• The Bulletin of The Korean Astronomical Society
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• 제40권2호
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• pp.54.2-54.2
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• 2015

Within 100 pc of the Galactic Centre the tidal field is extremely strong. We investigate the survival of star clusters of different masses in strong tidal fields. We show that dense low-mass clusters are destroyed by strong tidal fields as the tidal fields add energy to the cluster. Only massive clusters (like the Arches) can survive for more than 1-2 Myr in strong tidal fields. Therefore, in Galactic Centre environments only massive young clusters should ever be observed.

• The Bulletin of The Korean Astronomical Society
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• 제40권1호
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• pp.54.1-54.1
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• 2015

We report results of investigation of amplitude calibration for very long baseline interferometry (VLBI) observations with Korean VLBI Network (KVN). Amplitude correction factors are estimated based on comparison of KVN observations at 22 GHz correlated by Daejeon hardware correlator and DiFX software correlator in Korea Astronomy and Space Science Institue (KASI) with Very Long Baseline Array (VLBA) observations at 22 GHz by DiFX software correlator in National Radio Astronomy Observatory (NRAO). We used the observations for compact radio sources, 3C 454.3 and NRAO 512 which are almost unresolved for baselines in a range of 350-477 km. VLBA visibility data of the sources observed with similar baselines as KVN are selected, fringe-fitted, calibrated, and compared in their amplitudes. We found that visibility amplitudes of KVN observations should be corrected by factors of 1.14 and 1.40 when correlated by DiFX and Daejeon correlators, respectively. These correction factors are attributed to the combination of two steps of 2-bit quantization in KVN observing systems and characteristics of Daejeon correlator.

• Korean journal of food and cookery science
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• 제23권2호통권98호
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• pp.245-251
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• 2007

The purpose of this study was to examine how potato glycoalkaloid(PGA) contents changed as storing temperatures and periods changed for potatoes(Superior) cultivated in Korea. Some potatoes were stored at $5^{\circ}$C for 80 days, and others were stored at $20^{\circ}$C for 40 days. PGA contents were measured every 20 days for the potatoes stored at $5^{\circ}$C and 10 days for those stored at $20^{\circ}$C. The results can be summarized as follows. The amounts of a-chaconine and a-solanine measured on the first day of storage were 54.22 mg/100 g and 26.57 mg/100 g, respectively. Thus, the a-chaconine content was almost twice as much as the a-solanine content. The sprouts of potatoes stored at $5^{\circ}$C grew by 0.4 cm in 20 days, 1 cm in 40 days, 1.8 cm in 60 days, and 5.2 cm in 80 days. Furthermore, the PGA content increased by 3.5% in 20 days, 11.6% in 40 days, 23.4% in 60 days, and 41.4% in 80 days, compared to the PGA content on the first day. The sprouts of potatoes stored at 20 grew by 0.5 cm in 10 days, 2.3 cm in 20 days, and 7.4 cm in 40 days. Furthermore, PGA content increased by 12.5% in 10 days, 36.6% in 20 days, 44.8% in 30 days and 48.4% in 40 days, compared to the PGA content on the first day. Thus, we determined that potatoes stored at $20^{\circ}$C showed faster sprout growths and faster increases in PGA content than those stored at $5^{\circ}$C.

• The Korean Journal of Mycology
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• 제30권2호
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• pp.113-118
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• 2002

A Carboxymethyl Cellulase (CMCase) has been isolated and purified from the edible mushroom, Stropharia rugosoannulata. The molecular weight of CMCase was estimated to be 54 kDa by SDS polyacryl amide gel electrophoresis. The maximum activity of the purified CMCase was observed at pH 4.0 and $40^{\circ}C$, and stable for pH 3.0 to 11.0 to maintain 40% activity. The CMCase activity was activated by $AgNO_{3},\;MgSO_{4},\;and\;KCl$. However, its activity was inhibited by 1,10-phenanthroline, KCN and L-cysteine. Also, the enzyme activity was decreased by the addition of EDTA, suggesting that the purified CMCase is metalloenzyme.

• Journal of the Institute of Electronics and Information Engineers
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• 제54권1호
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• pp.11-17
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• 2017

In this paper, an 8-direction switched beamforming antenna system at 28GHz frequency band is described for 5th generation wireless communication. This system is composed of an $8{\times}8$ Butler matrix and an 8-element patch array antenna. The antenna system switches beams in 8-direction in the wide range of ${\pm}40^{\circ}$. The antenna spacing is $0.65{\lambda}$ to achieve ${\pm}40^{\circ}$ steering range. Designed results show that the 8-direction beams are placed at ${\pm}6^{\circ}$, ${\pm}17^{\circ}$, ${\pm}28^{\circ}$, ${\pm}40^{\circ}$ offset from the center. Parasitic radiation effect from the large dimension Butler matrix need to be suppressed by employing a stripline structure.

