• Journal of dental hygiene science
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• v.17 no.1
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• pp.73-80
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• 2017

Periodontal diseases occur from the interplay between increased bacterial response and the response of the host immune system over time. Anxiety and depression can impair immunological defense mechanisms, causing accumulation of periodontopathogens and thus exacerbating periodontal disease. We investigated the relationship of anxiety and depression to periodontal diseases in Korean women. In this study, 3,551 women aged ${\geq}19$ years were evaluated based on data from the first year (2010) of the Fifth Korea National Health and Nutrition Examination Survey. The analysis of the factors that caused periodontal diseases revealed that dental floss or interdental toothbrush nonuse behaviors have been shown to increase the risk of periodontal disease (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.14~1.95). After adjusting for conditions such as age, marital status, income, educational level, economic activity, diabetes mellitus, smoking, drinking, and frequencies of toothbrushing and interdental cleaning, we found that anxiety and depression increased the risk of developing periodontal diseases (OR, 1.47; 95% CI, 1.04~2.09). People with anxiety and depression have a higher prevalence of periodontal diseases than people without anxiety and depression. Thus, periodic periodontal care and effective self-care education are needed to manage periodontal diseases.

• Journal of dental hygiene science
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• v.15 no.5
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• pp.569-576
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• 2015

The aim of this study was to assess the oral health knowledge, attitude and behavior among geriatric care workers in long-term care facilities. A self-administered questionnaire was obtained from 212 geriatric care workers attending a professional education program of 2014 dementia pilot project. The questionnaire consisted of 4 parts of the training experience (2 items), knowledge (16 items), attitude (13 items), and behavior (4 items) on oral health care. Collected data were analyzed by frequency analysis, independent t-test, and one-way ANOVA using SPSS Statistics ver. 20.0. The percentage of educational experience on oral care was 27.9% and most respondents answered that they have received the education about denture cleaning (98.3%) and brushing method (91.4%). The average knowledge score was $10.88{\pm}1.70$, and respondents showed high-level agreement in 8 of the 10 items in attitude questions. They revealed difficulties in providing oral care to the elderly people because of their lack of knowledge. The deficiencies of knowledge about oral care would have a decisive effect on not only oral and general health, but also quality of life of the elderly people. Therefore, it is required to develop professional oral care training programs for geriatric care workers and support systems should be legalized.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.421-431
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• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.567-578
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• 2001

To investigate the difference of Texture exhibited on interproximal enamel surface with each different stripping method and the susceptibility of proximal enamel to demineralization after stripping and the application of a topical fluoride go] and sealant, one hundred human premolars, which were Previously extracted for orthodontic reasons were evaluated by means of Scanning electron microscopy and laser fluorescence. The results were as follows : 1. No matter what the initial stripping instrument was the furrows that resulted from all the stripping methods were not completely removed by careful polishing. 2. Among the enamel surfaces that were treated with three different initial abrasive instruments, followed by the same polishing method (Sof-$Lex^{(r)}$ disks), the enamel surfaces that were treated with 700 crosscut carbide bur showed the smoothest surfaces. 3. The stripped teeth, no matter what the initial stripping instrument was, were less resistant to initial demineralization than untreated teeth. But no difference in caries susceptibility according to differently stripped methods was found (p<(0.001). 4. Teeth treated with APF-gel or sealant were mote resistant to demineralization than those treated without other treatment after stripping (p<0.001). 5. Comparing groups treated with APF-gel to groups treated with sealant, the former was more resistant to demineralization than the tatter (p<0.05). In conclusion, enamel surfaces that were stripped jnterproximally were less resistant to demineralization even though various attempts were made to produce smooth, self-cleaning enamel surfaces. Therefore, additional treatment-sealant or calcifying/ fluoridating solution To the stripped enamel surfaces is recommended.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.51-56
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• 2009

