• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.851-868
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• 2015

A radio telescope which has been dominantly used for millimeter and submillimeter wave radio astronomy is a cassegrain antenna. A various receivers with specified observing bandwidths are installed on cassegrain antenna so as to carry out to investigate a diverse radio astronomy. A beam guiding system should be required so that a various receiver can be conducted their own observational frequency bands. The beam guiding system based on Gaussian beam transmission theory consists of quasi-optical circuit used such ellipsoidal mirror, dielectric lens and feed horn. In this paper, not only Gaussian beam transformations based on Gaussian beam theory are presented, but also design techniques for quasi-optical circuit are given. By using proposed design techniques, both Gaussian beam quasi-optical circuits to be used for cassegrain antenna and design results are also described. Properties of key focusing elements such ellipsoidal mirror and dielectric lens and feed horn are also discussed. It is expected that beam guiding system to be applied cassegrain antenna could be easily designed by using proposed design techniques.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.951-953
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• 2015

Learning for thinking says the behavior of the organism changes as a result of practice or experience. It is very difficult to identify focusing ability objectively when students study. But, brain of the body is not so. EEG signal means continuously electric records of brain potential variation between two points on the scalp when brain activities take place. In types of EEG, there are delta(0~4Hz), theta(4~8Hz), alpha(8~13Hz), beta(13~30Hz) and gamma waves(30~50Hz). SMR waves and Mid-beta waves appear when focused for studying. Part for the most influence on concentrating reported that Mid-beta waves. In relation to brain activities, EEG has been actively researched for evaluating brain focus index system during learning and study. So, By using Biopac system for this study, measured brain wave was converted into FFT for extracting Mid-beta domain signals that are related to learning after giving focus invoked subjects to a small number of people. When concentrating, we measured the change in the power of the Mid-beta frequency domain and presented a correlation. Based on these results, we analyzed whether students are concentrated objectively on learning or not. and hope to offer more efficient learning method.

• Journal of Life Science
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• v.22 no.5
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• pp.613-620
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• 2012

To evaluate the effects of sleep habits on the powers of beta waves and the sensory motor rhythm of the electroencephalogram (EEG), female college student subjects were divided into four groups, according to their sleep habits, as follows: GSHG (Good Sleep Habit Group), CSHG (Common Sleep Habit Group: late bedtime), CSDG (Cognitive Sleep Disorder-Delayed Sleep Phase Syndrome Group), and NSDG (Non-cognitive Sleep Disorder-Delayed Sleep Phase Syndrome Group). Brain function was stimulated by reading a book for 3 min in the morning (9~12 am) and the EEG was measured. According to the results, the powers of the beta waves and sensory motor rhythm were not different during the resting period among the four groups. However, during the reading stimulation period, the powers of beta waves and the sensory motor rhythm in the GSHG were significantly greater than in the other groups ($p$ <0.05). Beta powers during stimulation also increased in all brain areas in the GSHG ($p$ <0.05). Interestingly, these were decreased in the frontal and temporal lobes in the CSHG by the reading stimulation ($p$ <0.05). On the other hand, sensory motor rhythm, which represents focusing efficacy, only improved in the GSHG. These results indicate that the brain's focusing function during the reading stimulation was not properly operating in the morning in the female college students who had a delayed bedtime and bad sleep habits.

• Cross-Cultural Studies
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• v.43
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• pp.405-428
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• 2016

The purpose of this paper is to examine the narrative-building method and the post-historical descriptive aspects of the movie Paradise in Service, which deals with the modern history of Taiwan. Although Paradise in Service tells the history of a certain time period, it focuses on the anguish and agony felt by people who lived during that age rather than on the meaning of historical events or interpretation of the past in terms of official historical discourse. That is, as it avoids looking at the present by composing a narrative in the descriptive historical context and from bearing weight from the viewpoint of realism, it gains the possibility of establishing a new field of discourse through a post-historical discussion using descriptive historical texts. However, the movie tries to create fantasy through a special type of licensed prostitution as a means of post-historical description. In other words, when this movie tries to reproduce the microscopic history of common people in trouble because of a historical tragedy, it considers only men and excludes "weak" women. Thus, although Paradise in Service has meaning in that it gives an example of how movies can disrupt official historical discourse and group memory and rewrite history by focusing on individuals, it is limited by its male-centrism.

• Korean Journal of Social Welfare
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• v.69 no.1
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• pp.59-77
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• 2017

The purpose of this study is to understand Korean women in later life by identifying the relationships between providing care for grandchildren and the health of women who aged above 50 years old. Focusing on the longitudinal patterns of providing care of grandchildren and physical and psychological health, this study used data from the second, third, fourth, and fifth waves of Korean Retirement and Income Study(KReIS) and regression to analyze the data. The following results were found. First, women who stopped providing care for grandchildren were more likely to have higher physical health status in later life than those who providing no care between the second wave to the fourth wave of the KReIS(p < .05). In addition, women who have continuously provided care for grandchildren were more likely to have lower physical health status at marginally significant level. However, there is no significant relationship between providing care for grandchildren and women's psychological health status. The findings of this study suggest that there are the different findings for the relationships between providing care for grandchildren and physical health status and psychological health status based on the longitudinal patterns of providing care of grandchildren. Lastly this paper discusses implications for future researcher and social welfare practitioners.

