• Korean Journal of Materials Research
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• v.4 no.5
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• pp.550-555
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• 1994

The effects of RTA treatment on the leakage current have been studied for tantalum pentoxide( $Ta_2O_5$) films deposited by PECVD on P-type(100) Si substrate using $TaCl_5$(99.99%) and $N_2O$(99.99%) gaseous mixture. The refractive index increased with increasing the deposition temperature and the maximum deposition rate was obtained at $500^{\circ}C$. The Ta-0 bond peak intensity of as-deposited $Ta_2O_5$ increased with increasing the deposition temperature through FT-IR analysis and the leakage current value was decreased with increasing the deposition temperature. The small leakage current value obtained after RTA treatment of as-deposited $Ta_2O_5$ was found to be due to the reduction of 0-deficient structure in the film. The increases of the oxygen coacentration and the Ta-0 bond peak intensity in the film after RTA treatment were measured by AES and FT-IR analyses.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.72-72
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• 2019

간무봉(555.8m)은 강원도 인제군 남면에 위치하고 있다. 북한강의 지류인 소양강으로 대부분 둘러싸여 있으며 북서쪽에 봉화산(874.4m), 북동쪽에 기룡산(940.4m)과 이어진다. 현재까지 간무봉을 대상으로 한 식물상 조사 이력은 없었으나, DMZ 일원에 위치하는 산이기 때문에 DMZ의 식물상 연구를 위한 기초 자료로 보전하고 탐색하는 의미가 있다. 현지조사는 2018년 4월부터 10월까지 총 6회 수행하였다. 간무봉에는 굴참나무, 신갈나무, 소나무가 우점하고 있는 형태였으며, 조사 결과 관속식물은 73과 175속 211종 3아종 27변종 4품종으로 총 245분류군이 조사되었다. 그 중 양치식물은 고비, 고사리삼, 십자고사리, 퍼진고사리 4분류군이고, 나자식물은 소나무, 일본잎갈나무 2분류군, 피자식물은 노랑제비꽃, 은방울꽃, 꽃향유 등 205분류군이었다. 이는 우리나라 관속식물 4,494분류군(국립수목원, 2016)의 5.45%에 해당한다. 간무봉에서 확인한 특산식물은 진범, 할미밀망, 갈퀴아재비, 병꽃나무 등 6 분류군이며, 희귀식물은 미치광이풀(LC), 말나리(LC) 2 분류군 이외에 VU 이상에 해당하는 희귀식물은 발견하지 못하였다. 그리고 침입외래식물(국립수목원, 2016)의 경우 미국자리공, 수박풀, 미국쑥부쟁이, 단풍잎돼지풀 등 17 분류군이었다. 간무봉 주변에는 경작지, 군부대 훈련장소 등이 있으며, 서쪽 사면은 이미 벌목이 많이 된 상태이며, 북동쪽도 마을과 더불어 경작지로 개간되어 있다. 따라서 주변의 외부에서 가해지는 인위적인 간섭이 많은 상태라고 볼 수 있으며, 이미 유입된 단풍잎돼지풀 등 생태계교란종에 의한 변화에도 유의할 필요가 있다.

• Journal of Korean society of Dental Hygiene
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• v.18 no.6
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• pp.921-932
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• 2018

Objectives: The aim of this study was to investigate the number of existing permanent teeth and the denture usage status in elderly adults aged 65 years and above living in metropolitan cities and to confirm the degree of oral health inequality caused by the differences in oral conditions in each metropolitan city using the Lorenz curve and the Gini coefficient. Methods: The raw data for the analysis were obtained from the dataset of the sixth Korea National Health and Nutrition Examination Survey conducted between 2013 and 2015. The subjects included 1,764 people who underwent oral examination and answered questions. The complex samples general linear model was used to analyze the number of existing permanent teeth adjusted for age and monthly household income. The proportion of edentulousness and the denture status was analyzed using complex samples crosstabs. Results: The number of existing permanent teeth in the elderly adults aged 65 years and above was lowest in Ulsan (15.41) and highest in Gwangju (20.44). The proportion of edentulousness was highest in Busan (14.5%) and lowest in Daejeon (4.0%). With regard to the proportion of denture users, Busan had the highest tendency for denture usage (50.4%) and Gwangju had the lowest tendency (34.9) (p=0.172). The Gini's coefficient for the number of existing teeth was lowest in Busan (0.332). Oral health inequality was most severe in metropolitan cities. Conclusions: We found that oral health inequality exists among elderly adults living in the metropolitan cities of Korea using the Lorenz curve and Gini's coefficient.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.199-203
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• 2018

