• Title/Summary/Keyword: Discrete signal processing

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A Study on Signal Processing Using Multiple-Valued Logic Functions (디치논리 함수를 이용한 신호처리 연구)

  • 성현경;강성수;김흥수
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.12
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    • pp.1878-1888
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    • 1990
  • In this paper, the input-output interconnection method of the multi-valued signal processing circuit using perfect Shuffle technique and Kronecker product is discussed. Using this method, the design method of circuit of the multi-valued Reed-Muller expansions(MRME) to be used the multi-valued signal processing on finite field GF(p**m) is presented. The proposed input-output interconnection method is shown that the matrix transform is efficient and that the module structure is easy. The circuit design of MRME on FG(p**m) is realized following as` 1) contructing the baisc gates on GF(3) by CMOS T gate, 2) designing the basic cells to be implemented the transform and inverse transform matrix of MRME using these basic gates, 3) interconnecting these cells by the input-output interconnecting method of the multivalued signal processing circuits. Also, the circuit design of the multi-valued signal processing function on GF(3\ulcorner similar to Winograd algorithm of 3x3 array of DFT (discrete fourier transform) is realized by interconnection of Perfect Shuffle technique and Kronecker product. The presented multi-valued signal processing circuits that are simple and regular for wire routing and posses the properties of concurrency and modularity are suitable for VLSI.

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Fast short length running FIR structure in discrete wavelet adaptive algorithm

  • Lee, Chae-Wook
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.1
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    • pp.19-25
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    • 2012
  • An adaptive system is a well-known method for removing noise from noise-corrupted speech. In this paper, we perform a least mean square (LMS) based on wavelet adaptive algorithm. It establishes the faster convergence rate of as compared to time domain because of eigenvalue distribution width. And this paper provides the basic tool required for the FIR algorithm whose algorithm reduces the arithmetic complexity. We consider a new fast short-length running FIR structure in discrete wavelet adaptive algorithm. We compare FIR algorithm and short-length fast running FIR algorithm (SFIR) to the proposed fast short-length running FIR algorithm(FSFIR) for arithmetic complexities.

A Low Frequency Band Watermarking with Weighted Correction in the Combined Cosine and Wavelet Transform Domain

  • Deb, Kaushik;Al-Seraj, Md. Sajib;Chong, Ui-Pil
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.1
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    • pp.13-20
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    • 2013
  • A combined DWT and DCT based watermarking technique of low frequency watermarking with weighted correction is proposed. The DWT has excellent spatial localization, frequency spread and multi-resolution characteristics, which are similar to the theoretical models of the human visual system (HVS). The DCT based watermarking techniques offer compression while DWT based watermarking techniques offer scalability. These desirable properties are used in this combined watermarking technique. In the proposed method watermark bits are embedded in the low frequency band of each DCT block of selected DWT sub-band. The weighted correction is also used to improve the imperceptibility. The extracting procedure reverses the embedding operations without the reference of the original image. Compared with the similar approach by DCT based approach and DWT based approach, the experimental results show that the proposed algorithm apparently preserves superiori mage quality and robustness under various attacks such as JPEG compression, cropping, sharping, contrast adjustments and so on.

A Study on Threshold-based Denoising by UDWT (UDWT을 이용한 경계법에 기초한 노이즈 제거에 관한 연구)

  • 배상범;김남호;류지구
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.77-80
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    • 2001
  • This paper presents a new threshold-based denoising method by using undecimated discrete wavelet transform (UDWT). It proved excellency of the UDWT compared with orthogonal wavelet transform (OWT), spatia1ly selective noise filtration (SSNF) and NSSNF added new parameter. Methods using the spatial correlation are effectual at edge detection and image enhancement, whereas algorithm is complex and needs more computation However, UDWT is effective at denoising and needs less computation and simple algorithm.

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Improvement in computing times by the elimination of redundancies in existing DFT and FFT (DFT 및 FFT에 있어서의 Redundancies와 그의 제거에 의한 Fourier 변환고속화)

  • 안수길
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.14 no.6
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    • pp.26-30
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    • 1977
  • Redundancies in the Calculation of DFT and FFT are analized and new algorithms are proposed which are capable of reducing the machine time by a considerable amount. New extensions of T.D C.F. and T.D.F.T. are given for the discrete case which permit a deeper insights for the techniques of digital signal Proessing i. e. Discrete Fourier Transform, Convolution Sum and Correlation sequences.

