• Title/Summary/Keyword: adaptive signal processing

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Design of u-Healthcare RF-Tag Based on Heart Sounds of Chest (흉부 심음을 기반한 u-헬스케어용 RF-Tag설계)

  • Lee, Ju-Won;Lee, Byeong-Ro
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.4
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    • pp.753-758
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    • 2009
  • This paper is proposed the hardware structure and signal processing method of the RF-Tag based on heart sound to develop the mobile biomedical information device for the u-healthcare system. The RF-Tag in this study is consisted of a skin temperature sensor, a dynamic microphone for heart sound detection, Bluetooth communication to transmute healthcare data, and pulse period detection algorithm with adaptive gain controller. We experimented to evaluate performance of the RF-Tag in noisy environments. In addition, the RF-Tag has shown the good performance in the results of experiment. If the proposed methods in this study apply to design the u-healthcare device, we will be able to get the exact health data on real time in mobile environments.

A Study on Cascade Filter Algorithm for Random Valued Impulse Noise Elimination (랜덤 임펄스 잡음제거를 위한 캐스케이드 필터 알고리즘에 관한 연구)

  • Yinyu, Gao;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.3
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    • pp.598-604
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    • 2012
  • Image signal is corrupted by various noises in image processing, many studies are being accomplished to restore those images. In this paper, we proposed a cascade filter algorithm for removing random valued impulse noise. The algorithm consists two steps that noise detection and noise elimination. Variance of filtering mask and center pixel variance are calculated for noise detection, and the noise pixel is replaced by estimated value which first apply switching self adaptive weighted median filter and finally processed by modified weight filter. Considering the proposed algorithm only remove noise and preserve the uncorrupted information that the algorithm can not only remove noise well but also preserve edge.

A Watermarking System using Adaptive Thresholds (적응 임계값을 사용한 워터마킹 시스템)

  • Sang-Heun Oh;Sung-Wook Park;Bvyung-Jun Kim
    • Journal of KIISE:Information Networking
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    • v.30 no.1
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    • pp.30-37
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    • 2003
  • In this paper, a discrete wavelet transform (DWT)-based watermarking system is proposed. The main feature of proposed system is that the embedding system uses adaptive thresholds to control the trade-off between the qualify of the watermarked image and the capacity of the watermark, and the trade-off between the quality and robustness of the watermarked image. Also, the extracting system rebuilds threshold according to various attacks and decides a watermark bit from the least distorted coefficient after measuring the distortion of coefficient. Finally, a new measure to detect the uniqueness of watermark is proposed. The experimental result shows that the proposed watermarking system is robust against conventional signal processing and intentional attacks.

A Study on Extracting Valid Speech Sounds by the Discrete Wavelet Transform (이산 웨이브렛 변환을 이용한 유효 음성 추출에 관한 연구)

  • Kim, Jin-Ok;Hwang, Dae-Jun;Baek, Han-Uk;Jeong, Jin-Hyeon
    • The KIPS Transactions:PartB
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    • v.9B no.2
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    • pp.231-236
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    • 2002
  • The classification of the speech-sound block comes from the multi-resolution analysis property of the discrete wavelet transform, which is used to reduce the computational time for the pre-processing of speech recognition. The merging algorithm is proposed to extract vapid speech-sounds in terms of position and frequency range. It performs unvoiced/voiced classification and denoising. Since the merging algorithm can decide the processing parameters relating to voices only and is independent of system noises, it is useful for extracting valid speech-sounds. The merging algorithm has an adaptive feature for arbitrary system noises and an excellent denoising signal-to-noise ratio and a useful system tuning for the system implementation.

Implementation of Finger-Gesture Game Controller using CAMShift and Double Circle Tracing Method (CAMShift와 이중 원형 추적법을 이용한 손 동작 게임 컨트롤러 구현)

  • Lee, Woo-Beom
    • Journal of the Institute of Convergence Signal Processing
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    • v.15 no.2
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    • pp.42-47
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    • 2014
  • A finger-gesture game controller using the single camera is implemented in this paper, which is based on the recognition of the number of fingers and the index finger moving direction. Proposed method uses the CAMShift algorithm to trace the end-point of index finger effectively. The number of finger is recognized by using a double circle tracing method. Then, HSI color mode transformation is performed for the CAMShift algorithm, and YCbCr color model is used in the double circle tracing method. Also, all processing tasks are implemented by using the Intel OpenCV library and C++ language. In order to evaluate the performance of the proposed method, we developed a shooting game simulator and validated the proposed method. The proposed method showed the average recognition ratio of more than 90% for each of the game command-mode.

