• The Journal of the Acoustical Society of Korea
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• v.16 no.5
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• pp.18-25
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• 1997

The feedforward control algorithm for active noise control exhibits high stability and performance robustness. But it has a slow convergence speed and requires a correlated reference signal. Broadband active control systems typically use feedback control in order to increase the convergence speed and to avoid the problems associated with obtaining and decoupling a suitable reference signal. However, it is well known that conventional feedback control systems have a gain-bandwidth limitation and stability problem. This paper presents the new system based on the combination of both feedforward and feedback system in order to increase the convergence speed. The proposed system uses a proposed control algorithm termed "optional-summed" algorithm in which the "optional summed reference signal" comprised of weighted sum of an original reference signal and a eror signal, is used as an input to an adaptive system. Thus, the proposed system can have faster convergence speed and better performance than either feedforward or feedback system using the Filtered-x LMS algorithm as almost equivalent complexity of computation as it. Several simulation results demonstrating the good properties of the proposed adaptive system as well as verifying the analytical results are also presented in the paper.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.376-380
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• 2004

This paper is to develop an optical ruer displacement sensor for monitoring high speed spindle. Proper magnitude of optical power as well as amplification of output signal are necessary to improve sensitivity of the sensor. In this paper, to meet the need of improvement of the sensor resolution, we choose proper optical power and amplification level through speculating on optical power of a laser diode.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.975-978
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• 1999

The transmission line effects of IC interconnects have a substantial effect on a hish-speed VLSI circuit performance. The effective transmission lime parameters are changed with the increase of the operation frequency because of the skin of the skin effect, proximity effect, and silicon substrate. A new signal delay estimation methodology based on the RLC-distributed circuit model is presented ［2］. The methodology is demonstrated by using SPICE simulation and a high-frequency experiment technique.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.155-160
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• 2002

In this paper, a controller design for brushless linear motor is implemented. The designed controller is mainly composed of current, speed and position controller, which are carried out by the high-speed digital signal processor (DSP). In addition the PWM inverter is controlled by space voltage PWM method. This system is implemented by using 32-bit DSP (TMS320C31), a high-integrated logic device (EPM7192), and IPM (Intelligent Power Module) for compact and powerful system design. The experimental results show the effective performance of controller for the brushless linear motor.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.152-156
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• 2009

This paper examines the BER performance of the recently proposed half-symbol-rate-carrier (HSRC) offset quadrature phase-shift-keying (OQPSK) receiver for high-speed data communication. A modified demodulation technique using a bit-time period signal integration, the bit-error-rate (BER) performance of the HSRC-OQPSK signal improves more than 4dB compared to that of a demodulation technique using a symbol-time period integration. This paper also examines the BER performance of modified demodulation with various band-limited channels modeled using low-pass filters, and the three different data-rate systems are simulated and compared with the performance of the system using the conventional demodulation technique.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.174-176
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• 2000

In this paper, a high speed distance relay, using a digital signal processor(DSP) is presented. The idea of the protective algorithm is based on the least square method using minimum data window to minimize the relay operating time. A new disign concept for a low-pass filter is proposed. This analog low pass filter has minimum transient response time. The main processor of the relay is TMS320C31. According to a series of real time tests, the proposed protective relay shows reliable and fast operating characteristics.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.372-376
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• 2004

Digital memory circuits have been developed very fast according to the progress of semiconductor technology But It was very difficult to memorize a high frequency radio signal. Many years ago an analog loop was used for store of radio frequency signal, and the digital radio frequency memory was made to the development of wideband amplifier and high speed sampler. We present a design of wide-band DRFM using Johnson code and the simulation results with respect to the sampling speed. in this paper.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.521-524
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• 1990

There is an increasing interest in high-speed signal processing in modern telecommunication and consumer electronics applications. HDTV, ISDN. A limiting factor in Op-Amp based analog integrated circuits is the limited useful frequency range. This research program will develop a new CMOS Op-Amp architecture with improved gainband width product. The new design CMOS Op-Amp will achieve up to 100MHz unity gainband width with a 1.5-micron design rule.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.6
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• pp.266-271
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• 2001

In this paper, a controller design for coreless linear synchronous motor is proposed. The designed controller is mainly composed of speed and current control, which are carried out by the high-speed digital signal processor(DSP). In addition the PWM inverter is controlled by space voltage PWM method. This system is implemented using by 32-bit DSP(TMS320C31), a high-integrated logic device(EPM940), and IPM(Intelligent Power Modules) for compact and powerful system design. The experimental results show the effective performance of controller for coreless linear synchronous motor.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.326-328
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• 2005

High speed rotational arc sensing is an important method to detect the torch deviation during automatic seam tracking of arc welding. In this paper, a mathematic model of high speed rotational arc sensing is analyzed. The simulation results are consistent with the experimental results. The current waveforms at the beginning of the welding are different from those at middle of the welding because of the formation of the weld bead profile. The signal patterns for seam tracking and end-point detection are proposed. A phase shift between the rotation and the current variation is also discovered in the experiments.