• Journal of Conservation Science
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• v.7 no.2
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• pp.60-67
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• 1998

The effects of moisture content (MC) and diffusion period on the diffusion of boron from borate rod through Pinus densiflora and P. koraiensis were investigated as a preliminary research of integrated remedial treatment for heritage wooden structures using borate rod. After equilibrating MCs of samples (15, 25, and 40%), borate rod (1,000 mg) was inserted into the sample, and stored for diffusion of boron at room temperatures ($23^{\circ}C$) for 2, 4, 8, and 12 weeks. Wafers were serially cut at constant intervals from rod treatment point and the boron penetration through longitudinal and transverse direction was measured by staining with boron indicator. For boron diffusion, MC above fiber saturation point was needed, and the diffusion rates increased with time. The fastest rates of diffusion were observed in longitudinal direction, followed by the radial and then the tangential direction. The rates of diffusion in all directions were the fastest in P. koraiensis. In P. densiflora, the diffusion rates through heartwood was faster than that in sapwood in longitudinal direction and vice versa in transverse direction. Based on the best result of this study, optimal space between rod insertion points could be recommended as follows; approximately 120 mm for P. koraiensis and heartwood of P. densiflora, 60 mm for sapwood of P. densiflora in longitudinal direction, and approximately 30 mm for all species tested in transverse direction. However, the effect of rod size and long-term exposure for diffusion on boron movement should be fully investigated for the accurate evaluation of optimal space between rod holes.

• Journal of Conservation Science
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• v.28 no.4
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• pp.353-366
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• 2012

This study was interpreted the making techniques of the Four Guardian Statues in Wanju Songkwangsa Temple, and retained basic data necessary for conservation treatment and restoration of the same material by estimating the soil source. The molding clay used in the Statues showed a variety of material characteristics according to different layers. The first and mid layers estimated as the original molding clay are composed of the same kind of soil. The soil of the finish layer was also confirmed to be genetically similar to that of the first and mid layers, despite little discrepancy. The former restoration layer was inconsistent in material characteristics with the original molding clay in every result of analysis. As a result of gamma radiography, making techniques of the Statues were able to identify the figure of the frame connecting the woods of main pillar frame to sub-frame and steel wire with ㄷ-clamp, nails and straw ropes, and the molding clay constructed upon the frame. Meanwhile, provenance interpretation confirmed that the soil of the estimated provenance area is of the same origin as the soil of the finish layer, and therefore is an appropriate material for conservation treatment. This result will contribute to the research on making techniques of the molding clay Statues.

• Journal of Conservation Science
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• v.28 no.4
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• pp.417-425
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• 2012

Bronze Mirror with fine linear designs in the bronze age shows the greatest alloy and casting skills of the day and presents the highest level of handcrafting and molding techniques. Lately, Lost-wax casting and sand-mould casting were used for the restoration of the national treasures of No. 141 and No. 143 Bronze Mirror with fine linear designs. Also the Principle Component Analysis, Microstructure Analysis, X-ray and SEM-EDS analysis were carried out on the restored Bronze Mirror with fine linear designs. Bronze Mirror that is made of sand-mould casting, hardly has a eutectoid and it is observed as a ${\alpha}$ dendrite. In contrast, Bronze Mirror that is made of lost-wax casting, the eutectoid has found through the ${\alpha}$ dendrite. As we compare lost-wax casting to the sand-mould casting through an analysis of restored Bronze Mirror, mostly, sand-mould casting has better castability and it seems that it brings a clear and equal Bronze Mirror as it has a low cooling rate. In this way, we are able to confirm that there is a big difference between the method by lost-wax casting and by sand-mould casting through an analysis of microstructure and restored Bronze Mirror. If such research will be continued, it will be an opportunity that investigates diverse methods of production techniques.

