• Journal of the Korean Society of Visualization
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• v.9 no.4
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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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• 2003.11a
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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.

• Journal of the Korean Society of Visualization
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• v.2 no.2
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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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• 2002.11a
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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.

• The Korean Journal of Nuclear Medicine
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• v.13 no.1_2
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• pp.15-21
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• 1979

From January 1975 to March 1978, 18 cases of chronic myelogenous leukemia diagnosed at Kyungpook National University Hospital were tested by hepatosplenic scanning with $^{198}Au$ colloidal gold. The photo scanning findings in relation to clinical and laboratory findings are following. 1) Male to female ratio was 2:1 and 2nd and 3rd decades were predominant. 2) No focal space-occupying lesion was noticed both in the liver and spleen. 3) 4 cases revealed well visualization of spleen, 7 cases poor visualization, and 7 cases nonvisualization. 4) No significant difference between well visualization group and poor visualization group was noted in clinical findings, liver function test and hematologic findings. 5) Cases with nonvisualization of the spleen tended to be associated with thrombocytopenia, decreased megakaryocytes in the marrow and longer duration of the illness.

• The Korean Journal of Nuclear Medicine
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• v.5 no.1
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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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• v.32 no.7
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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.

• Proceedings of the KSME Conference
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• 2004.04a
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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.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.39-58
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• 2014

As the importance of big data and related technologies continues to grow in the industry, it has become highlighted to visualize results of processing and analyzing big data. Visualization of data delivers people effectiveness and clarity for understanding the result of analyzing. By the way, visualization has a role as the GUI (Graphical User Interface) that supports communications between people and analysis systems. Usually to make development and maintenance easier, these GUI parts should be loosely coupled from the parts of processing and analyzing data. And also to implement a loosely coupled architecture, it is necessary to adopt design patterns such as MVC (Model-View-Controller) which is designed for minimizing coupling between UI part and data processing part. On the other hand, big data can be classified as structured data and unstructured data. The visualization of structured data is relatively easy to unstructured data. For all that, as it has been spread out that the people utilize and analyze unstructured data, they usually develop the visualization system only for each project to overcome the limitation traditional visualization system for structured data. Furthermore, for text data which covers a huge part of unstructured data, visualization of data is more difficult. It results from the complexity of technology for analyzing text data as like linguistic analysis, text mining, social network analysis, and so on. And also those technologies are not standardized. This situation makes it more difficult to reuse the visualization system of a project to other projects. We assume that the reason is lack of commonality design of visualization system considering to expanse it to other system. In our research, we suggest a common information model for visualizing text data and propose a comprehensive and reusable framework, TexVizu, for visualizing text data. At first, we survey representative researches in text visualization era. And also we identify common elements for text visualization and common patterns among various cases of its. And then we review and analyze elements and patterns with three different viewpoints as structural viewpoint, interactive viewpoint, and semantic viewpoint. And then we design an integrated model of text data which represent elements for visualization. The structural viewpoint is for identifying structural element from various text documents as like title, author, body, and so on. The interactive viewpoint is for identifying the types of relations and interactions between text documents as like post, comment, reply and so on. The semantic viewpoint is for identifying semantic elements which extracted from analyzing text data linguistically and are represented as tags for classifying types of entity as like people, place or location, time, event and so on. After then we extract and choose common requirements for visualizing text data. The requirements are categorized as four types which are structure information, content information, relation information, trend information. Each type of requirements comprised with required visualization techniques, data and goal (what to know). These requirements are common and key requirement for design a framework which keep that a visualization system are loosely coupled from data processing or analyzing system. Finally we designed a common text visualization framework, TexVizu which is reusable and expansible for various visualization projects by collaborating with various Text Data Loader and Analytical Text Data Visualizer via common interfaces as like ITextDataLoader and IATDProvider. And also TexVisu is comprised with Analytical Text Data Model, Analytical Text Data Storage and Analytical Text Data Controller. In this framework, external components are the specifications of required interfaces for collaborating with this framework. As an experiment, we also adopt this framework into two text visualization systems as like a social opinion mining system and an online news analysis system.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.1
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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.