• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.645-649
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• 1998

A glycolipid type of biosurfactants was obtained from a strain which had been isolated from soil. The cell was identified as Pseudomonas aeruginosa from taxonomic characteristics and was designated as YPJ80. Thin layer chromatography and deoxyhexose detection tests were done to verify the type of biosurfactant. Critical micelle concentration (CMC) of the surfactant was observed to be 50 ppm and the minimum surface tension was 30.1 mN/m. As an emulsifier, YPJ80 biosurfactant was superior to emulsan in the emulsification of crude Arabian light oil.

• Microbiology and Biotechnology Letters
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• v.18 no.6
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• pp.624-632
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• 1990

Strain 88-GT-161 producing new phthalic acid derivative and basic macrolide antibiotics was identified as being S. melanosporofuciens based on numerical taxonomic data. However, 4 unit characters among 139 units were clearly different from the common properties of 6 strains belonging to cluster No. 32 represented by the name of S. violaceoniger or S. violaceusniger, leading us to designate as a variety of S. melunosporofaciens. This paper describes the taxonomic characteristics of the strain. Isolation and chemical structures, including biological activities of the active compounds produced by this strain will be presented elsewhere.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.4
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• pp.173-178
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• 2008

Electro-hydraulic brake system has many advantages. It provides improved braking performance and stability functions. It also removes complex mechanical parts for freedom of design, improves maintenance requirements and reduces unit weight. However, the EHB system should be dependable and have back-up redundancy in case of a failure. In this paper, the model-based fault diagnosis system is developed to monitor the brake status using the analytical redundancy method. The performance of the model-based fault diagnosis system is verified in real-time simulation. It demonstrates the effectiveness of the proposed system in various faulty cases.

• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.343-348
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• 1994

Enterobacter sp. producing -$\beta$-galactosidase with high transgalactosylation activity was isolated from dairy wastewater. The isolate had common biochemical features to E. aerogenes and E. cloacae. Enzyme production increased as the cell mass increased with optimum enzyme activity of 0.21 Unit/mg-protein (o-nitro-phenyl-$\beta$ -D-galactoside (ONPG) as substrate) until 8 hr of culture. Whole cells permeabilized by toluene were used to produce galacto-oligosaccharide. Optimum toluene concentration, temperature and pH for -$\beta$-galactosidase activity of permeabilized whole cells were 10% (v/v), $50^{\circ}C$ and 6.0, respectively. A maximum of 38% (w/w) of galacto-oligosaccharide was obtained with lactose concentration of 20% (w/w) at $40^\{\circ}C$ and pH 6.0.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.187-196
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• 1995

In order to produce fuctional chitooligosaccharides, a strain excreting mainly endo-type chitinase suitable for chitooligosaccharides production was newly screened and identified as Aspergillus fumigatus JC-19. The chitinase excretion was repressed in nutrient rich medium but stimulated by colloidal chitin indicating that the chitinase is inducible type enzyme. Maximum secretion of the enzyme was observed at pH 7.0 and 37$\circ$C . The growth and chitinase production patterns of Aspergillus fumigatus JC-19 showed that the cell growth reached maximum after 4-5 days with final chitinase concentration of 0.46 unit per ml. Excreted chitinase was purified by ammonium sulfate precipitation, colloidal chitin adsorption, anion exchange chromatography, and gel filtration, respectively, and measured M.W of 50 KDa. The enzyme reaction carried out both by crude and purified chitinase showed that the purified chitinase accumulated more chitooligosaccharides of 1-6 degree of polymerization than that of crude chitinase.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.565-572
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• 1995

The aim of the present research program was to develop a strain of actinomycetes producing extracellular cathepsin B inhibitor. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying various physical and chemical pretreatments. An economical and effective method was developed for the screening of strains producing low molecular weight cathepsin B inhibitor, and consequently a strain (SMF28) among over 700 isolates was selected. Chemotaxonomic and numerical identification were carried out for the isolate. Fifty taxonomic unit characters were tested and the data were analyzed numerically using TAXON program. The isolate was identified as a strain of Streptomyces chromofuscus.

• KIEAE Journal
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• v.4 no.3
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• pp.187-194
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• 2004

In many other buildings, hospital is very important because of its function and purpose. A proper building service systems including heating, cooling, ventilation and plumbing systems is required in hospial. Besides, a special systems like medical gas, vacuum cleaning systems are required to prevent contamination as well as cure a patient in hospital. Ventilation is very important method to keep the indoor pressure and clean class. There are some specific rooms to consider clean class and indoor pressure in the general hospital. In this article, specific rooms were set to operating room, laboratory, ICU, isolation unit, and sterilizer room. In this case study, design factors of ventilation system, including air changes of OA and TA, indoor pressure, clean class, filter, and material of system, of specific rooms in hospital were proposed through a literature research and a design examples review.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.1
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• pp.3-15
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• 1996

An approximation algorithm is presented for cyclic queueing networks with finite buffers. The algorithm decomposes the queueing network into individual queues with revised arrival and service process and revised queue capacity. Then, each queue is analyzed in isolation. The service process reflects the additional delay a unit might undergo due to blocking and the arrival process is described by a 2-phases Coxian ($C_2$) distribution. The individual queues are modelled as $C_2/C_2$/1/B queues. The parameters of the individual queues are computed approximately using an iterative scheme. The population constraint of the closed network is taken into account by ensuring that the sum of the average queue lengths of the individual queues is equal to the number of customers of the network. Extensive numerical experiments show that this method provides a fairly good estimation of the throughput.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.623-626
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• 2003

Nematophin and its analog incorporating tryptamine unit have been isolated and characterized from strain XRPC of a symbiotic bacterium Xenorhabdus nematophilus, which was newly isolated from Korean entomopathogenic nematodes. The stereoselective synthesis of these compounds was accomplished, and the relative configurations were determined. Nematophin exhibited potent antibacterial activities over several strains of methicillin-resistant S. aureus (MRSA) comparable to those of vancomycin.

• Korean Journal of Pharmacognosy
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• v.19 no.1
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• pp.28-33
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• 1988

To identify biologically active enzymatic components of the higher fungi in Korea, the dried carpophores of Cryptoderma citrinum was smashed with cool distilled water, extracted, salted out and the precipitate was purified by dialysing with visking tube and dissolved with pH 7.8 ammonia aqua. The fraction of the filtrate was lyophilized to obtain as light brown powder and then cellulase activity was determined. Cellulolytic potency of Cryptoderma citrinum was 750 unit/g. The optimum condition for the enzymatic reaction was pH 4.5 and $40^{\circ}$. The enzyme activity was activated in the presence of $Ca^{2+}$, $Fe^{2+}$ and $Co^{2+}$.