• 제목/요약/키워드: Electronic Power Consumption

검색결과 797건 처리시간 0.034초

전기영동형 전자종이를 위한 $TiO_2$ 나노분말의 분산 제어 (A control dispersion of $TiO_2$ nano powder for electronic paper of electrophoresis)

  • 김중희;오효진;이남희;황종선;김선재
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.324-327
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    • 2005
  • An electrophoretic display using $TiO_2$ particles is the most promising candidate because it offers various advantages such as ink-on-paper appearance, good contrast ratio, wide viewing angle, image stability in the off-state and extremely low power consumption. The core technology of electrophoretic display is the dispersion controlling of $TiO_2$ nano particles in nonaqueous solution. To prepare an ink for electronic paper using electrophoretic properties of $TiO_2$ nano particles, cyclohexane with low dielectric constant and transparency, polyethylene for producing polymer coating layer which reduces apparent gravity of $TiO_2$, and $TiO_2$ powders were mixed together by planetary-mill. The zeta-potential value of $TiO_2$ particles in cyclohexane was measured about -40mV, but was measured over -110mV by dispersant attached to polyethylene-coated $TiO_2$ surface. Prepared electronic ink was filled in cross patterned micro-wall with $200{\mu}m$ in width and $40{\mu}m$ in height on ITO glass designed by photolithography. The response time of electronic paper evaluated by mobility of $TiO_2$ particle between micro-walls was measured 0.067sec, but the drift velocity from reflectance wave form during reverse from of electronic ink was measured 0.07cm/sec.

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열원 냉각용 루프 써모사이폰의 작동 특성 (Performance Characteristics of a Loop Thermosyphon for Heat Source Cooling)

  • 최두성;송태호
    • 대한기계학회논문집B
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    • 제28권12호
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    • pp.1475-1483
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    • 2004
  • Loop thermosyphon(LTS) has many good characteristics such as low thermal resistance, no power consumption, noiseless operation and small size. To investigate the overall performance of LTS, we have performed various experiments varying three parameters: input power of the heater, working fluid(water, ethanol, FC3283) and filling ratio of the working fluid. At a combination of these parameters, temperature measurements are made at many locations of the LTS. The temperature difference between the evaporator and the condenser is used to obtain the thermal resistance. In addition, flow visualization using a high speed camera is carried out. The thermal resistance is not constant. It is lower at higher input power, which is one of the distinct merits of LTS. Flow instabilities are frequently observed when changing the working fluid, the input power and the filling ratio. The results show that the LTS can be readily put into practical use. Future practical application in electronic cooling is recommended.

파워 어시스트 시스템을 위한 이동 머니퓰레이터의 제어 (Control of Mobile Manipulators for Power Assist Systems)

  • 이형기;성영휘;정명진
    • 대한전기학회논문지:시스템및제어부문D
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    • 제49권2호
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    • pp.74-80
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    • 2000
  • In this paper, we present a control method of mobile power assist systems. Most of mobile power assist systems have a heavy base for preventing easy tumbling, so continual movement of the base during operations causes high energy consumption and gives the high risk of human injury. Furthermore, the slow dynamics of the base limits the frequency bandwidth of the whole system. Thus we propose a cooperation control method of the mobile base and manipulator, which removes the unnecessary movements of the base. In our scheme, the mobile base does not move until the center of gravity(C.G) of the system goes outside a safety region. When C.G. reaches the boundary of the safety region, the base starts moving to recover the manipulator's initial configuration. By varying the parameters of a human impedance controller, the operator is warned by a force feedback that C.G. is on the marginal safety region. Our scheme is implemented by assigning a nonlinear mass-damper-spring impedance to the tip of the manipulator. Our scheme is implemented by a nonlinear mass-spring impedance to the tip of the manipulator. The experimental results show the efficacy of the proposed control method.

