• 유통과학연구
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• 제17권7호
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• pp.65-76
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• 2019

Purpose - The purpose of this study is to investigate economical ventilation effectiveness to reduce hazardous materials exposure and damage of workers by analyzing exposure amount of noxious substances under various ventilation conditions of nail salon for indoor environments. Research design, data, and methodology - This study was carried out with cooperation of Nail shop located in SeongNam city to involve an analysis of the environmental impact indoor air quality, pollutant exposure and economical cost-effectiveness in the nail workplace. The hazardous substances were PM-10(Particulate Matter-10㎛), VOCs(Volatile Organic Compounds) and Formaldehyde, which are the major materials of nail workplace. Results - PM-10 is reduced by about 60% with air cleaner, forced artificial ventilation by 32%, and natural ventilation by about 12%. TVOCs and Formaldehyde showed similar efficiency (80~100%) after natural ventilation and ventilation after 60 minutes. The removal efficiencies of VOCs and formaldehyde were similar to those of natural ventilation and mechanical ventilation system. However, in case of dust, natural ventilation was reduced by artificial ventilation system due to inflow of external dust during natural ventilation. Conclusions - If the pollution degree of outdoor air is not high, air volume is high, and natural ventilation is performed when the air conditioning and heating system is not operated. Even at the end of the work, it keeps operating for 60 minutes to remove the pollutants generated. Results of this analysis demonstrated that the worker environment can be improved by adopting institutional legislation and guidelines for ventilation.

• 한국임상수의학회지
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• 제37권5호
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• pp.278-281
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• 2020

A 4-year-old Thoroughbred stallion was referred to J&C Equine Hospital with a quarter crack of the right front foot. On visual inspection, there was a medial quarter crack with laminar necrosis. The first step to treat this problem was to remove the necrotized tissue around the crack using Dremel tools, disinfecting crack, administering antibiotics through regional limb perfusion and systemically administering antibiotics and anti-inflammatory drugs consistently. After one month's anti-inflammatory management, the quarter crack was treated successfully using two series of wiring with one week's term and polymethylmethacrylate composites (Equilox^㉿). After treatment, this racehorse successfully resumed training and racing in Korea Racing Authority Seoul Race Course, and won three times, finishing second and third place once, out of thirteen starts.

• 한국토양비료학회지
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• 제46권6호
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• pp.458-462
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• 2013

A drainage ditch is normally a component of drainage networks in farming systems to remove surplus water, but at the same time, it may act as a major conduit of agricultural nonpoint source pollutions such as sediment, nitrogen, phosphorus, and so on. The hybrid turbidity reduction system using biodegradable check dam and synthetic polymer was developed in this study to manage pollutant discharge from agricultural farmlands during rainfall events and/or irrigation periods. The performance of this hybrid system was assessed using a laboratory open channel sized in 10m-length and 0.2m-width. Various check dams using agricultural byproducts (e.g., rice straw, rice husks, coconut fiber and a mixture of rice husks and coconut fiber) were tested and additional physical factors (e.g., channel slope, flowrate, PAM dosage, turbidity level, etc.) affecting on turbidity reduction were applied to assess their performance. A series of lab experiments clearly showed that the hybrid turbidity reduction system could play a significant role as a supplementary of Best Management Practice (BMP). Moreover, the findings of this study could facilitate to develop an advanced BMP for minimizing nonpoint source pollution from agricultural farmlands and ultimately to achieve the sustainable agriculture.

• Environmental Engineering Research
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• 제13권1호
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• pp.1-7
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• 2008

Recently a new technology called the flexible-fiber deep-bed filter (FDF) claimed to replace the conventional sand filter including coagulation and sedimentation filter (CSF) processes in the water treatment plant. Therefore the life cycle assessment (LCA) approach was applied for evaluating the life cycle impacts of FDF compared with those of CSF. The used LCA softwares were the Simapro 6 and PASS and their life cycle impact assessment (LCIA) methodologies were the Eco-indicator 99 and the Korean Eco-indicator, respectively. The goal of this LCA was to identify environmental loads of CSF and FDF from raw material to disposal stages. The scopes of the systems have been determined based on the experiences of existing CSF and FDF. The function was to remove suspended solids by filtration and the functional unit was $1\;m^3$/day. Both systems showed that most environmental impacts were occurred during the operation stage. To reduce the environmental impacts the coagulants and electricity consumptions need to be cut down. If the CSF was replaced with the FDF, the environmental impacts would be reduced in most of the impact categories. The LCA results of Korean Eco-indicator and Eco- indicator99 were quite different from each other due to the indwelling differences such as category indicators, impact categories, characterization factors, normalization values and weighting factors. This study showed that the life cycle assessment could be a valuable tool for evaluating the environmental impact of the new technology which was introduced in water treatment process.

