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V. Sadasivam - One of the best experts on this subject based on the ideXlab platform.

  • ECG Signal Coding USING BIORTHOGONAL WAVELET-BASED BURROWS–WHEELER CODER
    International Journal of Wavelets Multiresolution and Information Processing, 2011
    Co-Authors: R. Shantha Selva Kumari, R. Suriya Prabha, V. Sadasivam
    Abstract:

    Wavelets are the powerful tool for Signal processing especially bio-Signal processing. Wavelet transform is used to represent the Signal to some other time frequency representation better suited for detecting and removing redundancies. In this paper, electrocardiogram (ECG) Signal Coding using biorthogonal wavelet-based Burrows–Wheeler Coder is discussed. Biorthogonal wavelet transform is used to decompose the ECG Signal. Then the Burrows–Wheeler Coder is applied in order to compress the decomposed ECG Signal. The Burrows–Wheeler Coder is the combination of Burrows–Wheeler Transformation (BWT), Move-to-Front (MTF) coder and Huffman coder. Compression Ratio (CR) and Percent Root mean square Difference (PRD) are used as performance measures. ECG Signals/records from MIT-BIH arrhythmic database are used to evaluate the performance of this coder. This algorithm is tested with 25 different records from MIT-BIH arrhythmia database and obtained the average PRD as 0.0307% to 3.8706% for the average CR of 3.6362 : 1 to 280.48 : 1. For record 117, the CR of 8.1638 : 1 is achieved with PRD 0.1652%. This experimental results show that this coder outperforms other coders such as Djohn, EZW, SPIHT, Novel algorithm etc. that exist in the literature in terms of Coding efficiency and computation.

  • A novel algorithm for wavelet based ECG Signal Coding
    Computers & Electrical Engineering, 2007
    Co-Authors: R. Shantha Selva Kumari, V. Sadasivam
    Abstract:

    Wavelets have emerged as powerful tools for Signal Coding especially bio-Signal processing. Wavelet transform is used to represent the Signal to some other time-frequency representation better suited for detecting and removing redundancies. A novel algorithm for wavelet based ECG Signal Coding is proposed in this paper. Experimental results show that this algorithm outperforms than other coders such as Djohn, EZW, SPIHT, etc., exits in the literature in terms of simplicity and Coding efficiency by successive partition the wavelet coefficients in the space frequency domain and send them using adaptive decimal to binary conversion. Proposed algorithm is significantly more efficient in compression, simple in implementation and in computation than the previously proposed coders. This algorithm is tested for 26 different records from MIT-BIH arrhythmia database and obtained an average percent root mean square difference as around 0.01-4.8% for an average compression ratio of 2:1 to 35:1. A compression ratio of 8.5108:1 is achieved for MIT-BIH arrhythmia database record 117 with a percent mean square difference as 1.29%.

  • Successive partition zero coder for embedded lossless wavelet-based EGC Signal Coding [EGC read ECG]
    8th International Conference on Electromagnetic Interference and Compatibility, 2003
    Co-Authors: R. Shantha Selva Kumari, V. Sadasivam
    Abstract:

    Wavelets have emerged as powerful tools for Signal Coding. Wavelet transform is used to represent the Signal to some other time-frequency representation better suited for detecting and removing redundancies. Successive partition zero coder (SPZC) for embedded loss less wavelet based ECG Signal Coding which use both horizontal and vertical bit scanning is proposed. Experimental results show that SPZC outperforms than other coders such as EZW, SPIHT, LZC, etc. in terms of Coding efficiency by successive partition the wavelet coefficients in the space frequency domain. Proposed algorithm is significantly more efficient in compression and in computation than other coders exists in the literature.