Objectives: The market for bottled water is increasing steadily in South Korea. Bottled water contains several naturally occuring minerals, such as calcium, magnesium, sodium, and fluoride. Fluoride is proven to be effective in preventing dental caries. In South Korea, the maximum permissible concentration of fluoride is 2 ppm for bottled water and 1.5 ppm for tap water. The aim of this study was to investigate the fluoride content of different commercially available brands of bottled water in South Korea, and compare the measured fluoride concentration to the concentration written on the label of each brand of bottled water. Methods: Twenty-seven of the 59 different brands of bottled water produced in South Korea were investigated in this study. Three bottles of each brand were purchased from supermarkets, marts, and convenience stores in each region of Korea in August 2016. For each bottled water brand, the fluoride content was measured three times using a fluoride-ion selective electrode (Orion ionplus Fluoride Electrode 9609, Orion Research, USA). The calibration curve was generated using 0.2 and 2 ppm standard solutions, and confirmed using a 1 ppm standard solution. Results: The mean fluoride content of the 27 brands of bottled water was $0.374{\pm}0.332mg/L$ (range=0.040 to 1.172 mg/L). The fluoride content was labeled by the manufacturer, on each of the tested brands of bottled water. In eight brands, the labeled fluoride content differed from the experimental data. The minimum to maximum fluoride content measured from 10 brands showed a variation of 0.3 mg/L or more when compared to the labeled fluoride content. Conclusions: This study investigated the fluoride content of various brands of bottled water produced in South Korea and compared the measured fluoride levels with fluoride information on the bottle labels. To ensure that consumers are suitably informed regarding their exposure to fluoride, correct labelling of fluoride content in bottled water is important.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.136-144
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• 2018

Objectives: The aim of this study is to analyze the differences in factors related to the incidence of dental caries between children in fluoridated and non-fluoridated areas and compared the DMFT and DMFS scores to confirm the effect of water fluoridation program (WFP) in Geoje and Changwon. Methods: The oral health examination and questionnaire survey were conducted in fluoridated and non-fluoridated areas. The number of surveyed children aged 8, 10, and 12 years in the fluoridated and non-fluoridated area of two cities was 1,524 and 1,383, respectively. Self-recorded questionnaires included self-perception of their own dental health, daily toothbrushing frequency, intake frequency of cariogenic sweet snacks and beverages, experience of gingival bleeding, experience of unmet dental treatment, and use of oral hygiene device except for toothbrush and toothpaste. The prevalence of caries and fissure-sealant status were surveyed. The logistic regression analysis was used to analyze the difference in children's self-rated oral health status between the fluoridated and non-fluoridated area. The mean number of sealed teeth and surfaces, marginal means of the DMFT and DMFS scores adjusted for the difference in the samples' sex distribution, and region were compared between the fluoridated and non-fluoridated areas. Results: In the fluoridated area, the experience rate of unmet dental treatments was higher among children aged 10 years, intake frequency of cariogenic sweet snacks and beverages were higher among the whole sample, and experience rate of professional fluoride application were lower than in the non-fluoridated area. The DMFT score for permanent dentition adjusted for differences in sex, region, and mean number of fissure-sealed teeth in the fluoridated area was significantly lower among whole samples and 8-, 10-, and 12-year-olds alone than in the non-fluoridated area. Conclusions: WFP can alleviate oral health inequality because it is effective in reducing the incidence of caries among children is disadvantaged demographic, socioeconomic, and cultural contexts.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.101-108
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• 2018

Objectives: The Korea National Health and Nutrition Examination Survey (KNHANES) is a national surveillance system that has been assessing the health and nutritional status of Koreans since 1998. Based on the National Health Promotion Act, the surveys have been conducted by the Korea Centers for Disease Control and Prevention (KCDC). Methods: An oral examination as part of The National Health and Nutrition Examination was proposed to calculate the sample design and survey participation. The surveying system was presented by classifying the measurement environment, screening, and survey items by year, and the merits and limitations of using the data were suggested by examining the status of survey quality management and the process of disclosing raw data. Results: This nationally representative cross-sectional survey samples approximately 10,000 individuals each year and collects information on oral examinations and oral health interviews. Data for the oral health component of KNHANES was obtained to assess the oral health status of Koreans and determine the prevalence of dental caries and periodontitis. The oral health data quality control of KNHANES was composed of three parts: "Education Program" and "Field Training Program" for quality control of oral health examiners (dentists) by the professional academy, and "Data management" by the KCDC. After completion of the three-step data check, the indicators of dental caries, periodontal disease, and oral health behavior were published in the National Health Statistics. Conclusions: To achieve the goals of oral health indicators, we will continue to monitor so that we can use it as basic data for oral policies and carry out various linkage analyses related to oral diseases.

• Journal of Korean Academy of Oral Health
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• v.41 no.4
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• pp.296-302
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• 2017

