• Title/Summary/Keyword: Effiency

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Analysis of the Characteristics of Single-Phase Induction motors and Improved Effiency Design (단상유도전동기의 특성해석 및 효율향상 설계)

  • Ryu, Ho-Gil;Nam, Hyuk;Jeong, Seung-Kyu;Hong, Jung-Pyo
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.870-872
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    • 2003
  • This paper deals with the characteristic analysis of capacitor-run single phase induction motor by equivalent circuit. The unbalanced elliptic rotating magnetic field of the motor was analysed by the symmetrical coordinate method. And this paper check the reliability of characteristic analysis by equivalent circuit in comparison with experimental results and analyse the characteristics of single phase induction motors by changing circuit parameters. Finally, this paper shows the improved effiency design motor by using that result.

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Integrated Safety, Quality, and Environment Information System Based on Web Environment (웹 기반 하에서의 안전, 품질, 환경 통합 정보 시스템)

  • 박재현;김형준;나승훈;서지한;김귀남
    • Proceedings of the Safety Management and Science Conference
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    • 2000.05a
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    • pp.27-32
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    • 2000
  • This study presents the design of integrated safety, quality, and environmental information system based on the internet environment. Quality management system, environmental management system, and safety management system are adapted in many manufacturing and service organization respectively but those system does not work effectively. Especially safety management system and environmental management system are very similar with format and contents. Therefore, Those system must be integrated to increase effiency.

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An Ergonomic Design of Brake and Accelerator Pedal Placement for Korean Driver (자동차 브레이크 페달 배치의 인간공학적 설계)

  • 김유창
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.106-109
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    • 1995
  • Optimum relocation of the brake relative to the accelerator can reduce stopping diatance and may mean the difference between an accident and a near-accident. A driving simulator was used to examine effiency of brake time. Brake time was measured for 30 participants in six conditions. Brake times were shown to improve as a result of moving the brake pedal from its typical heights above the accelerator to positions below the accelerator.

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Global Trends in Efficiency Regulation of Motor System (전동기 시스템의 효율 규제에 관한 국제 동향)

  • Jang, Kibong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.10
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    • pp.1298-1302
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    • 2018
  • Minimum Efficiency Performance Standard (MEPS) has already been operated in many countries. In particular, the European Union (EU) has entered the IE3 stage since 2017. Korea will also enter the IE3 phase from October 2018. As for Korea, there is still a restriction on induction motors only. But, in the EU and the United States, efficiency regulation of variable speed drives is being deeply examined. Standards related to this are gradually being fixed. In this paper, the current status and the direction of global standards related to the efficiency of motors, inverters and systems are reviewed. And the case of improving the efficiency of the system including the motor will be examined.

The Effect of Electric Vehicle on Power System and related Policies (전기자동차의 보급정책과 전력계통에 대한 영향)

  • Lee, Geun-Joon;Han, Sung-Ho;Lee, Hyun-Chul;Yoon, Yong-Bum
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.44_46
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    • 2009
  • Becoming effective on Kyoto protocol, reduction of greenhouse gas is an urgent concern of our world. Transportation, depending on fossil fuel, is required to transfer higher effiency and green tech. oriented one. Electric Vehicle-EV-is take attention with its ability not only to reduce CO2 emission in transportation, but also to support load levelizing, spinning reserve, increase power quality on microgrid. This paper presents the recent policy for EV diffusion and the effects on power system demand and local system power quality.

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An Analysis of Surface irrigation's Hydraulic Characteristics at a Paddy Field Using a Two-Dimensional Numerical Model (2차원 유한체적 수치모형을 이용한 논의 지표관개 수리특성 분석)

  • Park, Seung-Woo;Park, Jong-Min;Kang, Min-Goo
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.4
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    • pp.3-11
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    • 2004
  • A finite volume model is developed to simulate the surface irrigation at a paddy field. The model's capabilities are validated through comparison with the simulafed results and the observed data obtained by various experimental tests, and the simulated results are in good agreement with the observed pending depth. The result of surface irrigation simulation shows that the longer the paddy field's the length of long-sided becomes, the longer the advance and storage time is taken. To analyze surface irrigation performance with variable inflow rate, three patterns of flow variation-constant rate, initially high then low, and initially low then high-were studied. The results show that at the pattern with initially high followed by low during the latter half of the irrigation the advance time is shortest, but the pending depth of irrigation completion and irrigation effiency are the little difference between irrigation patterns.

