• Title, Summary, Keyword: Expected efficiency

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A Study on Thermodynamic Efficiency for HTSE Hydrogen and Synthesis Gas Production System using Nuclear Plant (원자력 이용 고체산화물 고온전기분해 수소 및 합성가스 생산시스템의 열역학적 효율 분석 연구)

  • Yoon, Duk-Joo;Koh, Jae-Hwa
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.5
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    • pp.416-423
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    • 2009
  • High-temperature steam electrolysis (HTSE) using solid oxide cell is a challenging method for highly efficient large-scale hydrogen production as a reversible process of solid oxide fuel cell (SOFC). The overall efficiency of the HTSE hydrogen and synthesis gas production system was analyzed thermo-electrochemically. A thermo-electrochemical model for the hydrogen and synthesis gas production system with solid oxide electrolysis cell (SOEC) and very high temperature gas-cooled reactor (VHTR) was established. Sensitivity analyses with regard to the system were performed to investigate the quantitative effects of key parameters on the overall efficiency of the production system. The overall efficiency with SOEC and VHTR was expected to reach a maximum of 58% for the hydrogen production system and to 62% for synthesis gas production system by improving electrical efficiency, steam utilization rate, waste heat recovery rate, electrolysis efficiency, and thermal efficiency. Therefore, overall efficiency of the synthesis production system has higher efficiency than that of the hydrogen production system.

Influence of Operating Conditions on the Performance of a Oxy-fuel Combustion Reference Cycle (순산소 연소 기본 사이클의 작동조건 변화에 따른 성능해석)

  • Park, Byung-Chul;Sohn, Jeong-Lak;Kim, Tong-Seop;Ahn, Kook-Young;Kang, Shin-Hyoung
    • Proceedings of the KSME Conference
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    • pp.2971-2976
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    • 2008
  • Recently, there has been growing interest in the oxyfuel combustion cycle since it enables high-purity CO2 capture with high efficiency. However, the oxyfuel combustion cycle has some important issues regarding to its performance such as the requirement of water recirculation to decrease a turbine inlet temperature and proper combustion pressure to enhance cycle efficiency. The purpose of the present study is to analyze performance characteristics of the oxyfuel combustion cycle with different turbine inlet temperatures and combustion pressures. It is expected that the turbine inlet temperature improves cycle efficiency, on the other hand, the combustion pressure has specific value to display highest cycle efficiency.

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A Study on Efficiency for the Department of Trade in Universities

  • Park, Hyun-Chae;Kang, In-Kyu
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.52
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    • pp.97-118
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    • 2011
  • 85% of South Korea's gross domestic product(GDP) depends on trade. Exports amount in 2011 exceeds $ 5,000Billion. Korea is expected to achieve $ 1 trillion in total trade volume and will become finally the ninth in the world. We do not have a lot of natural resources and are bound to export the finished products to pursue economic development. In other words, trade sector is very essential for Korea to continue economic growth. The department of trade in universities have brought up the concerned students serving for trade sectors. Currently, "half-price tuition" in universities has become very controversial issue in Korea so this paper studies the efficiency of "the Department" because the universities may reconsider the adjustment of tuition fee, if they can enhance the efficiency level. DEA model is used for the analysis. As a result, 8 DMUs like KAN1, KEI5, BAE10 etc. show relatively higher efficiency levels.

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A Study on Training of Specialist to prepare Mandatory Building Energy Efficiency Rating Ssytem (건축물 에너지효율등급 인증제도 의무화 대비 전문인력 양성에 대한 연구)

  • Jang, Cheol-Yong;Han, Hye-Sim;Lee, Na-Eun
    • 한국태양에너지학회:학술대회논문집
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    • pp.138-143
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    • 2011
  • Until now, measures for energy saving in buildings have been tried. Because particularly the role of buildings area is very important for implementing national greenhouse gas reduction targets and Green growth. But, lack of business linkages between each sector or the interest and participation of private sector are not enough. In addition, relevant personnel to do had not been systematized. It is expected that certification services will be increased according to the activation of Building Energy Efficiency Rating System and expansion of the target buildings so Government must be prepared to expand of certification system by training Professional staff. In this study, the basic data for the introduction of obligation of Building Energy Efficiency Rating System is suggested through analysis of the operating and laws system of Building Energy Efficiency Rating System along with efforts of Government for diffusion low energy buildings.

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The Maximum Efficiency Driving in IPMSM by Precise Estimation of Current Phase Angle

  • Cho, Gyu-Won;Kim, Cheol-Min;Kim, Gyu-Tak
    • Journal of Electrical Engineering and Technology
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    • v.8 no.5
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    • pp.1221-1226
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    • 2013
  • In this paper, the equivalent circuit for the efficiency calculation by precise estimation of the linkage flux, inductance and iron loss resistance was calculated accurately. In addition, the driving characteristics according to the current phase angle are analyzed and the maximum efficiency point is calculated. And then, analyzed and experimental values of the efficiency were compared. So, causes of error were expected to be vibration and noise by harmonic distortion of the voltage and current, and mechanical loss of dynamometer. In addition, the driving characteristics according to the current phase angle are analyzed and the maximum efficiency point is calculated.

Analysis of the Efficiency According to Resonant Repeater Application in Magnetic Resonant Wireless Power Transfer System (자기공진방식의 무선전력전송 시스템에서 공진 중계기 적용 여부에 따른 전력전송 효율 분석)

  • Baek, Seung-Myung;Kim, Dong-Eun;Shon, Jin-Geun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.67 no.4
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    • pp.221-226
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    • 2018
  • In this paper, the power transfer efficiency analysis based on the resonant repeater in a magnetic resonance wireless power transfer system is proposed. The efficiency of the magnetic resonance method was verified by comparing the general frequency with the resonance frequency. The resonance repeater was arranged to increase the efficiency and increase the transfer distance. When using resonant repeaters, the maximum efficiency increase is about 36.23[%] and the transfer distance was extended to more than 20[cm]. Through this study, confirmed the effect of using resonance repeaters in wireless power transfer system. As a result, it can be expected that the overall technology related to wireless power transfer system will be more valuable for energy-IT technology.

