Balamurali Ramakrishnan

• Doctor of Philosophy
• Professor (Associate) at Chennai Institute Of Technology

The investigation in this paper is founded on the theoretical study of a neuronal circuit driven by a Josephson junction (JJ) under the effects of light and temperature, and its microcontroller design. The neuronal circuit is made of a resistor in series to a phototube (PT) to which an excitation which is a direct current (DC) source, a thermistor,...

Network dynamics is the subject of a great deal of scientific research these days. Its scope is not only restricted to the study of the collective dynamic behavior of the internal subunits of a network or the interaction of connected systems with their neighbors, but it is also applicable to some of today's cutting-edge technologies, and helps us t...

An autonomous chaotic snap system with only one equilibrium point is proposed and analyzed in this paper. Periodic oscillations, self-excited chaotic attractors, hidden chaotic attractors and coexistence of a stable equilibrium point with a hidden chaotic attractor are found during the numerical simulations of the autonomous snap system with hidden...

To examine the hemostatic behaviors of neural activity and extracellular matrix (ECM) molecules, this paper provides a mathematical model for ECM combined with a FitzHugh–Nagumo neuronal model. The dynamic behaviors of the proposed model are investigated utilizing dynamical tools such as Lyapunov exponents and bifurcation diagrams. The basin attrac...

The main objective of this study is to investigate the synchronization of nonautonomous dynamical systems. Specifically, we aim to examine how externally driven forces, in terms of their amplitude and frequency, impact this synchronization phenomenon. To achieve this, we consider two popular neuron models, namely Hindmarsh Rose neuron model and Mor...

The major interest of this article is to investigate a single and an array of mechanical arms driven by Josephson junction (JJ) circuits and their applications in mimicking the locomotion of myriapods. Stability analysis of a single mechanical arm driven by a JJ circuit resulted in two equilibrium points and a switch of their stability for specific...

This work studies the dynamics of a three dimensional Hopfield neural network focusing on the impact of bias terms. In the presence of bias terms, the models displays an odd symmetry and experiences typical behaviors including period doubling, spontaneous symmetry breaking, merging crisis, bursting oscillation, coexisting attractors and coexisting...

This paper reports on the theoretical analysis and microcontroller implementation of smooth nonlinear resistor-capacitor shunted Josephson junction (SNRCSJJ) circuit. The smooth nonlinear resistor is described by a cosine interference term. The stability of the equilibrium points obtained from the rate equations describing the SNRCSJJ circuit revea...

It is known that the unidirectional coupling between a double-scroll system (drive) in the oscillation regime with another system (response) in the steady-state, gives rise to more complex dynamics such as multiscroll attractors [Dana et al., 2008]. This paper shows the way to move from n-scroll to 2n-scroll in a bidirectional coupling scheme betwe...

The paper is aimed at mimicking the motion of myriapods by using an array of mechanical arms coupled to an array of FitzHugh–Nagumo (FN) neuron circuits. The differential equation depicting the electromechanical system is achieved by using Kirchhoff’s and Newton’s laws. The system parameters are sensitive to the stability of the system as shown by...

Artificial neural networks are generally used to emulate some biological activities of the brain. Those neurons in the network are connected to others through synapses. As a result, several works have been devoted to the design of various artificial synapses, including the Josephson Junction Synapse (JJS). In this contribution, a model of the Hindm...

Synchronization in coupled oscillators is of high importance in secure communication and information processing. Due to this reason, a significant number of studies have been performed to investigate the synchronization state in coupled circuits. Diffusive coupling is the simplest connection between the oscillators, which can be implemented through...

A Josephson junction (JJ) based on high critical-temperature superconductors described by a linear resistive–capacitive–inductance shunted junction (LRCLSJ) model with unharmonic current-phase relation (UCPR) is theoretically and experimentally investigated in this paper. The numerical simulations indicate that JJ based on high critical-temperature...

Megastability and coexisting attractors between periodic and self-excited chaotic attractors in the Josephson junction snap oscillator (JJSO) are reported in this paper. Two different cases are considered for this study. In one case, the JJSO is driven by a direct current (DC) whereas in the other case, it is driven by an alternative current (AC)....

