Browsing by Author "Kamath, N."

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Data-Driven Inference of Fluid Properties Using Structural Response Signature
(Institute of Physics, 2025) Hetalkumar, V.S.; Kamath, N.; Gudi, O.; Gangadharan, G.
The non-invasive and accurate estimation of fluid properties using minimal sample volumes holds significant importance across industrial, biomedical, and scientific applications. This study presents a novel approach for predicting fluid properties by analysing the dynamic vibrational response of a cantilever beam interacting with liquids. The methodology employs advanced signal processing techniques, including non-dimensional feature engineering, to extract meaningful patterns from frequency response data. Two machine learning approaches - polynomial regression and the Random Convolutional Kernel Transform (ROCKET) - are utilized to model the relationship between vibrational characteristics and fluid parameters. Furthermore, symbolic regression is applied to derive a mathematical expression linking the system's damping ratio to the fluid's viscosity and density. The developed models demonstrate excellent predictive performance, as validated through the test liquid dataset. Beyond immediate applications in fluid characterization, this work provides a proof of concept to the broader field of lab-on-a-chip technologies by offering a compact, efficient, and high-precision diagnostic platform. The proposed framework combines the advantages of mechanical sensing with data-driven modelling, paving the way for real-time fluid analysis in resource-constrained environments. Â© Published under licence by IOP Publishing Ltd.
Design and experimental analysis of a non-magnetic cantilever beam in a remotely controlled free vibration setup using LabVIEW
(American Institute of Physics, 2025) Bidari, L.; Kamath, N.; Kaup, P.S.; Swamy, K.B.M.; Kalluvalappil, G.
Free vibration analysis finds a plethora of applications in real-world systems, ranging from deciding design factors to addressing maintenance concerns; hence, it forms a fundamental basis of material sciences and structural engineering. Cantilever structures are widespread across various physical systems, from domestic applications such as diving boards or parking shields to heavy-duty industrial applications such as airplane wings or windmill blades. In this paper, a non-magnetic cantilever beam is excited using a cam attached to a stepper motor. The trigger results in free vibrations of the cantilever beam and this data is collected by the accelerometer. The entire experiment is carried out distantly using LabVIEW remote panels, and frequency analysis and calculations are performed on the vibration data collected. The designed remote experimental setup provided near-accurate results for natural frequency calculation, and this is validated experimentally using an impact hammer and theoretically using physical parameters. The remote setup provides the freedom to model and simulate different physical conditions and systems as cantilever structures in the experimental environment. This results in an easy understanding of beam behavior in real-time systems. Â© 2025 Author(s).
Detecting laughter: Towards building a humorous machine
(2006) Kamath, N.
Laughter is a common social gesture which often indicates the presence of humor. Detecting laughter and then understanding humor can make machines interact with us in a more natural way. This paper presents an algorithm to automatically detect laughter segments in speech. The voiced laughter of the speaker is recognized and the approximate onsets of the laughter bouts are used to annotate stored conversations. A simple algorithm based on the acoustic properties of voiced laughter is proposed and implemented for the same. The algorithm is able to detect the segments of laughter bouts in data consisting of sentences obtained from the switchboard corpus with an accuracy rate of 77.41% and a false detection rate of 12.90%.
Detecting laughter: Towards building a humorous machine
(2006) Kamath, N.
Laughter is a common social gesture which often indicates the presence of humor. Detecting laughter and then understanding humor can make machines interact with us in a more natural way. This paper presents an algorithm to automatically detect laughter segments in speech. The voiced laughter of the speaker is recognized and the approximate onsets of the laughter bouts are used to annotate stored conversations. A simple algorithm based on the acoustic properties of voiced laughter is proposed and implemented for the same. The algorithm is able to detect the segments of laughter bouts in data consisting of sentences obtained from the switchboard corpus with an accuracy rate of 77.41% and a false detection rate of 12.90%.
Experimental investigation and optimization of performance, emission, and vibro-acoustic parameters of SI engine fueled with n-propanol and gasoline blends using ANN-GA coupled with NSGA3-modified TOPSIS hybrid approach
(Elsevier Ltd, 2024) Kirankumar, K.R.; Kumar, G.N.; Kamath, N.; Gangadharan, K.V.
