• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.115-120
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• 2004

Most of the LV customer have been applied the distribution system of 3-phase four wire system because of its advantage of supplying both of 1-phase & 3-phase loads simultaneously. Due to its structural simplicity, it is more convenient for use rather than the conventional separated scheme. But uneven load distribution or unclean voltage quality has occurred various problems such as do-rating, losses increase and vibration, etc. In this paper, voltage, current and power waveform in the actual fields have measured and analyzed in relation with internationally allowable voltage unbalance limits and compared the current unbalance factor with the load unbalance factor.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.166-172
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• 1996

This paper presents the characteristics of the crankshaft speed fluctuations. To analyze them, the speed waveforms were measured both at the flywheel and at the front end of the engine. The speed waveform measured at the flywheel shows better result than at the front end one, because of the torsional vibration and the auxiliary components. And the patterns of the speed fluctuations are classified into three region, such as low load, middle load and high load region with the variations of the loads. Additionally, as the engine speeds increase and the loads decrease, the analysis of the speed becomes more difficult due to lower variation of the speed. And in all the regions, the main frequency component of the speed fluctuation is firing frequency.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.156-160
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• 1997

In this paper, the control scheme is proposed that PI controller parameter used for TAH speed control is adapted by fuzzy logic method using only the motor current waveform. By scheduling PI parameters, minimization of the vibration and the energy consumption and overcoming AoP loads becomes possible. In in vitro tests experimental results show our approach is a good scheme that is adapted to changing afterloads well.

• 전력전자학회논문지
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• 제3권3호
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• pp.199-205
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• 1998

브러시리스 직류 전동기는 역기전압이 사다리꼴로서 구형파 상전류를 순차적으로 인가해야 한다. 센서리스 드라이브와 같이 전류 제어 기능 없이 전압원 인버터로 브러시리스 직류 전동기를 구동하는 경우 상전류가 전환되면서 토크 리플이 발생한다. 본 논문에서는 전환에 의한 토크 리플에 관하여 분석하고, 이의 저감 대책을 제안하며, 센서리스 드라이브에 적용하여 토크 리플에 의한 진동과 소음을 개선함으로서 그 효과를 입증한다.

• 한국정밀공학회지
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• 제13권2호
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• pp.168-175
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• 1996

The measured vibration on a machine or a structure is shaped by the excitation waveform and the path transfer function. Mechanism diagnostics tends to focus on retrieving source features by minimizing the effects of the structiral path, while in structural diagnostics we are more interested in minimizing source effects and retrieving path parameters. In structural diagnostics, therefore, there are experimental issues of gathering date that are independent source effects and finding a transfer function signature that reveals structural defects. This paper describes how the transfer function can be obtained more accurately by experiment using the compatibility relationship which is newly discovered.

• International Journal of Internet, Broadcasting and Communication
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• 제8권4호
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• pp.48-53
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• 2016

Noise and vibration pollution is emerging to people in high speed trains. And it is difficult to realization of eco-friendly railway system at noise problem. The railway internal noise is 73dB on average and over 80dB in the loudest section. In order to reduce noise, there are passive methods that are far from noise sources and theother active noise reducion method. In this paper, we propose a method of reduce noise by measure and estimate the noise condition of train environment using Bone-Conduction device. We use an anti-phase waveform for canceling of noise characteristic. With this new system, the noise from surrounding environments can be reduced.

• 대한의용생체공학회:의공학회지
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• 제7권1호
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• pp.3-10
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• 1986

In this paper, a scanconverter which displays the biological signals of low frequency on CRT for the purpose of easy read-out is attempted to design for using the CRTC, and it stows some good effectivenesses The results obtained in this experiment are as follows : (1) Using only one chip, CRT controller, it can display both waveforms and characters simultaneously. (2) The flexibility of CPU program can be obtained using the sub-microproce ssor function of CRTC chip. (3) The trend of digital data is possible through the graphic function (4) The vibration of displayed waveform can be prevented using the chip simplification and the trigger signal of one chip. (5) Operation with microprocessor malies the expansion and interface easy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.815-816
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• 2006

This paper proposes a novel design method for flux barrier which built in q-axis in rotor of IPM type BLDC motor. It aims to reduce the motor vibration with reduced cogging torque and lessened torque ripple by the sinusoidal waveform distribution of flux generated in the permanent magnet, which results from designed flux barriers. Design of flux barrier optimized using the Taguchi methods that considered multiple quality characteristics, such as cogging torque, average torque and efficiency are considered. The result of proposed method is compared and verified with 2D finite element method (FEM).

• 전기학회논문지P
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• 제54권2호
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• pp.88-93
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• 2005

Most of the LV customer have been applied the distribution system of 3-phase four wire system because of its advantage of supplying both of 1-phase & 3-phase loads simultaneously. Due to its structural simplicity, it is more convenient for use rather than the conventional separated scheme. But uneven load distribution or unclean voltage quality has occurred various problems such as de-rating, losses increase and vibration, etc. In this paper, voltage, current and power waveform in the actual fields have measured and analyzed in relation with internationally allowable voltage unbalance limits and compared the current unbalance factor with the load unbalance factor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.108-110
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• 1999

In this paper, approximate means of estimating the flux and torque levels in an induction motor is discussed. There exists several method that is used directly by flux meter and flux sensing coils in the airgap. Most of these methods are sensitive to motor parameter value changes. Also, the harmonics in the motor voltage and current due to the nonsinusodial inverter waveform cause errors in the estimated torque. Finally, this result is applicated in arch type linear induction motor for study of noise and vibration.