• Journal of Electrical Engineering and Technology
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• v.1 no.2
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• pp.145-152
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• 2006

This paper presents a windows application for voltage sag analysis and effective data visualization. The developed Voltage Sag Analysis Tool (VSAT) was designed by using the Object-Oriented Programming (OOP) concept and C++ programming language. The VSAT provides basic functions for voltage sag analysis such as power flow analysis, short circuit analysis and stochastic analysis. In particular, the VSAT provides effective data visualization through computer graphics and animation. Analysis results are expressed realistically and intuitively on geographical display. The Graphic User Interface (GUI) of VSAT was designed specifically for voltage sag analysis. In this paper, the development and implementation of VSAT is presented. In order to demonstrate the capabilities of VSAT, it is used to analyze the Jeju Island power system in South Korea.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.2032-2041
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• 2004

Results from an experimental study of flow distribution in a close-coupled catalytic converter(CCC) are presented. The experiments were carried out with a flow measurement system specially designed for this study under steady and transient flow conditions. A pitot tube was a tool for measuring flow distribution at the exit of the first monolith. The flow distribution of the CCC was also measured by LDV system and flow visualization. Results from numerical analysis are also presented. Experimental results showed that the flow uniformity index decreases as flow Reynolds number increases. In steady flow conditions, the flow through each exhaust pipe made some flow concentrations on a specific region of the CCC inlet. The transient test results showed that the flow through each exhaust pipe in the engine firing order, interacted with each other to ensure that the flow distribution was uniform. The results of numerical analysis were qualitatively accepted with experimental results. They supported and helped explain the flow in the entry region of CCC.

• Journal of the Korean Society of Visualization
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• v.3 no.2
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• pp.45-50
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• 2005

Electro-osmotic flow (EOF) instability in a microchannel has been experimentally investigated using a micro-PIV system. The micro-PIV system consisting of a two-head Nd:Yag laser and cooled CCD camera was used to measure instantaneous velocity fields and vorticity contours of the EOF instability in a T-shape glass microchannel. The electrokinetic flow instability occurs in the presence of electric conductivity gradients. Charge accumulation at the interface of conductivity gradients leads to electric body forces, driving the coupled flow and electric field into an unstable dynamics. The threshold electric field above which the flow becomes unstable and rapid mixing occurs is about 1000V/cm. As the electric field increases, the flow pattern becomes unstable and vortical motion is enhanced. This kind of instability is a key factor limiting the robust performance of complex electrokinetic bio-analytical devices, but can also be used for rapid mixing and effective flow control fer micro-scale bio-chips.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.169-170
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• 2006

The main purpose of this study is to develop a program for sound field visualization system which gets noise signals in microphones array for incoming noise signals and it uses to operate noise signals and to store data in multi-channel FFT and is consisted to visualize noise signals with a image which is got by camera in center of array by using beamforming algorithm of the array signal processing.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.121-122
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• 2002

The main principle of radiation therapy is to deliver optimum dose to tumor to increase tumor cure probability while minimizing dose to critical normal structure to reduce complications. RTP system is required for proper dose plan in radiation therapy treatment. The main goal of this research is to develop dose model for photon, electron, and brachytherapy, and to display dose distribution on patient images with optimum process. The main items developed in this research includes: (l) user requirements and quality control; analysis of user requirement in RTP, networking between RTP and relevant equipment, quality control using phantom for clinical application (2) dose model in RTP; photon, electron, brachytherapy, modifying dose model (3) image processing and 3D visualization; 2D image processing, auto contouring, image reconstruction, 3D visualization (4) object modeling and graphic user interface; development of total software structure, step-by-step planning procedure, window design and user-interface. Our final product show strong capability for routine and advance RTP planning.

• 한국가시화정보학회:학술대회논문집
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• 2001.12a
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• pp.36-43
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• 2001

The flow field structures of two interacting parallel supersonic free jets are studied by flow visualization using planar laser-induced fluorescence of NO seeded in nitrogen gas. The experiments are carried out for several distances between two orifice centers and for various ratios of the pressure in the reservoir to that in the expansion chamber. The flow fields are visualized mainly on the plane including two jet centerlines and its characteristic shock system, especially a cell structure formed secondly by interaction of two jets, are analyzed. The positions of the normal shock depending on the pressure ratios are also compared.

• Journal of the Korean Society of Visualization
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• v.13 no.2
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• pp.16-21
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• 2015

Concentration polarization(CP) phenomena show great potential on desalination technology. As we can control the dimension of silicon based nanochannel system, it can be used to model ion exchange membrane. In this study, to investigate the effect of nanochannel number and working conditions on the CP based desalination process, nanochannel based microfluidic system is fabricated. First, we optimized nanochannel number and working conditions to conduct visualization study on CP based desalination process. Second, we visualized the desalination process with fluorescent dye in the desalination chip. We also visualized that the particles also can be removed by the CP based desalination process.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.712-714
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• 2005

Real-time 3D visualization of large datasets imposes a distributed architecture of the rendering system and dedicated hardware for image composition. Previous work on this domain has relied on prohibitively expensive cluster systems with hardware composition done by complicated schemes. In this paper we propose a low-cost hardware compositor fur a high performance visualization cluster. We show the system's design and the results obtained using Simulink [1] for our image composition scheme.

• Journal of the Korean Society of Visualization
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• v.6 no.1
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• pp.27-33
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• 2008

Air flow inside an automotive HVAC module has been investigated using a high-resolution PIV technique with varying the temperature operation mode. The PIV system consists of a 2-head Nd:YAG laser (125 mJ), a high-resolution CCD camera (2K$\times$2K), optics and a synchronizer. A real automotive HVAC module was used directly under real operating condition. Some casing parts of the HVAC module were replaced with transparent windows for capturing clear flow images with laser light sheet beam illumination. Time-averaged velocity fields were obtained for two different temperature control modes. Flow characteristics of the air-conditioned air flow inside the automotive HVAC system for the two temperature baffle conditions were evaluated.

• Journal of Korea Multimedia Society
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• v.18 no.1
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• pp.65-70
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• 2015

Particle accelerator has mainly used in nuclear field only because of the large scale of the facility. However, since laser-plasma particle accelerator which has smaller size and spends less cost developed, the availability of this accelerator is expended to various research fields such as industrial and medical. This paper suggests a visualization system to control the laser-plasma particle accelerator efficiently. This system offers real-time 3D images via convert HDF file comes from plasma data obtained from PIC simulation into OpenGL texture type to analyse and modify plasma data. After that, it stores high-resolution rendering images of the data with external renderer hereafter.