• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.125-134
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• 2004

The improvement of artificial respiration method has brought about the decrease in mortality of pulmonary diseases patients. Various respiratory curative methods, inclusive of HFOV (High Frequency Oscillatory Ventilation), have been developed for more effectual and less harmful management of acute respiratory failure. However, the mechanism of gas transfer and diffusion in a bronchiole has not yet been clarified in detail. As a first approach to the problem, we measured oscillatory flows in a Y-shaped micro-channels as bronchiole model by micro Particle Image Velocimetry(micro PIV). In order to establish the fundamental technique of PIV measurements on oscillatory air flow in a micro-channel, we used about 500-nm-diameter incense smoke particles, a diode laser, a high speed camera including an objective lens, and a HFOV, which is effective technique for medical care of pulmonary disease patients, especially, infants. The bronchiole model size is that parent tube is $500\{mu}m$ width and $500\{mu}m$ depth, and daughter tubes are $450\{mu}m$ width and $500\{mu}m$ depth. From this study made on the phenomenon of fluid in micro size bronchus branch of a lung, we succeeded to get time series velocity distribution in a micro scale bronchial mode. The experimental results of velocity distribution changing with time obtained by micro PIV can give fundamental knowledge on oscillatory airflow in micro-channel.

• 한국태양에너지학회 논문집
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• 제33권1호
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• pp.7-14
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• 2013

This study has analysed the ultimate loads acting on a wind turbine which is operating in a high turbulent flow condition because the ultimate loads are critical factors on the safe design of wind turbine. Since wind flow on the most parts of Korean mountainous are strongly influenced by complex configurations of the topography, turbulence intensity on somewhere is so stronger than an international design standard. For this reason, the characteristics of turbulent wind data collected from actual sites were analyzed and used for the ultimate load evaluation of the wind turbine. With the 270 design load cases on the international standards, the differences of ultimate loads on the wind turbine operating in the standard or high turbulent wind condition are calculated and compared for the an enhanced knowledge of the safe design basis. As are result, it is revealed the specific ultimate loads are strongly affected by the high turbulent wind conditions, thus the characteristics of turbulent flow must be considered during the design of wind turbine.

• 디지털융복합연구
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• 제10권7호
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• pp.11-22
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• 2012

지식정보경제에서 무형자산은 부와 성장을 결정하는 중요한 역할을 한다. 특히 기업이 보유한 무형자산 중 대표적인 특허에 대한 평가가 많은 주목을 받고 있다. 중소벤처기업의 활동이 경제의 큰 부분을 차지하면서 이들이 보유한 특허의 가치를 어떻게 평가할 것인가에 대한 문제가 실무 및 학계에서 큰 관심의 대상이 되고 있다. 중소벤처 기업에 대한 인수 합병, 투 융자 등에서 가장 중요하게 고려되는 것이 특허가치에 대한 평가이기 때문이다. 이러한 필요성에 의해 본 연구에서는 특허가치평가를 위해 평가대상기업 재무제표를 이용하여 매출총이익으로부터 영업이익을 계산한 후 법인세, 자본비용을 고려하고 감가상각비는 증감함으로써 초과이익을 계산하고 현가계수를 곱하여 현재가치를 구하게 되며, 여기에 기여도를 곱함으로써 궁극적인 무형자산 가치를 구하게 되는 DCF모형과 사례분석을 제안하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.86-86
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• 2022

While estuarine dams can develop freshwater resources and block the salt intrusion, they can result in increased sediment deposition in the estuary. The mechanism of increased sediment deposition in an estuary with an estuary dam is not well understood. To fill this knowledge gap, 7 ADCP measurements of flow and suspended sediment concentration (SSC) were collected along-channel in an estuary with an estuarine dam over a neap-spring cycle. Flow and SSC were used to calculate the sediment flux and sediment flux gradients. The results indicated that the cumulative sediment fluxes at all stations were directed landward. The along-channel sediment flux gradient was negative, which indicated deposition along the channel. The landward mean-flow fluxes were dominant in the deep portion of the channel near the estuary mouth, whereas landward correlation fluxes were dominant in the shallow portion of the channel near the estuarine dam. The tides were the dominant forcing driving the sediment fluxes throughout the estuary.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.702-705
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• 2006

정보의 폭발적인 증가로 인해 연구 개발을 위한 전 과정 중 연구동향 분석에 많은 시간이 소모되고 있다 최근 특정 분야의 지식이 연구개발이나 제품개발로 이루어지던 시대에서 융합지식을 통한 연구개발이나 제품생산으로 빠르게 진화하고 있다. 이러한 패러다임을 수용하기 위해 기존의 독립적이고 단편적인 정보로부터 융합정보를 제공할 수 있는 체계로의 전환이 필요하게 되었다. 또한 과학 기술 정책 및 산업 정책을 수립하기 위해 최근 과학, 기술, 산업의 지식 흐름에 대한 연구가 활발히 진행되고 있으나 정량적인 분석을 활용하기란 매우 어려운 문제이다. 왜냐하면 과학-기술간 지식흐름을 분석할 수 있는 정보자원이 존재하지 않기 때문이다. 이 연구는 연구개발이나 과학기술정책 및 산업정책에 활용할 수 있는 특허정보와 학술 문헌간 강 결합 연계 체제를 갖는 프레임웍을 개발하고자 한다.

