• Journal of Information Processing Systems
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• 제5권3호
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• pp.117-130
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• 2009

By providing ubiquitous Internet connectivity, wireless networks offer more convenient ways for users to surf the Internet. However, wireless networks encounter more technological challenges than wired networks, such as bandwidth, security problems, and handoff latency. Thus, this paper proposes new technologies to solve these problems. First, a Security Access Gateway (SAG) is proposed to solve the security issue. Originally, mobile terminals were unable to process high security calculations because of their low calculating power. SAG not only offers high calculating power to encrypt the encryption demand of SAG's domain, but also helps mobile terminals to establish a multiple safety tunnel to maintain a secure domain. Second, Robust Header Compression (RoHC) technology is adopted to increase the utilization of bandwidth. Instead of Access Point (AP), Access Gateway (AG) is used to deal with the packet header compression and de-compression from the wireless end. AG's high calculating power is able to reduce the load on AP. In the original architecture, AP has to deal with a large number of demands by header compression/de-compression from mobile terminals. Eventually, wireless networks must offer users "Mobility" and "Roaming". For wireless networks to achieve "Mobility" and "Roaming," we can use Mobile IPv6 (MIPv6) technology. Nevertheless, such technology might cause latency. Furthermore, how the security tunnel and header compression established before the handoff can be used by mobile terminals handoff will be another great challenge. Thus, this paper proposes to solve the problem by using Early Binding Updates (EBU) and Security Access Gateway (SAG) to offer a complete mechanism with low latency, low handoff mechanism calculation, and high security.

• 생명과학회지
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• 제19권7호
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• pp.845-851
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• 2009

본 연구는 5-L 발효기를 이용하여 재조합 고스트 박테리아(E.coli $DH5{\alpha}$/ pHCE-InaN-(enolase, GAPDH, sagA or piaA)-ghost 37 SDM) 백신의 산업화를 위해 탄소원 공급조건, 교반속도, 산소공급 조건등의 최적 배양조건과 고스트 박테리아 발현 유도를 위한 온도조절 시점과 그에 따른 발현효율 최적화를 조사하기 위해 수행하였다. 각각 다른 4종의 항원 유전자를 보유한 고스트 박테리아를 LB 배지를 이용하여 배양한 결과 모두 1 g / 1 glucose, 300 rpm, 1vvm에서 최대 균주 성장을 나타내었다. 고스트 박테리아 생성 효율의 경우 초기 대수증식기(OD$_{600}$=1.0)에서 고스트 발현을 유도했을 때 각각 최대효율인 99.99%를 나타내었으나 증기 대수증식기(OD$_{600}$=2.0)와 말기 대수증식기 (OD$_{600}$=3.0)에서는 고스트 박테리아 생성이 낮은 효율을 나타내었다. 또한 SDS-PAGE 와 western blot를 이용하여 각각 다른 4종의 항원 단백질 발현 여주를 확인한 결과 enolase (78kda), GAPDH (67kda),sagA(26kDa), piaA(26kDa)에서 항원 단백질 band를 확인할 수 있었다. 따라서 본 연구결과 확립된 배양 조건과 발현효율 최적화 조건은 연쇄구균증 질병에 대해 E.coli를 이용한 고스트 박테리아 백신이 양식 산업에 있어 상업적으로 유용한 백신의 최적생산을 위해 사용 될 수 있을 것으로 사료된다.

• 한국미생물·생명공학회지
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• 제23권6호
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• pp.687-694
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• 1995

Alkalophilic Bacillus sp. HJ-12 producing $\beta $-1, 4-D-arabinogalactanase was isolated from soil in the alkalic condition, pH 10.0. $\beta $-1, 4-D-arabinogalactanase was maximaly produced in the medium consisting of 2% soybean arabinogalactan (SAG), 0.5% yeast extract, 0.5% polypeptone, 0.5% NaCl, 0.1% K$_{2}$HPO$_{4}$, 0.02% MgSO$_{4}$$\cdot $7H$_{2}$O, 0.1% Na$_{2}$CO$_{3}$ under the aerobic condition (pH 8.2). $\beta $-1, 4-D-arabinogalactanase is inducible enzyme so that its activity has been increased 10 fold in the SAG medium than in the glucose medium. Through the ammonium sulfate precipitation, DEAE- Sephadex A-50 ion chromatography, and Sephadex G-75 gel chromatography procedures, this enzyme was purified with a single protein of 11% vield and 110 fold's purity. $\beta $-1, 4-D-arabinogalactanase is endo type enzyme producing ollgosaccharide from SAG.

• 전기학회논문지
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• 제58권8호
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• pp.1544-1550
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• 2009

In this paper, a new single phase voltage sag/swell compensator using direct power conversion is proposed. A new compensator consists of input/output filter, series transformer and direct ac-ac converter, which is a single-phase back-to-back PWM converter without dc-link capacitors. Advantages of the proposed compensator include: simple power circuit by eliminating dc link electrolytic capacitors and thereby, improved reliability and increased life time of the entire compensator; simple PWM strategy or compensating voltage sag/swell at the same time and reduced switching losses in the ac-ac converter. Further, the proposed scheme is able to adopt simple switch commutation method without requiring complex four-step commutation method that is commonly employed in the direct power conversion. Simulation and experimental results are shown to demonstrate the advantages of the new compensator and PWM strategy. A 220V, 3kVA single-phase compensator based on the digital signal processor controller is built and tested.

