Aasifa Rounak

About Aasifa Rounak

Aasifa Rounak, With an exceptional h-index of 4 and a recent h-index of 4 (since 2020), a distinguished researcher at Indian Institute of Technology Madras, specializes in the field of Nonlinear dynamics, Non-smooth dynamics, Chaos, Mechanics, Random Vibrations.

His recent articles reflect a diverse array of research interests and contributions to the field:

Detection of Pipeline Leaks using BiopiezoelectricEnergy Harvesting Sensors via RecurrenceQuantification and Neuromorphic Computing

Wake-induced response of vibro-impacting systems

ENERGY HARVESTING–NEW GREEN ENERGY

Stability analysis of hybrid systems with higher order transverse discontinuity mapping

Characterising stochastic fixed points and limit cycles for dynamical systems with additive noise

Bifurcations in a pre-stressed, harmonically excited, vibro-impact oscillator at subharmonic resonances

Stochastic P-bifurcation in a nonlinear impact oscillator with soft barrier under Ornstein–Uhlenbeck process

Aasifa Rounak Information

University

Indian Institute of Technology Madras

Position

MS Ph. D Research Scholar

Citations(all)

34

Citations(since 2020)

34

Cited By

5

hIndex(all)

4

hIndex(since 2020)

4

i10Index(all)

1

i10Index(since 2020)

1

Email

University Profile Page

Indian Institute of Technology Madras

Aasifa Rounak Skills & Research Interests

Nonlinear dynamics

Non-smooth dynamics

Chaos

Mechanics

Random Vibrations

Top articles of Aasifa Rounak

Detection of Pipeline Leaks using BiopiezoelectricEnergy Harvesting Sensors via RecurrenceQuantification and Neuromorphic Computing

Authors

Aasifa Rounak,Shreyan Banerjee,George Vathakkattil Joseph,Favour Okosun,Sarah Guerin,Vikram Pakrashi

Published Date

2024/3/5

This paper presents a study on water pipeline leak detection using organic glycineenergy harvesting sensors. The analysis involves examining open circuit voltageswith recurrence quantification analysis (RQA), complexity measures, and neuromorphiccomputing techniques. Time-dependent un-thresholded recurrence plotsreveal nonlinear characteristics in bio-piezoelectric sensed signatures, providinginsights into leak intensities, flow rates, and sensor locations over short and longtime scales. RQA measures successfully distinguish between leak states, withincreased flow rates resulting in notable changes. The results indicate that glycinesensors outperform PVDF sensors in accurate leak detection. The methodologyis adapted to a neuromorphic framework, estimating leak occurrence and sizeclassification. The spiking neural network-based model shows the superiority ofbio-piezoelectric sensors for structural health monitoring within a neuromorphicframework, compared to PVDF sensors.

Wake-induced response of vibro-impacting systems

Authors

Rohit Chawla,Aasifa Rounak,Chandan Bose,Vikram Pakrashi

Journal

arXiv preprint arXiv:2305.04284

Published Date

2023/5/7

This study investigates the bifurcation behaviour of wake-induced vibro-impacting systems considering fluid-structure interaction (FSI). The primary structure and the near wake dynamics are modelled as a harmonic oscillator a Van der Pol oscillator, respectively, and are weakly coupled to each other. A non-deformable barrier obstructing the motion of the oscillator gives rise to the impacting dynamics. Instantaneous velocity reversal occurs when the structure impacts with this barrier. Qualitative changes in the dynamical behaviour of this system are investigated in the context of discontinuity-induced bifurcations (DIBs) resulting from the interaction of fluid flow and non-smoothness from the primary structure. Phenomenological behaviour like co-existence of attractors and period-adding cascades of limit cycles leading to chaos are examined. Existence of these phenomena are demonstrated via stability analysis using Floquet theory and associated Lyapunov spectra. A new approach to capture the impact dynamics of the hybrid system through a transverse discontinuity map is proposed. Orbits obtained using this new algorithm is demonstrated to accurately predict both stable and chaotic regimes as observed from the corresponding bifurcation diagrams. The effect of the presence of non-smoothness on the lock-in phenomenon in systems that involve fluid-structure interaction is studied for the first time

ENERGY HARVESTING–NEW GREEN ENERGY

Authors

Bartłomiej Ambrożkiewicz,Aasifa Rounak

Journal

Journal of Technology and Exploitation in Mechanical Engineering

Published Date

2022/11/4

Energy Harvesting is the process in which energy is captured from a system's environment and converted into usable electric power. Energy harvesting allows electronics to operate where there's no conventional power source, eliminating the need to run wires or make frequent visits to replace batteries, that makes it the new possibility of green energy source. This short letter reports the 3 new designed energy harvesting systems based on the electromagnetic and piezoelectric effect from two universities, ie Lublin University of Technology (Poland) and University College Dublin (Republic of Ireland). The proposed systems can be used as a power supply for low-energy devices or in the diagnostics.