Vehicle Plate Extraction Algorithm for an Exculsive Bus Lane (버스 전용차선에서의 차량 번호판 추출 알고리즘)

  • 설성욱;이상찬;주재흠;강현인;남기곤
    • Journal of the Institute of Convergence Signal Processing
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    • v.2 no.4
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    • pp.31-37
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    • 2001
  • License plate recognition system for an exclusive bus-lane is made of 5 core parts which are vehicle detection, image acquisition individual character extraction, character recognition and data transmission. Among them, the accuracy of license plate extraction can bring effect significantly to the accuracy of a whole system recognition rate also the more exact extraction of license plate is required in various weather and environment conditions. Therefore in this paper we propose a plat extraction algorithm that makes pyramid structure to reduced the extraction processing time binarizes plate's template region using adaptive thresholding extracts candidate region containing plate, and verifies a final region using plate character distribution characteristics among the candidates. Experimenal results were exactly extracted the license plate region by using proposed method to the image obtained in an exclusive bus-lane with various weather and environment conditions.

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A Vehicle Detection Algorithm for a Lane Change (차선 변경을 위한 차량 탐색 알고리즘)

  • Ji, Eui-Kyung;Han, Min-Hong
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.2
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    • pp.98-105
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    • 2007
  • In this paper, we propose the method and system which determines the condition for safe and unsafe lane changing. To determine the condition, first, the system sets up the Region of Interest(ROI) on the neighboring lane. Second, a dangerous vehicle is extracted during the line changing. Third, the condition is determined to wm or not by calculating the moving direction, relative distance md relative velocity. To set up the ROI, the only one side lane is detected and the interested region is expanded. Using the coordinate transformation method, the accuracy of the ROI raised. To correctly extract the vehicle on the neighboring lane, the Adaptive Background Update method and Image Segmentation method which uses the feature of the travelling road are used. The object which is extracted by the dangerous vehicle is calculated the relative distance, the relative velocity and the moving average. And then in order to ring, the direction of the vehicle and the condition for safe and unsafe is determined. As minimizes the interested region and uses the feature of the travelling road, the computational quantity is reduced and the accuracy is raised and a stable result on a travelling road images which demands a high speed calculation is showed.

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DFT를 사용한 고속 constant modulus algorithm 의 성능분석

  • Yang, Yoon-Gi;Lee, Chang-Su;Yang, Soo-Mi
    • Journal of IKEEE
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    • v.13 no.1
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    • pp.1-10
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    • 2009
  • Recently, some frequency domain CMA (Constant Modulus Algorithm) have been introduced in an effort to reduce computational complexities [1,2]. In [1], a fast algorithm that minimizing cost function designed for block input signal is employed, while in [2], a novel cost function that minimizing sample by sample input is used. Although, the two fast algorithm save computational complexities as compared to CMA, the convergence behaviors of the two fast algorithm show different results with repsect to CMA. Thus, in this paper, some analytical results on the error surface of the fast frequency domain CMA are introduced. From the analytical results, we show that the more recent algorithm [2] outperforms the previous algorithm [1]. Simulation results reveals that the recent algorithm [2] shows 50% enhanced convergence with respect to the old fast algorithm [1]. Also, we show that the recent fast algorithm [2] has comparable convergence performance with respect to conventional CMA algorithm.

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A Study on Removing Impulse Noise using Modified Adaptive Switching Median Filter (변형된 적응 스위칭 메디안 필터를 이용한 임펄스 잡음제거에 관한 연구)

  • Gao, Yinyu;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.11
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    • pp.2474-2479
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    • 2011
  • As society has developed rapidly toward a highly advanced digital information age, a multimedia communication service for acquisition, transmission and storage of image data as well as voice has being commercialized. However, image data is always corrupted by various noises during image processing, so researches for removing noises have been continued until now. In this paper, in order to remove impulse noise we proposed modified adaptive switching median filter that consists of two stages: noise detection and noise removal. Proposed algorithm only processes noise pixels and these noise pixels are replaced by filter output, so proposed algorithm performs well not only removes noise but also preserves edge information. Also we compare existing methods using PSNR(peak signal to noise ratio) as the standard of judgement of improvement effect and choose conventional algorithms to compare with our proposed method.

A Simple Open Loop Transmit Diversity Scheme for Rician Fading Channels (라이시안 페이딩 채널을 위한 단순한 형태의 개방루프 전송 다이버시티 기법)

  • 김학성;이원철;신요안
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7B
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    • pp.695-705
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    • 2002
  • In this paper, we propose a simple open loop transmit diversity (TD) scheme for the wideband code division multiple access (W-CDMA) systems in Rician multipath fading channels such as rural area or satellite channels where line-of-sight (LOS) paths are in presence. The proposed scheme does not require any pre-processing of transmit data, resulting in simpler structure as compared to conventional closed loop transmit adaptive array (TxAA) and open loop space-time transmit diversity (STTD). We analytically derive the probability density function of signal-to-noise ratio at the Rake receiver output and the uncoded bit error rate performance of the proposed scheme. Extensive simulation is Performed to verify the analytical performance of the proposed scheme under typical Rician multipath fading channel environments. Moreover, comparative results with the conventional TxAA and STTD are also provided. Simulation results show that the proposed scheme shows slightly better performance than the conventional open loop STTD under the channels with very weak LOS components, however, it significantly outperforms the STTD under the channels with dominant LOS components, and achieves a close performance of ideal closed loop TxAA.