Safety and quality assessment systems are very important in manufacture, storage, transportation, and handling of hazardous materials(hazmat) to prevent hazmat disasters. At present, hazardous materials exist everywhere in our daily lives with various forms of plastics, household products of cleaning and washing detergents, fertilizers or petroleum-related products. However, hazardous materials are dangerous substances when they are released to human or environment. Hazardous materials become very widely used substances in the age of oil-based industrial economy. The Korean Ministry of Environment (KMOE) describes about one hundred thousand types of chemicals are produced and used worldwide. Over four hundred new chemicals are introduced in every year. A crucial question for the Korean hazardous material management may have been raised: Will you be safe from hazardous material incidents? The gas leak disaster at Union Carbide's Bhopal, India in 1984 that made over 6,400 people killed and 30,000 to 40,000 people seriously injured is the representative case for the safety of hazmat. Korea becomes vulnerable to hazmat disaster due to the development of high-tech industry. Thus, the risk assessment system is required to Korea for transferring abandoned hazmat management systems to self-correcting safety systems. This research analyzed characteristics of various hazmat incidents applying statistical analysis methods including frequency analysis or analysis of category data to hazmat incidents for ten years. All of three analyses of category data indicate the significance of causality between hazmat incident site groups and seasons, regional groups, and incident casualty groups.

• Composites Research
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• v.33 no.2
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• pp.68-75
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• 2020

Recently, the use of TiO₂ as a phtocatalyst has been diversely investigated due to its excellent durability performance and high photocatalytic reaction efficiency. Active researches have particularly focused on the development of TiO₂-incorporated cementitious composites in order to remove the atmospheric pollutants. Furthermore, the potential utilization of TiO₂-incorporated cementitious composites as road accessories such as tunnels, road median separators and soundproof walls in the form of tiles, blocks and structural components has been widely examined. In this regard, a thorough understanding on the material characteristics of TiO₂-incorporated cementitious composites should be preceded. The present overview article, therefore, revisits previous studies of TiO₂-incorporated cementitious composites and summarizes their various physicochemical properties and atmospheric pollutants removal performance.

• Journal of the Korean Vacuum Society
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• v.21 no.4
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• pp.205-211
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• 2012

We investigated the optical and hydrophobic properties of the deposited silver (Ag) zinc oxide (ZnO) nanorods (NRs) on flexible indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates (i.e., ITO/PET). The ZnO NRs were grown by an electrochemical deposition using a sputtered ZnO seed layer and the Ag was deposited by using a thermal evaporator. For comparison, the same fabrication process was carried out on the bare ITO/PET without ZnO NRAs. Due to the discrete surface of ZnO NRs, the deposited Ag was formed as nano-scale particles, while the Ag became film-like for bare ITO/PET. In order to control the size and amount of Ag particles, the Ag deposition time was changed from 100 to 600 s. When the deposition time was increased, the Ag particles became larger and denser, and the absorptance was increased. This enhanced absorptance may be due to the localized surface plasmon resonance of Ag particles. Furthermore, the relatively high hydrophobicity was observed for the deposited Ag on the ZnO NRs/ITO/PET. These improved optical and surface properties are expected to be useful for flexible photovoltaic and optoelectronic devices.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.3
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• pp.55-62
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• 2015

Recently as return farmers has been increased rapidly, the introduction of a system of rental housing is being considerated in order to induce regional fixation. It was examined organizational management, business scope of rural type rental housing, management role, through the analysis about the management realities of the business of similar form Rural-Fishing New Town project. Jangseonggun and Hwasungun have maneged rental housing 280ho in Rural-Fishing New Town project. It is large village among Rural Rental Housing. And these counties have organized the complex on a large scale among the rental housing. Local governments have managed and operated directly, also these governments have two different methods for the co-management, and the way of making payment. Rental housing management services are divided into rental management, housing management, tenant management. Rental management services such as residents of recruitment, tenants and retreat, rent collection and the storage, management and leasing promotion of the cantilever, surveys of residents. Housing management services such as check of various facilities, maintenance and maintenance work, security and cleaning and daily facility management. Tenant management is life management in connection with housing welfare. In the rural type of rental housing, there are few cases to operate a management office. It is often supplied by rental housing to buy a house or vacant land within the existing village. In this case, by utilizing community facilities within the existing village instead of establishment of extra facilities,It doesn't need to make payment for maintenance fee. In the smaller complex than No. 20, it is self-managed by the tenants in order to reduce the administrative costs and specify the necessary municipal manager. Organization form can be maneged directly from local governments and part of for the management of the building can be employed a mixed management system to delegate management to private organizations such as non-profit organizations or neighborhood association. Tenant management helps people who move in a rental house live on stable circumstance in there area by connection with the program of life support.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.41-46
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• 2014

