Noether symmetry theorem of Herglotz type for time-delayed fractional Birkhoffian system are studied. Firstly, based on the fractional derivative of Riemann-Liouville, the Herglotz variational principle of time-delayed fractional Birkhoffian system is established, and the time-delayed Birkhoff′s equation of Herglotz type is derived. Secondly, the definition and criterion of Herglotz type Noether symmetric

COVID-19 is an emerging and rapidly evolving pandemic around the world, which causes severe acute respiratory syndrome and results in substantial morbidity and mortality. To examine the transmission dynamics of COVID-19, we investigate the spread of this pandemic using Malaysia as a case study and investigate its interactions with some exogenous factors such as limited medical resources and false detection

The proposed work utilizes Support Vector Regression model to predict the number of total number of deaths, recovered cases, cumulative number of confirmed cases and number of daily cases. The data is collected for the time period of 1st March,2020 to 30th April,2020 (61 Days). The total number of cases as on 30th April is found to be 35043 confirmed cases with 1147 total deaths and 8889 recovered

In spite of its simple formulation via a nonlinear differential equation, the Gompertz model has been widely applied to describe the dynamics of biological and biophysical parts of complex systems (growth of living organisms, number of bacteria, volume of infected cells, etc.). Its parameters or coefficients and the initial condition represent biological quantities (usually, rates and number of individual/particles

In this paper, the phenomena of coherence resonance (CR) and stochastic resonance (SR) are studied in an asymmetric tri-stable potential with memory effects, which is driven by internal noise and a periodic forcing. Analytical expressions for characteristic correlation time and spectral amplification are derived to quantify the CR and the SR, respectively. The obtained results indicate the existence

A new cellular automata traffic model based on the revised S-NFS model was established to consider a mixed flow of automated and human-driven vehicles assuming a multi-lane system. The model further classified automated vehicles into two categories: (1) vehicles with adaptive cruise control and (2) those with cooperative adaptive cruise control that supports so-called platoon driving. A vehicle that

Chaos is a paradigm shift of all science, which provides a collection of concepts and methods to analyze a novel behavior that can arise in a wide range of disciplines. However, most of researches in simulations and applications of chaos are performed on finite-state automata, which inevitably causes chaos to collapse. Here we present a hybrid model by controlling digital system with continuous chaotic

The aim of this work is to study local changes of fractality in mouse embryonic lens. Embryos were removed from female mice that have been subjected to a diet deficient in folic acid for two and eight weeks. The local change of fractality is studied through the analysis of the Local Connected Fractal Dimension (LCFD) on binarised images of these lenses using FracLac plugin for ImageJ, after immunohistochemical

Cholera is an acute, diarrheal infection of the intestine which spreads by the ingestion of contaminated water or food. It is an important health problem, especially in counties with poor sanitation and hygiene. In this paper, the Cholera dynamics model with continuous controls is theoretically investigated using optimal control theory. First, the parameters of the assumed model are estimated using

COVID-19 declared as a global pandemic by WHO, has emerged as the most aggressive disease, impacting more than 90% countries of the world. The virus started from a single human being in China, is now increasing globally at a rate of 3% to 5% daily and has become a never ending process. Some studies even predict that the virus will stay with us forever. India being the second most populous country of

Optimal communication waveforms matched to a large and practically important class of filters are investigated and shown to be chaotic. Filters of this class are defined by an infinite impulse response (IIR) and a transfer function comprising a finite number of distinct stable poles. This class contains many of the most popular and widely used filter families, including Butterworth, Chebyshev (type

In this paper, some mathematical support is provided to properly justify the validity of the so-called multifractal height cross-correlation analysis (MFHXA), first contributed by Kristoufek (2011)[1]. With this aim, we extend several concepts from univariate random functions and their increments to the bivariate case. Specifically, we introduce the bivariate cumulative range as well as the concepts

This work presents the modeling and prediction of cases of COVID-19 infection in Mexico through mathematical and computational models using only the confirmed cases provided by the daily technical report COVID-19 MEXICO until May 8th. The mathematical models: Gompertz and Logistic, as well as the computational model: Artificial Neural Network were applied to carry out the modeling of the number of

The World Health Organization (WHO) declared novel coronavirus 2019 (COVID-19), an infectious epidemic caused by SARS-CoV-2, as Pandemic in March 2020. It has affected more than 40 million people in 216 countries. Almost in all the affected countries, the number of infected and deceased patients has been enhancing at a distressing rate. As the early prediction can reduce the spread of the virus, it

