• 한국직업건강간호학회지
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• 제19권2호
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• pp.190-204
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• 2010

Purpose: This study was conducted to obtain the fundamental data on prevention and management of musculoskeletal symptoms, and to assess the prevalence, risk factors and job characteristics of musculoskeletal symptoms in hotel employees. Methods: The work sampling analysis was carried out by OWAS, and the prevalence was surveyed in term of NIOSH diagnostic criteria and work related risk factors on 263 hotel employees in Busan, Korea, using structured self-administered questionnaire from Jan. 20 to Feb. 26, 2010. The collected data were analysed by the SPSS 18.0. Results: 1) The prevailing rate of musculoskeletal symptoms by NIOSH diagnostic criteria was 43.80% for total subjects and 27.91% for shoulders, 12.79% for neck, and 11.24% for back/waist, respectively. 2) Factors affecting the prevalence of musculoskeletal symptoms were examined and multivariate logistic regression analysis was performed. As a result, women, having a burden of musculoskeletal work, increased work time in case of a higher risk of the prevalence of musculoskeletal symptoms (P<0.1). 3) The body parts and the department with the prevalence of musculoskeletal symptoms showed a significant difference (P<0.05) compared with symptoms on shoulders, arms/elbows, and ankles/feet. Conclusion: The prevalence of musculoskeletal symptoms by NIOSH diagnostic criteria in hotel employees was relatively high showing 43.80% for total subjects and higher in departments of laundry, reservations, cooking, food&beverage, dishwashing, and room cleaning than others.

• 대한기계학회논문집B
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• 제41권3호
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• pp.205-209
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• 2017

고온으로 가열된 고체 표면 위를 타원형 액적이 충돌할 때, 구형 액적 충돌 거동과 다른 비축대칭적인 퍼짐 거동이 발생하여 반동 높이 조절이 가능하다고 보고되었다. 본 연구에서는 타원형 액적 종횡비가 퍼짐 거동에 미치는 영향을 조사하였다. 충돌 거동은 동기화된 두 대의 고속카메라를 이용하여 두 측면에서 관찰하였고, 액적의 장축과 단축에서의 액적 퍼짐 너비를 각각 조사함으로써 퍼짐 특성을 분석하였다. 실험 결과에서 종횡비가 클수록, 액적 단축의 최대 퍼짐 너비는 증가하는 데 반해, 액적 장축의 것은 큰 변화가 없는 것으로 나타나는 데, 이는 수축 과정에서 액적 정렬을 촉진하고 반동 억제에 중요한 역할을 한다. 본 연구에서는 추가적으로 액적 종횡비와 충돌 속도가 동시에 큰 영역에서 발생하는 반동 거동과 액적 분열 현상에 대하여 고찰하였다.

• 조명전기설비학회논문지
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• 제18권1호
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• pp.28-35
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• 2004

질소는 안정한 가스로서 잘 알려져 있지만, 해리, 여기, 선리 등의 반응이 일어나기 시작하면 활성도가 높아지게 되고 오랫동안 유지되는 특성을 갖고 있다. 이러한 반응 및 전송과정을 이용하는 예가 많은 분야에서 볼 수 있다. 현재 질소 가스만의 특성 분석 연구에 관한 보고는 상당히 부ㅈㄱ하며 이러한 부분에 대한 연구가 필요하다고 볼 수 있다. 본 연구에서는 질소 플라즈마의 특성을 상세하게 이해하기 위해, 용량 결합형 프라즈마의 1차원 유체 모델에 의한 시뮬레이션을 행하였다. 하전입자의 밀도, 공가 전계 및 전자 에너지 등의 기본적인 움직임을 혹인하고, 전기적으로 정의 가스에서는 발생？ 않는 전기적 이중층의 형성을 분석하였다. 또한 전원 전압을 300∼700 [V] 로, 압력을 0.2∼2.0 [Tow] 로 변화시켜, 그에 따른 플라즈마를 구성하는 각 입자들의 특성을 고찰하였다.

