• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.6
• /
• pp.147-153
• /
• 2003

In this paper, implementation of active noise barriers(ANB) to attenuate exterior noise which is propagated through open windows is presented. The leaky multiple channel LMS algorithms are used for adaptive filters tc improve the convergence property, and a new type of the active noise barrier is proposed. The attenuation effects of conventional active noise control(ANC) systems using leaky multiple channel LMS algorithms and the proposed system are compared by experiments using a TMS320C33 digital signal processor. Noise attenuation levels at the points of error microphones are similar for both systems, but average noise attenuation effects of the proposed system for an entire space of an experimental enclosure are much better than conventional ANC systems.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2016.06a
• /
• pp.237-239
• /
• 2016

본 논문에서는 HEVC (High Efficiency Video Coding) 복호화기의 SAO (Sample Adaptive Offset)를 효율적으로 병렬화하기 위한 방법을 제안한다. HEVC 는 주관적 화질 향상 및 압축 효율 향상을 위해 디블록킹 필터 (de-blocking filter)와 샘플 적응적 오프셋 (SAO)이라는 두 가지 인-루프 필터를 사용한다. 두 종류의 인-루프 필터의 사용은 HEVC 복호화기의 복잡도를 증가시키는 요인이며, 인-루프 필터에 데이터레벨 병렬화를 적용하여 고속으로 복호화를 수행할 수 있다. 본 논문에서는 SAO 의 병렬화를 위해 CTU (Coding Tree Unit)의 행 단위로 병렬화를 수행함으로써, 병렬화로 인한 추가적으로 발생하는 라인 버퍼 사용을 줄여 SAO 병렬화 효율을 향상시켰다. 실험결과 제안하는 SAO 병렬화 방법을 사용하여 균등분할 SAO 병렬화 방법에 비해 91%의 속도를 향상시켰다.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.4
• /
• pp.369-375
• /
• 2011

Design is important in the IT, digital appliance, and auto industries. Aesthetic and art images are being applied for better quality of the products. Most image patterns are complex and much lead-time is required to implement them to the product design process. A precise reverse engineering method generating 2.5D engraving models from 2D artistic images is proposed through the image processing, NURBS interpolation and 2.5D reconstruction methods. To generate 2.5D TechArt models from the art images, boundary points of the images are extracted by using the adaptive median filter and the novel MBF (modified boundary follower) algorithm. Accurate NURBS interpolation of the points generates TechArt CAD models. Performance of the developed system has been confirmed through the quick turnaround 2.5D engraving simulation linked with the commercial CAD/CAM system.

• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2671-2673
• /
• 2004

Noise can make surrounding environments inferior and deteriorates operation efficiency, and it can bring aural damage as well as give a person psychological stress. Therefore, necessity of study about noise control is increased for better labor conditions and agreeable habitat. In this paper, implementation of active mufflers using active noise control techniques is presented. The LMS algorithm is used for adaptive filter algorithms. Computer simulations and experiments using TMS320C32 digital signal processor have performed to show the effectiveness of a proposed algorithm.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.10
• /
• pp.141-150
• /
• 1997

In this paepr, we propose an intelligent double talk detector that can enhance the performance of the acoustic echo cancellation system. The conventional double talk detection methods often misunderstand the echo path changes as double talk. Although there exist several detection methods that can distinguish the echo path changes from the double-talks, they show poor tracking performance because of the excessive decision delay for the discrimination and can only be used after the adaptive digital filter converges. A new and more effective ditetion algorithm has been proposed, where the detection mechanism is performed by observing the change rate of the reflection coefficients of the two lattice predictors that re placed on the near-end and far-end terminals. The excellence of the proposed method is verified by extensive computer simulations using real speech signals.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.10a
• /
• pp.164-169
• /
• 1998

This paper deals with condition monitoring for tool wear during tuning operation. To develop economic sensing and identification methods for turning processes, sound pressure measurement and digital signal processing technique are proposed. To identify noise sources of tool wear and reject background noise, noise rejection methodology is proposed. features to represent condition of tool wear are obtained through analysis using adaptive filter and FFT in time and frequency domain. By using fuzzy pattern recognition, we extract features, which are sensitive to condition of tool wear, from several features and make a decision on tool wear. The validity of the proposed system is condirmed through the large number of cutting tests in two cutting conditions.

