• 한국가시화정보학회지
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• 제9권4호
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• pp.47-53
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• 2011

A water driven ejector loop was designed and constructed for air absorption. The used ejector was horizontally installed in the loop and annular water jet at the throat entrained air through the circular pipe placed at the center of the ejector. Wide range of water flow rate was provided using two kinds of pumps in the loop. The tested range of water flow rate was 100${\ell}$ /min to 1,000 ${\ell}$/min. Two-phase flow inside the ejector loop was simulated by CFD analysis. Homogeneous particle model was used for void fraction prediction. Water and air flow rates and pressure drop through the ejector were automatically recorded by using the LabView based data acquisition system. Flow characteristics and air bubble velocity field downstream of the ejector were investigated by two-phase flow visualization and PIV measurement based on bubble shadow images. Overall performance of the two-phase ejector predicted by the CFD simulation agrees well with that of the experiment.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2003년도 추계학술대회 논문집
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• pp.67-70
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• 2003

Hard disk drives (HDD) in computer are used extensively as data storage capacity. The trend in the computer industry to produce smaller disk drives rotating at higher speeds requires an improved understanding of fluid motion in the space between disks. Laser sheet and digital camera was used for 2-dimensional visualization of the unsteady flow between the center pair of two co-rotating disks in air with a cylindrical enclosure (or shroud). Geometric parameters are gap height (H) between disks, and gap distance (G) between disk tip and shroud. The lobe-structured boundary between inner region and outer region was detected by inserted particles, and the number of dominant vortices was determined clearly It is found from flow visualization that the number of vortex cells can be correlated with Reynolds number based on H which is defined as $Re_H={\Omega}RH/v$ ranging from $3.18\times10^3\;to\;1.43\times10^4$, and decreases as the disk speed increases. The lobe pattern by vortex cells is changed to a circular pattern for the wide gap than narrow one.

• 한국가시화정보학회지
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• 제2권2호
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• pp.66-72
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• 2004

The heat transfer and pressure drop characteristics of $CO_{2}$ are substantially different from those for CFC and HCFC refrigerants. In addition, geometric effects on two-phase flow patterns of $CO_{2}$ are also very significant in many respects. Therefore, two-phase flow patterns of $CO_{2}$ in a narrow rectangular channel or a small diameter tube whose gap size or hydraulic diameter is less than 2 mm are very important to understand heat transfer characteristics and to develop an appropriate heat transfer correlation. In the present study, the evaporation process of $CO_{2}$ in a narrow rectangular channel is visualized at various test conditions, and then the effects of operating conditions are analyzed.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2002년도 추계학술대회 논문집
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• pp.39-42
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• 2002

In the current study, characteristics of the laser-induced plasma were investigated in a gas filled chamber or in a gas jet by using a relatively low intensity laser $(I\;\leq\;5\;\times\;10^{12}\;W/cm^2)$. Temporal evolutions of the produced plasma were measured using the shadow visualization and the shock wave propagation as well as the electron density profiles in the plasma channel was measured using the Mach-Zehnder interferometry. Experimental results such as the structure of the produced plasma, shock propagation speed $(V_s)$, electron density profiles $(n_e)$, and the electron temperature $(T_e)$ are discussed in this study. Since the diagnostic laser pulse occurs over short time intervals compared to the hydrodynamic time scales of expanding plasma or a gas jet, all the transient motion occurring during the measurement is assumed to be essentially frozen. Therefore, temporally well-resolved quantitative measurements were possible in this study.

• 대한핵의학회지
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• 제13권1_2호
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• pp.15-21
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• 1979

1975년(年) 1월(月)부터 1978년(年) 3월(月)까지 경북의대부속병원(慶北醫大附屬病院)에서 진단(診斷)된 만성골수성백혈병(漫性骨髓性白血病) 가운데 18례(例)에서 $^{198}Au$교질(膠質)을 사용(使用)하여 간비주사(肝脾走査)를 시행(施行)하여 다음과 같은 소견(所見)을 얻었다. 1) 만성골수성백혈병(漫性骨髓性白血病)의 남녀비(男女比)는 2:1이였고 연령적(年齡的)으로 30대(代)와 40대(代)가 많았다. 2) 간비주사(肝脾走査)에서 간(肝)의 공간점유병변(空間占有病變)을 의심(疑心)할 만한 소견(所見)은 없었다. 3) 비섭취(脾攝取)는 well visualization 군(群) 4례(例) poor visualization 군(群) 7례(例), nonvibualization 군(群) 7례(例)였고, visualization 군(群)에서 비내공간점유병변(脾內室間占有病變)을 의심(疑心)할 소견(所見)은 없었다. 4) 비(脾) well visualization 군(群)과 poor visualization군간(群間)에는 임상(臨床所見) 간기능검사소견(肝機能檢査所見) 및 혈액학적소견(血液學的所見)에서 큰 차이(差異)가 없었다. 5) 비(脾) nonvibualization 군(群)에서는 visualigation 군(群)에 비(比)해서 증상기간(症狀期間)이 비교적(比較的) 길었던 례(例)가 많았고, 혈소판감소증(血小板減少症) 및 골수(骨髓)의 거핵구감소증(巨核球減少症)의 례(例)가 많았으나 간기능검사소견(肝機能檢査所見)에서는 별차이(別差異)가 없었다. (본(本) 논문교열(論文校閱)의 노고(勞苦)를 아끼지 않으신 황기석학장(黃基錫學長)님께 충심(衷心)으로 감사(感謝)드립니다.)

