• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.852-858
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• 2008

An extracellular protease (Mc1) was isolated from the nematode-trapping fungus Monacrosporium cystosporium by gel filtration, anion-exchange, and hydrophobic interaction chromatographies. This protease had a molecular mass of approximately 38 kDa and displayed an optimal activity at pH 7-9 and $56^{\circ}C$ (over 30 min). Its proteolytic activity was highly sensitive to the serine protease inhibitor PMSF (phenylmethylsulfonylfluoride, 0.1 mM), indicating that it belonged to the serine-type peptidase group. The Michaelis constant ($K_m$) and $V_max$ for substrate N-Suc-Ala-Ala-Pro-Phe-pNA were $1.67{\times}10^{-4}\;M$ and 0.6071 $OD_{410}$ per 30 s, respectively. This protease could degrade a broad range of substrates including casein, gelatin, BSA (bovine serum albumin), and nematode cuticle. Moreover, the enzyme could immobilize the free-living nematode Panagrellus redivivus and the pine wood nematode Bursaphelenchus xylophilus, suggesting that it might playa role in infection against nematodes. The encoding gene of Mc1 was composed of one intron and two exons, coding for a polypeptide of 405 amino acid residues. The deduced amino acid sequence of Mcl showed 61.4-91.9% identity to serine proteases from other nematode-trapping fungi. Our results identified that Mcl possessed biochemical properties including optimal reaction condition and substrate preference that are different from previously identified serine proteases.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1221-1226
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• 2008

The soft rot bacterium Pectobacterium wasabiae is an economically important pathogen of many crops. A new phytase gene, appA, was cloned from P. wasabiae by degenerate PCR and TAIL-PCR. The open reading frame of appA consisted of 1,302 bp encoding 433 amino acid residues, including 27 residues of a putative signal peptide. The mature protein had a molecular mass of 45 kDa and a theoretical pI of 5.5. The amino acid sequence contained the conserved active site residues RHGXRXP and HDTN of typical histidine acid phosphatases, and showed the highest identity of 48.5% to PhyM from Pseudomonas syringae. The gene fragment encoding the mature phytase was expressed in Escherichia coli BL21 (DE3), and the purified recombinant phytase had a specific activity of 1,072$\pm$47 U/mg for phytate substrate. The optimum pH and temperature for the purified phytase were pH 5.0 and 50$^{\circ}C$, respectively. The $K_m$ value was 0.17 mM, with a $V_{max}$ of 1,714 $\mu$mol/min/mg. This is the first report of the identification and isolation of phytase from Pectobacterium.

• The Korean Journal of Pharmacology
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• v.22 no.2
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• pp.144-150
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• 1986

Glutathione peroxidase might play an important role in the protection of cellular structures against oxidative challange by hydrogen peroxide and several organic hydroperoxides. It is widely accepted that allicin is biological active component of garlic, and allicin is easily degraded to diallyl disulfide and other components. This study was attempted to elucidate the effect of diallyl disulfide on some biological activities. It was observed that the activity of serum transaminase and glutathione level in liver were not changed by the treatment of diallyl disulfide. The liver cytosolic glutathione peroxidase activity was significantly enhanced. Whereas, mitochondrial enzyme activity was slightly increased. In the presence of diallyl disulfide in vitro, $V_{max}$ value of glutathione peroxidase for hydrogen peroxide was increased. On the other hand, Km value was not changed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.3
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• pp.57-66
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• 2001

This paper resents a control approach for designing a fuzzy-PI controller for a synchronous generator excitation and SVC system A combination of thyristor-controlled reactors and fixed capacitors (TCR-FC) type SVC is recognized as having the must fiexible control and high speed response, which has been widely utilized in power systems, is considered and designed to improve the response of a synchronous generator, as well as controlling the system voltage A Fuzzy-PI controller for SVC system was proposed in this paper. The PI gain parameters of the proposed Fuzzy-PI controller which is a special type of PI ones are self-tuned by fuzzy inference technique. It is natural that the fuzzy inference technique should be barred on humans intuitions and empirical knowledge. Nonetheless, the conventional ones were not so. Therefore, In this paper, the fuzzy inference technique of PI gains using MMGM(Min Max Gravity Method) which is very similar to humans inference procedures, was presented and allied to the SVC system. The system dynamic responses are examined after applying all small disturbance condition.

• Journal of The Korea Institute of Healthcare Architecture
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• v.23 no.1
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• pp.15-24
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• 2017

Purpose: Korea is expected to enter an aged society in 2018 and then a super-aged society in early 2025. The country's aging is progressing faster than any other country in the world. However, the foundation of the elderly friendly industry is weak, and measures at the government level are urgently needed. Especially, housing problems of the elderly are one of the most urgent measures to be taken. Korea does not have the minimum residential area standard for the elderly, and the current general minimum residential area standard is based on the survey of the housing situation without scientific evidence. Therefore, both standards need to be revised as soon as possible based on scientific evidence. Methods: The minimum residential area standard has been calculated following Karl H. E. Kroemer's Min or Max design also being called as-single cut and dual cut theory- as the maximum population value and minimum population value theory of Ernest J. McCormick. Therefore there is a need for a formula made using a few key factors, such as corresponding dimension, practical dimension, clearance, spare dimension, integrated dimension. These elements can be defined and used as formulas to calculate minimum residential area standards. Results: Assuming the results of the spatial variability in this study showed that it is possible to raise the standard of living in a terms of sustainable minimum size for the young, old and all residents. Implications: The government should set a minimum residential area standard with scientific grounds and set up a policy improving the life of people who live in an needy residential environment.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.179.2-179.2
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• 2013

