• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.145-148
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• 2006

The protocrystalline silicon (pc-Si:H) multilayer solar cell is very promising owing to its fast stabilization with low degradation against light irradiation. However, the pc-Si:H multi layers have not extensively been investigated in detail on its material characteristics yet. We present the material characteristics of pc-Si:H multilayer using a transmission electron microscopy(TEM), and Raman spectroscopy. In addition, we present the superior light-soaking behavior of the pc-Si:H mutt i layer solar cell. A TEM micrograph shows that a pc-Si:H multilayer has a repeatedly layered structure and crystalline-like objects in a-Si:H matrix. A Raman spectra introduces improved short-range-order and medium-range-order in pc-Si:H multilayer. As a result the excellent metastability of the pc-Si:H multilayer solar cell is primarily due to the repeatedly layered structure that improves a structural order in absorber layer.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.73-78
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• 2017

This study provide activity for beauty food of water and 80 % ethanol extracts from Pinus koraiensis leaves. Total phenolic content of extracts from Pinus koraiensis leaves were each 12.22 mg/g (Drying under hot air) and 17.93 mg/g (Drying under shade), 14.36 mg/g (Lyophilization) in water extracts (WE) and 11.9 mg/g and 20.63 mg/g, 17.96 mg/g in 80 % ethanol extracts (EE). The 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity of extracts from Pinus koraiensis leaves was 96.20 % in EE from drying under shade at extracts concentration. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical decolorization activity of extracts from drying under shade was 99.85 % in WE and 99.80 % in EE at extracts concentration. The antioxidant protection factor (PF) extracts from drying under shade type was 9.63 PF in WE and 10.48 PF in EE at extracts concentration. The thiobarbituric acid reactive substance from Pinus koraiensis leaf was 89.39 % in EE from drying under shade at extracts concentration. The elastase inhibition activity of EE for anti-wrinkle effect showed an excellent wrinkle improvement effect, showing 71.46 % in EE from lyophilization. Collagenase inhibition activity of EE from drying under shade was 97.48 % in extracts. Tyrosinase inhibition activity which was related to anti-melanogensis was observed. The tyrosinase inhibitory effect of extracts from lyophilization was confirmed to be 60.4 % in EE more than another drying methods at extracts concentration. Through out all results, it can be expected Pinus koraiensis leaves extracts to use as a functional material for anti-oxidant and functional beauty food.

• Korean Journal of Radiology
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• v.24 no.3
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• pp.173-176
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• 2023

• Korean Journal of Radiology
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• v.24 no.4
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• pp.371-371
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• 2023

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.609-617
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• 2013

The objective of this study was to evaluate the oxidation method to remove endocrine disrupting chemicals in reverse osmosis(RO) retentate for the reuse of wastewater effluent. Oxidation of organic pollutants was induced by the persulfate catalyzed by Fe(II). Affecting factors such as initial pH and ionic strength on the Fe(II) catalyzed persulfate oxidation were evaluated. $17{\alpha}$-ethynylestradiol (EE2) degradation efficiency decreased as pH and ionic strength increased. However, the efficiency increased as chloride ion concentration increased due to the influence of radical transfer.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.450-453
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• 2002

In emergency telemedicine system based on wireless communication system with limited transmission capacity, it is necessary to transmit the biological data (ECG, BP, Respiration, $SpO_2$) of the patient continuously and reliably in real time. For this service, it is necessary to data compression and error control. In this study, we designed an protocol for error control in application layer and implemented it on the biological data transmission program for an emergency telemedicine system based on wireless data communication system.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.275-278
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• 1987

In this paper, a programming system for SCARA-type robots is designed, consisting of robot language, computational facilities and programming tools for handling interconnection environments. In designing the robot language, CLRC(C Library for Robot Control) is introduced, using the general-purpose language 'C' as base programming language. Also the motion primitives for Continuous Path control as well as Point-To-Point motion arc included. By means of frame and homogeneous transformations the system is capable of applying the SCARA-type robot efficiently and easily for any given task.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.325-328
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• 2004

본 논문에서는 PAST(Projection Approximation Subspace Tracking)에 기반 한 새로운 부공간(subspace) 추적 알고리즘을 제안하고자 한다. 빠른 시분할 대상의 목표물의 방위각을 추정하는 것이 필요하다. 그러나 PAST 기법은 고속의 시분할 환경에서는 잘 동작하지 않는다 따라서 가변망각 인자를 도입하여 빠르게 변화하는 부공간의 비정재 (Nonstationary) 상태에 잘 적응시켜 PAST 성능 향상을 보고자 한다.

• Journal of the Korean earth science society
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• v.39 no.2
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• pp.119-130
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• 2018

Aerosol Optical Properties (AOPs) are retrieved using the geostationary satellite instruments such as Geostationary Ocean Color Imager (GOCI), Meteorological Imager (MI), and Advanced Himawari Imager (AHI) through Yonsei AErosol Retrieval algorithm (YAER). In this study, the retrieved aerosol optical depths (AOD)s from each instrument were intercompared and validated with the ground-based sunphotometer AErosol Robotic NETwork (AERONET) data. As a result, the four AOD products derived from different instruments showed consistent results over land and ocean. However, AODs from MI and GOCI tend to be overestimated due to cloud contamination. According to the comparison results with AERONET, the percentage within expected errors (EE) are 36.3, 48.4, 56.6, and 68.2% for MI, GOCI, AHI-minimum reflectivity method (MRM), and AHI-estimated surface reflectance from shortwave Infrared (ESR) product, respectively. Since MI AOD is retrieved from a single visible channel, and adopts only one aerosol type by season, EE is relatively lower than other products. On the other hand, the AHI ESR is more accurate than the minimum reflectance method as used by GOCI, MI, and AHI MRM method in May and June when the vegetation is relatively abundant. These results are explained by the RMSE and the EE for each AERONET site. The ESR method result show to be better than the other satellite product in terms of EE for 15 out of 22 sites used for validation, and they are better than the other product for 13 sites in terms of RMSE. In addition, the error in observation time in each product is found by using characteristics of geostationary satellites. The absolute median biases at 00 to 06 Universal Time Coordinated (UTC) are 0.05, 0.09, 0.18, 0.18, 0.14, 0.09, and 0.10. The absolute median bias by observation time has appeared in MI and the only 00 UTC appeared in GOCI.

• Archives of Pharmacal Research
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• v.23 no.3
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• pp.226-229
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• 2000

To obtain the standard compounds of metoprolol for a pharmacokinetic study, a convenient synthetic procedure to prepare enantiomers of metoprolol (3a) and its major metaboites, 2-4-(2-hydroxy-3-isopropylamino)propoxyphenylathanol (3b) and 4-(2-hydroxy-3- isopropylamino) pro-poxyphenylacetic acid (4), was developed from their respective starting materials, 4-(2-methoxyethyl)phenol (1a), 4-(2-hydroxyethyl)phenol (1b) and methyl 4-hydroxyphenylacetate (1c). These phenolic compounds (1a, b, c) were converted in situ to their corresponding phenoxides with sodium hydroxide treatment followed by (R)- or (S)-epichlorohydrin treatment. The resulting epoxides 2 were transformed to 3 through reaction with isopropylamine. Ester 3c was hydrolyzed to the metabolite 4. Measured using the HPLC method on chiral column without any derivatization, the optical purity of enantiomers of metoprolol and o-demethylated metabolite 3b ranged between 96-99 ％ ee and that of enantiomers of carboxylic acid metabolite 4 ranged 91％ ee.