• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.319-327
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• 2010

We examine the ionospheric F2-layer electron density variation by solar activity in middle latitude by using foF2 observed at the Kokubunji ionosonde station in Japan for the period from 1997 to 2008. The semi-annual variation of foF2 shows obviously in high solar activity (2000-2002) than low solar activity (2006-2008). It seems that variation of geomagnetic activity by solar activity influences on the semi-annual variation of the ionospheric F2-layer electron density. According to the Lomb-Scargle periodogram analysis of foF2 and Ap index, interplanetary magnetic field (IMF) Bs (IMF Bz <0) component, solar wind speed, solar wind number density and flow pressure which influence the geomagnetic activity, we examine how the geomagnetic activity affects the ionospheric F2-layer electron density variation. We find that the semi-annual variation of daily foF2, Ap index and IMF Bs appear clearly during the high solar activity. It suggests that the semi-annual variation of geomagnetic activity, caused by Russell-McPherron effect, contributes greatly to the ionospheric F2-layer semi-annual electron density variation, except dynamical effects in the thermosphere.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.1
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• pp.15-20
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• 2014

Background: The purpose of this study was to investigate the effect of differing insole height on the electromyographic (EMG) activity and muscle fatique in tibialis anterior and gastrocnemius a lot of repeat college students from the desk during a sit to stand activity. Methods: For the 20 subjects (males), let them wear insole in order. Using EMG equipment measured the difference in muscle activity and muscle fatigue degree. All subjects measured for 3 seconds in standing up from the chair. It's measured total 3 times. Results: The summary of results stated above is as follows: It's sitting to standing activity when there were no significant differences between the muscles. But sitting activity in muscle fatigue-calf muscle during standing activity correlated only. Conclusion: The results of this study, the height of an adult male lead in adequate to maintain a healthy foot function and health elements of effective and aesthetic elements based on a significance in that it presents.

• Korea Trade Review
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• v.46 no.5
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• pp.195-211
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• 2021

The purpose of this study is to examine the relationship among innovation activities, innovation performance, and management performance of export firms. I first undertake a review of previous studies related to innovation activity, innovation performance, and export firms' innovation. Based on this, I set up a research model and hypotheses. First, The innovation activity is classified into product innovation activity, process innovation activity, and administrative innovation activity. Innovation performance is divided into product quality improvement and cost reduction. And the business performance is regarded as financial performance of export's firms. This study examined whether innovation activity affect innovation performance such as product quality improvement and cost reduction. In addition, I examined whether these innovation performance affects business performance (financial performance). To achieve this, a total of 368 questionnaires are used in this study and PLS (Partial Least Square) was used to analyze structural equation. As a result, this study shows that product innovation activity have a positive effect on product quality improvement, and process innovation activity also have a positive effect on product quality improvement. However, it was found that neither product innovation activity nor process innovation activity had an effect on cost reduction. And it was found that administrative innovation did not affect product quality improvement, but had a positive effect on cost reduction. Also, it was found that quality improvement, which is an innovation performance, did not affect the financial performance of export's firms, and cost reduction, which is an innovation performance, had a positive effect on the financial performance of the export's firms.

• Korean Journal of Health Education and Promotion
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• v.33 no.4
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• pp.47-54
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• 2016

Objectives: The prevalence of insufficient physical activity is relatively high in the Republic of Korea and it is increasing. The national strategies to improve physical activity are essential and are suggested in this paper. Methods: National level of physical activity is compared globally by WHO statistics. Korean National Health and Nutrition Survey showed the level of physical activity. National strategies to improve physical activity were suggested referring to the other countries' strategies, public health books and Health Plan 2020. Results: Prevalence of insufficient aerobic exercise in 2010 were 33.4%, 94.8% in over and 18 years old, 11~17 years old, respectively. And it is increasing. Sufficient exercise to fit the national guidelines of physical activity were done by 15.6% of Korean older and 19 years old. Prevalence of insufficient physical activity was high in the elderly, female, adolescent, rural area and lower income. The national spread of the physical activity guidelines, primary care physicians involvement, supports for the physical activity programs, development of the evaluation protocol for the programs and environmental supports are suggested. Conclusions: The government induced various efforts to improve the level of physical activity is needed urgently.

• The Journal of Korean Society for School & Community Health Education
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• v.19 no.3
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• pp.109-121
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• 2018

Background & objectives: Life style modification reduces the health risks of young people and improves their health status. Physical activity is known the effective factor to reduce health risks and health problems. This study performed to analyze health promotion behaviors related to physical activity among first-year students of university. Methods: To examine the association with physical activity and health promotion practices, health survey was conducted with 3,806 students who were first-year students in a university by self-reported questionnaire from February 26 to March 10, 2015. Multiple logistic regression analysis was performed to identify the difference of health promotion behaviors by physical activities. Results: 51.4% of the first-year student was regular exercisers who had practiced on regular walking exercise or regular strength exercise or regular aerobic exercise for a week. 87.8% of students exercised one or more times within the last one week. On the other hand, 12.2% of them did not exercise. In multiple logistic regression models, it remained significantly the difference of regular exercise by gender, subjective health status, sleeping time per one day, BMI, drinking behavior, and eating habit (p<0.05, p<0.01, p<0.001). Also it remained significantly the difference by physical activity type, such as walking, strengthen, and aerobic exercise (p<0.05, p<0.01, p<0.001). Conclusion: To help the achievement of academic goal, it should build physical activity policies and comprehensive health promotion programs to reduce health risk factors of university students. Comprehensive university health services and customized program for university students could help to make the best of their health. In future, to enhance physical activity practice, it needs to develop various tailed messages and smart healthcare service using health information technology (IT) on campus.

