• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.157-160
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• 2008

색온도 및 광색 가변형 100W RGBY LED 투광기를 개발하기 위하여, 투광기의 광학 및 방열기구를 설계하였다. 또한 100W LED 광원모듈을 구동하기 위한 구동회로와 색온도 및 광색 가변을 위한 제어회로를 개발하였다. 이와 같은 설계결과를 적용하여 100W RGBY 투광기의 시제품을 제작하였고, 시제품의 광학적 성능은 협각 $20^{\circ}$, 중각 $50^{\circ}$, 광각 $75^{\circ}$이상을 만족시켰다. 또한 색온도의 변화는 CIE 1931 색좌표에서 흑체궤적과 일치하여 $2,000K{\sim}10,000K$까지 변화하도록 R,G,B,Y LED의 Duty Ratio를 설정하였다. 또한 방열 특성은 100W 구동시 녹색 LED의 온도는 $37{\sim}41.3^{\circ}C$, heatsink의 온도는 $34{\sim}35^{\circ}C$에서 동작되도록 하였다.

• Genomics & Informatics
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• v.18 no.4
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• pp.44.1-44.7
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• 2020

The severity of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), greatly varies from patient to patient. In the present study, we explored and compared mutation profiles of SARS-CoV-2 isolated from mildly affected and severely affected COVID-19 patients in order to explore any relationship between mutation profile and disease severity. Genomic sequences of SARS-CoV-2 were downloaded from Global Initiative on Sharing Avian Influenza Data (GISAID) database. With the help of Genome Detective Coronavirus Typing Tool, genomic sequences were aligned with the Wuhan seafood market pneumonia virus reference sequence and all the mutations were identified. Distribution of mutant variants was then compared between mildly and severely affected groups. Among the numerous mutations detected, 14408C>T and 23403A>G mutations resulting in RNA-dependent RNA polymerase (RdRp) P323L and spike protein D614G mutations, respectively, were found predominantly in severely affected group (>82%) compared with mildly affected group (<46%, p < 0.001). The 241C>T mutation in the non-coding region of the genome was also found predominantly in severely affected group (p < 0.001). The 3037C>T, a silent mutation, also appeared in relatively high frequency in severely affected group compared with mildly affected group, but the difference was not statistically significant (p = 0.06). We concluded that spike protein D614G and RdRp P323L mutations in SARS-CoV-2 are associated with severity of COVID-19. Further studies will be required to explore whether these mutations have any impact on the severity of disease.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1293_1294
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• 2009

The sintering and high frequency electro-magnetic properties of Ba-hexagonal ferrite were investigated. All samples of the Ba-hexagonal ferrite were prepared by the conventional mixed oxide method and sintered at $1150^{\circ}C$~$1400^{\circ}C$. From the X-ray diffraction patterns of sintered Ba-hexagonal ferrite, the $Ba_3Co_2Fe_{24}O_{41}$ phase was represented as main phase in the almost sintering conditions. The bulk densities with sintering temperature and decreased at $1400^{\circ}C$. The permittivity ($\varepsilon$') and loss tangent of permittivity ($\varepsilon$"/$\varepsilon$') of $Ba_3Co_2Fe_{24}O_{41}$ ceramics increased and decreased with sintering temperature, respectively. The permeability of $Ba_3Co_2Fe_{24}O_{41}$ ceramics decreased with sinteirng temperature. The loss tangent of permeability was not changed compared each other with sintering temperature. The bulk density of $Ba_3Co_2Fe_{24}O_{41}$ ceramics sintered at $1300^{\circ}C$ was 4.79 g/$cm^3$. The permittivity, loss tangent of permittivity and permeability, loss tangent of permeability were 19.896, 0.1718 and 14.218, 0.2046 at 210 MHz, respectively.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.435-438
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• 2000

