• Microbiology and Biotechnology Letters
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• v.28 no.4
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• pp.223-227
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• 2000

A novel two-step acetone treatment method was developed to enhance the enantioselectivity of Candida rugosa lipase (CRL) toward the hydrolysis of racemic naproxen methyl ester. The acetone-teated CRL was considerably more enantioselective than the crude CRL, yielding an enantiomeric excess of 98~100%. The crude and acetone-treated CRLs were subjected to anion exchange chromatography, and their chromatography profiles were compared. In consequence, both chromatography profiles were found to be almost identical, resulting in two separate lipase peaks (lipase A and B). The lipase B, which is known to be less enantioselective, was treated with acetone using a two-step treatment method. The enantioselectivity of acetone-treated lipase B was dramatically increased, yielding an enantiomeric excess of 99%.

• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1583-1590
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• 2011

A Certificate Revocation List(CRL) should be distributed quickly to all the vehicles for vehicular communications to protect them from malicious users and malfunctioning equipment as well as to increase the overall security and safety of vehicular networks. Thus, a major challenge in vehicular networks is how to efficiently distribute CRLs. This paper proposes a Multimedia Object Transfer(MOT) protocol based on CRL distribution scheme over T-DMB infrastructure. To complete the proposed scheme, a handoff method, CRL encoding rules based on the MOT protocol, and relative comparison are presented. The scheme can broaden breadth of network coverage and can get real-time delivery with enhanced transmission reliability. Even if road side units are sparsely deployed or, even not deployed, vehicles can obtain recent CRLs from T-DMB infrastructure effectively.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.73-75
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• 2012

공인인증서는 온라인상에서 금융거래, 전자상거래, 전자정부 등에서 본인확인을 위한 수단으로 사용되고 있다. 공인인증서의 유효성을 확인하기 위한 방법 중 하나인 CRL(Certificate Revocation List) 검증방법은 실시간으로 검증하기 어렵기 때문에 공인인증서가 부정하게 사용될 수 있다. 본 논문에서는 해쉬값을 이용하여 CRL 검증방식에서 효력이 정지된 인증서의 정보만을 빠르게 갱신하는 방법을 제안하고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.676-678
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• 2001

공개키 기반 인증시스템에서 사용자의 실수로 비밀키가 노출되었거나 자격의 박탈, 유효기간 만료 등의 이유로 인증서를 폐지해야 할 경우가 있다. 이에 따라서 각 사용자는 수신한 인증서가 유효한 것인지를 확인해야만 한다. 이 인증서 폐지 여부를 확인하는 방법으로는 CRL, Delta-CRL OCSP 등의 방식이 개발되었다. 하지만 이 모든 방식에서의 인증서 유효성 검증은 실시간으로 처리해야 하므로 많은 통신량을 발생시키는 문제점을 가지고 있다. 본 논문에서는 CRL관리의 문제점인 전송시점 차이에 따른 무결성 문제와 실시간 처리를 인한 서버와 네트워크 과도한 트래픽 발생을 해결한 FM Subcarrier Broadcasting을 이용한 효율적인 CRL 구축방안을 제안하였다.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.11-18
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• 1989

This study was undertaken to obtain basic data of the sternal development in Korean native cattle from the earliest sternal formation to the ossification using histological and histochemical methods. Thrity three sterna were collected from a series of embryos and fetuses ranging from 11 to 225mm (estimated age 37~120days) in crown rump length. The bilateral sternal bars were observed in the 2nd group(CRL 21~3mm) of Korean cattle embryos. Those bars initiated to be fused in the 3rd group (CRL 31~4mm) and completed in the 7th group(CRL 71~80mm). The ossification centers were detected in the 8th group(CRL 81~90mm) also bilateral ossification centers were found in the same group. The typical epiphyseal plates, endochondral bone and calcium deposit were found in the 9th group(CRL 91~100mm). Osteocytes, osteoblasts, osteoclasts and myeloid cells appeared in ossification centers in the 10th group(more than CRL 101mm). The alcianophility responded markedly in the 9th group that was decreased and showed slightly positive reaction in territorial matrix of the 10th group. Marked positive reaction to PAS was observed in bony trabeculae in the 10th group. The positive reaction to calcium deposit by trichrome stain was observed initially in the hypertrophied zone of epiphyseal plate in the 9th group and was conspicuous in the calcified zone of epiphyseal plate in the 10th group. The 1st positive reaction to the von Kossa stain was observed in the 9th group.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.800-806
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• 2015