• Journal of the Korean Home Economics Association
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• v.43 no.6 s.208
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• pp.113-131
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• 2005

The purpose of this study was to investigate older people's planning for estate distribution by examining the factors associated with their will-holding status. This study used data from the 1994 Assets and Health Dynamics among the Oldest Old (AHEAD) Survey, Wave One. The objectives of this study were (a) to establish profiles of older people who have a written will and to compare their financial portfolios across will-holding status; (b) to identify factors that influence the decision to make a will, and (c) to draw implications for family economists, financial educators, planners, and policy makers. The results suggested that a household's financial resources (i.e., liquid and illiquid assets, housing equity, and household income) positively influence the probability of having a will. Older people who resided in a community property state and who were in poor health were less likely to be will-holders than their counterparts, holding financial resources and other variables constant. Demographic characteristics such as age, education, and race, and behavioral characteristic also were significant determinants of the likelihood of having a will. Volunteer participation and charitable contribution, which are proxies for altruism, increased the likelihood of having a will. The probability of having a will also was higher among those who had life insurance and had gwen inter-vivos gifts of more than $\$5,000$ to their children or grandchildren in the past 10 years. On the other hand, the likelihood of having a will declined with increasing number of biological children. From the findings, implications for financial planners and educators were suggested along with directions for future research.

• The Journal of Engineering Geology
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• v.12 no.4
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• pp.405-419
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• 2002

Fracture roughness of rock specimens is observed by a new confocal laser scanning microscope (CLSM; Olympus OLS1100). The wave length of laser is 488 nm, and the laser scanning is managed by a light polarization method using two galvano-meter scanner mirrors. The function of laser reflection auto-focusing enables us to measure line data fast and precisely. The system improves resolution in the light axis (namely z) direction because of the confocal optics. Using the CLSM, it is Possible to measure a specimen of the size up to $10{\;}{\times}{\;}10{\;}cm$ which is fixed on a specially designed stage. A sampling is managed in a spacing $2.5{\;}\mu\textrm{m}$ along x and y directions. The highest measurement resolution of z direction is $10{\;}\mu\textrm{m}$, which is more accurate than other methods. Core specimens of coarse and fine grained granite are provided. Fractures are artificially maneuvered by a Brazilian test method. Measurements are performed along three scan lines on each fracture surface. The measured data are represented as 2-D and 3-D digital images showing detailed features of roughness. Line profiles of the coarse granites represent more frequent change of undulation than those of the fine granite. Spectral analyses by the fast Fourier transform (FFT) are performed to characterize the roughness data quantitatively and to identify influential frequency of roughness. The FFT results suggest that a specimen loaded by large and low frequency energy tends to have high values of undulation change and large wave length of fracture roughness.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.724-729
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• 2008

In the case of 'MAEMI', the Typhoon which formed in September, 2003, the largest-scale damage of tidal wave was caused by the co-occurrence of Typhoon surge and full tide. Until now Korea has been focusing on the calculating the amount of damage and its restoration to cope with these sea and harbor disasters. It is essential to establish some systematic counterplans to diminish such damages of large-scale tidal invasion on coastal lowlands considering the recent weather conditions of growing scale of typhoons. Therefore, the purpose of this research is to make the counterplans for prevention against disasters fulfilled effectively based on the data conducted by comparing and analyzing the accuracy between observation values and the results of estimating the greatest overflow area according to abnormal tidal levels centered on Masan area where there was the severest damage from tidal wave at that time. It's necessary utilize data like high-resolution satellite image and LiDAR(etc.) for correct analysis data considering geographical characteristics of dangerous area from the storm surge. And we must make a solution to minimize the damage by making data of dangerous section of flood into GIS Database using those data (as stated above) and drawing correcter damage function.

• Korean Journal of Family Social Work
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• no.53
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• pp.161-198
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• 2016

This study examined how previous financial and time transfers from mothers to their adult children affect co-residence of elderly mothers and their adult children in South Korea. This study employed multi-level logistic analysis considering hierarchical relationship structures between mothers and their adult children. A sample of 1,925 elderly mothers and 7,460 adult children was extracted from data which were from the first wave (in 2006) to the forth wave (in 2012) of Korean Longitudinal Study of Ageing (KLoSA). The result of the analysis suggested that past financial transfer from mothers to their adult children was not significantly associated with co-residence between elderly mothers and their adult children. However, likelihood of co-residence increased with the amount of time transfer, which was measured by unit of time for elderly mothers' caring for their grandchildren. This study discussed that long-term reciprocal relationships between elderly mothers and their adult children are built by intergenerational support relationships. However, the result that showed only grandmaternal child care affected intergenerational co-residence implies that intergenerational care may play an important role in intergenerational reciprocal relationships. Through these findings, this study suggested theoretical, practical, and policy implications.

• Korean Journal of Social Welfare Studies
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• v.47 no.1
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• pp.261-290
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• 2016

The purpose of this study was to examine how previous grandmaternal child care affects contacts between older mothers and their adult children. This study especially focused on intergenerational long-term reciprocity relationships. In this study, data from the first wave (in 2006) to the forth wave (in 2012) of Korean Longitudinal Study of Ageing yielded a sample of 1,925 elderly mothers and 7,460 adult children. This study employed multi-level analyses considering hierarchical structures between the mothers and their adult children. In this study, past grandmaternal child care was measured by providing care behavior and unit of time for care. Intergenerational contacts was measured by frequency of face-to-face and non-face-to-face contacts. The results showed that adult children who previously received child care from their mothers were more likely to contact to their mothers. Additionally, the increasing amount of time for elderly mothers to provide care to their grandchildren led to more frequent contacts between elderly mothers and their adult children. The findings proved that grandmaternal child care was in important position in reciprocal relationships between elderly mothers and their adult children. Through these results, this study suggested theoretical, policy, and practical implications.