• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.442-449
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• 2004

Improving the light utilization efficiency of photosynthetic cells in photobioreactors (PBRs) is a major topic in algal biotechnology. Accordingly, in the current study we investigated the effect and suitability of photosynthetic pigment reduction for improving light utilization efficiency. The light-harvesting complex II (LH-II) genes of Rhodobacter sphaeroides were removed to construct a mutant strain with less pigment content. The mutant strain exhibited a slower growth rate than the wild-type under a low light intensity, while the mutant grew faster under a high light intensity. In addition, the specific absorption coefficient was lower in the mutant due to its reduced pigment content, thus it seemed that light penetrated deeper into its culture broth. However, the distance (light penetration depth) from the surface of the PBR to the compensation point did not increase, due to an increase in the compensation irradiance of the mutant strain. Experimental data showed that a reduced photosynthetic pigment content, which lessened the photoinhibition under high-intensity light, helped the volumetric productivity of photosynthetic microorganisms.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.75-75
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• 2003

All published and newly observed times of minimum light of the massive, early-type eclipsing binary star AH Cep were analyzed. After subtracting the light time effect due to the well-known third body from the residuals of the observed times of minimum light, it was found that the second-order Ο-C residuals varied in a cyclical way. It was assumed that the secondary oscillations were produced by a light time effect due to a fourth body so all the times of minimum light were reanalyzed with a differential least-squares scheme in order to obtain the light time orbits due to both the third and fourth bodies. The periods, eccentricities, semi-amplitudes of the light time orbits for the third and fourth-bodies were derived as : P$\_$3/=68.$\^$y/3 and P$\_$4/=9.$\^$y/3, e$_3$=0.53 and e$_4$=0.83, K$_3$=0.$\^$d/0585 and K$_4$=0.$\^$d/0045, respectively. The analysis of the radial velocities of AH Cep published so far, do not conflict with the hypothesis of the multiplicity of the system but their accuracies are not high enough to be useful to support the interpretation. Other properties of the distant bodies are discussed for assorted possible inclinations of their orbits.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.621-628
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• 2009

Because the Ultra-Precision Technology increase its competitiveness in the field of the design, precision of processing technology, confidence and fixation degree are major considerations. According to Pattern shapes using these processing technologies, Light Reflection has influence on the sense of sight about human being. Based on background of these studies, we draw a plan about a round workpiece using a 3D design program and analyze the effect on Light Reflection changing a pattern angle and a source of light through SPEOS program in this research. We make Pattern form as V-Shape, and compare the area distributed by Light Reflection by classifying angle into 4 and analyze changes according to a source of light. In order to measure and evaluate the data from simulation analysis we has manufactured Diamond Tool and has processed Pattern precision using a Ultra-Precision Machine. Based on the result of this study, we forecast that the field of design will achieve rapid growth due to Ultra-Precision Technology in the world market.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.169-170
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• 2023

In this study, light-heat generating materials were produced in two ways, and the performance of two light-generating insulation sheets was reviewed. As a result of the experiment, it was possible to confirm the improved heating performance of the light heating insulation sheet compared to the existing bubble sheet. The light heat insulation sheet (b) showed improved thermal properties compared to the existing bubble sheet, and it is believed that the temperature has increased due to the combined effect of initial hydration heat and heat generation after installation. In future studies additional experiments are needed to compensate for the insufficient insulation performance due to the single bubble sheet through the double bubble sheet and to adjust the amount of light-generating materials added as a consideration of the optimal heat-generating effect of the light-generating insulation sheet (b).

• 전기의세계
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• v.19 no.6
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• pp.8-12
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• 1970

A Device is described which intensity modulates a light beam at modulating frequency in the M/W region. A Method of designing a practical crystalline microwave-Freg. light modulator has been described. In addition, Electrooptic properties and operation as light modulator of NH$_{4}$H$_{2}$po$_{4}$ is described. A light path is provided through the crystal into a suitably oriented analyzer. The intensity of the light beam emerging from the latter varies at the same rate as the cavity frequency.

• Journal of the Korean Society of Costume
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• v.28
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• pp.205-212
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• 1996

This paper is to study the characteristics of fabrics dyed with astringent unripe persimmon juice. The cotton silk rayon and nylon fabrics were dyed with astringet unripe persimmon juice. The structures of natural fabrics dyed fabrics and dyed fabrics followed by washing were examined by scanning electron mi-croscopy. Surface reflexibility of VIS trans-mittance of UV VIS and NIR were analyzed. The study conclues as follows: 1. Colour of cotton fabrics dyed with persim-mon juice became darkended as a function of exposing time to sunlight. That colour was chaged after washing. 2. Blocking effect of ultraciolet light and visible ray was increased in all dyed fabrics. Especially dyed cotton fabric blocked UV light perfectly and the blocking effect was still remained after 9 washings. 3. Persimmon juice dyeing produced coating effect to fabrics besides dyeing effect accord-ing to the scanning electron micrographs. In a word the cotton fabric dyed with per-simmon juice has blocking effect of UV light stiffness. Therefore I think persimmon juice dyeing is a very useful textile finishing and ex-pect a wide application of the technique in fu-ture.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.63.3-64
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• 2017

KIC6118779 is an over-contact binary system having a short orbital period of about 0.36 days. The photometric data for this system are acquired by the observations of Kepler mission in the long cadence mode having a time resolution of about 30 minutes. It means that the Kepler light curves of the system may be strongly affected by phase smearing effect and the analysis of them without consideration of the phase smearing effect may result in wrong stellar properties. Additionally, this system also shows dynamical variation of light curve resulting from spot activity. For all those reasons, it is difficult to investigate KIC6118779, and the investigation should be carried out carefully. In this presentation, we introduce the phase smearing effect and carry out the light curve modeling with the 2015 version of the Wilson-Devinney binary code considering the phase smearing effect. Our results show that the system is a deep over contact binary system and has extremely low mass ratio of about 0.12. Moreover our spot modeling implies the cyclic migration of a big cool spot on the massive component.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.505-508
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• 2001

Currently there is much interested in removing latent charge that is caused to latent image effect and blurring of obtained image as well as reduction of x-ray conversion efficiency in digital radiography system. To remove latent charge a-Se film is irradiated by light with 3500 lux using halogen lamp and optical fiber. We measured dark current and photosensitivity to analyze removing effect of latent charge, then compared with and without light erasing method. The reduction of measured signal due to latent charge effect was 32.5 %, and the removal effect of latent charge by using light erase method was its 95.5 %.

• Journal of Astronomy and Space Sciences
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• v.9 no.1
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• pp.30-40
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• 1992

The reflection effect on three types of eclipsing binaries has been analyzed based on the Wilson and Devinney's model and Russell and Merrill's model. The reflection effect was displayed on the theoretical light curves for the various conditions using the Wilson and Devinney's light curve program. Two models were compared after the rectifing the theoretical light curves including the reflection effect with the Russell and Merrill's method. The result shows that two models have an agreement on the reflection effect just in cases of the small difference in temperature adn albedo between two stars in the system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.505-508
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• 2001

Currently there is much interested in removing latent charge that is caused to latent image effect and blurring of obtained image as well as reduction of x-ray conversion efficiency in digital radiography system. To remove latent charge a-Se film is irradiated by light with 3500 lux using halogen lamp and optical fiber. We measured dark current and photosensitivity to analyze removing effect of latent charge, then compared with and without light erasing method. The reduction of measured signal due to latent charge effect was 32.3%, and the removal effect of latent charge by using light erase method was its 95.5%.