• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.118-125
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• 1991

Eighty - eight recently extracted teeth were used to evaluate the leakage characteristics of the following retrofilling materials; amalgam, zinc oxide eugenol cement, glass - ionomer cement, and cermet glass - ionomer cement. Root canals were prepared with step - back method and obturated with gutta percha and zinc oxide eugenol sealer. Root apex were resected 2 mm from apex and class I cavities were prepared with 2 mm or 4 mm depth. The cavities were filled with above materials. After application of varnish on all surface except resected surface, the roots were placed in 1 % methylene blue solution for 6 days. After longitudinal polishing to expose cental parts of filled materials, penetrated depths of dye were measured. The results were as follws. 1. As retrofilling material, glass ionomer cement filling groups showed less leakage than the other groups except zinc oxide eugenol cement filling group(p<0.01). 2. Amalgam filling groups had greater leakage than zinc oxide eugenol cement filling group(p<0.01). 3. 4 mm depth of retrofilled cavity had no effect on leakage characteristics compared with 2 mm depth cavity(p>0.05). 4. Glass ionomer cement and cermet glass ionomer cement filling groups showed less apical leakage than amalgam filling groups. But there was no statistical significance(p>0.05). 5. There was no difference in apical leakage between glass ionomer cement filling groups and cermet glass ionomer cement filling groups(p>0.05).

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.8-14
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• 1999

The flor characteristics around the KRISO 3600TEU container ship model have been experimentally investigated in a subsonic wind tunnel. The mean velocity and turbulence characteristics in the stern and wake regions were measured using an x-type hot-wire probe. The flow characteristics in the stern and near wake regions revealed a complicated three-dimensional flow pattern. The measured results showed clearly the formation of longitudinal vortices and their effect on the flow pattern in the wake region. The shear layer developed along the ship model expands showly to the downward direction. The turbulence statistics measured can be used as comparative data of numerical simulations and provide insights into development of accurate turbulence models for the ship design.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.40-48
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• 1998

Comparative morphology of the genus Branchiostegus has been investigated based on the specimens collected from the adjacent waters of Korea. Branchiostegus japonicus has a distinctive silvery white triangular marking behind eye, while B. albus has nothing. B. albus has about 4 yellow strips along the posterior margin, however, remainder have 5 to 6 longitudinal yellow stripes. In B. auratus, its head length is more than 26% of standard length, but, less than 26% in B. argentatus. This study reveals that B. argentatus is the first record from Korea, and we propose "T$\check{u}$ng-h$\acute{u}$k-ch$\check{o}$m-ok-tu-$\check{o}$" for B. argentatus as a new Korean name.

• Journal of Ocean Engineering and Technology
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• v.15 no.1
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• pp.98-103
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• 2001

This paper is conducted to compare the seismic design standard of a bridge column such as the Korean Bridge Design Standard(KBDS), EC 8, NZS 3101 and ATC 32. The KBDS adopted the seismic design requirements in 1992. The earthquake magnitude in Korea is compared with those in the west coast of the USA. It may be said that the current seismic design requirements of the KBDS provides design results, that are too conservative especially for transverse reinforcement details and amounts in reinforced concrete columns. This fact usually creates construction problems in concrete casting, due to congestion of transverse reinforcement. Furthermore, the effective stiffness; $I_{eff}$ depends on both the axial load P/$A_gF_{ck}$ and the longitudinal reinforcement ratio $A_{st}/A_g, so it is the conservative to use the effective stiffness I$_{eff}$ than the gross section stiffness Ig. Seismic design for the transverse reinforcement content of the concrete column was analyzed and considered to have an extreme-fiber compression strain, response modification factor, axial load and effective stiffness etc.c.

• Earthquakes and Structures
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• v.22 no.4
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• pp.387-399
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• 2022

To study the seismic damage of masonry structures and understand the characteristics of the multi-intensity region, according to the Dujiang weir urbanization of China Wenchuan earthquake, the deterioration of 3991 masonry structures was summarized and statistically analysed. First, the seismic damage of multistory masonry structures in this area was investigated. The primary seismic damage of components was as follows: Damage of walls, openings, joints of longitudinal and transverse walls, windows (lower) walls, and tie columns. Many masonry structures with seismic designs were basically intact. Second, according to the main factors of construction, seismic intensity code levels survey, and influence on the seismic capacity, a vulnerability matrix calculation model was proposed to establish a vulnerability prediction matrix, and a comparative analysis was made based on the empirical seismic damage investigation matrix. The vulnerability prediction matrix was established using the proposed vulnerability matrix calculation model. The fitting relationship between the vulnerability prediction matrix and the actual seismic damage investigation matrix was compared and analysed. The relationship curves of the mean damage index for macrointensity and ground motion parameters were drawn through calculation and analysis, respectively. The numerical analysis was performed based on actual ground motion observation records, and fitting models of PGA, PGV, and MSDI were proposed.

• Journal of Korean Society of Rural Planning
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• v.22 no.1
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• pp.37-48
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• 2016

The purpose of this study is to provide an objective insight for factors that affect people's visiting behavior to educational farms. Second, this study aims to identify the underlying dimensions representing motivations and constraints for visiting educational farms. Third, this study explores differences among the classified groups with respect to structural relationships of each construct. Finally, identifying strategies of educational farm-related organizations could develop to reinforce visit motivations, offset visit constraints and ultimately increase behavioral intention for potential possible visitors to revisit and recommend educational farms. Empirical results of the study suggest implications for promoting the current farm villages and markets with many stakeholders in agricultural industries. Nevertheless, there are some limitations as followed: first, despite the possibility of their effects, the study did not consider other factors, which could affect revisiting behavior such as destination image, experiencing attributes etc. Second, the study needs improvements through longitudinal research because the cross-sectional research could not rule out the alternative explanations. The directions for the future study are as follows: first, future study requires time series approach instead of cross sectional approach. Secondly, future study might utilize comparative study regarding regional characteristics of educational farms or a nation-wide approach. Thirdly, future study can suggest a combined educational farms considering practical educational farm cases. Lastly, it is considered that developing evaluation measures such as quality authentication system will contribute to educational farms' stabilization.