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데이터를 고려한 저전력 소모 CGRA 매핑 알고리즘 (Low Power Mapping Algorithm Considering Data Transfer Time for CGRA)

  • 김용주;윤종희;조두산;백윤흥
    • 정보처리학회논문지A
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    • 제19A권1호
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    • pp.17-22
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    • 2012
  • 모바일 시장 및 소형 전자기기 시장의 발달에 따라 고성능 프로세서에 대한 요구 또한 커지게 되었다. 재구성형 프로세서(CGRA)는 고성능과 저전력 소모를 동시에 만족시키는 프로세서로 ASIC의 고성능 저전력을 대체하면서도 하드웨어를 쉽게 재디자인 할 수 있도록 구성된 프로세서이다. 어플리케이션의 구조에 따라 CGRA의 전체수행시간이 프로세서 자체의 수행시간보다 데이터의 전송시간에 종속되는 경우가 있다. 이 논문에서는 데이터 전송시간에 따라 수행에 사용되는 자원을 최적화 함으로써 전력소모를 줄이는 매핑 알고리즘을 제안하였다. 제안된 알고리즘을 사용한 경우, 기존의 방식보다 최대 73%, 평균 56.4%의 전력소모를 줄일 수 있었다.

자동차 전장 시스템에서 주기 및 비주기 태스크를 위한 실시간 스케줄링 (Real-Time Scheduling for Periodic and Aperiodic Tasks on Automotive Electronic System)

  • 조수연;김남진;이은령;김재영;김주만
    • 대한임베디드공학회논문지
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    • 제6권2호
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    • pp.55-61
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    • 2011
  • We propose power-saving real-time scheduling method for mixed task sets which consist of both time-based periodic and event-based aperiodic tasks in the automotive operating system. In this system, we have to pursue maximization of power-saving using the slack time estimation and minimization of response time of aperiodic tasks simultaneously. However, since these two goals conflict each other, one has to make a compromise between them according to the given application domain. In this paper, we find the adjustment factor which gives better response time of aperiodic tasks with slight power consumption increase. The adjustment factor denotes the gravity of response time for aperiodic tasks. We apply the ccEDF scheduling for time-based periodic tasks and then calculate new utilization to be applied to the adjustment factor. In this paper, we suggest the lccEDF algorithm to make a tradeoff between the two goals by systematically adjusting the factor. Simulation results show that our approach is excellent for variety of task sets.

Joint Optimization for Residual Energy Maximization in Wireless Powered Mobile-Edge Computing Systems

  • Liu, Peng;Xu, Gaochao;Yang, Kun;Wang, Kezhi;Li, Yang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권12호
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    • pp.5614-5633
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    • 2018
  • Mobile Edge Computing (MEC) and Wireless Power Transfer (WPT) are both recognized as promising techniques, one is for solving the resource insufficient of mobile devices and the other is for powering the mobile device. Naturally, by integrating the two techniques, task will be capable of being executed by the harvested energy which makes it possible that less intrinsic energy consumption for task execution. However, this innovative integration is facing several challenges inevitably. In this paper, we aim at prolonging the battery life of mobile device for which we need to maximize the harvested energy and minimize the consumed energy simultaneously, which is formulated as residual energy maximization (REM) problem where the offloading ratio, energy harvesting time, CPU frequency and transmission power of mobile device are all considered as key factors. To this end, we jointly optimize the offloading ratio, energy harvesting time, CPU frequency and transmission power of mobile device to solve the REM problem. Furthermore, we propose an efficient convex optimization and sequential unconstrained minimization technique based combining method to solve the formulated multi-constrained nonlinear optimization problem. The result shows that our joint optimization outperforms the single optimization on REM problem. Besides, the proposed algorithm is more efficiency.

Development of DC Controller for Battery Control for Elevator Car

  • Lee, Sang-Hyun;Kim, Sangbum
    • International Journal of Internet, Broadcasting and Communication
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    • 제13권2호
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    • pp.103-111
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    • 2021
  • Among transport vehicles, Special Vehicles (SVs) are seriously exposed to energy and environmental problems. In particular, elevator cars used when moving objects in high-rise buildings increase the engine's rotational speed (radian per second: RPM). At this time, when the vehicle accelerates rapidly while idling, energy consumption increases explosively along with the engine speed, and a lot of soot is generated. The purpose of this paper is to develop a bi-directional DC-DC converter for control of vehicle power and secondary battery used in an elevated ladder vehicle (EC) used in the moving industry. As a result of this paper, the performance test of the converter was conducted. The charging/discharging state of the converter was simulated using DC power supply and DC electronic load, and a performance experiment was conducted to measure the input/output power of the converter through a power meter. Through this experimental result, it was confirmed that the efficiency was more than 92% in Buck mode and Boost mode at maximum 1.2kW output.