• 대한핵의학회지
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• 제5권1호
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• pp.49-64
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• 1971

The radioactive $^{131}I$-rose bengal serial scintiphotography was performed in 62 patients with the hepatobiliary diseases and in 20 normal subjects. This approach permitted visualization of the hepatic uptake of $^{131}I$-rose bengal from the circulation and its excretion into the biliary trees and the intestines. In some of these patients, gallbladder function was examined, using eggs as a gallbladder constrictor. The time of maximum hepatic uptake was well correlated to the conventional biochemical liver function tests. In addition to $^{131}I$-rose bengal scintiphotography, $^{198}Au$-colloid scintiphotography was also performed to make comparison of these two tests. The results obtained were as follows: 1. In normal subjects, the maximum hepatic uptake of $^{131}I$-rose bengal occurred at $23{\pm}2.9$ minutes, the initial hepatic excretion at $34{\pm}5.1$ minutes, the visualization of the gallbladder at $29{\pm}5.7$ minutes and the intestinal visualization at $54{\pm}25.8$ minutes. The radioactivity in the gallbladder decreased to $10.7{\pm}5.0%$ one hour after the ingestion of eggs. 2. In the patients with cirrhosis of the liver, there was a delayed and decreased hepatic uptake. The maximun hepatic upake occurred at $43{\pm}12.9$ minutes. The differences in the results of uptake between the cirrhotic and the normal group were statistically significant. The initial hepatic excretion occurred at $60{\pm}18.5$ minutes and had tendency of delaying compared with the normal controls. The gallbladder was visualized in 13 of 16 cases (81%) and its visualization occurred at $49{\pm}14.6$ minutes with a tendency to be delayed compared with the normal controls. The intestinal visualization occurred at $63{\pm}15.8$ minutes and its delaying tendency was somewhat more prominent. 3. In patients with hepatitis, the maximum hepatic uptake occurred at $59{\pm}21.4$ minutes and was significantly delayed. The initial hepatic excretion occurred at $82{\pm}34.3$ minutes and the results revealed a delaying tendency. The gallbladder was visualized in 15 of 20 cases (75%) at $57{\pm}18.7$ minutes, which was significantly delayed. The Intestinal visualization was noted in all cases with marked delay. 4. In patients with obstructive jaundice, the maximum hepatic uptake was noted at $83{\pm}14.7$ minutes, showing the most significant delay. The hepatic excretion into biliary trees and intestines was not entirely noted in all cases except the only one case with gallbladder visualization. 5. In patients with cholelithiasis, the maximum hepatic upake and the initial hepatic excretion were slightly delayed with mean times of $39{\pm}11.2\;and\;48{\pm}17.1$ minutes respectively. The visualization of the gallbladder was demonstrated in 10 of 17 cases (59%) and occurred at $52{\pm}25.6$ minutes with a slight delay. The intestinal visualization occurred at $67{\pm}47.7$ minutes and was slightly delayed. $^{131}I$-rose bengal in the gallbladder remained high, $49.3{\pm}21.3%$, which suggested quantitatively decreased power of gallbladder constriction. 6. The time of the maximum hepetic uptake was correlated well to BSP retention and serum alkaline phosphatase ativity. However, the maximum hepatic uptake had no definite correlation with serum albumin, serum globulin, TTT, serum cholesterol, SGPT or SGOT. 7. In the diagnosis of the hepatobiliary diseases with jaundice, $^{131}I$-rose bengel serial scintiphotography has proved to be more useful than $^{198}Au$-colloid scintiphotography. With these results, it could be justified that $^{131}I$-rose bengal scintiphotography is an excellent diagnostic aid for dynamic hepatobiliary function studies in the clinical practice.

