• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.197-202
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• 2008

With the growth of electrical power needs, demand of the knife-type switches in the distribution boards is increasing. We have developed a knife-type switch which is not currently produced in Korea. The switch was desinged and a comprehensive tooling for it was also accomplished. A total of two sets of injection molds and three sets of press dies were designed and manufactured. The parts for knife switches were produced using the tools. Finally, the parts were assembled together and the switch is now under the test phase.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2001.05b
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• pp.51-53
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• 2001

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.58-59
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• 1990

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.193-196
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• 1997

This paper proposes a new medical information management system to be used or small to medium sized clinics and hospitals. The system is designed to process, analyze and manage each patient's clinical record using database technique. The structure of the database was determined and implemented through careful and rigorous study of medical practices in Korea and, therefore, reflects the needs of information management in Korean medical community. Furthermore, a sophisticated inference engine that can deduce possible disease from the result of medical examination is added to the system to provide doctors with a guideline in medical diagnoses.

• Proceedings of the Korean Magnestics Society Conference
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• 2011.12a
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• pp.183-183
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• 2011

• 한국전산유체공학회:학술대회논문집
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• 2008.08a
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• pp.43.5-44
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• 2008

• Steel and Composite Structures
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• v.43 no.5
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• pp.639-660
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• 2022

The bending and buckling behaviours of FG-GRNC laminated sandwich plates are investigated by using novel five-variables quasi 3D higher order shear deformation plate theory by considering the modified continuum nonlocal strain gradient theory. To calculate the effective Young's modulus of the GRNC sandwich plate along the thickness direction, and Poisson's ratio and mass density, the modified Halpin-Tsai model and the rule of the mixture are employed. Based on a new field of displacement, governing equilibrium equations of the GRNC sandwich plate are solved using a developed approach of Galerkin method. A detailed parametric analysis is carried out to highlight the influences of length scale and material scale parameters, GPLs distribution pattern, the weight fraction of GPLs, geometry and size of GPLs, the geometry of the sandwich plate and the total number of layers on the stresses, deformation and critical buckling loads. Some details are studied exclusively for the first time, such as stresses and the nonlocality effect.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1586-1592
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• 2016

Klebsiella pneumoniae is a gram-negative, non-motile, rod-shaped, and encapsulated bacterium in the normal flora of the intestines, mouth, skin, and food, and has decarboxylation activity, which results in generation of diamines (cadaverine, agmatine, and putrescine). However, there is no specific information on the exact mechanism of decarboxylation in K. pnuemoniae. Specifically lysine decarboxylases that generate cadaverine with a wide range of applications has not been shown. Therefore, we performed a functional study of lysine decarboxylases. Enzymatic characteristics such as optimal pH, temperature, and substrates were examined by overexpressing and purifying CadA and LdcC. CadA and LdcC from K. pneumoniae had a preference for L-lysine, and an optimal reaction temperature of 37℃ and an optimal pH of 7. Although the activity of purified CadA from K. pneumoniae was lower than that of CadA from E. coli, the activity of K. pneumoniae CadA in whole cell bioconversion was comparable to that of E. coli CadA, resulting in 90% lysine conversion to cadaverine with pyridoxal 5'-phosphate L-lysine.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.382-391
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• 2019

Many poultry eggs are discarded worldwide because of infection (i.e., avian flu) or presence of high levels of pesticides. The possibility of adopting egg yolk as a source material to produce polyhydroxyalkanoate (PHA) biopolymer was examined in this study. Cupriavidus necator Re2133/pCB81 was used for the production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) or poly(3HHx), a polymer that would normally require long-chain fatty acids as carbon feedstocks for the incorporation of 3HHx monomers. The optimal medium contained 5% egg yolk oil and ammonium nitrate as a nitrogen source, with a carbon/nitrogen (C/N) ratio of 20. Time course monitoring using the optimized medium was conducted for 5 days. Biomass production was 13.1 g/l, with 43.7% co-polymer content. Comparison with other studies using plant oils and the current study using egg yolk oil revealed similar polymer yields. Thus, discarded egg yolks could be a potential source of PHA.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.115-122
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• 2021

Phenol-soluble modulins (PSMs) are responsible for regulating biofilm formation, persister cell formation, pmtR expression, host cell lysis, and anti-bacterial effects. To determine the effect of psm deletion on methicillin-resistant Staphylococcus aureus, we investigated psm deletion mutants including Δpsmα, Δpsmβ, and Δpsmαβ. These mutants exhibited increased β-lactam antibiotic resistance to ampicillin and oxacillin that was shown to be caused by increased N-acetylmannosamine kinase (nanK) mRNA expression, which regulates persister cell formation, leading to changes in the pattern of phospholipid fatty acids resulting in increased anteiso-C15:0, and increased membrane hydrophobicity with the deletion of PSMs. When synthetic PSMs were applied to Δpsmα and Δpsmβ mutants, treatment of Δpsmα with PSMα1-4 and Δpsmβ with PSMβ1-2 restored the sensitivity to oxacillin and slightly reduced the biofilm formation. Addition of a single fragment showed that α1, α2, α3, and β2 had an inhibiting effect on biofilms in Δpsmα; however, β1 showed an enhancing effect on biofilms in Δpsmβ. This study demonstrates a possible reason for the increased antibiotic resistance in psm mutants and the effect of PSMs on biofilm formation.