• MALSORI
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• no.50
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• pp.85-97
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• 2004

One of the important problems in speech recognition is to accurately detect the existence of speech in adverse environments. The speech detection problem becomes severer when recognition systems are used over the telephone network, especially in a wireless network and a noisy environment. In this paper, we propose a robust speech detection algorithm, which detects speech boundaries accurately by selecting useful bands adaptively to noisy environments. The bands where noises are mainly distributed, so called, noise-centric bands are introduced. In this paper, we compare two different speech detection algorithms with the proposed algorithm, and evaluate them on noisy environments. The experimental results show the excellence of the proposed speech detection algorithm.

• ETRI Journal
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• v.29 no.3
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• pp.300-304
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• 2007

This paper proposes a new data-driven method for high-pass approaches, which suppresses slow-varying noise components. Conventional high-pass approaches are based on the idea of decorrelating the feature vector sequence, and are trying for adaptability to various conditions. The proposed method is based on temporal local decorrelation using the information-maximization theory for each utterance. This is performed on an utterance-by-utterance basis, which provides an adaptive channel normalization filter for each condition. The performance of the proposed method is evaluated by isolated-word recognition experiments with channel distortion. Experimental results show that the proposed method yields outstanding improvement for channel-distorted speech recognition.

• The Journal of the Acoustical Society of Korea
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• v.14 no.4
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• pp.96-99
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• 1995

Under signal range mismatch, the LCMV beamformer has the performance degradation to cancel a desired signal. Using the eigenstructure properties of the array covariance matrix, we investigate the cause of this problem. From this investigation, a robust beamformer to source range mismatch is presented. The proposed beamformer has the maximum output signal-to-noise ration (SNR). When a desired signal is in a far field, the weight vector of the proposed beamformer is not biased.

• Proceedings of the KIEE Conference
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• 2006.10b
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• pp.181-184
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• 2006

In this study, an robust adaptive backstepping controller is proposed for the speed control of separately excited DC motor with uncertainties and disturbances. Armature and field resistance, damping coefficient and load torque are considered as uncertainties and noise generated at applying load torque to motor is also considered. It shows that the backstepping algorithm can be used to solve the problems of nonlinear system very well and robust controller can be designed without the variation of adaptive law. Simulation and experiment results are provided to demonstrate the effectiveness of the proposed controller in the future.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.657-660
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• 2001

In this paper, a robust watermarking technique is presented by using a block-based statistics in DCT domain. First, the proposed technique calculates JND threshold value using the global statistics in DCT domain. Then watermark insertion is carried out by inserting one watermark into coefficients which are above the threshold value J within a 2${\times}$2 block. Finally, watermark is estimated by averaging the extracted watermarks from the coefficients which are above the threshold in a window. In experiments it is shown that the proposed techniques can enhance perceptual invisibility and robustness against additive noise and JPEG compression attacks by using the characteristics of JND.

• Journal of Broadcast Engineering
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• v.7 no.2
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• pp.192-201
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• 2002

This paper develops a novel robust information hiding technique that uses channel codes derived from the error-correcting coder. The message encoded by the cover encoder is hidden in DCT transform domain of the cover image. The method exploits the sensitivity of human eyes to adaptively embed a visually recognizable message in an image without affecting the perceptual quality of the underlying cover image. Experimental results show that the proposed data hiding technique is robust to cropping operations, lossy JPEG compression, noise interference and secure against known stego attacks. The performance of the proposed scheme with turbo coder is superior to that without turbo coder.

• Korean Journal of Computational Design and Engineering
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• v.9 no.4
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• pp.351-360
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• 2004

An optimal robust design methodology has been developed to minimize the warpage in a decorating panel of monitor molded by the plastic injection. For the associated methodology, the Taguchi's Design Of Experiment (DOE) based on orthogonal arrays and Signal-to-Noise Ratio is combined with commercial simulation tools f3r injection molding. An optimal robust design solution is statistically resulted from the computational simulation. The related experiment was done for evaluations of the warpage in the decorating panel part of monitor. This research showed that the warpage under the applied optimal design conditions was comparatively reduced.

• Speech Sciences
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• v.15 no.1
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• pp.75-83
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• 2008

The interior of an automobile is a very noisy environment with both stationary cruising noise and the reverberated music or speech coming out from the audio system. For robust speech recognition in a car environment, it is necessary to extract a driver's voice command well by removing those background noises. Since we can handle the music and speech signals from an audio system in a car, the reverberated music and speech sounds can be removed using an acoustic echo canceller. In this paper, we implement an acoustic echo canceller with robust double-talk detection algorithm using TMS-320C6711 DSK. First we developed the echo canceller on the PC for verifying the performance of echo cancellation, then implemented it on the TMS320C6711 DSK. For processing of one speech sample with 8kHz sampling rate and 256 filter taps of the echo canceller, the implemented system used only 0.035ms and achieved the ERLE of 20.73dB.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.127-134
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• 2010

Additive noise and channel mismatch strongly degrade the performance of speaker verification systems, as they distort the features of speech. In this paper a histogram transformation technique is presented to improve the robustness of text-independent speaker verification systems. The technique transforms the features extracted from speech such that their histogram is conformed to a reference distribution. The effect of different standard deviations for the reference distribution is investigated. Experimental results indicate that, in channel mismatched environments, the proposed technique offers significant improvements over existing techniques. We also verify performance improvement of the proposed method using statistics.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.628-631
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• 2000

A new control method for precision robust speed control of a PMSM(Permanent Magnet Synchronous Motor) using load torque observer is presented. With this system we can obtain more reliable eye moving singal(nystagmus) Until now rotating chair system which is called 2D-optokinetic stimulator is used to make dizzincess. However an inclined rotating chair system witch is 3D-optokinetic stimulator is needed to obtain the precise dizziness data. This 3D-optokinetic sitimulator include unbalanced load aused by unbalanced center of mass. For this case new compensation method is considered to obtain robust speed control using load torque observer. To reduce the effect of this disturbance we can use dead-beat observer which has high gain. The application of the load torque observer is published in [1] for position control. A problem of using speed information such as amplifying effect of noise is reduce by moving average process. The experimental results are depicted in this paper to show the effect of this proposed algorithm.