WAVE(Wireless Access in Vehicular Environments) system is wireless communication technology that vehicle sends and receives packets between vehicles or between vehicles and infrastructure in a high-speed mobile environment. In this study, we have designed and implemented a CRL(Certificate Revocation List) download protocol that is used to verify certificate revocation status of the other party when the vehicles communicate with WAVE system. This protocol operates over UDP. And to support security features, also, ECDSA(Elliptic Curve Digital Signature Algorithm) is used for mutual authentication and ECIES(Elliptic Curve Integrated Encryption Scheme) is used to ensure the confidentiality. Moreover, this protocol ensures the integrity of data by adding MAC(Message Authentication Code) to the end of packet and support the error and flow control mechanisms.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.691-697
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• 1996

The NR films were prepared with mixing of natural rubber latex(NRL) with various additives, and NR/CR films were prepared by blend ratio of chloroprene rubber latex(CRL). The swelling degree and the mechanical properties of these films were measured according to the procure time. As a result, optimum condition were showed the swelling degree : 80~85%, precure time : 48~60hrs., and tensile strength was reduced but elongation was increased as increasing the blend ratio of CRL. On the mechanical properties of films prepared by different dipping process in these optimum condition, the tensile strength and tear strength of NR/CR films by one dipping process are better than NR-d-CR films by two dipping process. The surface of these films were observed with scanning electron microscopy(SEM). It was found that phase separation was occured as increasing the blend ratio of CRL.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.4
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• pp.25-37
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• 2004

A certificate is expected to use for its entire validity period. However, a false information record of user and compromise of private key may cause a certificate to become invalid prior to the expiration of the validity period. The CA needs to revoke the certificate. The CA periodically updates a signed data structure called a certificate revocation list(CRL) at directory server. but as CA updates a new CRL at directory server. the user can use a revoked certificate. Not only does this paper analyzes a structure of CRL and a characteristic of certificate status conviction, OCSP method but also it proposes a new certificate status verification method adding an observer information in handshake process between user and server.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.760-768
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• 2004

The present study was undertaken to evaluate the accuracy of ultrasonography in early pregnancy diagnosis in goats. Ultrasonographic scanning with real time B-mode ultrasound machine having 5 MHz linear array transducer was performed on gravid uterus (n=24) obtained from slaughterhouse (Group I). Crown rump length (CRL) measured by ultrasound was found significantly different (p<0.05) with actual CRL measured after dissection in early pregnancy. However, age predicted by ultrasound through the measurement of CRL was found highly correlated (r=0.92) with age measured after dissection through CRL and the weight of fetus. Ages predicted by ultrasound through the measurement of trunk diameter (TD) and uterine diameter (UD) and ages measured after dissection were found highly and equally correlated (r=0.98) and did not differ significantly. Data from six does synchronized (Group II) with PGF2$\alpha$ (Estrumate) at 11 days apart were collected through ultrasound from 17 to 42 days post breding. The correlation between CRL and gestational age was high (r=0.97) in day 30 to 42 post breeding. A high coefficient of correlation (r=0.98) was also observed between predicated age by ultrasound and actual age calculated after kidding. The correlation between CRL and gestational age by the formula Y=(a+bX) i.e. Y=24.42+0.39 X where Y=gestational age and X=CRL, was recorded very high (r=0.99). Accuracy of ultrasonography was lowest on day 17 to 19 (66%) and reached 100% on day 34. Data from 30 does (group III) randomly subjected to only one time ultrasounds scanning to assess the accuracy of pregnancy diagnosis were also obtained. Ages predicted by TD and UD measurements were observed to be non-significantly different with actual age obtained after kidding and correlation between ages predicted by TD and UD measurement with actual age after kidding was found equally and highly correlated (r=0.98). The operator's accuracy in the whole experiment including all three groups was found to be 92%. The sensitivity was 93% and specificity was 86%. From the present study, it was observed that CRL was the most reliable parameter to find out gestational age in early pregnancy and the new formula derived was found very accurate to find out gestational age. TD and UD were also found to be equally reliable parameter to find out gestational age in mid and late stage of pregnancy through ultrasonography. It was concluded that ultrasonography by real time B mode with 5 MHz transrectal transducer was found to be reliable, safe and accurate and practicable means in diagnosing early pregnancy diagnosis as early as 25 days post breeding.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.231-237
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• 2003

공개키 기반 구조에서 과거 시점에 서명한 문서를 검증하기 위해서는 서명한 시점의 인증서의 상태정보를 확인하여야 한다. 하지만, 기존의 상태 정보 제공 메커니즘을 이용하여 과거 시점에 대한 상태 정보를 획득할 경우에는 여러 가지 문제가 발생할 수 있다. 본 논문에서는 이러한 문제점에 대하여 자세히 설명하고 이를 해결하기 위한 방법을 제시한다.