• 제목/요약/키워드: Shift algorithm

검색결과 685건 처리시간 0.036초

A Neutral-Voltage-Compensated Sensorless Control of Brushless DC Motor

  • Won, Chang-Hee;Song, Joong-Ho;Ick Choy;Lim, Myo-Taeg
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • 제3B권1호
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    • pp.59-64
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    • 2003
  • This paper presents a new rotor position estimation method for brushless DC motors. The estimation error of the rotor position clearly provokes the phase shift angle misaligned between the phase current and the back-EMF waveforms, which causes torque ripple in brushless DC motor drives. Such an estimation error can be reduced with the help of the proposed neutral-voltage-based estimation method, which is structured as a closed loop observer. A neutral voltage appearing during the normal mode of the inverter operation is found to be an observable and control table measure, which can be used for estimating an exact rotor position. This neutral voltage is obtained from the DC-link current, the switching logic, and the motor speed values. The proposed algorithm, which can be easily implemented by using a single DC-link current and the motor terminal voltage sensors, is verified by simulation and experiment results.

SAW 디바이스를 이용한 냄새물질 측정 및 냄새센서 시스템의 연구 (Detection of odorants and study on the odorant sensor system by using SAW device)

  • 장상목;김기영;김종민;최용성;권영수
    • E2M - 전기 전자와 첨단 소재
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    • 제8권1호
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    • pp.48-55
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    • 1995
  • A surface acoustic wave (SAW) sensor for the detection of odorants has been constructed by depositing various phospholipids and fatty acids onto the surface of the SAW device. The characteristics of a SAW device operating at 310 MHz deposited with silicon monoxide were analyzed. Menthone, amylacetate, acetoin, and other organic gases show different affinities to the coated lipids. An explanation is given for different odorant affinities based on the monolayer properties of phospholipids. The identification of odorants depending on the tkpe of lipid used for coating is discussed in terms of the similarity of their normalized resonant frequency shift patterns. Using a number of different lipid-coated SAW devices, odorants can be identified by a computerized pattern recognition algorithm.

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새로운 선로용량을 고려한 전력계통의 상정사고 선택 (Contigency Ranking Technique Using New Line Capacity)

  • 박규홍;조양행
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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    • pp.95-98
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    • 2000
  • This paper presents a technique for contingency ranking using line capacity calculation method and outage distribution factors (LODF) which are established by generation shift distribution factors from DC load flow solutions. By using the LODF, the line flow can be calculated a ccording to the modification of base load flow if the contingency occur. To obtain contingency ranking, maximum power tansferred to the load is obtained when load impedance $Z_r$ equal to line impedance $Z_s$. The proposed algorithm has been validated in tests on a 6-bus test system.

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단일 데이터패스 구조에 기반한 AES 암호화 및 복호화 엔진의 효율적인 통합설계 (Efficient Integrated Design of AES Crypto Engine Based on Unified Data-Path Architecture)

  • 정찬복;문용호
    • 대한임베디드공학회논문지
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    • 제7권3호
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    • pp.121-127
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    • 2012
  • An integrated crypto engine for encryption and decryption of AES algorithm based on unified data-path architecture is efficiently designed and implemented in this paper. In order to unify the design of encryption and decryption, internal steps in single round is adjusted so as to operate with columns after row operation is completed and efficient method for a buffer is developed to simplify the Shift Rows operation. Also, only one S-box is used for both key expansion and crypto operation and Key-Box saving expended key is introduced provide the key required in encryption and decryption. The functional simulation based on ModelSim simulator shows that 164 clocks are required to process the data of 128bits in the proposed engine. In addition, the proposed engine is implemented with 6,801 gates by using Xilinx Synthesizer. This demonstrate that 40% gates savings is achieved in the proposed engine, compared to individual designs of encryption and decryption engine.

Adaptively tuned dynamic absorber

  • Kim, Tae-Hyun;Park, Young-Jin;Kim, Heung-Gi
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.111.4-111
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    • 2001
  • In this paper, an adaptively tuned dynamic absorber is proposed. The adaptively tuned dynamic absorber is a dynamic absorber whose stiffness is tuned so that the natural frequency of the absorber coincides with the operating or natural frequency estimated by an adaptive algorithm. The feature of this absorber is as follows. It has an electrodynamic device for the stiffness control. Using Lorenz´s force, it changes the stiffness by changing the applied current. The change of stiffness results in the natural frequency shift, because its mass and damping coefficient are fixed. We may reduce the vibration of the overall system by tuning the natural frequency of the dynamic absorber to the resonant frequency of the structure, when the dominant single tone oscilation occurs in the system ...

