• Journal of Information Technology Applications and Management
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• 제14권4호
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• pp.75-96
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• 2007

The effects of information quality and the importance of information have been reported in the Information Systems (IS) literature. However, little has been learned about the impact of information visualization types and contextual information on decision quality. Therefore, this study investigated the interaction effects of these variables on decision quality by conducting a laboratory experiment. Based on two types of information visualization and the availableness of contextual information, this study had a $2{\times}2$ factorial design. The dependent variables used to measure the outcomes of decision quality were decision accuracy and time. The results demonstrated that the effects of contextual information on decision quality were significant. In addition, there was a significant main effect of information visualization on decision accuracy. The findings suggest that decision makers can expect to improve their decision quality by enhancing information visualization types and contextual information. This research may extend a body of research examining the effects of factors that can be tied to human decision-making performance.

• 한국가시화정보학회지
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• 제4권2호
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• pp.51-58
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• 2006

A boundary layer visualization was carried out in order to investigate the influence of Reynolds number on an oscillating airfoil. An NACA 0012 airfoil is sinusoidally pitched at the quarter chord point with oscillation amplitude of ${\pm}6^{\circ}$. A smoke-wire technique was employed to visualize the boundary layer and the near-wake. The freestream velocities are 1.98, 2.83 and 4.03m/s and corresponding chord Reynolds numbers are $2.3{\times}10^4,\;3.3{\times}10^4$, and $4.8{\times}10^4$, respectively. As the reduced frequency of K=0.1 is fixed, the corresponding frequency of an airfoil was adjusted in each case. The results reveal that the point at which the shear stress in an unsteady boundary layer separation disappears does not correspond with the position of the breakdown of the boundary layer, and that the breakdown of the boundary layer occurs further downstream.

• Journal of Information Processing Systems
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• 제4권2호
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• pp.61-66
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• 2008

In recent years, numerous studies have been attempted to exploit ontology in the area of ubiquitous computing. Especially, some kinds of ontologies written in OWL are proposed for major issues in ubiquitous computing such like context-awareness. OWL is recommended by W3C as a descriptive language for representing ontology with rich vocabularies. However, developers struggle to design ontology using OWL, because of the complex syntax of OWL. The research for OWL visualization aims to overcome this problem, but most of the existing approaches unfortunately do not provide efficient interface to visualize OWL ontology. Moreover, as the size of ontology grows bigger, each class and relation are difficult to represent on the editing window due to the small size limitation of screen. In this paper, we present OWL visualization scheme that supports class information in detail. This scheme is based on concept of social network, and we implement OWL visualization plug-in on $Prot{\acute{e}}g{\acute{e}}$ that is the most famous ontology editor.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2004년도 추계학술대회 논문집
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• pp.68-71
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• 2004

The experiments for NACA airfoils are conducted as the preliminary study for the aerodynamic characteristics of the transonic airfoil flow in the shock tube. The test section configurations were designed to use shock tube as simple and less costly experimental facility generating transonic flow at relatively high Reynolds numbers. Experiments at hot gas Mach numbers of 0.80, 0.82 and 0.84, Reynolds numbers of about $1.2\times10^6$ on airfoil chord length and angle of attack of $0^{\circ}\;and\;2^{\circ}$ were carried out by means of shadowgraph visualization method and static pressure measurements. Visualization results were compared with the corresponding results from the conventional transonic wind tunnel tests. The results of study showed that present shock tube facility is useful to study the proper performance characteristics in transonic Mach number range.

• 한국실내디자인학회논문집
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• 제37호
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• pp.110-118
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• 2003

Computer simulation is one of the most useful techniques to predict daylighting performance and present visual image. In architectural and interior design practice, the Lightscape is commonly used often to produce persuasive images rather than physically accurate results. Therefore, this study is to validity the Lightscape as daylighting evaluation tool, in particularly performance and realistically visualization. For the purpose, an evaluation test model (12.0m$\times$7.2m$\times$3.0m) of side lighting window with lightshelf was selected. A 1:6 scale plywood physical model was made. Under clear sky condition, illuminance of 84 Interior point were measured. Lightscape was run on a 750 MHz Pentium PC running Windows 2000 under the same sky condition. And a photography image was compared to rendering image. The physical results of interior illuminance were within 8% between the scale model and Lightscape simulation. There were no differences between the photograph image and rendering image by Lightscape in the sight. Lightscape as visualization tool for daylighting performance was validated.