Since the new coronavirus (COVID-19) outbreak spread from China to other countries, it has been a curiosity for how and how long the number of cases will increase. This study aims to forecast the number of confirmed cases of COVID-19 in Italy, the United Kingdom (UK) and the United States of America (USA). In this study, grey model (GM(1,1)), nonlinear grey Bernoulli model (NGBM(1,1)) and fractional

The Coronavirus Disease 2019 (COVID-19) surges worldwide. However, massive imported patients especially into Heilongjiang Province in China recently have been an alert for local COVID-19 outbreak. We collected data from January 23 to March 25 from Heilongjiang province and trained an ordinary differential equation model to fit the epidemic data. We extended the simulation using this trained model to

Presently, COVID-19 has posed a serious threat to researchers, scientists, health professionals, and administrations around the globe from its detection to its treatment. The whole world is witnessing a lockdown like situation because of COVID-19 pandemic. Persistent efforts are being made by the researchers to obtain the possible solutions to control this pandemic in their respective areas. One of

We explore the evolution of the informational efficiency in 45 cryptocurrency markets and 16 international stock markets before and during COVID-19 pandemic. The measures of Largest Lyapunov Exponent (LLE) based on the Rosenstein's method and Approximate Entropy (ApEn), which are robust to small samples, are applied to price time series in order to estimate degrees of stability and irregularity in

This work aims to model, simulate and provide insights into the dynamics and control of COVID-19 infection rates. Using an established epidemiological model augmented with a time-varying disease transmission rate allows daily model calibration using COVID-19 case data from countries around the world. This hybrid model provides predictive forecasts of the cumulative number of infected cases. It also

We investigate the overdamped stochastic dynamics of a particle in an asymptotically flat external potential field, in contact with a thermal bath. For an infinite system size, the particles may escape the force field and diffuse freely at large length scales. The partition function diverges and hence the standard canonical ensemble fails. This is replaced with tools stemming from infinite ergodic

Currently, research of quadrotor unmanned aerial vehicles (QUAV) focuses on the design of the controller and optimization of the control algorithm. Dynamical analysis of the attitude system of QUAV has also been studied. In this paper, the stability of equilibrium points is further analyzed based on their distribution and bifurcation. Multi-initial phase-portraits demonstrate the multistability and

Let (X, d) be a compact metric space and φ: X⊸X be a multivalued map. At first, we will extend for these maps the notions of a topological entropy and Robinson’s chaos from a single-valued into a multivalued setting and show their basic properties. Then, for a subclass of multivalued continuous maps with compact values, we will clarify their relationship to the induced (hyper)maps φ*:K(X)→K(X) in the

The purpose of this paper is to analyze and control the hyperchaotic behaviours of a biological snap oscillator. We mainly study the chaos control and synchronization of a hyperchaotic model in both the frameworks of classical and fractional calculus, respectively. First, the phase portraits of the considered model and its hyperchaotic attractors are analyzed. Then two efficacious optimal and adaptive

Signal separation has many applications in different fields, such as biology. In real-world applications, sometimes, the combined signals are not independent, and their separation is not easy with common methods and needs proper approaches. In this paper, it is assumed that the summation of chaotic signals from one chaotic system is available, and the system's equations are known. The aim is to separate

In recent decades, studying the behavior of biological species has become one of the most fascinating areas of applied mathematics. The high importance of conservation of rare species in nature has prompted researchers in various fields to pay particular attention to this issue. Therefore, it is essential to develop mathematical models that examine the dynamics of their behavior. On the other hand

The outbreak and propagation of COVID-19 have posed a considerable challenge to modern society. In particular, the different restrictive actions taken by governments to prevent the spread of the virus have changed the way humans interact and conceive interaction. Due to geographical, behavioral, or economic factors, different sub-groups among a population are more (or less) likely to interact, and

In this paper, we have conducted analysis based on data obtained from National Institute of Health (NIH) - Islamabad and produced a forecast of COVID-19 confirmed cases as well as the number of deaths and recoveries in Pakistan using the Auto-Regressive Integrated Moving Average Model (ARIMA). The fitted forecasting models revealed high exponential growth in the number of confirmed cases, deaths and

The latest version of human coronavirus said to be COVID-19 came out as a sudden pandemic disease within human population and in the absence of vaccination and proper treatment till date, it daunting threats heavily to human lives, infecting more than 12, 11, 214 people and death more than 67, 666 people in 208 countries across the globe as on April 06, 2020, which is highly alarming. When no treatment

Global efforts around the world are focused on to discuss several health care strategies for minimizing the impact of the new coronavirus (COVID-19) on the community. As it is clear that this virus becomes a public health threat and spreading easily among individuals. Mathematical models with computational simulations are effective tools that help global efforts to estimate key transmission parameters

