S. K. Pal

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In the present work, two different types of artificial neural network (ANN) architectures viz. back propagation neural network (BPNN) and radial basis function network (RBFN) have been used in an attempt to predict flank wear in drills. Flank wear in drill depends upon speed, feed rate, drill diameter and hence these parameters along with other derived(More)
Histogram equalisation has been a much sought-after technique for improving the contrast of an image, which however leads to an over enhancement of the image, giving it an unnatural and degraded appearance. In this framework, a generalised contrast enhancement algorithm is proposed which is independent of parameter setting for a given dynamic range of the(More)
Spectral analysis of Heart Rate Variability (HRV) can be used for the assessment of cardiovascular autonomic control. In this study Smoothed-Pseudo Wigner-Ville Distribution (SPWVD) has been used to evaluate the effect of local anesthesia on HRV parameters in a group of fourteen patients undergoing brachial plexus block (local anesthesia) using the(More)
The performance of two different algorithms of detrending the RR-interval before Heart Rate Variability (HRV) analysis has been evaluated using both, simulated signals and real RR-interval time series. The first algorithm is based on the Smoothness Prior Approach (SPA) and the second algorithm is implemented using Wavelet Packet (WP) analysis. The(More)
Manual differentiation of electroencephalography (EEG) paper recordings in cases of depression is not very helpful. So, a Multilayer Perceptron (MLP) has been used to differentiate the EEG power density spectra (qEEG) in the wakeful state from animals (control, exercised and depressed). The qEEG ranging from 1 to 30 Hz, at 1 Hz increments (30 input(More)
  • S. K. Pal
  • 2007
The symmetric, orthogonal and self-inverting properties of Hadamard matrices make them useful for a number of present day applications. In addition, the binary nature of elements of the basis vectors helps in the design of efficient algorithms for coding, compression and security of digital media together with their compact hardware realization. This paper(More)
Photoplethysmography (PPG) is a technique widely used to monitor volumetric blood changes induced by cardiac pulsations. Pulse oximetry uses the technique of PPG to estimate arterial oxygen saturation values ( $$\hbox{SpO}_2$$ ). In poorly perfused tissues, $$\hbox{SpO}_2$$ readings may be compromised due to the poor quality of the PPG signals. A multimode(More)
Lidar system and radio-soundings were used to validate both air-density and low and high-resolution temperature profiles of the GOMOS instrument onboard ENVISAT-1 satellite. No bias greater than 7% was found for the air-density comparisons with lidar and there is a very strong global agreement. The conditions of the occultations have a large impact on the(More)
Studies on thyroid functions were performed on patients suffering from depression and compared with normal control group. 31 different cases of depression were studied for their thyroid function andshowed a diminished level of T(3) and T(4) with a concomitant rise in TSH level. When the female population of these 31 cases was compared with their male(More)