• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.127-131
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• 2007

본 논문에서 제안하고자 하는 IPTV 채널캐슁 서비스는 IPTV 서비스의 품질요소인 QoE(Quality of Experience)의 개선을 목적으로 하고 있다. IPTV 채널캐슁 방법은 IPTV 서비스가 실시간 방송 및 VOD(Video On Demand)등 다양한 패턴의 서비스를 선택하는 사용자의 채널요구 패턴을 반영한 인접채널(adjacent-channel)을 멀티캐스트하면, 사용자의 채널전환요구시 제어메시지 전송 및 스위칭에 소요되는 대기시간을 줄여 사용자의 채널전환지연시간을 개선할 수 있다. 이를 위하여 본 논문에서는 LRFU(Least Recently Frequently Used) 알고리즘에 기반한 MCA(Multicast Channel Agent)을 제안하며, MCA을 구성모듈에 대한 설명을 기술한다.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.209-212
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• 1986

$\alpha$-Amylase gene of Bacillus amyloliquetaciens was cloned on plasmid YEp13, S. cerevisiae-E. coli shuttle vector. Hybrid plasmid pTG17, carrying $\alpha$-amylase gene of B. amyloliquefaciens, was transformed to E. coli and the expression of it in yeast was investigated. This plasmid was unstable in E. coli and produced two minor plasmids, pTG17-1 and PTG17-2, which resulted from the segregation of it. Transformant of S. cerevisiae MC16 with pTG17-1 plasmid was not appeared on SD medium because of the Leu2 gene defection. S. cerevisiae could be transformed by the hybrid plasmid, and $\alpha$-amylase activity of the yeast transformant was detected by somogyi-Nelson method and agar diffusion method.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.518.2-519
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• 1986

토양으로부터 분리한 질소고정균인 Klebsiella pneumoniae NFB320의 chromosomal DNA를 BamHI으로 절단하여 동일한 제한효소로 절단한 pBR322에 ligation시켜 E. coli HB101에 형질전환을 행하여 pullulanase activity를 나타내는 clone을 얻어내었다. 이 형질 전환체로부터 분리한 pullulanase 유전자가 재조합된 plasmid DNA는 약 10kb의 DNA단편을 가지고 있었으며, 재조합된 plasmid로부터 생산되는 pullulanase의 특성은 최적 활성 pH가 6.0이며, 효소의 pH안정성은 5-10이었다. 또한 형질 전환체로부터 생산되는 pullulanase의 localization,효소활성에 영향을 미치는 온도안정성 둥을 조사하였다.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.257-265
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• 1996

Previously, we demonstrated that estradiol (E$_2$) was produced by medium sized follicles of Rana nigromaculata and Rana dybowskii in vitro. Present experiments were carried out to determine when the growing follicles have obtained the ability to produce E$_2$. Follicles in different growth stages were isolated and cultured for 6 hours in the presence or absence of frog pituitary homogenates (FPH, 0.1 pituitary/2m1) or various steroid precursors (200 ng/2m1). levels of progesterone (P$_4$), 17 -hydroxyprogesterone (17$\alpha$-OHP), androstenedione (AD), testosterone Cr) or E$_2$ in the medium were measured by RIA. The smallest follicles failed to produce steroids, whereas the smaller follicles produced considerable amounts of steroids (211 pg/follicle), and the medium sized follicles produced a large amounts of steroids (1653 pg/follicle) in response to FPH. Addition of pregnenolone (P5) resulted in a marked increase in P$_4$ but not in other steroids by the smallest follicles whereas the treatment resulted in a marked increase in P$_4$, 17$\alpha$-OHP, AD, T and E$_2$by the smaller and medium follicles. When the amounts of steroids are calculated on the basis of unit surface area (pg/mm$_2$), the ability of the smallest follicles to produce P$_4$ from P5 was similar to those of smaller and medium sized follicles. However, the smallest follicles failed to metabolize P$_4$ to other steroids whereas the smaller and medium follicles did. Taken together, the data suggest that the smallest follicles do not response to FPH in terms of steroid production but they have capacity to convert P5 to P$_4$ and that the smaller follicles have potential to produce E$_2$ although much less efficient than medium sized follicles.

