• 제목/요약/키워드: Useful efficiency

검색결과 1,836건 처리시간 0.034초

활성탄 사용에 따른 습식세정시설에서의 대기오염물질 제거효율 평가 (Removal Efficiencies Estimation of Air Pollutants at Wet Scrubber Using Activated Carbon)

  • 신찬기;권명희;전종주;신대윤
    • 환경위생공학
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    • 제18권2호
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    • pp.87-93
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    • 2003
  • This study carried out to recommend adaptable technologies and countermeasures for performance improvement of Wet Scrubber(WS) in industrial waste incinerator. When not using the Activated Carbon(AC), the removal efficiency of dust and HCl is 73%, 92%. And particulate phase and gaseous phase dioxins removal efficiency was evaluated up to 31% and 12%. In this case, dioxins enrichment was not revealed in WS. When using the AC mixing with scrubbing water, the case of 1,000ppm, removal efficiency of particulate phase dioxins was about 51%, and gaseous phase dioxins was about 96%. The case of 2,000ppm, removal efficiency of particulate phase dioxins was about 55%, and gaseous phase dioxins was about 97%. And the case of 3,500ppm, the removal efficiency of particulate phase dioxins was about 35%, and gaseous phase dioxins was about 96% respectively. By this study, using the AC was more useful to remove the gaseous phase dioxins, and needed to use proper concentration of the AC, that in case of 3,500ppm, the particulate phase dioxins removal efficiency was more lower than other cases.

Real Time Monitoring of Energy Efficiency Operation Indicator on Merchant Ships

  • Barro, Ronald Dela Cruz;Kim, Jun-Seong;Lee, Don-Chool
    • Journal of Advanced Marine Engineering and Technology
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    • 제35권3호
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    • pp.301-308
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    • 2011
  • International Maritime Organization (IMO) proposed the Energy Efficiency Operation Indicator (EEOI) in 2005 and the Energy Efficiency Design Index (EEDI) in 2008 so as to address emission concern and regulation. Likewise, Ship Energy Efficiency Management Plan (SEEMP) and Greenhouse Gas (GHG) monitoring and management are also becoming an issue lately. This paper introduces the energy efficiency design index (operation indicator) monitoring system (EDiMS) software can continuously monitor $CO_2$, $NO_x$, $SO_x$, and PM values emitted from ship. The accurate inventory of ships GHG can be obtained from base of emission result during the engine shop test trial and the actual monitoring of shaft power and ship speed. In addition, the ability to store all exhaust emission and engine operation data can be applied as the useful tool of the inventory work of air pollution and ship energy management plan for the mitigation or reduction of ship emissions.

저속 2행정 디젤 기관의 소기 특성에 관한 연구 (A study on the scavenging characteristics in slow-speed two-stroke diesel engines)

  • 고대권;최재성
    • Journal of Advanced Marine Engineering and Technology
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    • 제19권3호
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    • pp.24-32
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    • 1995
  • The scavenging characteristics have a great influence on the performance of a diesel engine, especially slow-speed two-stroke diesel engines which are usually used as a marine propulsion power plant, and they are greatly affected by the conditions in the cylinder, intake and exhaust manifolds, and the opening and closing timing of scavenging ports or exhaust valves during the gas exchange process. Besides, there are many other factors to affect the scavenging characteristics and these factors interact each other very complicatedly. Therefore the simulation program of the gas exchange process is very useful to improve and predict the scavenging characteristics, due to the high costs associated with redesign and testing. In this paper it was attenpted to investigate the effect of the variation of the pressure ratio of intake to exhaust manifolds, and the variation of the opening and closing timing of a exhaust valve by using a computational program for a three-zone scavenging model which was developed by authors. The computed results showed that the scavenging efficiency and delivery ratio increased considerably, but the trapping efficiency decreased with increasing of the pressure ratio of intake to exhaust manifolds. The scavenging efficiency, trapping efficiency, and th conditions of the cylinder gases were affected by the opening timing of the exhaust valve, but the delivery ratio by the closing timing.