• 한국산학기술학회논문지
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• 제17권8호
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• pp.379-388
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• 2016

현대 무기체계 제조를 위해 적용되는 수많은 생산 기술과 다양한 공정 환경으로 인해 다양한 결함이 무기체계 제조공정에 유입되고 있다. 이렇게 제조공정에 유입되는 결함 중 육안 검사, 기능 시험 등 기존 품질 관리 절차를 통해 검출할 수 있는 "명백결함(Patent Defect)"과 무기체계 복잡성과 제조공정의 복잡도로 기존 품질 관리 방식으로 검출이 제한되는 "잠재결함(Latent Defect)" 2가지 종류가 있다. 이러한 초기 결함 문제를 최소화하기 위해 무기체계 생산공정 중 유입된 결함요소를 환경부하(온도, 진동)를 활용하여 결함검출/제거/개선하기 위해 환경 부하 선별(ESS : Environmental Stress Screening) 시험을 수행해야 한다. 본 논문은 국내 무기체계 제조업체에서 정량적 환경 부하 선별 시험 설계의 어려움을 최소화하기 위해 MIL-HDBK-344(Environmental Stress Screening of Electronic Equipment)의 수학적 모델을 기반으로 정량적 환경 부하 선별시험 효과도 분석 및 프로파일 자동화 도구를 구현하였으며, 6가지(온도부하변수 3가지(온도범위/온도변화율/허용 잔류결함밀도), 진동부하변수 2가지(부하크기/허용 잔류결함밀도), 시험설계변수 1가지(허용 시험시간)) 시나리오를 통해 구현된 도구 유효성을 확인했다.

• 한국치위생학회지
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• 제17권6호
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• pp.1195-1206
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• 2017

Objectives: The purpose of this study is to analyze relationship between oral health status and subjective oral malodor awareness of public health students. Furthermore, this study aimed to recognize the importance of prevention and treatment of internal and external factors and to contribute to the correct oral health management behavior. Methods: The study subjects were 500 students from 5 health departments of 2 universities located in Jeollanamdo who participated in self-administered survey from September 1 to 15, 2014. For statistical analysis, SPSS 21.0 for Windows was used. Descriptive analysis and a Chi-square test were conducted to investigate the effects of general characteristics, health behavior, oral health behavior, and oral health status on subjective oral malodor awareness. Finally, to investigate the relationship between oral health status and subjective oral malodor awareness logistic regression analysis was performed. Results: Subjective oral malodor awareness was significantly higher in the group requiring dental care with the score of 1.63 (95% CI 1.00-2.65) compared to the group not requiring dental care. Subjective oral malodor awareness was significantly higher in the severe coated tongue group with the score of 5.31 (95% CI 1.45-19.40) and significantly higher in the moderate coated tongue group with the score of 2.56 (95% CI 1.61-4.08). Subjective oral malodor awareness was significantly higher in the often mouth breathing group with the score of 2.13 (95% CI 1.02-4.47) and significantly higher in the sometimes mouth breathing group with the score of 2.66 (95% CI 1.65-4.29). Conclusions: In order to prevent oral malodor, it is emphasized that regular dental checkups, proper brushing after the meal, and brushing of the tongue are necessary to remove the coated tongue. In addition, the use of supplementary oral care products is considered to be a meaningful oral health behavior.

• 한국치위생학회지
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• 제10권5호
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• pp.807-817
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• 2010

