• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.210-217
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• 2016

Purpose: The aim of this study was to evaluate the marginal and internal adaptation of monolithic zirconia restoration made without physical model by digital intraoral scanner. Materials and methods: A prospective clinical trial was performed on 11 restorations as a pilot study. The monolithic zirconia restorations were fabricated after digital intraoral impression taking by intraoral scanner (TRIOS, 3shape, Copenhagen, Denmark), computer-aided designing, and milling manufacturing process. Completed zirconia crowns were tried in the patients' mouth and a replica technique was used to acquire the crown-abutment replica. The absolute marginal discrepancy, marginal gap, and internal gap of axial, line angle, and occlusal part were measured after sectioning the replica in the mesiodistal and buccolingual direction. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U test (${\alpha}=.05$). Results: From the adaptation analysis by replica, the statistically significant difference was not found between mesiodistal and buccolingual sections (P>.05), but there was significant difference among the measurement location (P<.01). The amount of absolute marginal discrepancy was larger than those of marginal gap and internal gap (P<.01). Conclusion: Within the limitations of this study, the adaptation accuracy of model-free monolithic zirconia restoration fabricated by intraoral scanner exhibited clinically acceptable result. However, the margin of zirconia crown showed tendency of overcontour and cautious clinical application and follow up is necessary.

• Journal of Periodontal and Implant Science
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• v.47 no.5
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• pp.312-327
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• 2017

Purpose: This study assessed marginal bone remodeling and soft tissue esthetics after the loading of single bone-level implants in the anterior maxilla. Methods: An open, single-arm observational clinical trial with 3 years of follow-up was performed, including 22 implants. The patients presented with a single tooth gap in the anterior maxilla (tooth positions 14-24), with natural or restored adjacent teeth. An implant was placed at least 8 weeks post-extraction and healed submerged for 6 weeks. After the second-stage operation, a fixed provisional prosthesis was provided. The final restoration was placed 6 months after the provisional restoration. The time of the provisional crown connection was considered to be the baseline in this study. Esthetic parameters and the marginal bone level were assessed at 6, 12, 24, and 36 months. Results: All implants were well integrated in the bone. A statistically significant increase was found in the mean implant stability quotient between the time of the provisional prosthesis and the time of the final prosthesis. Most implants (95.5%) revealed marginal bone resorption (<0.5 mm), and just 1 implant (4.5%) showed a change of 2.12 mm from baseline to 36 months (mean $0.07{\pm}0.48mm$), while the crestal bone level decreased significantly, from $2.34{\pm}0.93mm$ at baseline to $1.70{\pm}1.10mm$ at 36 months. The facial gingival margin and papilla were stable and the esthetic scores indicated high patient and dentist satisfaction. Conclusions: Platform-switching bone-level implants placed in maxillary single-tooth gaps resulted in successful osseointegration with minimal marginal bone resorption. The peri-implant soft tissue was also esthetically satisfying and stable.

• Journal of Venture Innovation
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• v.1 no.2
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• pp.141-156
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• 2018

The average life expectancy in Korea was 62.3 in 1970 and 82.3 in 2016, which increased by more than 20 years and it's expected to enter super-aged society after passing through the aged society. The poverty, loneliness, inactivity, and disease which were called as four problems of senior citizens have become social issues. Thus, the project for creating job opportunities for the elderly(Project supporting social activity of seniors) was carried out as the senior welfare policy. First purpose was to help the elderly engage in society actively, make their income and build up health while preventing the problems of the aged and reducing social cost as well. The second purpose was to help them live healthy later lives through various jobs. This study aimed to investigate whether the project for creating job opportunities for the elderly increased quality of later lives through health promotion and healthy later lives while engaging in the society, rather than making income according to its purpose, by conducting the survey before and after participating in the project for creating job opportunities for the elderly. It's expected to see this study could contribute to making more opportunities for the senior citizens to engage in the society continuously, rater than making money.

• Journal of Korean Society of Forest Science
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• v.68 no.1
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• pp.37-45
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• 1985

The second year's results of surface fire effects on forest vegetation and soil properties and fire tolerance of various tree species were investigated in Mt. Gwanak, Kyunggi-do, successively after the study of the first year's effect in the same place. Soil moisture contents, organic matters, and most of soil nutrients including exchangeable bases had increased just after fire and went down to become somewhat constant. Available phosphorous at fired area decreased until it became similar to that at unfired area, while pH of subsoil was continuously increasing from just after fire till after 1 year. For Lespedeza and Weigela species, fire tolerance of tree crown was the lowest but reproductive capacity was the highest. And both of them were high for Rhododendron species. More exact classification into Increasers, Decreasers, Invaders and Neutral species was possible in the second year's study. According to comparison of similarities, it was found that the vegetational structure at fired area is slowly restoring to original state as time goes.

