• 제목, 요약, 키워드: Expected efficiency

검색결과 2,327건 처리시간 0.038초

지표대기 미세먼지 정화를 위한 식물체 음이온 발생량 분석 및 음이온의 미세먼지 기대정화지수 평가 (Evaluation on the Expected Purification Efficiency of Air Ion and Analysis on the Generated Amount of Negative Air Ions by Plants for the Purification of Particulate Matter in Air)

  • 오득균;주진희
    • Journal of Environmental Science International
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    • v.29 no.6
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    • pp.623-631
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    • 2020
  • This study analyzes the effect of negative air ions on the concentration of airborne particulate matter and evaluates the expected purification efficiency of open spaces for particulate matter by investigating the amount of negative air ions generated by plants. This study establishes a negative air ion generation treatment environment, plant environment, and control environment to measure the purification efficiency of particulate matter under the conditions of each, analyzing the expected purification efficiency by designing a particulate matter purification model. Results show that the amount of generated negative air ion according to environment was negative air ion generation treatment environment > plant environment > control environment; this order also applies to the particulate matter purification efficiency. Moreover, it took 65 min for the negative ion generation treatment environment, 90 min for the plant environment, and 240 min for the control environment to reach the standard expected purification efficiency of particulate matter concentration of 960 mg/㎥ for PM10. For PM2.5, with the designated maximum concentration of 700 mg/㎥, it took 60 min for the negative ion generation treatment environment, 80 min for the plant environment, and more than 240 min for the control environment. Based on these results, the expected purification efficiency compared to the control environment was quadrupled in the negative ion generation treatment environment and tripled in the plant environment on average.

이자율모형을 이용한 우리나라 기대인플레이션의 추정 및 특징 (Analyzing Expected Inflation Based on a Term Structure Model: A Case of Korea)

  • 송준혁
    • KDI Journal of Economic Policy
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    • v.36 no.2
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    • pp.65-101
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    • 2014
  • 본 연구에서는 이자율 변수에 적절한 확률과정을 부여하고 이를 가격함수에 직접 대입한 뒤 최종적으로 자산가격 PDE를 도출하는 재무모형을 이용하여 우리나라 기대인플레이션을 추정하고 그 특성을 살펴보고자 한다. 우리나라의 기대인플레이션은 글로벌 금융위기 이전에는 4%를 상회하는 높은 수준을 보였으나 2008년 후반을 기점으로 하향 안정화되는 모습을 시현했다. 또한 수익률곡선에서 도출된 기대인플레이션과 서베이 등을 통해 실제로 자료의 입수가 가능한 기대인플레이션을 이용하여 경제주체의 기대인플레이션 형성에 체계적인 편의가 존재하지 않고(불편성), 기대형성에 활용 가능한 모든 정보가 반영되었는지(효율성)를 기준으로 합리성을 평가한 결과, 분석에 이용된 모든 기대인플레이션에서 효율성은 기각되나 기대편의는 발생하지 않는 것으로 나타났다. 한편, 실제인플레이션과 기대인플레이션 간의 Granger 인과관계 검정 결과, 대체로 컨센서스 및 BOK 전문가 기대인플레이션은 상대적으로 장기의 실제인플레이션과, 이자율모형에서 도출된 기대인플레이션은 단기의 실제인플레이션과 상호 인과관계가 발생하는 것으로 분석되었다. 이러한 결과는 각각의 인플레이션 지표들이 내포하는 인플레이션의 정보가 상이하다는 것을 방증하고 있다. 이는 중앙은행이 하나의 인플레이션 지표보다는 다양한 지표들을 균형 있는 시각으로 관찰하는 것이 필요함을 시사한다.

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장방형 침전지내 도류벽의 침전효율에 대한 영향 평가 (Evaluation of the Effects of the Longitudinal Baffle on Settling Efficiency within Rectangular-shaped Sedimentation Basin)

  • 박노석;김성수;서인석;민경은
    • 상하수도학회지
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    • v.23 no.5
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    • pp.573-581
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    • 2009
  • In the case that the average velocity within rectangular-shaped sedimentation basin is less than 1.5cm/sec, and Froude number less than $10^{-6}$, it can not be expected that the longitudinal baffle improves the sedimentation efficiency. Also, since relatively lower velocity increases the effect of geostrophic body force, asymmetric flow pattern on a plane occurs within the basin. From the results of CFD (Computational Fluid Dynamics) simulation, in the case that the highest velocity within rectangular-shaped sedimentation basin is over 1.5cm/sec, and Froude number over $10^{-6}$, it can be expected that the longitudinal baffle installed within rectangular-shaped sedimentation basin improves the sedimentation efficiency.

Numerical Investigation of Purcell Enhancement of the Internal Quantum Efficiency of GaN-based Green LED Structures

  • Choi, Young-Hwan;Ryu, Guen-Hwan;Ryu, Han-Youl
    • Current Optics and Photonics
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    • v.1 no.6
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    • pp.626-630
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    • 2017
  • GaN-based green light-emitting diode (LED) structures suffer from low internal quantum efficiency (IQE), known as the "green gap" problem. The IQE of LED structures is expected to be improved to some extent by exploiting the Purcell effect. In this study, the Purcell effect on the IQE of green LED structures is investigated numerically using a finite-difference time-domain simulation. The Purcell factor of flip-chip LED structures is found to be more than three times as high as that of epi-up LED structures, which is attributed to the high-reflectance mirror near the active region in the flip-chip LED structures. When the unmodified IQE is 20%, the relative enhancement of IQE can be greater than 50%, without utilizing the surface-plasmon coupling effect. Based on the simulation results, the "green gap" problem of GaN-based green LEDs is expected to be mitigated significantly by optimizing flip-chip LED structures to maximize the Purcell effect.

