• Journal of Broadcast Engineering
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• v.15 no.1
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• pp.76-88
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• 2010

Recently, LED background image devices are used for the production of broadcasting programs. But the effective advantages of LED background image devices are not realized for good HD video quality because the correlations between lighting sources and LED background image devices are not analyzed yet. In this paper, we analyze the color change and light intensity that lighting sources and the light intensity ratio of LED background images influence on a subject, making use of equipments used in real broadcasting, and examine the correlations between HD video quality and the light intensity ratio of LED background images. As a result in this experiment, the video is most expressed having an 20[IRE] effect on a subject when the light intensity of LED background image is 6%. When the LED background image is light, the light and darkness of video is distorted and when the LED background image is dark, the colors of image are distorted.

• The Journal of Korean Academy of Prosthodontics
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• v.16 no.1
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• pp.38-44
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• 1978

Color is an important factor in dental esthetics. Application of natural tooth color will not fail to produce pleasing results. But a standardized method of shade matching has not been adopted. If we are to overcome the color matching problem in dentistry, an understanding of the nature of color and light is essential. The purpose of this study was to compare the effects of different light sources and different background colors on the ability of observers to correctly match shades of artifical teeth. And observation was made to determine if the time spent in making a shade match was a factor in the correctness of the response. A test method was devised and 50 individuals made observations which were recorded and analyzed. $X^2$-test gave results indicating that the time factor had no effect on the response made. An analysis of variance showed the following effects significant at the five percent level; (1) light source (2) background color (3) subject. The following conclusions can be drawn from this study; (1) The time spent in making shade selection is not a factor in the correctness of the selections. (2) The light source used is an important factor in matching tooth shade; and there is no significant difference between the light sources in shade matching. (3) Under the conditions of this study, the greatest accuracy in shade matching was obtained on the brown background.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.1946-1963
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• 2014

Most background subtraction methods focus on dynamic and complex scenes without considering robustness against noise. This paper proposes a background subtraction algorithm based on dictionary learning and sparse coding for handling low light conditions. The proposed method formulates background modeling as the linear and sparse combination of atoms in the dictionary. The background subtraction is considered as the difference between sparse representations of the current frame and the background model. Assuming that the projection of the noise over the dictionary is irregular and random guarantees the adaptability of the approach in large noisy scenes. Experimental results divided in simulated large noise and realistic low light conditions show the promising robustness of the proposed approach compared with other competing methods.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.321-326
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• 2017

We analyzed spectral data of the astrophysical diffuse emission obtained with the low-resolution spectroscopy mode on the AKARI InfraRed Camera (IRC) in the $1.8-5.3{\mu}m$ wavelength region. Advanced reduction methods specialized for slit spectroscopy of diffuse sky spectra have been developed, and a catalog of 278 spectra of the diffuse sky covering a wide range of Galactic and ecliptic latitudes was constructed. Using this catalog, two other major foreground components, the zodiacal light (ZL) and the diffuse Galactic light (DGL), were separated and subtracted by taking correlations with ZL brightness estimated by the DIRBE ZL model and with the $100{\mu}m$ dust thermal emission, respectively. The isotropic emission was interpreted as the extragalactic background light (EBL), which shows significant excess over the integrated light of galaxies at <$4{\mu}m$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.365-372
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• 2007

The function of navigational aids are to be coincided with the development of navigational equipment and increase of traffics on the sea fairway. Supplementary function or side effect of wharf-edge illumination would be effective to indicate fairway indirectly and collision avoidance between ships and bridge against background light in port area at night also a serious-view light on the bridge posts would be effective to ensure the drifting ships by wind and current force adjacent bridge area.

• Korean Institute of Interior Design Journal
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• no.6
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• pp.6-14
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• 1995

The purpose of this study is to establish the direction for creating the beautiful and lively space of the reli-gious architecture as a consquence of trying to under-stand the forms of control of the light and the symbolic meaning of the production in the interior space of the re-ligious architecture. The scope of this study has been limited to the natural light and to the establishment of theoretical background by analyzing the essence and method of space formation by the light in a side view of development and psychology and establishing the concept related to the architectur-al space formation of the light as well as researching and analyzing the meaning and the method of production of the light. And at the same time the conclusion has been induced as a guide of verifying theoretical background by analyz-ing the practical use related to the control and the pro-duction of the light through the spot research and the referential materials in a way of case research into 5 do-mestic religious architectures as the subject of research.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1505-1506
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• 2013

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.71-77
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• 2000

The color of an esthetic restorative material is controlled primarily by thickness of the material and background color. Although the effects of the two factors on the color coordinates of esthetic dental materials have been reported, the mechanism has not been clarified well enough to explain the effects quantitatively. The purpose of this study was to evaluate the effect of thickness and background color on the color of tooth colored restorative materials quantitatively. One hundred sixty samples were fabricated from two commercial light-cured composite resins and two commercial compomers. The color characteristics and changes in the color coordinates were measured by a tristimulus colorimeter (Model TC-6FX, Tokyo Denshoku Co. Japan) using the CIELAB system. The results were as follows: 1. As thickness increased from 1.0 to 4.0mm, values of $L^*$ $a^*$ $b^*$ changed irregulary for white and dentin color background, but showed no obvious difference in color for black background. 2. The colors of composite resins and compomers were significantly influenced by background color. 3. The color difference was recognized even the same shade name in four representative kinds of composite resins and compomers. 4. As thickness changed, values of color difference for same products and same background color showed constancy, but showed difference for different background color.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.4
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• pp.60-66
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• 2005

In this paper, we propose the basic measurement method of a 3D digitizer using a CCD camera in detail. In the localization measurement with a CCD camera, the effect of the background light and the sensitivity consideration are always problems in realizing a high precision. In this research, a new measurement principle is proposed in which the pulse compression technique known in radar is used to eliminate the effect of background light even under a low intensity light source, and the coordinate values on the CCD camera image plane are determined accurately. From the quantitative evaluation of the S/N ratio improvement and the fundamental experiment, it is verified that a substantial improvement in the S/N ratio is realized for both the background noise and the pixel noise and that a resolution of less than the pixel is sufficiently possible.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.22-30
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• 2015

Currently, in South Korea, 'Light Pollution Prevention Act by Artificial Lighting' has been enforced. For advertising lighting, it is limited based on only the light-emitting luminance. Luminance is a concept related to the glare. Not only the luminance of the light source, but also glare is affected depending on some situations like blinking, luminance contrast, background illuminance. This study conducted glare subjective evaluation with brightness, color, and blinking by looking at the LED lighting box. The results showed that the glare indexes were higher about 2 times in a decrease of background illuminance from 100lx to 0lx. The glare index of R, G, B light was higher than that of white light. The average glare index of the blue light was higher about 8 times compared to 2,700K. And the blink rate had little effect on the glare, but it affected the irritation. Therefore, the glare effect of light color and blinking needs to be considered for the standard of luminous environment.