• 전기학회논문지P
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• 제64권3호
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• pp.182-186
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• 2015

We investigated that effects of annealing ambient on the characteristics of functional nano thin film synthesized on glass substrate. The functional nano thin films were annealed by using rapid thermal annealing (RTA) equipment in vacuum, oxygen and nitrogen ambient, respectively. The hardness of the functional nano thin films were measured by a standard hardness testing method (ASTM D3363) such as a H-9H, F, HB and B-6B pencil (Mitsubishi, Japan). Also, the adhesion of the functional nano thin films were measured by a standard adhesion testing method (ASTM D3359) using scotch tape (3M, Korea). The contact angle of the functional nano thin films was measured by a contact angle analyzer (Phoenix 300 Touch, S.E.O.). The optical property of functional nano thin films was measured via UV-visible spectroscopy (S-3100, Scinco).

• 한국산업보건학회지
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• 제23권2호
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• pp.41-49
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• 2013

Objectives: The purpose of this study was to clarify the association between serum carcinoembryonic antigen (CEA) and type of work in the shipbuilding industry. Methods: 1,072 final study subjects were admitted to a general hospital from April through July 2010 for the purpose of medical examination. Data on general characteristics such as age, smoking history, alcohol history and exercise habits was gathered through structured self-administered questionnaires. Information on job factors was collected from a medical examination, by interview and through company personnel data. Serum CEA levels were measured after eight hours' fasting and were analyzed by a radioimmunoassay. Results: On univariate analysis, the mean serum CEA level was significantly higher among married (p=0.02), older age (p<0.01), longer work time (p<0.01), smokers (p<0.01), lower education (p<0.01), and indirect and direct exposure groups (p<0.01). On multiple regression analysis, serum CEA level was influenced by smoking (p=0.001), duration of work (p=0.019), and direct exposure group (p<0.001). However, among the direct exposure group, serum CEA level was not significantly different between welding, mounting, electro-device constructive work, grinding and cleaning, and painting. Conclusions: The goal of this research was to determine if there were differences between serum CEA levels according to occupational role among shipyard workers. The direct exposure group of shipyard workers had a relatively higher level of serum CEA than did the indirect exposure group and office workers, most likely due to occupational exposure.

• 한국진공학회지
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• 제21권3호
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• pp.158-163
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• 2012

본 연구에서는 폴리머 애자의 자가세정 코팅을 위한 소재로써 $TiO_2$ 박막을 실리콘과 유리, 폴리머애자 기판위에 증착하였다. $TiO_2$ 박막은 $TiO_2$ 세라믹 타겟이 부착된 RF 마그네트론 스퍼터링 장치를 이용하여 증착하였다. $TiO_2$ 박막은 스퍼터링의 다양한 공정조건 중 RF 파워의 크기에 따라 100 nm의 두께로 증착하였다. RF 파워에 따라 증착되어진 $TiO_2$ 박막의 접촉각, 표면거칠기등 표면 특성을 확인하였으며, UV-visible등 광학적 특성을 고찰하여, 구조적 특성과의 관계를 고찰하였다.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.443-450
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• 2008

고유가 대응방안으로 저등급 석탄의 효과적인 활용기술에 대해 고찰하였다. 현재 산업체에서 사용하는 석탄 중에 갈탄과 아역청탄이 저등급 석탄에 속하며 매장량이 풍부하고 세계적으로 고르게 분포되어 있지만 높은 수분 함량과 자연발화 가능성으로 인해 활용이 많이 되지 않고 있다. 본 논문에서는 저등급 석탄으로부터 화학적 정제기술을 이용하여 초청정석탄을 제조하는 기술에 대하여 고찰하였다. 회분 제거기술인 UCC 공정과 가연성분 추출기술인 Hyper Coal 공정을 비교하였다. 회분 제거기술인 UCC(Ultra Clean Coal) 공정은 Hyper Coal 공정에 비해 단순하다는 장점이 있지만 생성물의 회분 농도가 0.1% 이상으로 높다. 가연성분 추출 기술인 Hyper Coal 공정은 용매추출과 이온제거공정 등 구성은 복잡하지만 회분이 200ppm 이하로 생성된다. 초청정석탄은 오일과 동일 등급의 초 청정연료로써 산업용 석유를 대체하고 장기적으로는 IGCC와 IGFC, 그리고 차세대 고도연소기술의 연료로 활용될 수 있을 것이다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.281-284
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• 2011