• Korean Journal of Community Nutrition
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• v.13 no.5
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• pp.682-692
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• 2008

The purpose of this study was to investigate the status of children's breakfast skipping and their mothers' needs for breakfast service at child care centers. A survey was conducted with mothers of children aged 3 to 5 years and attending child care centers in Gwanak-gu, Seoul. Out of 960 questionnaires distributed to the caregivers at 32 child care centers, 633 were returned (66% response rate), and 449 were analyzed (47% analysis rate) after excluding data from the respondents not meeting the selection criteria for this study: mothers of children aged 3 to 5 years. Over 2/3 (69%) of children ate breakfast every weekday (Breakfast Eaters) and almost 1/3 (31%) of children skipped breakfast one time or more often on weekdays (Breakfast Skippers). The collected data were compared between Breakfast Eaters and Breakfast Skippers. The average Good Dietary Practice Score of Breakfast Skippers was significantly lower than that of Breakfast Eaters, implying poorer dietary habits. A higher percentage of mothers of Breakfast Skippers (62%) responded that breakfast service was 'necessary' or 'very necessary' at child care centers than those of Breakfast Eaters (27%). A multiple logistic regression analysis was conducted to determine factors affecting mothers' needs for breakfast service at child care centers. The result showed that the children's ages, mothers' occupational status, household monthly income, frequencies of eating breakfast on weekdays and satisfaction level with morning snack provided at child care centers affected mothers' needs for breakfast service at child care centers. In particular, mothers who had a full-time job (OR = 2.06) than housewives, mothers whose children did not eat breakfast at al (OR = 3.54), ate $1{\sim}2$ times (OR = 5.50) or ate $3{\sim}4$ times (OR = 3.80) on weekdays than those whose children ate breakfast every weekday were more likely to have needs for breakfast service at child care centers than housewives. In conclusion, Breakfast Skippers tended to have poorer dietary habits than Breakfast Eaters and Full-time working mothers had higher needs for breakfast service at child care centers. This study results suggest that child care centers consider serving breakfast to children as the number of working mothers increases.

• Korean Journal of Environment and Ecology
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• v.24 no.5
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• pp.575-581
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• 2010

This study was accomplished for verifying the biotope field survey accuracy in the forests. Biotope data is used as the standard for the preservation and restoration of the urban ecosystem. The study area is the forests of Gwanak-gu, Seoul. For verifying accuracy, first we compared biotope field survey results between 2000 and 2005, second we compared between field survey results and satellite imagery. For comparing with satellite imagery, we delineated the evergreen-coniferous forests from imagery taken during winter season. As a result of comparison, the ratio of most actual vegetation types by delineated detail field surveys were matched around 92% between 2000 and 2005. But, between 2 field surveys, around 60% of total vegetation type was regionally matched. Evergreen-coniferous forests extracted by satellite imagery were regionally matched 69.4% of field survey result in 2000, and matched 80% of the result in 2005. If we consider the delineating errors from deciphering the picture, the results have high accuracy, especially 2005. The processes of verifying accuracy have not been proceeding in the part of delineating actual vegetation works. The verification of accuracy is important for the renewal process. Thus, the various verification methods will be studied and criteria should be developed for enhancing objectivity.

• Journal of Korean Society of Rural Planning
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• v.20 no.2
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• pp.71-80
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• 2014

