• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.65-66
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• 2005

This paper presents an adaptive satellite communication systems to adapt channel environment. High performance coding and modulation techniques are applied to poor channel condition, otherwise, bandwidth efficient coding and modulation techniques are applied to good channel condition to obtain high transmission rate.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.111-111
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• 2012

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.269-269
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• 2012

• Animal cells and systems
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• v.12 no.3
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• pp.171-180
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• 2008

The complete larval development of Pagurus japonicus(Stimpson) is described, based on laboratory rearing. The species has four zoeal stages and a megalopa. The larvae are described and illustrated, and detailed comparisons with other pagurid larvae in the Korean coast are made.

• Animal cells and systems
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• v.6 no.2
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• pp.125-143
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• 2002

Heterotrophic flagellates occurring in the marine sediments of Inchon and Ganghwa Island are reported. Fifty-six species from 38 genera were encountered in this survey and two new taxa were recorded: Cyranomonas australis sp. nov. and Gweamonas unicus sp. nov. There was little evidence for endemism because all flagellates including the two new taxa described here have been found from other habitats in Australia which are geographically remote from Korea. This study supports the model that free-living heterotrophic flagellates have a world-wide distribution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.2
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• pp.159-168
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• 2010

This paper presents a mathematical model and simulation method for investigating the performance of set net systems and fish cage systems influenced by currents and waves. Both systems consist of netting, mooring ropes, a floating collar and sinkers. The netting and ropes were considered flexible structures and the floating collar was considered an elastic structure. Both were modeled on a mass-spring model. The structures were divided into finite elements and mass points were placed at the mid-point of each element, and the mass points were connected by mass-less springs. Each mass point was subjected to external and internal forces and the total force was calculated at every integration step. An implicit integration scheme was used to solve the nonlinear dynamic system. The computation method was applied to dynamic simulation of actual systems simultaneously influenced by currents and waves in order to evaluate their practicality. The simulation results improved our understanding of the behavior of the structure and provided valuable information concerning the optimized design of set net and fish cage systems exposed to an open ocean environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.131-138
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• 2012

The tourism industry is considered as the world largest industry and it is assessed as the most effective way to create employment. In particular, the marine tourism industry such as marine leisure sports, cruise can create high added value so that its significance has been more emphasized. Korea has natural tourist attractions such as more than 3,000 islands, about 12,000km lengths coastline, wide wetlands and beautiful seascape. In addition, the establishment of the five-day workweek and the development of means of transportation make the policy demand of the public for marine tourism increase continuously. However, Korea currently lacks policy and system for revitalizing marine tourism industry as the new growth engine and has not made good use of its retained tourist resource. Accordingly, this study explores the current situation and challenges of Korean marine tourism industry and further analyses the limits of the national legal systems for marine tourism. Lastly, it suggests policy recommendation for promoting marine tourism industry.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.5
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• pp.596-608
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• 2018

The present study aims to assess test uncertainty assessment method of nominal wake field measurement by a Stereoscopic Particle Image Velocimetry (SPIV) system in a towing tank. The systematic uncertainty of the SPIV system was estimated from repeated uniform flow measurements. In the uniform flow measurement case, time interval between image frames and uniform flow speed were varied to examine the effects of particle displacement and flow around the SPIV system on the systematic standard uncertainty. The random standard uncertainty was assessed by repeating nominal wake field measurements and the estimated random standard uncertainty was compared with that of laser Doppler velocimetry. The test uncertainty assessment method was applied to nominal wake measurement tests of a very large crude oil carrier model ship. The nominal wake measurement results were compared with existing experimental database by other measurement methods, with its assessed uncertainty.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.330-340
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• 2005

Compressible two-phase flow is analyzed based on the arbitrary Lagrangian-Eulerian (ALE) formulation. For water, Tamman type stiffened equation of state is used. Numerical fluxes are calculated using the ALE two-phase Godunov scheme which assumes only that the speed of sound and pressure can be provided whenever density and internal energy are given. Effects of the approximations of a material interface speed are Investigated h method Is suggested to assign a rigid body boundary condition effectively To validate the developed code, several well-known problems are calculated and the results are compared with analytic or other numerical solutions including a single material Sod shock tube problem and a gas/water shock tube problem The code is applied to analyze the refraction and transmission of shock waves which are impacting on a water-gas interface from gas or water medium.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.130-138
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• 2007

A coupled variational equation for fluid-structure interaction (FSI) problems is derived from a steady state Navier-Stokes equation for incompressible Newtonian fluid and an equilibrium equation for geometrically nonlinear structures. For a fully coupled FSI formulation, between fluid and structures, a traction continuity condition is considered at interfaces where a no-slip condition is imposed. Under total Lagrange formulation in the structural domain, finite rotations are well described by using the second Piola-Kirchhoff stress and Green-Lagrange strain tensors. An adjoint shape design sensitivity analysis (DSA) method based on material derivative approach is applied to the FSI problem to develop a shape design optimization method. Demonstrating some numerical examples, the accuracy and efficiency of the developed DSA method is verified in comparison with finite difference sensitivity. Also, for the FSI problems, a shape design optimization is performed to obtain a maximal stiffness structure satisfying an allowable volume constraint.