This paper reports on the dynamical analysis, field programmable gate array (FPGA) implementation of autonomous Josephson junction (JJ) jerk oscillator with cosine interference term (AJJJOCIT) and investigation of its collective behavior in a network. The AJJJOCIT derived from a resistive capacitive shunted JJ model with cosine interference term ha...

Multistability and symmetry breaking have been significantly investigated recently. In this paper, we study the effects of symmetry breaking on the behavior of a particular class of inertial neural systems with a non-monotonic activation function. By introducing a constant term in the nonlinearity of the model, we show that this system presents asy...

A megastable oscillator with various types of attractors is proposed. The oscillator shows interesting dynamics like cloud, kite, and arrow-like attractors. As we know, such a megastable oscillator with the dynamic shapes was not previously reported. There is an infinite number of arrow-like attractors in this oscillator. Investigating equilibrium...

A linear resistive capacitive inductive shunted model of a Josephson junction with a topologically nontrivial behavior is considered in this paper. We have considered a fractional order flux controlled memristor to effectively model the feedback flux effects across the Josephson junction (JJ). The mathematical model of the proposed JJ oscillator is...

To understand the variations in the financial characteristics, we examine the dynamical behaviors by considering the chaotic financial model with external force. First, the dynamical characteristics are analyzed by introducing the external driven force in the price index with commodity demand. We discover that the presence of an external force caus...

This paper reports on the theoretical analysis and microcontroller implementation of smooth nonlinear resistor-capacitor shunted Josephson junction (SNRCSJJ) circuit. The smooth nonlinear resistor is described by a cosine interference term. The stability of the equilibrium points obtained from the rate equations describing the SNRCSJJ circuit revea...

The dynamical analysis, field programmable gate array (FPGA) implementation and image encryption of a linear piecewiseresistive-capacitive-inductive shunted Josephson junction (LPRCISJJ) model are reported in this paper. The numerical simulations of LPRCISJJ model reveal the existence of periodic attractors, bistable periodic attractors, antimonoto...

It is known that hyperchaotic signals are suited for designing chaos-based secure communication systems. Based on a first-order generalized diodes bridge memristor emulator, the dynamical behavior of a higher order autonomous Van der Pol-Duffing oscillator is investigated in this article. This oscillator is able to exhibit some complex and interest...

The simplest megastable chaotic system is built by employing a piecewise-linear damping function which is periodic over the spatial domain. The unforced oscillator generates an infinite number of nested limit cycles with constant distances whose strength of attraction decreases gradually as moving to outer ones. The attractors and the basins of att...

A circuit made of a phototube in series with a linear resistor connected in parallel to a resistor-capacitor shunted Josephson junction (JJ) is proposed to describe a neuron sensitive to external illuminations. The neuronal circuit based on JJ actuated by a photocurrent is analytically, numerically and experimentally investigated in this paper. The...

This paper discusses the theoretical analysis and microcontroller implementation of resistive–capacitive shunted Josephson junction (JJ) with unharmonic current-phase relation. The rate equations describing the system under study exhibit no, two, or four equilibrium points and their stability are investigated.The presence of Pitchfork bifurcation d...

A unique mega-stable oscillator with a memristor device is constructed, with the special properties of parity invariant, approximate symmetry, and attractor growing. The introduced memristor device with sinusoidal functions holds the polarity when each variable switches from positive to negative, and correspondingly approximate symmetric coexisting...

The dynamical analysis, field programmable gate array (FPGA) implementation and image encryption of a linear piecewiseresistive-capacitive-inductive shunted Josephson junction (LPRCISJJ) model are reported in this paper. The numerical simulations of LPRCISJJ model reveal the existence of periodic attractors, bistable periodic attractors, antimonoto...

Fractional-order neuronal models that include memory effects can describe the rich dynamics of the firing of the neurons. This paper studies synchronization problems in a multiple network of Caputo–Fabrizio type fractional order neurons in which the orders of the derivatives in the layers are different. It is observed that the intralayer synchroniz...

Dynamical analysis, chaos suppression and electronic implementation of the synchronous reluctance motor (SynRM) without external inputs are investigated in this paper. The different dynamical behaviors (including monostable periodic behaviors, bistable periodic behaviors, monostable chaotic behaviors, and bistable chaotic behaviors) found in the Sy...

Dynamics of multi-layered neuronal network are challenging and spiral wave suppression is vital particularly in biological systems such as cortical tissue in brain, heart muscles etc., In this study, one-, two- and three-layer neuronal network of an exponential flux memristor-based Morris-Lecar neuron model subjected to low-frequency electromagneti...

