Faculty Publications
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Item COVID-19 detection from spectral features on the DiCOVA dataset(International Speech Communication Association, 2021) Ritwik, K.V.S.; Kalluri, S.B.; Vijayasenan, D.In this paper we investigate the cues of COVID-19 on sustained phonation of Vowel-/i/, deep breathing and number counting data of the DiCOVA dataset. We use an ensemble of classifiers trained on different features, namely, super-vectors, formants, harmonics and MFCC features. We fit a two-class Weighted SVM classifier to separate the COVID-19 audio from Non-COVID-19 audio. Weighted penalties help mitigate the challenge of class imbalance in the dataset. The results are reported on the stationary (breathing, Vowel-/i/) and nonstationary( counting data) data using individual and combination of features on each type of utterance. We find that the Formant information plays a crucial role in classification. The proposed system resulted in an AUC score of 0.734 for cross validation, and 0.717 for evaluation dataset. © © 2021 ISCA.Item Physico-chemical, acoustic and excess properties of glycylglycine-MnCl2 in aqueous ethanol mixtures at different temperatures(2010) Santosh, M.S.; Bhatt, A.S.; Bhat, D.K.Volumetric, acoustic, refractometric, excess and deviation properties of glycylglycine-MnCl2 in aqueous ethanol mixtures have been reported at T = (288.15 to 318.15) K. Redlich-Kister equation was used to fit the derivate properties. The experimental data of the constituent binaries were analyzed to discuss the nature and strengths of intermolecular interactions. The interdependence of Lf and u has been evolved from Eyring and Kincaid model. The variations in specific acoustic impedance revealed that hydrogen bonding was predominant in the studied binary mixtures. Solvation number indicated structure-breaking tendency of the solute and weakening of local solvent structure. © 2010 Elsevier B.V. All rights reserved.Item Sound radiation and transmission loss characteristics of a honeycomb sandwich panel with composite facings: Effect of inherent material damping(Academic Press, 2016) Arunkumar, M.P.; Jagadeesh, M.; Jeyaraj, J.; Gangadharan, K.V.; Mailan Chinnapandi, M.C.L.This paper presents the results of numerical studies carried out on vibro-acoustic and sound transmission loss behaviour of aluminium honeycomb core sandwich panel with fibre reinforced plastic (FRP) facings. Layered structural shell element with equivalent orthotropic elastic properties of core and orthotropic properties of FRP facing layer is used to predict the free and forced vibration characteristics. Followed by this, acoustic response and transmission loss characteristics are obtained using Rayleigh integral. Vibration and acoustic characteristics of FRP sandwich panels are compared with aluminium sandwich panels. The result reveals that FRP panel has better vibro-acoustic and transmission loss characteristics due to high stiffness and inherent material damping associated with them. Resonant amplitudes of the response are fully controlled by modal damping factors calculated based on modal strain energy. It is also demonstrated that FRP panel can be used to replace the aluminium panel without losing acoustic comfort with nearly 40 percent weight reduction. © 2016 Elsevier LtdItem Agile and cost-effective ultrasonic module for people with visual impairment using a headphone jack: Implications for enhancing mobility aids(SAGE Publications Ltd, 2017) Keerthi Vasan, G.C.; Suresh, B.; Muniyandi, M.Over 80% of the world’s people with visual impairment are living in countries which are financially dire. And over 50% of them are above the age of 50 years. The need for a system or of technology that would enable this sector of people to perceive the world in much the same way as the rest of us is imminent. The article presents a novel way to eliminate the use of data acquisition system (DAQ) systems/micro-controllers by incorporating a headphone jack. With the aid of a headphone jack, a cost-effective wearable ultrasonic module that would enable people with visual impairment to virtually see is implemented. Unlike conventional walking canes or its derivatives that do not offer effective feedback, the ingenuity in the proposed module is that it offers audible feedback to the user. The ultrasonic sensor is coupled with the headphone jack and the output of the sensor is relayed to the earphones with the help of a free mobile app (Mic To Speaker). This substantially reduces the cost of the module (since no DAQs/micro-controllers are used) and the processing needed as well. © The Author(s) 2017.Item Design of Collision Detection System for Smart Car Using Li-Fi and Ultrasonic Sensor(Institute of Electrical and Electronics Engineers Inc., 2018) Krishnan, K.The 21st century is defined as the era of technological development. With drastic increase in population, automation is becoming the need of the hour in order to make life more comfortable and easy. Due to the advancement and development in the field of automation and embedded system, the notion of smart car has become very popular. Smart cars are modernizing trends in the traditional automobile industry. Companies across the globe have been investing a huge amount of resources on the production and design of smart cars. Every technological development needs to overcome certain obstacles, and hence, in this paper, a design of a collision detection system for smart car using light fidelity (Li-Fi) and ultrasonic sensor on the Arduino platform is proposed. This design consists of an ultrasonic sensor, an Arduino processor, and a Li-Fi circuit. The ultrasonic is used for measurement of distance between vehicles, and Arduino processes the data and makes decisions accordingly. Data transmission between vehicles is ensued using a Li-Fi transmitter circuit and a Li-Fi receiver circuit. The transmitter circuit is mounted on the tail lights of the leading car and the receiver circuit is mounted on the front side of the car that follows. Using visible light communication, the transmitter circuit transmits the calculated speed and the information is received by the receiver circuit of the second car. On the basis of the information received, the speed of the second car is changed in order to avoid collision. In this paper, a system that can detect and thus avoid collision between vehicles and prevent accidents is proposed and studied. © 1967-2012 IEEE.Item Numerical Analysis on Vibro-Acoustic Behavior of Honeycomb Core Sandwich Structure with FG-CNT-Reinforced Polymer Composite Facings(Institute for Ionics, 2022) Bhagat, V.S.; George, N.; Arunkumar, M.P.; Jeyaraj, J.; Mailan Chinnapandi, M.C.L.Numerical studies carried out on the vibro-acoustic characteristics of an aluminum honeycomb core sandwich structure with functionally graded carbon nanotube polymer composite facings are presented. The layer-by-layer technique is used to model the structure by finding the equivalent elastic properties. From the vibration response, the acoustic characteristic of the honeycomb structure is found by using kinematic continuity between structural velocity and particle velocity at the surface. Forced vibration response of a hexagonal honeycomb sandwich structure is calculated experimentally, and results are compared with the proposed numerical method. Further, the result reveals that the FG-VΛ structure has better vibro-acoustic characteristics rather than FG-XX which gives better acoustic properties when it is considered as a plate without sandwich construction. © 2021, Shiraz University.