• Title/Summary/Keyword: Reducing power

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Reducing Power Consumption of a Scheduling for Module Selection under the Time Constraint (시간 제약 조건하에서의 모듈 선택을 고려한 전력감소 스케쥴링)

  • 최지영;박남서;김희석
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.1153-1156
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    • 2003
  • In this paper, we present a reducing power consumption of a scheduling for module selection under the time constraint. Traditional high-level synthesis do not allow reuse of complex, realistic datapath component during the task of scheduling. On the other hand, the proposed scheduling of reducing power consumption is able to approach a productivity of the design the low power to reuse which given a library of user-defined datapath component and to share of resource sharing on the switching activity in a shared resource. Also, we are obtainable the optimal the scheduling result in experimental results of our approach various HLS benchmark environment using chaining and multi-cycling in the scheduling techniques..

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Power Factor Correction Improvement and Total Harmonic Distortion Reducing for Panel's Air-conditioner (패널용 에어컨의 역률 개선 및 고조파 저감)

  • Park, S.W.;Park, J.W.;Lee, H.W.
    • Proceedings of the KIEE Conference
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    • 2001.10a
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    • pp.258-261
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    • 2001
  • High Power factor Active Filter converter is used for Inverter Air conditioner power supply to meet IEC standard. In the active filter topology for power factor, extra switch just control the input current indirectly to meet the IEC standard for reducing the cost and size. In this paper, low cost converter was suggested by simulation using extra switch which auxiliary pulse is inserted and quasi resonant soft switching topology control is adapted for panel's inverter air conditioner converter Inserting auxiliary Pulse method to the extra switch has the benefit of reducing THD by low cost input control circuit. And also quasi resonant soft switching topology can reduce switching loss. So both technical is suitable for Panel's Air conditioner.

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Reducing Current Distortion in Indirect Matrix Converters Operating in Boost Mode under Unbalanced Input Conditions

  • Choi, Dongho;Bak, Yeongsu;Lee, Kyo-Beum
    • Journal of Power Electronics
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    • v.19 no.5
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    • pp.1142-1152
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    • 2019
  • This paper presents a control method for reducing the current distortion in an indirect matrix converter (IMC) operating in boost mode under unbalanced input conditions. IMCs operating in boost mode are useful in distributed generation (DG) systems. They are connected with renewable energy systems (RESs) and the grid to transmit the power generated by the RES. However, under unbalanced voltage conditions of the RES, which is connected with the input stage of the IMC operating in boost mode, the input-output currents are distorted. In particular, the output current distortions cause a ripple of the power, which is transferred to the grid. This aggravates the reliability and stability of the DG system. Therefore, in this paper, a control method using positive/negative sequence voltages and currents is proposed for reducing the current distortion of both side in IMCs operating in boost mode. Simulation and experimental results have been presented to validate effectiveness of the proposed control method.

Antioxidant Activity on Ethanol Extract from Boiled-water of Hizikia fusiformis (톳 자숙액 에탄올 추출물의 항산화 활성)

  • Park, Ki-Eui;Jang, Mi-Soon;Lim, Chi-Won;Kim, Yeon-Kye;Seo, Young-Wan;Park, Hee-Yeon
    • Applied Biological Chemistry
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    • v.48 no.4
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    • pp.435-439
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    • 2005
  • Antioxidant activity of the ethanol extract from boiled-water of Hizikia fusiformis (EBH) were compared with those of BHA, L-ascorbic acid, gallic acid, caffeic acid and (-)-catechin. The free radical scavenging ability against DPPH (1,1-diphenyl-2-picrylhydrazyl), authentic peroxynitrite and reducing power were measured as indices of antioxidant activity. EBH showed the potent DPPH radical and peroxynitrite scavenging activities, showing 85.23 and 96.97% at final concentration of $1000{\mu}g/ml$, respectively. The reducing power increased with the increasing amount of EBH (final concentration of 1, 10, 100 and $1000{\mu}g/ml$). Total phenolic content of EBH was 588 mg (-)-catechin/g at the final concentration $1000{\mu}g/ml$. Total phenolic contents correlated with DPPH radical scavenging activity $(R^2=0.766)$ and reducing power $(R^2=0.944)$. These results suggested that EBH could be a natural antioxidative source containing antioxidative components.

Antioxidant Activities of n-Butanol and Ethyl Acetate Extracts from Yam (Dioscorea batatas DECNE.)

  • Duan, Yishan;Kim, Gyeong-Hwuii;Seong, Jong-Hwan;Chung, Hun-Sik;Kim, Han-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.4
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    • pp.599-606
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    • 2015
  • This study aimed at evaluating the antioxidant activity of raw yam (Dioscorea batatas $D_{ECNE.}$) extracted by n-butanol and ethyl acetate. The antioxidant activities, including ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were studied in vitro. Results showed ethyl acetate extract ($111.88{\pm}0.66mg\;CAE/g$) possessed higher total phenol content than n-butanol extract ($78.68{\pm}0.58mg\;CAE/g$). Ethyl acetate extract exhibited stronger antioxidant activity compared with n-butanol extract apart from reducing power assay.

