• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.341-346
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• 1992

The antimutagenic effects of enzymatic browning reaction products (MEBRPs) of polyphenol compounds (catechol, homocatechol, hydroxyhydroquinone, pyrogallol) by enzyme extracted from mushroom (Agaricus bisporus) were demonstrated through spore rec-assay using B. subtilis $H17(rec^+)$ and $M45(rec^-)$, Ames test using S. typhimurium TA98 and TA100 and SOS chromotest using E. coli PQ37/plasmid pKM101. In spore rec-assay, the MEBRPs showed antimutagenic effects by decreasing of the inhibition zone induced by MNNG. In Ames test with S-9mix in both TA98 and TA100, all of MEBRPs showed strong antimutagenic effects of about 21 to 99% against mutation by $B({\alpha})P$ and Trp-P-1, as adding $300\;{\mu}l$ of the MEBRPs. In SOS chromotest, MEBRPs showed antimutagenic effects by inhibiting the SOS-inducing function induced by 4NQO and MMC, as increasing in concentration of the MEBRPs. But they did not showed mutagenicity in these bacterial assays.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.107-120
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• 1996

복합레진은 조작이 용이하고 강도가 우수하며 중합시간이 짧고 법랑질과 상아질에 접착이 가능하며 연마성이 뛰어나고 자연스러운 색상을 나타내므로 심미적 수복에 가장 일반적으로 선택되는 재료의 하나이다. 대부분의 복합레진 kit에는 shade guide가 포함되어 있어 이를 기준으로 중합된 후의 복합레진 색조를 예상하여 선택하게 된다. 그러나 이러한 shade guide들은 대개 복합레진이 아닌 plastic으로 제조된 것으로 중합된 복합레진의 실제 색조와는 차이가 생기게 되며 결국 shade guide 자체의 문제점으로 인해 이상적인 색조선택이 어려워진다. 이에 본 연구에서는 국내에 시판되고 있는 5종의 복합레진 제품을 선정하여 분광 광도계를 이용해서 shade guide와 중합된 복합레진 사이의 색조차이를 측정, 비교 연구하였다. 직경 16mm. 두께 1.6mm의 plastic mold에 5종의 광중합형 복합레진(Z100, Prisma TPH, Tetric, Silux Plus, Herculite XR)을 충전하고 응축기에 넣어 압축한 후 제조사의 지시에 따라 광중합기로 중합시킨 후 mold에서 시편을 제거하여 보관했다가 젖은 sandpaper 상에서 순차적으로 연마하였다. shade guide는 step부분을 갈아내어 복합레진 시편과 동일한 두께로 만든후 연마하였다. 분광광도계에 shade guide를 넣고 CIE illuminant D65 하에서 spectral reflectance를 측정하고 해당 색조의 복합레진 시편도 통일한 방법으로 측정하고 $L^*$, $a^*$, $b^*$값과 ${\Delta}E^*$값을 얻은후 분석하여 다음과 같은 결과를 얻었다. 1. Z100의 D3, A3, B2 shade와 Prisma TPH의 B2 shade를 제외한 모든 시편에서 shade guide와 복합레진간에 육안으로 인지할 수 있는 색차(${\Delta}E^*$ > 1.0)가 관찰되었다. 2. 평균적으로 Z100이 가장 적은 색차를 나타내었고 Prisma TPH, Tetric, Silux Plus, Herculite XR 순으로 색차가 증가하였다. 3. Prisma TPH의 A2 shade. Tetric의 W shade. Silux Plus의 YB, U shade, Herculite XR의 L, LY shade는 ${\Delta}E^*$값이 3.3 이상으로 나타났다. 4. Z100, Prisma TPH, Tetric, Silux Plus에서는 복합레진보다 shade guide가 더 높은 $L^*$값을 보이는 경향이 나타났으며, Herculite XR에서만 복합레진이 더 높은 $L^*$값을 나타냈다. 5. 모든 시편에서 $b^*$ 값은 (+)로 관찰되었고, Z100, Prisma TPH, Tetric, Silux Plus의 shade guide는 복합레진에 비해 높은 $b^*$값을 보였다. 6. 모든 시편에서 $a^*$값은 (-)로 관찰되었고. Herculite XR 및 Silux Plus에서는 복합레진이 shade guide 에 비 해 낮은 $a^*$값을 나타냈다.

• Herbal Formula Science
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• v.20 no.1
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• pp.51-65
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• 2012

Objectives : In this study the antidepressant effects of mixture of Lycii Radicis Cortex and Gardeniae Fructus on the change of HPA-Axis and Catecholamine system was investigated Methods : The forced swimming test was performed. The expression of CRF, c-Fos in the PVN, and TH in the VTA and LC were measured with immunohistochemical method. And the experimental groups were divided into the Extraction after Mix group(A) and Mix after Extraction group(B). The effects of both group were compared. Results : The duration of immobility in the FST was decreased significantly in three groups except B100(P<0.01). B100 was shown the significant increase(P<0.05). The expression of CRF in PVN was decreased significantly in all group(P<0.05~P<0.01). The expression of c-Fos in PVN was decreased in A100, A400 and was increased significantly in B100, B400(P<0.05). The expression of TH in VTA and LC were decreased significantly in all group(P<0.001). Conclusions : Effects of Extraction after Mix group(A) and Mix after Extraction group(B) on the HPA-Axis system and Catecholamine system were validated.

