• 한국해양공학회지
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• 제15권1호
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• pp.45-51
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• 2001

In order to clarify the seasonal variation of the residual current and the material transportation process in Hiroshima Bay, JAPAN, the real-time simulation of residual current and particle tracking by using the Euler-Lagrange model were carried out. The calculated tidal current, water temperature, and salinity showed good agreement with the observed ones. The residual currents showed a southward flow pattern at the upper layer, and a northward flow pattern at the lower layer. The flow structure of the residual current in Hiroshima Bay is an estuarine circulation affected by density flow and wind driven current. The residual current plays an important role of material transportation in the bay.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.159-164
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• 2000

In order to clarify the seasonal variation of residual current and material transportation process in Hiroshima Bay, JAPAN, the real-time simulation of residual current and particle tracking by using Euler-Lagrange model were carried out. The calculated tidal current and water temperature and salinity showed good agreement with the observed ones. The residual currents showed the southward flow pattern at the upper layer, and the northward flow pattern at the lower layer. The flow structure of residual current in Hiroshima Bay is an estuarine circulation affected by density flow and wind driven current. The residual current plays an improtant role of material transportation in th bay.

• Ocean Science Journal
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• 제42권1호
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• pp.19-30
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• 2007

This study analyzed the current meter records along with wind records for over 500 days obtained in the Kangjin Bay, South Sea, Korea spanning from March, 2003 to Nov. 2005. Various analyses include descriptive statistics, harmonic analysis of tidal constituents, spectra and coherence, the principal axis, progressive vector diagrams. These analyses can illustrate the response of residual current to the local wind resulting in the net drift with rotational motion. Current speed ranges from -28 to 33 (cm/sec), with standard deviations from 6.5 to 12.9 (cm/sec). The harmonic analyses of the tidal current show the average form number, 0.12 with semi-diurnal type and the rectilinear orientation of the major axis toward northeast. The magnitudes of the semi-major range from 12.7 to 17.7 (cm/sec) for M2 harmonics, while for S2 harmonics, they range from 6.3 to 10.4 (cm/sec), respectively. In the spectral and coherency analysis of residual current and wind, a periodicity of 13.6 (day) is found to be most important in both records and plays an important role in the net drift of residual current. The progressive vector diagrams of residual current and wind show two types of behaviors such as unidirectional drift and rotational motion. It was also found that 3 % rule holds approximately to drive 1 (cm/sec) drift current by 30 (cm/sec) wind speed based on the correlation of the semi-major axis of wind and residual current.

• 한국환경과학회지
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• 제6권4호
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• pp.313-322
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• 1997

한국수영만에서 잔차류장의 운동 위치에너지의 계절변화를 연구하기 위하여 우리는 에너지의 수지를 계산하고 조석에너지와 비교했다. 위치에너지는 겨울과 봄철에 크며, 밀도성층이 형성된 여름과 초가을에 작게 나타났다. 잔차류의 운동에너지는 계절적인 변화를 보이고 있으며, 단위면 적당 잔차류의 평균 운동에너지는 6.4$\times$$10^{-4}ergs s^{-1}cm^{-}2$이다. 수영 만에서 잔차류장의 계절변동은 조석잔차류의 운동에너지가 밀도류나 취송류의 운동에너지보다 큰 11월을 제외하고는 밀도류가 지배하고 있다. 잔차류의 주성분인 조석잔차류, 취송류 및 밀도류의 운동에너지의 평균백분율은 잔차류의 운동에너지에 대하여 각각 29.1%, 3.4%, 67.5% 이다. 단위면적당 잔차류의 운동에너지, 위치에너지 및 조석에너지의 비는 각각 1.0 : 6.7$\times$$10^3$ : 8.2$\times$$10^4$ 이다.

• 자원리싸이클링
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• 제11권5호
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• pp.34-38
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• 2002

최근 전자기기의 경박단소화로 페라이트 코아의 사용주파수가 고주파화 되고 있다. Mn-Zn ferrites에서 전력손실은 hysteresis loss, eddy current loss, residual loss로 구성되어 있으며, 500 KHz 이상의 주파수 영역에서는 residual loss가 주도적인 손실을 나타낸다. Induction level이 50 mT 이하인 경우 전력손실은 주파수의 3승 이상에 비례하여 증가한다. 작은 grain과 치밀한 미세구조는 고주파 대역에서 eddy current loss를 감소시킬 뿐만 아니라 자속밀도를 증가시켜 Residual loss역시 억제한다. Resonance frequency와 static permeability를 곱한 값이 큰 시편일수록 고주파 영역에서 낮은 전력손실을 보인다.