Study of Character Animation to improve Production Efficiency

  • Choi, Chulyoung
    • International journal of advanced smart convergence
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    • v.9 no.2
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    • pp.179-184
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    • 2020
  • Recently, webtoons-based animations have been expanding in Korea, where the role of mobile devices is growing, and media videos such as "YouTube" and "Tik-Tok," which have shorter screening and production cycles than traditional feature films, dramas, and animations, are attracting attention and being enjoyed by public. In order to produce animation content that fits the trend of this shortening video and production cycle, efficiency must be increased not only in story but also in production. Production methods and production technologies need changes to increase efficiency. Animation using motion capture, which is highly production-efficient, is widely used in movies that shows realistic movements, but still has little use in producing cartoon-style animations with exaggerated movements. We analyzed the production method of 2D animation and CG animation and applied the result to CG animation to increase the efficiency of production and production. The methods of production through such experiments are expected to help improve the efficiency of producing animation content that is suitable for the latest trends such as webtoon animation.

Structure and Characteristics of Tandem Solar Cell Composed of Dye-sensitized Solar Cell and Thermoelectric Generator (염료감응형 태양전지와 열전발전소자를 결합한 복합 태양전지의 구조 및 특성)

  • Lee, Dong-Yoon;Song, Jae-Sung;Lee, Won-Jae;Kim, In-Sung;Jeong, Soon-Jong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.4
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    • pp.357-362
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    • 2005
  • The tandem solar cell composed of a dye-sensitized solar cell (DSC) and a thermoelectric generator (TEG) was designed. In such new cell, the characteristics of DSC and TEG were investigated. DSC uses the wavelength range of 380∼750 nm and has the maximum efficiency of below 10 %. If the solar light transmitted through DSC can be converted to heat energy, TEG can generate electric energy using this heat energy. By this means, it is possible to utilize most of solar energy in the wavelength range of 350∼3000 nm for electric generation and it can be expected to obtain higher solar energy conversion efficiency exceeding the known limit of maximum efficiency. For this purpose we suggest the tandem solar cell constructed with DSC and TEG. In this structure, DSC has a carbon nanotube film as a counter electrode of DSC in order to collect the solar light and convert it to heat energy. We measured the I-V characteristics of DSC and TEG, assembled to the tandem cell. As a result, it was shown that DSC with carbon nanotube and TEG had the efficiency of 9.1 % and 6.2 %, respectively. From this results, it is expected that the tandem solar cell of the new design has the possibility of enhanced conversion efficiency to exceed above 15 %.

Determinants of Commercial Banks' Efficiency in Bangladesh: Does Crisis Matter?

  • Banna, Hasanul;Ahmad, Rubi;Koh, Eric H.Y.
    • The Journal of Asian Finance, Economics and Business
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    • v.4 no.3
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    • pp.19-26
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    • 2017
  • Banks play a crucial role in bringing stability and economic development through their expected contribution in proper financial resource mobilisation across the economy. Despite the importance, there is little focus in recent literature which provided the empirical evidence how the global financial crisis affect the bank efficiency in Bangladesh. Thus, this paper aims to examine the effect of the global financial crisis and other factors on the efficiency of Bangladesh commercial banks. By employing the Data Envelopment Analysis (DEA) method, we computed the technical efficiency of individual banks operating in the Bangladesh banking sector during 2000 to 2013. The empirical findings indicate that the Bangladesh banking sector has exhibited the highest efficiency level during 2001, while efficiency seems to be at the lowest level during 2010. The study finds that crisis along with bank size, capital adequacy ratio, return on average equity and real interest rate have a significant effect on bank efficiency in Bangladesh. In order to keep the sound financial development of Bangladesh, banks operating in the Bangladesh banking sector have to consider all the potential technologies which could improve their profit efficiency levels, since the main motive of banks is to maximise shareholders' value or wealth through profit maximisation.

A Study on Analyzing Innovation Efficiency in Service Sector of Korea (우리나라 서비스부문의 혁신효율성 분석에 관한 연구)

  • Choi, Joung-In;Gwon, Seong-Hoon;Song, Sung-Hwan;Hwang, Seog-Won
    • IE interfaces
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    • v.22 no.4
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    • pp.336-346
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    • 2009
  • One of primary assumptions on DEA is that all DMUs for evaluation should be homogeneous. In comparative analysis among DMUs with relative efficiency measurement, it should be evaluated under identical conditions by ruling out external environmental influences. In this study, a measurement of innovation efficiency using the three-stage approach is performed. The approach employs DEA to measure relative efficiency and Tobit regressions to control external variables affecting innovation activity. The approach applied to firms in Korean Innovation Survey: Service Sector 2003 and 2006. Final efficiency scores of the approach represent net efficiency of the innovation. This study found that there is a increasing on technical efficiency of third stage, and it has difference with first stage significantly. Besides, a decrease on standard deviation of third stage is found. It means DMUs biased lower due to unfavorable condition and ones biased higher due to favorable condition are fallen into an identical operating environment through the approach. A measurement of net efficiency, excluding external effects, ensures the homogeneity of DMUs so that improves the reliability in terms of its analysis results. This study is expected to provide a direction and to be a valuable reference to further evaluation of innovation performance in Korean service sector.