Brain functions are sometimes emulated using some analog integrated circuits based on the organizational principle of natural neural networks. Neuromorphic engineering is the research branch devoted to the study and realization of such circuits with striking features. In this contribution, a novel small network of three neurons is introduced and in...

In this paper, we propose a new and simple method for image encryption. It uses an external secret key of 128 bits long and an internal secret key. The novelties of the proposed encryption process are the methods used to extract an internal key to apply the zigzag process, affine transformation, and substitution-diffusion process. Initially, an ori...

A memristor is a vital circuit element that can mimic biological synapses. This paper proposes the memristive version of a recently proposed map neuron model based on the phase space. The dynamic of the memristive map model is investigated by using bifurcation and Lyapunov exponents’ diagrams. The results prove that the memristive map can present d...

In this article, a new model of Hopfield Neural Network (HNN) with two neurons considering a synaptic weight with a hyperbolic-type memristor is studied. Equilibrium points analysis shows that the system has an unstable line of equilibrium in the absence of the external stimuli (i.e. \(I_{1} =0)\) and presents no equilibrium point in the presence o...

Designing novel mega-stable chaotic oscillators has been a hot topic of research lately. In the current paper, a two-dimensional mega-stable oscillator is presented. The oscillator has a vast amount of coexisting limit cycles that spread on a surface. The forced version of this system is a novel nonlinear oscillator with an immense number of coexis...

This paper addresses the effects of offset terms on the dynamics of a modified Chua’s oscillator. The mathematical model is derived using Kirchhoff’s laws. The model is analyzed with the help of the maximal Lyapunov exponent, bifurcation diagrams, phase portraits, and basins of attraction. The investigations show that the offset terms break the sym...

In this paper, bidirectional-coupled neurons through an asymmetric electrical synapse are investigated. These coupled neurons involve 2D Hindmarsh–Rose (HR) and 2D FitzHugh–Nagumo (FN) neurons. The equilibria of the coupled neurons model are investigated, and their stabilities have revealed that, for some values of the electrical synaptic weight, t...

This paper studies the effect of the electromagnetic flux on the dynamics of an introduced model of heterogeneous coupled neurons. Analytical investigation of the coupled neurons revealed that the obtained model is equilibrium free thus displays hidden firing activities. Based on the Helmholtz theorem, it is demonstrated that the coupled neurons po...

The dynamical features and the digital implementation of a microcontroller Josephson junction neuron model driven by a thermal signal is investigated in this paper. By designing the system above as a thermistor in series to some variant voltage source connected in parallel to a resistor and a capacitor, we show that the hysteresis loop appearances...

ZnS-Co3S4 Nanoscrubbers were prepared by hydrothermal routes and characterized by advanced techniques. The supercapacitance behavior of crystalline ZnS-Co3S4 nanoscrubber modified electrodes was examined using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques. As-prepared ZnS-Co3S4 nanoscrubbers have a high specific capaci...

A fractional-order difference equation model of a third-order discrete phase-locked loop (FODPLL) is discussed and the dynamical behavior of the model is demonstrated using bifurcation plots and a basin of attraction. We show a narrow region of loop gain where the FODPLL exhibits quasi-periodic oscillations, which were not identified in the integer...

The analysis and field programmable gate arrays (FPGA) implementation of a resistive-capacitive-inductive shunted Josephson junction (RCLSJJ) circuit with topologically nontrivial barrier (TNB) are investigated in this paper. The stability analysis of the equilibrium points reveals the presence of a Pitchfork bifurcation. RCLSJJ circuit with TNB ca...

The controls of chaotic and coexisting attractors and collective dynamics in linear resistive-capacitive-inductive shunted Josephson junction (LRCISJJ) model are investigated in this paper. A single feedback controller is designed to control chaos found in the LRCISJJ model. Analytical calculations and numerical simulations are carried out to show...

In this article, a single nonautonomous Hopfield neuron is investigated. This neuron involves a new hyperbolic-type memristor as self-synaptic weight. The current-voltage characteristics of the new memristor enables the observation of the pinched hysteresis loop at three points. The analysis of the equilibria highlighted that the model has hidden d...