• Journal of KSNVE
• /
• v.6 no.6
• /
• pp.851-856
• /
• 1996

The active noise cancellation system showing the effective convergence and stability has been studied by simplifying the controller structures using the weighting factors of control error path to the multi-channel filtered-x LMS algorithm which needs a lot of calculations and the performance has been verified experimentally. Besides, to implement the system performance in a vehicle cabin, experimental work for selecting the suitable numbers and positions of the microphones and speakers was accomplished. Effectively combining a TMS 320C 31 main processor conducting real number calculations and having various functions with other components, the purpose-built system board for active noise cancellation has been designed and with this board, car active noise cancellation system showing maximum stable 10dB noise reduction has been obtained at the car idling conditions above 3000rpm range.

• The Journal of the Acoustical Society of Korea
• /
• v.12 no.6
• /
• pp.13-20
• /
• 1993

충격 응답 시간이 긴 시스템을 모델링하기 위한 실시간 적응 디지털 필터를 구현하였다. 대상 시스템의 충격 응답 시간이 길 때, 일반적인 적응 디지털 필터를 사용하는 경우 발생하는 수렴 속도 저하와 계산량 증가 문제를 해결하기 위해서 서브밴드 구조를 갖는 적응 디지털 필터를 구성하였다. 실시간 처리 시스템에서는 GQMF을 사용하여 입력 신호를 4개 대역으로 분할하여 각 대역별로 적응 필터링을 수행함으로써 수렴 속도를 향상시킨다. 또한 대역별 신호를 동시에 분산 처리하기 때문에 계산량 면에서 효율적이므로 시스템의 충격 응답이 긴 경우에는 실시간 처리가 가능하다. 하드웨어 구성은 범용 신호 처리 프로세서인 DSP56001을 호스트 프로세서로 사용하며, 적응 디지털 필터 칩 DSP56200을 사용하여 각 대역 적응 필터를 구성하였다. 실험은 충격 응답 시간이 16 kHz 필터링 시 2000 탭 길이로 가정된 시스템을 대상으로 부동 소수점 시뮬레이션 결과와 실시간 처리 시스템의 결과를 비교하였다. 밴드를 나누지 않은 기존의 방법과 서브밴드 시스템의 비교 실험 결과 입력이 백색 잡음인 경우 대역별 간섭에 의한 성능 저하가 있었으나, 음성과 유사한 특성을 갖는 유색 잡음인 경우 서브밴드 시스템이 단일 시스템에 비해 성능 향상을 보였다.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.9
• /
• pp.23-30
• /
• 1997

In this paper, a decision feedback recurrent neural equalization (DFRNE) scheme is proposed for adaptive equalization problems. The proposed equalizer models a nonlinear infinite impulse response (IIR) filter. The modified Real-Time recurrent Learning Algorithm (RTRL) is used to train the DFRNE. The DFRNE is applied to both linear channels with only intersymbol interference and nonlinear channels for digital video cassette recording (DVCR) system. And the performance of the DFRNE is compared to those of the conventional equalizaion schemes, such as a linear equalizer, a decision feedback equalizer, and neural equalizers based on multi-layer perceptron (MLP), in view of both bit error rate performance and mean squared error (MSE) convergence. It is shown that the DFRNE with a reasonable size not only gives improvement of compensating for the channel introduced distortions, but also makes the MSE converge fast and stable.

• Journal of Information Display
• /
• v.3 no.2
• /
• pp.19-25
• /
• 2002

In this paper, a new target extraction algorithm is proposed, in which the coordinates of target are obtained adaptively by using the difference image information and the optical BPEJTC(binary phase extraction joint transform correlator) with which the target object can be segmented from the input image and background noises are removed in the stereo vision system. First, the proposed algorithm extracts the target object by removing the background noises through the difference image information of the sequential left images and then controlls the pan/tilt and convergence angle of the stereo camera by using the coordinates of the target position obtained from the optical BPEJTC between the extracted target image and the input image. From some experimental results, it is found that the proposed algorithm can extract the target object from the input image with background noises and then, effectively track the target object in real time. Finally, a possibility of implementation of the adaptive stereo object tracking system by using the proposed algorithm is also suggested.