• Korean Journal of Comparative Education
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• v.24 no.5
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• pp.71-95
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• 2014

This is a pilot study of multifaceted longitudinal research project to explore educational experiences of students with multicultural family backgrounds in Korea. Especially for this pilot study, I selected three foreign-born immigrant youths and tried to explore how these youths describe constraints of their learning experience in different culture. The data for this study were mainly collected through qualitative research methods. For a better understanding of the research participants' perceptions in this study, narrative inquiry and series of semi-structured in-depth interviews were conducted for a period of four months which corresponds to one semester of school system in Korea. As a result, this study found that there is an urgent need to establish a systemic and developmentaly appropriate language education programs that ensure educating the language to the foreign-born immigrant youths because their academic achievement, interpersonal relationships, and future depend greatly on the fluency of Korean language. It was also found that it is necessary to take appropriate educational actions in supporting alternative schools where the foreign-born immigrant youths can fully and seriously considered as a whole person. Although this study has some limitations in examining every single aspect of the current state of education of students with multicultural backgrounds in Korea, it provides deep insight into some of their initial educational experiences and proposes several ways to improve these educational programs for them.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.2
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• pp.263-289
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• 2017

New mathematics textbooks for elementary school students are under development according to the 2015 national revised curriculum. Not only contents but also framework of textbooks may be interesting to the mathematics educators and researchers. Considering the high dependency on textbooks in elementary classrooms, the influence of the framework of textbooks in mathematics learning cannot be overlooked. The unit and lesson frameworks of the textbook are important because they are directly related to the quality of mathematic lessons, especially when teachers make a lesson plan based on the unit and lesson frameworks of the textbook. This study is to analyse the unit and lesson frameworks of elementary school mathematics textbooks and to find out elementary school teachers' preference about its analysed key points. For longitudinal analysis, we selected 3rd-grade mathematics textbooks of 5th, 6th, 7th, the 2007, and the 2009 national revised curriculums. For horizontal analysis, we selected 3rd-grade mathematics textbooks of Korea, Japan, United States and Finland. We compared unit and lesson frameworks of various textbooks, and abstracted key elements of the textbook frameworks, and constructed survey questions. Looking at results from survey questions based on analysed key points, we were able to grasp the teachers' preference for unit and lesson frameworks for mathematics textbook. Based on the results of this study, some implications for the development of framework for new mathematics textbooks are suggested.

• Korea journal of population studies
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• v.30 no.2
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• pp.45-69
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• 2007

This study analyzes differences of self-rated health status between Korea and three European countries. Self-rated health status is highly correlated with objective health status such as chronic diseases and ADL(Activities of Daily Living)/IADL(Instrumental Activities of Daily Living), but it is also influenced by individual attitude or belief about health. Therefore, differences of self-rated health status among countries are determined by the combination of (1) differences of objective health status and (2) socio-cultural characteristics affecting individuals' attitude and belief. Using 'Korean Longitudinal Study of Ageing(KLoSA 2006)' and 'Survey of Health, Ageing, and Retirement in Europe (SHARE 2004)', we found that Korean older people are more likely to feel negatively on their health status than their European counterpart. The findings are explained in two different ways. First, how strongly the objective health status affects on the subjective health status varies among countries. Korean older people with chronic diseases are more likely to evaluate their health status negatively because of the diseases than their European counterparts do. Second, after controlling the effects of the objective health condition, the subjective health status of Korean older people is still lower than that of the European elderly.

• Journal of Korean Academy of Nursing
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• v.7 no.1
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• pp.10-19
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• 1977

Trust is an essential factor in human relations, as it enables man to accept and also disclose self. Today's health care demands nursing personnel with high level of trust . This study was designed and carried out in May through June, 1976 to measure the level of trust on nurses through the trust scale of Nurses (75- N) made by Kenneth et al. and the Parent Inventory made by Rake and to provide data for management of nursing personnel. 150 junior nursing students, 164 professional nurses from 5 universities and their medical centers and 55 nurse- educators from 8 baccalaureate nursing programs in Seoul were randomly sampled. Results are as follows : 1. The rank order of the level of trust revealed that nurse educators the highest and nursing students the lowest. 2. The level of trust revealed to be influenced by the relationship with parents at the early stages of life ; Group who appeared to have shared intimacy with their parents were the highest. 3. Factors such as ; number of siblings and birth order among them, religious affiliation, parental presence revealed to have had no influence on the level of trust in all three group. 4. No significant difference were revealed between the group who had put their names down on the questionnaire and the others. 5. Clinical specialities of practice revealed to have no signigicant influence on trust in nurses. 6. Marital status revealed to have significant influence : in nurses and nurse- educators, the mastered re vented to have significantly higher level of trust. (difference by Recommendations : 1. A study on trust level of patients and Nurses in Nurse- patient Relationship. 2. A longitudinal study to investigate the influence of Nursing education on the development of trust in Nurses are recommended. 3. A comparative study on trust level of students of Nursing & non- Nursing major.