The recent Coronavirus has been spreading through all the world fastly. In this work we focus on the evolution of the COVID-19 in one of the most populous Brazilian states, namely the Rio de Janeiro state. The first case was reported in March 5, 2020, thus we have a considerable amount of available data to make a good analysis. We study the dynamics of COVID-19 through a Susceptible-Infectious-Quarantined-Recovered

We present results of different approaches to model the evolution of the COVID-19 epidemic in Argentina, with a special focus on the megacity conformed by the city of Buenos Aires and its metropolitan area, including a total of 41 districts with over 13 million inhabitants. We first highlight the relevance of interpreting the early stage of the epidemic in light of incoming infectious travelers from

In this paper, a general formulation for the SIRV epidemiological model is presented as a system of fractional order derivatives with respect to time to characterize some infectious diseases alongside the proportion of u1 and u2, that describe of vaccination and treatment, respectively. This fractional mathematical formulation is based on the fractional-order Caputo derivative. The stability of Equilibrium

In the present work, we introduce a stochastic SIRI epidemic model with nonlinear relapse. We give sufficient conditions for extinction and persistence of the disease. We also study the existence of a stationary distribution and the ergodicity of the solutions. As a special case of our results that under some conditions on noise intensities, we obtain the threshold Rβ for the disease. Finally, we provide

In this paper, we study the dynamical behaviors of a SVI epidemic model with half saturated incidence rate. Firstly, the local asymptotic stability of the endemic and disease-free equilibria of the deterministic model are studied. Then for stochastic model, we show that there is a critical value R0s which can determine the extinction and the persistence in the mean of the disease. Furthermore, by constructing

The attitude, silent or speaking, and the behavior, cooperation or betrayal, are two interrelated and mutually influential attributes of individuals. In the context of environmental dilemma, four strategies are determined depending on two factors mentioned. In this paper, a new analytic framework is built to take care of those four types of groups - silent cooperator, speaking cooperator, silent defector

We analyse how the interplay between several sources of heterogeneity in agent’s bias, namely plurality and polarization, shapes the emergence of different regimes of collective opinion in multi-agent systems. We do so by considering a kinetic-like model of opinion dynamics with restrictive pairwise interactions — which are modeled by a smooth bounded confidence — in a networked population endued with

Stochastic commodity price models play a significant role in the pricing and hedging of commodity derivatives and real assets. This paper proposes a commodity pricing model that extends the Ewald and Ouyang two-factor model by adding a time-varying function into the volatility term of convenience yield process to describe seasonality. The stochastic factors in the model are the spot price of the commodity

This manuscript introduces the square-mean doubly weighted pseudo almost automorphy and also square-mean doubly weighted pseudo almost automorphy in the sense of Stepanov (Sl2) over time scales. We derive results for a general stochastic dynamic system on time scales which can model a stochastic cellular neural network with time shifting delays on time scales. The coefficients are considered to be

In this report, we analyze historical and forecast infections for COVID-19 death based on Reduced-Space Gaussian Process Regression associated to chaotic Dynamical Systems with information obtained in 82 days with continuous learning, day by day, from January 21th, 2020 to April 12th. According last results, COVID-19 could be predicted with Gaussian models mean-field models can be meaning- fully used

It has been more than four decades since ideas from chaos began appearing in the literature showing that it is possible to design economic models in regime of chaotic behaviour from a theoretical point of view. However there is no clear evidence that economic time series behave chaotically. So far researchers have found substantial evidence for nonlinearity but relatively weak evidence for chaos. In

In this paper, we propose dispersion Lempel–Ziv complexity and combine it with dispersion entropy to construct complexity-entropy plane. This measure aims to identify time series with different properties. These two quantities take advantage of nonlinear symbolic representation and quantify the complexity of series. In addition, they are relatively stable for different parameters and robust against

The problem of the existence of a Nash equilibrium strategy in a state feedback form is discussed for a class of stochastic linear quadratic two players differential games. It is assumed that only measurements at discrete-time instances of the state parameters are available. Both piecewise continuous admissible strategies as well as piecewise constant admissible strategies are considered.