• 한국가시화정보학회지
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• 제7권2호
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• pp.28-34
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• 2010

Two turbulent jet with different sinusoidal nozzle exit configurations of in-phase and $180^{\circ}$ out-of-phase were investigated experimentally using a smoke-wire method and a hot-wire anemometry. Mean velocity and turbulence intensity were measured at several downstream locations under $Re_D\;=\;5000$. For the case of in-phase nozzle configuration, the length of potential core exhibits negligible difference with respect to the transverse locations (0, $\lambda/4$ and $\lambda/2$), similar to that of a plane jet. On the other hand, a maximum difference of 30% in the potential-core length occurs for the $180^{\circ}$ out-of-phase configuration. The spatial distributions of turbulence intensities also show significant difference for the nozzle of $180^{\circ}$ out-of-phase, whereas non-symmetric distribution is observed in the near-exit region(x/D = 1) for the in-phase sinusoidal nozzle jet. Compared to a slit planc jet, the sinusoidal nozzle jets seem to suppress the velocity deficit as the flow goes downstream. The sinusoidal nozzle jet was found to decrease turbulent intensity dramatically. The flow visualization results show that the flow characteristics of the sinusoidal nozzle jet are quite different from those of the slit plane jet.

• 대한수학교육학회지:학교수학
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• 제14권1호
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• pp.1-28
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• 2012

본 연구는 30명의 고등학교 2학년 학생들을 통해서 수학적 시각화의 구성 요소를 알아보고, 시각화 구성 요소들이 수학 문제 해결 과정에서 어떻게 활용되는지를 알아보는 것이다. 특히, 30명의 학생들 중 시각성 평가가 높은 5명의 학생들에 대해서 질적 사례 연구를 실시하였다. 분석 결과를 보면, 시각화의 구성 요소는 크게 정신적 이미지, 외적 표상, 이미지의 변형 및 조작, 공간 시각화 능력으로 범주화 (Guti$\acute{e}$rrez, 1996) 되었고, 각 요소마다 더 세분화되어져 나타났다. 또한, 수학 문제 해결 과정에서 시각화 요소들은 외적 표상을 생성하기 전에 기본적으로 정신적 이미지를 생성하고 있었고, 정형화된 정신적 이미지의 경우 문제 해결에 대한 학생들의 풍부한 사고를 억제하고 문제에 대한 부적절한 풀이 결과를 이끌어낼 수 있는 부정적인 영향을 주었다. 차원 변화에 의해서 이루어지는 이미지 변형 및 조작을 어려워하는 학생들이 있었으나, 문제 해결 과정에서 답을 추론하기 위한 이미지 탐색 활동과 도출된 답의 정당화를 위해서 이미지 조작 활동을 활용하고 있었다.

• 한국가시화정보학회지
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• 제12권1호
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• pp.43-48
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• 2014

This paper describes the measurement of performance evaluation of rotational flow varying chamber size and Reynolds number. Through the experimental visualization of the flow rotation, the number and position of flow rotation in the $2{\times}2$ microfluidic centrifuge were examined. At a chamber width of 250${\mu}m$, single flow rotation was obtained over at a Reynolds number of 300, while at a chamber width of 500 ${\mu}m$, single flow rotation did not appear. For performance evaluation, the intensity in microchamber was measured during 20 sec. At a chamber width of 250 ${\mu}m$, performance of rotational flow increased as Reynolds number increased. However, the variation of intensity in microchamber remained unchanged at a chamber width of 500 ${\mu}m$. The numerical analysis showed that the threshold centrifugal acceleration to obtain rotational flow for ejected particles was 200g.

• 대한핵의학회지
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• 제2권1호
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• pp.21-25
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• 1968

Radiographic visualization of the pancreas is a difficult problem, but the direct visualization of the pancreas is possible by the injection of the amino-acid methionine tagged with $selenium^{75}$75 ($Se^{75}$). In order to know the diagnostic value of pancreas scanning, scans were performed on 23 cases using $selenium^{75}$-selenomethionine. These cases were also given egg white, probanthine and morphine. 1. Good visualization of the pancreas scanning was observed on 19 cases, presumably with normal pancreas. 2. A case which showed diffusely decreased uptake on pancreas scanning was proven to have lesions in the bile duct and the gall bladder. 3. Of those two cases which showed localized cold area, one had pancreas cyst and the other one was not explored. 4. A case which showed no visualization of the pancreas was proven to have pancreatic carcinoma. 5. Two cases which showed widened duodenal loop by upper gastro-intestinal series revealed normal pancreas scanning, and no pancreatic disease was found in both cases.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2005년도 추계학술대회 논문집
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• pp.50-53
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• 2005

The turbulent flow around a sphere was investigated in a streamwise meridian plane using two experimental techniques: smoke-wire flow visualization in wind tunnel at Re=5,300 and PIV measurements in a circulating water channel at Re=7,400. The smoke-wire visualization shows flow separation points near an azimuthal angle of $90^{\circ}$, recirculating flow, transition from laminar to turbulent shear layer, evolving vortex roll-up and fully turbulent eddies in the sphere wake. In addition, the mean flow pattern extracted by particle tracing method in water tunnel at Re= 14,500 reveals two distinct comparable toroidal(not closed) vortices in the recirculation region. The mean velocity field measured using a PIV technique demonstrates the detailed wake configuration of close symmetric recirculation and near-wake configuration with two toroidal vortices, reversed velocity zone and vorticity contours.