• Korean Journal of Health Education and Promotion
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• v.26 no.5
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• pp.1-13
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• 2009

Objectives: The purpose of this study was to examine factors influencing stress coping behaviors of elementary students in Korea. Methods: This study used a descriptive comparative survey design. A total of 1,161 elementary students voluntarily participated in the study from 10 schools at three regional levels (large and medium-sized cities, and rural towns). Coping behaviors were measured by the modified Ways of Coping Checklist. The data were analyzed using descriptive statistics, t-test, ANOVA, and multiple regression. Results: The most commonly used stress coping behavior reported by the participants was mystic coping, followed by positive coping, and negative coping. Students living in the large city and female students tended to use more coping behaviors than students living in the medium-sized city or rural towns and male students, respectively. Positive coping behaviors were associated with high school performance while myotic coping behaviors were associated high life satisfaction. Conclusion: Elementary students who are males, dissatisfied with their lives, or living in large cities or rural towns tended to be at risk for poor coping. There were differences in factors influencing coping behaviors by type of coping behaviors. An approach to building a successful coping behavior that is specifically tailored to the gender subsets of population and region-specific social and physical environment is recommended.

• Journal of the Korean Home Economics Association
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• v.39 no.11
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• pp.129-144
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• 2001

In spite of rapid sociocultural changes and an increase in the number of nuclear families in recent years, quite many families in Korea still have taken the extended family form where daughter-in-law provides care for the elderly parents. Even though the nature of the inter-generational relationship in Korea is reciprocal in many regards, most of the studies looked at the burden or costs of coresidence with the elderly parents while relatively little attention has been given to the positive side of the coresidence. This study is an attempt to fill this gap in the area. The purpose of this study is to examine not only the costs but also benefits of the coresidence with the elderly parents. We also explore whether there is a rural-urban differences in costs and benefits of coresidence and related factors. For the purpose, data were gathered from 876 daughters-in-law of three generational family both in rural and urban area, using structured questionnaire. The statistical methods used for data analysis were descriptive statistics, cross tables, and regression analysis with SPSS/PC+ program. The major findings of this study were as follows: Marital and economic status of the elderly parents, age, job status and filial responsibility attitude of caregiver, sibling support, and coresidence duration were the significant variables predicting the level of perceived benefits. Marital status of elderly parents, income, job status, educational level, and filial responsibility altitude of caregiver, residence region affected the level of perceived costs. Rural-urban differences are found in many aspects of coresidence experiences and related factors. Rural caregivers receive higher level of the sibling support, have more traditional final responsibility altitude and perceived less costs and more benefit than urban caregivers. There also are differences in the factors influencing the level of perceived costs and benefits between rural and urban area. Level of sibling support and final responsibility attitude have significant impact on both the perceived costs and benefits. But there are differences in terms of that perceived costs and benefits of urban caregivers are affected by job status of caregivers while those of rural caregivers are affected by educational level of caregivers and marital status of elderly. The results confirm that Korean caregivers experience both positive and negative aspects of coresidence and shows that the nature of the inter-generational relationships differ between rural and urban Korea.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.63-67
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• 2016

In this paper, we present an indirect method of elastic modulus measurement for various lamination layers formed on polymer-based compliant substrates. Although the elastic modulus of every component is crucial for mechanically reliable microelectronic devices, it is difficult to accurately measure the film properties because the lamination layers are hardly detached from the substrate. In order to resolve the problem, 3-point bending test is conducted with a film-substrate specimen and area transformation rule is applied to the cross-sectional area of the film region. With known substrate modulus, a modulus ratio between the film and the substrate is calculated using bending stiffness of the multilayered specimen obtained from the 3-point bending test. This method is verified using electroplated copper specimens with two types of film-substrate structure; double-sided film and single sided film. Also, common dielectric layers, prepreg (PPG) and dry film solder resist (DF SR), are measured with the double-sided specimen type. The results of copper (110.3 GPa), PPG (22.3 GPa), DF SR (5.0 GPa) were measured with high precision.

