• Korean Journal of Computational Design and Engineering
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• v.12 no.6
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• pp.413-421
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• 2007

3D rendering is becoming a common feature of mobile application programs with the rapid advance of mobile devices. Since the existing rendering engines do not provide triangulation functions, mobile 3D programs have focused on an efficient handling with pre-tessellated geometry. In addition, triangulation is comparatively expensive in computation, so it seems that the triangulation cannot be easily implemented on mobile devices with limited resources. Triangulation of 3D geometry is the essential process of visualization of 3D model data and many different triangulation methods have been reported. We developed a light and fast visualization process that involves constrained triangulation based on Voronoi diagram and applied it to a mobile computer application. In this paper, we applied kd-tree to the original incremental construction algorithm and produced new O(nlogn) incremental construction algorithm. And we show a simple and efficient constrained triangulation method based on Voronoi diagram. This paper also describes an implementation of mobile STEP data viewer as an application of our proposed algorithms.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.69-70
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• 2007

• Current Optics and Photonics
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• v.4 no.6
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• pp.516-523
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• 2020

The normal low-cost manufacturing process for freeform vehicle side mirrors causes deviations from the design curvature. Here, an improved manufacturing process is proposed, combining photorealistic ray-traced visualization of each deviation and subsequent analysis of its deviated reflective scene compared to that of the original design. The proposed mechanism successfully highlights the overlap and mismatch regions of deviated reflected scenes with reference to the desired reflective scenes. We benchmarked the robustness of freeform mirror manufacturing by evaluating the 10, 20, and 30% root-mean-square (RMS) deviated curvature, and concluded that the acceptable deviation needs to be below RMS20% to avoid mismatched regions that could mislead the driver.

• Educational Technology International
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• v.7 no.1
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• pp.21-37
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• 2006

This paper focuses on finding out visualization process by means of VTA(Visual Task Analysis) of expert teachers' simple task. Findings indicate teachers have coding schema of performing visual task as such; (a) the analyzing by reading and some activities in the task text, (b) conceptualizing or understanding in his/her own way, (c) the explaining of the action or product, (d) the searching by thinking or finding, (e) the decision of visualizing of the task. Expert teachers tried to visualize in the form of abstract graph, and to omit the object which was not directly related to the topic at the pilot study. VAT based on ground theory and protocol analysis was developed and performed. This case study suggests that an additional study for searching a guide and method might be beneficial for conducting a visual task analysis.

• Journal of the Korean Society of Visualization
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• v.14 no.3
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• pp.32-37
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• 2016

In this study, the mixing process of two distinct flow is numerically investigated. Two flow with different physical properties (resin and hardener) are mixed through the opposing mixing jets. At a high pressure mixing process, the high speed flow is provided by two in-line nozzles. In the case of numerical modeling, Reynolds-Averaged Navier-Stokes Equations (RANS) is conducted to model the flow pattern inside the chamber. Additionally, SST k-omega turbulence model is selected to predict the kinetic energy of flow in impingement zone. The results show that mixing of two distinct flows would be efficient if the velocity of jet is high enough and nozzle diameter is a predominant parameter. Also, this velocity would create higher shear stress between two distinct flows which increases the mixing quality as well as strength of formed vortices. Eventually, the histogram of concentration fraction of resin is examined in order to show the quality of mixing and the range of concentration fractions in the output of chamber.

• Spatial Information Research
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• v.23 no.6
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• pp.109-116
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• 2015

In this study, define the concept of spatial big data and special feature of spatial big data, examine information visualization methodology for increase the insight into the data. Also presented problems and solutions in the visualization process. Spatial big data is defined as a result of quantitative expansion from spatial information and qualitative expansion from big data. Characteristics of spatial big data id defined as 6V (Volume, Variety, Velocity, Value, Veracity, Visualization), As the utilization and service aspects of spatial big data at issue, visualization of spatial big data has received attention for provide insight into the spatial big data to improve the data value. Methods of information visualization is organized in a variety of ways through Matthias, Ben, information design textbook, etc, but visualization of the spatial big data will go through the process of organizing data in the target because of the vast amounts of raw data, need to extract information from data for want delivered to user. The extracted information is used efficient visual representation of the characteristic, The large amounts of data representing visually can not provide accurate information to user, need to data reduction methods such as filtering, sampling, data binning, clustering.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.10
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• pp.1146-1152
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• 2011

Ink transfer process is very important to determine quality of printed pattern, therefore its mechanism should be understood to control printing quality. Although there have been many attempts to understand ink transfer mechanism by numerical simulation and experimental studies, their model was too much simple to model realistic printing process and our understanding is not enough yet. In this paper we designed ink transfer visualization system to present flow visualization of ink transfer process for gravure offset printing. We considered rotational effect of blanket roll which is related with printing speed and used non-Newtonian fluid as working fluid such as Ag paste. For printing unit, cantilever-type blanket roll is used for convenient visualization of ink transfer. Serial images were captured continuously by using high-speed CMOS camera and long range microscope. We investigated the effects of various design parameters such as printing speed and pattern angle on the ink transfer process. We found more stretched ink filament for non-Newtonian fluid than Newtonian fluid. As increasing printing speed, length of stretched ink filament and height of break-up point are also increased. We also compared ink transfer process between CD and MD pattern and its relationship with ink transfer mechanism.

• Journal of Korea Multimedia Society
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• v.6 no.2
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• pp.332-339
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• 2003

To solve the large scale optimization problem approximately, various approaches have been introduced. Recently the Particle Swarm Optimization has been introduced. The Particle Swarm Optimization simulates the process of birds flocking or fish schooling for food, as with the information of each agent is skated by other agents. The Particle Swarm Optimization technique has been applied to various optimization problems whose variables are continuous. However, there are seldom trials for visualization of searching process. This paper proposes a new visualization tool for searching process of Particle Swarm Optimization algorithm. The proposed tool is effective for understanding the searching process of Particle Swarm Optimization method and educational for students. The computational results can be shown tiny and very helpful for education.

• Journal of the Korean Society of Visualization
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• v.1 no.2
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• pp.13-16
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• 2003

LSPIV(Large Scale Particle Image Velocimetry) is widely used in the field of civil and environmental engineering. General aspects of LSPIV are introduced and several applications are introduced in this paper. The difference of LSPIV from the conventional PIV techniques is not to use models for experiments but to use the flow fields in nature. For LSPIV a converting process for the captured images is necessary.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.04a
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• pp.327-330
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• 2003

In this study a framework for cost effective visualization application is presented. Visualizations of a complex street rehabilitation and a highway interchange project are performed. The visualized products were presented to political and community groups, which significantly expedited the consensus building and project approval process.