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Design and application examples of CMOS fractional-order differentiators and integrators

Reduced complexity CMOS fractional-order differentiator and integrator building blocks are introduced in this work, based on 2 nd -order integer-order transfer function approximations. These blocks are then used for implementing fractional-order filters as well as a Leaky-Integrate-and-Fire Mihalas-Niebur neuron model. Cascading 1 st and 2 nd -order blocks to obtain 5 th -order integer-order transfer functions, improved bandwidth of approximation accuracy is achieved. Furthermore, the realization of fractional-order capacitor and inductor emulators is demonstrated. © 2018 Elsevier Ltd

Circuit Theory and Applications

On a class of quadrature phase oscillators using differential pairs

A new class of quadrature phase oscillators based on cross-coupled differential pairs is introduced. This class contains eight possible circuits which produce four output voltages with phase differences of ±π or ±π/2, depending on the choice of output node, and does not require balanced differential-pair loads. Phase error analysis is provided along with experimental and simulation results using discrete MOS and BJT transistors as a proof of concept. © 2018 IEEE

Circuit Theory and Applications

Generalized double-humped logistic map-based medical image encryption

This paper presents the design of the generalized Double Humped (DH) logistic map, used for pseudo-random number key generation (PRNG). The generalized parameter added to the map provides more control on the map chaotic range. A new special map with a zooming effect of the bifurcation diagram is obtained by manipulating the generalization parameter value. The dynamic behavior of the generalized map is analyzed, including the study of the fixed points and stability ranges, Lyapunov exponent, and the complete bifurcation diagram. The option of designing any specific map is made possible through

Circuit Theory and Applications

A Novel Power-Aware Task Scheduling for Energy Harvesting-Based Wearable Biomedical Devices Using FPA

Power management and saving in energy harvesting-based biomedical wearable devices are mandatory to ensure prolonged and stable operation under a stringent power budget. Thus, power-aware task scheduling can play a key role in minimizing energy consumption to improve system durability while maintaining device functionality. This paper proposes a novel biosensor task scheduling for optimizing energy consumption through wearable biomedical devices. The proposed approach is based on Flower Pollination Algorithm (FPA). The biomedical functionality constraints are enforced with a Hamming-based

Circuit Theory and Applications

Dynamics of fractional and double-humped logistic maps versus the conventional one

This paper presents the dynamic analysis of two discrete logistic chaotic maps versus the conventional map. The first map is the fractional logistic map with the extra degrees of freedom provided by the added number of variables. It has two more variables over the conventional one. The second map is the double-humped logistic map. It is a fourth-order map which increases the non-linearity over the conventional one. The dynamics of the three maps are discussed in details, including mathematical derivations of fixed points, stability analysis, bifurcation diagrams and the study of their chaotic

Circuit Theory and Applications

Generalized fractional logistic map encryption system based on FPGA

This paper introduces the design of a generalized fractional order logistic map suitable for pseudorandom number key generators and its application in an encryption system based on FPGA. The map is generalized through two parameters (a,b) where complete analysis of their effect on the map is detailed, which gives more control on the map chaotic regions. The vertical map and the zooming map presented in this paper are two special maps extracted from the generalized map with their detailed analysis. Not only the positive bifurcation, but also the negative side is discussed through this paper

Circuit Theory and Applications

Plant stem tissue modeling and parameter identification using metaheuristic optimization algorithms

Bio-impedance non-invasive measurement techniques usage is rapidly increasing in the agriculture industry. These measured impedance variations reflect tacit biochemical and biophysical changes of living and non-living tissues. Bio-impedance circuit modeling is an effective solution used in biology and medicine to fit the measured impedance. This paper proposes two new fractional-order bio-impedance plant stem models. These new models are compared with three commonly used bio-impedance fractional-order circuit models in plant modeling (Cole, Double Cole, and Fractional-order Double-shell). The
Circuit Theory and Applications

Fractional-Order Generalized Gene Regulation Model CCII-Based Practical Emulator

This paper presents a practical emulator of a generalised fractional-order model for gene regulation process, in an analog platform. The presented emulator is based on the second-generation current conveyor (CCII) and implemented using AD844 chips. The emulator realises a proposed generalised mathematical model for gene expression. The model sums up three different single models; the constitutive gene model, the induced gene expression under the effect of activators and repressors models. The generalised model is based on fractional-order differential equations where the concentration of the

Circuit Theory and Applications

Generic Hardware of Fractional Order Multi-Scrolls Chaotic Generator Based on FPGA

Exploring the implementation of fractional calculus is essential to be adequately used in several applications. This paper introduces an FPGA design methodology of fractional order multi-scrolls chaotic system. Hardware resources comparison proves the efficiency of the proposed method. The designs are simulated using Xilinx ISE 14.7 and realized on FPGA Xilinx Artix 7. Different interesting attractors are realized under various parametric changes with distinct step sizes for different fractional-orders. To verify the proposed fractional order multi-scrolls chaotic system on FPGA, experimental

Circuit Theory and Applications

A novel image encryption system merging fractional-order edge detection and generalized chaotic maps

This paper presents a novel lossless image encryption algorithm based on edge detection and generalized chaotic maps for key generation. Generalized chaotic maps, including the fractional-order, the delayed, and the Double-Humped logistic maps, are used to design the pseudo-random number key generator. The generalization parameters add extra degrees of freedom to the system and increase the keyspace achieving more secure keys. Fractional order edge detection filters exhibited better noise robustness than the conventional integer-order ones, rendering the system to be suitable for medical

Circuit Theory and Applications