A large-area RF-driven ion source is being developed at Germany for the heating and current drive of ITER device. Negative hydrogen ion sources are major components of neutral beam injection (NBI) systems in future large-scale fusion experiments such as ITER and DEMO. The RF sources for the production of positive hydrogen ions have been successfully developed at IPP (Max-Planck-Institute for Plasma Physics), Garching, for the ASDEX-U and W7-AS neutral beam heating systems. Ion sources of the first NBI system (NBI-1) for the KSTAR tokamak have been developed successfully with a bucket plasma generator based on the filament arc discharge, which have contributed to achieve a good plasma performance such as 15 sec H-mode operation with an injection of 3.5 MW NB power. There is a development plan of RF ion source at the KAERI to extract the positive ions, which can be used for the second NBI system (NBI-2) of the KSTAR and to extract the negative ions for future fusion devices such as Fusion Neutron Source and Korea-DEMO. The development progresses of RF ion source at the KAERI are described in this presentation.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.242-243
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• 1998

This research was conducted to find the most effective and economical artificial propagation method of Lycoris squamigera among chipping, half-chipping, twin-scaling, coring, scooping and notching, in order to investigate the number of bulblets obtained from one bulb and the number of bulbs treated by a man in a day for artificial propagation. We got 42.2 bulblets from one bulb by twin-scaling, 23.2 bulblets by half-chipping, 18.2 bulblets by chipping, 14.3 bulblets by notching, 1 bulblet by coring and also 1 bulblet by scooping. Although we got the most bulblets by twin-scaling, it took the most time to treat the bulbs for artificial propagation (200 bulbs per day) and the bulblets formed were very small. But 400 bulbs were treated in a day by chipping and the bulblets formed were comparatively large. In addition, machines could be used for chipping, so chipping was considered to be the most effective and economical artificial propagation method.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.12 no.1
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• pp.25-30
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• 1976

In the area of the Far East Asia, cyclones are observed 157ea in winter season during the years(1966-1974). Some of them are most difficult to be forecasted due to the extreme irregulalities, have carried out synoptic analysis. The rapid development of cyclones can be attributed to the descending of cold air mass surrounding the axis of the Jet Stream due to the cyclonic rotation, and the lowering of the Jet axis. The Relationships between upper trough line and max. (or min) axis of upper air temperature on the 700mb contributes to the development of the cyclones.

• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.352-359
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• 2006

VoD 전송 방식을 설계할 때 가장 중요한 요소들에는 정해진 대역폭에서 사용자 대기시간 (Viewer's Waiting Time)과 클라이언트에서 요구하는 최대 버퍼 요구량(Max Client Buffer Requirement)을 줄이는 문제를 꼽을 수 있다. 점점 더 복잡해지는 VoD 전송 기술의 개발로 인해 사용자 대기시간과 최대 버퍼 요구량의 관점에서 성능 향상과 반비례하는 시스템 복잡도를 줄이는 문제 또한 VoD 전송 방식을 설계 시 고려 해야 할 중요 사항 중의 하나이다. 이 논문에서는 시스템 복잡도를 낮추면서 사용자 대기시간과 최대 버퍼 요구량의 성능을 동시에 향상시키기 위한 방법으로 기존의 VoD 전송 방식들 가운데 가장 간단한 모델과 최대 버퍼 요구량의 성능을 가장 향상시킨 모델의 결합으로 구현 가능한 Hybrid 방식을 제안하고 있다. 이 논문은 결과적으로 사용자 대기시간은 기존 Staircase Broadcasting방식과 Fast Broadcasting 방식과 비교했을 때 동일한 성능을 나타내고 있고 최대 버퍼 요구량은 유사성능을 나타냄을 알 수 있다. 이 논문에서 제안한 방식은 사용자 대기시간이 짧아야 하고 저장공간이 많이 요구되지 않으며 사용자의 요청이 갑자기 증가될 수 있는 hot 비디오에 적용이 가능하다. 또한 다양한 환경에 따라 Staggered Broadcasting 방식과 Staircase Broadcasting 방식의 채널 수를 적절히 조정함으로써 데이터 송수신 효율을 극대화 시킬 수 있다. 이 논문의 구성은 제시한 방법에 적용된 방식들과 비교대상이 되는 방식들에 대해 살펴보고 제시한 방식의 성능 모델을 이용한 실험을 통해 각종 VoD 전송 방식들과 비교 분석하는 과정으로 기술하였다.

• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1446-1454
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• 2021

Herein, we cloned and expressed an endo-β-1,4-glucanase gene (celA1805) from Bacillus subtilis B111 in Escherichia coli. The recombinant celA1805 contains a glycosyl hydrolase (GH) family 8 domain and shared 76.8% identity with endo-1,4-β-glucanase from Bacillus sp. KSM-330. Results showed that the optimal pH and temperature of celA1805 were 6.0 and 50℃, respectively, and it was stable at pH 3-9 and temperature ≤50℃. Metal ions slightly affected enzyme activity, but chemical agents generally inhibited enzyme activity. Moreover, celA1805 showed a wide substrate specificity to CMC, barley β-glucan, lichenin, chitosan, PASC and avicel. The K_m and V_max values of celA1805 were 1.78 mg/ml and 50.09 µmol/min/mg. When incubated with cellooligosaccharides ranging from cellotriose to cellopentose, celA1805 mainly hydrolyzed cellotetrose (G4) and cellopentose (G5) to cellose (G2) and cellotriose (G3), but hardly hydrolyzed cellotriose. The concentrations of reducing sugars saccharified by celA1805 from wheat straw, rape straw, rice straw, peanut straw, and corn straw were increased by 0.21, 0.51, 0.26, 0.36, and 0.66 mg/ml, respectively. The results obtained in this study suggest potential applications of celA1805 in biomass saccharification.