Objectives : The purpose of this study was to analyzes the job implementation of dental hygienist at dental hospital(university), dental clinic and general hospital in the city of Gwangju. Methods : The subjects in this study were dental hygienists who worked at dental hospital(university), dental clinic and general hospital in the city of Gwangju. A survey was conducted by post from June 10 to August 10. Out of the collected data, 204 answer sheets were analyzed. Results : 1. 'Medical & Dental history taking', 'Extra & Intra oral examination' and 'Dental hygiene care plane' in dental clinic were significantly higher than dental hospital(university) and general hospital(p<0.001). 'Remove of extrinsic stain' and 'Treatment of hypersensitivity tooth' in dental clinic and general hospital were significantly higher than dental hospital(university)(p<0.001). 'Preventive dental caries treatment' and 'Diet control' were shown the low frequency of job implementation. 2. Almost task elements of dental assistance duty shown that dental hygienists under the 24 years old were significantly higher dental hygienists over the 30 years old(p<0.05) and dental clinic and general hospital were significantly higher than dental hospital(university)(p<0.05) in frequency of job implementation. 3. 'Dental staff supervision', 'Patient management' and 'Dental chart arrangement' shown that dental hygienists over the 30 years old were significantly higher than dental hygienists under the 24 years old in frequency of job implementation(p<0.05). 'Infection control' of dental hygienists over 30 years old was significantly lower than dental hygienists under the 24 years old(p<0.001). Conclusions : The results of this study indicate that a scope of dental hygienists' job need to extend also in order to accomplish a job efficiently, is suggested that the effort is necessary to improve a quality of dental hygienist and to change of recognition of the dentist about dental hygienists' job.

• 디지털융복합연구
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• 제14권8호
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• pp.431-439
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• 2016

인간의 행복과 삶의 질 향상을 위한 시도를 디자이너가 하고 있다. 인류는 경제적 성장을 기반으로 개인이 행복을 느끼는 요소는 다양하다. 그러므로 절대적 디자인은 한계에 이른 것이다. 소비자와 해결 방법의 빠른 변화를 대변하는 도구가 필요하다. 현재는 조건이 변화하고, 변화에 반응하여 발전하는 도구는 존재하지 않는다. 이러한 필요성에 대한 해결의 방법으로 발전적으로 변화하는 곤충의 변태(變態)는 디자인적으로 의미가 있다. 벼가 일생에 환경의 변화와 조건을 5단계로 나누어서 해결하여야 할 문제를 명확하게 하였다. 변태하는 곤충 디자인은 생명공학의 발전과 더욱 의미가 있다. 그러나 인간에게 행복을 주는 환경과 조건이 변화하고, 이에 맞도록 도구가 변화하는 디자인을 위한 학문적 연구이기를 기원한다.

• 산업융합연구
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• 제18권1호
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• pp.97-107
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• 2020

예로부터 "갈증이 나면 물을 마셔 해소하고, 번뇌와 근심걱정은 술을 마셔 지워버리고, 피로회복과 정신을 맑게 하려면 차를 마신다"라고 하였다. 이처럼 차는 물과 술보다 오래 마실수록 몸과 마음에 아주 좋은 대자연이 준 귀한 진다(眞茶)이며, 사계절의 기후변화 특징에 따른 양생차를 마심으로써 건강을 유지하게 해준다. 이처럼 차에는 고대인들의 철학사상인 음양의 이치가 숨겨져 있기에 어떤 차를 어떻게 우려 마셔야 음양의 조화를 이루어 양생에 도움이 되는지를 옛 선인들은 알고 있었다. 차의 성분변화에 영향 주는 인자는 천지인의 복합적인 상호작용이 중요하며 그 중에서 차를 다루는 사람의 마음정신이 가장 중요하다. 차는 인간과 자연을 이어주는 교량역활의 천연 양생음료이다.

• 전자공학회논문지
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• 제53권1호
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• pp.43-50
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• 2016

낸드플래시 기반 저장장치는 성능 향상을 위해 다중 채널, 다중 웨이 구조를 통해 다수의 낸드 디바이스를 병렬 동작시키고 있다. 하지만 동시 동작하는 낸드 디바이스의 수가 늘어나면서 전력 소모 문제가 가시화되었으며, 특히 디바이스 간 복수의 피크 전류가 서로 중첩되면서 높은 전력소모로 인해 데이터 신뢰성과 시스템 안정성에 큰 영향을 미치고 있다. 본 논문에서는 낸드 디바이스에서 지우기, 쓰기, 읽기 동작에 대한 전류 파형을 측정, 이를 프로파일링하여 피크 전류에 대한 정의와 모델링을 진행하였고, 나아가 다수의 낸드에서 피크 전류 중첩 확률을 계산한다. 또한 시스템 수준의 TLM 시뮬레이터를 개발하여 다양한 시뮬레이션 시나리오를 주입하여 피크 전류 중첩 현상을 분석 한다. 본 실험 결과에서는 낸드간 피크 중첩 현상을 차단할 수 있는 간단한 전력 관리 기법을 적용하여 피크 전류 중첩과 시스템 성능 간의 관계를 살펴보고 이를 통해 성능 저하 최소화를 위한 피크 중첩 비율을 제시하였다.