• Proceedings of the Korea Database Society Conference
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• 2008.05a
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• pp.211-224
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• 2008

As a lot of information and media are given to users in Internet space nowadays, users feel disoriented or "lost in space" intensively. So it is suggested that we have the system to reduce information overload and to propose effective and efficient information. In this study we present a visualizing technique which uses fisheye views on data adjacency to combine global context and local details for presentation of many results in limited space. Data Adjacency on graph theory is applied to set up degree of interest which is main focus in fisheye views. Graph theory is useful to solve the problem resulted from various combinational optimization, especially it has advantages to analyze issues in information space like Internet. To test the usability of the proposed visualization technique, we compared the effectiveness of different visualization techniques. Results show that our method is evaluated with respect to less time and high satisfaction for a task accomplishment.

• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.117-120
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• 2002

An experimental research has been carried out for flow control of the shock wave/turbulent boundary-layer interaction utilizing aeroelastic mesoflaps. Various shapes and thicknesses of the mesoflap are tested to achieve different deflections of the flap, and ail the results are compared to the solid-wall reference case without flow-control mechanism. Quantitative variation of skin friction has been measured downstream of the interactions using the laser interferometer skin friction meter, and qualitative skin friction distribution has been obtained by observing the interference fringe pattern on the oil-film surface. A strong spanwise variation in the fringe patterns with a narrow region of separation near the centerline is noticed to form behind the shock structure, which phenomenon is presumed partially related to three-dimensional flow structures associated with both the sidewalls and the bottom test surface. The effect of the shape of the cavity is also observed and it is noticed that the shape of the cavity is not negligible.

• Journal of the Korean Society of Visualization
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• v.16 no.3
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• pp.35-39
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• 2018

In multiphase systems, surface wettability is one of dominant design parameters to enhance system performance. Since surface wettability can be maximized and minimized with micro-textured surfaces, therefore micro-textured surfaces are widely countered in various research and engineering fields. In this study, for better understanding of micrometer scaled surface wettability, spreading phenomena is experimentally investigated on the hydrophilic micro-textured surfaces. By photolithography and conventional dry etching method, there are prepared the surfaces with uniformly arrayed micro-pillars. The interfacial motions of a water droplet on the test sections are visualized by high speed camera in top view. On the basis of visualization data, it is analyzed the relation between dynamic coefficient and geometrical features on micro-textured surfaces.

• Journal of the HCI Society of Korea
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• v.12 no.1
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• pp.5-13
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• 2017

Interactive intervention of the human presenter is one of the important factors that make the visualization more effective. Rather than just showing the content, the presenter enhances the process of the information delivery by providing the context of visualization. In this paper, we define this as an augmented presentation. In augmented presentation concept, the presenter can facilitate presentation more actively by being fully immersed in the visualization space and reaching and interacting into digital information. In order to concrete the concept, we design presentation space that enables the presenter to be seamlessly immersed in the visualization. Also we increase the presenter's roles as a storyteller, controller and augmenter allowing the presenter to fully support communicative process between the audience and the visualization. Then, we present an augmented presentation system to verify the proposed concept. We rendered 3D visualization through a half-mirror film and a wall projection screen that are place in parallel and applied with stereoscopic images, then, spatially align the presenter inside the virtual visualization space. After that, we conduct a controlled experiment to investigate the subjective level of immersion and engagement of the audience to HoloStation compared to traditional presentation system. Our initial investigation suggests that the newly conceived augmented presentation has potential not only to enhance the information presentation but also to supports the delivery of visualization.

• Journal of The Korean Association of Information Education
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• v.26 no.6
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• pp.481-490
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• 2022

With the development of computing technology, the big data era has arrived, and we live with a lot of data around us. Elementary school students are no exception. Therefore, it is very important to learn to process data from elementary school. Since elementary school students have intuitive thinking, data visualization, which expresses data directly in pictures, is an important learning element. In this study, we study how effective elementary school students can visualize data in their daily lives to improve their information processing capabilities. Adata visualization program was developed by organizing and visualizing data using data visualization tools for the 8th class, which can be done by third graders in elementary school, and then experiencing the process of interaction. As a result of applying the developed program to 186 students in 7 classes, knowledge information processing competency factors were evaluated before and after class. As a result of the pre- and post-test, there was a significant difference in knowledge information processing capabilities. Therefore, the data visualization program developed in this study is effective.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.129-137
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• 2006