• Proceedings of the CALSEC Conference
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• 2001.02a
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• pp.357-362
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• 2001

ㆍ 정보화 사회로의 급격한 전환으로 생채인식 시스템이 공공 및 개인의 차세대 보안 솔루션으로 각광 받을 것으로 예상. ㆍ 홍채 인식은 타 생체인식에 비해 변별도가 월등히 높아 미래형 생체인식 기술로 부각될 것으로 기대.(중략)

• Information Systems Review
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• v.16 no.3
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• pp.135-160
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• 2014

Most Social Network Service (SNS) provide online chat, video and file sharing, blogging and others. Because of this advantage, people depend on SNS to communicate with others. However, recently SNS encourage people to reveal too much information broadly so SNS users are concerned about privacy invasion and data spill. They also feel fatigue in process of touching people they don't know while using SNSs. That is the reason why they attempt to switch from opened SNS to Closed SNS. Therefore, the purpose of this study is to empirically investigate and analyze the effect of the factors on the SNS users' switching behavior when using SNS. To accomplish this purpose, this research adopted "Push-Pull-Mooring (PPM)" framework. The PPM is proposed by population geologist, who used it to explain the incentives of demographic migration. Following PPM model, this research empirically examines the three categories of antecedents for SNS switching intention toward closed SNS: push (i.e., weak connection, privacy concern, relative complexity), pull (i.e., enjoyment, belongingness, peer influence), mooring (i.e., SNS fatigue, user resistance) factors. The survey was conducted for 285 users on SNS communities in Korea. The results of this study are as follows; First, wear connection and privacy concern are significantly related to SNS switching intention. Second, enjoyment and belongingness are significantly related to SNS switching intention. Finally, the results show that SNS fatigue has a moderating effect on the links between push factors and SNS switching Intention. Also, user resistance has a moderating effect on the links between pull factors and SNS switching Intention. These findings contribute to the SNS literature both theoretically and practically.

• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.361-366
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• 2019

Isorhamnetin 3-O-glucoside, a member of the flavonol group, has been reported to be effective for inflammatory and ulcer, as well as to alleviate diabetic complications such as neuropathy, nephropathy and retinopathy. Isorhamnetin 3-O-glucoside has been extracted from several plants. Biotransformation is a valuable tool, which is used to produce value-added chemicals with inexpensive compounds. To synthesis isorhamnetin 3-O-glucoside from quercetin, two genes (PGT E82L and ROMT-9) were introduced into Escherichia coli, respectively. In order to synthesis isorhamnetin 3-O-glucoside from quercetin, a co-culture fermentation system was developed by optimizing the medium and temperature for biotransformation, the cell mix ratio, Isopropyl-β-ᴅ-thiogalactoside induction time, and quercetin feed concentration. Finally, isorhamnetin 3-O-glucoside was biosynthesized up to 181.2 mg/L under the optimized biotransformation condition, which was higher 4.7 times than previously reported (39.6 mg/L).

• Digital Contents
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• no.2 s.81
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• pp.32-37
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• 2000

XRP(eXtended Resoure Planning)를 기반으로 ERP 시스템을 e-비즈니스 인프라스트럭처로 전환하려면 제품 선택 과정의 변화가 필요하다. ERP 기반의 인프라스트럭처를 구현하여 e-비즈니스 전략을 지원하려는 중소규모 소매업체를 대상으로 제품 선택 기준을 제시한다. 그러나 기술적인 또는 기능적인 변화에 따라 개선된 프레임웍은 다른 업종에도 적용될 수 있다.

• Proceedings of the CALSEC Conference
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• 2001.02a
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• pp.391-404
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• 2001

e-business의 현재 · EDI - 대규모 조직에 국한되어 있음. · 많은 기업들이 감당하기에는 구현비용이 비싼 편. · 진입에 고비용이 필요, 유연성결여. · 공급망에 있어 비즈니스 적인 연계가 되지 않음 - 산업군의 경계 외적으로 메시지 교환이 필요 · 특정 산업에서 XML 사용이 시작되고 있음 - EDI에서 XML로의 전환이 시도되고 있음. · 일반적인 요구사항에 대한 합의가 필요한 시점 · 일반적이고 공통적인 infrastructure의 부재는 상호간의 통신에 있어 비호환적이고 배타적인 고립을 의미한다.(중략)

• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.336-341
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• 2003

1.연구배경 사회환경이 변화하고 정보통신기술 인프라가 성장함에 따라, 전통적 교수학습 방법에서 e-러닝, 사이버, 교육, 온라인 교육 등으로 불리는 디지털 기반 교육으로 패러다임의 전환이 이루어지고 있으며, 우리나라의 경우 초고속 인터넷망이 잘 구축되어 교육훈련 목적의 콘텐츠 및 학습과정을 효과적으로 전달할 토대를 갖추고 있다.(중략)