• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2090-2092
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• 2003

Adaptive algorithms are widely used for various applications. One challenging application is an echo canceller in the long distance telephony network. This paper proposes the new variable step-size algorithm for adaptive lattice structure for echo cancellation. The new algorithm is using power of the output signal and the error signal to controlled the step of adaptation process. By this technique, the proposed algorithm is an excellent and effective in good stability. Performance comparison of the proposed algorithm and the other algorithm is made through simulation results.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2E
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• pp.39-44
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• 1996

The performance of two-channel adaptive noise canceller is ofter degraded by the weights perturbation due to the speech signal. In this paper, an adaptive noise canceller employing a speech detector and two adaptation algorithms which are switched according to the speech detector is proposed. When highly correlated speech signal is detected, the tap weights of the adaptive filter are adapted by the sign algorithm. On the other hand, the weights are adapted by the NLMS algorithm when silence is detected or when the characteristics of the noise propagation channel is changed. The employed speech detector utilizes the power ratio of the input and the output of an adaptive linear prediction-error filter. According to the computer simulation, the proposed method yields better performance than conventional ones.

• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.79-87
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• 2006

This study aims to presents the applicability of apartment building for renewable energy systems using method of uncomplicated calculation and computer simulation. According to the weather conditions (NASA Surface meteorology and Solar Energy) analysis, it has been found that photovoltaic and wind power system can be applied to apartment buildings application. In case study considering layout and block plan, adaptation of solar water heating, photovoltaic and wind energy system to apartment buildings was proved to produce a profit. And the application strategies of renewable energy systems can be used not only for the investment decisions for economic analysis but also for the comparative analysis of uncomplicated calculation and computer simulation.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.841-844
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• 2001

This paper introduces a new technique for estimating the speed of a mobile station in a wireless system. The proposed method is based on the feature extraction of the received signal envelope. The undecimated discrete wavelet transform via lifting captures local minimum points of the received signal, which is used for the speed estimation. This technique requires neither knowledge of the average received power of the nonstationary signal nor adaptation of a temporal observation window, in contrast to other speed estimators given in the literature. Simulations show that the proposed speed estimator tracks the variable speed of the mobile station.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.74-76
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• 1996

This measurement method described in this paper can be applied for the accurate determination for voltage and current of inverter with harmonics. The method, based on a thermal principle, relies on adaptation of the measurement thermal e.m.f to signal of inverter and comparison of AC to DC signals. The performance of the measurement system is compared with calculated results and reference power system. With this method, an accuracy of 0.1% can be achieved.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.70-78
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• 1997

A DSP-based nonlinear speed control of a permanent magnet synchronous motor(PMSM) which is robust to unknown parameter variations and speed measurement error is presented. The model reference adaptive system(MRAS) based adaptation mechanisms for the estimation of slowly varying parameters are derived using the Lyapunov stability theory. For the disturbances or quickly varying parameters, a quasi-linearized and decoupled model including the influence of parameter variations and speed measurement error on the nonlinear speed control of the PMSM is derived. Based on this model, a boundary layer integral sliding mode controller to improve the robustness and performance of a PMSM drive is designed and compared with the conventional controller. To show the validity of the proposed control scheme, simulations and experimental works are carried out and compared with the conventional control scheme.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.34-39
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• 1997

With the development of semiconductor devices, adaptation of microcontroller prevails in industrial area. But in arc welding industry, there has not been much progress in adoption of microcontroller technology. There fore, this paper shows the application of digital control technology to welding machine. This paper presents the design of microcontroller that is appropriate for three phase $CO^2$ gas metal ar welding machine. By using microcontroller in $CO^2$ gas metal arc welding machine, the overall cost can be reduced compared to analog type one. Also TMS370C850 microprocessor is used as overall micrecontroller for the arc welding machine.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.89-96
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• 1997

A robust speed control scheme for a brushless DC(BLDC) motor using an adaptive input-output linearization technique is presented. By using this technique, the nonlinear motor model can be linearized in Brunovski canonical form, and the desired speed dynamics can be obtained based on the linearized model. This control technique, however, gives an undesirable output performance under the mismatch of the system parameters and load conditions. For the robust output response, the controller parameters will be estimated by a model reference adaptive technique where the disturbance torque and flux linkage are estimated. The adaptation laws are derived by the Popov's hyperstability theory and positivity concept. The proposed control scheme is implemented on a BLDC motor using the software of DSP TMS320C30 and the effectiveness is verified through the comparative experiments.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.2
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• pp.375-382
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• 2001

In this study, an adapted Turbo Coding Algorithm for reducing communication error of a fire detection system for marine vessels, especially image transmission via power lone. Because it is necessary that this system communicate larger and faster than previous method, this study carried out enhancement a decoding speed by adaptation CRC with Turbo Code Algorithm, improvement of metric method, and reduction of decoding delay by using of Center-to-Top method. And the results are as follows: (1) Confirmed that a Turbo Code is so useful methods for reducing communication error in lots of noise environments. (2)Proposed technology in this study speed increasing method of Turbo Coding Algorithm proves 2 times faster than normal Turbo Code and communication error reducing as well in the board made by VHDL software & chips ALTERA company.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.96-100
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• 2015

Adaptive background gain calibration loop for multi-lane serial links is proposed. In order to detect and cancel gain mismatches between lanes, a single digital loop using a ${\sum}{\Delta}$ ADC is employed, which provides a real-time adaptation of gain variations and is shared among all lanes to reduce power and area. Evaluation result showed that gain mismatches between lanes were well calibrated and tracked, resulting in timing budget at $10^{-6}$ BER increased from 0.261 UI to 0.363 UI with stable loop convergence.