• 천문학회보
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• 제39권2호
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• pp.83.2-83.2
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• 2014

Flare and rotational variabilities induced by stellar activity are important for studying the effect of magnetic fields on the evolution of red dwarf stars. The level and frequency of magnetic activity in these stars have a different aspect at every moment of the observations due to the effect of age-rotation relation. The use of both tracers is thus essential to have a relatively homogeneous set of stellar activity data for statistical studies. The archival light curves and imaging data of the open cluster M37 taken by MMT 6.5m telescope were used for this work. In order to achieve much more accurate photometric precisions and also to make the most efficient use of the data, the entire imaging database were re-analyzed with our new time-series photometry technique and carefully calibration procedures. Based on the new light curves, we study, for the first time, a variety of aspects of those two variabilities in red dwarfs and their relation to magnetic activity. In this talk, we present all observational evidences that support the idea that the strength of magnetic activity is closely connected with the rotation rate of a star and its evolutionary status (age-activity-rotation paradigm). In conclusion, we suggest future directions to improve our understanding of stellar activity in cool stars with photometric time-series data.

• Journal of Astronomy and Space Sciences
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• 제23권2호
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• pp.135-142
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• 2006

흑점수와 오로라의 관측 자료를 과거로 연장해 보면 dynamo 이론과 태양의 활동 그리고 기후간에 상당한 관계가 있음을 알 수 있다. 특히 흑점이 거의 나타나지 않았던 Maunder 극소기가 이상 혹한기였던 유럽의 소빙하기와 일치하고, 흑점의 출현과 오로라 발생 사이에 밀접한 관계가 있다는 사실이 알려졌다. 이에 따라 Maunder 극소기 시기의 흑점과 오로라의 관측 자료들을 간접적 solar proxy 자료들과 함께 조사하고, 이 시기에 나타난 태양 활동의 모습과 특징을 기후변화의 관계와 함께 알아보았다.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.307-308
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• 1989

• 한국심리학회지 : 문화 및 사회문제
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• 제8권2호
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• pp.17-31
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• 2002

본 연구는 지금까지 여가현상 규명의 영역이 체육학이나 관광학등에 편향되어왔음을 지적함과 동시에 여가 활동, 여가참여동기, 자기효능감 및 주관적 안녕감간의 관계를 통해 한국문화권에서의 여가 현상을 이해해보기 위해 수행된 것이다. 구체적인 연구문제로 1) 한국의 여가동기와 여가활동의 양상, 2)각 여가동기와 자기효능감간의 상관관계 그리고 3)각 여가동기와 주관적 안녕감간의 상관관계를 설정하였고, 대학생 270명을 통해 연구결과가 크게 3가지로 나타남을 확인할 수 있었다. 첫째, 여가동기는 자기개발 및 자기향상동기와 정서 및 심리적 안정추구동기로 나누어지며, 전반적인 여가활동은 소위 정적이며 소극적이라고 불리어지는 활동들이 나타났고 둘째, 분류된 두 동기에 따른 개개인의 자기효능감간에는 유의미한 관계가 나타나지 않았으며 셋째, 정서 및 심리적 안정추구동기로 여가를 경험한 개인이 자기개발 및 자기향상동기로 여가를 경험한 개인보다 주관적 안녕감과 유의미한 관계가 있었다. 위와 같은 연구결과들은 여가활동과 여가동기에 대한 문화적 인식에 따라 여가현상에 대한 이해 및 인식이 달라질 수 있음을 시사해준다. 마지막으로 본 연구의 함의, 제한점과 향후 연구 방향을 논의하였다.

• 한국전문물리치료학회지
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• 제27권3호
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• pp.171-177
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• 2020

Background: The flexion-relaxation phenomenon (FRP) refers to a sudden onset of activity in the erector spinae muscles that recedes or fades during full forward flexion of the trunk. Lumbar spine and hip flexion are associated with many daily physical activities that also impact trunk flexion. Shorter hamstring muscles result in a reduction of pelvic mobility that eventually culminates in low back pain (LBP). Many studies have explored the FRP in relation to LBP. However, few studies have investigated the influence of hamstring muscle length on the FRP in relation to the erector spinae muscles during trunk flexion. Objects: This study aimed to investigate the influence of hamstring muscle length on the FRP in relation to the erector spinae muscles during trunk flexion. Methods: Thirty subjects were divided into three groups according to hamstring length measured through an active knee extension test. The 30 participants consisted of 10 subjects who had a popliteal angle of 20° or less (Group 1), 10 subjects who had a popliteal angle of 21°-39° (Group 2), and 10 subjects who had a popliteal angle of 40° or more (Group 3). A one-way analysis of variance was used to compare the difference in muscle activity of the erector spinae muscles during trunk flexion. Results: The subjects with a shorter hamstring length had significantly higher muscle activity in their erector spinae muscles during trunk flexion and full trunk flexion (p < 0.05). The subjects with a shorter hamstring length also had a significantly higher flexion-relaxation ratio (p < 0.05). Conclusion: The results of this study demonstrate that differences in hamstring muscle length can influence the FRP in relation to the erector spinae muscles. This finding suggests that the shortening of the hamstring might be associated with LBP.