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자료포락분석을 활용한 일 병동 간호사의 성과평가 방안 (Performance Evaluation of Nurses in a General Ward Using Data Envelopment Analysis (DEA))

  • 박연홍;임지영
    • 가정∙방문간호학회지
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    • 제25권1호
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    • pp.67-77
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    • 2018
  • Purpose: The purpose of this study was to compare the efficiency of general ward nurses in hospitals using Data Envelopment Analysis (DEA). Methods: Participants were 30 nurses working at a general ward. Input variables were labor cost and time of direct nursing. Output variables were prevention rate of medication error and bedsores, and patient satisfaction. These variables were extracted using literature review and CVI of an expert group. Data were collected from September 18 to October 7, 2017. Data were analyzed using EMS 3.1 program for DEA and descriptive statistics. Results: The average efficiency score of 30 nurses was 0.986, which was very high over all. In the super-efficiency analysis of 11 nurses, their efficiency ranged from 1.0 to 1.047. In addition, when the current output was fixed, the labor cost of nurses did not affect efficiency. Conclusion: This study attempted a new approach concerning performance evaluation of nurses using DEA. This method was useful during appraisal of nurses. We suggest that various input and output variables that were not considered in this study should be added to develop a integrative performance analysis model for nurses.

대형선망어업의 동태적 생산효율성 분석 (Analyzing the Dynamic Productive Efficiency of Large Purse Seine Fishery in Korea)

  • 서주남;김도훈
    • 수산경영론집
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    • 제43권1호
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    • pp.11-18
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    • 2012
  • This study is aimed to estimate a dynamic productive efficiency by vessel of large purse seine fishery and analyze changes of them over times using a window/DEA method. In addition, based on estimation results, it aims to suggest production management implications for an viable development of fisheries. Results indicated that an annual efficiency change of large purse seine fishery was estimated at 0.77 for 2007~2008, 0.83 for 2008~2009, and 0.77 for 2009~2010, showing a decreasing trend. As returns on sales of vessels of large purse seine fishery showed a decreasing trend, the degree of efficiency of a vessel might be closely related to the fishing profitability. The Window/DEA method was used in this study to estimate the efficiencies of vessels for large purse seine fishery. This method is well known and widely used to analyze the dynamic efficiency and it can provide useful implications for management of input factors. As a limitation of this study, it was not able to provide detailed management ways to reduce inefficiencies. However, they can be investigated with data on managerial factor, human factor, distribution factors as a future study.

High Food Efficiency Ratio of Prepubertal Growth Period Leads to a Long-Term Susceptibility for Obesity and Insulin Resistance in Obesity-Prone and Obesity-Resistant Sprague Dawley Rats

  • Choi, Joo Sun
    • 한국식품영양학회지
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    • 제30권4호
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    • pp.830-840
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    • 2017
  • Excessive body weight gain during the growth period of early life may predispose individuals towards obesity and metabolic disorder in later life. We investigated the possibility of using the food efficiency ratio as an early indicator for predicting susceptibility to diet-induced obesity and insulin resistance. Four-week-old, prepubertal, male Sprague Dawley rats were divided into obesity-prone and obesity-resistant groups based on food efficiency ratio values after five days on a high-fat diet. Metabolic parameters measured after 2, 6, and 10 weeks, and specific phenotypes were compared with each group. Obesity-prone rats had higher increases in body weight and fat mass compared to obesity-resistant rats over the study period. Obesity-prone rats became glucose intolerant early in this study and remained so throughout the experimental period, with increases in fat weight and leptin levels occurring first, followed by increases in insulin level. Gluconeogenesis and insulin resistance significantly increased in obesity-prone groups in which activities of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase were increased and glucokinase activity decreased. Higher food efficiency ratio at an early age was closely correlated with body fat accumulation, hyperleptinemia, and hyperinsulinemia of middle and elderly age. We suggest a high food efficiency ratio in prepubertal subjects may be a useful predictor of future obesity and insulin resistance.