Effect of Process Variables on NOx Removal by Low Temperature Plasma Process (저온 플라즈마 공정에 의한 NOx 제거시 공정 변수의 영향)

  • Park, Jung-Hwan;Kim, Dong-Joo;Kim, Kyo-Seon
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.279-284
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    • 2001
  • In this study, we analyzed the $NO_X$ removal effiency by the low temperature plasma process and investigated the effect of several process variables. Most of NO is converted into $NO_2$ and, later, into $HNO_3$ which reacts with $NH_3$ to form $NH_4NO_3$ particles. As the frequency of appling voltage increases, as the applied voltage increases or as the residential time increases, removal efficiency of the NO supplied initially increase. The removal efficiency of $NO_X$ also increases with the increase of $NH_3$ supplied.

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Numerical Analysis of A Vortex Cyclone in A Recirculating Aquaculture System (순환여과 양식장에서 와류형 분리기에 대한 수치적 검토)

  • Jeong, S.K.;Kim, E.
    • Journal of Power System Engineering
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    • v.9 no.1
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    • pp.36-41
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    • 2005
  • This study investigated the performance of a vortex hydrocyclone for solid removal in a recirculating aquaculture system. In a fish-breeding industry, effluent water is mainly disposed by gravity sedimentation. Thus, a large settling tank and a lot of water are needed to purify effluent water. However, this typical method does not show consistent efficiency. In case of low efficiency, discharged water contains a lot of feeding sediments. This causes environmental problems. Instead of this typical method a hydrocylone is tested to discharge water which contains a lot of feeding sediments. In this paper, a hydrocyclone with low velocity and pressure drop in a recirculating aquaculture system is investigated.

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Efficiency Improvement of Polycrystalline Silicon Solar Cells using a Grain boundary treatment (결정입계 처리에 따른 다결정 실리콘 태양전지의 효율 향상)

  • 김상수;김재문;임동건;김광호;원충연;이준신
    • Electrical & Electronic Materials
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    • v.10 no.10
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    • pp.1034-1040
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    • 1997
  • A solar cell conversion effiency was degraded by grain boundary effect in polycrystalline silicon. Grain boundaries acted as potential barriers as well as recombination centers for the photo-generated carriers. To reduce these effects of the grain boundaries we investigated various influencing factors such as emitter thickness thermal treatment preferential chemical etching of grain boundaries grid design contact metal and top metallization along boundaries. Pretreatment in $N_2$atmosphere and gettering by POCl$_3$and Al were performed to obtain multicrystalline silicon of the reduced defect density. Structural electrical and optical properties of slar cells were characterized before and after each fabrication process. Improved conversion efficiencies of solar cell were obtained by a combination of pretreatment above 90$0^{\circ}C$ emitter layer of 0.43${\mu}{\textrm}{m}$ Al diffusion in to grain boundaries on rear side fine grid finger top Yb metal and buried contact metallization along grain boundaries.

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Fabrication and Characterization of Polycrystalline Silicon Solar Cells using Preferential Etching of Grain Boundaries (결정입계의 선택적 식각을 이용한 다결정 규소 태양전지의 제작과 특성)

  • Kim, Sang-Su;Kim, Cheol-Su;Lim, Dong-Gun;Kim, Do-Young;Yi, Jun-Sin
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1430-1432
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    • 1997
  • A solar cell conversion effiency was degraded by grain boundary effect in polycrystalline silicon. To reduce these effects of the grain boundaries, we investigated various influencing factors such as preferential chemical etching of grain boundaries, grid design, transparent conductive thin film, and top metallization along grain boundaries. Pretreatment in $N_2$ atmosphere and gettering by $POCl_3$ and Al were performed to obtain polycrystalline silicon of the reduced defect density. Structural, electrical, and optical properties of solar cells were characterized. Improved conversion efficiencies of solar cell were obtained by a combination of Al diffusion into grain boundaries on rear side, fine grid finger, top Yb metal grid on Cr thin film of $200{\AA}$ and buried contact metallization along grain boundaries.

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