Duy Vo Hoang

A No-Equilibrium Hyperchaotic System and Its Fractional-Order Form

No-equilibrium system with chaotic behavior has attracted considerable attention recently because of its hidden attractor. We study a new four-dimensional system without equilibrium in this work. The new no-equilibrium system exhibits hyperchaos and coexisting attractors. Amplitude control feature of the system is also discovered. The commensurate fractional-order version of the proposed system is studied using numerical simulations. By tuning the commensurate fractional-order, the proposed system displays a wide variety of dynamical behaviors ranging from coexistence of quasiperiodic and chaotic attractors and bistable chaotic attractors to point attractor via transient chaos.

A Chaotic System with Two Stable Equilibrium Points: Dynamics, Circuit Realization and Communication Application

Recent evidence suggests that a system with only stable equilibria can generate chaotic behavior. In this work, we study a chaotic system with two stable equilibrium points. The dynamics of the system is investigated via phase portrait, bifurcation diagram and Lyapunov exponents. The feasibility of the system is introducing its electronic realization. Moreover, the chaotic system is used in Symmetric Chaos Shift Keying (SCSK) and Chaotic ON-OFF Keying (COOK) modulated communication designs for secure communication. It is determined that the SCSK modulated communication system implemented with the chaotic system is more successful than COOK modulation for secure communication.

Chaos in a System with an Absolute Nonlinearity and Chaos Synchronization

A system with an absolute nonlinearity is studied in this work. It is noted that the system is chaotic and has an adjustable amplitude variable, which is suitable for practical uses. Circuit design of such a system has been realized without any multiplier and experimental measurements have been reported. In addition, an adaptive control has been applied to get the synchronization of the system.

A fractional system with five terms: analysis, circuit, chaos control and synchronization

ABSTRACT By introducing fractional derivative, fractional chaotic systems were proposed. A new fractional system with chaos is presented in our work. It is interesting that the system is elegant including only five terms. By using electronic components, we realize the five-term fractional system. Experimental results show chaos of the circuit. Chaos control as well as synchronization of such a five-term fractional system has been investigated.

Dynamic system with no equilibrium and its chaos anti-synchronization

ABSTRACT Recently, systems with chaos and the absence of equilibria have received a great deal of attention. In our work, a simple five-term system and its anti-synchronization are presented. It is special that the system has a hyperbolic sine nonlinearity and no equilibrium. Such a system generates chaotic behaviours, which are verified by phase portraits, positive Lyapunov exponent as well as an electronic circuit. Moreover, the system displays multistable characteristic when changing its initial conditions. By constructing an adaptive control, chaos anti-synchronization of the system with no equilibrium is obtained and illustrated via a numerical example.

Demographic data and remote sensing to monitor urban growth: the Ho Chi Minh City (Vietnam) case study

In the last decades Ho Chi Minh City (HCMC), Vietnam, has experienced a rapid urbanization. This town grows from 2.3 millions of inhabitants in the 1975 until 8 millions in the 2014. Therefore, understanding the land-cover changes is one of the main topics in order to monitor the process of urban development. In this paper we study the urban dynamics of HCMC using two Landsat scenes acquired on June of 1988 (sensor TM) and on February 2017 (sensor OLI/TIRS). We relate our main results with other sources, like demographic data and the participative maps of OpenStreetMap. So, we identify main land cover changes in this period, such as the most important demographic variations within the urban districts of HCMC.

A novel approach on evolutionary dynamics analysis - A progress report

Abstract In this paper, we discuss the possibility of unique mutual fusion of evolutionary algorithms, complex networks, strange dynamics and hidden attractors. As demonstrated in many research papers, evolutionary algorithms are capable of very complex tasks such as chaotic system control, identification or synthesis and vice versa; chaos can also be observed in the evolutionary dynamics, as originally demonstrated by various researchers. We propose a novel approach on how to analyze and control dynamic of the evolutionary algorithm and also discuss the possibility of strange dynamics analysis that can be a part of dynamic of evolutionary algorithms. In any words, we propose to understand algorithms as a discrete dynamical system that exhibits a wide spectrum of the behavior that can be controlled and analyzed.

Analytic Programming Powered by Chaotic Dynamics

In this paper we discuss alternative tool for symbolic regression so called Analytical programming and compare its variants powered by classical random as well as chaotic random-like number generator. Experimental data are used from the previous experiments reported for genetic programming. Selected algorithms are differential evolution, SOMA, particle swarm, simulated annealing and evolutionary strategies. All of them are mutually used in scheme Master-Slave meta-evolution for final complex structure fitting and its parameter estimation.

Chaos Level Measurement in Logistic Map Used as the Chaotic Numbers Generator in Differential Evolution

In present time some researchers use chaotic numbers generators in evolutionary algorithms like differential evolution, SOMA or particle swarm optimization. These chaotic numbers generators are based on chaotic discrete systems which replace pseudorandom numbers generators like Mersenne Twister, Xorshift etc. In this paper we will investigate the influence of chaos level in logistic map which is used as chaotic numbers generator to the convergence’s speed of differential evolution to the global minimum of testing functions.