저전력 휴대 멀티미디어 SoC를 위한 H.264 디블록킹 필터 설계 (Design of H.264 Deblocking Filter for Low-Power Mobile Multimedia SoCs)

  • 구재일;이성수
    • 대한전자공학회논문지SD
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    • 제43권1호
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    • pp.79-84
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    • 2006
  • 본 논문에서는 저전력 휴대 멀티미디어 SoC를 위한 새로운 H.264 디블록킹 필터를 제안하였다. H.264 디블록킹 필터는 처리되는 화소값의 차이가 어떤 특정 조건을 만족하면 필터링의 일부 또는 전부를 수행하지 않아도 된다. 더욱이 양자화 계수값이 16 미만일 때에는 필터링 전체를 수행하지 않아도 된다. 이러한 특성을 이용하면 동작중에 디블록킹 필터 전체 또는 일부분을 가동 중단시킴으로서 전력 소모를 크게 줄일 수 있다. 제안하는 디블록킹 필터는 간단한 제어 회로를 사용하여 블록의 일부 또는 전부를 가동 중단시킬 수 있으며, 단일 하드웨어로 수평방향 필터링과 수직방향 필터링을 동시에 수행할 수 있다. 제안하는 저전력 디블록킹 필터는 $0.35{\mu}m$ 표준 셀 라이브러리 공정을 사용하여 실리콘 칩으로 구현되었다. 게이트 수는 약 20,000 게이트, 최대 동작 주파수는 108MHz, 최대 처리능력은 CCIR601 형식에서 30 frame/s이다.

선박용 변압기 없는 40W LED 조명 구동회로의 설계 및 구현 (Design and Implementation of Transformerless 40W LED Light Driver Circuit for Ships)

  • 송종관;박장식;윤병우
    • 한국전자통신학회논문지
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    • 제7권3호
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    • pp.485-490
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    • 2012
  • 본 논문에서는 선박의 진동에 의하여 수명이 짧은 필라멘트를 사용하는 조명기구를 대체하기 위하여 선박용 LED 조명등 구동회로를 설계 및 구현하였다. 구동회로는 부피를 줄이고 비용을 절감하기 위하여 변압기가 없는 스위칭 회로로 설계되었다. 스위칭 회로는 입력 교류전압 220 V에 PWM 제어를 함으로써 안정적으로 LED를 구동할 수 있도록 설계하였다. 스위칭 회로의 펄스성 전류에 대하여 Valley-fill 방식의 역률 보상회로를 채용함으로써 역률를 개선하였다. 장기간 운항하는 선박에서의 조명등 교체 주기를 줄여 관리를 효율적으로 할 수 있도록 직병렬 배열로 LED 모듈 회로를 설계하여 LED의 일부가 손상되더라도 LED 모듈이 조명등 기능을 할 수 있도록 하였다. 개발한 구동회로를 포함한 조명기구는 전력소모와 역률이 각각 39 W, 0.925 로 선박 조명에 적합함을 확인하였다.

확률론과 위상학적 모델링을 이용한 이중 공진구조 내의 PCB 주파수 응답해석 (Frequency Response Analysis on PCB in Dual Resonant Cavity by Using Stochastical and Topological Modeling)

  • 정인환;이재욱;이영승;권종화;조춘식
    • 한국전자파학회논문지
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    • 제25권9호
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    • pp.919-929
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    • 2014
  • 최근 전자기기의 활용도가 높아짐에 따라 전자기파에 대한 안정성이 요구되었다. 소형화 전자기기 및 다양한 전자부품들은 맥스웰 방정식 (Maxwell Equation)으로 해석되었으나, 복잡도가 높은 대형 구조물에 대한 전자기파 안정성이 요구되는 현시점에 맥스웰 방정식은 여러 한계점을 가지고 있다. 본 논문에서는 복잡한 대형 구조물을 확률론과 위상학적 모델링을 연동하여 해석하고자 한다. 특히, 확률론을 바탕으로 한 해석 방법인 PWB(Power Balance) Method와 BLT(Baum-Liu-Tesch) 방정식을 연동하여 대형 구조물의 주파수 응답을 풀이할 경우, 해석시간이 상당히 줄어드는 장점이 있다. 본 논문에서는 복잡한 대형구조물의 예로 이중 공진구조 내부에 PCB가 존재하는 경우를 고려해 보았다.