Crude oil-degrading microorganisms, Acinetobacter sp. A132, Pseudomonas aeruginosa F722, and Acinetobacter calcoaceticus OM1 were isolated from soil and sea. The optimal temperature of strain A132 and strain F722 on growth isolated from soil was $35^{\circ}C$ both, and also their growth were optimized at pH 8 and 9, respectively. The growth of the strains, A132 and F722, showed that crude oil of 2% (w/v) in culture broth in which crude oil was used as carbon and energy sources appeared to be an optimum. Optimal culture conditions of strain OM1 were different from those of the soil microorganisms except for temperature. The growth of strain OM1 was optimized at pH 7 and crude oil of 3.0% (w/v). The degradability to crude oil by strain A132 showed maximum $5.49g/\;l\;{\cdot}\;day$ under the conditions of $25^{\circ}C$, NaCl of 1.0% (w/v), and crude oil of 2.0% (w/v). The highest degradability of strain F722 to crude oil was $1.19g/\;l\;{\cdot}\;day$ under the culture conditions at $35^{\circ}C$, NaCl 1.0% (w/v), and crude oil of 2.0% (w/v). The degradation characteristics of kerosene $(nC_9-nC_{20})$ and diesel $(nC_9-nC_{28})$ by strain OM1, and F722 were analyzed by gas chromatography. Strain OM1 degraded more than 95% of kerosene and 75% of diesel for 7 days cultivation. Strain F722 showed degradation of more than 80% to kerosene in 10 days.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.92-100
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• 1996

For the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(P(3HB-co-3HV)) from butyric acid and valeric acid, 10 strains of bacteria capable of producing P(3HB-co-3HV) were isolated from soil. Among them, the strain HJ-067 showed the best ability of producing P(3HB-co-3HV), and was indentified as a Azotobacter sp. For the production of P(3HB-co-3HV), the optimum concentrations of butyric and valeric acid were 3.0g/l, respectively. The most effective nitrogen source was $(NH_4)_{2}SO_4$ at an optimum concentration of 0.75g/l, which was equivalent to 21.36 in C/N ratio. Deficiency of the cationic metal ions ($Zn^{2+},\;Co^{2+},\;Mn^{2+}$) in the proguction medium had stimulating effect on P(3HB-co-3HV) accumulation, especially in the manganese. deficient medium. The optimum temperature for P(3HB-co-3HV) production was 27$^{\circ}C$ and the optimum initial pH was 7.0. Under the optimum conditions, 1.82g/l of P(3HB-co-3HV) and 3.00g/l of dry biomass were produced after 36 hour cultivation, and the P(3HB-co-3HV) yield and HV% were 60.60% (w/w), 15.92%, respectively.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.319-323
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• 2008

Mutant rice cv. Goami2 (G2) and Baegjinjoo (BJJ) derived from a high-quality japonica rice cv. Ilpumbyeo (IP) were extruded under different feed moisture (20 and 30%) and barrel temperature (90, 110, and $130^{\circ}C$). Increasing feed moisture at fixed barrel temperature increased extrudate density (ED) in IP and BJJ. Whereas, G2 showed a varied ED depending on extrusion conditions; increasing barrel temperature decreased the ED of G2 extrudate with low feed moisture, but increased with high moisture. Results indicated a positive barrcl temperature effect on volume expansion in IP and G2, but a negative effect on 811, probably due to shrinkage of expanded products containing low-amylose contents. A significant increase of water absorption was found in G2 and BJJ extruded flour, while an increase of water solubility in those from IP. Non-digestible carbohydrates measured by total dietary fiber (TDF) indicated that extrusion increased slightly TDF in IP and BJJ extrudates, but decreased in G2 products, which might be variety-dependent.

• Journal of Animal Environmental Science
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• v.19 no.1
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• pp.55-62
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• 2013

Teff grass is a warm season C4 annual grass that is used for dry hay, silage and haylage. We have developed a high-frequency plant regeneration system for teff grass via callus culture using mature seeds. It was revealed that mature seeds cultured on MS medium supplemented with 2 mg/l 2,4-D, 0.5 g/L proline, 0.5 g/L casamino acid and 3 g/L Gelrite under light condition produced the highest percentage of callus formation (91.9%). Addition of cytokinins (BA) at 0.0~0.5 mg/L to media containing 2 mg/l 2,4-D enhanced callus growth. The most suitable medium for plant regeneration from dehydrated calli was MS agar medium supplemented with 0.1 mg/l NAA, 1 mg/l BA, 0.5 g/L proline, 0.5 g/L casamino acid 3 g/L Gelrite which induced the highest percentage of calli forming shoots (47.0%). The shoots were rooted at the highest rate (100%) when transferred onto 1/2 MS medium and acclimated in greenhouse conditions.