This study intended for Cheongryongsan Community Garden in Gwanak-gu, one of the demonstration places for 'Community Garden' Project recently implemented by the Seoul Government. This study had two major purposes: investigating the current status of the management and usage and identifying its characteristics; investigating users' awareness to consider the construction and operation directions of sustainable community gardens. This study was conducted based on several surveys such as an investigation into the spatial configuration and the management system of parks through a field study, a use survey through a questionnaire survey for vegetable garden users and an awareness survey about the construction direction of gardens direction preferred by users through the analytical hierarchy process (AHP). As a result of a questionnaire survey for vegetable garden users, the usage status was summarized as follows: Considering the common trends in the 2012 and the 2013 user survey, women used Cheongryongsan Vegetable Garden more than men. Over fifties used it most of all users. Users were mostly neighborhood residents. They used to visit there three to five times a week and stayed for about 30 minutes to one hour. Users differently responded to the question related to the order of priority for the use of the garden in the 2012 and the 2013 survey. They had increasingly used it for individuals' production activities more than social exchanges. As a result of making an AHP analysis for general park users, vegetable garden users there were clear differences in the targets which each subject put emphasis on in relation to the construction and operation of vegetable gardens. General park users recognized a vegetable garden as a park where park functions and the functions of the vegetable garden coexisted. On the other hand, vegetable garden users viewed it as a space where they attached importance to the functions of the vegetable garden like an allotment. Last, this study contemplated subjects related to the construction and operation of vegetable gardens which had to be considered in the future. Vegetable gardens tended to be biased as personal hobby places. It was viewed that the main reason was insufficient support activities for vegetable garden education and exchange programs originally planned when vegetable gardens had been constructed. Vegetable garden users recognized vegetable gardens as places for individuals' farming activities like allotments. For the desirable operation of vegetable gardens, it would be necessary to give priority to the park management before the production activities in individuals' vegetable gardens. The important role of the government would be to build the base through the provision of education and opportunities so that a local resident organization could actively participate in the management of a vegetable garden after a vegetable garden was constructed. It would be necessary to make a use survey and an awareness survey for users conducted in this study on a regular basis because the surveys could be important basic data in the decision-making process for the sustainable operations of the vegetable garden.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.532-541
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• 2016

The National Environmental Specimen Bank (NESB) has been collecting broad leave samples to monitor environmental pollution from five different designated sampling areas. In order to ensure the reproducibility and comparability of the results, all the procedures from selecting trees and pooling leaves to make the representative sample are defined in the standard operation procedures(the SOP). The representative samples were subjected to the chemical analyses for some heavy minerals and Polycyclic Aromatic Hydrocarbons(PAHs). The uncertainty levels involved in each step of the SOP, that is, the sampling and the chemical analysis, were derived using the Robust ANOVA, which enables the relative comparison among the different levels of pollutants concentrations with confidence. Furthermore, the effect of the varying degrees of precipitation on the pollutants concentration of the leaves was also examined. Overall, the biological difference estimated from the duplicate samples was found to exceed the variation across the site, implying even aerial deposition over site. Samples from Gwanak Mt. showed highest heavy metal concentrations than the other sites. Washing off effect of the pollutants adhering in the form of particles on the leaf surface was found to be affected by the cumulative precipitation.

• Journal of Elementary Mathematics Education in Korea
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• v.18 no.2
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• pp.357-377
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• 2014

The purpose of this study is to identify whether math class with clip-type contents has a significant impacts on the academic achievement and attitude of students. To answer the questions, two classes of 4th graders at Sinlim Elementary School in Gwanak-gu, Seoul were selected as subjects; they were divided into experimental group and comparative group. They were confirmed as a homogeneous group at the significance level of 0.05 during a pre-test. The findings are as follows. First, math class with clip-type contents had positive influence on the academic achievement. Second, math class with clip-type contents had positive influence on the attitude towards learning. Furthermore, proper clip-type contents for class boost their understanding and enhance their mathematical thinking with multiple views. It led to their self-confidence in learning math, developing a positive attitude towards math. The benefits of the present research can be summarized as follows. First, the math class with clip-type contents benefited both teachers and students. For teachers, it helped them boost the quality of their teaching. For students, it helped them understand the class better, improving their academic achievement. Second, the diverse, interesting contents had a positive impact on the following of the students: self-concept of math; attitude towards math; learning habits.

• Anxiety and mood
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• v.7 no.2
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• pp.73-78
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• 2011

Objectives : This study examined drinking habits, anxiety, and impulsiveness in employed women. Methods : We sampled 925 residents aged over 20 years in Gwanak-gu of Seoul. In the process, we divided subjects into employed women and unemployed women groups and then used the Korean Version of Alcohol Use Disorder Identification Test (AUDIT-K), State-Trait Anxiety Inventory (STAI), and Barratt Impulsiveness Scale (BIS) to identify patterns in subjects' alcohol drinking, anxiety and impulsiveness. Results : Among the 925 respondents, 95.7% drank alcohol, and after the analysis, female problematic drinking ($12{\leq}AUDIT-K{\leq}25$) and alcohol dependence ($AUDIT-K{\geq}26$) was apparent in 61 (9.5%) and 2 respondents (0.3%), respectively. Female respondents who had jobs tended to drink more and exhibit higher ratios of problematic drinking, with a higher exposure to alcohol than those that were unemployed. The psychological attributes related to female respondents' alcohol problems related to state of anxiety and impulsiveness. Employed women respondents also showed a higher state of anxiety and impulsiveness than unemployed women. Conclusion : Controlling the frequency of exposure to alcohol, anxiety, and impulsiveness in employed women should be considered to be crucial controlling factors related to the hazards of excessive drinking.