• Journal of Environmental Health Sciences
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• v.17 no.2
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• pp.121-126
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• 1991

To clarify a cause of increased serum level of acid phosphatase in CCl$_{4}$-treated rats, the acid phosphatase activity of liver was compared with that serum. Concomitantly, the serum and liver acid phosphatase activity of CCl$_{4}$-treated rats were compared with that of CCl$_{4}$-treated rats pretreated with prednisolone or actinomycin D. In CCl$_{4}$-treated rats, the activity of serum acid phosphatase was significiantly increased whereas that of liver acid phosphatase was rather slightly decreased. the pretreatment of prednisolone led to the decreased activity of serum and liver acid phosphatase in CCl$_{4}$-treated rats. But the pretreatment of actinomycin D rather increased the activity of liver and serum enzyme. In conclusion, it is likely the increased activity of serum acid phosphatase is based on the excess leaking of acid phosphatase into blood by the increased membrane permeability of both liver cell and lysosome in it.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.2
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• pp.185-197
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• 1998

Engineering design involves the specification of many variables that define a product, how it is made, and how it behaves. Before some variables can be determined, other variables must first be known or assumed. This fact implies a precedence order of the variables, and of the tasks of determining these variable consequently. Moreover, design of complex systems may involve a large number of design activities. In this paper, the activity-activity incidence matrix is considered as a representation of design activity analysis which mainly focuses on the precedence constraint. In order to analyze the activity-activity incidence matrix, a heuristic algorithm is proposed, which transforms an activity-activity, parameter-formula, and parameter-parameter incidence matrix into a lower triangular form. The analysis of the structured matrices can not only significantly reduce the overall project complexity by reorganizing few critical tasks in practice, but also aims at obtaining shorter times considering the solution structure by exploring concurrency.

• Korean Journal of Pharmacognosy
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• v.48 no.3
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• pp.208-212
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• 2017

In this study, analysis of active compounds that are believed to be highly relevant to antioxidant activity was carried out on the methanol extract and its solvent fractions of Corni fructus. The DPPH radical scavenging activity for the comparison of antioxidant activity was higher in order of aqueous fraction > methanol extract > ethyl acetate fraction > n-hexane fraction. It is similar to the order of total polyphenol contents in the samples. As a result of LC-MS analysis, phenolic acid compounds such as caffeic acid, gallic acid and chlorogenic acid and lognin, which is known as a representative active ingredient of Corni fructus, were identified as active compounds. And the antioxidative activity and the total polyphenol content of the extracts and solvent fractions were found to be related to the contents of the compounds. Particularly, it was confirmed that phenolic acid such as caffeic acid contributes to the antioxidative activity of the aqueous fraction of Corni fructus methanol extract.

• The Korean Journal of Physiology
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• v.5 no.2
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• pp.9-14
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• 1971

The direct effects of various agents on the phosphorylase activity of rat kidney was studied in vitro and the results were summarized as follows. 1. The kidney phosphorylase activity was markedly depressed by iodoacetic acid whereas it was increased by sodium azide. 2. DNP had no effect on the phosphorylase activity, while sodium cyanide slightly increased the activity of the enzyme. 3. Ouabain slightly depressed the phosphorylase activity whereas it was markedly depressed by oligomycin. 4. Vasopressin and histamine markedly increased the phosphorylase activity.

• Journal of Plant Biology
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• v.17 no.1
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• pp.3-8
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• 1974

The experiments were conducted to examine the effects of sulfur dioxide on catalase activity in germinating seeds under dark conditions and in green plants under light conditions. Three kinds of plants, bean (Glycine max M.), cabbage (Brassica oleracea L. Chungbang No.1) and rice (Oryza sativa L. Suwon No.213-1) were used in this study. Both thegerminating seeds and the leaves were treated with various concentrations of sulfur dioxide for both one green plants with two and twelve hours. In the results of the measurement of catalase activity it was found that plant injuries by sulfur dioxide for the period of photosynthesis were higher than those for the period of respiration. In the control, apparent catalase activity under the light condition of photosynthesis showed a considerable decrease in comparison with catalase activity under the dark condition of respiration. This tendency also appeared markedly in the gas treatment. In the gas treatment for twelve hours, the decrease of catalase activity was higher than that of one hour in both photosynthesis and respiraton. It was thought that sulfur dioxide was an inhibitor of catalase activity in higher concentration of the gas.