• Fisheries and Aquatic Sciences
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• 제26권11호
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• pp.639-648
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• 2023

The sea surface temperature (SST) and ocean heat content in the Korea Waters are gradually increased. Especially the increasing trend of annual mean SST in the Korea Water is higher about 2.6 times than the global mean during past 55 years (1968-2022). Before 2010s, the increasing trend of SST was led by winter season in the Korea Waters. However, this pattern was clearly changed after 2010s. The increasing trend of SST during summer is higher about 3.9 times than during winter after 2010s. We examine the long-term variations of several ocean and climate factors to understand the reasons for the long-term pattern changes of SST between summer and winter in recent. Tsushima warm current was significantly strengthened in summer compare to winter during past 33 years (1986-2018). The long-term patterns of Siberian High and East Asian Winter Monsoon were definitely changed before and after early- or mid-2000s. The intensities of those two climate factors was changed to the increasing trend or weakened decreasing trend from the distinctive decreasing trend. In addition, the extreme weather condition like the heatwave days and cold spell days in the Korea significantly increased since mid- or late-2000s. From these results, we can consider that the occurrences of frequent and intensified marine heatwaves during summer and marine cold spells during winter in the Korea Waters might be related with the long-term pattern change of SST, which should be caused by the long-term change of climate factors and advection heat, in a few decade.

• 진공이야기
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• 제3권4호
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• pp.14-18
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• 2016

본 원고에서는 2010년대 중반 현재 초고진공 환경에서 작동 가능한 저온 주사터널 현미경의 세계적 흐름을 정리 및 소개를 한다. 벡터형 초전도 자석을 장착한, 저진동 초고진공용 희석식 냉동기의 개발에 힘입어 수십 밀리 켈빈 이하의 온도 대 및 10 테슬라의 고자기장하의 실험 조건을 가지는 밀리 켈빈 주사터널 현미경이 세계 선도 그룹에서 속속 구축이 완료되고 있다. 또한 2000년대 중반 이후 본격적으로 시작된 1 켈빈 이하 고자기장 냉동기를 이용한 저온 주사 터널 현미경의 응용 범위 역시 넓어지고 있다. 튜닝 포크를 이용한 저온 원자 힘 현미경 및 저온 광자 주사터널 현미경을 이용한 연구도 활발히 진행되고 있다. 이러한 논의를 바탕으로 2020년대에 본격 출현할 초고진공 저온 주사터널 현미경의 흐름을 예측해 보겠다.

• 한국자원식물학회지
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• 제11권2호
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• pp.146-151
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• 1998

A study was carried our to investigate the characteristics of physico-chemical components palatability of cooked rice accoring to different transplanting time. The treatments were consisted of five transplanting time, from May 5 to July 5 at 15 -day intervals, and six cultivars ; two early-maturing, two mid-maturing and two late-maturing cultivars which are clearly identified by evaluation of cumulative temperature and growth duration from seeding to heading of rice plants. In gelatinization characteristics of rice grain, alkali digestion value was low in the earlier transplanting regardlessof maturing types. Initial pasting temeprature maximum viscosity and breakdown as amylogram charcteristics were high at the transplanting of June 5. The palatability of cookedrice was evaluated that early-maturing cultivars were much better in early transplanting than in late transplanting . The optimum transplanting time for palatibility was the periods from May 5 to 20 in early maturing varieties, May 20 to June 5 in mid-maturing and June 5 to June 20 in late-maturing ones at Honam district in Korea.

