• 설비공학논문집
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• 제17권1호
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• pp.56-61
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• 2005

Indoor air quality becomes of a concern recently in view of human health. This study investigates the air diffusion performance and the air change efficiency of a classroom, when outdoor air is introduced in addition to the heating/cooling operation of a ceiling-mounted heat pump. A CFD analysis has been performed to investigate the effect of the discharge angle of the air jets from the heat pump for both parallel and series types of outdoor air system. It is observed that the series type creates more uniform indoor environment compared to the parallel type in general. It can be concluded the discharge angle should not be larger than 40o for the parallel type, in order not to generate thermal stratification in the room.

• 한국의상디자인학회지
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• 제14권2호
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• pp.33-47
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• 2012

The purposes of this study were to investigate the differences of self-efficacy and appearance management behavior according to demographic variables, to disclose the relationship between self-efficacy and appearance management behavior, and to examine the characteristics that affect appearance management behavior of male and female college students. The research method was a survey method using a questionnaire. The subjects were 632 college students (male: 302, female: 330) living in Seoul area. Statistical analysis methods were factor analysis, Cronbach's ${\alpha}$-reliability coefficient, t-test, ${\chi}^2$-test, one-way ANOVA, Duncan's multiple range test, Pearson's product-moment correlation coefficient, and multiple regression analysis. The self-efficacy factor derived four categories including self-control efficacy, social self-efficacy, physical self-efficacy, and task difficulty preference. The college students who were in higher social stratification and older had more appearance management behavior, and those who had lower task difficulty preference and lower physical self-efficacy had more plastic surgery management. Both men and women who had higher self-control efficacy had more clothing management. Women who had higher self-control efficacy, social self-efficacy, and task difficulty preference had more appearance management expenses.

• 대한기계학회논문집B
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• 제26권4호
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• pp.614-621
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• 2002

This study was performed to investigate the behavior of vapor phase of fuel mixtures with different piston bowl shapes(F, B and R-type) in a optically accessible engine. The images of liquid and vapor phases were captured in the motoring engine using exciplex fluorescence method. Fuel was injected into atmospheric nitrogen to prevent quenching phenomenon by oxygen. Injection pressure was 5.1MPa. Two dimensional spray fluorescence image of vapor phase was acquired to analyze spray behaviors and fuel distribution inside of cylinder. Four injection timings were set at BTDC 90$^{\circ}$, 80$^{\circ}$, 70$^{\circ}$, and 60$^{\circ}$. With a fuel injection timing of BTDC 90$^{\circ}$, fuel-rich mixture level in the center region was highest in a B-type piston. With a fuel injection timing of BTDC 60$^{\circ}$, R-type piston was best. R-type piston shape was suitable under enhanced swirl ratio and late injection condition and B-type piston shape was right in a weak swirl ratio. It was found that the piston bowl shape affected the mixture stratification inside of cylinder.

• Journal of Plant Biotechnology
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• 제6권4호
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• pp.213-219
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• 2004

Zygotic embryos were excised from immature and mature seeds of the Himalayan yew, Taxus wallichiana. The embryos germinated precociously when kept in darkness for 5 weeks and developed into full seedlings within 10-12 weeks. The highest rate of embryo germination ($81\%$) was obtained in modified Lloyd & McCown' s woody plant medium containing macro and micronutrients at half strength supplemented with $1\%$ activated charcoal, which supported both the best embryonic growth ($43\%$) and seedling development ($32\%$). However, the supplementation of basal media with kinetin, thidiazuron, 6-benzyl aminopurine or $GA_3$ had no effect on the germination of the embryos. The embryos derived from immature seeds germinated but the frequency of embryonic growth was better in mature seeds. Stratification of seeds effected precocious germination of embryos. Seeds kept at $4^{\circ}C$ for 1 week germinated earlier and at a higher frequency irrespective of the stage of seed maturity, while the germination rate declined with prolonged cold treatment for 1 month at that same temperature. Analysis of taxanes in germinating seedlings revealed that root tissues contained high levels of taxol, 10-deacetyl-baccatin ill and baccatin ill as compared to shoots. Thus embryo culture technique appears to overcome the lengthy dormancy requirement of T. wallichiana seeds.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.915-920
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• 2001

This study was performed to investigate the behavior of vapor phase of fuel mixtures with different piston bowl shapes(F, B, and R-type) in a optically accessible engine. The images of liquid and vapor phases were captured in the motoring engine using exciplex fluorescence method. Fuel was injected into atmospheric nitrogen to prevent quenching phenomenon by oxygen. Injection pressure is 5.1MPa. Two dimensional spray fluorescence image of vapor phases was acquired to analyze spray behaviors and fuel distribution inside of cylinder. Four injection timings were set at BTDC $90^{\circ},\;80^{\circ},\;70^{\circ},\;and\;60^{\circ}$. With a fuel injection timing of BTDC $90^{\circ}$, fuel-rich mixture level in the center region was highest in a B-type piston. With a fuel injection timing of BTDC $60^{\circ}$, R-type piston was best. R-type piston shape was suitable under enhanced swirl ratio and late injection condition and B-type piston shape was right in a weak swirl ratio. It was found that the piston bowl shape affected the mixture stratification inside of cylinder.

