• 제목/요약/키워드: Efficiency Measure

검색결과 1,634건 처리시간 0.027초

소형 직류모터의 간략한 효율예측에 관한 연구 (A Study on a Simple Efficiency Estimation of Small DC Motor)

  • 원성홍
    • 전기학회논문지P
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    • 제63권3호
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    • pp.143-148
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    • 2014
  • This paper proposes a novel efficiency measurement method without dynamometer. In case of small motor, the measurement of efficiency is not easy because the percentage of mechanical loss is comparably huge and the mechanical loss is not easy to be measured. In this paper, the authors proposes a method which can measure the efficiency with two test motors. This method can be useful to engineers who study small electrical motors.

An Analysis of Vietnamese Bank Productivity Change in the Time of Restructuring

  • TO, Tha Hien;LE, Phuong Thanh
    • The Journal of Asian Finance, Economics and Business
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    • 제7권11호
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    • pp.779-788
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    • 2020
  • Commercial banks play an important role as the main source of funding in the transition process of Vietnam as a market economy. As a result, enhancing the efficiency and productivity of Vietnamese banks can decrease the lending cost for individuals and enterprises. This study is to measure and analyze the productivity change of Vietnamese banking system in different ownership cohorts and sources of this change during the period of restructuring (2011-2019). The Hicks-Moorsteen total factor productivity index is utilised to measure the productivity change and to identify the sources of this change. For an empirical analysis, the data of 28 Vietnamese commercial banks from 2011 to 2018 is collected from their financial statements including balance sheets and income statements. The results show an increase of Vietnamese bank productivity due to the technological progress. While foreign and joint-venture banks are the most advanced cohort, state-owned banks have the lowest rate of productivity growth. The restructuring program negatively impacts scale efficiency and this measure attributes to a decline in the overall efficiency of the banks. We also found that state-owned commercial banks are the most efficient group in the sense that they can achieve the maximal level of revenue from a given amount of expense.

우리나라 RCC/RSC별 운영효율성 분석 (An Analysis of Technical Efficiency in Korean RCC/RSC)

  • 장운재;금종수
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2004년도 추계학술대회
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    • pp.191-196
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    • 2004
  • 본 연구는 우리나라 RCC/RSC의 효율성을 전체 기술적 효율성, 순수 기술적 효율성과 규모의 효율성으로 구분하여 측정 평가하였다. RCC/RSC의 전체 기술적 효율성은 평균 $91.03\%$ 수준이었으며, 순수 기술적 효율성은 $96.80\%$로 나타났고 규모의 효율성은 $93.83\%$로 전체 기술적 비효율성이 가장 높게 나타났으며 이것은 생산규모에 따른 비효율성보다는 자원의 비효율적인 운영에 따른 효율성에 큰 문제가 있는 것으로 판단된다. 또한 규모에 대한 수익체감은 통영RSC, 수익체증은 인천, 태안, 군산, 여수, 울산, 동해 등의 RCC/RSC로 나타났다. 그리고 비효율적인 RCC/RSC는 준거집단을 참조하여 벤치마킹올 해야 한다.

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부원료검정 robot system 구축 (Construction of the submaterials sampling robot system)

  • 김상문
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1288-1291
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    • 1996
  • The submaterials are used for restoration of the impurities involved in iron ore. Robot system is constructed to measure the content of moisture in submaterials automatically, so we achieve the confidence of measuring work and the promotion of operation efficiency.

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분류모형과 DEA를 이용한 두뇌한국(BK) 21 사업단 효율성 분석 (Data Envelopment Analysis and Logistic Model for BRAIN KOREA 21)

  • 손소영;주용규
    • 산업공학
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    • 제17권3호
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    • pp.249-260
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    • 2004
  • The objective of this study is to measure and to predict the efficiency of participating groups of BK 21 by using DEA. DEA is a methodology to measure and to evaluate the relative efficiency of a homogeneous set of decision-making units (DMUs) in a process which uses multiple inputs to produce multiple outputs. In order to reflect the effect of the environmental factors of BK 21, we consider not only a general DEA model but also a logistic model for DEA. As a result, location of participating groups of BK 21 turns out to be significant. Our proposed approach can predict the efficiency of a new BK 21 group with given environmental factors. It is expected that these models can give a feedback for effective management of BK 21.

메탈 화이버 버너에서의 연소 특성 및 복사 효율에 관한 실험적 연구 (A Study on the Combustion Characteristics and Radiation Efficiency of Metal Fiber Burners)

  • 박주원;정태용;신동훈
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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    • pp.13-18
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    • 2006
  • Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. High radiation efficiency is one of the most important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.

