• Journal of Advanced Marine Engineering and Technology
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• v.21 no.3
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• pp.302-310
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• 1997

In this paper, we find a method to improve ignitability using methanol which is prospective as an alternative fuel. The constant volume combuster is divided into main chamber and sub-cham¬ber. These two chambers are linked by an adapter which is shaped like a cup. We also compare CDI to HIS that is revised in our laboratory for making a scrutiny into the effects of ignition char¬acteristics. Besides, we analyze a flame propagation process in the main and sub-chamber through taking pictures 10, 000 frames per second by high speed camera at the state being fabricated quartz glass aside main and sub-chamber.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1909-1914
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• 2003

Bubble growth on microheater has been experimentally investigated in this study. The experiment was performed using platinum micro heaters having dimensions of $100{\times}10{\times}0.2{\mu}m^3$ with constant heat flux. A high speed video camera was used to observe bubble growth at 250 frames per second. Microheater temperature was measured at the rate of 300Hz with a data acquisition system. When heater temperature was $139^{\circ}C$ a bubble was nucleated in the liquid FC-72. The temperature profiles and the high speed camera images were combined to explain heat transfer and bubble growth on microheater.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.351-355
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• 1999

The amount of data stored, processed and transmitted in the multi-media systems has been growing very fast, especially for the image data. For example, it takes 0.75Mbytes to store 512 12 pixels of 24-bit color image. A video signal with 30 frames per second will require 22.5Mbytes of storage space. To solve this problem, we need a good image compression technique. Recently, many researches on the image compression technique based on the wavelet transform are being pursued to overcome the problems of traditional JPEG. This paper describes the architecture and design of two-dimensional wavelet transform circuit. To keep the sire of the circuit small, we tried to minimize the internal storage space by using external SDRAM. This circuit was designed in Verilog-HDL, synthesized using Design Compiler and verified using Verilog-XL.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1003-1006
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• 1999

Hand segmentation and tracking is essential to the development of a hand gesture recognition system. This research features segementation and tracking of hand regions based the hue component of color. We propose a method that employs HSI color model, and segments and tracks hand regions using the hue component of color alone. In order to track the segmented hand regions, we only apply Kalman filter to a region of interest represented by a rectangle region. Initial experimental results show that the system accurately segments and tracks hand regions although it only uses the hue compoent of color. The system yields near real time throghput of 8 frames per second on a Pentium II 233MHz PC.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.824-828
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• 2007

With increasing interest in the reduction of cost for operation and maintenance of overhead catenary system, various methods of condition monitoring have been developed and used in with high-speed analysis and advanced image processing techniques. This study utilizes a high-speed camera as inspecting system to measure the wear, stagger, hight and arc extinguishing test of overhead catenary system. All measuring image were captured by a high speed CMOS camera with PCI express output, which can acquire up to 1000 frames per second with the resolution 1024 × 1280 pixels. Line type laser source with a power equal to 300 mW and the National Instrument LabVIEW (8.0) based on vision acquisition software have been used in application programming interface for image acquisition, display, and storage. The proposed high-speed camera system is finally applied to measure the overhead catenary system showing promising on-field applications

• Journal of the Korean Society of Visualization
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• v.11 no.3
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• pp.12-16
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• 2013

The impact and spreading behaviors of silicon dioxide nanoparticle colloidal suspension droplets were quantitatively visualized using a high-speed imaging system. Millimeter-scale droplets were generated by a syringe pump and a needle. Droplets of different velocity were impacted on a non-porous solid surface. Images were consecutively recorded using a CMOS high-speed camera at 5000 fps (frames per second) for millimeter-scale droplets. Temporal variations of droplet diameter, velocity and maximum spreading diameters were evaluated from the sequential images captured for each experimental condition. Effects of Reynolds number, Weber number, and particle concentration were investigated experimentally.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1960-1963
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• 2003

For applications such as video surveillance and human computer interface, we propose an efficiently integrated method to detect and track faces. Various visual cues are combined to the algorithm: motion, skin color, global appearance and facial pattern detection. The ICA (Independent Component Analysis)-SVM (Support Vector Machine based pattern detection is performed on the candidate region extracted by motion, color and global appearance information. Simultaneous execution of detection and short-term tracking also increases the rate and accuracy of detection. Experimental results show that our detection rate is 91％ with very few false alarms running at about 4 frames per second for 640 by 480 pixel images on a Pentium IV 1㎓.

• Journal of Mechanical Science and Technology
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• v.20 no.5
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• pp.692-709
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• 2006

Nucleate pool boiling experiments with constant wall temperature were performed using pure R1l3 for subcooled, saturated, and superheated pool conditions. A microscale heater array and Wheatstone bridge circuits were used to maintain the constant wall temperature and to measure the instantaneous heat flow rate accurately with high temporal and spatial resolutions. Images of bubble growth were taken at 5,000 frames per second using a high-speed CCD camera synchronized with the heat flow rate measurements. The bubble geometry was obtained from the captured bubble images. The effect of the pool conditions on the bubble growth behavior was analyzed using dimensionless parameters for the initial and thermal growth regions. The effect of the pool conditions on the heat flow rate behavior was also examined. This study will provide good experimental data with precise constant wall temperature boundary condition for such works.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1010-1015
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• 2003

Bubble growth on microheater has been experimentally investigated in this study. The experiment was performed using platinum microheaters having dimensions of 300 ${\mu}m$ or 50 ${\mu}m$ in length, 20 ${\mu}m$ or 5 ${\mu}m$ in width, and $0.2{\pm}0.01$ ${\mu}m$ in thickness. A high speed video camera was used to observe bubble growth at 2,000 frames per second. Microheater temperature was measured at the rate of 300 Hz. with a data acquisition system. Bubble nucleation frequency increased with working fluid temperature. Although the slope of temperature drop was similar in all cases, the magnitude of temperature drop was different. The temperature profiles and the high speed camera images were combined to explain temperature drop.

• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.46-52
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• 2011

In this paper, the swept source-optical coherence tomography system using frequency domain mode locked(FDML) laser has realized. The FDML swept source laser showed 55.03 kHz sweeping speed, 125 nm sweeping range, and 9 mW output optical power, which are the superiority of FDML laser compared to previous swept source lasers. Also, through the cross-sectional image captured at 5 frames per second for a mirror, a 1 mm-thickness glass plate, and a thumb bottom, the performance of the system has demonstrated.