• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.270-278
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• 1992

Two of the Hard White Winter (HWW) wheats had higher farina yield than mixed Hard Red Winter (HRW) wheat. Optimum steaming time for HRW farina spaghetti was 3min under 86-98$^{\circ}C$. Optimum cooking time decreased after steam treatment. Steam treated spaghetti showed much higher strength of dried spaghetti, lower cooking loss, and cooked weight, less stickiness, and total organic matters (TOM) value than in treated spaghetti after cooking. The rooking qualities except stickiness were significantly different between treated and untreated steam. The quality of hard wheat farina spaghetti was more affected than that of durum spaghetti after steam treatment. HWW farina spaghetti im-roved all the qualities of steam treated and untreated spaghetti than those of HRW farina spaghetti except stickiness. From the observations of scanning electron microscope (SEM), maybe two general principles of steaming can be explained by : i) forming hydrophobic protein film on surface of pasta, ii) higher retrogradation of starch, which cause less swelling of starch.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1415-1425
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• 2017

Typhoons are accompanied by strong wind and heavy rains. It causes casualties and property damage on the Korean peninsula every year. The effect of typhoon to daily precipitation should be quantified to prevent the damage of typhoon. Daily precipitation, maximum wind speed and, mean wind speed data was collected from 60 weather stations between 1976 and 2016. The parameters of the generalized extreme value distribution were estimated through the maximum likelihood estimation and the L-moment estimation. The impact of a typhoon can be obtained through a comparison of return levels between the whole data and typhoon excluded data. We conclude that the eastern and southern coastline are exposed to the risk of heavy rainfall which is caused by typhoon.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.858-863
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• 2002

An antimicrobial compound was isolated from the MeOH extract of Catalpa ovata G.$D_{ON}$ fruits, and its structure was Identified as 4,9-dihydroxy-2,2-dimethyl-3,4-Uihydronaphtho[2,3-b]pyran-5,10-dione (HMNP). The antimicrobial activity of the Un was determined by measuring the dose-response inhibiton of microbial growth in liquid cultures and then compared with that of lapachol, a well known antimicrobial 1,4-naphthoquinone. The antimicrobial activity of the HMNP was more effective than that of lapachol over a wide range of test organisms. Gram-positive bacteria, yeast, and fungi ($IC_{50}$ $20-75\muM$) were found to be more sensitive to the HMNP than Cram-negative bacteria ($IC_{50}$ > $100\muM$). The HMNP also inhibited germination of spores of many fungi. The morphological defurmation of the fungal spores was induced by the treatment of HMNP, as illustrated by Scanning Electron Microscopy (SEM).

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.367-372
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• 2005

Antimicrobial effects of the extracts from Castanea crenata leaf were investigated. The antimicrobial effects of methanol extract (8 mg, 20 mg) of 0.2 g and 0.5 g. eq. of Castanea crenata leaf was stronger than that of 0.65 mg of benzoic acid against Gram(+) bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus, Leuconostoc mesenteroides and Bacillus subtilig and Gram(-) bacteria such as Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. Growth inhibition of various microorganisms was observed in Castanea crenata leaf, therefor the Castanea crenata leaf were solvent fractionated. The ethyl acetate-soluble acidic and phenolic fraction were showed remarkable antimicrobial activity against microorganisms tested. The acidic fraction was purified with silica gel adsorption column chromatography, Sephadex LH-20 column chromatography and HPLC, subsequantly. The antimicrobial active substance isolated from the acid fraction of Castanea crenata leaf was characterized as stigmast-5-en-3-ol($\beta$-sitosterol) by MS and NMR analysis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.5
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• pp.373-379
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• 2019

If two signals with the same single-tone frequency and differing phases impinge simultaneously on an antenna at slightly differing angles, then a large error in the angle estimation might occur if the phase difference is either $0^{\circ}$ or $180^{\circ}$. This phenomenon might arise with an airborne fire-control radar, which has a relatively small bandwidth, for a low-flying target over the sea or terrain surface. In this paper, we show that the $Cram{\acute{e}}r$-Rao lower bound for such a target can be significantly lowered with the use of two frequencies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.169-172
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• 2019

Frequency-modulated continuous wave(FMCW) radars with array antennas are widely used because of their light weight and relatively high resolution. A usual approach for the joint range and angle estimation of a target using an array FMCW radar is to create a range-angle matrix with the deramped received signal, and subsequently apply two-dimensional(2D) frequency estimation methods such as 2D fast Fourier transform on the range-angle matrix. However, such frequency estimation approaches cause bias errors since the frequencies in the range-angle matrix are not independent. Therefore, we propose a new maximum likelihood-based algorithm for joint range and angle estimation of targets using array FMCW radar, and demonstrate that the proposed algorithm achieves the Cram?r-Rao bounds, both for range as well as angle estimation.

• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.180-183
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• 2020

Purpose: To describe pediatric coronavirus disease 2019 (COVID-19) cases after the reopening of schools in the Republic of Korea and their transmission routes. Methods: All case report forms and epidemiologic investigation forms for children aged 3-18 years reported as COVID-19 cases to the National Notifiable Disease Surveillance System from May 1 to July 12, 2020, were reviewed. Results: After the schools were reopened in May 2020, a total of 127 pediatric COVID-19 cases were confirmed until July 12. Of these, 59 children (46%) were exposed to severe acute respiratory syndrome coronavirus 2 through family and relatives, followed by 18 children (14%) through cram schools or private lessons, 8 children (6%) through multi-use facilities, and 3 children (2%) through school. Conclusions: The present data do not suggest an increased risk of COVID-19 transmission in the context of stringent school-based infection prevention measures introduced across the country.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.545-549
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• 2001

