Wavelet filter-based weak signature detection method and its application on rolling element bearing prognostics

Robust performance degradation assessment methods for enhanced rolling element bearing prognostics

A color image cryptosystem based on dynamic DNA encryption and chaos

The field of electrocardiography has been in existence for over a century, yet despite significant advances in adult clinical electrocardiography, signal processing techniques and fast digital processors, the analysis of fetal ECGs is still in its infancy. This is, partly due to a lack of availability of gold standard databases, partly due to the relatively low signal-to-noise ratio of the fetal ECG compared to the maternal ECG (caused by the various media between the fetal heart and the measuring electrodes, and the fact that the fetal heart is simply smaller), and in part, due to the less complete clinical knowledge concerning fetal cardiac function and development. In this paper we review a range of promising recording and signal processing techniques for fetal ECG analysis that have been developed over the last forty years, and discuss both their shortcomings and advantages. Before doing so, however, we review fetal cardiac development, and the etiology of the fetal ECG. A selection of relevant models for the fetal/maternal ECG mixture is also discussed. In light of current understanding of the fetal ECG, we then attempt to justify recommendations for promising future directions in signal processing, and database creation.

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A Review of Fetal ECG Signal Processing; Issues and Promising Directions.

This paper reviews the current status of principal component analysis in the area of ECG signal processing. The fundamentals of PCA are briefly described and the relationship between PCA and Karhunen-Loeve transform is explained. Aspects on PCA related to data with temporal and spatial correlations are considered as adaptive estimation of principal components is. Several ECG applications are reviewed where PCA techniques have been successfully employed, including data compression, ST-T segment analysis for the detection of myocardial ischemia and abnormalities in ventricular repolarization, extraction of atrial fibrillatory waves for detailed characterization of atrial fibrillation, and analysis of body surface potential maps.

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Principal component analysis in ECG signal processing

The extraction of fetal electrocardiogram (ECG) from the composite maternal ECG signal obtained from the abdominal lead is discussed. The proposed method employs singular value decomposition (SVD) and analysis based on the singular value ratio (SVR) spectrum. The maternal ECG (M-ECG) and the fetal ECG (F-ECG) components are identified in terms of the SV-decomposed modes of the appropriately configured data matrices, and elimination of the M-ECG and determination of F-ECG are achieved through selective separation of the SV-decomposed components. The unique feature of the method is that only one composite maternal ECG signal is required to determine the P-ECG component. The method is numerically robust and computationally efficient.

Fetal ECG extraction from single-channel maternal ECG using singular value decomposition

This paper presents a new concept of decomposition of a signal into component periodic waveforms. The singular value decomposition (SVD) is used for the detection of periodicity and separation of the component signals. The signal is configured for the sequential extraction of successively weaker components with different period lengths. The approach enjoys the numerical stability associated with SVD. >

On multiple pattern extraction using singular value decomposition

In this communication, a chaos-based symmetric key encryption of RGB color images with multiple chaotic maps and pseudorandom binary number generator (PRBNG) has been proposed. The original image is first scrambled using generalized Arnold cat map to achieve confusion. The scrambled image is then encrypted using chaotic sequences generated by multiple one-dimensional chaotic maps. Selection of the map is made pseudorandom by letting the selection be determined by the output generated by a chaos-based pseudorandom binary number generator. Encryption based on multiple chaotic maps where the choice of map is governed by the output of PRBNG leads to the most important contribution of this work: It affords a high degree of security by providing a very large key space. Statistical tests like histogram analysis, correlation coefficient analysis, measures of central tendency and dispersion along with key sensitivity test, key space analysis, information entropy test have been used. To demonstrate the efficiency and superior performance of the proposed approach as compared to existing techniques, the metrics mean squared error, peak signal-to-noise ratio, number of pixels change rate and unified average changing rate have been used for a quantified assessment of the encryption quality.

Confusion and diffusion of color images with multiple chaotic maps and chaos-based pseudorandom binary number generator

The singular value decomposition—applied in the modelling and prediction of quasiperiodic processes

Partial encryption is one of the viable solutions for low power, high speed, real time secure multimedia communication In this paper, a chaotic tent map based selective bitplane encryption technique is proposed for both gray scale and color images After decomposing the original image into eight bitplanes, each bitplane is classified into either significant or non-significant category by defining a flexible threshold value of 03, deduced experimentally Following this segregation, only the significant bitplanes are encrypted with the key stream sequences generated by a chaos-based pseudo-random binary number generator The cipher image is then transmitted through public channel The proposed scheme has three important contributions viz a) determination of significant bitplanes, b) encryption of only the significant bitplanes leading to reduction in computational complexity and c) elimination of the need for separate channel for transmitting the information about the significant bitplanes It is shown that the proposed partial encryption scheme saves around 35% computation on the image database used here Different types of attacks against this scheme are also analysed to show the robustness of this approach

Sarbani Palit

Papers

Fetal ECG extraction from single-channel maternal ECG using singular value decomposition

On multiple pattern extraction using singular value decomposition

Confusion and diffusion of color images with multiple chaotic maps and chaos-based pseudorandom binary number generator

The singular value decomposition—applied in the modelling and prediction of quasiperiodic processes

A selective bitplane image encryption scheme using chaotic maps