Commercial Office의 Facility Management(FM) 업무 현황 분석을 통한 성과 평가체계 구축 방안 (A Study On the Development of Facility Management Performance Evaluation system by Analyzing Current FM Practices of Commercial Office Buildings)

  • 윤종한;차희성
    • 한국건축시공학회:학술대회논문집
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    • pp.89-90
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    • 2016
  • Despite the rise of importance of Facility Management(FM), relatively little attention was paid to evaluate FM efficiency and drive for greater FM efficiency. The purpose of the present paper is to offer a quantitative analysis of 14 Key Success Factors(KSF) and 22 detailed maintenance practices in order to develop FM evaluation system. In addition, from survey with Owner/Property Manager group and Facility Manager group, the present paper measures both importance of detailed maintenance practices and performance satisfaction. It is expected that by using the result of this survey, this paper helps increase efficiency in FM. Moreover, It is expected that this paper will be used as base line data in developing FM practice evaluation system.

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한우 농가 수익성 향상을 위한 번식 및 출하 계획 (Reproduction and marketing plans for improving profitability of Korean native cattle (Hanwoo) farm)

  • 최인철;조재성
    • 한국수정란이식학회지
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    • v.31 no.3
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    • pp.267-272
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    • 2016
  • Wholesale beef price is the critical factor for determining Korean native cattle, Hanwoo, farm's income in short-term. Wholesale beef price has seasonality due to high demand in Korean traditional holidays such as Korean thanksgiving day and lunar new year's day. Therefore, it is important to make reproduction and marketing plans for Korean Hanwoo farmers, in order to increase their farm income. However, there is no study available on changes in the expected farm income depending on reproduction and marketing schedules. This study analyzed the expected farm income per head depending on the monthly-based marketing schedules. The analysis was conducted based on the seasonality of wholesale beef price, reproduction efficiency, operating costs, relationship between carcass grade and slaughter age. The result shows that slaughter Hanwoo at the age of 29 months-old in August and January generating the highest expected farm income per head.

문화정보화 부문의 통합전산환경 구축.운영의 기대 성과분석 (An Analysis on the Expected Performance of Constructing and Operating the Integrated Computing Environment in case of Culture Informatization)

  • 정해용;김상훈
    • 한국컴퓨터정보학회논문지
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    • v.11 no.1
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    • pp.203-222
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    • 2006
  • 본 연구에서는 문화관광부의 소속기관 및 산하단체의 정보시스템 운영환경을 통합한 문화정보 통합센터의 구축 운영을 가정한 사례를 중심으로 기대성과를 분석하는 방법론을 제시하였다. 본 연구의 주요 목표로는 첫째, 문화정보 통합전산환경 구축 운영에 따른 성과를 사업적 기대가치와 전략적 기대가치로 구분하여 성과항목을 도출하도록 하였으며, 둘째, 사업적 기대가치의 경우에는 균형성과표(BSC) 관점에서 핵심성공요인(CSF) 기법을 이용하여 정보화업무 효율화성과, 조직혁신 및 발전성과, 대민서비스 향상성과, 문화적 가치제고 성과 등 4가지 관점으로 범주화하여 세부 성과항목을 도출하는 방법을 제시하였다. 셋째, 사업적 기대가치중 정보화업무 효율화 성과의 경우에는 TCO(Total Cost of Ownership) 관점에서 경제적 성과 측정을 위한 세부 평가항목 및 평가지표를 개발하고 문화정보화 부문의 사례를 중심으로 구체적인 측정방법을 제시하였다.

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트랙터 전동라인의 전동효율 특성 분석 (Characteristics of Power Efficiency of Tractor Driveline)

  • 류일훈;김대철;김경욱
    • Journal of Biosystems Engineering
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    • v.27 no.1
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    • pp.19-24
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    • 2002
  • According to the field test, the transient power transmission efficiency of a tractor driveline fluctuated in a range of 56 to 86% and the mean value was about 72.5%. Therefore, the constant efficiency model commonly used for a simulation of power performance was not proper far predicting such a variable of efficiency. In order to predict power efficiency more accurately, new concepts of the maximum efficiency and drag torque were introduced and a new model based on the these concepts was proposed. The difference between measured and model-predicted efficiencies was about 1.5% in average with a standard deviation of 1.1%. The new power efficiency model was expected to enhance the accuracy of predicting power transmission efficiencies of tractor drivelines.

Asymptotic Relative Efficiency of t-test Following Transformations

  • Yeo, In-Kwon
    • Journal of the Korean Statistical Society
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    • v.26 no.4
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    • pp.467-476
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    • 1997
  • The two-sample t-test is not expected to be optimal when the two samples are not drawn from normal populations. According to Box and Cox (1964), the transformation is estimated to enhance the normality of the tranformed data. We investigate the asymptotic relative efficiency of the ordinary t-test versus t-test applied transformation introduced by Yeo and Johnson (1997) under Pitman local alternatives. The theoretical and simulation studies show that two-sample t-test using transformed date gives higher power than ordinary t-test for location-shift models.

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질화계 발광다이오드의 측면 형상화를 이용한 광 추출 효율 향상 (Improvement of Light Extraction Efficiency by Side Surface Texturing in Nitride-based Light-Emitting Diodes)

  • 장동현;심종인
    • 한국광학회:학술대회논문집
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    • pp.95-96
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    • 2008
  • We theoretically investigated the influence of side surface texturing on the light extraction efficiency in nitride-based light-emitting diodes (LEDs). The light extraction efficiency was expected as 1.2 times larger in a LED with textured surfaces compared to without ones.

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