• KSBB Journal
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• v.10 no.3
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• pp.241-248
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• 1995

For the treatment of poorly biodegradable polyvinyl alcohol(PVA) in dye-processing wastewater, immobilized microbial beads were prepared by uslng agar-acrylamide method. PVA removal efficiency for the synthetic wastewater was 85% at the PVA volume loading rate of $3.1g/\ell$.day. In case of real desizing wastewater, PVA removal efficiency was 81.3% at the PVA volume loading rate of $3.25g/\ell$.day. In observation of cross section of immobilized bead passed 5 months with diameter of 2.4mm, the growth of cell was limited by the resistance of substrate and oxygen transfer for the inners region of more than 48% of bead radius from the surface. It was estimated that 70% of total removed PVA was degraded by the immobilized cells in the continuous immobilized reactor. Substrate utilization rate in the suspended reactor was decreased with increasing dilution rates above 0.083 hr-1, but that in the immobilized reactor was increased with increasing dilution rates up to 0.125hr-1. The substrate removal efficiency of immobilized reactor was much superior to that of suspended reactor with increasing dilution rates. Saturation constant of substrate utilization rate equation, Ks was $6.6 g PVA/\ell$, and maximum specific substrate utilization. k was 0.175g PVA/g cell.hr

• Journal of Sensor Science and Technology
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• v.5 no.5
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• pp.21-29
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• 1996

A piezoresistive silicon acceleration sensor with 8 beams, utilized by an unique silicon micromachining technique using porous silicon etching method which was fabricated on the selectively diffused (111)-oriented $n/n^{+}/n$ silicon subtrates. The width, length, and thickness of the beam was $100\;{\mu}m$, $500\;{\mu}m$, and $7\;{\mu}m$, respectively, and the diameter of the mass paddle (the region suspended by the eight beams) was 1.4 mm. The seismic mass on the mass paddle was formed about 2 mg so as to measure accelerations of the range of 50g for automotive applications. For the formation of the mass, the solder mass was loaded on the mass paddle by dispensing Pb/Sn/Ag solder paste. After the solder paste is deposited, Heat treatment was carried out on the 3-zone reflow equipment. The decay time of the output signal to impulse excitation of the fabricated sensor was observed for approximately 30 ms. The sensitivity measured through summing circuit was 2.9 mV/g and the nonlinearity of the sensor was less than 2% of the full scale output. The output deviation of each bridge was ${\pm}4%$. The cross-axis sensitivity was within 4% and the resonant frequency was found to be 2.15 KHz from the FEM simulation results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3006-3013
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• 2015

Flat tube heat exchangers can improve the thermal performance significantly compared with round tube heat exchangers. For proper design of flat tube heat exchangers, one should know the tubeside heat transfer coefficients. In this study, convective boiling heat transfer coefficients of R-410A were obtained in a flat extruded aluminum tube with $D_h=1.41mm$. The test range covered mass flux from 200 to $600kg/m^2s$, heat flux from 5 to $15kW/m^2$ and saturation temperature from $5^{\circ}C$ to $15^{\circ}C$. The heat transfer coefficient curve shows a decreasing trend after a certain quality(critical quality). The critical quality decreases as the heat flux increases, and as the mass flux decreases. The early dryout at a high heat flux results in a unique 'cross-over' of the heat transfer coefficient curves. The heat transfer coefficient increases as the mass flux increases. At a low quality region, however, the effect of mass flux is not prominent. The heat transfer coefficient increases as the saturation temperature increases. The effect of saturation temperature, however, diminishes as the heat flux decreases. Both the Shah and the Kaew-On et al. correlations reasonably predicted the present data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.280-288
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• 2016

This study proposes improved welding tools for magnesium alloys. Two types of tools were used for friction stir welding (FSW). The effect of the welding tools on the FSW joints was investigated with a fixed welding speed of 200mm/min and various rotation speeds of 400 to 800 rpm. After FSW, the joints were cross-sectioned perpendicular to the welding direction to investigate the defects. A tensile test and Vickers hardness test were conducted to identity the mechanical properties of the joints. Defects were observed when the rotation speed was 400 rpm, regardless of the welding tool, and the amount of defects tended to decrease with increases in rotational speed. Defect-free welds were obtained when the rotation speed was 800 rpm. The best weld quality was acquired using the C type welding tool. The rotation speed of 800 rpm and welding speed of 200 mm/min produced the best joining properties. The ultimate tensile strength, yield strength, and elongation of the welded region were 90.0%, 69.1%, and 83.2% those of the base metal, respectively.