The property improvement of polycarbonate coated with a multilayer film composed of an inorganic $SiO_2$ film and a photocatalytic $TiO_2$ film was studied. The $SiO_2$ film as a binder had an excellent light transmission characteristic. After the treatment with atmospheric pressure plasma, the surface of $SiO_2$ film showed the hydrophilicity, which increased the film coating uniformity with a $TiO_2$-containing aqueous solution. When $TiO_2$ film was over 200 nm thick, the absorption effect of UV rays in the range of 180~400 nm suppressed the yellowing phenomena of polycarbonate substrate. The inorganic film improved the heat resistance of polycarbonate substrates. $TiO_2$ film in the outmost under the exposure of UV rays promotes the catalytic oxidation characteristics and yields the capability to the decomposition of organic contaminants, and also increases the self-cleaning properties due to the increase of hydrophilicity. Structural stability of the polycarbonate substrate coated with inorganic $TiO_2$ and $SiO_2$ film was shown. The role of $SiO_2$ film between $TiO_2$ and polycarbonate substrate suppressed the peeling of $TiO_2$ film by inhibiting the photocatalytic oxidation effect of $TiO_2$ film on the polycarbonate substrate.

• Journal of Distribution Science
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• v.13 no.1
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• pp.105-118
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• 2015

Purpose - The objective of this study is to verify whether there are differences between Korean and Chinese consumers in the importance of the attributes such as shopping value and loyalty in social commerce. With the purpose of finding out these differences, the following questions are set up as research questions. First, will there be a difference between Korea and China in the importance of attributes of social commerce? Second, will there be a difference between Korean and Chinese consumers in shopping value? Third, will there be a difference between Korean and Chinese consumers in their loyalty? Research design, data, and methodology - The researchers collected data through self-administered questionnaires from Korean and Chinese consumers who had used social commerce within the past six months before answering the questionnaire. First, for social commerce users in Korea, comprising male and female university students in Chungcheong, a questionnaire was circulated. For social commerce users in China, university students within Beijing were surveyed. Responses to 336 questionnaires were used, excluding those with no answers or unreliable answers. Data coding and data cleaning were used. SPSS 18.0 was used. First, exploratory factor analysis is done to verify the validity of testing tools, and Cronbach's α coefficient is used to verify credibility. For factor analysis, the Varimax method is used. To verify the internal consistency reliability of each factor, the Cronbach's α coefficient is used to verify the credibility. Second, a T-test is done to verify differences between Korean and Chinese consumers for the importance of attributes. Third, ANOVA (Analysis of variance) is done to verify differences between Korean and Chinese consumers in shopping value and loyalty. Results - When Korean and Chinese consumers use social commerce, first, the importance of the attributes of social commerce is affected by four factors; playfulness and economic factors are more important to Korean consumers than Chinese consumers. As for informativeness factors, including product information and quality, and buyer comments, there was no confirmed difference between Korean and Chinese consumers. The convenience factor is more important to Chinese consumers than Korean consumers. Second, the factors affecting shopping value for Korean and Chinese consumers were hedonic shopping value and rational shopping value. To see the difference between Korean and Chinese consumers in shopping value factors, a t-test is conducted. As a result, in the rational shopping value factors of social commerce, Korean consumers scored higher than did Chinese consumers. These results were verified to be meaningful through statistics. In the hedonic shopping value factor of social commerce, Korean consumers scored higher than Chinese consumers. These results showed a significant difference. Third, loyalty in social commerce is higher for Chinese consumers than for Korean consumers. However, there is no difference in loyalty depending on sex. Conclusions - These results will hopefully be valuable and used in the future by Korean companies that wish to enter the Chinese social commerce market.