An Effect of Roof-Fairing and Deflector System on the Reduction of Aerodynamic Drag of a Heavy-Duty Truck (대형트럭용 루프 훼어링과 디프렉트의 공기저항력 저감 특성에 관한 연구)

  • Kim, Chul-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.194-201
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    • 2006
  • Roof-fairing and deflector system have been used on heavy-duty trucks to minimize aerodynamic drag force not only for driving stability of the truck but also for energy saving by reducing the required driving power of the vehicle. In this study, a numerical simulation was carried out to see aerodynamic effect of the drag reducing device on the model vehicle. Drag and lift force generated on the five different models of the drag reducing system were calculated and compared them each other to see which type of device is efficient on the reduction of driving power of the vehicles quantitatively. An experiment has been done to see airflow characteristics on the model vehicles. Airflow patterns around the model vehicles were visualized by smoke generation method to compare the complexity of airflow around drag reducing device. From the results, the deflector systems(Model 5,6) were revealed as a better device for reduction of aerodynamic drag than the roof-fairing systems(Model 2,3,4) on the heavy-duty truck and it can be expected that over 10% of brake power of an engine can be saved on a tractor-trailer by the aerodynamic drag reducing device at normal speed range($80km/h{\sim}$).

Method and implementation for reducing stand by power consumption in SMPS with low-speedy power line communication (저속 전력선통신 적용 전원공급장치의 대기전력 절감 방법 및 구현)

  • Kim, Ki-Hyun;Son, Do-Sun;Kim, Hyoung-Woo;Seo, Kil-Soo;Kim, Sang-Cheol
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.1139-1140
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    • 2008
  • This paper is designated to introduce the method of reducing stand-by Power of SMPS applied PLC(Power Line Communication) and its implementation. PLC modem consists mainly of PLC Module, Coupling Circuit, ZCP(Zero-Cross Point) Circuit and Power Supply Circuit. By controlling power from Power Supply Circuit to PLC Module and ZCP Circuit, the reduction of Stand-by Power is established. When this method is applied to SMPS used for a low-speed PLC, about 50% power reduction is provided, compared to the other case to which it is not applied.

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Enrichment of $CO_2$-Fixing Bacteria in Cylinder-Type Electrochemical Bioreactor with Built-In Anode Compartment

  • Jeon, Bo-Young;Jung, Il-Lae;Park, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.21 no.6
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    • pp.590-598
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    • 2011
  • Bacterial assimilation of $CO_2$ into stable biomolecules using electrochemical reducing power may be an effective method to reduce atmospheric $CO_2$ without fossil fuel combustion. For the enrichment of the $CO_2$-fixing bacteria using electrochemical reducing power as an energy source, a cylinder-type electrochemical bioreactor with a built-in anode compartment was developed. A graphite felt cathode modified with neutral red (NR-graphite cathode) was used as a solid electron mediator to induce bacterial cells to fix $CO_2$ using electrochemical reducing power. Bacterial $CO_2$ consumption was calculated based on the variation in the ratio of $CO_2$ to $N_2$ in the gas reservoir. $CO_2$ consumed by the bacteria grown in the electrochemical bioreactor (2,000 ml) reached a maximum of approximately 1,500 ml per week. Time-coursed variations in the bacterial community grown with the electrochemical reducing power and $CO_2$ in the mineral-based medium were analyzed via temperature gradient gel electrophoresis (TGGE) of the 16S rDNA variable region. Some of the bacterial community constituents noted at the initial time disappeared completely, but some of them observed as DNA signs at the initial time were clearly enriched in the electrochemical bioreactor during 24 weeks of incubation. Finally, Alcaligenes sp. and Achromobacter sp., which are capable of autotrophically fixing $CO_2$, were enriched to major constituents of the bacterial community in the electrochemical bioreactor.

Reducing Power Consumption of a Scheduling Algorithm for Optimal Selection of Supply Voltage under the Time Constraint (시간 제약 조건하에서의 최적 선택 공급 전압을 위한 전력 감소 스케줄링)

  • 최지영;김희석
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.11C
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    • pp.1132-1138
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    • 2002
  • This paper proposes a reducing power consumption of a scheduling algorithm for optimal selection of supply voltage. In scheduling of reduction power consumption, we determine the control steps of operations to be executed by exploiting the possibility of using variable voltage levels to reduce power consumption. In the optimal selection of supply voltage binding, we minimize the main factor of the power consumption of the switching activity on the registers using a graph coloring technique. From a set of experiments using high-level benchmark examples, we show that the proposed algorithm prefer to use optimal selection supply voltages rather than uniformed single voltage is effective in reducing power consumption.

New Drowsy Cashing Method by Using Way-Line Prediction Unit for Low Power Cache (저전력 캐쉬를 위한 웨이-라인 예측 유닛을 이용한 새로운 드로시 캐싱 기법)

  • Lee, Jung-Hoon
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.10 no.2
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    • pp.74-79
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    • 2011
  • The goal of this research is to reduce dynamic and static power consumption for a low power cache system. The proposed cache can achieve a low power consumption by using a drowsy and a way prediction mechanism. For reducing the static power, the drowsy technique is used at 4-way set associative cache. And for reducing the dynamic energy, one among four ways is selectively accessed on the basis of information in the Way-Line Prediction Unit (WLPU). This prediction mechanism does not introduce any additional delay though prediction misses are occurred. The WLPU can effectively reduce the performance overhead of the conventional drowsy caching by waking only a drowsy cache line and one way in advance. Our results show that the proposed cache can reduce the power consumption by about 40% compared with the 4-way drowsy cache.

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