Stability analysis of hybrid systems with higher order transverse discontinuity mapping

Authors

Rohit Chawla,Aasifa Rounak,Vikram Pakrashi

Journal

arXiv preprint arXiv:2203.13222

Published Date

2022/3/24

This article generalizes the implementation of higher order corrections to state transition matrices during instantaneous reversals in hybrid dynamical systems impacting a discontinuity boundary transversally. A closed form expression for saltation terms in systems possessing a degree of smoothness zero is derived. The difference in flight times of two closely initiated trajectories in state space to the impacting surface has been estimated up to . A comparison of the times of impact estimated with the first order approximation reveals that higher order corrections lead to a significant improvement of estimates. Next, two new algorithms to estimate the Lyapunov spectrum and Floquet multipliers for piecewise-smooth systems have been presented using the derived second order corrections. Stability analyses are subsequently carried out using the proposed framework for two representative cases {\it i.e.,} of a hard impact oscillator and a pair impact oscillator. It is established that the obtained Floquet multipliers and Lyapunov spectrum accurately predict the stability of the dynamical states, as validated by their corresponding bifurcation diagrams.

Characterising stochastic fixed points and limit cycles for dynamical systems with additive noise

Authors

Saranya Biswas,Aasifa Rounak,Przemysław Perlikowski,Sayan Gupta

Journal

Communications in Nonlinear Science and Numerical Simulation

Published Date

2021/10/1

This study focuses on characterising numerically the attractor volume in the state space of dynamical systems excited by additive white noise. A definition for stochastic attractors is introduced in terms of probability measure and numerical methodologies are presented to characterise them. The study is limited to investigating the effects of additive noise on fixed point and limit cycle attractors of the corresponding noise free system. The effect of noise intensity on the definition and validity of the proposed methodology is also discussed.

Bifurcations in a pre-stressed, harmonically excited, vibro-impact oscillator at subharmonic resonances

Authors

Aasifa Rounak,Sayan Gupta

Journal

International Journal of Bifurcation and Chaos

Published Date

2020/6/30

This study investigates the behavior of a damped, inelastic, sinusoidally forced impact oscillator which has its barrier placed such that the oscillator always vibrates under compression about its subharmonic resonant frequencies. The Poincaré sections at near subharmonic resonance conditions exhibit finger-shaped chaotic attractors, similar to the strange attractor mapping of Hénon and the ones found by Holmes in his study of chaotic resonances of a buckled beam. The number of such fingers are observed to increase as the barrier distance from the equilibrium is decreased. These chaotic states are interspersed with regimes of periodic behavior, with the periodicity being in accordance with well defined period adding laws. This study also focuses on the ordered behavior of the one-impact period- orbits around the higher subharmonics of the oscillator.

Stochastic P-bifurcation in a nonlinear impact oscillator with soft barrier under Ornstein–Uhlenbeck process

Authors

Aasifa Rounak,Sayan Gupta

Journal

Nonlinear Dynamics

Published Date

2020/3

This study investigates the effect of randomness in the forcing on a harmonically excited bilinear impact oscillator with a soft barrier. The system parameter range considered coincides with regimes in which multiple stable attractors coexist. The random component superimposed on the harmonic excitations is shown to lead to qualitatively different dynamical behaviours at different parameter values, due to the presence of multiple coexisting attractors. This is classified as P-bifurcation. Wavelet analysis and recurrence quantification-based tools have been employed to show that these qualitative changes are due to noise-induced intermittency in the system.

See List of Professors in Aasifa Rounak University(Indian Institute of Technology Madras)

Aasifa Rounak FAQs

What is Aasifa Rounak's h-index at Indian Institute of Technology Madras?

The h-index of Aasifa Rounak has been 4 since 2020 and 4 in total.

What are Aasifa Rounak's top articles?

The articles with the titles of

Detection of Pipeline Leaks using BiopiezoelectricEnergy Harvesting Sensors via RecurrenceQuantification and Neuromorphic Computing

Wake-induced response of vibro-impacting systems

ENERGY HARVESTING–NEW GREEN ENERGY

Stability analysis of hybrid systems with higher order transverse discontinuity mapping

Characterising stochastic fixed points and limit cycles for dynamical systems with additive noise

Bifurcations in a pre-stressed, harmonically excited, vibro-impact oscillator at subharmonic resonances

Stochastic P-bifurcation in a nonlinear impact oscillator with soft barrier under Ornstein–Uhlenbeck process

are the top articles of Aasifa Rounak at Indian Institute of Technology Madras.

What are Aasifa Rounak's research interests?

The research interests of Aasifa Rounak are: Nonlinear dynamics, Non-smooth dynamics, Chaos, Mechanics, Random Vibrations

What is Aasifa Rounak's total number of citations?

Aasifa Rounak has 34 citations in total.

What are the co-authors of Aasifa Rounak?

The co-authors of Aasifa Rounak are Vikram Pakrashi, Przemysław Perlikowski, Sayan Gupta.

    Co-Authors

    H-index: 37
    Vikram Pakrashi

    Vikram Pakrashi

    University College Dublin

    H-index: 31
    Przemysław Perlikowski

    Przemysław Perlikowski

    Politechnika Lódzka

    H-index: 25
    Sayan Gupta

    Sayan Gupta

    Indian Institute of Technology Madras

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