최근 유사석유제품 판매와 정량주유를 하지 않는 주유소로 인해 많은 운전자들이 피해를 입고 있고, 이러한 현상들이 점점 증가하여 앞으로 그 피해는 더 늘어날 전망이다. 유사석유제품을 사용함으로써 발생하는 피해는 연료계통의 윤활작용 및 자가 청정기능 문제, 부품의 조기 노후화 및 연료계통의 불순물 누적, 정품 휘발유와의 연소속도 차이로 인한 엔진의 부담 가중, 배기가스의 유독성물질 배출, 엔진오일과 확인되지 않은 화학적 반응 등이 발생하게 되는 문제점이 있다. 이러한 피해를 예방하기 위해 OBD-II 프로토콜로 자동차의 주행 내부정보를 받아 유사석유제품과 정량주유를 측정하고자 한다. 본 논문에서는 WinCe 기반의 개발보드를 이용하여 WiFi 통신을 지원하는 OBD-II 스캐너를 통해 주행 내부정보를 받아와서 현재 차량의 유사석유제품판별 시스템과 정량주유 시스템을 구현하였다.

• 한국식품조리과학회지
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• 제25권3호
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• pp.283-296
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• 2009

This study examined food safety management at preschool establishments in Daegu and Gyeongbuk province, to provide data that can be used for food safety improvements. Field assessments of 60 foodservice establishments were executed from July to October, 2007. Statistical analyses of the data were conducted using the SPSS package program (version 14.0 for windows). The results are summarized as follows: 93.3% of the preschool foodservices were self-operated, and 24.1% of the child care centers and 96.7% of the kindergartens had employed dietitians. According to the averaged food safety evaluation scores the kindergartens (80.73) had a significantly higher score than the child care centers (50.37), and the public centers (85.00) had a significantly higher score than the private centers (54.29). While the average score of facilities that employed dietitian (73.58) was significantly higher than that of facilities that did not employ a dietitian (52.65). In addition, the average score of facilities that served meals in a dining room (80.83) was significantly higher than that of facilities that served meals in a classroom (59.33). The highest scoring food safety items included verifying employee health inspection reports (1.87), utilizing non-municipal water and routinely cleaning and well-maintaining the water storage tank (1.85), and disposing small amounts of leftovers in a vat after serving (1.83). In contrast, the lowest scores were for physical separation of clean areas and unclean areas to prevent cross-contamination (0.52), and physical separation between staff and food material entry areas (0.62). In conclusion, the preschool foodservice evaluated in this study required improvements in food safety management, and many of the child care centers were in need of immediate attention. To improve food safety at these establishments, administrators should implement prerequisite food safety programs.

• 대한치과의사협회지
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• 제54권12호
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• pp.1035-1044
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• 2016

Purpose : The purpose of this study was to compare the plaque removal effects of vacuum oral cleaner developed for the patients with limited mobility with those of manual toothbrushes and high pressure injection oral cleaner (dental water jet). Meterials and methods : Thirty human subjects were measured with Patient Hygiene Performance index (PHP index) and O'Leary index before and after the use of toothbrush, high pressure injection oral cleaner and vacuum oral cleaner. These three different oral hygiene methods were conducted with seven-day intermittence. Then the statistical analysis was carried out to define plaque removal rate of three different oral hygiene methods (${\alpha}=.05$). Results : According to the efficacy analysis of plaque removal before and after the oral cleaning using each of three methods, significant reduction in plaque after the treatment compared to the previous state when using toothbrush, high pressure injection oral cleaner, and vacuum oral cleaner was observed (P < 0.001). PHP index of tooth brushing was higher than that of the high pressure injection oral cleaner, while PHP index of vacuum oral cleaner did not show significant difference from either of the other two methods. There was no significance difference in O'Leary index among the three methods. Conclusion : Effect of plaque removal using the vacuum oral cleaner is comparable to that of manual tooth brush or high pressure injection oral cleaner, so it will be helpful for self-oral hygiene care of the patients with limited mobility.