• Applied Biological Chemistry
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• v.37 no.4
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• pp.295-302
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• 1994

For the development of biological wastewater treatment process using photosynthetic bacteria (PSB), photosynthetic sludge process consisted of anaerobic digestion and PSB reactor were designed for the treatment of swine wastewater and the optimal operating conditions in flask-scale were examined. Photosynthetic bacteria from soil, pond, rice field, ditch etc. were isolated in synthetic medium containing high amount of organic acids and finally isolated one strain KK14 which showed the most degradating ability of organic acids was selected for the treatment of swine wastewater. It was identified as Rhodopseudomonas palustris. In the anaerobic digestion stage, the maximum organic acid productivity was obtained at pH 5.0, $37^{\circ}C$, HRT 2 day and under anaerobic standing condition. The optimal operating conditions of PSB reactor for the treatment of swine wastewater were pH 7.0, $30^{\circ}C$ under 4,000 lux illumination, and optimal initial COD loading (kg COD/kg D. C. W of PSB) was 2 (20% v/v seeding) in the main purification stage. Maximum removal rate of COD reached 92% under the above optimal conditions for 5 days.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.488-494
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• 1993

A photosynthetic bacterium strain P17 having high growth rate and assimilating ability of organic acids was isolated from several soil samples, which was identified as Rhodospirillum rubrum. Cultural conditions of the strain P17 were examined for the production of starter culture used in the treatment of organic waste water. The addition of organic acids mixture as carbon source containing 0.2% Na-acetate, 0.1% Na-propionate and 0.2% Na-lactate and 0.1% of yeast extract as growth factor stimulated the cell growth. The maximal cell production was obtained at $30^{\circ}C$, pH 7.0, 2,500 lux of illumination and $50{\sim}100\;rpm$ of agitation. Under the optimal conditions of batch and fed-batch culture systems in a Jar fermentor, 5.17 g/l and 7.93 g/l of cells were obtained after S days of cultivation, respectively. In continuous culture system, the cell productivity was 0.206 g/l/h at a dilution rate of 0.21 $h^{-1}$. When R. rubrum P17 was cultivated in a soybean curd waste water, initial COD level(3,240 mg/l) of the waste water was reduced to 250 mg/l after 4 days of cultivation.

• Science of Emotion and Sensibility
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• v.16 no.2
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• pp.195-206
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• 2013

The main causes of traffic accidents while driving a car is of the driver's visual distraction. In this study, the color sensitivity of the information projected on the windshield were evaluated for HUD (Head Up Display) system which helps the driver's eyes on the road while driving. The driving Information were projected $9^{\circ}$ downward from front sight $0^{\circ}$ under lab's fluorescent lights, LED floorlights and the TV had having 25 [lux] illumination when driving at night environment and 100,000 [lux] of daylight environment. Munsell color hue of the basic five colors (R, Y, G, B, P) and the color of traffic lights YR, W were the color of the seven characters, each character were outlined by White, Gray except for W. Total of 19 experimental stimuli was shown in the environment of day and night driving for asking visibility information of color, fatigue, preferences, and evaluate the degree of interference. The results came out that the bright Y and G color is visibility significantly for daylight. Second, with the outline of the text, the color of the outline works as a background for luminance contrast effects and affects visibility. Third, without the outline, the glass in front of the vehicle acts as the background and the luminance contrast of characters achieve greater brightness and visibility. The luminance contrast between the stimuli and background should be considered for increasing color visibility for driving information which is an important factor for HUD commercialization.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.286-296
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• 2010

The study of the development of DJ robots is to meet the demands of the music services which are changing very rapidly in the digital and network era. Existing studies, as a whole, develop music services on the premise of personalized environment and equipment, but the DJ robot is on the premise of the open space shared by the public. DJ robot gives priority to traditional space and music. Recently as the hospitality and demand for cultural contents of South Korea expand to worldwide, industrial use of the contents based on traditional or our unique characteristics is getting more and more. Meanwhile, the DJ robot is composed of a combination of two modules. One is to detect changes in the external environment and the other is to set the properties of the music by psychology, emotional engineering, etc. DJ robot detect the footprint of the temperature, humidity, illumination, wind, noise and other environmental factors measured, and will ensure the objectivity of the music source by repeated experiments and verification with human sensibility ergonomics based on Hevner Adjective Circle. DJ robot will change the soundscape of the traditional space being more beautiful and make the revival and prosperity of traditional music with the use of traditional music through BGM.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.2
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• pp.111-118
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• 2005

The optotypes widely used as a necessity in the course of optometry are the world authorized versions which contain items such as the Landolt's rings, Snellen's chart and also Arabian numbers, Korean letters, Pictures and so on. In Korea, the Hahn-chun-suk test chart has been In use generally alolng with Chung-san test chart and Jin-yong-han test chart also in use on the wall. But these sort of test charts hung on the wall have some problems such as the difference in test results owing to the rate of illumination and so a more accurate method is required. To solve the problem of inaccuracy in optometry, the projected type of charts with digital instrument such as the beam projector has been developed lately. This chart projector with consistent high resolution and the ability to provide various charts can help eye examiner perform effective examination and thus is looked positively upon as the automated total optometry system. So in this study our purpose is to examine the accuracy of the projected chart. It was done by comparing it with the frequently used test chart. The results of experiment are as follow. When the projected chart was used, cases that subject read charts one step higher were 10%, two step higher 2% than perfectly corrected vision. When Han-chun-suk test chart was used, cases that subject read charts one step higher were 12%, and two step higher were 4%.