• Journal of Conservation Science
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• v.34 no.1
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• pp.39-50
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• 2018

This study replicated traditional smelting methods to produce iron blooms from sand iron. The metallurgical properties of the slag and the iron blooms were analyzed. The sand iron materials used in the smelting experiments, which were based on ancient documents, were collected from Gyeong-Ju and Pohang. Analysis by WD-XRF and XRD showed that Gyeong-Ju's sand iron contains a high-titanium, with magnetite, and Pohang's sand iron contains a low-titanium, which magnetite and ilmenite were mixed. Analysis of the slag with XRD, and the micro-structure with metal microscopes and SEM-EDS, confirmed that the major compounds in the slag of the Gyeong-Ju's sand iron were fayalite and $w\ddot{u}stite$, and those in the slag of the Pohang's sand iron were titanomagnetite and fayalite. The differences in the main constituents were confirmed according to the Ti quantity. Finally, we observed the microstructures of the iron blooms. In the case of the iron bloom produced from Gyeong-Ju's sand iron, the outside was found to be dominantly a pearlite of eutectoid steel, while the inside was a hypo-eutectoid steel where ferrite and pearlite were mixed together. While, the major component of the iron bloom produced from Pohang's sand iron was ferrite, which is almost like pure iron. However, there were many impurities inside the iron blooms. Therefore, this experiment confirmed that making ironware required a process that involved removing internal impurities, refining, and welding. It will be an important data to identify the characteristics of iron by-products and the site through traditional iron-making experiments under various conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.478-489
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• 2016

Recently, there has been increasing interest in the remodecycling options of idle spaces around the central city through the urban regeneration. Various studies to create new added value through this way are ongoing. This study aims to analyze the impact relationship and structure on the regeneration of idle space by types affecting the quality of residents' life and local economy revitalization. The hypothesis was verified by a suitability test for setting the hypothesis and statistical significance test from the PLS 3.0 package. The results of this study drew 6 hypotheses from a total of 11 on the 'idle space regeneration of economy based type of PLS-SEM' and 4 hypotheses from a total of 11 on the 'idle space regeneration of neighborhood regeneration type PLS-SEM'. The results can be summarized into several parts. First, if cultural aspects should be considered, the regeneration of idle space (economy-based type and neighborhood-regeneration type) could meet 2 parts, such as the quality of residents' life and local economy revitalization at the same time. Second, improving the 'physical aspects' only affects the 'idle space regeneration of the economy-based type of PLS-SEM'. Third, improving the 'social aspects' only affects the 'idle space regeneration of neighborhood regeneration type of PLS-SEM'. This study has significance in that it provides the empirical analysis for the regeneration of idle space and there are differences according to types of PLS structural model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6036-6045
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• 2014

This survey research was performed to determine the social capital that public officials generate within the relationship of the community at the individual level by performing their public office work as an administrative duty. To this end, a survey was conducted on 500 civil servants in Jeju province. The survey period was May 19-23, 2014. 476 subjects were analyzed using a T-test, One way ANOVA, and multiple regression analysis to on SPSS 19.0Win software. As a result of the analysis, 1. The norms of the community cultural, male staff participation and cooperation, and social capital level of civil servants, showed a significantly higher association than female civil servants. There was a difference between the populations of registration to an association to the work location type. In addition, the social capital increases generally as the level of the officers increases. 2. The sub-category in the social capital of a personal level on civil servants family & associates trust, participation & cooperation and neighbor trust had a positive impact on the efficiency of public services. On the other hand, community cultural associations (network) did not have an influence on efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1090-1099
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• 2013

The purpose of this study was to examine difference in life satisfaction by social activity type in baby boomers. Sampling 1,115 baby boomers, gender and region were assigned. A questionnaire survey was carried out from August to October in 2011. As a result of research, first, the typology of social activity in baby boomers includes 3 groups. The passive social-participation type is the cluster to which 36.8% of the baby boomers belong. They do not join income activity or civic-group activity at all. A case of doing religious activity or family activity includes a minority. There are primarily lots of women and posteriori baby boomers. Academic background level or household income is lower compared to other clusters. The life satisfaction level is moderate. Second, the active social-participation type is the cluster to which 33.8% of the baby boomers belong. They are positive in all the social activities including income activity. What there are lots of women and posteriori baby boomers is similar to the passive social-participation type. However, the academic background or the averagely monthly household income is the highest compared to other clusters. Even the life satisfaction level is the highest. Third, the economic activity orientation type is the cluster to which 29.4% of the baby boomers belong. They participate in income activity, but don't participate in civic-group activity, educational activity, and social activity such as spending time alone. Distribution of priori-and-posteriori baby boomers, distribution of academic background, or monthly household income is moderate level of other clusters. However, unlike other clusters, there are many men. The life satisfaction level is the lowest. Based on result of this study are suggested ways to improve in life satisfaction by social activity type in baby boomers.

