• Journal of Families and Better Life
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• v.34 no.3
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• pp.65-84
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• 2016

This study examined the factors that were associated with longitudinal changes for ten years from 2004 to 2014 in time spent on housework by married couples who had a preschooler as their first-born child. It also sought to figure out how much of such temporal changes were attributable to differences in the means on associated factors as well as to differences in the influence or slope of such factors. A total of 9,668 time diaries from the Korean Time Use Survey were used to analyze the influence of couple's weekly work hours, wife's relative income, couple's education and gender role attitudes on the time spent on housework of husbands and wives. Results from descriptive statistics, regression and decomposition analysis were as follows. First, women decreased, while men increased their time doing housework. Second, weekly work hours of husband and wife were related to their time doing housework in every year surveyed. Third, wife's relative earnings and couple's gender role attitudes affected wife's time doing housework more than husbands', whereas couple's education had stronger effects on husbands than wives. However, such influence was apparent on a certain survey year, and then disappeared in another, or became stronger or weaker longitudinally. Fourth, the temporal decrease in wife's housework time and increase in husband's housework time were attributable to social and cultural changes such as reduced working hours, rising female income, higher educational background, and prevalence of egalitarian gender role attitudes. Findings suggest that the trend in spending time on housework is expected to continue, and provide a timely policy implications to facilitate the change.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.25 no.3
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• pp.191-203
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• 2018

Purpose: The purpose of this study is to investigate the problems experienced by Korean adolescents due to smartphone use and related factors. Methods: The subjects were 57,463 middle school and high school students nationwide as the 13th The Korea Youth Risk Behavior Web-Based Survey, 2017. Data were analyzed using means, standard deviations, and composite sample multiple logistic regression analysis. Results: This study confirms that negative experiences were related to general characteristics of sex, academic background, socio-economic level, residential area and form, academic performance, and parental education; health behavior characteristics of subjective health cognition, depression, and stress; and characteristics related to smartphone use. Smartphone usage time amd use of services were factors related to the problems experienced from using smartphones. Conclusion: Based on the results of this study, it is necessary to plan for the use of smartphones in consideration of physical and emotional health and to educate adolescents to promote social communication between family and friends. It is also necessary to develop and apply a smartphone use management program to maintain a balance between smartphone use, academic performance, and school life.

• The Journal of Korean society of community based occupational therapy
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• v.1 no.1
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• pp.29-39
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• 2011

Object : The relationships between the TSQ(Time structure questionnaire) and Well-being were examined. Methods : TSQ and questionnaire about Well-being were executed for 223 university students from April 26th to May 7th, 2010. The questionnaire adapted the item of the TSQ and Korean WHOQOL-BREF, SWLS(Satisfaction with Life Scale), LSES(Life Satisfaction Expectancy Scale), SHS(Subjective Happiness Scale). The questionnaires were distributed directly to the participants. Relativity between the TSQ and questionnaire about Well-being were analyzed using Pearson's correlation analysis. Results : As a result of the relationship between the TSQ and questionnaire about Well-being, overall there was a positive correlation. TSQ(sense of purpose, structured routine, persistence, past orientation) and questionnaire about Well-being showed a statistically significant correlation(p<.05). Conclusion : A structured time use and well-being by investigating the relationship, we were able to see the importance of time management. Currently, clinical occupational therapy focused on performance components, in future, intervention of personal time management to help make ones live well-being.

• Journal of The Korean Association For Science Education
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• v.24 no.6
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• pp.1118-1130
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• 2004

This article aims to (a) investigate children's images of a scientist's life style by comparing children's drawings about a scientist's schedule with those about a company employee's schedule in a weekday and on Sunday; and (b) examine the usefulness of 'Drawing A Scientist's Schedule (DASS)' test as a new instrument of learners' conceptions of a scientist and his/her work. To do those, thirty sixth- grade children participated in this study. The children, 15 boys and 15 girls, were selected from a classroom of an elementary school located in Gongju city. The children's drawings were analyzed in conjunction with individual interviews. The interviews facilitated the clarification of any ambiguous attributes of the drawings by questioning after their completion. Several significant conclusions can be drawn from this work: First, the children conceived that a scientist has more mandatory time, and less necessary and leisure time than does a company employee. Interestingly, many children thought that a scientist has similar life style on Sunday to that in a weekday, unlike a company employee. Second, in case of necessary time use in a weekday and on Sunday, the difference between a scientist and a company employee results from their sleeping time. Also, the children showed more various conceptions of a scientist's sleeping time than those of a company employee's sleeping time. Third, in case of mandatory time use, the children conceived that a scientist spends more time for his/her occupational work and less time for his/her housework activities than does a company employee. Fourth, the children's drawings showed that there is difference between a scientist's and a company employee's leisure time use and activities. Finally, the DASS test indicated its possibility and usefulness as an instrument for investigating learners' images on a scientist and his/her work. The instrument exhibited several distinctive children's conceptions that is difficult in identifying by using the DAST, a popular instrument.

