• 한국농공학회지
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• 제42권
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• pp.24-30
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• 2000

A system for evaluating streamflow data (KORSAS) was developed, and is operated using PC based Windows to help the hydrological observation practitioner's working in Korea Water Resources Corporation (KOWACO). This system has modules including; DB access and data management, flow measurement arranging, H-Q relation deriving, area rainfall calculating, flow calculating, and flow evaluating modules. Evaluation of observed streamflow is accomplished through the following processes. First, hourly streamflow data is calculated from water level data stored in a DB server by applying the rating relationship between water level and flow rates derived from the past flow measurements. Second, hourly areal rainfal data is calculated from point data stored in the DB server by applying Thiessen networks. Third, hydrographs are displayed on a daily, weekly, monthly, or seasonal duration basis, and are compared to hydrographs of reservoir inflow, hydrographs at water level observation stations and hydrographs derived from simulated results using models.

• 한국콘텐츠학회논문지
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• 제20권9호
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• pp.150-157
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• 2020

본 연구는 PBL 환경에서 과제참여 수준에 대한 몰입의 영향을 문제해결력이 매개하는지 탐색하기 위해서 수행되었다. 본 연구의 대상은 교육방법 및 교육공학 수강하는 예비유아교사 60명의 학생들을 대상으로 하였다. 연구를 위해서 몰입, 문제해결력, 과제참여 수준을 설문을 통해서 자료를 수집하였다. 수집된 자료는 SPSS Macro 및 부트스트래핑(bootstrapping)방법을 사용하여 과제참여 수준에 대한 몰입의 영향에 대해 문제해결력이 매개 효과를 분석하였다. 그 결과, 과제참여 수준에 대해 몰입의 영향이 정적인 것으로 나타났으며, 문제해결력이 .292 수준에서 간접효과가 있는 것으로 나타났다. 이는 과제참여 수준에 대한 몰입의 영향을 문제해결력이 매개하는 것으로 검증되었다. 이와 같은 연구결과를 통해서 PBL 활동에서 문제해결력 지원을 통해 과제참여 수준을 향상할 수 있는 시사점을 제시할 수 있다.

• 한국산학기술학회논문지
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• 제13권2호
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• pp.827-833
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• 2012

본 논문은 2D/3D 변환에서 깊이정보 생성을 위해 연산량을 감소시키는 레벨 간소화 기법을 적용하고 객체의 고유벡터를 이용하여 노이즈를 제거한 Optical flow를 이용하는 방법을 제안한다. Optical flow는 깊이정보를 생성하기 위한 방법 중 하나로 두 프레임간의 픽셀의 변화 벡터 값을 나타내어 움직임 정보를 나타내며 픽셀 단위로 처리하므로 정확도가 높다. 그러나 픽셀 단위 연산으로 긴 연산 시간이 소요되며 모든 픽셀을 연산하는 특성상 노이즈가 생길 수 있는 문제점이 있다. 본 논문에서는 이를 해결하기 위해 레벨 간소화 과정을 거쳐 연산 시간을 단축하였고 Optical flow를 영상에서 고유벡터를 갖는 영역에만 적용하여 노이즈를 제거한 뒤 배경 영역에 대한 깊이 정보를 에지 영상을 이용하여 생성하는 방법을 제안하였다. 제안한 방법으로 깊이정보를 생성한 뒤 DIBR(Depth Image Based Rendering)으로 2차원 영상을 3차원 입체 영상으로 변환하였고 SSIM(Structural SIMilarity index)으로 최종 생성된 영상의 오차율을 분석하였다.

• 컴퓨터교육학회논문지
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• 제12권1호
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• pp.15-22
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• 2009

컴퓨터 프로그래밍 언어 학습은 프로그래밍과 디버깅 과정을 통해 컴퓨터 작동원리를 이해할 수 있을 뿐만 아니라, 논리적 사고력, 문제해결력과 같은 고차원적 사고능력을 함양시켜주는 교육적 효과가 있다. 본 연구에서는 프로그래밍 언어 학습에서 학습자들의 내재적인 학습 동기를 유발하고 학습을 지속시키기 위한 방안으로 몰입이론을 적용하였다. 이를 위해 몰입의 구성 요소를 적요한 교수 학습 전략들을 개발한 후, 이것을 WBI로 설계, 구현하였다. 또한, 구현된 WBI를 실제 교수-학습 현장에 적용하여, 학습자의 몰입수준 변화와 학업성취도에 미치는 효과에 대해 검증하였다. 그 결과 몰입이론을 적용한 WBI 학습이 학습 목표의식과 도전감, 구체적인 피드백을 이루어 몰입 수준 향상에 효과적이었으며, 몰입 경험이 학습 결과에 긍정적인 영향을 끼쳐 학업성취도(프로그래밍 능력)의 향상에 효과적이었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.935-938
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• 2007

