• 한국직업건강간호학회지
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• 제7권1호
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• pp.55-64
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• 1998

In order to investigate and compare the health risk factors of nurses in the operating room(OR nurse) and ward (WARD nurse), the questionnaire survey for subjective symptoms was carried out on 553 nurses(132 OR nurses and 421 WARD nurses) who were employed at seven hospital. The self-administered questionnaries were composed of low back pain, subjective fatigue symptoms, musculo-skeletal symptoms, psychological stress and reproductive function. The results were as follows : 1. In the type of working posture and working environment, there were significant difference between two groups for working posture, waist form, height of working table, satisfaction of chair, lifting & carring. 2. Job satisfaction, duration of work, height of working table, satisfaction of chair, lifting & carring were significantly associated the low back pain. 3. In the complaints of subjective fatigue symptoms, the total mean score was higher in OR nurse than WARD nurse, but there was not significant. The items that the mean score of OR nurse was significantly higher than WARD nurse were 'head feels muddled', 'apt to forget', 'feel choky'. 4. In the complaints of musculo-skeletal syrrptoms, the total mean score was higher in OR nurse than WARD nurse, but there was not significant. The item that the mean score of OR nurse was significantly higher WARD nurse was 'wrist discomfort or pain'. 5. The comparison of spontatenous abortion in married nurses who had the experience of pregnancy were significantly associated the stress risk group. 6. In all of OR and Ward nurses, the job satisfaction is associated with subjective fatigue symptoms, musculo-skeletal symptoms, and stress. In conclusion, it suggested that working posture, working environment, stress, and job satisfaction were health risk factors of nurses working in the operating room. Further prospective intervention studies should be conducted to educate right working posture, improve of working environment, decrease of stress, and increase of job satisfaction.

• 한국콘텐츠학회논문지
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• 제15권4호
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• pp.17-28
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• 2015

운영체제 상에서 동작하는 응용프로그램은 운영체제의 환경과 지원하는 표준 라이브러리들이 다르기 때문에 운영체제에 매우 높은 의존성을 가진다. 이러한 이유로 동일한 기능을 수행하는 응용프로그램도 운영체제에 따라 새롭게 구현해야 되며 이는 응용프로그램 개발 이후의 유지 보수나 관리 측면에서도 시간적, 경제적 낭비를 초래한다. 이를 해결하기 위해 Cygwin이나 MinGW 등의 연구가 진행되고 있지만, 가상환경이나 툴을 제공하는 것일 뿐 응용프로그램 자체에 대한 이식성을 지원하는 것은 아니다. 따라서 본 논문에서는 표준 C라이브러리와 POSIX를 이용한 래퍼 형식의 범용 운영체제를 위한 인터페이스 미들웨어를 설계하여 응용프로그램이 가상환경이나 코드 수정 없이 동일한 동작을 지원한다. 미들웨어는 API를 기본과 확장으로 분류해 선택적으로 적재하여 응용프로그램의 크기를 효율적으로 관리할 수 있도록 한다. 또한, 응용프로그램을 인터페이스 미들웨어를 탑재한 Linux, Unix, Windows와 Cygwin을 비교 실험하고 기능 및 성능 평가를 수행하였다.

• 한국물환경학회지
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• 제22권5호
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• pp.905-912
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• 2006

In this paper, simulation methods of the system dynamics model developed by Das et al. (1997) for activated-sludge wastewater treatment plants are illustrated in an attempt to determine the operating rules and the policies related to capacity expansion of an activated-sludge wastewater treatment plant. For existing conditions, the analyses were performed by varying activated-sludge return rate to observe changes in effluent water quality and treatment efficiency. The effluent water quality is also analyzed for various average daily inflow conditions and activated-sludge return rates. As a result, without expanding the aeration tank, maximum average daily inflow that can satisfy the effluent water quality standard of BOD $0.02kg/m^3$ was determined as $2,840m^3/hr$, subject to 100% of activated-sludge return rate while other factors remain constant. When the activated-sludge return rate is less than 100%, expansion of the aeration tank is necessary and minimum sizes of the aeration tank to satisfy the effluent water quality standard were determined for various activated-sludge return rates. In addition, the total operating and maintenance as well as unit treatment cost regression equations for activated-sludge wastewater treatment plants are suggested by using the cost data that are obtained from Water and Wastewater Division, Ministry of Environment. The regression analyses showed that the economies of scale phenomena exist in the operating and maintenance costs of activated-sludge wastewater treatment plants.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 1998년도 한국대기보전학회 추계학술대회 발표 논문집
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• pp.68-70
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• 1998

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2005년도 임시총회 및 학술논문발표회
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• pp.93-95
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• 2005

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1089-1096
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• 2008

The subway in Seoul, Korea has been constructed and operating 8 lines and 265 subway stations since 1974. And now it' been operated in the metropolis like Busan, Daegu, Gwangju, Incheon. The subway system is being given a great deal of weight on the public transportation system. It means that the citizens of seoul are getting exposured to the underground environment more and more. As the quality of life is getting better, the desire for a pleasant(healthy) environment has been increased. so we have to study effective environment management plans for the subway, When considering Indoor air pollution as another serious environment problem.