In the present study, performance, emission, and vibro-acoustic studies were conducted on a spark ignition (SI) engine fueled with gasoline and an n-propanol blend at variable compression ratio (CR), speed, and propanol blend fraction (PBF). Experimental data were used to model an artificial neural network (ANN) trained with a genetic algorithm (GA). ANN predictive responses were employed to establish regression relationships between brake power (BP), brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), oxides of nitrogen (NOx), carbon monoxide (CO), hydrocarbon (HC), resultant vibration acceleration (RVA), and sound pressure level (SPL) with operating parameters using response surface methodology (RSM). These models served as objective functions in the non-dominated sorting genetic algorithm-3 (NSGA3), a multi-objective optimization (MOO) technique, to optimize responses and obtain non-dominated solutions. These solutions were filtered using a modified technique for order preference by similarity to the ideal solution (TOPSIS) to obtain a compromised optimal solution. ANN-GA model outcomes showed high accuracy, with coefficient of determination (R2) and root mean square error (RMSE) values ranging from 0.979 to 0.993 and 0.0381 to 0.0643, respectively. NSGA3 coupled with modified TOPSIS identified optimal operating conditions at 1271.77 RPM, a CR of 11.96, and a PBF of 33.26 %. © 2024 Elsevier Ltd
Experimental investigation for vibration attenuation for power tools
(American Institute of Physics, 2025) Kamath, N.; Shenoy, P.; Tanappagol, P.S.; Rai, S.K.; Kalluvalappil, G.
Construction zones are often buzzing with "chatter"emanating from different machines. The most commonly used machines are hand-held power tools that handle materials such as bricks, concrete, and other masonry-related materials. The labourers are exposed to vibrations from the device during operation for a prolonged period, causing lasting damage to the hand-arm system. Many factors lead to the unpredictable behaviour of the machine, making it difficult to manoeuvre. Increased gripping forces result in the hand-arm system being a better vibration medium. To counteract this effect, smart materials can stabilise the system. Magnetorheological Elastomers are one such material that can solve the problem of stabilising the device as they can adapt to different conditions, providing semi-active isolation for a wide range of frequencies and demonstrating its force-dependent behaviour. A handle made of MRE can be used to replace the conventional handle at the chuck region. This paper presents how the handle behaves in static conditions under the influence of different magnetic fields for an impact hammer test. Â© 2025 Author(s).
Experimental Modal Analysis Using Impact Hammer Testing with Random Forest-Based Prediction of Magnetorheological Elastomer Dynamics
(Institute of Physics, 2025) Shenoy, P.; Kamath, N.; Pawar, K.; Singh, N.; Soundarya; Afnan, S.; Mayya D, S.
This study presents a novel integration of impact hammer-based experimental modal analysis with Random Forest Regression (RFR) to rapidly characterise the frequency-domain dynamic behaviour of Carbonyl Iron Particle (CIP)-based Magnetorheological Elastomers (MREs) under varying magnetic fields. Using only applied current and excitation frequency as input features, the RFR model predicts FRF amplitude, phase, and coherence with R2 values exceeding 0.96 across both low-frequency (0-70 Hz) and high-frequency (> 70 Hz) regimes. This hybrid experimental-computational framework significantly reduces the number of repeated tests required, enabling faster parametric studies and paving the way for real-time, AI-enhanced tuning of smart vibration isolation systems. Â© Published under licence by IOP Publishing Ltd.
Implementation of model free fuzzy control on a novel magnetorheological elastomer-based handle for a rotary hammer
(Institute of Physics, 2025) Kamath, N.; Shenoy, K.; Susheelkumar, G.N.; Gangadharan, K.V.
This study presents a novel application of a Magnetorheological Elastomer-based handle (MREH) designed to improve the user’s comfort, specifically by reducing hand-arm vibrations. Various control logics were used on the MREH system attached to a rotary hammer to fully utilize the ability to adapt to various operating conditions, and each logic’s performance was evaluated. On/Off, PID, and fuzzy methods have been implemented in real-time. A case-based control logic where the frequency of the rotary hammer is given as an input to the control logic is developed to reduce the decision time as the events occur at a higher rate for on/off and fuzzy. PID gains are obtained directly from the experimental setup through PID autotuning. The performance of these logics is evaluated by performing a drilling operation on a M45 concrete block. Further, the fuzzy logic is investigated by operating at different locations on the same block. Based on the present research, fuzzy logic has demonstrated superior performance in aligning with the system by exhibiting a maximum 3 Hz increase from the natural frequency © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.
Implementing indoor climate control using a cyber-physical systems approach
(American Institute of Physics, 2025) Verma, B.S.; Kamath, N.; Bidari, L.; Kalluvalappil, G.