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The Digital Image Processing Method Using Triple-Density Discrete Wavelet Transformation (3중 밀도 이산 웨이브렛 변환을 이용한 디지털 영상처리 기법)

  • Shin, Jong Hong
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.3
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    • pp.133-145
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    • 2012
  • This paper describes the high density discrete wavelet transformation which is one that expands an N point signal to M transform coefficients with M > N. The double-density discrete wavelet transform is one of the high density discrete wavelet transformation. This transformation employs one scaling function and two distinct wavelets, which are designed to be offset from one another by one half. And it is nearly shift-invariant. Similarly, triple-density discrete wavelet transformation is a new set of dyadic wavelet transformation with two generators. The construction provides a higher sampling in both time and frequency. Specifically, the spectrum of the first wavelet is concentrated halfway between the spectrum of the second wavelet and the spectrum of its dilated version. In addition, the second wavelet is translated by half-integers rather than whole-integers in the frame construction. This arrangement leads to high density wavelet transformation. But this new transform is approximately shift-invariant and has intermediate scales. In two dimensions, this transform outperforms the standard and double-density discrete wavelet transformation in terms of multiple directions. Resultingly, the proposed wavelet transformation services good performance in image and video processing fields.

High Embedding Capacity and Robust Audio Watermarking for Secure Transmission Using Tamper Detection

  • Kaur, Arashdeep;Dutta, Malay Kishore
    • ETRI Journal
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    • v.40 no.1
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    • pp.133-145
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    • 2018
  • Robustness, payload, and imperceptibility of audio watermarking algorithms are contradictory design issues with high-level security of the watermark. In this study, the major issue in achieving high payload along with adequate robustness against challenging signal-processing attacks is addressed. Moreover, a security code has been strategically used for secure transmission of data, providing tamper detection at the receiver end. The high watermark payload in this work has been achieved by using the complementary features of third-level detailed coefficients of discrete wavelet transform where the human auditory system is not sensitive to alterations in the audio signal. To counter the watermark loss under challenging attacks at high payload, Daubechies wavelets that have an orthogonal property and provide smoother frequencies have been used, which can protect the data from loss under signal-processing attacks. Experimental results indicate that the proposed algorithm has demonstrated adequate robustness against signal processing attacks at 4,884.1 bps. Among the evaluators, 87% have rated the proposed algorithm to be remarkable in terms of transparency.

Noise Reduction for Photon Counting Imaging Using Discrete Wavelet Transform

  • Lee, Jaehoon;Kurosaki, Masayuki;Cho, Myungjin;Lee, Min-Chul
    • Journal of information and communication convergence engineering
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    • v.19 no.4
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    • pp.276-283
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    • 2021
  • In this paper, we propose an effective noise reduction method for photon counting imaging using a discrete wavelet transform. Conventional 2D photon counting imaging was used to visualize the object under dark conditions using statistical methods, such as the Poisson random process. The photons in the scene were estimated using a statistical method. However, photons which disturb the visualization and decrease the image quality may occur in the background where there is no object. Although median filters are used to reduce the noise, the noise in the scene remains. To remove the noise effectively, our proposed method uses the discrete wavelet transform, which removes the noise in the scene using a specific thresholding method that utilizes photon counting imaging characteristics. We conducted an optical experiment to demonstrate the denoising performance of the proposed method.

Speech Query Recognition for Tamil Language Using Wavelet and Wavelet Packets

  • Iswarya, P.;Radha, V.
    • Journal of Information Processing Systems
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    • v.13 no.5
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    • pp.1135-1148
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    • 2017
  • Speech recognition is one of the fascinating fields in the area of Computer science. Accuracy of speech recognition system may reduce due to the presence of noise present in speech signal. Therefore noise removal is an essential step in Automatic Speech Recognition (ASR) system and this paper proposes a new technique called combined thresholding for noise removal. Feature extraction is process of converting acoustic signal into most valuable set of parameters. This paper also concentrates on improving Mel Frequency Cepstral Coefficients (MFCC) features by introducing Discrete Wavelet Packet Transform (DWPT) in the place of Discrete Fourier Transformation (DFT) block to provide an efficient signal analysis. The feature vector is varied in size, for choosing the correct length of feature vector Self Organizing Map (SOM) is used. As a single classifier does not provide enough accuracy, so this research proposes an Ensemble Support Vector Machine (ESVM) classifier where the fixed length feature vector from SOM is given as input, termed as ESVM_SOM. The experimental results showed that the proposed methods provide better results than the existing methods.

The identification of continuous-time systems within a closed-loop

  • Bae, Chul-Min;Wada, Kiyoshi;Imai, Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.157-160
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    • 1996
  • Physical systems axe generally continuous-time in nature. However as the data measured from these systems is generally in the form of discrete samples, and most modern signal processing is performed in the discrete-time domain, discrete-time models are employed. This paper describes methods for estimating the coefficients of continuous-time system within a closed loop control system. The method employs a recursive estimation algorithm to identify the coefficients of a discrete-time bilinear-operator model. The coefficients of the discrete-time bilinear-operator model closely approximate those of the corresponding continuous-time Laplace transform transfer function.

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