• Research in Community and Public Health Nursing
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• 제11권1호
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• pp.105-116
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• 2000

The purpose of this study is to evaluate the relationship of blood pressure with dietary habit and level of physical fitness of middle-aged male workers by age. The study subjects included 511 male employees who have worked at a company in C City, whose age was more than 40 years old. Between April 10 and May 30. 1998, all of the study subjects measured physical fitness (Balance, strength, power, agility, flexibility and endurance) and blood pressure. A questionnair was administered for dietary habit and socio-demographic characteristics. The average age (SD) of the study subjects was 46.61(3.98) years. The study subjects were classified by age into 3 groups; 40-44 aged group(34.6%), 45-49 aged group(41.3%), and 50-54 aged group (24.1%). The score of dietary habit of 40-44 aged group was $69.77{\pm}5.82$. that of 45-49 aged group was $69.77{\pm}5.83$, and that of 50-54 aged group was $71.85{\pm}6.82$(p=0.005). But age of health physical fitness tend to weaken in the age of 40-44. Systolic(p=.011) and Diastolic blood pressure (p= .011) were significantly increased with age increment. Diastolic blood pressure and dietary habit of 45-49 aged group showed the significant negative-correlation(r= .280. P<0.05). and Diastolic blood pressure and age of health physical fitness of 40-44 aged group showed the significant positive-correlation(r= .182. P<0.05). On the basis of the results of this study. I hope occupational nurses should play an active role to improve dietary habit and physical fitness for prevention of hypertension with increase of age in middle-aged male workers.

• The Journal of the Korea Contents Association
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• 제22권7호
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• pp.432-442
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• 2022

This study aimed to investigate depression, fatigue, and role-overload in nurses caring for COVID-19 patients and identify factors affecting depression. Data were collected from 142 nurses caring for COVID-19 patients at four designated COVID-19 hospitals using self-report questionnaires, from September 8, 2020, to September 17, 2020. The subjects' scores for depression, fatigue, and role-overload were 14.51±9.54, 3.19±0.64, and 3.30±0.64 points, respectively. Depression was positively correlated with fatigue (r=.40, p<.001) and role-overload (r=.30, p<.001), and fatigue was positively correlated with role-overload (r=.54, p<.001). Factors affecting depression included fatigue (β=.23, p=.014), health status (moderate: β=.28, p=.001; unhealthy: β=.26, p=.002), and hospital type (university hospital: β=.18, p=.024). The explanatory power (R²) of the model was 28.1%. In order to manage the nurse's depression level, a strategy for lowering the fatigue level and a strategy for improving the nurse's health statue are needed.

• Journal of Mushroom
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• 제13권3호
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• pp.185-191
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• 2015

This research was carried out to determine the differences of physiological activites between Grifola frondosa of log cultivation(LC) and Grifola frondosa of bottle cultivation(BC). Total flavonoids content, total phenolics content, electron donating ability(EDA), nitrite-scavenging ability(NSA), SOD-like activity and inhibitory effect of Xanthine oxidase were examined. The highest value of total flavonoid content is $5.96{\pm}0.81mg/g$ in water extract from Grifola frondosa of log cultivation at $40^{\circ}C$ (LC-W40) but, one of total phenolics compound is $44.53{\pm}0.89mg/g$ in water extract from Grifola frondosa of bottle cultivation at $40^{\circ}{\cdots}$ (BC-W40). The EDA using DPPH of BC-W40 extract showed the highest value of $97.14{\pm}0.71%$. Nitrite-scavenging ability was $62.55^{\circ}{\ae}0.36%$ in extract from Grifola frondosa of BC-W40 at pH 1.2. The value was SOD-like activity showed the highest value of $18.95^{\circ}{\ae}1.39%$ in extract from LC-W40. Xanthine oxidase inhibitory activity was the highest value of $54.31{\pm}0.40%$ in extract from Grifola frondosa BC-W40, and dependent on concentrations. These results showed that a the antioxidant effects of Grifola frondosa is excellent. However, physiological activities of Grifola frondosa were not depend on caltivation method regulary, and were different according to kind of solvents, concentraitions and physialogical factors examined such as EDA, SOD-like activity and NSA.

• Journal of Korean Society of Forest Science
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• 제94권4호통권161호
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• pp.258-263
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• 2005

Amounts of sap collected by DBH class and contents of mineral and free sugar in the sap of Acer mono for. rubripes indigenous in Geojedo were investigated. The collectable periods of sap of A. mono for. rubripes were 17 days and the total amount of sap was 193 l from 60 trees. Sap of A. mono for. rubripes were increased with increasing DBH, being 40 l (21 %), 49 l (25%) and 104 l (54%) from small, middle and large diameter tree, respectively. This may be due to increase in crown width and extention of root system. Amounts of sap was affected by temperature fluctuation between day and night. The pH and the contents of solid and sugar in the sap of A. mono for. rubripes were 6.5 and 2.40% and 1.99%, respectively. Free sugar determined in the sap was sucrose with 19.9 g/l, but glucose, fructose and maltose were not detected. The sap of A. mono for. rubripes contained seven kinds of minerals and the prominent minerals were Ca and K with their concentration being 441 mg/l and 383 mg/l, respectively.

• Journal of applied mathematics & informatics
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• 제1권1호
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• pp.79-84
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• 1994

The purpose of this paper is to introduce and discuss the concept of ${alpha}$-compactness for fuzzy topological spaces. And we obtain a product theorem for an arbitrary product of ${alpha}$-compact fuzzy spaces.