Maintaining a comfortable temperature, reducing humidity, and optimizing airflow constitute indoor climate control. This improves the air quality by controlling moisture and regulating the air. Climate-sensitive situations, like those in Intensive Care Units (ICU) and laboratories that follow Bio-safety levels (BSL), heavily depend on this technology to ensure health and safety by keeping the environment sterile by manipulating the airflow. The extent of this technology is more comprehensive than these situations. This solution can benefit people living in harsh conditions where comfort and productivity are seldom limited. This study proposes a novel cyber-physical system (CPS) approach by considering individual parameters influencing indoor climate, such as temperature, humidity, and occupancy. A distributed approach where multiple custom-made units that house a microcontroller and sensors such as DHT-11, DHT-22, ENS160, and PIR motion sensor are kept in strategic locations that communicate with each other over Things board, and the air conditioning unit present in the enclosed space ensures optimal indoor climate control. Considering the occupancy data, the system adjusts itself in real time, optimizing energy consumption and leading to localized climate regulation. This study explores the application of control logic in a small-scale Peltier device system. The objective is to develop a control system that efficiently regulates the Peltier device's temperature. This study investigates control strategies, i.e., Proportional-Integral-Derivative (PID) control, to maintain precise temperature control in the system. The control method is analyzed for its effectiveness, robustness, and energy efficiency in the context of the Peltier device. A 3Â°C reduction was observed for 3 minutes in the scaled system. Â© 2025 Author(s).
Investigation of Field Dependent Variations of Torsional Stiffness of Magnetorheological Elastomer
(American Institute of Physics, 2024) Kaup, P.S.; Kumar, S.; Kamath, N.; Mayya, S.; Gangadharan, K.V.
Isolation of torsional vibrations in shafts is one of the most important aspects of a sound design system. Though existing systems such as the centrifugal pendulum absorber and the flywheels reduce the effects to a certain extent, the system fails to comply when the natural frequency of the torsional system changes. To counteract such instances, smart materials are used to tune their parameters based on the variations in the system variables. Magnetorheological Elastomers offer a viable solution to the dynamic vibrations as they can adhere to variations in system properties. To properly implement the MRE, it is mandatory to characterize the mechanical properties under dynamic loading conditions under varying magnetic fields. The present paper focuses on characterizing the torsional stiffness of the MRE under varying magnetic fields. The characterization methodology is discussed with the building of the measurement system, followed by the results and discussions of varying hysteresis loops for different magnetic fields. Variations in the properties are discussed, highlighting the role of the dipole mechanism. Â© 2024 American Institute of Physics Inc.. All rights reserved.
Semi-Active Vibration Isolation of a Modular Magnetorheological Elastomer Device with ON-OFF and Fuzzy Logic Control
(Institute of Physics, 2025) Sathiyasai, S.; Kamath, N.; Shenoy, K.P.; Vinod, N.; Rao, G.; Gangadharan, G.
A modular device incorporating a magnetorheological elastomer (MRE) has been developed for vibration isolation applications. Following characterisation of its open-loop dynamic behaviour, this study investigates semi-active control strategies - ON/OFF control, proportional-integral-derivative (PID) control, and fuzzy logic control - targeting vibration attenuation at a dominant frequency of 12 Hz. These controllers dynamically adjust the MRE's damping properties by modulating the electromagnet's magnetic field in response to input vibration signals. Performance was evaluated using a shaker setup with a defined vibration spectrum, with the electromagnet's power consumption serving as a key metric. Experimental results show that ON/OFF control consumed the highest energy, drawing an average current of 2.5 A (26 W) and using 130 J over 5 s. While fuzzy logic control achieved the lowest consumption, a 72.5 % reduction compared to ON/OFF and 37.2 % less than PID. These findings highlight fuzzy logic control as the most energy-efficient strategy, offering significant power savings without compromising vibration isolation performance. Â© Published under licence by IOP Publishing Ltd.
Tensile behavior of lightweight foam filament
(2019) Kamath, N.; Anawal, R.; Doddamani, M.
Filaments of high-Density Polyethylene (HDPE) with Glass Microballoons (GMBs) by20, 40 and 60 volume% are developed and studied for tensile characterization. Density of syntactic foam filaments are lower compared to pure HDPE filaments. The syntactic foam filament developed results in weight saving potential of 28% owing to inclusion of hollow GMBs in matrix resin making them suitable for marine applications. Modulus of syntactic foam filaments increases with increasing GMB volume % compared to neat HDPE. Tensile strength of syntactic foams filaments is lower as compared to pure HDPE filament. These developed lightweight filaments can be used for 3D printing of complex geometries. � 2019 IOP Publishing Ltd. All rights reserved.
