• 한국진공학회지
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• 제5권4호
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• pp.269-277
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• 1996

PLS 선형가속기 진공계는 클라이스트론 첨두출력 54MW, 펄스폭 4.1$\mu \textrm s$, 반복율 10Hz의 마이크로파 전력 공급상태에서 $2.6\times 10^{-6}$Pa의 진공도를 유지하고 있으며 $45^{\circ}C$ 운전조건에서 마이크로파 전력이 공급되지 않았을 때 진공도는 $2.4\times 10^{-6}$Pa이다. 설치 초기에 $3.0\times 10^{-11}Torr-l/sec-\textrm{cm}^2$이었던 가스방출율은 각 가속단위마다 약 140 GJ의 마이크로파 에너지가 전파된 현재 $1\times 10^{-12}Torr-l/sec-\textrm{cm}^2$이다. 주 장비로 사용중인 이온펌프는 모두 포화된 상태이며 60 l/s, 120 l/s, 230 l/s 이온펌프의 유효배기속도는 운전 영역에서 각각 45 l/s, 65 l/s, 140 l/s이다. 진공계 운전중 야기된 문제점들로는 이온펌프 및 진공 게이지 전원제어기의 오동작, 에너지 배가장치의 출력창, 전자총 및 가속관 종단부하의 진공누출 등이었다. 최근 일년간 총 41회에 140.8시간 운전 중지를 경험하여 98%의 가용도(availability)를 나타내었다. 추후 시험중인 도파관 밸브와 개발중인 가속관 종단부하가 설치된다면 가용도를 99.5% 이상으로 증가시킬 수 있을 것으로 기대한다.

• 대한임상검사과학회지
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• 제50권3호
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• pp.359-369
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• 2018

의료 관련 감염을 예방하기 위한 필수적 방법은 일관성이 있는 감염감시 시스템을 구축하고 효율적인 감시 통제를 수행하기 위해 신뢰할 수 있는 상황에 대해 진단을 향상시켜나가는 것이다. 또한 의료 종사자의 손과 의복 및 장비는 환자 관리 및 환경과 접촉하여 병원체가 오염되는 요인이다. 병원체를 가진 시설 표면(예: 침대 레일, 침대 옆 탁자), 음용수, 냉각탑용수, 내시경기구, 급식위생, 공기매개, 멸균검사, 내독소검사, 및 의료 장비를 포함한 의료 환경의 오염은 일반적으로 발생한다. 또한 이러한 감염원을 활동 감시를 통해 MLST, PFGE의 기법으로 역학분석을 수행한다. 따라서 HAI 예방을 위한 환경 감시배양 검사는 환자의 안전과 감염원의 차단을 향상시킬 뿐만 아니라 국가의 감염관리 시스템을 통제하여 최적의 효율적인 감염관리 예방을 가능케 하고 국가의 감염관리 시스템의 안전을 향상시킨다. 결론적으로 감시배양 검사의 표준화를 통해 실효성 있는 감염관리체계에 이바지하고 감염관리 전문인력으로서의 전문성을 확보하고자 한다. 이를 통해 표준화 마련의 일차적인 목표는 의료관련 감염을 줄이고 국가적 의료관리 체계를 향상시키는데 있다.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.74-80
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• 1984

시설규모(施設規模)가 작은 축소형(縮少型) 열저장장치(熱貯藏裝置)를 개발(開發)하기 위한 기초적(基礎的)인 연구(硏究)로 비교적(比較的) 열흡수능력(熱吸收能力)이 큰 염화칼슘, 황산(黃酸) 나트륨, 산성인산(酸性燐酸)나트륨 등(等)의 수화염류를 축열매체로 한 수직관형축열조(垂直管形蓄熱槽)를 제작(製作)하고 이들 축열장치(蓄熱裝置)를 이용(利用)한 축열매체의 열저장특성(熱貯藏特性)을 실험(實驗)을 통(通)하여 구명(究明)하기 위하여 수행(遂行)되었으며 그 결과(結果)를 요약(要約)하면 다음과 같다. 가. 수직관형축열조(垂直管形蓄熱槽)에서 반경방향 온도분포를 검토한 결과(結果), 본(本) 실험(實驗)에 사용(使用)된 모든 열매체는 가열과정(加熱過程)에서는 결정수(結晶水)의 감소(減少)로 인(因)한 발열현상(發熱現象)때문에 잠열현상(潛熱現象)이 나타나지 않았으나 냉각시(冷却時)에는 이들 축열매체중 염화칼슘이 가장 뚜렷한 잠열현상(潛熱現象)을 보였으므로 상변화를 이용(利用)한 축열매체로서 가장 적합(適合)하다고 사료(思料)되었다. 나. 가열(加熱) 및 냉각시(冷却時) 축열매체에 전달된 열량(熱量)은 같은 조건하(條件下)에서 염화칼슘의 경우(境遇)가 가장 많았다.