• Journal of Astronomy and Space Sciences
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• v.33 no.2
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• pp.127-135
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• 2016

Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, and its drift trajectory has been monitored with the optical wide-field patrol network (OWL-Net). However, a quantitative analysis of KOREASAT 1 in regard to the attitude evolution has never been performed. Here, two optical tracking systems were used to acquire raw measurements to analyze the rotation period of two inactive satellites. During the optical campaign in 2013, KOREASAT 1 was observed by a 0.6 m class optical telescope operated by the Korea Astronomy and Space Science Institute (KASI). The rotation period of KOREASAT 1 was analyzed with the light curves from the photometry results. The rotation periods of the low Earth orbit (LEO) satellite ASTRO-H after break-up were detected by OWL-Net on April 7, 2016. We analyzed the magnitude variation of each satellite by differential photometry and made comparisons with the star catalog. The illumination effect caused by the phase angle between the Sun and the target satellite was corrected with the system tool kit (STK) and two line element (TLE) technique. Finally, we determined the rotation period of two inactive satellites on LEO and geostationary Earth orbit (GEO) with light curves from the photometry. The main rotation periods were determined to be 5.2 sec for ASTRO-H and 74 sec for KOREASAT 1.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.155-167
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• 2016

Technology valuation is necessary for determining the feasibility of technology commercialization. However, existing methods focus only on technology evaluation, with limitation in sufficiently reflecting buyer viewpoint. In addition, it causes a gap between estimated value and market value. Therefore, this research suggests a new technology valuation method which focuses on the perspectives of buyers. Technology factors, buyer factors and market factors are first determined and their relationships are analyzed. Second, based on the relationships, profit projections are calculated using the discount cash flow method. Finally, profit projections for each year are discounted. The proposed method was applied using the ubiquitous home network system and audio service and illumination control method and results compared with the value of a technology valuation guide distributed by the Ministry of Trade, Industry and Energy. The technology valuation approach used in this research is quantitative and systematic and can be used as a decision making support tool in technology transfer, reflecting various perspectives of stakeholders.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.4
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• pp.202-209
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• 2002

The stochiometric mix of evaporating materials for the $CuInSe_2$single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CuInSe_2$compound crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $620^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CuInSe_2$single crystal thin films measured from Hall effect by van der Pauw method. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $CuInSe_2$single crystal thin film, we have found that the values of spin orbit splitting $\Delta$So and the crystal field splitting $\Delta$Cr. From the photoluminescence measurement on $CuInSe_2$single crystal thin film, we observed free exciton ($E_x$) existing only high quality crystal and neutral bound exciton ($A^{\circ}$, X) having very strong peak intensity. Then, the full-width-at-half-maximum (FWHM) and binding energy of neutral donor bound exciton were 7 meV and 5.9 meV, respectivity. By haynes rule, an activation energy of impurity was 59 meV.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.211-220
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• 1998

The stochiometric composition of $AgGaS_2$polycrystal source materials for the single crystal thin films were prepared from horizontal furnace. From the extrapolation method of X-ray diffraction patterns, it was found that the polycrystal $AgGaS_2$has tetragonal structure of which lattice constant $a_0\;and \;c_0$ were 5.756 $\AA$ and 10.305 $\AA$, respectively. $AgGaS_2$single crystal thin film was deposited on throughly etched GaAs(100) substrate from mixed crystal $AgGaS_2$by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $590^{\circ}C$ and $440^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about 0.5 $mu \textrm{m}$/h. The crystallinity of the grown single crystal thin films was investigated by the DCRC (double crystal X-ray diffraction rocking curve). The optical energy gaps were found to be 2.61 eV for $AgGaS_2$single crystal thin films at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation, then the constants in the Varshni equation are given by${\Alpha};=;8.695{\times}10^{-4};eV/K,and;{\beta};=;332;K$. from the photocurrent spectra by illumination of polarized light of the $AgGaS_2$single crystal thin film, we have found that crystal field splitting $\Delta$Cr was 0.28 eV at 20 K. From the PL spectra at 20 K, the peaks corresponding to free and bound excitons and a broad emission band due to D-A pairs are identified. The binding energy of the free excitons are determined to be 0.2676 eV and 0.2430 eV and the dissociation energy of the bound excitons to be 0.4695 eV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.175-178
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• 2004

The stochiometric mixture of evaporating materials for the $ZnIn_2S_4$ single crystal thin film was prepared from horizontal furnace. To obtain the $ZnIn_2S_4$ single crystal thin film, $ZnIn_2S_4$ mixed crystal was deposited on throughly etched semi-insulating GaAs(100) in the Hot Wall Epitaxy(HWE) system. The source and substrate temperature were $610^{\circ}C$ and $450^{\circ}C$, respectively and the growth rate of the $ZnIn_2S_4$ sing1e crystal thin film was about $0.5\;{\mu}m/hr$. The crystalline structure of $ZnIn_2S_4$ single crystal thin film was investigated by photoluminescence and double crystal X-ray diffraction(DCXD) measurement. The carrier density and mobility of $ZnIn_2S_4$ single crystal thin film measured from Hall effect by van der Pauw method are $8.51{\times}10^{17}\;cm^{-3}$, $291\;cm^2/V{\cdot}s$ at $293_{\circ}\;K$, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the $ZnIn_2S_4$ single crystal thin film, we have found that the values of spin orbit splitting ${\Delta}S_O$ and the crystal field splitting ${\Delta}Cr$ were 0.0148 eV and 0.1678 eV at $10_{\circ}\; K$, respectively. From the photoluminescence measurement of $ZnIn_2S_4$ single crystal thin film, we observed free excition $(E_X)$ typically observed only in high quality crystal and neutral donor bound exciton $(D^{o},X)$ having very strong peak intensity The full width at half maximum and binding energy of neutral donor bound excition were 9 meV and 26 meV, respectively, The activation energy of impurity measured by Haynes rule was 130 meV.