• Journal of Advanced Marine Engineering and Technology
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• 제32권7호
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• pp.1036-1043
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• 2008

The Flow fields of a ship's propulsion mechanism of Weis-Fogh type were investigated by the PIV. Velocity vectors and velocity profiles around the operating and stationary wings were observed at opening angles of ${\alpha}=15^{\circ} and $30^{\circ}$, velocity ratios of V/U=$0.5{\sim}1.5$ and Reynolds number of Re=$0.52{\times}10^4{\sim}1.0{\times}10^4$. As the results the fluid between wing and wall was inhaled in the opening stage and was jet in the closing stage. The wing in the translating stage accelerated the fluid in the channel. And the flow fields of this propulsion mechanism were unsteady and complex, but those were clarified by flow visualization using the PIV.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1661-1665
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• 2004

Hard disk drives (HDD) in computer are used extensively as data storage capacity. The trend in the computer industry to produce smaller disk drives rotating at higher speeds requires an improved understanding of fluid motion in the space between disks. Laser sheet and digital camera was used for 2-dimensional visualization of the unsteady flow between co-rotating disks in air with a cylindrical enclosure (or shroud). Geometric parameters are gap height (H) between disks, and gap distance (G) between disk tip and shroud. The lobe-structured boundary between inner region and outer region was detected by inserted particles, and the number of dominant vortices was determined clearly It is found from flow visualization that the number of vortex cells can be correlated with Reynolds number based on H which is defined as $Re_H={\Omega}RH/v$ ranging from $7.96{\times}10^2$ to $1.43{\times}10^4$, and decreases as the disk speed increases. The lobe pattern by vortex cells is changed to a circular pattern for the wide gap than narrow one.

• 지능정보연구
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• 제20권2호
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• pp.39-58
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• 2014

빅데이터의 중요성에 대한 인식이 확산되고, 관련한 기술이 발전됨에 따라, 최근에는 빅데이터의 처리와 분석의 결과를 어떻게 시각화할 것인지가 매우 관심 받는 주제로 부각되고 있다. 이는 분석된 결과를 보다 명확하고 효과적으로 전달하는 데에 있어서 데이터의 시각화가 매우 효과적인 방법이기 때문이다. 시각화는 분석 시스템과 사용자가 소통하기 위한 하나의 그래픽 사용자 인터페이스(GUI)를 담당하는 역할을 한다. 통상적으로 이러한 GUI 부분은 데이터의 처리나 분석의 결과와 독립될 수록 시스템의 개발과 유지보수가 용이하며, MVC(Model-View-Controller)와 같은 디자인 패턴의 적용을 통해 GUI와 데이터 처리 및 관리 부분 간의 결합도를 최소화하는 것이 중요하다. 한편 빅데이터는 크게 정형 데이터와 비정형 데이터로 구분할 수 있는데 정형 데이터는 시각화가 상대적으로 용이한 반면, 비정형 데이터는 시각화를 구현하기가 복잡하고 다양하다. 그럼에도 불구하고 비정형 데이터에 대한 분석과 활용이 점점 더 확산됨에 따라, 기존의 전통적인 정형 데이터를 위한 시각화 도구들의 한계를 벗어나기 위해 각각의 시스템들의 목적에 따라 고유의 방식으로 시각화 시스템이 구축되는 현실에 직면해 있다. 더욱이나 현재 비정형 데이터 분석의 대상 중 대부분을 차지하고 있는 텍스트 데이터의 경우 언어 분석, 텍스트 마이닝, 소셜 네트워크 분석 등 적용 기술이 매우 다양하여 하나의 시스템에 적용된 시각화 기술을 다른 시스템에 적용하는 것이 용이하지 않다. 이는 현재의 텍스트 분석 결과에 대한 정보 모델이 서로 다른 시스템에 적용될 수 있도록 설계되지 못하는 경우가 많기 때문이다. 본 연구에서는 이러한 문제를 해결하기 위하여 다양한 텍스트 데이터 분석 사례와 시각화 사례들의 공통적 구성 요소들을 식별하여 표준화된 정보 모델인 텍스트 데이터 시각화 모델을 제시하고, 이를 통해 시각화의 GUI 부분과 연결할 수 있는 시스템 모델로서의 시각화 프레임워크인 TexVizu를 제안하고자 한다.

• International Journal of Aeronautical and Space Sciences
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• 제4권1호
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• pp.63-74
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• 2003

The vortical flow of a 65-deg flat plate delta wing with a leading edge extension(LEX) was examined through off-surface visualization, 5-hole probe and hot-film measurements. The off-surface flow visualization technique used micro water droplets generated by a home-style ultrasonic humidifier and a laser beam sheet. The angles of attack ranged from 10 to 30 degrees, and the sideslip angles ranged from 0 to -15 degrees. The Reynolds number was $1.82{\times}10^5$ for the flow visualization, and $1.76{\times}10^6$ for the 5-hole probe and hot-film measurements. The comparison of the visualization photos and the flow field measurement showed that the two results were in a good agreement for the relative position and the structure of the wing and LEX vortices, even though the flow Reynolds numbers of the two results were much different. The wing vortex and the LEX vortex coil each other while maintaining a comparable strength and identity at zero sideslip. Neither a looping of the wing vortex around the strake vortex, nor the lopsided coiling of the stronger strake and the weaker wing vortices was observed. At non-zero sideslip, the downward movement of the LEX vortex when going downstream was enhanced on the windward side, and the downward and inboard movement of the LEX vortex when going downstream was suppressed on the leeward side. The counterclockwise coiling of the wing and LEX vortices was decreased significantly on the leeward side.