• Korea journal of population studies
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• v.32 no.1
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• pp.1-23
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• 2009

This paper uses a survey data to analyze the age-specific fertility rates, age-specific cumulative fertility rates, and ages of marriage of the five birth cohorts of Korean women born in the 1940s and thereafter. It was found that later cohorts reach their highest age-specific fertility rate at higher ages than earlier cohorts. The age-specific cumulative fertility rates of the 1950s and 1960 cohorts were found to be much lower than those of the immediately preceding cohorts, while those of the 1970s and 1980s cohorts were not different from those of the 1960s cohorts. Women belonging to later cohorts were found to get married at relatively higher ages. The estimation results of the hazard model show that women belonging to later cohorts and those with more schooling have a tendency to get married at higher ages. The effect of the birth cohorts is thought to be due to the economic, social, and cultural changes in Korea during the late 50 years or so. The time interval between a woman‘s marriage and first birth was found not to be affected by either the year of marriage or that of her birth. Also, those who remained employed for some time around their marriage and those with low schooling were found to have a lower first child birth hazard, which implies that married women’s employment status and family income play an important role in their decisions on childbirth.

• Journal of Korean Society of Transportation
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• v.15 no.4
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• pp.73-90
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• 1997

The warrants to install traffic signals used in U.S.A. are well specified comparing to those in other countries. Among the eleven warrants of the U.S.A., the Warrant 9, 10, and 11 are especially fit in practice. The warrant relaxed to traffic volumes used presently in Korea have been adopted from the U.S.A. Those may not have been reliable in the traffic situation of Korea. The rules required passing through intersections are not kept well at intersections controlled without signals. The purposes of this study are to test and evaluate the reliability of the Warrant 9 and 11 adopted form U.S.A.n Korean traffic situation and to propose new traffic signal warrants related to traffic volumes fitted in here. The traffic volume warrants are proposed considering the situation of rules not being kept well(current situation) and that of vice versa(ideal situation). The results of this study are following; 1) The total volumes warranted to traffic signals are 1600vph, 1700vph, and 1800vph at 4-legs intersection having 1 by 1 lane, 1 by 2 lanes, and 2 by 2 lanes respectively. The total volumes warranted are 1400vph and 1600vph at 3-legs intersection haying 1 by 2 1anes, and 2 by 2 lanes respectively. 2) Another traffic warrants proposed are transformed from the currant warrants 9 and 11. These warrants are composed of the total volumes and the ratio of the volume of the minor street to that of the major street.

• Education of Primary School Mathematics
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• v.18 no.3
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• pp.235-247
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• 2015

This study analyzed what STEAM elements, except mathematical content, are contained in 2009 revised elementary school 3rd and 4th grade group mathematics textbooks. STEAM elements in the textbooks were examined by grade and by content area in the elementary school mathematics curriculum. According to the results, the difference between 3rd and 4th grade in the number of STEAM elements is almost not visible. Distribution of specific content areas could be seen that the distribution STEAM element is similar to the percentage distribution of the content area. However, the number of STEAM elements are different depending on the type of STEAM. The number of arts element is 448(67.6%) and this elements are seen the most. The number of representative art and cultural art is 344(51.9%) and 104(15.7%), respectively. The number of technology-engineering and science is 160(24.1%) and 55(8.3%), respectively. We need to developed to promote use of science element in next mathematics curriculum.