  • Performance analysis of embedded lossless wavelet based successive partition zero coder for ECG Signal Coding
    Sixth International Conference on Computational Intelligence and Multimedia Applications (ICCIMA'05), 1
    Co-Authors: R. Shantha Selva Kumari, V. Sadasivam
    Abstract:

    Wavelets have emerged as powerful tools for Signal Coding. In this paper embedded lossless Wavelet based coder with hybrid bit scanning is used for ECG Signal Coding. Experimental results show that this algorithm outperforms than other coders such as Djohn, EZW, SPIHT, LJPEG etc exits in the literature in terms of Coding efficiency by successive partitioned the wavelet coefficients in the space frequency domain and sent them using hybrid bit scanning. Since no zero tree exists this coder is significantly more efficient in compression, simple in implementation and in computation than the previously proposed coders. This algorithm is tested for thirty seven different records from MIT-BIH arrhythmia database and obtained an average percent root mean square difference as around 0.0502% to 3.5399% for an average compression ratio of 1.5:1 to 25.1429:1 and for an average bit rate of 2552.7bps to 254.5 bps. A compression ratio of 8.0688:1 is achieved for MIT-BIH arrhythmia database record 117 with a percent mean square difference as 0.5183% and bit rate as 909.8 bps using Bior6.8 wavelet. All clinical information is preserved after compression and this makes the algorithm an attractive choice for use in portable heart monitoring systems.

M J T Smith - One of the best experts on this subject based on the ideXlab platform.

  • spectrum decomposition for image Signal Coding
    IEEE Transactions on Signal Processing, 2013
    Co-Authors: M J T Smith
    Abstract:

    In conventional subband/wavelet image Coding, the subband decomposition is performed on the spatial-domain image. Here, we introduce a novel decomposition where the subband decomposition is performed on the global DCT spectrum of the image. That is, the two-dimensional spectrum rather than the image is represented by a sum of basis functions, each weighted by the transform coefficients. The distinct features of this decomposition are analyzed from a transform perspective. This spectral subband decomposition is then used as the basis for a new image coder, building on the condensed wavelet packet (CWP) algorithm. Ironically, this new method is shown to have lower arithmetic complexity than conventional subband/wavelet coders that directly decompose a time or spatial domain Signal. Comparisons of the new method against conventional subband/wavelet coders that use the popular 9/7 dyadic decomposition, condensed wavelet packets, and generalized lapped orthogonal transforms, show that the new method has lower complexity and higher compression performance.

Wasfy B Mikhael - One of the best experts on this subject based on the ideXlab platform.

  • ISCAS (4) - A novel adaptive algorithm applied to a class of redundant representation vector quantizers for waveform and model based Coding
    2002 IEEE International Symposium on Circuits and Systems. Proceedings (Cat. No.02CH37353), 2002
    Co-Authors: V. Krishnan, Wasfy B Mikhael
    Abstract:

    Recently, novel vector quantization techniques in multiple nonorthogonal domains for both waveform and Linear Prediction (LP) model based, Signal characterization have been reported. This approach gives an improved Signal Coding performance as compared to vector quantization in a single domain. In these techniques, each vector, formed either directly from the Signal waveform or from the LP model coefficients extracted from the Signal, is encoded in the domain that best represents the vector. An iterative algorithm for codebook accuracy enhancement, applicable to both waveform and LP model based vector quantization in nonorthogonal domains is developed and presented in this paper. In this algorithm, in the learning mode, each set of codebooks is retrained by those training vectors that selected that particular set of codebooks in the most recent iteration. Sample results are provided which clearly demonstrate the improved performance for the same bitrate.

  • A novel adaptive algorithm applied to a class of redundant representation vector quantizers for waveform and model based Coding
    2002 IEEE International Symposium on Circuits and Systems. Proceedings (Cat. No.02CH37353), 2002
    Co-Authors: V. Krishnan, Wasfy B Mikhael
    Abstract:

    Recently, novel vector quantization techniques in multiple nonorthogonal domains for both waveform and Linear Prediction (LP) model based, Signal characterization have been reported. This approach gives an improved Signal Coding performance as compared to vector quantization in a single domain. In these techniques, each vector, formed either directly from the Signal waveform or from the LP model coefficients extracted from the Signal, is encoded in the domain that best represents the vector. An iterative algorithm for codebook accuracy enhancement, applicable to both waveform and LP model based vector quantization in nonorthogonal domains is developed and presented in this paper. In this algorithm, in the learning mode, each set of codebooks is retrained by those training vectors that selected that particular set of codebooks in the most recent iteration. Sample results are provided which clearly demonstrate the improved performance for the same bitrate.