We describe in this paper an analysis of the spatial evolution of coronavirus pandemic around the world by using a particular type of unsupervised neural network, which is called self-organizing maps. Based on the clustering abilities of self-organizing maps we are able to spatially group together countries that are similar according to their coronavirus cases, in this way being able to analyze which

The realization of real memristor makes it be a very popular topic in recent years. However, the topic about discrete memristor model is rarely discussed. In this paper, a discrete memristor model is proposed based on the difference theory, and the three fingerprints characteristics are proved for this model according to the definition of the generalized memristor. This discrete model is applied to

Plants are really important for the planet and for all living things. Plants absorb carbon dioxide and release oxygen from their leaves, which humans and other animals need to breathe. Living things need plants to live - they eat them and live on them. Therefore, understanding plant disease dynamics is important as it can provide insightful knowledge on plant disease transmission. So, in this work

Considering soccer matches as complex systems facilitates the identification of properties that emerge from the interactions between players. Such properties include the regularities and statistical patterns that characterize couplings and sets between players established during matches. Empirical studies on the statistical distributions of number of items (e.g., words in texts) have shown that these

A drone based on four rotors is considered in this research paper. Its chaotic solution is shown bounded in an inscribed sphere whose vertices are tangent to faces of octahedron. Based on concept of constrained optimization; Linear Matrix Inequalities (LMIs) satisfying quadratic constraint increment multiplier matrix σm, state observers and descriptors with estimated parameter is calculated. Moreover

So-called (u, v)-flowers are recursive networks which produce self-similar structures with fractality or the small-world property. This paper generalises (u, v)-flowers by introducing probabilities into the realisations of u and v, which enables the study of intermediate states between small and non-small worlds in fractal networks. We obtain the analytical relation between the diameter of the graph

Network Science provides a universal formalism for modelling and studying complex systems based on pairwise interactions between agents. However, many real networks in the social, biological or computer sciences involve interactions among more than two agents, having thus an inherent structure of a simplicial complex. The relevance of an agent in a graph network is given in terms of its degree, and

We propose an extended spatial evolutionary public goods game (SEPGG) model to study the dynamics of individual career choice and the corresponding social output. Based on the social value orientation theory, we study the game dynamics of players choosing from two types of work, namely the public work if it serves public interests, and the private work if it serves personal interests. Under the context

To improve the chaos complexity of existing chaotic maps, the fractional difference form of sine chaotification model (FSCM) is proposed in this paper based on discrete fractional calculus. In order to show its effect, we apply it to three chaotic maps. And the bifurcation diagrams and Lyapunov exponent of the generated new map are studied numerically. The experimental results show that FSCM has more

In this paper, the effects of a threshold electromagnetic induction, as well as an asymmetry in the electrical synaptic coupling between two neuronal oscillators, are studied through a 2D Hindmarsh-Rose model. We have found that the introduced model has no-equilibrium point and thus, displays hidden dynamics. We equally demonstrate that the electromagnetic induction strength combined with an asymmetric

It is estimated that, about one billion people mostly from Asia, Sub-Saharan Africa and Latin America are infected with the Hookworm infection. In this paper, we developed and analyzed a model for the transmission dynamics of Hookworm infection in a human population using Caputo fractional order differential operator. Under Caputo operator, existence and uniqueness for the solutions of the new Hookworm

Understanding the early transmission dynamics of diseases and estimation of the effectiveness of control policies play inevitable roles in the prevention of epidemic diseases. To this end, this paper is concerned with the design of optimal control strategies for the novel coronavirus (COVID-19). A mathematical model of severe SARS-CoV-2 transmission based on Wuhan's data is considered in this study

To solve the unreasonable allocation problem of network security defense resource, this paper presents a framework for optimal defense resource allocation for minimizing the network risk. The vulnerability power function model of network nodes is built based on nonlinear theory between defense resource and network vulnerability. The network risk assessment model is described by vulnerability model

Present paper analyzes the bursting dynamics of a smallest chemical reaction system with multi-frequency slow parametric excitations (referred as SCRSMFSPEs hereafter), in which four novel bursting patterns, i. turnover-of-transcritical-hysteresis-induced bursting, ii. cascaded transcritical-hysteresis bursting, iii. turnover-of-transcritical-hysteresis/supHopf-induced compound bursting and iv. cascaded

A phenomenon of the noise-induced oscillatory transitions in a predator-prey model of Leslie type with generalized Holling type III functional response is studied. The original deterministic model can exhibit different kinds of phase portraits (one, two or three stable states) for various parameter values. When the predator-prey model is subjected to environmental noise, we find that the stochastic

The aim of this study is to explore the behavior of perpetual game put options, also known as cancellable puts. Their main characteristic is the opportunity of the buyer and the seller to exercise prematurely. If the seller decides to terminate the option, he obliges to pay a penalty amount above the normal option fee. We include also a discount factor that provides an advantage for earlier option