• KSBB Journal
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• v.24 no.6
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• pp.556-562
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• 2009

The biological treatment of TNT-containing wastewater, known commonly as pink water, was investigated using a stirred tank reactor with Stenotrophomonas maltophilia OK-5 bacterial culture. S. maltophilia OK-5 exhibited effective degradation of TNT contained in pink water, completely degrading TNT (100 mg/L) within 6 days of incubation. The dark-red brown color derived from Hydride-Meisenheimer complex became more pronounced during the incubation period, which was determined quantitatively. High-pressure liquid chromatography was used to measure residual TNT, which also resolved the metabolic intermediates (i.e., 2,4-dinitrotoluene, 2,6-dinitrotoluene and 2,4-dinitro-6-hydroxytoluene). Gas chromatography-mass spectrometry was used to verify these intermediates. Quantification of the nitroreductase (pnrB) gene isolated from S. maltophilia OK-5 growing in pink water was performed with real-time PCR. The amount of pnrB gene copies increased to $10^3$-fold after 5 days of incubation time.

• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.397-408
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• 2007

Diplexer is one of core devices needed to communicate with satellite using single ground antenna by separating uplink and downlink signal. This paper presents the design of the S-band diplexer for LEO TT&C application, especially for KOMPSAT (KOrea Multi-Purpose SATellite). To cope with requirements such as high handling power, low insertion loss, air-cavity resonator with high quality factor was considered as one of design drivers. Design was started with predicting unloaded Q and equivalent circuit from the structure of air-cavity resonator. For the convenience of adjustment, the coupling factor placed between resonators was estimated from COTSEM (Electro-Magnetic) simulator, EESOF $ADS^{TM}$, and expressed with 2-order polynomial regression. To improve the isolation between transmitting part (Tx) and receiving part (Rx), the inductive and capacitive attenuation poles were inserted between $4^{th}\;and\;6^{th}$ resonator respectively. The fabricated diplexer consists of two bandpass filters and each filter has eight resonants. From the measurement, it was shown that major requirements such as 0.5dB of insertion loss, 20dB of return loss and 100dB of isolation were fully satisfied within passband.

• KSBB Journal
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• v.9 no.5
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• pp.506-511
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• 1994

Antimicrobial activity of methanol extract and fraction from mugwort leaves(Artemisia princeps val. orientalis) was investigated for the screening of natural antiwucroblal components. By using agar diffusion method, ethyl acetate(EtOAc) layer fractionated from methanol extract of mugwort leaves showed the highest inhibitory effects against tested microorganisms. The ortho-coumaric acid(200∼600ppm) isolated from EtOAc layer showed strong antibacterial activities for Bacillus subtilis and Salmonella typhimurium. As derivatives of o-coumaric acid, antibacterial activity of para-coumaric acid was 1.2∼1.7 fold higher than that of o-coumaric acid. Three types of coumaric acids strong inhibited the growth of B. subtilis in the culture medium. Growth of S. tyhimurium, P. aeruginosa and S. aureus were effectively inhibited by o-, m- and p-coumaric acids, respectively. Minimum inhibitory dose of p-coumaric acid for B. subtilis was $\100∼200mu\textrm{g}$/paper disk.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.12
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• pp.1766-1771
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• 2003

House made differential mobility analyzer(DMA) is calibrated with NIST SRM 1691(300 nm PSL). Then the particle size and uncertainty for differential mobility analyzer(DMA) using the NIST SRM 1963(100 nm PSL). In result, calibration of prototype DMA is measured using 300 nm NIST SRM 1691, then sheath air flow was corrected 126.67 ㎤/s. Corrected sheath air flow is used in uncertainty measurement of prototype DMA. Uncertainty analysis is performed using NIST SRM 1963(100 nm PSL). The experimental result shows that NIST SRM 1963 is measured as 102.17 nm with a type A uncertainty of 0.33 nm.

• Korean Journal of Veterinary Research
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• v.59 no.3
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• pp.157-160
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• 2019

The production of rmtB-encoded 16S rRNA methylases has emerged as a novel mechanism promoting high-level resistance toward aminoglycosides in Gram-negative bacteria. Between 2015 and 2017, 636 distinct commensal Escherichia (E.) coli isolates were collected from different farms in South Korea to determine the prevalence and molecular characteristics of rmtB. The positive rates of rmtB between all the isolates and amikacin-resistant isolates were 1.1 and 100%, respectively. High-level aminoglycoside resistance could be transferred by conjugation from rmtB-positive donors to higher amikacin-resistance efficacies. This is the first report of 16S rRNA methylase-encoding genes in E. coli isolated from food-producing animals in Korea.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.231-234
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• 2001

위성방송 수신을 위한 S-band용 LNB를 유전율3.48, 기판두께 0.762mm의 기판을 사용하여 NF=0.9 dB, 변환이득 56dB, Gain Flatness +0.7dB/27MHz을 만족하도록 설계하였으며 대역통과필터는 원하는 대역내에서 삽입손실 -2dB, 반사계수 -l2dB 이하의 결과를 얻었다. 발진기는 3.62GHz에서 6.17dBm의 출력을 나타내었으며 위상잡음은 중심주파수 3.62GHz의 100kHz offset 지점에서 -98 dBc/Hz의 특성을 얻었다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.259-261
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• 2003

얼랑(Erlang) B 이론에 의해 산출된 목표호손율이 보장된 값이라고 믿고 있으나 신뢰도에 따른 분석결과 보장정도가 50% 수준 밖에 미치지 못하는 결과를 알 수 있다. 신뢰도라는 것은 목표 호손율(Block Rate)을 통해 회선을 산출하였을 때 실측호손율을 어느 비율까지 수용을 할 수 있는지에 대한 기준이다 . 신뢰도를 적용한 결과 얼랑 B 이론은 평균에 의해 값을 산출하는 것이 때문에 실측호손율이 얼랑 B 이론에 의해 산출된 호손율 이상일때는 GoS를 100% 보장할 수가 없다. 그러므로 회선산출하는데 있어서 신뢰도를 추가하여 보정된 얼랑B Table을 산출하는 방법을 제시한다.