• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.51.4-52
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• 2015

From 2010 to 2014, CQUEAN (Camera for QUasars in EArly uNiverse) has been operated for the observation at the 82 inch Otto Struve Telescope of the McDonald Observatory, US. This camera is optimized at wavelength range of 0.7 - 1.1 um with seven (g', r', I', z', Y, Iz and Is) broad-band filters for the survey of high redshift (z > 5) quasars in the early universe. We are upgrading this system to identify more details of SED (Spectral Energy Distribution) of quasar candidates and other astronomical sources. The SQUEAN is comprised of a focal reducer, a CCD camera, a new filter wheel, new auto guiding system and new control software. The new filter wheel consists of interchangeable cartridges for various wavelength and size of filters. 50 nm medium bandwidth filters from 600 - 1050 nm, seven SDSS (Sloan Digital Sky Survey) filters and Johnson-Cousin BVRI filters are installed for now. We also have a plan to use narrow band interference filters to classify high redshift quasars or to obtain SEDs of interesting astronomical sources in details more efficiently. We also developed KAP82 (Kyung Hee University Auto guiding Package for 82 inch telescope) for auto guiding software. CQUEAN and SQUEAN have been developed by CEOU (Center for the Exploration of the Origin of the Universe).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.5
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• pp.408-417
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• 1996

In this paper, we quantiatively analyze the broadband CDMA systems with high chip rate, which virually eliminates the multipath fading effects by distinguishing each reflected paths in the process of despreading. We model the broadband multipath propagation channel with random time-variant impulse response as a linear filter of tapped delay line to evaluate the performance of broadband CDMA systems in multipath fading environment. This statistical model, based on extensive experimental data, was established to characterize the urban radio propagation medium in various environments. We perform computer simulation of the transmission and reception of broadband CDMA systems by applying it to abve channel model. From the simulation results, we confirm that the broadband CDMA systems inherenly reduce the effects of multipath fading phenomena which causes to degrade the performance of mobile communication systems, based on the results of eye-diagram and BER curve.

• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.99-117
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• 1991

The purpose of this study is to evaluate the effects of dentin bonding agents on the fibroblasts cultivated from human pulp tissue. The fibroblasts were cultured in DMEM/10%FBS medium. Whatman filter paper discs (6mm diameter) soaked with $2{\mu}l$ of dentin bonding agents were placed on a millipore filter (pore size $0.22{\mu}m$) contained in a 50mm Petri dish, and then, exposed for 10 minutes, 30 minutes, 1 hour, 6 hours, 12 hours, 24 hours, 4 days and 7 days in $37.^{\circ}C$, 5% $CO_2$ incubator. The results of the experiments were analyzed by counting the cells and measuring the protein contents at 1 day, 4 days and 7 days. The results of this study were as follows: l. CLEARFIL NEW BOND, LITE-FIL BOND, GLUMA 3 Primer and GLUMA 4 Sealer showed cytotoxicity compared to the control group in the cell counts and the protein contents. 2. GLUMA 4 Sealer showed the least cytotoxicity among the three dentin bonding agents. 3. The results of the cell count were simialr to the results of protein content measurement. 4. LITE-FIL BOND exhibited marked cytotoxicity during 1 day, but, the cytotoxicity was slightly reduced after 4 and 7 days. 5. In GLUMA 3 Primer group, it was not possible to count the cell numbers and measure the protein contents, but the degeneration of cells was observed under the inverted phase-contrast microscope.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.482-488
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• 2015

Biological treatment is promising alternative to conventional air pollution control method. Bioreactors for air pollution control have found most of their success in the treatment of dilute and high flow waste air streams containing volatile organic compounds and odor. The studies of mass transfer in biotrickling filters for air pollution control were of importance in order to control and optimize the purification process. The objectives of this study were to develop the experimental methodologies to evaluate the mass transfer coefficients of gas/liquid(trickling liquid), gas/solid(biomass) and liquid/solid in three phase biotrickling filtration. Also, this study characterized the influence factors on mass transfer such as dynamic holdup volume, gas/liquid flow rate ratio, biomass weight in reactor and recirculation rate of trickling medium for each phase of biotrickling filter.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.307-312
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• 2015

ARPA(Automatic Radar Plotting Aid) is a device to calculate CPA(closest point of approach)/TCPA(time of CPA), true course and speed of targets by vector operation of relative courses and speeds. The purpose of this study is to develop target acquisition and tracking technology for ARPA Radar implementation. After examining the previous studies, applicable algorithms and technologies were developed to be combined and basic ARPA functions were developed as a result. As for main research contents, the sequential image processing technology such as combination of grayscale conversion, gaussian smoothing, binary image conversion and labeling was deviced to achieve a proper target acquisition, and the NNS(Nearest Neighbor Search) algorithm was appllied to identify which target came from the previous image and finally Kalman Filter was used to calculate true course and speed of targets as an analysis of target behavior. Also all technologies stated above were implemented as a SW program and installed onboard, and verified the basic ARPA functions to be operable in practical use through onboard test.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.28 no.3
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• pp.14-29
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• 2015

