Faculty Publications
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Item Worldwide, increasingly stringent regulations are coming into force, limiting the exposure of workers to industrial noise. Industrial noise and its consequences are thus growing in importance to employers, local and central government officials, trade unions, occupational hygienists and physicians and insurers. India is not an exception to this. The mining industry in India is facing serious problems over noise due to increasing demand for minerals for which large capacity machines are being deployed producing high noise levels. To know the status and to control the noise, the S&T Department of the Ministry of Coal, Government of India sponsored a research project in the area of noise pollution and its control for opencast projects. To start with, a detailed literature survey was carried out in the area of noise pollution and its control in the mining industry, embracing equipment like from Heavy Earth Moving Machinery (HEMM), compressors, workshops, pneumatic drills, processing plants etc, to know the quantum of work done in and worldwide. The various aspects studied In this project were the daily noise dose and/or noise exposure level of the operators of various types of heavy earth moving machinery and its assessment, noise characteristics at different operating conditions of the machine, analysis of noise coming out from different parts of the machine, analysis of noise at different distances from the machine for different frequency components and the most important one i.e., impact of periodic maintenance on the noise characteristics of machines and to find out with which maintenance schedule there is maximum fluctuation in the noise level and to evolve a technique for attenuating the noise generated from these machines as well as to reduce the operator's exposure to high noise levels. This paper highlights the results of this research project.(Multi-Science Publishing Co. Ltd, Noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation - Part 3) Vardhan, H.; Rao, Y.V.; Karmakar, N.C.2004Item Worldwide, increasingly stringent regulations are coming into force, limiting the exposure of workers to industrial noise. Industrial noise and its consequences is thus growing in importance to employers, local and central government officials, trade unions, occupational hygienists and physicians and insurers. India is not an exception for this. The mining industry in India is facing serious problem of noise due to increasing demand for minerals for which large capacity machines are being deployed producing high noise levels. To know the status and to control the noise, the S&T Department of the Ministry of Coal, Government of India sponsored a research project in the area of noise pollution and its control for opencast projects. To start with, a detailed literature survey was carried out in the area of noise pollution and its control in the mining industry, embracing equipment like from Heavy Earth Moving Machinery (HEMM), compressors, workshops, pneumatic drills, processing plants etc., to know the quantum of work done in India and worldwide. The various aspects studied in this project were the daily noise dose and/or noise exposure level of the operators of various types of heavy earth moving machinery and its assessment, noise characteristics at different operating conditions of the machine, analysis of noise coming out from different parts of the machine, analysis of noise at different distances from the machine for different frequency components and the most important one i e, impact of periodic maintenance on the noise characteristics of machines and to find out with which maintenance schedule there is maximum fluctuation in the noise level and to evolve a technique for attenuating the noise generated from these machines as well as to reduce the operator's exposure to high noise levels. This paper highlights the results of this research project.(Multi-Science Publishing Co. Ltd, Noise analysis of heavy earth moving machinery deployed in opencast mines and development of suitable maintenance guidelines for its attenuation - Part 1) Vardhan, H.; Rao, Y.V.; Karmakar, N.C.2004Item Stability of breakwater defenced by a seaward submerged reef(2006) Shirlal, K.G.; Rao, S.; Ganesh, V.; Rao, M.The stability of a uniformly sloped conventional rubble mound breakwater defenced by a seaward submerged reef is investigated using physical model studies. Regular waves of wide ranging heights and periods are used. Tests are carried out for different spacings between two rubble mound structures (X/d=2.5-13.33) and for different relative heights (h/d=0.625-0.833) and relative widths (B/d=0.25-1.33) of the reef. It is observed that a reef of width (B/d) of 0.6-0.75 constructed at a seaward distance (X/d) of 6.25-8.33 breaks all the incoming waves and dissipates energy and protects the breakwater optimally. © 2005 Elsevier Ltd. All rights reserved.Item Strong Motion Data Based Regional Ground Motion Prediction Equations for North East India Based on Non-Linear Regression Models(Taylor and Francis Ltd., 2022) Ramkrishnan, R.; Kolathayar, S.; Sitharam, T.G.Existing Ground Motion Prediction Equations (GMPE) in practice for North East India have been developed using limited or simulated datasets of recorded ground motions. The current study presents the development of a new GMPE based on a well-established model considering actual recorded ground motion data comprising of acceleration, magnitude, and hypocentral distances. A larger dataset with magnitudes ranging from 4.2 to 6.9 and up to 640 kms, with a total of 204 recordings is used in non-linear multiple-regression. The newly developed GMPE could predict ground acceleration realistically over larger ranges of distance and magnitudes, compared to existing GMPEs. © 2020 Taylor & Francis Group, LLC.Item Performance enhancement of FSO communication system using machine learning for 5G/6G and IoT applications(Elsevier GmbH, 2022) Kumar, L.J.S.; Krishnan, P.; Shreya, B.; Sudhakar, S.6G networks will provide extremely high capacity and will support a wide range of new applications in the future, but the existing frequency bands may not be sufficient. Furthermore, because traditional wireless communications are incapable of providing high-speed data rates, 6G enables superior coverage by integrating space/air/underwater networks with terrestrial networks. 