• Korean Journal of Remote Sensing
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• v.14 no.4
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• pp.325-342
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• 1998

Two RADARSAT SAR images with different modes acquired by Canadian Space Agency to test the effectiveness of geological lineament extraction and spring water detection over the Cheju Island. Geological lineaments are poorly developed this basalt dominant volcanic island, but more linear features can be extracted when SAR and TM images are simultaneously analyzed than when TM image alone is used. This results mainly owe to the facts that RADARSAT SAR systems are able to provide data with different frequencies, azimuth, and incidence angles. Distribution of spring water along coast is poorly correlated with geological lineaments or drainage pattern, but those in middle range of mountain region are developed along geological lineaments. Detection of spring water using remotely sensed images are turned out to be very difficult to achieve. Radial shaped sea surface temperature anomaly derived from TM thermal band should be the best candidate for spring water, but the resolution is not high enough. We also investigate the normalized radar cross section (or sigma naught) converted from RADARSAT and ERS-1 SAR data but to discriminate the spring water effectively except where relatively large water mass is observed on land side. Speckle noise and irregularity in physical sea surface condition are the serious obstacles for this application. ERS-1 SAR image acquired in low incidence angle was more useful for geological lineament estimation and water body study than RADARSAT SAR images with high incidence angles. Therefore the selection of incidence angle is critical in geological and spring water applications of SAR images, and low incidence angles less than about 30$^{\circ}$ are recommended to monitor the Cheju volcanic island.

• Korean Journal of Comparative Education
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• v.27 no.3
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• pp.23-48
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• 2017

The purpose of this study is to analyze the meaning of Joseon school or Korean school (hereafter, Korean school) education in the context of Japanese foreign education through oral history of Korean residents in Japan. I focused on how educational experience of Korean residents who were born and raised in Japan formed through the Korean school education was implemented and applied in Japanese society. Participants were 7 Korean residents in Japan who were educated at Korean school. They all grew up in Kansai region including Osaka Prefecture and Hyogo Prefecture. The oral data was collected three times from September 17, 2014 to February 29, 2016. The oral interviews were conducted two times, two hours per session. As to the analysis of oral data, we first prepared the classification table according to the detailed themes and then cross-checked between the history of Korean residents in Japan as well as related literatures and the memories of the oral interviewees. The results of this study are as follows. The oral interviewees recognized that there was no relation between the development process of foreign education policy in Japan and Korean school education. They said that the education of foreigners in Japan was "consistent with the exclusion of Korean schools." However, unlike the Japanese central government, local governments implemented the policies such as providing subsidies to Korean schools, accepting the graduates of Korean schools in public and private universities, and providing fare discounts for students of Korean schools in local private railways.

• Journal of Korea Port Economic Association
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• v.34 no.3
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• pp.93-112
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• 2018

The purpose of this study is to analyze the flow of e-commerce freight transported by maritime transportation for China and to identify the characteristics of cargo by region/item for finding the ways to promote e-commerce export to China. Thus, this study analyzed the e-commerce export and import data on cargo moved via maritime transportation between Korea and China from 2015 to 1Q18, using Origin-Destination(OD) analysis and visualization techniques. The results indicated that the largest number of Chinese e-commerce cargoes were imported at Incheon Port, which has a clearance facility for e-commerce cargo. In the case of Pyeongtaek Port, e-commerce cargo imported from China has transported to Incheon Customs again, causing the inefficiency through the customs clearance process. Unlike the case of e-commerce imports where the final destination is distributed nationwide, e-commerce products exported to China through maritime transportation were found to be mainly confined to Seoul and Gyeonggi provinces, where freight forwarding companies and forwarders are concentrated. In addition, unlike e-commerce import cargoes, e-commerce items exported through maritime transportation were mainly confined to clothing and cosmetics, and export volume was also less than imports. This study provides some possible strategies to increase the volume of freight and to attract export products as follows: i) to diversify products exported to China through e-commerce transshipment, ii) to diversify export items by building the cold chain in e-commerce transport with China.