• 정신신체의학
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• 제5권2호
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• pp.195-204
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• 1997

Objectives : The behavioral and physiological effects following low doses and high doses of melatonin have not been fully explored. In this study the authors investigated the nature and extent of the hypnotic effects, oral temperature, blood pressure effects, performance effects and subjective feelings following the acute administration of low pharmacological oral doses of melatonin at mid-day. Methods : Thirty-five healthy young medical students were randomly assigned to receive 6mg of oral melatonin(N=11), 12mg of oral melatonin(N=12) or a placebo(N=12) in a double-blind, placebo controlled trial. Measures of the behavioral and physiological effects used in the study were Stanford Sleepiness Scale, Digit Symbol Substitution Test, Trail test and visual analogue scale for subjective feelings. Oral temperature and blood pressure were measured. The subjects were studied between 10:00 and 16:00 hours. Data were analyzed by using repeated-measures analyses of variance(ANOVA). Results: Melatonin produced statistically significant effects on oral temperature, but there were no significant effects on time and the $dose{\times}time$ interaction. There was a significant difference on oral temperature between the 12mg oral melatonin group and the placebo group at 12:00 and 16:00 hours, but no significant difference between the 12mg and the 6mg oral melatonin groups. Melatonin produced a dose-related increase in subjective sleepiness and had significant effects on time, the $dose{\times}time$ interaction. There was a significant difference on subjective sleepiness among the placebo, 6mg, 12mg oral melatonin groups at 13:00-16:00 hours. Melatonin did not produce statistically significant dose-related effects on subjective fatigue but produced significant effects on time and the $dose{\times}time$ interaction. There was a significant difference on subjective fatigue between the 12mg, the 6mg oral melatonin groups and the placebo group at 13:00 hour. Conclusions : These data indicated that acute administration of melatonin at mid-day increased subjective sleepiness and fatigue but decreased oral temperatures. These effects were shown especially in 12mg oral melatonin group.

• 천문학회지
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• 제37권4호
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• pp.159-169
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• 2004

This is a proposal to probe local part of the interplanetary dust (IPD) cloud complex and retrieve mean volume emissivity of the local IPDs at mid-infrared wavelengths. This will be done by monitoring, with Infrared Camera (IRC) aboard the ASTRO-F, the annual modulation of the zodiacal emission. In pointing mode of the ASTRO-F mission the spacecraft can make attitude maneuvering over approximately ${\pm}1^{\circ}$ range centered at solar elongation $90^{\circ}$ in the ecliptic plane. The attitude maneuvering combined with high sensitivity of the IRC will provide us with a unique opportunity observationally to take derivatives of the zodiacal emission brightness with respect to the solar elongation. From the resulting differential of the brightness over the ${\pm}1^{\circ}$ range, one can directly determine the mean volume emissivity of the local IPDs with a sufficient accuracy to de-modulate the annual emissivity variations due to the Earth's elliptical motion and the dis-alignment of the maximum IPD density plane with respect to the ecliptic. The non-zero eccentricity ($e_{\oplus}$= 0.0167) of the Earth's orbit combined with the sensitive temperature dependence of the Planck function would bring modulations of amplitude at least $3.34\%$ to the zodiacal emission brightness at mid-infrared wavelengths, with which one may determine the IPD temperature T(r) and mean number density n(r) as functions of heliocentric distance r. This will in turn fix the power-law exponent $\delta$ in the relation $T(r) = T_o(r/r_o)^{-\delta}$ for the dust temperature and v in $n(r) = n_o(r/r_o)^-v$ for the density. We discuss how one may de-couple the notorious degeneracy of cross-section, density, reference temperature $T_o$ and exponent $\delta$.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.172-172
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• 2022

