Production Storage and Offloading vessels (FPSOs) are operated in a specific location and are normally positioned to meet mostly head or bow waves in order to reduce the roll motions. But this makes FPSOs more vulnerable to green water around the bow region therefore the bow shape should be properly designed to mitigate the green water damage. In this paper, experimental results in regular head waves for three kinds of bow shapes are compared and some design considerations are proposed, with the building a database for computational fluid dynamics (CFD) validation in mind.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.343-347
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• 2003

Recently, the ratio of marine casualty has been marked about 72% in fishing boat and small ships which not less than 100 tons in Korea. It is mainly against navigation regulations such as look-out, selecting the ship's course and checking the ship's position according to the analysis of marine accident. In this paper, we proposes the Intelligent Navigation Guiding System(INGS) that provides an optimum route for an operator of small ships. INGS consists of program for route planning, interface module and GPS Plotter. we obtained optimum route from specific position to established route by INGS.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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• pp.118-125
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• 2008

The deck plates of ship block is made of thin plates in their construction. A main reason of using thin plates is that deck plates don't need to support large structural loads. Therefore, out-of-plane deformations between stiffeners are frequent in deck blocks. Because these are got right by correction heating, they continuously causes quality problems in the final dock-building process. According to preceding research, the lifting process by cranes would offset the effect of correction heating. This study finds out the remained efficiency of correction heating when tensional loads are added by a lifting to corrected parts. We used inherent strains in calculating the efficiency, and established the methodology where the positions for callings are. For getting more accurate positions, besides the structural lifting analysis, welding deformation analysis with upper block and measured data from a serial ship are also referenced.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.403-408
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• 2014

Lots of electric power has been wasted through the load bank usually in the container boxes during the generator load test of the ship and offshore plant in the new ship building. Therefore in this research, the quantity of wasted electric power through generator load test under construction was investigated on big shipbuilding yard and quantity of electric power that can be recovered is analyzed when produced electric power during the generator load test is connected to KEPCO Grid, according to laboratory's experiment result where recovers electric power produced from small generator connected to KEPCO Grid.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.6
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• pp.590-600
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• 2008

This paper concerns the development of a designer friendly hull form parameterization and its coupling with advanced global optimization algorithms. As optimization algorithms, we choose the Partial Swarm Optimization(PSO) recently introduced to solve global optimization problems. Most general-purpose optimization softwares used in industrial applications use gradient-based algorithms, mainly due to their convergence properties and computational efficiency when a relatively few number of variables are considered. However, local optimizers have difficulties with local minima and non-connected feasible regions. Because of the increase of computer power and of the development of efficient Global Optimization (GO) methods, in recent years nongradient-based algorithms have attracted much attention. Furthermore, GO methods provide several advantages over local approaches. In the paper, the derivative-based SQP and the GO approach PSO are compared with their relative performances in solving some typical ship design optimization problem focusing on their effectiveness and efficiency.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.2
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• pp.132-142
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• 2017

As the International Maritime Organization (IMO) recently introduced the Energy Efficiency Design Index (EEDI) for new ships building and the Energy Efficiency Operational Indicator (EEOI) for ship operation, thus an accurate estimation of added resistance of ships advancing in waves has become necessary. In the present study, OpenFOAM, computational fluid dynamics libraries of which source codes are opened to the public, was used to calculate the added resistance and motions of the KCS. Unstructured grid using a hanging-node and cut-cell method was used to generate dense grid around a wave and KCS. A dynamic deformation mesh method was used to consider the motions of the KCS. Five wavelengths from a short wavelength (${\lambda}/LPP=0.65$) to a long wavelength (${\lambda}/LPP=1.95$) were considered. The added resistance and the heave & pitch motions calculated for various waves were compared with the results of model experiments.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.6
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• pp.698-704
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• 2011

This study aims to facilitate and increase the performance of the Traffic Analysis System which receives the location information of vessels sailing along the coast all over the country in real time and analyzes the vessels' sailing situation. Especially, the research has a signification that the system is designed with the application of Quad-Tree and R-Tree data structure in order for system users to search necessary information quickly and effectively, and it verifies the improvement of the performance by showing experiment results comparing the existing Traffic Analysis System to newly upgraded Traffic Analysis System.