• Food Science and Preservation
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• v.22 no.1
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• pp.36-43
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• 2015

The edible crab is among the rich resources that can be used as materials for food products, but living crabs and crabs marinated in soy sauce are the only widely utilized materials for food products. For seafood development, research is needed to promote the use of crabs in various products. In this study, the quality changes of fried rice prepared with crab meat, crab emulsion sauce and crab cooker effluent were investigated. The pH and acidity values did not show any significant difference at $-20^{\circ}C$. The acidity of the fried rice continuously increased during storage at 4 and $25^{\circ}C$. The VBN and TBA values of the fried rice stored at 4 and $25^{\circ}C$ were significantly higher than those of the fried rice stored at $-20^{\circ}C$ during the storage period. The viable cell count of the fried rice stored at $-20^{\circ}C$ changed little during the storage period while that of the fried rice stored at 4 and $25^{\circ}C$ rapidly increased over 2 weeks. For the fried rice stored at $-20^{\circ}C$, the overall quality did not show significant differences during the storage period. In conclusion, the best storage temperature for both quality and safety was found to be $-20^{\circ}C$. At such storage temperature, the quality of the stored instant rice using crab meat did not change, and through research the expanding possibilities of using crab materials were confirmed.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.246-259
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• 2014

This study was carried out to investigated the quality characteristics of kimchi, made by adding blue crab. Kimchi is made into a fermented vegetable food by adding red pepper powder, garlic, ginger and fermented salted fish to the salted cabbage or radish. Chitin/chitosan, found in the shell of crab is the biopolymer. Chitin possesses many beneficially biological properties. Salt consumption impacts on human health problems such as hypertension and cardiovascular disease. In this study, we hypothesized that kimchi added with raw blue crab would reduce excessive salt consumption and increase protein supplementation. We analyzed lactic acid bacteria level, pH, acidity, salinity and free amino acid of kimchi added with blue crab during 1, 15 and 30 days storage period at $5^{\circ}C$. Lactic acid bacteria, pH, salinity increased significantly in kimchi added with blue crab compared to the control. Accordingly, this result suggested that kimchi should be manufactured by adding raw fish rather than fermented salted fish.

• Genomics & Informatics
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• v.6 no.3
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• pp.110-116
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• 2008

Blood pressure refers to the force exerted by circulating blood on the walls of blood vessels, and chronical elevation of blood pressure is known as hypertension. Although hypertension is affected by genetic and environmental factors, the genetic background of hypertension is not fully understood. One of the candidate genetic factors, Prostaglandin-endoperoxide synthase 2 (PTGS2), is a membrane-bound enzyme, catalyzing the conversion of arachidonic acid to prostaglandin, and recently SNPs of PTGS2 gene was associated with hypertension in Japanese population. Therefore the association of PTGS2 polymorphisms was investigated with blood pressure in healthy Korean subjects, 470 unrelated individuals randomly selected from Ansung and Ansan cohorts. The 25 SNPs of PTGS2 gene were identified by the sequencing analysis of 24 Korean samples. Among identified polymorphisms, three SNPs (rs689466, -1329A>G; rs5275, +6365T>C; rs4648308, +8806G> A) were selected for further association analysis, and rs689466 located in promoter region was associated with blood pressure as well as triglyceride level in the blood. By in silico analysis, rs689466 locates in v-Myb transcription factor binding site, and the v-Myb site disappears when the SNP is changed from A to G nucleotide. Individuals with A/G and G/G genotype in rs689466 have higher blood pressure than those with A/A genotype, and the regression p-value is 0.008 for systolic and 0.004 for diastolic blood pressure. In summary, the PTGS2 polymorphism (rs689466) is associated with blood pressure in Asian populations based on this and Japanese studies, shedding light on it as a genetic risk marker of hypertension.