• 한국자원식물학회지
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• 제10권2호
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• pp.165-168
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• 1997

1. 맹아의 지상부 출현율은 외관상 눈이 있었던 근경의 경우 노천매장 후 $25^{\circ}C$의 온실내 포트에 이식한 근경에서 가장 높은 맹아출현율(95%)을 보였으며 외관상 눈이 없었던 근경의 경우에 노천매장 후 $15^{\circ}C$의 생장상내 포트에 이식한 근경이 75%로 가장 높은 맹아출현율을 나타냈다. 2. 외관상 눈의 유무에 관계없이 노천매장 후 $15^{\circ}C$의 생장상내 포트에 이식한 근경에서는 근경당 1개의 맹아가 출아되는 경향이었으며 노천매장 후 $25^{\circ}C$의 온실내 포트에 이식한, 외관상 눈이 있었던 근경에서 근경당 2개 이상의 맹아가 출아되는 경향이 현저하였다. 3. 외관상 눈의 유무와는 관계없이 층적매장 후 $25^{\circ}C$의 온실내 포트에 이식한 근경에서 출현한 개체의 초장이 가장 길었으며 외관산 눈이 있었던 근경의 경우에 충적매장 후 $25^{\circ}C$의 온실내 포트에 이식한 근경에서 출현한 개체가 최대의 엽면적을 나타냈다. 4. 외관상 눈이 있었던 근경의 경우에 노천매장 후 $25^{\circ}C$의 온실내 포트에 이식한 근경에서 출현한 개체의 뿌리가 가장 길었으며 이들 뿌리에서 새로 생성되어 출아한 신아수는 외관상 눈이 있었던 근경의 경우에는 무처리에서, 눈이 없었던 경우에는 층적매장에서 가장 많은 경향을 보였다.

• 한국전산유체공학회지
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• 제19권1호
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• pp.64-72
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• 2014

This study aimed at assessing the analysis capability of thermal-hydraulic computer code, MARS for the behaviors of the core make-up tank (CMT). The sensitivity study on the nodalization to simulate the CMT was conducted, and the MARS calculations were compared with KAIST experimental data and RELAP5/MOD3.3 calculations. The 12-node model was fixed through a nodalization study to investigate the effect of the number of nodes in the CMT (2-, 4-, 8-, 12-, 16-node). The sensitivity studies on various parameters, such as water subcooling of the CMT, steam pressure, and natural circulation flow were done. MARS calculations were reasonable in the injection time and the effects of several parameters on the CMT behaviors even though the mesh-dependency should be properly treated for reactor applications.

• 가정∙방문간호학회지
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• 제20권2호
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• pp.97-104
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• 2013

Purpose: The aim of this study is to examine the effects of physical activities on mental health of menopausal women. Method: The data was collected from 5th National Health and Nutrition Examination Survey. 810 samples of 40 to 64 year age group and 660 samples of 65 and over age group were used. To achieve the results estimated without bias stratification variables and colonies, descriptive statistics, Chi-square test, multiple logistic regression were used. Result: Flexibility exercises showed that it had an effect on stress and suicide intension of menopausal women. On the other hand, vigorous physical activity might be a stress factor of menopausal women. Conclusion: Menopausal women in 65 year and over appeared that they had more beneficial to low-intensity exercise to manage stress or suicide intension. This result will be used to develop the mental health promotion programs for menopausal women.

• 천문학회보
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• 제36권2호
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• pp.102.1-102.1
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• 2011

In this study we use three-dimensional magnetohydrodynamic simulations to investigate how the dynamic state of emerging magnetic field is related to the twist of field lines. Emerging magnetic field forms a magnetic structure on the Sun where various kinds of activity such as solar flares, jets, and coronal mass ejections are observed. To understand the physical mechanism for producing such activity, we have to know the dynamic nature of this structure. Since flares are the manifestation of rapidly dissipating electric current in the corona, we also investigate the distribution of current density inside the structure and examine how it depends on the field-line twist. To demonstrate the dynamic structure of emerging magnetic field, we focus on the factors characterizing the geometric property and stratification of emerging magnetic field, such as the curvature of field line and the scale height of field strength. These two factors show that emerging field forms a two-part structure in which the central part is close to a force-free state while the outer marginal part is in a fairly dynamic state where magnetic pressure force is dominant. We discuss how the field-line twist affects the two-part structure and also explain a possible relation between electric current structure and sigmoid observed in a preflare phase.

• 복식
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• 제59권8호
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• pp.97-109
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• 2009

The purposes of this study were to investigate the relationships between appearance interest, appearance satisfaction, and life satisfaction of adolescent, to disclose the differences of these variables according to demographic characteristics, and to examine the determinants of life satisfaction. The subjects were 322 teenaged girls (167 middle school students and 155 high school students) living in Seoul. The variables of appearance interest were plastic surgery, weight control, clothing interest, and hairstyle interest. Life satisfaction included school life satisfaction and daily life satisfaction. Appearance satisfaction had negative relationships with plastic surgery interest and weight control interest, while appearance satisfaction had no relationships with clothing interest and hairstyle interest. School life satisfaction and daily life satisfaction had negative relationships with plastic surgery interest. The upper class adolescents had high level of clothing interest and life satisfaction, and lower class adolescents had high level of plastic surgery interest and had low appearance satisfaction as compared to other classes. The adolescent group with high school grade had high level of appearance satisfaction, and the group with low school grade had high level of weight control interest. The life satisfaction was influenced by appearance satisfaction the most, and the next in the order by school grade, residence area, and weight control interest. The explanatory power of the four variables was 30.8%. Social stratification and whether mothers had an occupation or not had an indirect effect on the life satisfaction.