• 가족자원경영과 정책
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• 제7권1호
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• pp.23-39
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• 2003

The purpose of this study is to develop the life scale of the middle aged homemakers. The life scale are composed of spouse relation 8 items, child education relation 7 items, home economy relation 4 items, homework relation 3 items, selfish health relation 6 items, parent relation 3 items, and interest and social activity relation 4 items. The reliability coefficient of the development scale was Cronbach'α =.83 and the correlations of each demesne was high. For the better future life in this study, the middle aged homemakers are needed the improvement of conjugal relations, the child education, the health, the interest, and the enlargement of social relations. This life scale can help to evaluate their middle age, and to the planning of energetic healthful future, and useful to understanding characteristic and the developmental task of middle aged homemakers.

• Archives of Pharmacal Research
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• 제13권2호
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• pp.132-135
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• 1990

Polyhydroxystilbenes including resveratrol were reported to competitively inhibit monoamine oxidase-A-without structural relation with substrates and cynthetic inhibitors for the enzyme. We attempt to explore a plausible mechanism for their inhibitory activity on MAO-A. All the polyhydroxystilbenes tested showed the antioxidant activity on liver homogenate. Furthermore, the antioxidant activity turned out to closely correlate with the MAO-A inhibitory activity.

• 생명과학회지
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• 제14권4호
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• pp.614-619
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• 2004

This study was undertaken to investigate the different responses of cultured plant cells to paraquat treatment and nucleus-DNA damage in relation to enzyme activity of superoxide dismutase (SOD). Furthermore, this study was also carried out to understand the antioxidative mechanism of plant cells to environmental stress. We selected two different species of plant cultured cells, Ipomoea batatas as high-SOD species and Lonicera japonica as low-SOD species. The total activity and specific activity of SOD in a chlorophyllous cell of I. batatas were 3,736 unit/gㆍfresh weight and 547 unit/mgㆍprotein, respectively, and those in L. japonica were 23 unit/gㆍfresh weight and 13 unit/mgㆍprotein, respectively SOD activity in chlorophyllous I. batatas cells reached its maximum level at 10 to 15 days after subculture, whereas that in L. japonica remained at a very low SOD level during the whole period of subculture. In comparison to L. japonica, I. batatas, a high-SOD species, showed high tolerance to paraquat 10 and 50 mg/l treatment in terms of cell viability and electrolyte leakage. Based on the result of comet assay, the nucleus-DNA damage of two species by paraquat 50 mg/l treatment was not significantly different. However, I. batatas cells repaired their damaged DNA more effectively than the cells of the low-SOD species, L. japonica.

• Journal of Nutrition and Health
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• 제37권5호
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• pp.385-393
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• 2004

This study examined the relations of educational level and life-style behaviors to the obesity. A total of 507 male adults aged 30 - 50 years completed the self-reported questionnaires. Educational level was used for measuring socioeconomic status. Activity at work, leisure-time activity and TV watching were measured for life-style behaviors related to physical activity, and some demographic and family history of disease as well. Subjects were categorized as obese when BMI was equal to or over 25kg/$m^2$, in which 19.7％ resulted obesity. Using multivariate logistic regression, the association between the measured factors and obesity was assessed. The odds ratios (OR) for risk of obesity did not differ with either age or monthly income. Subjects who completed high school (OR = 0.36; 95％ CI = 0.20 - 0.66) or university (OR = 0.34; 95％ CI = 0.16 - 0.71) had lower risk of obesity than those with education below middle school. Those with moderate activity level at work (OR = 0.41; 95％ CI = 0.24 - 0.72) showed lower risk of obesity than in inactive ones. The subjects watching TV more than 3.5 hr/day presented higher risk of obesity (OR = 2.46; 95％ CI = 1.28 - 4.74), compared with those watching TV less than 1.5 hr/day. The higher risk of obesity observed in high level of leisure time activity than in low one was considered due to that physical activity at work and leisure-time might counteract each other. Educational level and activity at work or leisure-time activity or TV watching were jointed and categorized, and then OR for obesity was estimated. The extent of obesity risk at a given level of each work activity or leisure-time activity or TV watching was different depending the educational level, which was significantly high when educational level was below middle school. Educational difference had no effect on activity level at work. However, higher educational attainment increased the leisure activity and reduced TV watching (p＜0.05), indicating that low education tended to contribute to more sedentary life-style. The findings of this study is concluded that low education was related to obesity in adult males, and its relation can partly be explained through acquiring inactive life-style behaviors. Individuals with low education might be more susceptible to the risk factors of obesity.

• 신재생에너지
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• 제9권1호
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• pp.51-59
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• 2013

Tantalum carbide crystallites which is to be used for $H_2$ fuel cell has been synthesized via a temperature-programmed reduction of $Ta_2O_5$ with pure $CH_4$. The resultant Ta carbide crystallites prepared using two different heating rates and space velocity exhibit the different surface areas. The $O_2$ uptake has a linear relation with surface area, corresponding to an oxygen capacity of $1.36{\times}10^{13}\;O\;cm^{-2}$. Tantalum carbide crystallites are very active for hydrogen production form ammonia decomposition reaction. Tantalum carbides are as much as two orders of magnitude more active than Pt/C catalyst (Engelhard). The highest activity has been observed at a ratio of $C_1/Ta^{{\delta}+}=0.85$, suggesting the presence of electron transfer between metals and carbon in metal carbides.