• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.130-132
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• 2012

The use of visual media has been increased by development of contemporary society. To use these information of image, there are various methods of image processing. Edge detection which is one of those is technique to detect dramatically changing part of image brightness. Existing methods detect edge through mask which is composited by constant values. Because existing methods do not consider factor as location, direction of pixel in image, performance of edge detecting in insufficient. Therefore, an algorithm which is using variable vector for the variation of brightness in mask of $3{\times}3$ pixels is proposed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.153-157
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• 2009

A Highly efficient Mercury-free Flat Fluorescent Lamp (MFFL) with dielectric barrier Xe gas discharge was developed for an alternative of conventional line-type Cold Cathode Fluorescent Lamps (CCFLs) which shows a wide voltage margin and a stable discharge operation for diffuse glow discharge with an application of a auxiliary electrode. Electro-optic characteristics of the MFFL were examined through the changes in ambient temperature, total pressure and Xe partial pressure. the single cell is expanded into a multi-structured configuration to realize a large sized lamp by a simple repetition of the single cells, and a new driving scheme is proposed for an adaptive brightness control using dual auxiliary electrodes and bi-polar drive scheme. In addition, interesting application of this ultra high luminance flat lamp by the optimization of the gas condition and the pattern of the rear phosphor layer is suggested as a good alternative of daylight lamp source

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.197-200
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• 2007

Edge representing the boundary between two regions with the large brightness difference in image includes diverse information about object. Therefore, this information has been utilized in fields such as image segmentation and object recognition. There are many kinds of edge in according to duration time and the amplitude of brightness variation, and edge is generally detected through the differential. Recently, in fields of image processing and computer vision, edge detection methods have been proposed to use in specific applications. Hence, in this paper the wavelet function for improved edge detection properties was proposed and detected line-edge components of images and its performance was proven through simulations.

• Journal of Sensor Science and Technology
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• v.20 no.3
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• pp.178-186
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• 2011

Line tracking is a well defined method of mobile robot navigation. It is simple in concept, technically easy to implement, and already employed in many industrial sites. Among several different line tracking methods, magnetic sensing is widely used in practice. In comparison, vision-based tracking is less popular due mainly to its sensitivity to surrounding conditions such as brightness and floor characteristics although vision is the most powerful robotic sensing capability. In this paper, a vision-based robust path line detection technique is proposed for the navigation of a mobile robot assuming uncontrollable surrounding conditions. The technique proposed has four processing steps; color space transformation, pixel-level line sensing, block-level line sensing, and robot navigation control. This technique effectively uses hue and saturation color values in the line sensing so to be insensitive to the brightness variation. Line finding in block-level makes not only the technique immune from the error of line pixel detection but also the robot control easy. The proposed technique was tested with a real mobile robot and proved its effectiveness.

• Journal of the Korean Society of Safety
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• v.21 no.5 s.77
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• pp.6-11
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• 2006

This study aims to measure a smoke density and velocity by using the PIV method in case a fire occurs in tunnels. By doing so, this will estimate a critical velocity, examine its appropriateness, and present the basic materials necessary for designing a smoke control equipment. For this study, a visualization test was conducted based on the 1/20 miniature of a real tunnel according to the Froude scaling. As a part of basic experiments, a correlation between smoke density and brightness was analyzed here, and a critical velocity was estimated on the condition that a fire breaks out in tunnels. As a result, this study finds that there is a correlation between smoke density and brightness within a range of 100% to 30% transmittance, from which a quantitative smoke density can be obtained. The study also suggests that a critical velocity calculated from the Kennedy formula shows about 10% difference from that estimated in the test.

• Journal of Fashion Business
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• v.25 no.2
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• pp.51-62
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• 2021

This study evaluated the cosmetic effects of a far-infrared hot and cool mask (BBSkinplus) on face skin moisturization, whitening, and wrinkles using a randomized clinical trial. Forty female participants (mean age 47.7 ± 4.6 years) were allocated into the treatment group (BBSkinplus treatment and lotion application twice a day) or the control group (only lotion application twice a day), and moisture, brightness, and wrinkles were measured at 0, 1 and 2 weeks. The average values of each measurement were changed significantly by BBSkinplus treatment compared to the control group. At the 2-week treatment time point, the statistical differences in improvement rates between the two groups were significant at 8.7% vs. 3.9% for moisture (p < 0.01), 0.7% vs. 0.4% for brightness (p < 0.01), and -3.1% vs. 0.0% as Ra and -6.3% vs. 1.5% as R3z for wrinkles (p < 0.05), respectively. No notable complaint was reported regarding any kind of adverse effects such as erythema, itching, or burning. This clinical data support the potential of BBSkinplus as a home beauty device providing moisturizing, whitening, and anti-wrinkle effects on the face.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2082-2084
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• 1998

This paper presents a microcontroller-based electronic neon ballasts which is highly suitable for a multi-use and low power consumption by performing economical hardwares and variable software algorithms. Result of this study has the following functions : brightness control, frequency variable output, automatic lightening control, low power characteristics.

• Korean Journal of Cognitive Science
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• v.16 no.4
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• pp.305-322
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• 2005

Watermarking is a widely employed method tn protecting copyright of a digital image, the owner's unique image is embedded into the original image. Strengthened level of watermark insertion would help enhance its resilience in the process of extraction even from various distortions of transformation on the image size or resolution. However, its level, at the same time, should be moderated enough not to reach human visibility. Finding a balance between these two is crucial in watermarking. For the algorithm for watermarking, the predefined strength of a watermark, computed from the physical difference between the original and embedded images, is applied to all images uniformal. The mean brightness or contrast of the surrounding images, other than the absolute brightness of an object, could affect human sensitivity for object detection. In the present study, we examined whether the detectability for watermark noise might be attired by image statistics: mean brightness and contrast of the image. As the first step to examine their effect, we made rune fundamental images with varied brightness and control of the original image. For each fundamental image, detectability for watermark noise was measured. The results showed that the strength ot watermark node for detection increased as tile brightness and contrast of the fundamental image were increased. We have fitted the data to a regression line which can be used to estimate the strength of watermark of a given image with a certain brightness and contrast. Although we need to take other required factors into consideration in directly applying this formula to actual watermarking algorithm, an adaptive watermarking algorithm could be built on this formula with image statistics, such as brightness and contrast.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.104-110
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• 2011

High-brightness LED control is required for stable operation, thus the driver and control system must be designed to deliver a constant current to optimize reliability and ensure consistent luminous flux. In this paper, the sliding mode current controller is designed to adjust the illumination density of power LEDs. The controller design model of power LEDs, including its driving circuit, is proposed to realize the dimming control of power LEDs. A buck converter is introduced to drive the power LEDs and reduce the input voltage to a lower level. The sliding mode software controller is implemented to adjust the dimming of power LEDs. The proposed strategy for driving power LEDs is investigated and comparatively studied by experiments.

• Journal of Industrial Technology
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• v.29 no.B
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• pp.133-137
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• 2009

This paper presents the development of smart road line lamp system consisting light control device. It can perform the individual power control or partial on/off control of a LED lamp by control center and can detect the error of the LEDs by current sensing. Also, the ability to control the brightness and period of on/off by detecting the car's existence. This light control circuit consists of road line lamp unit device. It can give a lot of solutions when the server, which controls the whole system, is operated through CDMA(Code-Division Multiple Access) network.