This paper studies the effects of the swirl for the variation of intake port configuration that is key parameters in the flow field of direct injection diesel engines. In-cylinder flow characteristics is known to have significant effects on air-fuel mixing, combustion, and emissions. To investigate the effects of the swirl flow, various rpm(250, 500, 750) and two different intake port were used. And to evaluate the swirl motion in the flow field visualization engine, steady state flow test was conducted. Helical port intake port and SCV(Swirl Control Valve) were selected as the design parameters to increase the swirl flow and parametric study was performed. In the case of non-SCV, intake flow rate and non-dimensional swirl ratio were higher than those of SCV for the swirl head type. So, we could strengthen the swirl in the flow field with the swirl head type and don't using SCV. From the results of steady state flow test, non-swirl head type has the most good advantage for intake flow rate, and also the flow rate could be increased by using the SCV slightly. The effects of the type of engine head on intake air flow capability are dominant with respect to the existence of the SCV. We could measure the qualitative grade of swirl by capturing the scattering signal of microballoon from ICCD camera in the visualization diesel engine.

• Journal of Korean Elementary Science Education
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• v.36 no.1
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• pp.73-84
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• 2017

Cultivating creativity is one of the goals in science education. Previous studies report that students use visualization while they solve the creative science problem and it looks helpful to make them think more. For this study three $6^{th}$ grade students were selected in the consideration of pre-test through the qualitative think-aloud method. The results show that even though students have many ideas in planning stage in problem solving, they appeared to visualize familiar and empirical ideas at first. So if teachers want to watch another creative ideas, they tended to give enough time to visualize many ideas. Students drew lines, circles, "X"marks to select or remove information during their problem solving works. They said these marks seem to be useful to understand question. However, removal marks sometimes turn out to block another chance to re-think. Also students did not have a chance to reflect what they did. It means that they lose the chance to do convergent thinking. The implications of this study include the importance of students' visualization works to facilitate their creative ideas and support their problem solving strategies. In this study, we discuss the meaningful messages for teachers who construct science classroom for creativity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.8
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• pp.772-779
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• 2005

An efficiency of a refrigeration cycle and a reliability of a compressor can be reduced if a refrigerant including excessive lubricating oil is exhausted from the compressor. Thus, the analysis of the oil behavior inside the compressor is required to prevent the problem. A tested rotary compressor with visualization windows has been manufactured in this study to investigate the oil behavior using developed visualization techniques. The oil behaviors at various operating conditions have been quantified to obtain the relationship with the outlet pressure inside the compressor. Also, the effect of the operating conditions on the quantity of the exhausted oil from the rotary compressor has been investigated using a manufactured test model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.8
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• pp.84-93
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• 2010

This paper describes a method of visualization and fast estimation of parameter in continuous time signal. The parameter estimation method of this paper directly estimate the parameters on the basis of the discrete Fourier transform. Also, this paper present to efficient visualization method of dominant parameters obtained in continuous time signal. The proposed methods are applied to test functions with three dominant modes. The results show that the proposed methods are highly applicable to parameter estimation and visualization in continuous time signal.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.19-25
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• 2008

Selective Catalytic Reduction is effective in the reduction of NOx emission. This research focused to evaluate the performance of a urea-SCR system and was conducted in two procedures. One is SCR reactor test using model gas in order to provide an optimal injection condition itself. In this step, some parametric study on emission temperature, space velocity, aspect ratio and the formation of urea spray were made by using flow visualization and Computation Fluid Dynamics techniques. The basic simulation results contributed in determining the layout for an actual engine test. The other is an engine performance and emission test. The urea injector was placed at the opposite direction of exhaust gases emitted into an exhaust duct and an optimal amount of a reducing agent is estimated accurately under different engine loads and speeds. Furthermore, the variation of NOx emission and applied amount of urea was investigated in terms of modes under the condition of with and without SCR, and other emissions such as PM, CO and NMHC were evaluated quantitatively as well. This research may provide fundamental data for the practical use of urea-SCR in future.