• 조명전기설비학회논문지
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• 제24권9호
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• pp.165-171
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• 2010

There are many researches on Power Quality Device to protect the critical load and power system as the nonlinear load and precision load are adopted into the power system recently. To analyze the voltage compensation of voltage sag and voltage swell by DVR, which is connected to the important load in series, this paper shows PSCAD/EMTDC simulation and its verification by comparing with the actual DVR output of 2MVA. DVR control scheme in this paper is applicable to compensate single-phase, 2-phases or 3-phases voltage sag as well as DVR for distribution system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.36-38
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• 2003

In this paper, It was evaluated that the customer's effects of momentary voltage sag in power distribution system considering reclosing interval. Above all, power quality problems were discussed widely, various international standards about power quality were compared to each other. after the continuous voltage sag waves of power distribution system on fault were induced, the experimentation about voltage sag for critical load was performed using source simulator. The results of experimentation were displayed as the form of 2 and 3-dimensional CBEMA Curve.

• 국제강구조저널
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• 제18권5호
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• pp.1801-1817
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• 2018

This paper presents the numerical parametric analysis on the loading capacity of Channel purlins with screw-fastened sheeting, in which the effects of anti-sag bar and corrugated steel sheet on the ultimate capacity are studied. Results show that the setup of anti-sag bars can reduce the deformations and improve the ultimate capacity of C purlins. The traditional method of setting the anti-sag bars in the middle of the web is favorable. The changing of sheeting type, sheeting thickness and rib spacing has significant effects on the ultimate capacity of C purlins without anti-sag bars, compared with those with anti-sag bars. The proposed design formulas are relatively consistent with the calculations of EN 1993-1-3:2006, which is different from those of GB 50018-2002.

• 한국식품영양학회지
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• 제10권4호
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• pp.497-502
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• 1997

대두 및 두유박의 주요 다당류인 대두 arabinogalactan(SAG)을 이용하여 갈락토올리고당을 생산하고자 SAG 가수분해효소인 $\beta$-1, 4-galactanase를 이용하여 대두 갈락토올리고당(SOS)의 생산조건 및 그 특성을 연구 검토하였다. SOS는 SAG 1%(w/v), pH 8.0, 5$0^{\circ}C$인 조거에서 $\beta$-1, 4-galactanase를 20unit/g SAG를 첨가하여 24-40시간 반응하여 생산하였다. 생산된 SOS 용액(75%)은 11,000cp의 점도를 나타내어 같은 농도의 설탕용액 140cp의 값에 비해 80배 큰 값을 나타내었다. 점도의 온도의존성은 5$0^{\circ}C$ 이하에서는 온도의존 함수(B) 값이 11,037 cp.K로 설탕용액의 2,760보다 약 4.6배 크지만 5$0^{\circ}C$ 이상에서는 3,400으로 큰 차이를 보이지 않았다. 또한 올리고당의 농도가 50 Brix 이하에서는 설탕용액의 점도 20-30 cp와 유사한 20-40cp로 차이를 보이지 않지만 농도가 증가함에 따라 차이가 커져 Brix 70에서는 1,280cp로 설탕용액의 90cp보다 15배 높은 값을 나타내었다. 생산된 SOS는 pH 및 온도에 대해 매우 안정하여 pH 3,14$0^{\circ}C$인 조건하에서도 분해로 인하여 생산되는 galactose가 없었다.

• Parasites, Hosts and Diseases
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• 제53권1호
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• pp.125-128
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• 2015

The prevalence and genotype of Toxoplasma gondii infection in dogs in Henan Province, Central China was investigated. A total of 125 blood samples were collected from pet dogs during April to June 2013, and all samples were examined by indirect hemagglutination antibody test (IHA) and nested PCR. The overall T. gondii prevalence in pet dogs was 24.0% (30/125), with 20.8% (26/125) in IHA and 10.4% (13/125) in PCR, respectively. No statistical associations were found between animal gender and age and the prevalence of T. gondii infection. Thirteen positive DNA samples were genotyped using 11 PCR-RFLP markers, including SAG1, (3'+5') SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. Of these, only 2 samples were genotyped with complete data for all loci, and a novel genotype (type III at SAG3 and GRA6 loci, and type I at other loci) was identified. This is the first report of genetic characterization of T. gondii infection in dogs in China.

• 조명전기설비학회논문지
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• 제22권10호
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• pp.41-48
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• 2008

본 연구에서는 전압품질에 민감한 설비를 위한 3상 Z-소스 동적 전압 보상기(Z-DVR : Z-Source Dynamic Voltage Restorer)를 제시하였다. 제안된 시스템은 수동필터와 Z-소스 토폴로지의 직렬형 능동필터로 구성된다. Z-DVR의 ESS(Energy Storage System)로는 친환경적인 고분자 전해질 연료전지(PEMFC : Proton Exchange Membrane Fuel Cells)를 사용하였다. 고조파 검출은 동기좌표계의 $i_{d}-i_{q}$ 이론에 의하였으며, 부하전압 보상을 위하여 PI제어를 사용하였다. 3상 전원이 모두 전압 sag가 발생하는 경우, PSIM에 의하여 제안된 방법과 배터리 스택을 적용하는 종전의 방법에 대하여 시뮬레이션을 수행하였으며, 전압 보상성능이 유사함을 알 수 있었다. 또한 전압 sag와 swell이 동시에 또는 독립적으로 발생하는 다양한 전원 조건하에서 제안된 시스템의 전압 보상 성능과 전압에 대한 %THD(%Total Harmonic Distortion)를 검토하였다.