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메탈 화이버 버너에서의 연소 특성 및 복사 효율에 관한 실험적 연구 (A Study on the Combustion Characteristics and Radiation Efficiency of Metal Fiber Burners)

  • 박주원;정태용;신동훈
    • 한국연소학회지
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    • 제11권1호
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    • pp.27-33
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    • 2006
  • Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. Radiation efficiency is one of the important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.

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RCC/RSC별 운영 효율성 분석 (An Analysis of Technical Efficiency in the Korean RCC/RSC)

  • 금종수;장운재
    • 한국항해항만학회지
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    • 제29권3호
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    • pp.215-220
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    • 2005
  • 본 연구는 우리나라 RCC/RSC의 효율성은 전체 기술적 효율성, 순수 기술적 효율성과 규모의 효율성으로 구분하여 측정 평가하였다. RCC/RSC의 전체 기술적 효율성은 평균 $91.03{\%}$ 수준이었으며, 순수 기술적 효율성은 $96.80{\%}$로 나타났고 규모의 효율성은 $93.83{\%}$로 전체 기술적 비효율성이 가장 높게 나타났으며 이것은 생산규모에 따른 비효율성보다는 자원의 비효율적인 운영에 따른 효율성에 큰 문제가 있는 것으로 판단된다. 또한 규모에 대한 수익체감은 통영RSC, 수익체증은 인천, 태안, 군산, 여수, 울산, 동해 등의 RCC/RSC로 나타났다. 따라서 효율성이 낮은 RCC/RSC는 효율성이 높은 준거집단을 참조하여 벤치마킹을 해야 한다.

디젤차량 연비시험에 있어 시험온도 및 냉각팬 조건이 미치는 영향분석에 관한 연구 (A Study on the Influence of Test Temperature & Cooling Fan Condition on the Fuel Test of Diesel Vehicle)

  • 김현진;김성우;임재혁;노경하;이정천;김기호;오상기
    • 동력기계공학회지
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    • 제21권6호
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    • pp.46-55
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    • 2017
  • Due to the arise of natural disasters caused by global warming, consumers have more interest in the fuel efficiency of their vehicles, and fuel efficiency became an important factor in comparing vehicles. In this market situation, methods to measure fuel efficiency has become one of the main interests of vehicle related organizations and laboratories, and the current method to measure fuel efficiency is to follow the notification established by the ministry of trade, industry and energy, ministry of environment, and the ministry of land, infrastructure and transport. In this study, we analyze the influence of vehicle fuel efficiency according to test temperature and cooling fan condition which have the possibility to cause difference in fuel efficiency. The analysis results of the influence of the fuel efficiency according to the test temperature, the difference of the fuel efficiency of the test temperature ($21{\sim}29^{\circ}C$) within the allowable range of the notification showed a maximum difference of 2.9%. Therefore, it is necessary to consider the introduction of a test method that permits only the temperature change based on the reference point as the allowable range even in the test within the allowable range. The analysis of the influence of the fuel efficiency according to the cooling method showed no significant effect, and it seems reasonable to maintain the test method of the current notification.

원통기어의 다단면 치형 측정평가 (The Evaluation of Cylindrical Gear Measurement on Teeth Roots and Bottom Profiles in Different Sections)

  • 문성민;강재화;키도히로미쯔;구로가와슈헤이;류성기
    • 한국기계가공학회지
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    • 제11권1호
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    • pp.46-49
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    • 2012
  • Gears are reliable and efficient power transmission elements. They have been widely used in all kinds of machinery. Nowadays, resource conservation energy conservation environmental improvements from the request of the compact, light weight, high efficiency, low cost Higher efficiency is required. Tooth root and bottom profiles of cylindrical gears affect bending fatigue life, but they are hard to measure with conventional gear measuring machine(GMM), because GMM is normally customized to measure only gear working flanks. The authors try to develop a new type of GMM by installing an extra 3D scanning probe and control software to measure tooth root and bottom profiles. First, in order to measure in various directions, a 3D scanning probe has been attached to the GMM developed. Next, calibration algorithm has been developed. Deviations of the calibration results are measured and it is found that systematic error must be caused by heat from driving motors. A new alternative GMM with driving motors generating less heat was designed and two GMMs are compared. Finally, 3 Dimension measurement of tooth root and bottom profiles of cylindrical gears is described.