Objectives: The water fluoridation program has been implemented since 2008, in a region of Geoje City. This study aimed to evaluate the effectiveness of the water fluoridation program on caries prevention in the permanent dentition. Methods: Evaluation surveys were conducted on 8-, 10- and 12-year-old children in the fluoridated and non-fluoridated regions of Geoje City, in 2015. The survey included 834 children from the fluoridated regions and 703 from the non-fluoridated regions. The data obtained from the survey were analyzed using the IBM SPSS statistical package version 23.0. The effectiveness of community water fluoridation in caries prevention was estimated by the differences in the decayed, missing, filled teeth (DMFT) and decayed, missing, filled surfaces (DMFS) scores, between the program and control groups. The mean numbers of fissure-sealed teeth and surfaces were adjusted to reduce their confounding effect. Results: The mean DMFT and DMFS scores (0.69 and 0.91, respectively) of 10-year-olds from the fluoridated regions, after adjusting for the numbers of fissure-sealed teeth and surfaces, were significantly lower than those of the 10 year olds (DMFT: 0.95, DMFS: 1.32) from the non-fluoridated regions. The effectiveness of water fluoridation on caries prevention in the permanent dentition, estimated based on the differences in the mean DMFT and DMFS scores, adjusted for the number of fissure-sealed teeth and surfaces, between the program and control groups of 10-year-old children, was 27.4% and 31.1%, respectively. Conclusions: These results suggest that the effectiveness of water fluoridation on caries prevention in the permanent dentition, in Geoje City was so high that this program should be implemented in other regions in Korea as well.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.103-113
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• 2021

This study was investigated to find out the distribution of flora and remarkable plants and factors and management measures for influx of wild disturbed plants in the Damyang area of Mudeungsan National Park. The field survey was carried out 8 times from May 2019 to October 2020. First of all, in the Damyang area of Mudeungsan National Park, a total of 603 taxa in 107 families, 349 genera, 531 species, 57 varieties, 5 subspecies and 10 forms. This result was found to be about 12.33% of the total 4,881 taxa of vascular plants in Korea. In addition, Rare plants were classified as 15 taxa. Floristic special and Korean endemic plants were identified as 85 taxa and 13 taxa, respectively. Lastly, the naturalized plants that appeared in the Damyang area of Mudeungsan National Park were observed in 45 taxa with 45 species of 16 families and 36 genera. Moreover the naturalization rate was 7.46% and the urbanization index was calculated to be 14.01%. The wild disturbed plants were found in a total of 4 taxa. Especially, a sheep sorrel(Rumex acetosella) was focused on managing for physica and biological control at Sinseondae Eoksaepyungjeon.

• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.1-23
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• 2021

This study conducted a survey on flora at Mt. susdolbon(508m), Mt. seongjubong (625.3m), and Mt. sulibong(596.2m), located in Yanggu-gun, Gangwon-do. A total of 403 taxa, including 6 forms, 43 varieties, 4 subspecies, 350 species, 255 genera, and 84 families, were surveyed in the three mountain areas. 18 taxa from 5 families of ferns, 3 taxa from 1 family of gymnosperms, and the dicotyledonous plants as 302 taxa from 69 families of the dicotyledonous plants were identified. The remarkable plants included 11 taxa of the Korean endemic plants, such as Populus tomentiglandulosa, Salix koriyanagi, Cimicifuga heracleifolia, Aconitum pseudolaeve, Clematis trichotoma, Echinosophora koreensis, Vicia chosenensis, Salvia chanryoenica, and Hemerocallis hakuunensis. The rare plants designated by the Korea Forest Service were 4 taxa, including Echinosophora koreensis as endangered species (EC), Cimicifuga heracleifolia, Epimedium koreanum, and Lilium cernuum. The Least Concern species (LC) were 13 taxa, including Persicaria orientalis, Exochorda serratifolia, Viola diamantiaca, Lithospermum erythrorhizon, and Trigonotis icumae. The invasive alien plants were 28 taxa, including Persicaria orientalis, Rumex crispus, Phytolacca americana, Cerastium glomeratum, Chenopodium album, Chenopodium ficifolium, Amorpha fruticosa, Robinia pseudoacacia, Trifolium pratense, Trifolium repens, Oxalis dillenii, Euphorbia supina, and Oenothera biennis, accounting for 6.9 percent of the 403 taxa of the surveyed plants.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.39 no.1
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• pp.20-30
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• 2021

The purpose of this study was to identify the ecological characteristics of Namhan Mountain Fortress Walls vascular plants through investigation and analysis of Namhan Mountain Fortress Walls and to provide basic data when establishing a plan for conservation and management of Namhansanseong Fortress Wall vascular plants. The result of this survey revealed 249 taxa composed of 77 families, 169 genera, 222 species, 5 subspecies, 19 varieties and 3 forms. In terms of life form of Namhan Mountain Fortress Walls, the appearance rate of Hemicryptophytes(H) was high. Rare plants was 1 taxa and Korea endemic plants was 5 taxa. The total number of floristic regional indicator plants was 15 taxa, gradeI 9 taxa, gradeII 2 taxa, gradeIII 3 taxa, gradeIV 1 taxa. Among them, Polygala tatarinowii Regel is considered to the most important(gradeIV), and it is first description because in Gyeonggi-do, as no additional forms have been confirmed other than this site. Plants identified as rock vegetation were found in 21 taxa. Invasive alien plants were identified 20 taxa. Plants distributed on the walls of Namhan Mountain Fortress, such as Aconitum longecassidatum Nakai, Clematis heracleifolia DC. var. tubulosa (Turcz.) Kuntze, Hylotelephium spectabile (Boreau) H.Ohba and Polygala tatarinowii Regel etc, are feared to decrease the number of species and individuals due to the loss of walls, the spread of invasive alien plant and human interference, so conservation and management measures are needed.