• Korean Journal of Ichthyology
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• v.8 no.2
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• pp.47-56
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• 1996

Hydrography of the Korea Strait was influenced by the various water masses such as Korean coastal water, East Sea cold water, and Tsushima Current. Anchovy larvae were frequently found in the area influenced by the Tsushima Current. Anchovy appeared in all seasons and were most abundant in summer. Anchovy was more abundant in the middle layer(30~70m) than the surface layer in spring and summer and was little in the deeper layer beyond the depth of 100m. It was most abundant in the surface layer in autumn, and decreased toward the deeper layer. They were more abundant in the middle layer(30~50m) than in the surface layer and the bottom layer in winter. Anchovy was most abundant in the depth of 30m to 70m during the day time, however it was more abundant in the surface layer during the night time. Although vertical distribution patterns of abundance varied seasonally and diurnally, most of the larval anchovy distributed in the upper layer within the depth of 100m and in the upper layer above the thermocline in summer and autumn.

• Korean journal of applied entomology
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• v.27 no.4
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• pp.194-199
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• 1988

The seasonal movements of Holotrichia morosa and H. diomphalia in soil were investigated during the period from 1984 to 1986 in Suwon. Most cf the eggs, active larvae and adults of the two species could be found at the soil depth of I-IDem. The larvae began downward movement in late October and early November in order for overwintering when soil tempe¬rature at 5cm below ground reached about $10^{\circ}C$. The overwintering depths of the larvae were 10-40cm for H. morosa and 30-80cm for H. diomPhalia. After the overwintering, pupation and adult emergence of H. morosa occurred at the overwintered sites, \vhereas H. diomPhalia larvae returned to near soil surface next April, and resumed feeding. H.diomphalia larvae began to move downward again in late June for pupation and adult emergence, and overwintered thereafter as adults at the depth of 1O-40cm.

• Korean Journal of Environment and Ecology
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• v.15 no.2
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• pp.186-192
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• 2001

본 연구는 전라남도 광양만의 6개 임해매립지 식재지반의 토양환경 특성을 조사분석하였다. 토심이 깊어짐에 따른 토양성질의 수직적 특성은 각 식재지반별로 다르게 나타났다. 토양성질의 수직적 특성에 영향을 미치는 요인은 개토와 준설토의 이질서, 토양의 물리. 화학성의 교란, 지반하부에 잔존하는 염류의 이동, 유기물의 이동과 강우나 가뭄 등이었다. 수목생 상 유리한 식재지반은 식재지반의 높이가 낮은 곳보다 높은 성토지역이었으며, 이것은 토양의 물리. 화학적 교란과 지하부의 염류로부터 안전성이 높기때문이었다. 조경식물의 생육상 불리한 토양성질들은 토성의 이질서, 토양의 경화, 알칼리성 염류토양, 높은 ECe, Na, K. 저농도의 Ca, Mg, T-C등이었으며, 이러한 토양성질들은 표토보다는 지하의 근권부에 주로 분포하여 있었다. 따라서 임해매립지 식재지반 조성시에는 토양의 성질이 교란되지 않은 방법이 모색되어야 하며, 조경수목의 생육에 관련된 토양환경조사는 지하근권부 이하까지 정밀하게 조사. 분석하여야 할 것으로 사료되었다. 사료되었다.

• Economic and Environmental Geology
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• v.46 no.4
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• pp.313-327
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• 2013

In the study, three-dimensional geostatistical simulations on McMurray Formation which is the largest oil sand reservoir in Athabasca area, Canada were performed, and the optimal site for steam assisted gravity drainage (SAGD) was selected based on the predictions. In the selection, the factors related to the vertical extendibility of steam chamber were considered as the criteria for an optimal site. For the predictions, 110 borehole data acquired from the study area were analyzed in the Markovian transition probability (TP) framework and three-dimensional distributions of the composing media were predicted stochastically through an existing TP based geostatistical model. The potential of a specific medium at a position within the prediction domain was estimated from the ensemble probability based on the multiple realizations. From the ensemble map, the cumulative thickness of the permeable media (i.e. Breccia and Sand) was analyzed and the locations with the highest potential for SAGD applications were delineated. As a supportive criterion for an optimal SAGD site, mean vertical extension of a unit permeable media was also delineated through transition rate based computations. The mean vertical extension of a permeable media show rough agreement with the cumulative thickness in their general distribution. However, the distributions show distinctive disagreement at a few locations where the cumulative thickness was higher due to highly alternating juxtaposition of the permeable and the less permeable media. This observation implies that the cumulative thickness alone may not be a sufficient criterion for an optimal SAGD site and the mean vertical extension of the permeable media needs to be jointly considered for the sound selections.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.78-84
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• 2013

The objective of this paper is to develop 360 W class wind turbine tree using a helical type wind turbine. The performance of 100 W class helical wind turbine which finished the conceptual design has been forecast through the CFD analysis. After performed the analysis of one wind turbine performance, four wind turbine have been installed at the structure of a tree type and then the change of a output data has been verified through the CFD analysis. In this study, the CFD results of a helical wind turbine tree have been shown by a velocity and pressure distribution. The result could obtain more than rated power 360 W through the CFD analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.59-63
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• 2006

