Goutam Saha

Bio: Goutam Saha is an academic researcher from North Eastern Hill University. The author has contributed to research in topic(s): Speaker recognition & Gene regulatory network. The author has an hindex of 13, co-authored 143 publication(s) receiving 583 citation(s). Previous affiliations of Goutam Saha include Indian Institute of Technology Kharagpur & West Bengal University of Technology.

Blockchain‐based security aspects in heterogeneous Internet‐of‐Things networks: A survey

Abstract: Blockchain is a key technology that enables cryptocurrencies such as Bitcoin, Litecoin, etc. In recent years, researchers have ventured into tapping the potential of blockchain‐based ecosy...

Multichannel lung sound analysis for asthma detection.

Abstract: Background and objective Lung sound signals convey valuable information of the lung status. Auscultation is an effective technique to appreciate the condition of the respiratory system using lung sound signals. The prior works on asthma detection from lung sound signals rely on the presence of wheeze. In this paper, we have classified normal and asthmatic subjects using advanced signal processing of posterior lung sound signals, even in the absence of wheeze. Methods We collected lung sounds of 60 subjects (30 normal and 30 asthma) using a novel 4-channel data acquisition system from four different positions over the posterior chest, as suggested by the pulmonologist. A spectral subband based feature extraction scheme is proposed that works with artificial neural network (ANN) and support vector machine (SVM) classifiers for the multichannel signal. The power spectral density (PSD) is estimated from extracted lung sound cycle using Welch’s method, which then decomposed into uniform subbands. A set of statistical features is computed from each subband and applied to ANN and SVM classifiers to classify normal and asthmatic subjects. Results In the first part of this study, the performances of each individual channel and four channels together are evaluated where the combined channel performance is found superior to that of individual channels. Next, the performances of all possible combinations of the channels are investigated and the best classification accuracies of 89.2( ± 3.87)% and 93.3( ± 3.10)% are achieved for 2-channel and 3-channel combinations in ANN and SVM classifiers, respectively. Conclusions The proposed multichannel asthma detection method where the presence of wheeze in lung sound is not a necessary requirement, outperforms commonly used lung sound classification methods in this field and provides significant relative improvement. The channel combination study gives insight into the contribution of respective lung sound collection areas and their combinations in asthma detection.

Construction of Gene Regulatory Networks Using Recurrent Neural Networks and Swarm Intelligence.

Abstract: We have proposed a methodology for the reverse engineering of biologically plausible gene regulatory networks from temporal genetic expression data. We have used established information and the fundamental mathematical theory for this purpose. We have employed the Recurrent Neural Network formalism to extract the underlying dynamics present in the time series expression data accurately. We have introduced a new hybrid swarm intelligence framework for the accurate training of the model parameters. The proposed methodology has been first applied to a small artificial network, and the results obtained suggest that it can produce the best results available in the contemporary literature, to the best of our knowledge. Subsequently, we have implemented our proposed framework on experimental (in vivo) datasets. Finally, we have investigated two medium sized genetic networks (in silico) extracted from GeneNetWeaver, to understand how the proposed algorithm scales up with network size. Additionally, we have implemented our proposed algorithm with half the number of time points. The results indicate that a reduction of 50% in the number of time points does not have an effect on the accuracy of the proposed methodology significantly, with a maximum of just over 15% deterioration in the worst case.

Performance comparison of speaker recognition systems in presence of duration variability

Abstract: Performance of speaker recognition system is highly dependent on the amount of speech data used in training and testing. In this paper, we compare the performance of two different speaker recognition systems in presence of utterance duration variability. The first system is based on state-of-the-art total variability (also known as i-vector system), whereas the other one is classical speaker recognition system based on Gaussian mixture model with universal background model (GMM-UBM). We have conducted extensive experiments for different cases of length mismatch on two NIST corpora: NIST SRE 2008 and NIST SRE 2010. Our study reveals that the relative improvement of total variability based system gradually drops with the reduction in test utterance length. We also observe that if the speakers are enrolled with sufficient amount of training data, GMM-UBM system outperforms i-vector system for very short test utterances.

Classification of coronary artery diseased and normal subjects using multi-channel phonocardiogram signal

Abstract: Coronary artery disease (CAD) is one of the leading causes of mortality and morbidity. There is a need to develop a simple, reliable, and non-invasive screening tool to diagnose CAD. Prior studies reported that turbulent blood flow due to stenosed coronary arteries causes weak CAD murmurs. Analysis of phonocardiogram (PCG) signals can be useful to detect these murmurs. In this work, we propose a new multi-channel PCG-based system to classify CAD-affected and normal subjects, and it does not require any additional reference signal, such as an electrocardiogram (ECG) signal. The proposed system simultaneously acquires PCG signals from four different auscultation sites on the chest. It extracts five different features from time and frequency domains of the PCG signals. The two-class classification is done in a machine learning framework by employing an artificial neural network (ANN) classifier. The classification performances are evaluated for each channel as well as for their combinations. Experimental results show that the proposed sub-band-based spectral features perform well for both clean and noisy data. An accuracy of 82.57% is obtained using the combination of the signals acquired from tricuspid, mitral, and midaxillary regions. The multi-channel system gives more than 4% relative improvement over the best performance obtained by its single-channel counterpart, and the proposed features outperform earlier used features.

