• Korean Journal of Optics and Photonics
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• v.17 no.3
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• pp.273-277
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• 2006

In this paper, we constructed the Littman type and fixed Littrow type tunable external-cavity diode laser systems. The laser output, which is the 0th-order diffracted beam from the diffraction grating in an external cavity, was the single longitudinal mode. Its FWHM was measured as less than 9MHz. With the diode driving current of 140mA and operating temperature of $25^{\circ}C$, the coarse tuning range of 5.375nm was measured for the Littman type, and of 13.65nm was measured for the fixed Littrow type. A fine tuning experiment in which an external mirror was rotated by a PZT driven by a sawtooth wave was performed, and its tuning range of 0.042nm was measured for both types. The fixed Littrow type tunable external-cavity diode laser system was an improvement on the conventional Littrow type tunable laser system in which the output direction varies due to the grating embedded in the mirror plate.

• Korean Journal of Human Ecology
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• v.16 no.5
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• pp.1051-1059
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• 2007

This study intends to find out possible variations in physical properties and color of hair depending on dye type(acidic and alkalic) and permanent treatment/hair dyeing procedure. To meet the goals, healthy hair samples were taken from 5 women's hair speciment in 20's without experiencing in any harmful substance via long-term medications. and beauty care using chemicals. To get possible findings depending upon hair dye type and treatment procedure, both acidic and alkalic hair dye were applied on some specimens after permanent treatment, while on other specimens before permanent treatment. In order to determine scale damage, this study used SEM(Hitachi S-2500C) both hair thickness and tensile strength were measured with optical microscope(Nikon, MM-60/L3T) and Instron (4482-standard). Wave configuration was measured transverse and longitudinal round diameter. The chromaticity of each specimen was measured using a spectrocolorimeter(Color Techno System, JP/JX-777) with visual $C/2^{\circ}$ (at $2^{\circ}$ with C light source) monitor fixed to determine Lab and CMYK values. As a result, it was found that hair specimens were more significantly damaged with alkalic hair dye treatment than with acidic hair dye treatment, while hair specimens were more effectively dyed with the former hair dye type than with the latter one. For possible results depending on treatment procedure, it was found that hair specimens were less damaged but more effectively dyed with permanent treatment followed by hair dyeing than vice versa. Therefore, it was concluded that permanent treatment followed by acidic hair dyeing would be more effective in reducing hair damages.

• Journal of Family Resource Management and Policy Review
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• v.17 no.2
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• pp.173-194
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• 2013

The purpose of this study was to examine the association between time-income availability and health-promoting behavior (physical practice, smoking, alcohol consumption) of older males (55-69). This study attempted to shed light on health-behavior changes during the transition period of male retirement. The availability of time resources was examined by addressing the amount of weekly paid labor hours. The availability of financial resources was calculated by using the debt-income ratio. The study sample comprised 1,372 (age range 55-69) male respondents of the 2006 Korean Longitudinal Study of Aging (2006 KLOSA wave 1). The results of CHAID (CHi-squared Automatic Interaction Detection) analysis uncovered four distinctive combinations of resource types: time-money poor, time rich, money rich, time-money rich. According to logit results, these four groups had different socio-demographic profiles and different health-behavior risks. The time-money poor males were unlikely to perform physical activities needed to improve their health or to quit smoking or alcohol consumption. This group was also more likely to consume alcohol compared to the time-money resource types. In contrast, the time-money rich group was more likely to exercise longer and more frequently than the reference group (time and money poor). The time-rich types, those who have time-only resources and less money, were likely to be smokers and have problems with alcohol consumption.

• The Journal of the Korea Contents Association
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• v.13 no.4
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• pp.218-229
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• 2013

With the increase of the aging population in Korea, the welfare of Korean elderly has become one of main concerns of the society. One essential factor that may enhance the quality of life of the elderly is the active social participation. Involvement in the volunteer activity is one form of social participation that benefits both society and individual. The purpose of this study is to examine the level of Korean elderly's participation in volunteer activities and factors related to their participation in the context of different age group. People aged 55 and over from wave 2 data of Korean Longitudinal Study of Ageing are grouped into pre-old(55-64), young old(65-75), and old old (75 and older). Main analytic tools include descriptive statistics and logistic regression analysis. Results indicated that social relationships of the elderly were the most important factors related with their participation with voluntary activities. Also highlighted is the importance of considering the diversity among the older population.

• Korean Journal of Childcare and Education
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• v.13 no.2
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• pp.21-37
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• 2017

Objective: The current study aimed at examining the mediation effects of children's self-esteem and self-control in learning between perceived academic achievement at $4^{th}$ grade and $6^{th}$ grade. This article proposes that perceived academic achievement boosts self-esteem and self-control in learning and both in turn, influence subsequent perceived academic achievement. We especially attempted to empirically prove that a serial multiple mediation of self-esteem and self-control in learning between the perceived academic achievement at two time points exists. Methods: We analyzed the longitudinal data of 1,881 children from the $4^{th}$ to the $6^{th}$ wave data of the '2010 Korea Children and Youth Panel Survey (KCYPS)' by means of a Hayes's PROCESS(2012) program. Results: The results revealed that perceived academic achievement at $4^{th}$ grade influenced children's self-esteem and self-control in learning at $5^{th}$ grade. Children' self-esteem and self-control in learning subsequently predicted perceived academic achievement at $6^{th}$ grade. Children's self-esteem significantly predicted self-control in learning supporting the hypothesis of serial multiple mediation. Conclusion/Implications: In conclusion, children's self-esteem and self-control in learning behaviors both mediated the association between perceived academic achievement at $4^{th}$ grade and at $6^{th}$ grade. The findings imply the importance of consideration of both psychosocial and behavioral aspects in understanding the academic performance during childhood.