• 수산해양기술연구
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• 제57권3호
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• pp.214-227
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• 2021

The distribution of tidal current and tidal induced residual current, topographical eddies and tidal residual circulation in the waters surrounding the Geumo Island-An Island channel were identified through numerical model experiments and vorticity balance analysis. Tidal current flows southwest at flood and northeast at ebb along the channel. The maximum flow velocity was about 100-150 cm/s in neap and spring tide. During the flood current in the neap tide, clockwise small eddies were formed in the waters west of Sobu Island and southwest of Daebu Island, and a more grown eddy was formed in the southern waters of Geumo Island in the spring tide. A small eddy that existed in the western waters of Chosam Island during the ebb in neap tide appeared to be a more grown topographical eddy in the northeastern waters of Chosam Island in spring tide. Tidal ellipses were generally reciprocating and were almost straight in the channel. These topographical eddies are made of vorticity caused by coastal friction when tidal flow passes through the channel. They gradually grow in size as they are transported and accumulated at the end of the channel. When the current becomes stronger, the topographic eddies move, settle, spread to the outer sea and grow as a counterclockwise or clockwise tidal residual circulation depending on the surrounding terrain. In the waters surrounding the channel, there were counterclockwise small tidal residual circulations in the central part of the channel, clockwise from the northeast end of the channel to northwest inner bay of An Island, and clockwise and counterclockwise between Daebu Island and An Island. The circulation flow rate was up to 20-30 cm/s. In the future, it is necessary to conduct an experimental study to understand the growth process of the tidal residual circulation in more detail due to the convergence and divergence of seawater around the channel.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.181-184
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• 1999

The purpose of this study is to find on the Current Change and Residual current in Final closing section of Seamangum the sea dike . The M2 current was calculated in two case of the two and three point Final closing section. The residual currents are calculated diagnositically from the observed water temperature and salinity data and wind data and tidal residual current.

• 한국표면공학회지
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• 제42권4호
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• pp.145-151
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• 2009

Nanocrystalline Cu thin films for FCCL were electrodeposited from sulfate baths to investigate systematically the influences of current density, solution pH on current efficiency, residual stress, surface morphology, and microstructure of thin Cu films. Current efficiencies were measured to be approximately 100%, irrespective of the applied current density and solution pH. But these influenced residual stress, surface morphology, XRD pattern, and grain size of electrodeposited Cu thin film. The residual stress decreased with decreasing the surface roughness, but increased with increasing the fcc(111) peak strength of XRD patterns.

• 수산해양기술연구
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• 제58권2호
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• pp.159-174
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• 2022

Flow prediction was carried out through observational survey and three dimensional multi-layered numerical diagnostic model experiment to clarify the time and spatial structure of tidal current and residual flow dominant in the sea exchange and material circulation of the waters around Geumo Islands in the southern waters of Korea. The horizontal variation of tidal current is so large that it causes asymmetric tidal mixing due to horizontal eddies and the topographical effect creating convergence and dispersion of flow direction and velocity. Due to strong tidal currents flowing northwest-southeast, counterclockwise and clockwise eddies are formed on the left and right sides of the south of Sori Island. These topographical eddies are created by horizontal turbulence and bottom friction causing nonlinear effects. Baroclinic density flows are less than 5 cm/s at coastal area in summer and the entire sea area in winter. The wind driven currents assuming summer and winter seasonal winds are also less than 5 cm/s and the current flow rate is high in winter. Density current in summer and wind driven current in winter have a relatively greater effect on the net residual flows (tidal residual current + density current + density driven current) around Geumo Islands Sea area.

• 한국지구과학회지
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• 제18권6호
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• pp.529-539
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• 1997

본 연구는 2차원 순압모델을 사용하여 황해와 동중국해에서 조석잔차류와 춘 하 추 동 4계절의 해상풍에 의한 해수 순환과 이러한 순환에 의한 부유물의 이동 궤적을 추적하는데 목적을 두었다. 황해 해수 순환의 주요 외력은 조석과 바람이라고 생각되어, 조석은 $M_2$ 조석으로부터 조석잔차류를 계산하였고, 계절별 바람으로서 1월(겨울), 4월(봄), 7월(여름), 10월(가을)을 사용하였다. 조석잔차류는 한국 남 서해안과 제주도 부근과 중국 양자강 하구역 부근에서 크게 나타난다. 제주도 부근에서는 10 cm/s 이상의 최대 잔차류가 나타나며 시계방향의 순환을 보이지만 전반적으로 남해안을 따라 동향류의 경향이 있다. 또한, 중국의 연운항에서 상하이 사이의 영역에서는 한국의 남해로 향하는 순환 구조가 나타나고 있다. 바람에 의해 형성된 순환은 북풍의 성격을 띤 1월, 4월, 10월에는 해역에 시계 방향의 순환이, 남풍과 열대성 저기압의 영향을 받는 7월에는 반시계 방향의 순환이 우세했다. 이로 인하여, 한국연안에서는 7월을 제외하고는 남향류가 나타났다. 부유물은 조석 잔차류와 취송류에 의해 이동한다. 10일 동안의 이동에서는 수 십 cm/s에 달하는 취송류가 조석 잔차류보다 크게 작용했다. 그러나, 수 개월 이상의 이동에 있어서는 수 cm/s의 조석잔차류의 영향이 더 크게 나타났다.