A review of imperative technologies for wastewater treatment I: oxidation technologies at ambient conditions

Abstract: Nowadays, due to the increasing presence of molecules, refractory to the microorganisms in the wastewater streams, the conventional biological methods cannot be used for complete treatment of the effluent and hence, introduction of newer technologies to degrade these refractory molecules into smaller molecules, which can be further oxidized by biological methods, has become imperative. The present work aims at highlighting five different oxidation processes operating at ambient conditions viz. cavitation, photocatalytic oxidation, Fenton's chemistry (belonging to the class of advanced oxidation processes) and ozonation, use of hydrogen peroxide (belonging to the class of chemical oxidation technologies). The work highlights the basics of these individual processes including the optimum operating parameters and the reactor design aspects with a complete overview of the various applications to wastewater treatment in the recent years. In the next article of this two article series on imperative technologies, hybrid methods (basically combination of the oxidation processes) will be discussed and the current work forms a useful foundation for the work focusing on hybrid technologies.

A review of imperative technologies for wastewater treatment II: hybrid methods

Abstract: In the first part of this two article series on the imperative technologies for wastewater treatment, a review of oxidation processes operating at ambient conditions was presented It has been observed that none of the methods can be used individually in wastewater treatment applications with good economics and high degree of energy efficiency Moreover, the knowledge required for the large-scale design and application is perhaps lacking In the present work, an overview of hybrid methods (the majority are a combination of advanced oxidation processes) has been presented Hybrid methods viz Ultrasound/H2O2 or ozone, UV/H2O2 or ozone, Ozone/H2O2, Sono-photochemical oxidation, Photo–Fenton processes, catalytic advanced oxidation processes, use of advanced oxidation processes in conjunction with biological oxidation, SONIWO (sonochemical degradation followed by wet air oxidation), and CAV-OX have been discussed with specific reference to the principles behind the expected synergism, different reactor configurations used and optimum considerations for the operating and geometric parameters An overview of different chemicals degraded has been presented Some of the important works evaluating the application of these processes to real effluents have been described in detail Some guidelines for the future work required to facilitate efficient large-scale operation have been given A model effluent treatment scheme based on the various techniques discussed in the present work has been presented

The working brain (an introduction to neuropsychology)

Abstract: CLINICAL NEUROSURGERY Edited by Barnes Wordall. Vol. 18. (Pp. 557; illustrated; £8 25.) Churchill Livingstone: Edinburgh. 1971. CLINICAL NEUROSURGERY Edited by G. T. Tindall. Vol. 19. (Pp. 598; illustrated; £12.) Churchill Livingstone: Edinburgh. 1972. The Congress of Neurosurgeons began in 1951 on the initiative of a group of younger neurosurgeons. In the last 20 years its membership has grown from 69 to over 1,000, but it has retained its original intentions and virility by a constitution which ensured that the office bearers and organizers were always young men. Residents in training are encouraged to join, financial concessions make it possible for them to attend meetings, and these are organized as an educational exercise, by inviting established authorities to give lectures on selected topics, chosen to provide a balanced programme. As a result Clinical Neurosurgery is a valuable volume which all neurosurgeons look forward to each year; it is in quite a different class from the usual conference tome, full of brief and unconnected papers of widely varying quality. As the title suggests Clinical Neurosurgery includes excellent clinical reviews but the two recent volumes include also a section of seminars on fundamental research-in volume 18 on coma and sleep, in volume 19 on basic mechanisms of memory. It is also the custom to invite a senior neurosurgical citizen as guest of honour and his two or three papers afford an opportunity for historical and philosophical reflections as well as an experienced perspective on clinical and experimental work. Add to this the refreshing presidential address, from one of the (angry?) young men of neurosurgery and it will be clear that these volumes really do include something of interest for every neurosurgeon, whatever his own interests or prejudices. It is a relief to be able so warmly to recommend these books, when the question posed by so many other books is whether anyone would really want to read them. The most recent volume has a more consistent theme than former ones, and that is 'head injury'. It includes papers on mechanisms as revealed by animal experiment and by a pathologist who visited the scene of the accident before examining the brains of head injury fatalities. There are chapters on engineering and socio-psychological aspects of accident prevention, as well as down to earth clinical accounts of metabolic disorders, testing for acoustic vestibular 36 damage, and aspects of prognosis. This is a significant contribution to the literature on head injury.

A review of applications of cavitation in biochemical engineering/biotechnology

Abstract: Cavitation results in the generation of hot spots, highly reactive free radicals, and turbulence associated with liquid circulation currents, which can result in the intensification of various physical/chemical operations. The present work provides an overview of the applications of the cavitation phenomenon in the specific area of biochemical engineering/biotechnology, discussing the areas of application, the role of cavitation, the observed enhancement and its causes by highlighting some typical examples. The different methods of inducing cavitation and the dominance of one over the other, mostly with respect to energy requirements, in different areas of biotechnological application are discussed. The major applications discussed in the work include microbial cell disruption for the release or extraction of enzymes, microbial disinfection, wastewater treatment, crystallization, synthesis of biodiesel, emulsification, extraction of bio-components, freezing and gene transfer into cells or tissues. Some recommendations for optimal operating/geometric parameters have also been made. Overall, it appears that the combined efforts of physicists, chemists, biologists and chemical engineers are required to effectively use cavitational reactors for industrial applications.

Recent Advances in the Synthesis of Cyclobutanes by Olefin [2+2] Photocycloaddition Reactions

Abstract: The [2 + 2] photocycloaddition is undisputedly the most important and most frequently used photochemical reaction. In this review, it is attempted to cover all recent aspects of [2 + 2] photocycloaddition chemistry with an emphasis on synthetically relevant, regio-, and stereoselective reactions. The review aims to comprehensively discuss relevant work, which was done in the field in the last 20 years (i.e., from 1995 to 2015). Organization of the data follows a subdivision according to mechanism and substrate classes. Cu(I) and PET (photoinduced electron transfer) catalysis are treated separately in sections 2 and 4, whereas the vast majority of photocycloaddition reactions which occur by direct excitation or sensitization are divided within section 3 into individual subsections according to the photochemically excited olefin.