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.23-27
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• 2006

This paper presents the evaluation of LPG (Liquefied petroleum gas) regulators for home use. For the evaluation, several properties of the regulators were experimentally analyzed, such as the operation of safety device, the adjusting and lock-up pressure, the adjusting spring and the diaphragm, with respect to the used time of the regulators. Experimental results showed that the initial operation performance of regulators were degraded with increase of the service time and also showed that the degradation of the performance and material property could become serious after six-year-use of the regulator.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.28-33
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• 2020

Plasma etching process employs high density plasma to create surface chemistry and physical reactions, by which to remove material. Plasma chamber includes silicon-based materials such as a focus ring and gas distribution plate. Focus ring needs to be replaced after a short period. For this reason, there is a need to find materials resistant to erosion by plasma. The developed chemical vapor deposition processing to produce silicon carbide parts with high purity has also supported its widespread use in the plasma etch process. Silicon carbide maintains mechanical strength at high temperature, it have been use to chamber parts for plasma. Recently, besides the structural aspects of silicon carbide, its electrical conductivity and possibly its enhanced life time under high density plasma with less generation of contamination particles are drawing attention for use in applications such as upper electrode or focus rings, which have been made of silicon for a long time. However, especially for high purity silicon carbide focus ring, which has usually been made by the chemical vapor deposition method, there has been no study about quality improvement. The goal of this study is to reduce surface roughness and depth of damage by diamond tool grit size and tool dressing of diamond tools for precise dimensional assurance of focus rings.

• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.1-6
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• 2021

Hydrogen is considered a cleaner energy source than fossil fuels. As a result, the use of hydrogen in daily life and economic industries is expected to increase. However, the use of hydrogen energy is currently limited because of safety issues. The rate of combustion of the hydrogen mixture is about seven times higher than that of hydrocarbon fuels. The hydrogen mixture is highly flammable and has a low minimum ignition energy. Therefore, it presents considerable risks for fire and explosions in all areas of hydrogen manufacturing, transportation, storage, and use. In this study, the auto-ignition characteristics of hydrogen were investigated numerically for diluted hydrogen mixtures. Auto-ignition temperature, a critical property predicting the fire and explosion risk in hydrogen combustion, was determined in well-stirred reactors. When N₂ and CO₂ were used to dilute the hydrogen/air mixture, the ignition delay time increased with increasing dilution ratios in both cases. The CO₂-diluted mixtures exhibited a longer ignition delay than the N₂-diluted mixtures. We also confirmed that lower initial ignition temperatures increased the ignition delay times at 950 K and above. Overall, the auto-ignition characteristics, such as the concentrations of participating species and ignition delay times, were primarily affected by the initial temperature of the mixture.

• Journal of Families and Better Life
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• v.14 no.3
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• pp.63-76
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• 1996

The purposes of this study were to examine; 1) the difference of the amount between husbands' and wife's leisure time in dual-earner household. 2) the relationship between leisure time of each spouse and selected demographic/socioeconomic measures and use of time in paid work and household work. Empirical survey was conducted by using structured questionaire and time-diary. The sample of this study were 98 dual-earner couples. The major findings were that; 1) the leisure time of husbands and wives were not significantly different on weekday. But husbands had significantly more leisure time than wives on Sunday : husband's mean minutes equal 444, while wife's mean minutes equal 350. 2) on weekday time spent in paid work and household work leisure time of spouse were significantly related to the leisure time of both husband and wife. In addition paid worktime of spouse was significantly related to the leisure time of husband. On Sunday household worktime leisure time of spouse w re significantly related to the leisure time of both husband and wife. 3) on weekday selected sociodemographic measures were not significantly related to the leisure time of both husband and wife. On Sunday degree of wife's education husband's income were significantly related to the leisure time of wife and age of younger child was significantly related to the leisure time of husband.

• Journal of the Korean Wood Science and Technology
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• v.27 no.4
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• pp.20-29
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• 1999

Temperature has important effect on mechanical properties of wood. These effect needs to be understood and taken into account in the structural use of wood. Furthermore, the effect of cooling after exposing to high temperature must be explained. In this study, the effect of temperature, exposure time, specific gravity, and cooling on bending properties were investigated. The boundary temperatures at which bending MOE and MOR reduced rapidly were approximately $200^{\circ}C$ and $150^{\circ}C$, respectively. This boundary temperature was nearly constant with independence of species(specific gravity), exposure time, and cooling. Above the boundary temperature, the effect of exposure time was increased with temperature and the reduction of bending MOE and MOR for Japanese Larch with relatively higher specific gravity was smaller than that of Hem-fir. The recovery of bending MOE and MOR after cooling was also more significant above the boundary temperature than below. The degree of cooling effect was larger for MOR than MOE. Consequently, bending properties of wood in elevated temperatures should be considered in terms of the boundary temperature, $200^{\circ}C$ for bending MOE, $150^{\circ}C$ for MOR, and these boundary temperatures must be considered an important factor. Furthermore, to evaluate the safety of structure, the recovery after cooling should be considered.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.2
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• pp.27-37
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• 1994

A survey was conducted to investigate consciousness of middle and high school students unsing fast food restaurants in Kwang-ju, from July 20 to August 20 in 1993. The results are follows; 1. There are many motives which drive students into fast food restaurants. Among those are its convenience as a place of meeting friends, pleasant and clean environment for eating, no time limit of staying there, hygiene of dining equipment and table ware. 2.The majority of the students used the fast food restaurants between 12:00 and 14:00 pm. It shows that time does not influence much on using there, because they answered in high percent that they use at any time. 3. Student usually pay individually and in some cases their friends or parents pay the bill. 4. Major factor in fast food selection was their tastes, nexts, were proper price, nutrition, and so on, They prefer their home food to restaurants fast foods. 5. The most of students have positive response to make traditional Korean foods into fast foods. The students, in particular, emphasized for the development of traditional Korean foods ; Sikhae and Sujonggwa(beverage), Docbokki, Japchae, kinds of rice cake and Jun. 6. Students suggested to be better fast food service, such as lowering the price, increasing the portion size and developing fast foods from the traditional Korean foods.