A Copper Shield for the Reduction of X-γ True Coincidence Summing in Gamma-ray Spectrometry

  • Byun, Jong-In
    • Journal of Radiation Protection and Research
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    • 제43권4호
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    • pp.137-142
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    • 2018
  • Background: Gamma-ray detectors having a thin window of a material with low atomic number can increase the true coincidence summing effects for radionuclides emitting X-rays or gamma-rays. This effect can make efficiency calibration or spectrum analysis more complicated. In this study, a Cu shield was tested as an X-ray filter to neglect the true coincidence summing effect by X-rays and gamma-rays in gamma-ray spectrometry, in order to simplify gamma-ray energy spectrum analysis. Materials and Methods: A Cu shield was designed and applied to an n-type high-purity germanium detector having an $X-{\gamma}$ summing effect during efficiency calibration. This was tested using a commercial, certified mixed gamma-ray source. The feasibility of a Cu shield was evaluated by comparing efficiency calibration results with and without the shield. Results and Discussion: In this study, the thickness of a Cu shield needed to avoid true coincidence summing effects due to $X-{\gamma}$ was tested and determined to be 1 mm, considering the detection efficiency desired for higher energy. As a result, the accuracy of the detection efficiency calibration was improved by more than 13% by reducing $X-{\gamma}$ summing. Conclusion: The $X-{\gamma}$ summing effect should be considered, along with ${\gamma}-{\gamma}$ summing, when a detection efficiency calibration is implemented and appropriate shielding material can be useful for simplifying analysis of the gamma-ray energy spectra.

레이저 계측용 일산화탄소 레이저의 동작 특성 및 그 응용 (Operational Characteristics of a Carbon Monoxide Laser for Instrumentationand its Applications)

  • 김용평;최종운;김규욱;원종욱
    • 한국광학회:학술대회논문집
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    • 한국광학회 1990년도 광학 및 양자전자학 워크샵
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    • pp.33-38
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    • 1990
  • The carbon monoxide laser is one of useful light sources for precision laser instrumentation because of tis high efficiency and wideband characteristics. In this presentation, the liquid nitrogen cooled cw CO laser which is developed in KSRI will be reviewed

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Multimedia를 활용(活用)한 동기적(動機的) - 교수적(敎授的) 개별화(個別化) 수업전략(授業戰略) (Individualized Motivational & Instructional Teaching Strategy using Multimedia)

  • 윤현상
    • 수산해양교육연구
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    • 제11권1호
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    • pp.43-58
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    • 1999
  • To instruct in accordance with learner's trait & preceding knowledge, letting the learner control the learning activities is the important task of educator & major goal of the Education Department this year. This article intends to provide useful Instructional Model for the teachers in fisheries marine high school, when they design the individualized teaching model using motivation. One of the major reason for the fisheries marine high school students' low learning achievement is due to the neglecting motivation elements in teaching - learning processes. Recently, with assistance of the information communication technology development, various teaching methods such as Individualized Multimedia Mediated Instruction, Internet Instruction, have come to the major method in activating motivation and computer-mediated instruction considering the learner's individual difference is the useful tools for the instructional efficiency. Because current navigation text book of fisheries marine high school have special characteristic considering the spacial context & time series from departing port to entering port, Teachers can maximize learner's learning accomplishment by using individualized multimedia & providing similar situation like a real navigation(simulating), representing this text characteristics. Thus this paper searches for the specifications of Keller's Motivation Model & Sweeter's Tutorial Model to solve instructional efficiency problems in fisheries marine high school & developed an efficient instructional design by integrating two models.

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A bond graph approach to energy efficiency analysis of a self-powered wireless pressure sensor

  • Cui, Yong;Gao, Robert X.;Yang, Dengfeng;Kazmer, David O.
    • Smart Structures and Systems
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    • 제3권1호
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    • pp.1-22
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    • 2007
  • The energy efficiency of a self-powered wireless sensing system for pressure monitoring in injection molding is analyzed using Bond graph models. The sensing system, located within the mold cavity, consists of an energy converter, an energy modulator, and a ultrasonic signal transmitter. Pressure variation in the mold cavity is extracted by the energy converter and transmitted through the mold steel to a signal receiver located outside of the mold, in the form of ultrasound pulse trains. Through Bond graph models, the energy efficiency of the sensing system is characterized as a function of the configuration of a piezoceramic stack within the energy converter, the pulsing cycle of the energy modulator, and the thicknesses of the various layers that make up the ultrasonic signal transmitter. The obtained energy models are subsequently utilized to identify the minimum level of signal intensity required to ensure successful detection of the ultrasound pulse trains by the signal receiver. The Bond graph models established have shown to be useful in optimizing the design of the various constituent components within the sensing system to achieve high energy conversion efficiency under a compact size, which are critical to successful embedment within the mold structure.