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적응 디지틀 전치왜곡기를 이용한 선형화된 전력증폭기의 구현 (Implementation of a Linearized Power Amplifier using a Adaptive Digital Predistorter)

  • 류봉렬;정창규;김남수;박한규
    • 전자공학회논문지A
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    • 제31A권12호
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    • pp.9-15
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    • 1994
  • In this paper, the linearized power amplifier using digital adaptive predistorter is implemented in order to restrict spectral spreading and adjacent channel interference. The linearized systems is composed of a DSP56001 processor that executes predistortion in baseband. 90.deg. phase shifter, power splitter/combiner, quadrature modulator/demodulator of 360MHz band, and nonlinear amplifier. A ${\pi}$/4-shift QPSK is used to modulate digital random signals. As the quantized power of baseband signal and the output of amplifier are fed to the predistorter, and predistorting values are calculated using an adaptive algorithm. In the experiment, a peak to sidelobe ratio of the linearized amplifier is improved up to 15dB in comparison with conventional nonlinear amplifier, which means that the distortion of transmitted signal is decreased and adjacent channel interference was reduced.

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광섬유 EFPI 센서를 이용한 실시간 고정밀 변위 측정 (Real-time Measurement of Precision Displacement using Fiber Optic EFPI Sensor)

  • 박상욱;김대현;김천곤;홍창선
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2003년도 추계학술발표대회 논문집
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    • pp.154-157
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    • 2003
  • Precision displacement of less than a few nm resolution was measured in real-time using fiber optic EFPI sensor. The novel method for real-time processing of analyzing EFPI output signal was developed and verified. Linearity in the mean values of interferometric light intensity among adjacent fringes was shown, and the sinusoidal approximation algorithm that estimates past and coming fringe values was verified through the linearity. Real-time signal processing program was developed, and the intensity signal of the EFPI sensor was transformed to the phase shift with this program. The resolution below 0.4 ~ 10 nm in the displacement range of $0 ~ 300\mu\textrm{m}$ was obtained by reducing the photodetector noise using low-pass filter and signal averaging. The nano-translation stage with a Piezo-electric actuator and the EFPI sensor system was designed and tested. This stage successfully reached to the desired destination in $15\mu\textrm{m}$ range within 1 nm accuracy.

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CAD 모델에 기초한 기상측정 (OMM (On-the-Machine Measurement) based on CAD Model)

  • 김승록;박영근;권기복;박정환;고태조;김희술;김창일
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.169-172
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    • 2000
  • In this paper, an OMM (On-the-Machine Measuring) system has been developed, which can perform measuring and inspection of sculptured surfaces of die and mold, by use of a scanning-type touch probe mounted into the spindle of a NC machine. The calibration procedures of a scanning prove (SP2-1, Renishaw) and an algorithm for measuring surface points by a ball-nosed stylus have been studied. The system has been developed based on commercial CAM software (Z-Master 2000), and tested through measuring a plastic injection molding-die. Also some experimental results of the calibration and measuring for given surface positions are analyzed to verify its accuracy and reliability.

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의료서비스로봇을 위한 얼굴추출 방법 (Face Detection for Medical Service Robot)

  • 박세현;류정탁
    • 한국산업정보학회논문지
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    • 제16권3호
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    • pp.1-10
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    • 2011
  • 본 논문에서는 의료 서비스로봇을 위한 얼굴추출 방법을 제안한다. 제안된 방법은 기존의 얼굴 추출방법의 단점을 보완하여 배경과 조명에 강건한 방법이다. 본 방법은 먼저 평균 이동 알고리즘을 이용하여 배경을 제거하고, 컬러 공간에서 얼굴을 추출한 후 외형 기반의 Haar-like feature 방식으로 최종 얼굴을 검출하게 된다. 제안된 시스템의 효율을 위해 실험을 하였고, 실험결과가 제안된 방법이 의료서비스 로봇에 적용 가능함을 보였다.

위상이동법을 이용한 3차원 형상측정법의 연구 (3-D Profilometry by Phase Shifting Profilometry)

  • 오동석;남기봉
    • 한국광학회지
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    • 제5권2호
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    • pp.191-197
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    • 1994
  • 본 연구에서는 물체의 형상을 측정하기 위하여 사용할 수 있는 여러 가지 방법중 위상이동법을 이용하여 주어진 물체의 형상을 재구성하였다. 투영하는 직선형 무늬는 Twyman-Green 간섭계를 이용하여 발생시켰고 PZT를 이용하여 이들 무늬를 공간적으로 이동시켰다. Hariharan의 위상복구 알고리즘을 사용하여 시료에 투영된 간섭무늬 영상을 해석하여 주어진 시료의 형상을 보정 상수의 범위이내로 재현할 수 있음을 보였다. 그러나 레이저광의 높은 가간섭성에 의한 여러잡음 성분들에 의한 부작용이 관찰되었으며, 정확한 보정의 문제도 주목되었다.

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