Ismail Ozturk

• PhD
• Amasya University

This paper investigates cycle and transient lengths of spatially discretized chaotic maps with respect to different initial condition values. By investigating cycle lengths and their correlation properties using fixed point arithmetic, it is observed that for different initial condition values only a limited number of cycles occur for each resoluti...

It is impossible to obtain chaotic behavior using conventional finite precision calculations on a digital platform. All such realizations are eventually periodic. Also, digital calculations of the periodic orbits are often erroneous due to round-off and truncation errors. Because of these errors, periodic orbits quickly diverge from the true orbit...

Chaotic systems cannot be realized using fixed or floating point arithmetic on a digital platform. Implementations using these methods always yield periodic and erroneous orbits which are not predicted by the original mathematical method. Also, using such implementations in cryptography is not appealing, because classical cryptography mostly deals...

Digital realizations of chaos-based cryptosystems suffer from lack of a reliable method for implementation. The common choice for implementation is to use fixed or floating-point arithmetic directly. However, such an approach produces unreliable and erroneous pseudo-chaotic orbits, which are not the original orbits of the chaotic map. Also, using f...

The Spike-Time-Dependent-Plasticity (STDP) learning rule is frequently associated with the memristor structures in the neuromorphic studies, recently. In this study, after two HR neurons are coupled with a memristor based synapse structure as a unidirectional coupling; it is aimed to correlate the STDP learning rule and the memristor based synapse...

A new three dimensional ordinary differential equation-based chaotic system is proposed in this paper. Unlike the majority of the chaotic systems available in the literature, the proposed system has a hyperbolic and a non-hyperbolic equilibrium. The dynamical behavior of the system is investigated by the analysis of eigenvalues, bifurcation diagram...

Neuromorphic engineering is a discipline used to develop hardware, which can mimic the characteristics and abilities of biological systems by investigating their physiological structures and data transfer mechanisms. The recent studies about the neuromorphic systems mostly consist of robotic applications whose designs are inspired by Central Patter...

In the literature, the parabolic function of the Izhikevich Neuron Model (IzNM) is transformed to the Piecewise Linear (PWL) functions in order to make digital hardware implementations easier. The coefficients in this PWL functions are identified by utilizing the error-prone classical step size method. In this paper, it is aimed to determine the co...

Although there are a lot of studies on realization of electrical coupling in HR neuron model, the investigation of chemical coupling with hardware implementations is limited because of implementation complexities. In this paper, it is aimed to present alternative analog and digital hardware solutions for investigating the chemical coupling in the H...

A few individual design examples of programmable device-based biological neuron model implementations are available in the literature, but there is no comprehensive study that examines analog and digital programmable design examples of frequently studied biological neuron model implementations. The aim of this paper is to present a comparative stud...

In this paper, a novel method is proposed for producing pseudo random numbers from differential equation-based chaotic systems. The proposed method utilizes a Lü-like chaotic system capable of exhibiting both Lorenz-like and Chen-like chaotic system behaviors for different parameter values. A parameter switching process controlled by a linear feedb...

In this paper, versatile implementations of PWL-based multiscroll chaos generator have been comprehensively examined in the scope of programmable solutions, both analog and digital, and discrete component realization. To this end, PWL-based multiscroll chaos generator has been implemented using FPAA/FPGA devices and generally known discrete compone...

This study presents experimental realizations of the HR neuron model with programmable hardware and synchronization applications. The HR neuron model exhibiting burst, spike, and chaotic dynamics has been implemented with both FPAA (Field Programmable Analog Array) and FPGA (Field Programmable Gate Array) devices. These devices provide flexible des...

In this study, Izhikevich Neuron Model, which can be exhibited different behaviors, is implemented experimentally with programmable devices, FPGA (Field Programmable Gate Array) and FPAA (Field Programmable Analog Array). After testing the behaviors of neuron models through numerical analyses, the experimental setups are constructed with programmab...