• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.204-208
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• 2002

Mooring is the operation of securing a ship to a wharf or quay by means of rapes or chains. A. moored ship need not necessarily be truly stationary. It may be free to rise and fall with the tick or the loading and unloading of cargo or to oscillate in response to the action of the environmental forces. In this respect a moored ship is restricted to a limited amount of movement within well-defined bounds. This study is intended to analyze the tension of mooring lines by a FEM program, as the current velocities and working directions are varied. The motion of a berthed ship is studied concerning with the wave periods and the direction. Also the behavior of the modeled vessel are investigated for a berthed condition.

• The Journal of the Acoustical Society of Korea
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• 제22권3E호
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• pp.133-140
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• 2003

A time series simulation is presented by a ray approach for the simulating the received waveform of a broadband acoustical signals interacting with the ocean boundaries. The environment is assumed to be horizontally stratified, and the seafloor is described in terms of homogeneous fluid half-space. The ray approach includes the effects of reflection from the air-water, water-sediment interface and phase shifts due to boundaries interaction. To generate time series, we assume that the acoustic energy propagates from source to receiver along eigenrays and represent the action of the bottom on the incident wave by a linear filter and characterized in the frequency domain by the transfer function. As example application, the time series for an explosive source in a shallow water environment is calculated and analyzed in terms of acoustical process. good agreement with measured time series is demonstrated.

• 한국패류학회지
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• 제31권3호
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• pp.221-232
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• 2015

Observations in beach, intertidal and upper subtidal environments in Peter the Great Bay (north-western East Sea) have shown that attached algae were found on empty shells of 13 species of epifaunal and infaunal bivalve mollusks. Thirteen algae species were identified on empty dislodged shells but more than 50 species are known to be epibiotic on living bivalves. The dislodgement of shells with attached algae takes place in semi-enclosed, low-energy areas, as well as those which are open and affected by strong wave action, indicating the large scale of this phenomenon. The significance of seaweed transportation of living mollusks and their empty shells in the coastal zone, involving both taphonomic and ecological processes, is stressed. Algae appear to be a taphonomic agent and play a similar role as compared to birds or hermit crabs, but they act passively and contribute to environmental mixing in death assemblages in coastal environments.

• Journal of Advanced Marine Engineering and Technology
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• 제13권3호
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• pp.64-71
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• 1989

In this paper, a computer program for simulation of 4 cycle diesel engines including intake and exhaust manifold system is developed. The wave action theory is applied for optimization of the intake and exhaust manifold system. The calculation results of this computer program is finely accurate and agreed well with experimental results. Accordingly, it is recognized that the developed computer program can be utillized very usefully for the design of intake and manifold system. And then, influential factors of the engine performance in the design of intake manifold is numerically investigated by the calculation only. As the results it is concluded that the inertia one of the dynamic effects on the intake and exhaust maninfold affects mainly the engine performance and the pulsation one is a side effect.

• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.548-553
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• 2015

The conventional ejector-diffuser system makes use of high pressure primary stream to propel the secondary stream through pure shear action for the purposes of transport or compression of fluid. It has been widely used in many industrial applications such as seawater desalination, solar refrigeration, marine engineering, etc. The present study is performed numerically to study the performance of a two-stage ejector-diffuser system. The detailed flow phenomenon of the ejector-diffuser system has been critically predicted by means of the numerical approach using compressible Reynolds averaged Navier-Stokes (RANS) equations. The axi-symmetric supersonic ejector-diffuser flow has been solved by a fully implicit finite volume scheme with a two-equation k-omega turbulence model. The numerical results are validated with existing experimental data. Detailed flow physics and their contributions on ejector performance are detected to compare both single-stage and two-stage ejectors. The performance improvement on the ejector-diffuser system is discussed in terms of the mass flux ratio and the coefficient of power.

• 한국패류학회지
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• 제24권2호
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• pp.81-87
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• 2008

Distribution, population structure, and growth of the bivalve Protothaca euglypta were investigated for clams collected from the northwestern part of the East Sea of Russia. This species is distributed in further northern area than it was found earlier. In the southern area, this clam is found in the intertidal zone, up to 8 m in depth. It is one of the most numerous infaunal species of bivalves, and protected to wave action in the gravel-pebble and sand with rubble biotope. Population density of P. euglypta reaches 500 $spc./m^2$, and biomass 2 $kg/m^2$. Size and age composition of the local settlements and allometric growth of P. euglypta depend on a biotope. The growth rate of P. euglypta considerably reduces in case of the northern boundary area, whereas life span increases.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1685-1690
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• 2007

Wave and following checking cycle arbor in the mountains form that examine various theories that decide checking cycle and data and application possibility that can acquire actually were presented. If see in standpoint that breakdown detects singularity availability before change happening, problem is advanced how action of device may do ordinary times supervision (monitoring) or checking cycle. In checking cycle decision, situation of latency breakdown that can not know that cause breakdown before device that is using examines can exist. Example such as car examination, faur and equitable spirit health examination, security device etc. can be fatal the time. Therefore, study and examined arbor in the mountains room of family proper checking cycle.

• 한국안전학회지
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• 제9권2호
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• pp.3-11
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• 1994

This study discribes result of comparision of two other numerical method, method of characteristics (MOC) and Lax-Wendroff method(LWM) applied at wave action analysis of Intake and exhaust pipe. Partiality FCT(Flux Correct Transport) scheme is appeneded to LWM to protest unacceptable overshoots, occuring near discontinuity. The final conclusion of this study is that MOC should be replaced by a second order finite difference approach(such as the LW method). Clear benefits we can get by change are faster calculation, higher accuracy, conservation of mass and consistent calculation method.

• Journal of Advanced Marine Engineering and Technology
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• 제22권5호
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• pp.693-701
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• 1998

This study presents result of comparison between two other numerical method method of char-acteristics(MOC) and Lax-Wendroff method(LWM) applied at wave action analysis of intake and exhaust pipe in terms of calculated pressure velocity and emitted noise in the time and the fre-quency domain by means of fast Fourier transform analysis. Particularly FCT(Flux Corrected Transport)scheme is appended to LWM to protest unaceptable overshoots occurring near discon-tinuity. The final conclusion of this study is that MOC should be replaced by a second order finite difference approach because of larger contributions due to high frequency components than the results from the method of characteristics. Clear benefits we can get by change are faster calcula-tion higher accuracy conservation of mass and consistent calculation method.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.145-146
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• 1998

A planar-type silicon microelectrode array has been fabricated and used successfully in obtaining simultaneous multichannel recordings from peripheral nerve of invertebrates. This paper demonstrates that planar-type semiconductor electrode arrays are useful for studying traveling wave properties of action potential.