• 정보교육학회논문지
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• 제15권1호
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• pp.1-10
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• 2011

교육 현장에서 프로그래밍 교육은 고등 사고력 향상을 위한 학습보다는 프로그래밍의 개념이나 기초 문법의 주입 및 단순 반복으로 진행되고 있다. 따라서 학습자들이 프로그래밍 교육에 대해 긍정적인 흥미를 가지고 적극 참여하여 교육적인 효과를 거둘 수 있는 새로운 프로그래밍 교육 방안에 대한 모색이 필요하다. 스크래치 EPL(Educational Programming Languages)은 블록 쌓기를 통해 프로그래밍이 가능한 직관적인 언어로 초등학생들도 보다 쉽게 프로그래밍을 이해할 수 있다. 스크래치의 이런 특징은 프로그래밍 교육에 대한 학습자의 학습 몰입(Flow)에 긍정적인 영향을 미칠 수 있다. 따라서 본 연구에서는 프로그래밍 교육의 새로운 방안으로 스크래치 프로그래밍 교육을 진행하고 초등학생의 학습 몰입과 프로그래밍 능력에 미치는 영향에 대해 검증하고자 한다. 본 연구의 결과 스크래치 프로그래밍 교육이 학습자의 전반적인 학습 몰입 수준 향상에 긍정적인 효과가 있음을 알 수 있다.

• Archives of Reconstructive Microsurgery
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• 제24권2호
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• pp.75-78
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• 2015

High-pressure (HP) injection injury to the upper extremity often causes a very serious clinical problem, leading to poor outcomes, including amputation, so that a true surgical emergency is required. The outcomes can be improved with emergent wide surgical debridement. However the diagnosis of these injuries is often delayed due to underestimated evaluation at first appearance and lack of common knowledge of the seriousness of this injury. The type and pressure of the infecting material is an important factor in prognosis and organic solvents infected pressure injury can cause poor outcome and increased amputation rate. In this case, we report on reconstruction of HP oil-based paint injection injuries of the finger using T-shaped pedicles and multiple venous anastomoses. In this concept, arterial flow can be maintained by the reverse flow of distal anastomosis when there is difficulty with the proximal anastomosis. And venous flow can be preserved by deep and superficial vein anastomosis. This concept has various advantages including preserving patency of the pedicle in chronic vasculopathy or trauma cases and maintaining the arterial flow by the reverse flow of distal anastomosis and can improve the free flap survival by a two vascular anastomosis system.

• 대한기계학회논문집B
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• 제21권1호
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• pp.165-173
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• 1997

The present study investigates heat/mass transfer for flow through perforated plates for application to combustor wall and turbine blade film cooling. The experiments are conducted for hole length to diameter ratios of 0.68 to 1.5, for hole pitch-to-diameter ratios of 1.5 and 3.0, for gap distance between two parallel perforated plates of 1 to 3 hole diameters, and for Reynolds numbers of 60 to 13, 700. Local heat/mass transfer coefficients near and inside the cooling holes are obtained using a naphthalene sublimation technique. Detailed knowledge of the local transfer coefficients is essential to analyze thermal stress in turbine components. The results indicate that the heat/mass transfer coefficients inside the hole surface vary significantly due to flow separation and reattachment. The transfer coefficient near the reattachment point is about four and half times that for a fully developed circular tube flow. The heat/mass transfer coefficient on the leeward surface has the same order as that on the windward surface because of a strong recirculation flow between neighboring jets from the array of holes. For flow through two perforated plate layers, the transfer coefficients on the target surface (windward surface of the second wall) affected by the gap spacing are approximately three to four times higher than that with a single layer.

• 한국약용작물학회지
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• 제5권3호
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• pp.196-201
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• 1997

당귀 반수체 육성의 기초차료를 얻고자 배양 소포자의 활력과 특성을 Flow cytometry로 관찰한 바 그 결과를 요약하면 다음과 같다. 1. 소포자 활력은 발육 시기에 따라 차이를 보여 배양 4일경에 4분자기 12.8%, 1핵성소포자기 49.3%, 2핵성소포자기 42.3% 및 성숙화분은 56.4%였다. 그리고 배양 20일 경에 는 소포자의 활력이 감소하여 배양중 배지개선과 계대배양이 요구됨을 알 수 있었다. 2. 발육시기에 따라 소포자 구조 peak가 다르게 조사되어 4 분자기는 원형을 보이다가 $1{\sim}2$핵성 소포자 부터 성속 화 분은 장타원형의 발달하는 특성을 띠었다. 3. 배양 소포자 중 살아서 생존한 소포자는 FDA 염색에 녹색 형광을 DAPI 염색에 청색형광을 발하여 활력이 있음을 알 수 있었다.

• Wind and Structures
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• 제11권2호
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• pp.75-96
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• 2008

A better understanding of tornado-induced wind loads is needed to improve the design of typical structures to resist these winds. An accurate understanding of the loads requires knowledge of near-ground tornado winds, but observations in this region are lacking. The first goal of this study was to verify how well a CFD model, when driven by far field radar observations and laboratory measurements, could capture the flow characteristics of both full scale and laboratory-simulated tornadoes. A second goal was to use the model to examine the sensitivity of the simulations to various parameters that might affect the laboratory simulator tornado. An understanding of near-ground winds in tornadoes will require coordinated efforts in both computational and physical simulation. The sensitivity of computational simulations of a tornado to geometric parameters and surface roughness within a domain based on the Iowa State University laboratory tornado simulator was investigated. In this study, CFD simulations of the flow field in a model domain that represents a laboratory tornado simulator were conducted using Doppler radar and laboratory velocity measurements as boundary conditions. The tornado was found to be sensitive to a variety of geometric parameters used in the numerical model. Increased surface roughness was found to reduce the tangential speed in the vortex near the ground and enlarge the core radius of the vortex. The core radius was a function of the swirl ratio while the peak tangential flow was a function of the magnitude of the total inflow velocity. The CFD simulations showed that it is possible to numerically simulate the surface winds of a tornado and control certain parameters of the laboratory simulator to influence the tornado characteristics of interest to engineers and match those of the field.