• 설비공학논문집
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• 제28권1호
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• pp.29-34
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• 2016

The friction factor unit was studied to find a more economic alternative compared to the conventional 30 mmAq/m. The pipe and pump for cooling water piping used in a failing were selected, and the friction factor unit was changed to calculate the pipe diameter and the brake shaft power. Based on current electric charges, After the brake shaft power was converted into operational costs based on current electric charges, then an economic analysis was conducted considering that incorporated the initial installation costs and operational costs for the pump. We found that the friction factor unit when using 20 mmAq/m is more economical than that with 30 mmAq/m, if the piping is used for more than 4 years. The small friction factor unit is desirable when the piping is used for quite a long period of time, and the selection of a more economic friction factor unit should considering the period of usage will be important.

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1417-1429
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• 2004

The objective of the paper was to study the drinking and other related behavior of dairy cows (Bos taurus). There were 142 Holstein dairy cows observed and compared in this study. The experiment was designed on the basis of two different housing systems (wet pad with forced ventilation cooling house and open house); two different seasons (winter and summer); four different stages (high milk yielding cows, low milk yielding cows, dry cows, and heifers); and grouping (home and visitor animals). All cows had free access to water. Dairy cows spent 13.8 min/day drinking in wet-pad house and 11.7 min/day in open house. owever, there was no significant difference in the duration of water drinking between these two housing systems (p>0.05). The water consumption was significantly higher in wet-pad housed animals (68 L/day) than open-housed animals (31.5 L/day) (p<0.05). A significant interaction between housing and grouping (p<0.05) was found. Home and visitor animals spent more time drinking in open house, wet-pad house, respectively. A highly significant interaction was found between housing and drinking time during the day (p<0.001). Animals in open house drank more during the morning (6:00 to 10:00 h), whereas wet-pad housed animals drank in the afternoon (14:00 to 15:00 h) and evening (18:00 to 20:00 h). The average time a cow spent in drinking in summer was not ignificantly different from that of drinking in winter. However, the water intake was significantly higher in summer (61.9 L/day) than in winter (38.6 L/day) (p<0.05). Drinking activity showed a highly significant interaction between season and physiological stage (p<0.01). High milk yield cows spent more time drinking in summer than in winter, whereas cows in all other stages followed the opposite drinking pattern. Grouping exchange did not influence the drinking behavior of dairy cows in either season (p>0.05); both home and visitor animals spent almost the same time in drinking water. A strong significant interaction between season and time during the day was found(p<0.01), suggesting that animal's high drinking frequency occurred during the daytime for both seasons, with a peak midday in winter and two peaks at 10:00 h in the morning and 19:00 h in summer. Thus, drinking behavior was associated with the cooler time of day in summer and with the warmer hours of day in winter. High and low milk yielding cows and heifers spent 15.3 min/day, 14.3 min/day, and 12.8 min/day, respectively, in water drinking activity, but there was no significant difference among them (p>0.05). There was, however, a significant difference in water drinking activity found in dry cows, which spent less time in drinking at 8.2 min/day (p<0.05).