In suction nozzle of a vacuum cleaner, where flow-induced noise is generated mainly by flow resistance, several ideas to reduce noise are investigated. To increase fan performance, blade number is optimized and a centrifugal fan is replaced by a cross-flow fan, In addition, gear ratio of fan to drum brush is changed. It is found that fan performance is increased by adopting these methods. Next, the blade height of the fan is decreased to reduce sound pressure level, which causes inevitably decrease in fan performance. Eventually, flow-induced noise is reduced by 6.3 dBA in its overall level with the fan performance maintained.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2018년도 춘계 종합학술대회 논문집
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• pp.53-54
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• 2018

This paper introduces an approach to detect motion areas of stationary objects when the camera slightly moves in the scene by computing optical flow. The flow field is computed by two pyramidal architectures of 5 levels which are built by down-sampling the size of the images by half at each level. Two pyramids of images are built and then optical flow is computed at each level. A warping process combines the information and generates a final flow field after applying edge smoothness and outliers reduction steps. Moreover, we convert the flow vectors in order of magnitude and angle to a color map using a pseudo-color palette. Experimental results in the Middlebury optical flow dataset demonstrate the effectiveness of our method compared to other approaches.

• 한국수산과학회지
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• 제24권1호
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• pp.59-69
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• 1991

Two-level numerical models are formulated to predict the flow pattern, SS(suspended solids) distribution and the behavior of discharged fresh water in estuary, and are applied to the Suyoung River estuary in Pusan, Korea. To verify the application of the models, field observations of tidal current, salinity and 55 were performed during the period of spring tide. Computed upper level velocities by two-level model are in better agreement with observed values than single model. Apart from the magnitude of the velocities, the predicted flow fields at upper level are similar to those obtained at lower level. Upper level velocities in river channel during ebb spring tide are about 2 times stronger than those during flood spring tide due to the discharging flow rate from the Suyoung River. Two-level model results on the salinity and 55 distribution at upper level are compared with the observed ones at the surface. Computed salinity distributions are in good agreement with the observed values, but computed 55 distributions show $6{\~}10$ ppm higher values than the observed ones.

• 한국의류학회지
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• 제34권4호
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• pp.606-616
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• 2010

This study investigates the flow that customers experience when they participate in a design process for the mass customization of apparel products according to participation level and individual personalities. In addition, how the flow influences the satisfaction and final purchase intention is also examined. The subjects were 600 female consumers. The following results were found: First, the level of mass customization was higher, the enjoyment, concentration, product satisfaction, and total satisfaction were higher. Second, the paths of 'participating ability'$\rightarrow$'flow', 'flow'$\rightarrow$'satisfaction'$\rightarrow$'satisfaction' 'final purchase intention' were significant. The process satisfaction had a more significant influence on the final purchase intention than the product satisfaction. Finally, the participation ability had a moderating effect for the flow experience according to the level of mass customization.

• Journal of Power Electronics
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• 제18권2호
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• pp.588-603
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• 2018

This paper presents the idea of a smart load that can adjust the input power flow based on the intermittent power available from RESs (Renewable Energy Resources) to regulate the line voltage, and draw a constant power from the grid. To this effect, an innovative power flow controller is presented based on a Resistive ES (Electric Spring) in combination with a PEAT (Power Electronics based Adjustable Transformer), which can effectively shape the load power flow at the subnetwork level. With a PEAT incorporated in the step down transformer at the grid side, the proposed controller can supply non-critical loads through local RESs, and the critical loads can draw a relatively constant power from the grid. If there is an abundance of power produced by the RESs, the controller can supply both non-critical loads and critical loads through the RES, which significantly reduces the power demand from the grid. The principle, practicality, stability analysis, and controller design are presented. In addition, simulation results show that the power flow controller performs well in shaping the load power flow at the subnetwork level, which decreases the power demand on the grid. Experimental results are also provided to show that the controller can be realized.

• 한국환경과학회지
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• 제25권12호
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• pp.1727-1738
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• 2016

In this study, groundwater flow was analyzed targeting Dae-jeong watershed, which exhibited the largest variations of groundwater levels at the identical elevation points among the 16 watersheds of Jeju Island. The issues of the methods applied in practice were identified and improvement plans were suggested. This groundwater-flow estimates derived by applying hydraulic conductivity values onto zones of equal topographic ground level were found to be quite different from actual measured groundwater flow. Conversely, groundwater-flow estimates that utilized hydraulic conductivity values applied onto groundwater-level equipotential lines indicated relatively lesser divergences from actual measured groundwater flow. The reliabilities of the two approaches were assessed for 60 randomly selected points on DEM (digital elevation model) maps, The method using hydraulic conductivity values applied onto groundwater-level contours turned out to be the more reliable approach for the Dae-jeong watershed in Jeju Island.