Tensile behavior of lightweight foam filament
(Institute of Physics Publishing helen.craven@iop.org, 2019) Kamath, N.; Anawal, R.; Doddamani, M.
Filaments of high-Density Polyethylene (HDPE) with Glass Microballoons (GMBs) by20, 40 and 60 volume% are developed and studied for tensile characterization. Density of syntactic foam filaments are lower compared to pure HDPE filaments. The syntactic foam filament developed results in weight saving potential of 28% owing to inclusion of hollow GMBs in matrix resin making them suitable for marine applications. Modulus of syntactic foam filaments increases with increasing GMB volume % compared to neat HDPE. Tensile strength of syntactic foams filaments is lower as compared to pure HDPE filament. These developed lightweight filaments can be used for 3D printing of complex geometries. Â© 2019 IOP Publishing Ltd. All rights reserved.
Tunable Vibration Control in Power Tool Handles Using a Magnetorheological Elastomer Device
(Institute of Physics, 2025) Sathiyasai, S.; Kamath, N.; Shenoy, K.P.; Rai, S.K.; Tanappagol, P.S.; Rajesh; Gangadharan, G.
A novel modular device integrating a magnetorheological elastomer (MRE) has been designed for adaptable attachment to various power tool auxiliary handles using their standard circular clamp and T-headed bolt mechanism. The core of the electromagnet of the device serves as the primary attachment interface. A relative validation approach was adopted to characterize its vibration control capabilities across different tool configurations. Instead of device-specific testing, the modular unit, loaded with supplementary masses of 1 kg and 1.5 kg to simulate various power tool weights, was mounted on a shaker and exposed to a defined vibration spectrum. The effect of varying the magnetic field strength on the dynamic behavior of the MRE-based isolator was examined. Experimental results reveal a notable positive shift in the system's natural frequency of approximately 3 Hz, transitioning from 12 Hz to 15 Hz when the maximum magnetic field was applied. Concurrently, the transmitted vibration amplitude was substantially reduced, averaging around 12%, under the same maximum field conditions. These findings highlight the potential of this modular MRE device as a versatile and easily integrable solution for tunable vibration damping in a wide array of power tools. Its semi-active nature offers a pathway to significantly enhance user comfort, reduce operator fatigue, and improve overall operational stability across diverse applications. Â© Published under licence by IOP Publishing Ltd.
Visible light-induced photocatalytic degradation of Reactive Blue-19 over highly efficient polyaniline-TiO2 nanocomposite: a comparative study with solar and UV photocatalysis
(Springer Verlag service@springer.de, 2018) Kalikeri, S.; Kamath, N.; Gadgil, D.J.; Shetty K, V.
Polyaniline-TiO2 (PANI-TiO2) nanocomposite was prepared by in situ polymerisation method. X-ray diffractogram (XRD) showed the formation of PANI-TiO2 nanocomposite with the average crystallite size of 46 nm containing anatase TiO2. The PANI-TiO2 nanocomposite consisted of short-chained fibrous structure of PANI with spherical TiO2 nanoparticles dispersed at the tips and edge of the fibres. The average hydrodynamic diameter of the nanocomposite was 99.5 nm. The band gap energy was 2.1 eV which showed its ability to absorb light in the visible range. The nanocomposite exhibited better visible light-mediated photocatalytic activity than TiO2 (Degussa P25) in terms of degradation of Reactive Blue (RB-19) dye. The photocatalysis was favoured under initial acidic pH, and complete degradation of 50 mg/L dye could be achieved at optimum catalyst loading of 1 g/L. The kinetics of degradation followed the Langmuir-Hinshelhood model. PANI-TiO2 nanocomposite showed almost similar photocatalytic activity under UV and visible light as well as in the solar light which comprises of radiation in both UV and visible light range. Chemical oxygen demand removal of 86% could also be achieved under visible light, confirming that simultaneous mineralization of the dye occurred during photocatalysis. PANI-TiO2 nanocomposites are promising photocatalysts for the treatment of industrial wastewater containing RB-19 dye. © 2017, Springer-Verlag GmbH Germany, part of Springer Nature.