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2609-2614
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• 2007

Shell & Tube type Oil Cooler is widely used for hydraulic presses, die casting machines, generation equipments, machine tools and construction heavy machinery. Temperature of oil in the hydraulic system changes viscosity and thickness of oil film. They have a bad effect to performance and lubrication of hydraulic machinery, so it is important to know exactly the heat exchanging efficiency of oil cooler for controlling oil temperature. But most Korean manufacturers do not have test equipment for oil cooler, so they cannot carry out the efficiency test of oil cooler and it is impossible to verify its performance. This paper includes information of construction of necessary utilities for oil cooler test and design and manufacture of test equipment. One can select the optimum product by obtaining performance data through tests of various kinds of oil coolers. And also the paper developed a program which can be easily used for design of 2D and 3D drawings of oil cooler.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.299-303
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• 1991

A lamp heated LPCVD equipment has been made. Wafer is heated by an array of fifteen tungsten halogen lamps above the front side of a wafer and pyrometer views the back side of the wafer through $CaF_2$ window. Reactor which consisits of a quartz window and a water cooled-stainless steel plate can be evacuated to $5{\times}10^{-3}$ torr with a rotary vane pump. By pyrolysis of $SiH_4$ at about $600^{\circ}C$, polysilicon has been formed on the silicon dioxide film. The measured results show that thickness nonuniformity is 15% and temperature nonuniformity is 1.1%. Because activation energy of pyrolysis of $SiH_4$ is very high, about 1.8eV, small temperature variation will induce large thickness nonuniformity. The main cause of temperature nonuniformity is unsymmetry of lamp power and an unbalanced cooling structure. Charls & Evans' SIMS result shows that the oxygen content in the deposited polysilicon is comparable to that of silicon substrate but carbon content is ten times higher.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권9호
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• pp.413-422
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• 2002

In a power plant, disturbance detection and diagnosis are massive and complex problems. Once a disturbance occurs, it can be either persistent, self cleared, cleared by the automatic controllers or propagated into another disturbance until it subsides in a new equilibrium or a stable state. In addition to the Physical complexity of the power plant structure itself, these dynamic behaviors of the disturbances further complicate the fault monitoring and diagnosis tasks. A data structure called a disturbance interrelation analysis graph(DIAG) is proposed in this paper, trying to capture, organize and better utilize the vast and interrelated knowledge required for power plant disturbance detection and diagnosis. The DIAG is a multi-layer directed AND/OR graph composed of 4 layers. Each layer includes vertices that represent components, disturbances, conditions and sensors respectively With the implementation of the DIAG, disturbances and their relationships can be conveniently represented and traced with modularized operations. All the cascaded disturbances following an initial triggering disturbance can be diagnosed in the context of that initial disturbance instead of diagnosing each of them as an individual disturbance. DIAG is applied to a typical cooling water system of a thermal power plant and its effectiveness is also demonstrated.

• 한국지열·수열에너지학회논문집
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• 제3권1호
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• pp.1-9
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• 2007

A steady-state simulation model for Dual-Source Heat Pump(DSHP) of 8RT was presented. A Dual-Source Heat Pump(DSHP) has been designed to make up for the conventional air source heat pumps. The performance evaluation has been conducted under internal standard test conditions such as ISO-13256-1 and KS C 9306. However, as test conditions such as entering water, indoor and outdoor air conditions could not be controlled to satisfy the standard test conditions in outdoor tests, a series of experiments have been conducted with the actual test conditions. Then, computer models for DSHP could be used for the standard condition have developed using EES program. The model was developed from basic thermodynamic principles and heat transfer relations. Most of the parameters were obtained with EES from the actual catalog data. The simulation results were in good agreement with the experiments.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.777-783
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• 2000

Composting by negative aeration is a reasonable proposition to control odor generated during composting process. Cattle manure and rice hulls mixtures were composted in a bin composting system by negative aeration. Continuous(CA) and intermittent(IA) aeration methods were applied to analyze the composting characteristics. The composting temperature and the ammonia emission during composting were investigated according to the aeration methods. The main problem for the negative aeration was the generation of condensate in the suction line of blower. The quantity of condensate was significant for continuous aeration. The aeration method should be modified to escape from the cooling effect of continuous aeration at the initial stage of composting. It took a longer time to finish a composting for intermittent aeration on account of lower aeration. It was concluded that the composting by negative aeration could be accomplished by either continuous or intermittent aeration method if the flow rate would be controlled more efficiently and the water vapor in suction line of blower could be removed effectively. Ammonia emission increased up to maximum value of 675ppm for continuous aeration while 300ppm for intermittent aeration. However, the cumulative value of ammonia emission was larger for intermittent aeration than for continuous aeration.