1,721,125 research outputs found
Cellular Nonlinear Networks: Analysis, Design and Applications
No full textL'obiettivo della tesi è lo studio degli aspetti teorici ed applicativi delle reti elettriche non lineari (con particolare riferimento alle reti non lineari cellulari
Tunable chaos in memristor circuits for pattern recognition tasks
No full textThe work focuses on pattern classification via analog systems that exploit tunable chaos in 3rd-order memristor-based Chua's circuits obtained by replacing the nonlinear resistor with an ideal flux-controlled memristor. Recently, complex dynamics and synchronization phenomena have been investigated via manifolds which are positively invariant for the nonlinear dynamics. Moreover, on each manifold the network obeys a different reduced-order dynamics in the flux-charge domain. These basic properties imply that two main types of bifurcations can occur, i.e., standard bifurcations on a fixed invariant manifold induced by changing the circuit parameters and bifurcations due to the variation of initial conditions and invariant manifold, but for fixed circuit parameters. The latter bifurcation phenomena are referred to as bifurcations without parameters and can be also induced by suitable pulses to tune the dynamical attractors. The reduced dynamics on invariant manifolds, and their analytic expressions, are the key tools for a comprehensive analysis of synchronization phenomena in networks of memristor-based Chua's circuits. Such complex phenomena are the chief properties to realize analog systems for pattern recognition
Memristor based-elements for chaotic circuits
No full textThe peculiar features of the memristor, a fundamental passive two-terminal element characterized by nonlinear relationship between charge and flux, promise to revolutionize integrated circuit design in the next few decades. Besides its most popular potential applications, ultra-dense non-volatile memories and brain-simulating systems, much research has been lately devoted to their use in chaotic circuits. Although the physical memristor is inherently-asymmetric, complementary behaviors arise in devices with opposite polarity. In this work we demonstrate that this makes it feasible to devise a number of practical realizations of a monotone-increasing odd-symmetric charge-flux nonlinearity suitable for chaos-based applications through the sole use of physical memristors of the kind recently fabricated at Hewlett-Packard Labs. Confirmation for such claim is obtained through comparison of chaotic behavior of two modified Chua's oscillators, in which the nonlinear diode is replaced in one case with an artificial memristor with symmetric nonlinearity and in the other case with one of the proposed symmetric memristor combinations
Comparison between the Dynamic Behavior of Chua-Yang and Full-Range Cellular Neural Networks
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