A direct photograph measurement technique was used to determine the spatial distribution of the spray droplet diameter in subsonic crossflow and it also obtain that SMD distribution by using PLLIF technique. The injector internal flow was classified as three modes such as a normal, cavitation, and hydraulic flip. The objectives of this research are getting a droplet distribution and drop size measurement of normal flow and compare with the other flow effects. Although the study showed visually that drop size were spatially dependent of Air-stream velocity, fuel injection velocity, and normalized distance from the injector exit length.(x/d, y/d) There are also difference characteristics between cavitation, hydraulic flip and the normal flow.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.2
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• pp.299-306
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• 1989

The combined convective heat transfer from vertical parallel plates with constant temperature has been studied by numerical method. The governing equations for the system are solved by the finite difference method and successive over relaxation scheme for Re$_{L}$ = 50 - 500, Gr = 10$^{4}$, Pr = 0.7. Results for various plate spacings and plate lengths are as follows ; For various plate spacings, the mean Nusselt number increases and then decreases as the dimensionless plate spacing increases. The optimum plate spacing for maximum mean Nusselt number decreases with increasing Reynolds number and can be expressed as a function of Reynolds number. For various plate lengths, the mean plate Nudest number increases as the dimensionless plate length decreases and Reynolds number increases.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.1
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• pp.62-72
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• 2008

In this study, an analytical model has been developed to predict the build-up of heat field due to a point heat source in the presence of sharp cross-flow depth change. The model has been applied to investigate the effect of the depth change and flow pattern on the heat field. Model results show that, when there is a sharp depth change in cross-flow direction, the heat transport across the boundary of the depth change is enhanced or diminished according to the increasing or decreasing of the horizontal diffusion flux. Including residual components as well as tidal currents give rise to reduce the effect of the horizontal diffusion on the heat transport because of increasing the advection of heat.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.352-357
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• 2006

매년 도로와 주차공간의 확장보다 차량의 수가 빠르게 증가하여 그에 따라 불법 주차 관리의 어려움이 증가하고 있다. 이러한 문제점을 해결하기 위해 지능형 주차 관리 시스템이 필요하게 되었다. 본 논문에서는 획득된 차량 영상에서 수직 에지의 특징을 이용하여 번호판 영역과 개별 코드를 추출하고, 추출된 개별 코드를 퍼지 신경망 알고리즘을 제안하여 학습 및 인식한다. 본 논문에서는 차량 번호판 영역을 검출하기 위해 프리윗 마스크를 적용하여 수직 에지를 찾고, 차량 번호판의 정보를 이용하여 잡음을 제거한 후에 차량 번호판 영역을 추출한다. 추출된 차량 번호판 영역은 반복 이진화방법을 적용하여 이진화하고, 이진화된 차량 번호판 영역에 대해서 수직 분포도와 수평 분포도를 이용하여 번호판의 개별 코드를 추출한다 추출된 개별 코드는 제안된 퍼지 신경망 알고리즘을 적용하여 인식한다. 제안된 퍼지 신경망은 입력층과 중간층간의 학습 구조로는 FCM 알고리즘을 적용하고 중간층과 출력층간의 학습 구조는 Max_Min 신경망을 적용한다. 제안된 방법의 추출 및 인식 성능을 평가하기 위하여 실제 차량 영상 150장을 대상으로 실험한 결과, 기존의 차량 번호판 인식 방법보다 효율적이고 인식 성능이 개선된 것을 확인하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.103-103
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• 2021

실험실에서의 파랑생성에 흔히 사용되는 피스톤형 조파장치는 수심에 따라 유속이 동일하게 생성된다는 제약이 있어 주로 천해파의 생성에 적합한 것으로 알려져 있다. 본 연구에서는 이러한 제약조건 없이 다양한 유속분포의 파형을 생성하는 수직 다열화된 조파장치가 개발되었다. 우선, 수심방향으로 이산화된 각 패들(paddle)의 스트로크에 대해 선형해석해가 유도되었다. 개발된 해석해는 패들의 수 및 유속분포에 따라 기존의 피스톤형 혹은 플랩형 조파장치 해석해로 근사함이 밝혀짐으로써 포괄적으로 활용될 수 있음이 확인되었다. 즉 개발된 해석해를 활용하면 선택적으로 피스톤형 및 플랩형 조파성능이 구현될 수 있다. 더불어 개발된 해석해는 다상유체의 내부파 생성에도 확정되어 적용가능함이 확인되었다. 다음으로, 개발된 조파장치를 수치적으로 구현하였다. 오픈소스 3차원 수치모형인 OpenFOAM 중, 두 개 이상의 불연속 및 비압축 유체에 대한 Navier-Stokes 방정식을 해결하는 수치 모듈을 사용하여 제안된 수직다열화된 조파장치의 성능이 평가되었다. 이때 동적격자모델(olaDyMFlow)을 결합함으로써 개발된 조파장치 움직임이 물리적 조파장치와 흡사하도록 수치적으로 구현하였다. 모의결과, 여러 개의 다열화된 패들이 층류 흐름 조건에서 심해파를 효율적으로 생성시키고, 중간수심 파랑조건에서는 제안된 조파장치가 상대적으로 덜 유리함을 확인할 수 있었다. 마지막으로 공기, 기름 및 물 등 3상의 흐름조건에서 단 두 개의 패들을 활용하여 각각 내부파 및 표면파를 생성하되었으며, 모의 결과는 해석해과 비교됨으로써 개발된 조파장치의 성능이 검증되었다.