• 한국물환경학회지
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• 제20권1호
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• pp.86-92
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• 2004

Lab-scale experiments have been carried out to investigate ammonia stripping with a modified spray tower for removing ammonia nitrogen from swine wastewater. The operating conditions such as initial pH, temperature, air flow, hole size of distributor determining the diameter of water drops, and influent solids concentration were closely examined focusing on removal efficiency of ammonia. As a result of the experiment, in order to achieve high rate of ammonia removal by the air stripping system, the air flow rate must be supplied at high rate with sufficiently high initial pH, temperature. The optimum operating condition to meet the residual ammonia concentration of 300 mg/L was the initial pH of 11.0 at $35^{\circ}C$ with the air flow rate of 20 L/min. It also showed that the smaller hole size is, the higher removal rate of ammonia is expected. However, when used a small sized distributor (2 mm), the flooding problem at the upper column occurred due to clogging of the hole. With regard to the influent solids concentration, it was showed that the lower concentration of solids, the higher removal rate of ammonia. The removal of particulate materials in influent led to improve the removal efficiency of ammonia, rather than to control the operating condition including initial pH, temperature, and air flow. The empirical correlation between KLa and operating parameters would be driven as, $K_{La}=(0.0003T-0.0047){\cdot}G^{0.3926}{\cdot}L^{-0.5169}{\cdot}C^{-0. 1849}$. The calculated $K_{La}$ from proposed formula can be used effectively to estimate the optimum reaction time and to calculate the volume of modified spray tower system.

• 한국물환경학회지
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• 제23권5호
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• pp.636-641
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• 2007

A pilot-scale biofilm nitiritation reactor was operated with the reject water from a large wastewater treatment plant. The effects of various operating parameters including pH, temperature, dissolved oxygen, solids and organic concentrations were examined. A stable nitritation was achieved at operating pH range of 7.3 to 8.8 with an alkalinity addition. Higher operating temperature of $35{\pm}0.7^{\circ}C$ achieved more stable nitritation compared to $30{\pm}0.2^{\circ}C$. It has been noticed that nitrite accumulation maintained with DO, solids and organic concentrations range of 0.8 to 3.9 mg/L, 3,400 to 11,000 mg/L, and 86 to 572 mg/L, respectively. It seems that the accumulation of nitrite was caused by both the inhibition of $NO_2{^-}$ oxidizers due to free ammonia and the maintenance of the high operating temperature of $35^{\circ}C$ which promote to accumulate the $NH_4{^+}$ oxidizers in the reactor. According to microbial community analysis of fluorescence in situ hybridization and INT-Dehydrogenase measurements, more nitrifiers were presented in attached form compared to suspended growth.

• 한국정보과학회논문지:시스템및이론
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• 제33권9호
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• pp.626-633
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• 2006

무선 센서 네트워크는 자연 환경의 정보를 수집하고, 수집된 정보를 가공하고, 가공된 정보를 무선 통신을 통하여 사용자에게 실시간으로 전달하는 기능을 가진 설비이다. 이러한 무선 센서 네트워크는 수백 혹은 수천 개의 무선 센서 노드들로 이루어지고, 센서 노드의 플랫폼은 비용 효율성 때문에 매우 제한적인 메모리 공간을 지니며 제한적인 배터리로 동작한다. 따라서 이것들을 동작시키는 센서 운영체제는 공간 제약성을 감내할 수 있어야 하고, 에너지 효율적으로 동작해야 전체 센서 네트워크를 효율적으로 동작시킬 수 있게 된다. 본 논문에서는 공간 제약적인 센서 운영체제를 위한 효율적인 메모리 할당 기법을 제안한다. 제안한 기법을 사용하면, 기존 센서 운영체제들에서 사용되었던 메모리 할당 기법들을 사용하는 것보다 메모리 단편화 문제를 감소시킴과 동시에 공간의 효율성을 증진시킬 수 있다. 본 논문의 비교 실험 결과를 통하여 제안한 기법을 사용하는 것이 기존의 방법보다 메모리 단편화를 상당히 줄일 수 있고, 또한 수행 시간도 나빠지지 않음을 보인다.

• 해양환경안전학회지
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• 제20권4호
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• pp.398-404
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• 2014

우리나라 주요 항만에 규정되어 있는 정박지와 관련한 운영 세칙은 항만마다 정박지 운영 기준이나 정박지 선박수용능력에 대한 단위가 단일화 되어있지 않으며, 동일한 사안에 대해 다른 용어들을 사용하고 있다. 이로 인해 정박지를 운영하거나 이용하고자 하는 당사자들에게 큰 혼란을 주고 있는 상황이다. 본 연구에서는 국내 주요 항만의 정박지 운영 세칙을 검토하여 세칙명, 단위 및 용어의 단일화 방안을 제안하였다. 아울러 정박지 운영상의 혼란을 최소화하기 위하여 외국 주요 항만의 정박지 현황 검토를 통하여 향후 세칙 개정시 정박지 명칭 부여 원칙, 정박지 선박수용능력 단위 및 정박지의 수용가능한 선박 척수의 설정이 이루어지도록 제안하였다.