• Journal of Families and Better Life
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• v.33 no.2
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• pp.89-101
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• 2015

This study examined the effects of self-differentiation and psychological discomfort on antenatal attachment of pregnant couples in their third trimester of pregnancy. The subjects were 182 couples in J province who had participated in the first wave of the Korea Attachment Longitudinal Study (KALS). Data were analyzed by means of frequency, percentages, Pearson's correlations, and stepwise multiple regression models using SPSS 20.0. The findings were as follows. First, the independent t-test showed that the mean scores of pregnant women's self-differentiation were lower than their spouses in all subscales except emotional cutoff, and higher than in all psychological discomfort subscales. There was no significant difference in antenatal attachment quality between women and men, but the pregnant women significantly spent more time thinking about the fetus than their spouses. Second, the stepwise multiple regression models revealed that pregnant women's emotional cutoff in self-differentiation influenced the most on both quality and quantity of antenatal attachment. Among subscales of their spouses' self-differentiation, only emotional reactivity had an impact on quality of antenatal attachment, and fusion with others had the most impact on quantity of antenatal attachment. Among the pregnant women's and their spouses' psychological discomfort subscales, only depression influenced each quality and quantity of antenatal attachment. This is the very first and only study in which the impact of the pregnant couples' self-differentiation on antenatal attachment has been examined.

• Journal of Families and Better Life
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• v.33 no.2
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• pp.149-164
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• 2015

In recent years, leisure time has received increasing attention in Korean society. Despite the growing interest, however, there are very few studies that explored shared leisure time, especially among married couples. In this light, the present study examined variations in shared leisure time by demographic characteristics and associations between shared leisure time and quality of marital relationship. We used the third wave of the national data KLoWF (Korean Longitudinal Survey of Women and Families, 9,997 19-64 years old women). The study sample included 5,965 married women with no prior history of divorce. Results showed that Korean wives reported very little shared leisure time with their husbands. Given that the mean of the shared leisure time reported by employed women was significantly lower than that of the un-employed, we speculated that the time constraint may be one of the major barriers to having leisure time with one's spouse among Korean married couples. Married women in their 30's had the most frequent couple leisure time. The younger wives in their 20s had more cultural leisure time with their husbands, but sharing outdoor leisure time was not related to their age. The higher level of education for women was associated with greater shared active leisure time. However, visiting a husband's family often took place regardless of the wives' education level. After controlling for age, years of education, job status and annual family income, shared active leisure time (i.e., cultural activity and exercise) was positively related to marital satisfaction. Visiting one's own family, however, was not considered a leisure activity for Korean wives. Rather, frequent family visits were related to lower marital satisfaction. Findings shed light on how leisure life of married women with spouses are intertwined with not only their socioeconomic status and but also marital relationship in culturally unique ways.

• Journal of Digital Convergence
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• v.16 no.7
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• pp.429-439
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• 2018

The objective of the study was to analyze difference in cognitive function according to social isolation level in elderly Korean. The author classified the social isolation into the structural isolation and contact isolation. Structural isolation corresponded to the no spouse or no children and the contact isolation corresponded to the absence of contact with children, friends or social association. Author conducted multivariate regression analysis with the elderly people aged 65 years or older from the 5th wave of the Korean Longitudinal Study of Ageing data. Number of sample was 3,971. It was confirmed that the level of cognitive function was lower according to level of social isolation. It was also confirmed that friends/neighborhood isolation, and social activity isolation showed significant relationships with cognitive functions. Based on the results, author suggested that to protect the elderly from negative effects of social isolation, we needed the policy to promote elderly's the participation in social activity. The study to analyze the factors related to social isolation was also needed.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.309-316
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• 2020

This study aims to analyze the effect of social exclusion on depression of older adults. In addition, it is to address the mediating effect of social participation and the gender differences on social exclusion-social participation-depression relationship. The researcher conducted a secondary data analysis using the 6^th wave of Korean Longitudinal Study of Ageing. The final sample included 1,925 male and 2,653 female older adults. The results indicated that excluded from work, health, and housing increased depression of male older adults. In the female model, excluded from education also found to be a significant factor predicting depression. Different mediating relationships existed between male and female older adults model and gender differences were also revealed. Based on the findings, the researcher discussed social work implications.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.30.3-31
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• 2010

We performed a comprehensive comparison between GPS Global Ionosphere Map (GIM) and TOPEX/Jason (T-J) TEC data for the periods of 1998~2009 in order to assess the performance of GIM over the global ocean where the GPS ground stations are very sparse. Using the GIM model constructed by CODE at University of Bern, the GIM TEC values were obtained along the T-J satellite orbit at the locations and times of the measurements and then binned into various geophysical conditions for direct comparison with the T-J TECs. On the whole, the GIM model was able to reproduce the spatial and temporal variations of the global ionosphere as well as the seasonal variations. However, the GIM model was not accurate enough to represent the well-known ionospheric structures such as the equatorial anomaly, the Weddell Sea Anomaly, and the longitudinal wave structure. Furthermore, there seems to be a fundamental limitation of the model showing the unexpected negative differences (i.e., GPS < T-J) in the northern high latitude and the southern middle and high latitude regions. The positive relative differences (i.e., GIM > T-J) at night represent the plasmaspheric contribution to GPS TEC, which is maximized, reaching up to 100% of the corresponding T-J TEC values in the early morning sector. In particular, the relative differences decreased with increasing solar activity and this may indicate that the plasmaspheric contribution to the maintenance of the nighttime ionosphere does not increase with solar activity, which is different from what we normally anticipate. Among these results, the plasmaspheric contribution to the ionospheric GPS TEC will be presented in this talk and the rest of it will presented in the companion paper (poster presentation).