The heading response of 40 genotypes, originated from South Korea, North Korea, and northern China, was tested under the temperature and day-length conditions of thirteen major rice production area in North Korea, with aims to select adaptable varieties to the given environment and crop period for each region. To simulate regional environment, seven-day mean temperature with 10℃ daily temperature range and day-length for each region were imposed at a weekly interval in the walk-in phytotrons. Olbyeo1, Olbyeo2 and Sonbong9 originated from North Korea, Kenjiandao3 and Nongdae3 from northern China, and Joun from South Korea demonstrated the earliest heading stage depending on the regional environment. Thirty-four varieties reached heading stage within the regional safe marginal heading date (SMHD) under Haeju and Sariwon conditions while 16-17 varieties reached the stage under Wonsan, Changjon, Supung, and Yongyon environment. Some of the middle and mid-late maturing varieties originated from South Korea could reach heading stage within SMHD under the temperature and day-length conditions of Kaesong, Haeju, Sariwon, Nampo, and Pyongyang located in west-southern plain. Majority of early maturing varieties, but not middle or mid-late ones, showed heading stage within SMHD under the conditions of Singye, Anju, Kusong and Sinuiju. Only some early maturing varieties demonstrated heading stage within SMHD under Yongyon, Changjon and Wonsan environment. These results provide basic information on the varieties able to complete their normal life cycle under the regional environment in North Korea. It it further suggested that yield performance of the selected varieties for each region in this study be tested to select high yielding rice varieties adaptable to North Korean environment.

• Animal cells and systems
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• 제1권1호
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• pp.53-61
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• 1997

Seasonal variation of the population structure and the reproductive pattern of the Korean striped field mouse, Apodemus agrarius, were investigated. High capture ratios in juveniles, young adult, and old adult mice were found during the period from October to November, from November to March, and from May to September, respectively, and extremely low capture ratios of old adults during the period from November to February were characteristic. It seemed that the young adults that survived during the winter might become older by summer and have been counted as the old adults. The breeding in the mice began earlier in males (from mid February or early March to late October) than in females (from mid March to late October), having a peak in August and September, and both the male and female mice weighing more than 20 g generally reached sexual maturation in general. In the breeding season, both young and old adult males had large testes with enlarged seminiferous tubules filled with numerous germ and Sertoli cells, and expanded caudal epididymides with a vast number of spermatozoa; the females had many Graafian follicles and corpora lutea in large ovaries, and developed uterine glands in the thick endometria. The lower ratios of the testis weight to the body weight in July and August in 1994 compared to 1995 seemed due to the extreme drought and considerably higher temperature in 1994, but the decrease in the ratio in mid-summer, only in the old mice, in both years might be explained partially by aging.

• 한국작물학회지
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• 제60권2호
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• pp.153-166
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• 2015

본 연구는 유색미 품종들의 적정 재배시기와 지역에 따른 색소발현 및 항산화 활성 변이를 분석하여 고품질의 유색미를 생산할 수 있는 적정 재배관리기술의 기초자료를 얻고자 수행하였고 그 결과는 다음과 같다. 1. 밀양, 봉화, 상주, 의성 4지역에서 이앙시기를 5월 20일, 6월 5일, 6월 20일 3시기에 걸쳐서 흑미 3품종과 적미 2품종을 재배한 결과 출수 후 30일간의 평균기온 $19.0^{\circ}C$ 이상에서 평균기온이 $1^{\circ}C$ 증가할 때마다 흑미의 안토시아닌 함량은 약 9.9%, 적미의 총폴리페놀 함량은 약 9%씩 감소하였다. 2. 유색미의 기능성물질 함량을 증대시키기 위한 출수 후 30일간 적정등숙온도는 흑미의 경우 조생종은 $22{\sim}23^{\circ}C$, 중만생종은 $21{\sim}22^{\circ}C$의 범위였으며, 적미도 $21{\sim}22^{\circ}C$범위였다. 3. 전국 지역별 30년간의 기상자료를 토대로 적정출수기를 추정한 결과 제천지역은 조생종이 8월 11일에서 8월 17일, 중만생종은 8월 25일경이며 보은지역은 조생종이 8월 15일에서 8월 19일, 중만생종은 8월 20일에서 8월 27일에 해당되었다. 영주지역은 조생종이 8월 15일에서 8월 21일, 중만생종은 8월 24일 경이었고, 충주지역은 조생종이 8월 17일에서 8월 23일, 중만생종은 8월 22일에서 8월 29일에 해당되었다. 대구지역은 조생종이 8월 27일에서 9월 2일, 중만생종은 9월 3일에서 9월 6일경으로 주요 재배적지는 제천, 보은, 문경, 영주 등이었다. 4. 적정파종기 추정결과 제천지역은 조생종이 5월 18일에서 5월 26일, 중만생종이 4월 11일 경이었으며, 보은지역은 조생종이 5월 23일에서 5월 28일, 중만생종이 4월 9일에서 4월 26일, 문경지역은 조생종이 5월 24일에서 6월 1일, 중만생종이 4월 21일에서 5월 4일, 영주지역은 조생종이 5월 22일에서 5월 30일, 중만생종이 4월 13일에서 4월 27일, 충주지역은 조생종이 5월 31일에서 6월 7일, 중만생종은 5월 4일에서 5월 14일 경으로 추정되었다.