Paola Rossi - One of the best experts on this subject based on the ideXlab platform.

  • Integrated Regulation of Signal Coding and Plasticity by NMDA Receptors at a Central Synapse
    Neural plasticity, 1998
    Co-Authors: Egidio D'angelo, Paola Rossi
    Abstract:

    The role of NMDA and non-NMDA glutamate receptors in long-term potentiation has been intensely investigated, yet recent evidence on the dynamics of synaptic depolarization suggests that the original view should be extended. NMDA receptor-mediated currents, apart from their Ca2+ permeability, show a marked voltage dependence, consisting of current increase and slowdown during membrane depolarization. During highfrequency synaptic transmission, NMDA current increase and slowdown are primed by non-NMDA receptor-dependent depolarization and proceed regeneratively. Thus, NMDA receptors make a decisive contribution to membrane depolarization and spike-firing. From the data obtained at the mossy fiber- granule cell synapse of the cerebellum, we propose that the electrogenic role of NMDA receptors is functional to LTP induction. Moreover, during LTP, both NMDA and non- NMDA receptor currents are potentiated, thus establishing a feed-forward mechanism that ultimately enhances spike firing. Thus, NMDA receptors exert an integrated control on Signal Coding and plasticity. This mechanism may have important implications for information processing at the cerebellar mossy fibergranule cell relay.

Boris V. Krylov - One of the best experts on this subject based on the ideXlab platform.

  • A novel mechanism of modulation of slow sodium channels: from ligand-receptor interaction to design of an analgesic medicine
    2014
    Co-Authors: Vera Plk, E. V. Lopatina, Ilya V. Rogachevsky, Tatiana N. Shelykh, Irina P. Butkevich, V. A. Mikhailenko, Vladimir A. Otellin, S. A. Podzorova, Boris Krylov, Boris V. Krylov
    Abstract:

    OBJECTIVES: Binding of gamma-pyrone derivatives to an opioid-like membrane receptor was shown to modulate the functional properties of Na V1.8 channels, responsible for the nociceptive Signal Coding, by a novel me

  • Mechanisms of nociceptive Signal Coding: Role of slow sodium channels
    Biochemistry (Moscow) Supplement Series A: Membrane and Cell Biology, 2009
    Co-Authors: E. V. Lopatina, V. B. Plakhova, T. N. Shelykh, Ilya V. Rogachevsky, V. A. Penniyaynen, V. A. Podzorova, Boris V. Krylov
    Abstract:

    321 Using whole-cell patch-clamp method, the rat DRG nociceptive neuron membrane was investigated. Extracellular ouabain applications lead to a decrease of the effective charge transfer in the activation gating system of the slow sodium channels (TTX r , Na v 1.8). Ouabain concentration–effective charge transfer (dose– response) dependence has U-like shape after extracellular ouabain application. Left branch of this dependence is monotonous in the range from 100 pM to 1 μ M (K d = 3 nM). Quantum-chemical calculations have shown that the ouabain molecule could effectively form the chelate complex with free calcium ion. As a result, the equilibrium geometry of this complex changes and the probable consequence of this binding is the fact that this complex better fits the transducer site of the Na + ,K + -ATPase. Besides, the chelate complex should specifically activate this transducer site due to the ionionic binding. Less specific free (without calcium) ouabain higher concentration binding takes place at the different Na + ,K + -ATPase site that probably controls its pumping function. Heterogeneity of the ouabain binding sites could explain the U-like shape of the dose– response function under investigation. The inflammatory pain test shows that injections of ouabain at low concentration (i.p., 0.3 mg/kg) lead to pain relief. We hypothesize that physiological role of the endogenous ouabain results in the decrease of nociceptive Signals. Mechanisms of Nociceptive Signal Coding: Role of Slow Sodium Channels