• The Journal of the Acoustical Society of Korea
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• v.22 no.2
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• pp.96-103
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• 2003

This paper describes a method for sinusoidal modeling of audio signals using perceptually weighted matching pursuit. Matching pursuits extracts iteratively the greatest energy signals from the input signals until the residual between the original and the reconstructed signal is zero. In this paper, perceptual matching pursuits using psychoacoustic model to matching pursuit extracts greatest perceived energy iteratively. To evaluate the performance of the perceptual matching pursuits it is compared with the sinusoidal matching pursuits which is not included perceptual weighting. For various audio signals the result of simulation shows that the perceptual matching pursuit is superior to the sinusoidal matching pursuits, especially for a high change rate in time domain it can synthesized original signal.

• The Journal of the Acoustical Society of Korea
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• v.19 no.4
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• pp.58-68
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• 2000

This paper proposes a sinusoidal modeling of polyphonic audio signals. Sinusoidal modeling which has been applied well to speech and monophonic signals cannot be applied directly to polyphonic signals because a window size for sinusoidal analysis cannot be determined over the entire signal. In addition, for high quality synthesized signal transient parts like attacks should be preserved which determines timbre of musical instrument. In this paper, a multiresolution filter bank is designed which splits the input signal into six octave-spaced subbands without aliasing and sinusoidal modeling is applied to each subband signal. To alleviate smearing of transients in sinusoidal modeling a dynamic segmentation method is applied to subbands which determines the analysis-synthesis frame size adaptively to fit time-frequency characteristics of the subband signal. The improved dynamic segmentation is proposed which shows better performance about transients and reduced computation. For various polyphonic audio signals the result of simulation shows the suggested sinusoidal modeling can model polyphonic audio signals without loss of perceptual quality.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.9-13
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• 1997

In this paper, the operation regions of a three-phase voltage-source PWM converter are defined: linear modulation region, allowed current region, linear control region, unity power-factor region, and power-factor decreasing region. Particularly, the power-factor decreasing region is first examined and defined as the region where both the sinusoidal input current control and the stable DC link voltage regulation can not be obtained with a unity power-factor operation. To avoid these undesirable effects, the optimal current vector is derived, which ensures the sinusoidal input current and the stable DC link voltage regulation with maximum power-factor available, and, in consequence, it extends the operation region of the PWM converter. The validity of the proposed control scheme is proved by the computer simulation.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1206-1210
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• 1992

To satisfy the requirements of a stable speed control, comfortable ride and precise landing in the high-speed elevator. The induction motor driving elevator is controlled by inverter using vector control method which calculates optimum torque to apply to the Induction motor. This paper describes the control system of high-speed elevator that consists of the voltage-type PWM converter with an unity input power factor and sinusoidal input current and the voltage-type PWM inverter with a precise speed control and sinusoidal output current. The test results of actual elevator are presented.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.91-98
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• 1995

To control speed or torque of induction motors, scalar control method that regulates the value of stator current had been used conventionally. But, vector control method which contrls the direction and the value of stator current at the same time has been introduced lately and employed widely. This paper describes comparative analyses of above two methods by computer simulation. As a result of the simulation, both methods showed good responses for high speed, but, vector control method characterized much better performance for low speed and sinusoidal input.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.290-293
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• 2002

For small capacity rectifier circuits such as these for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor connection scheme using a LC resonant in commercial frequency without switching devices. In this method, It makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence, the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh orders are much reduced. The result are confirmed by the theoretical and experimental implementations.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2121-2123
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• 1998

In recent years, A PWM Converter or Switched Mode Converter with high power factor and sinusoidal input current have got widespread studied. But, Almost all of studies is based on linear load. This paper reports on research aimed at achieving high power factor and sinusoidal input current waveform for electronic arc welder, which has nonlinear dynamic characteristics. It is shown that simulation result yield its property.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.58-60
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• 1998

The precise measurement of consumed power during the given time is very important in the energy management aspect. Up to days, induction watthour meter has been designed for use in the alternating circuits in which the voltage and current are essentially sinusoidal. The use of switching elements in power system causes the current or voltage involving harmonics. Therefore the registration error is caused by harmonics in the equipment for measuring power. This paper presents the registration error of the induction watthour meter in the presence of harmonic distortion. The accuracy of a watthour meter on loads in which the input source is not sinusoidal is investigated. And the effects of individual harmonic are reported by experiment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.751-754
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• 2015

This paper deals with a robust speed control problem of a vertical one-link manipulator in the presence of parameter uncertainties and unknown input disturbance. Uncertain load weight causes an additional sinusoidal disturbance in the rotation of the link. In order to improve the robustness against parameter uncertainties and external input disturbances, this paper employs an internal model-based disturbance observer approach. Comparative computer simulations are performed to test the performance of the proposed controller. The simulation results show the enhanced performance of the proposed method.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.178-179
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• 2017

Input filter is an essential component in a practical matrix converter (MC) system to generate the sinusoidal input currents. However, the input filter causes a displacement angle between the input current of MC and the source current. In this paper, we investigate the input filter design for MCs by considering the displacement angles of the input current and the input voltage to guarantee high input power factor (IPF) operation as well as low input current harmonic contents. Simulation results are provided to validate the input filter design with near unity input power factor and low total harmonic distortion (THD) of the input current.