To develop a natural antibacterial agent for fish bacterial diseases, antibacterial activity, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and bactericidal effect of cinnamon bark extract were examined against fish pathogenic bacteria. The antimicrobial effect of the extract to the fish diet was also estimated, Cinnamon bark extract showed the broad spectrum of antibacterial activity against fish pathogenic bacteria, especially, it had strong activity against Streptococcus iniae, Edwardsiella tarda and Listonella anguillarum. Its MIC was $75.8\sim189.6{\mu}g/mL$ against Cram positive bacteria, and $75.8\sim113.8{\mu}g/mL$ against Gram negative bacteria in liquid medium, It was found to show stronger bactericidal action against Gram negative bacteria than Cram positive bacteria. According to increasing concentrations of the extract, it resulted in a proportional reduction of viable cell counts of both S. iniae and L. anguillarum. The former was not detected by addition of $189.6{\mu}g/mL$ after 12 hours incubation and the latter by addition of $151.6{\mu}g/mL$ after 24 hours incubation, respectively. It was reasonable that fish diet was soaked in cinnamon bark extract for ten minutes. The relationship formula between the weight of fish diet and the extract absorbed to fish diet was Y=7.2726X+4.5083 ($R^2=0.9998$). The fish diet soaked in the extract inhibited the growth of all strains used in this study. Its antibacterial activity was stable at the range from $10^{\circ}C\;to\;35^{\circ}C$ during the storage period of 28 days. When the diet soaked in the extract was incubated in liquid medium at $35^{\circ}C$, it inhibited the growth of microorganisms inhabited in the diet.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.743-748
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• 2005

Histamine can be produced at early spoilage stage through decarboxylation of histidine in red-flesh fish by Proteus morganii, Hafnia alvei or Klebsiella pneumoniae. Allergic food poisoning is resulted from the histamine produced when the freshness of Mackerel degrades. Conversely it has been reported that there are bacteria which decompose histamine at the later stage. We isolated histamine decomposers from salted mackerel and studied the characteristics to help establish hygienic measure to prevent outbreak of salted mackerel food poisoning. All the samples were purchased through local supermarket. Histamine decomposers were isolated using restriction medium using histamine 10 species were selected. Identification of these isolates were carried out by the comparison of 16S rDNA partial sequence; as a result, we identified Pseudomonas putida strain RA2 and Halomonas marina, Uncultured Arctic sea ice bacterium clone ARKXV1/2-136, Halomonas venusta, Psychrobacter sp. HS5323, Pseudomonas putida KT2440, Rhodococcus erythropolis, Klebsiella terrigena (Raoultella terrigena), Alteromonadaceae bacterium T1, Shewanella massilia with homology of $100\%,{\;}100\%,{\;}99\%,{\;}99\%,{\;}99\%,{\;}99\%,{\;}100\%,{\;}95\%,{\;}99\%,{\;}and{\;}100\%$respectively. Turbidometry determination method and enzymic method were employed to determine the ability of histamine decomposition. Among those species Shewanella massilia showed the highest in ability of histamine decomposition. From these results we confirmed various histamine decomposer were present in salted mackerel product in the market.

• Journal of Nutrition and Health
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• v.45 no.6
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• pp.588-599
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• 2012

There is a limitation to estimate vitamin $B_{12}$ intake due to the lack of data on vitamin $B_{12}$ content of Korean commercial foods. In this study, vitamin $B_{12}$ content was determined in favorite Korean restaurant foods, convenient or instant foods, fast foods and bakery products through a modified microbioassay using Lactobacillus delbrueckii ATCC 7830. Bulgogi and seafood & green pepper griddle had high vitamin $B_{12}$ content, 3.50 and $2.96{\mu}g$/100 g, respectively. Pork suyook, pork griddle and pollack griddle had 0.48, 0.31 and $0.32{\mu}g$/100 g of vitamin $B_{12}$, respectively. In stew, soft-tofu stew with seafood and doenjang stew with seafood had relatively high vitamin $B_{12}$ content, 1.93 and $1.44{\mu}g$/100 g, respectively. Bibimbap and 4 different types of rice porridge, beef & mushroom, chicken & ginseng, seafood or abalone, had 0.36, 0.08, 0.09, 1.64 and $0.13{\mu}g$/100 g of vitamin $B_{12}$, respectively. One serving of haejanggguk, yookejang, chuotang and galbitang had 5.97, 2.04, 2.63 and $1.91{\mu}g$ of vitamin $B_{12}$, respectively. One serving of samgetang and sulongtang had $2.89{\mu}g$ and $6.64{\mu}g$ of vitamin $B_{12}$. In noodles, one serving of cram noodle soup, bibim-nangmyeon, and mul-nangmyeon had 18.8, 1.21 and $0.38{\mu}g$ of vitamin $B_{12}$, respectively. One regular gimbap and one triangle gimbap contained 1.09-2.53 and $0.54-1.11{\mu}g$ of vitamin $B_{12}$, respectively. One cheese-burger, chicken-burger and bulgogi-burger had 0.76, 0.62 and $0.54{\mu}g$ of vitamin $B_{12}$, respectively. A plain bagel and a waffle contained 0.13 and $0.17{\mu}g$/100 g of vitamin $B_{12}$, respectively. Ready-made tomato sauce or cream sauce for spaghetti in a retort pouch contained only a trace of vitamin $B_{12}$. In conclusion, these results should contribute to improving the present food vitamin $B_{12}$ content database, most of which were cited from foreign data, thereby it could be helpful to estimate the vitamin $B_{12}$ intake of Koreans more accurately than before. It will also provide new information for dietary education related to vitamin $B_{12}$ and health.