5G-and-beyond (5 GB) and 6G networks have been mandated as a paradigm shift to take the enhanced broadband, massive access, and ultra-reliable and low latency services of 5G wireless networks to an even more advanced and intelligent level, to meet the ever-growing quantities of demanding services. In 5G and 6G wireless communication systems, artificial intelligence (AI), particularly machine learning (ML), has emerged as an essential component of fully intelligent network orchestration and management. 5 GB and 6G communication systems will also rely heavily on a tactile Internet of Things (IoT). The diverse nature of heterogeneous traffic and the established service quality parameters in 5 GB networks will present numerous challenges. Many other wireless technologies, including free space optics (FSO), look promising for meeting the demands of 5 GB systems. FSO has been identified as a promising technology for achieving higher data rates while consuming less power. However, attenuation due to weather, pointing errors, and turbulences limits its performance. Traditional Maximum likelihood decoding techniques require prior channel information to decode the signals. in this paper, first time we proposed a novel decoding technique for decoding on–off keying (OOK) modulated FSO signals using support vector machines (SVM). The model is tested under various atmospheric weather conditions such as fog, rain, and snow, as well as turbulence and pointing errors. Simulated numerical results demonstrate that the proposed SVM-based decoding schemes are capable of mitigating attenuation, pointing error, and turbulent channel impairments. © 2021 Elsevier GmbHItem Performance Analysis of MIMO-EGC System for the Underwater Vertical Wireless Optical Communication Link(Institute of Electrical and Electronics Engineers Inc., 2023) Savidhan Shetty, S.C.S.; Naik, R.P.; Shripathi Acharya, U.S.; Chung, W.-Y.In this paper, we have investigated the performance of an underwater vertical wireless optical communication (UVWOC) link employing multiple input-multiple output (MIMO) operating in conjunction with equal gain combing (EGC) techniques perturbed by weak and strong turbulence in the presence of pointing errors and attenuation losses. Vertical underwater turbulence, which varies from layer to layer due to temperature and salinity variation connected to depth, is modeled using hyperbolic tangent log-normal (HTLN) distribution in the case of weak underwater turbulence and gamma-gamma (GG) distribution in the case of strong underwater turbulence. Novel closed-form expressions quantifying the average bit error rate (BER) have been derived for the UVWOC MIMO EGC system for weak and strong turbulence regimes. The expression for the average BER associated with the UVWOC link for different values of pointing error, differing vertical layer depth, modulation types, and differing numbers of sources and detectors have been determined. In addition, closed-form expressions for the outage probability (OP) and ergodic channel capacity (ECC) have been derived for the UVWOC MIMO EGC system. The accuracy of all closed-form expressions derived in the paper has been verified using Monte Carlo simulations. © 2013 IEEE.Item Multiuser Data Transmission Aided by Simultaneous Transmit and Reflect Reconfigurable Intelligent Surface in Underwater Wireless Optical Communications(Institute of Electrical and Electronics Engineers Inc., 2024) Naik, R.P.; Salman, M.; Bolboli, J.; Savidhan Shetty, C.S.; Chung, W.-Y.Recent research in the wireless communications field has focused on the reconfigurable intelligent surface (RIS), which can enhance energy and spectrum efficiency by reconfiguring radio waves to propagate in a specific direction. In this study, we applied the simultaneous transmit and reflect (STAR)-RIS to an underwater wireless optical communication (UWOC) system. In contrast to a conventional RIS, a STAR-RIS allows multiple users to transfer data simultaneously in all directions by obtaining a UWOC channel despite underwater turbulence, beam attenuation, blockage, and pointing errors. Underwater turbulence-induced fading was obtained by using exponential and generalized Gamma distributions, and numerical analysis were performed to evaluate the outage probability, bit error rate (BER), and channel capacity of a direct UWOC channel, conventional RIS assisted UWOC channel, and STAR-RIS assisted UWOC channel. The BER performance was also evaluated according to the number of reflective elements, type of modulation scheme, impact of pointing errors, blockage levels, and varying the transmit-reflection coefficient. Monte-Carlo simulations were performed to validate the analytical results for the BER and outage probability with respect to the average signal-to-noise ratio. Experiments were performed to demonstrate the received luminous intensity performance with respect to the incident beam luminous intensity of the proposed STAR-RIS assisted UWOC channel. © 1967-2012 IEEE.