• 약학회지
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• 제32권6호
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• pp.377-385
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• 1988

The biologically active component of licoris(Glycyrrhizae Radix L.) is considered to be glycyrrhetinic acid, an aglycone of glycyrrhizin, on the basis of chemical and pharmacological studies. The present study was undertaken to investigate the effect of glycyrrhetinic acid on the hepatic morphine-6-dehydrogenase activity, which catalize morphine to morphinone. Morphine-6-dehydrogenase was further purified by centrifugation, $(NH_4)_2SO_4$ fractionation, sephadex G-100, hydroxyapatite column. Hepatic morphine-6-dehydrogenase activity was significantly decreased by the treatment of glycyrrhetinic acid. When effect of glycyrrhetinic acid on the hepatic morphine-6-dehydrogenase was investigated in vitro, it was powerfully inhibited the enzyme activity with dose-dependent manner. From the above results, glycyrrhetinic acid inhibits hepatic morphine-6-dehydrogenase activity and decreases the morphine induced harmful side effects.

• Archives of Pharmacal Research
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• 제17권2호
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• pp.109-114
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• 1994

The role of sex homones in hepatic lipid peroxidation, and in hepatic adehyde odidase and xanthine oxidase activites were investigated using rat liver homogenates. It was observed that male rt had a significantly greater content of malondialdehyde in liver than female. Among the sex hormones tested, estradiol, one of female hormones, markedly inhibited the formation of lipid peroxides in liver tissues in vitro. Especially, the inhibitory effect of estradiol appeared more remarkably in Fe-induced lipid peroxidation. The hepatic xanthine oxidase activity was decreased about 15% by $10\;^6\;M$ estradiol, wherease, the adehyde oxidase activity was almost completely disappeared at the same concentration of estradiol. It implies that sex differences in lipid peroxidation is attributed to the suppression of radical generating system by estradiol.

• Archives of Pharmacal Research
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• 제22권5호
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• pp.520-523
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• 1999

We have been screening anti-HIV integrase compounds from Korean medicinal plants by using an in vitro assay system which is mainly composed of recombinant human immunodeficency virus type 1 integrase and radiolabeled oligonucleotides. From the above screening, the aqueous methanolic extract of the roots of Agastache rugosa exhibited a significant activity. Bioactivity-guided chromatographic fractionation of the methanolic extract resulted in the isolation of rosmarinic acid. The structure of the compound was determined by spectroscopic data and by the comparison with the reported values. The $IC_{50}$ of the rosmarinic acid was approximately $10{\mu}g/ml$ against HIV integrase.

• 약학회지
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• 제31권3호
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• pp.149-153
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• 1987

Pyrazinamide, an amide of pyrazinoic acid, is widely used in combination with other drugs for the treatment of tuberculosis. It was attempted to observe the effect of pyridoxal on the pyrazinamide induce hyperuricemia in this study. It was observed that the values of serum transminases were not changed in mice injected pyrazinamide and pyrazinoic acid, respectively (100, 200, and 300mg/kg) compared with control. Blood urate levels were increased in mice treated with these drugs in a dose dependent manner. After pyrazinoic acid was administered intraperitoneally at a dose of 300mg/kg pretreated with 50mg/kg of pyridoxal once daily for 4 days, the blood levels of uric acid and pyrazinoic acid were decreased significantly.

• Archives of Pharmacal Research
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• 제18권1호
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• pp.56-59
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• 1995

The effect of ceruloplasmin or copper ion on hepatic xanthine oxidase activity and type conversion was investigated using rat liver in vitro. It was observed that ceruloplasmin increased xanthine oxidase type conversion depending on duration of its storage. Xanthine oxidase (type O) activity and type conversion in incubation mixture was increased by the addition of heated celuroplasmin in a temperature dependent manner. The type conversioin of xanthine oxidase induced by heated ceruloplasmin was retumed to normal by the tratment with DTT or penicillamine. The effect of copper ion on type conversion of xanthine oxidase was similar to that of heated ceruloplasmin.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.849-853
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• 2002

인터넷 사용자 수의 급격한 증가로 인터넷 서비스 보급이 대중화됨에 따라 인터넷 텔레포니 기술이 전기통신사업자 및 인터넷 서비스 사업자들의 주요 이슈가 되고 있다. 인터넷 텔레포니 서비스를 위한 호처리 프로토콜을 표준화하기 위해 1999년 9원 IETF산하 SIP WG이 구성된 이래, RFC2543 bis 문서들이 계속 소개되었으며, 2002년 7월초 bis-09문서를 기반으로 RFC3261 SIP 표준이 제정되었다. 본 논문에서는 SIP 메시지 전송을 위해 초창기에 사용하던 Strict 라우팅 방법과 RFC3261에서 사용하는 Loose 라우팅 방법을 비교하고, RFC3261 SIP 표준에서 제공하는 둘 간의 호환성 문제 해결 방안을 분석한다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 추계학술발표논문집 (중)
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• pp.1503-1506
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• 2002

기존 가입자망은 다양한 멀티미디어 서비스 트래픽에 대해 병목으로 작용하였으며 이에 대한 대안으로 광가입자망 기술 대두되었다. 광가입자망은 초기 설치비용이 매우 고가이기 때문에 기술 개발과 설치가 지연되었으나, 비용대비 효율성이 좋은 Passive Optical Network(PON) 기술이 개발됨에 따라 활기를 띠고 있다. 본 고에서는 MPLS/IP 백본으로 연결되는 Ethernet-PON 기반의 광가입자망에서, L2/L3 MPLS 기반의 망사업자가 제공하는 VPN 기술 개발을 위해 Optical Network Unit(ONU) 및 Optical Line Terminal(OLT)에서 지원해야 되는 기능에 대해 연구한다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2016년도 춘계학술발표대회
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• pp.195-196
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• 2016

최근 SLA를 자동으로 관리하고자 하는 국내 외에서 연구가 진행되고 있으나, 유지보수 측면과 과금 체계 자동화 측면에서 완성도가 낮은 편이다. 그러한 문제를 해결하기 위한 모바일 클라우드 서비스 환경에서 자동화된 서비스 수준 협약을 제공하기 위한 구조를 제안한다. 본 구조는 클라우드 서비스 브로커를 기반으로 서비스 제공자와 서비스 사용자를 연결하며, 주로 제공자 측면에서 작성되던 SLA를 사용자 측면도 고려할 수 있도록 하여, 균형을 이룰 수 있을 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2485-2487
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• 2000

In this paper, we use a fuzzy algorithm to detect and diagnose the error which is caused by time delay of the computer-controlled system. Generally, a computer-controlled system is composed of computer and process. And they communicate the data each other. In data communication, error occurs by some reasons, such as noise, disturbance, hardware defect, etc. Time delay is one of the reasons. And time delay makes it difficult to distinguish whether the system really has a problem or not. Therefore, we need to detect and diagnose the error from time delay. For difficulty of modeling and ambiguity of classification, we use a fuzzy algorithm. To verify the better performance of the proposed algorithm, we exemplified by some simulation results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.420-422
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• 1998

In this paper, we propose a position-speed control of servo system with a state estimator. And also we utilized two mass modelling in order to deals with real system accurately. The overall control system consists of two parts: the position-speed controller and state estimator. The Kalman filter applied as state - feedback controller is an optimal state estimator applied to a dynamic system that involves random perturbations and gives a linear,unbiased and minimun error variance recursive algorithm to estimate the unknown state optimally. Therefore we consider the error problem about the servo system modelling, the measurement noise at low-speed ranges a stochastic system, and implement a optimal state observer. Performance of the proposed state estimator are demonstrated by computer simulations.