• 지역연구
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• 제40권2호
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• pp.107-130
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• 2024

도시의 지표면 기온 변화는 도시민의 열 쾌적성, 에너지 소비, 나아가 건강에 영향을 미치는 주요한 환경요인이다. 많은 연구가 도시 지표면 기온과 도시 건조환경(built-environment) 형태 간의 관계를 탐색해 왔으나 대부분 극궤도위성 자료를 사용해 정오 시간대 기온만을 분석하였다. 본 연구는 다양한 시간대 지표면 기온을 관측하는 ECOSTRESS 위성 자료를 활용하여 서울시 여름철 지표면 기온의 주간 변동을 탐색하였으며 기온 변동이 건조환경 유형별로 차별적으로 나타나는지 분석하였다. ECOSTRESS는 2018년 발사된 NASA 위성으로 점진 변화 궤도를 운항하며 다양한 시간대 지표면 온도를 70m 고해상도로 관찰한다. 본 연구는 2019~2022년 이른 오전(6:25AM)과 늦은 오후(5:26PM)에 걸친 자료를 수집하여 서울시 지표면 온도의 시계열 자료를 구축하였다. 환경 특성을 반영하는 녹지, 수면, 건축 형태(건폐율, 용적률, 높이) 데이터를 기반으로 계층적 군집분석을 실시해 8가지 건조환경 유형을 도출하였으며, 유형별 온도변동 특성을 비교하였다. 각 유형은 저층고밀거주지(low-rise compact), 저밀아파트단지(low-BCR Apt.), 강변 중고층 주거단지(Riverside Mid-rise Apt.), 중고층 용도혼합지역(mid-to-high-rise mixed use), 고층고밀지역(high-rise compact), 초고층빌딩(skyscrapers), 산림, 수면(하천)을 나타내었다. 분석 결과, 지표 기온의 공간적 격차는 새벽 이후 증가하여 정오(12:04)에 극대화된 뒤 다시 감소하였으며, 기온 변화가 급격한 지역과 안정적인 지역이 구분되었다. 저층 고밀 거주지와 고층 고밀지역의 경우 기온이 빠르고 높게 증가하여 기온변동성이 높았고, 저밀 아파트단지는 기온이 온화하고 완만하게 증가하며 기온 변동성이 낮았다. 건조환경 유형 간 평균기온의 서열은 시간별로 변화하지 않고 유지되었다. 이러한 결과는 폭염과 일교차 증가에 적응할 수 있는 도시형태에 시사점을 제공한다.

• 대한기계학회논문집A
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• 제24권3호
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• pp.735-742
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• 2000

Densification behaviors of mixed metal powder under high temperature were investigated. Experimental data of mixed copper and tool steel powder with various volume fractions of Cu powder were obtained under hot isostatic pressing and hot pressing. By mixing the creep potentials of McMeeking and co-workers and of Abouaf and co-workers originally for pure powder, the mixed creep potentials with various volume fractions of Cu powder were employed in the constitutive models. The constitutive equations were implemented into a finite element program (ABAQUS) to compare with experimental data for densification of mixed powder under hot isostatic pressing and hot pressing. Finite element calculations by using the creep potentials of Abouaf and co-workers agreed reasonably well with experimental data, however, those by McMeeking and co-workers underestimate experimental data as observed in the case of pure metal powders.