Objectives : The extract of Sagunja-tang has been traditionally used for restorative treatment of constitutional weakness, vascular and immune disorder, and nervous disease in Oriental country. This study investigated the regulatory effects of Sagunja-tang on the expression, production, and activity of immune mediators.Methods : In this study, the extract of Sagunja-tang was prepared by extracting with distilled water at 100$^{\circ}C$ for 2.5h. The extract was freeze-dried following filtration through 0.45${{\mu}m}$ filter. The extract was dissolved in Hank's balanced salt solution (HBSS) and filtered again through 0.45${{\mu}m}$ filter before use. The level of nitrite, an oxidative product of nitric oxide(NO) was measured in the culture medium by the Griess reaction. The levels of prostaglandin E₂(PGE₂), Th1 cytokines (IFN-${\gamma}$, IL-2) and Th2 cytokines(IL-4, IL-5, IL-13) were measured by enzyme-linked immunosorbent assay and the protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression were determined by Western blot analysis. Also examined the effects of the extract on T-cell proliferation and cytotoxic activity of natural killer cells.Results : In this investigation, Production levels of Th2 cytokines (IL-4, IL-5, IL-13) was inhibited in a dose dependent manner by treatment with the extract. I also found that the extract increased T-cell proliferation and cytotoxic activity of natural killer cells in a dose-dependent manner.Conculsions : These results suggest that the water extract of Sagunja-tang may be useful for a therapeutic drug against a sickly constitution and immune diseases, probably by regulating the production of immune mediators.

• Applied Biological Chemistry
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• v.37 no.4
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• pp.226-233
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• 1994

Three hundred and one cellulolytic bacterial were isolated from the 148 screening sources such as decomposed wood, soil, compost and leaf mold. Among them, strain KL-6 was found to have the highest of cellulase activity, and identified as species belonged to the genus Cellulomonas. Strain KL-6 was decompose up to 90% of the filter paper (whatman No. 1) substrate within 50 hours, and showed the colony halo formation (11 cm). The activities of CMCase (67 unit/ml), FPase (70 unit/ml) and ${\beta}-glucosidase$ (0.68 unit/ml) were obtained when this strain was cultured for 50 hrs at $30^{\circ}C$. Glucose was not found in detectable amounts at the FP medium. The optimum composition of nutrient medium for the cell growth by strain KL-6 was sucrose 0.5%, yeast extract 0.1%, $(NH_4)_2HPO_4\;0.1%$, $K_2HPO_4\;0.1%$, $MgSO_4{\cdot}7H_2O\;0.01%$, $CaCl_2\; 0.01%$, NaCl 0.6%, $CaCO_3\;0.1%$ and the optimum pH and temperature were 7.0 and $30^{\circ}C$, respectively.

• Journal of Plant Biotechnology
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• v.4 no.1
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• pp.29-32
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• 2002

The ability to form embryiod from callus in satsuma mandarin is low and unstable. In this study, the conditions of embryogenic calli induced from nucellar tissue for promotion of plant regeneration in satsuma mandarin were investigated. The calli of I, II and III line were divided into two sizes of 0.5 mm and 1.0 mm in diameter and two weight gradients of percoll at 40% and 50% though the filter mesh. The frequency of embryo formation from $\phi$ 1.0mm-40% was slightly higher than callus that from others. Adventitious embryoids developed to a globular stage were transferred to regeneration medium. In 'Miyagawa Wase', the embryos from I and II line developed into a heart stage from most of $\phi$ 0.5 mm- 40% and $\phi$1.0 mm-40% calli, but it failed in 'Sugiyama Unshu'. In the cultivar of 'Miyagawa Wase', 63% of adventitious embryos transferred to the regeneration medium developed into the heart stage from the most $\phi$ 1.0 mm-40% calli of I line, but of 'Sugiyama Unshu' failed in some calli condition. The embryoids from two callus lines developed further to shoots and plantlets, while the embriods from III line abnormal failed to regenerate in the cultivar. From these results, it is suggested that the plant regeneration from embryogenic callus in satsuma mandarin could be affected by callus conditions.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.125.2-125.2
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• 2011

We are developing medium resolution cross-dispersed silicon grisms in the near IR region ($1.45{\sim}5.2{\mu}m$). The grisms will be installed in MIMIR, a multifunction instrument at the Lowel Observatory, USA. The two devices are designed to cover H and K band and L and M band simultaneously. Our goal is to make grism with R=3000 at 1.2 arcsec slit. The Silicon has high refractive index (n=3.4 at $1.5{\mu}m$) which enhances the resolving power by up to 5 times when compared to conventional material such as BK-7 (n=1.5 at 1.5 ${\mu}m$). The bonded grisms will be installed in a filter wheel for the uses switch from spectroscopic mode to imaging mode easily. Our device is compact and light weighted while it provides a decent resolving power. We produce monolithic grisms using e-beam lithography at the NASA JPL and chemically etching the grooves on the silicon prisms. Moreover, the main-disperser and cross-disperser will be contacted together by direct Si-Si bonding technique and eventually turn into one piece. The bonded pair offers more stability in terms of the layout of the spectrum and removes the Fresnel loss at the intersection of two grisms. We report on the proper wafer bonding steps through this research, and inspected the bonding quality thermally, optically and mechanically.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.3
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• pp.269-274
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• 2011

The purpose of hull stress monitoring system(HSMS) is to lead hull structure to be safer at lower cost. We proposed a hull stress monitoring system for leisure boats using fiber-optic bragg grating(FBG) strain sensor. Fiber optic sensors are well suited for structure monitoring system, due to their ability to withstand harsh environments, immunity to electromagnetic interference, and reduce cabling installation cost when employing wavelength multiplexing. This paper presents an overview of current research and design of hull stress monitoring system for leisure boats.