Nowadays, many prevalent frameworks for medical care have been projected, studied, and implemented. The load and challenges of traditional hospitals are increasing daily, leading to inefficient service in the health system. Smart hospitals based on advanced techniques play a crucial part in advancing the health services of rural people. It spares t...

We consider the dynamics of a system of two coupled van der Pol oscillators whose (inversion) symmetry is broken by a constant excitation force. We investigate the bifurcation structures of the system both with respect to its parameters and the intensity of the excitation force as well using numerical methods. It is found that the forced system exp...

A Morris–Lecar neuron model is considered with electric and magnetic field effects where the electric field is a time-varying sinusoid and magnetic field is simulated using an exponential flux memristor. We have shown that the exposure to electric and magnetic fields have significant effects on the neurons and has exhibited complex oscillations. Th...

In recent times, air pollution has attracted the attention of policymakers and researchers as an important issue. The pollution that contaminates the air that people breathe is from pollutants such as oxides of carbon, nitrogen and sulphur as well minuscule dust particle which are smaller than 0.0025mm in diameter. The emissions contain many substa...

In this paper, we investigate the wave propagation phenomenon and network dynamics of an improved Hindmarsh–Rose neuron model considered with magnetic induction. The dynamical properties of the improved neuron model in discussed with the help of eigenvalues, Lyapunov exponents and bifurcation plots. A simple comparison between the exponential flux...

A Morris-Lecar neuron model is considered with Electric and Magnetic field effects where the electric field is a time varying sinusoid and magnetic field is simulated using an exponential flux memristor. We have shown that the exposure to electric and magnetic fields have significant effects on the neurons and have exhibited complex oscillations. T...

Josephson junction devices play a significant role in various physical nonlinear systems because of their complex characteristics. Chaotic phenomenon in various types of Josephson junction devices has been widely reported, but many of those literature studies exempted the analysis into multistability and megastability features of the device. In thi...

This paper proposes the fault detection filter for wireless sensor network. The problem of time-varying nonlinear filter is causing randomly varying nonlinearity due to environment, quantization error and packet dropout are solved by combining Bernoulli distributed white sequence and Robotics based Type-2 T–S (Takagi–Sugeno) Fuzzy method by taking...

A multilevel H-bridge dc–ac converter is an electronic device, the multilevel converter enhanced stepped output with less switches. This paper deals with H-Bridge multilevel converter it requires only few switches when compared to traditional method. So in proposed method using only few switches, and it requires less gate triggering circuit. Less s...

Information on rainfall prediction has great significance in agricultural fields where most of the crop’s irrigation depends on the rain water. Thus, rainfall prediction is a mandatory and an important process recently. Classical logic is further extended into fuzzy logic. Fuzzy logic has many advantages over classical logic. Two types of connotati...

Memristors play a vital role in the design of high density and low power memory devices. Considering the complex behaviour of memristor devices because of the feature that its memductance changes with the input current, these devices finds its applications in design of nonlinear circuits. Similarly, Josephson junction resonators also exhibit comple...

Objective: Cardiovascular disease is one among the major mortality threats throughout the world. Autonomic activity of the nervous system can be examined by heart rate variability (HRV) analysis. Association of sympathetic and parasympathetic activities is directly related to HRV modulation. The aim of the study is to determine variations in HRV pa...

The United Nations Environment Conference in Rio de Janeiro impelled the idea of sustainable development into the view of public awareness. Sustainability refers to usage of resources efficiently and saving the resources for the future generations, this can be done only by the collective work for both individual and organization. Engineers plays a...

Multi-parameter algorithm with statistical approach for adult image discretion is proposed to figure out the obscene images. In this work, we propose an analysis on different color spaces to identify an effective pixel identification for human skin. In this work, an algorithm is incorporated to verify and spirit away the unambiguous image by identi...

In this paper, the FPGA Implementation of complete synchronization methodology for non-identical hyperchaotic systems using active control theory is proposed. In proposed methodology, FPGA technology is used for the synchronization of Simplified Lorentz hyperchaotic system and Pang hyperchaotic system, Xilinx system generator technology was used fo...

A novel two stage multiple parameter statistical algorithm to identify pornographic images is proposed in this study. In the current study we present an analysis on various color spaces to identify an optimal color space for human skin pixel identification. A new algorithm is proposed to identify and avoid the explicit image by considering high ski...