This paper introduces a novel magnitude approximation for the fractional-order Chebyshev low-pass filter. The proposed magnitude response is constructed from the fractional Chebyshev polynomials originating from the series solution of fractional-order Chebyshev differential equation. The transfer function of the fractional-order Sallen-Key biquad is used as a prototype for the approximation. To identify the coefficients of the Sallen-Key topology, the flower pollination algorithm (FPA) is used to minimize an objective function representing the sum of relative magnitude error. The optimization problem is executed in MATLAB, and stable solutions are chosen for the implementation. Two different cases are investigated corresponding to filter orders 1.8 and 2.7. LT-Spice is used for circuit simulations, and the Valsa approach is used for fractional-order capacitor approximation. The original magnitude response is compared with the optimized one and the circuit simulation results, and this comparison shows a magnitude error less than 2%. © 2021 IEEE.
Double Fractional-order Masks Image Enhancement
Image enhancement is better achieved when fractional-order masks are used rather than integer-order ones, this is due to the flexibility of fractional-order parameters control. This paper proposes a combination of fractional-order masks to be used in parallel as double filters system structure to improve image enhancement rather than using a single-stage filter. Various performance metrics are used in this work to evaluate the proposed system, such as Information Entropy (IE), Average Gradient (AG), Structural Similarity Index Metric (SSIM) and Peak Signal to Noise Ratio (PSNR). Based on visual as well as numerical results, it is found that the combination of two double masks is superior to the single fractional-order system in terms of enhancing texture and edges. © 2021 IEEE.
Different Approximation Techniques For A FOPID Feedback Control of a DC Motor
DC motors are commonly employed in many industrial applications due to their various advantages. This study aims to compare the response of the Oustaloup-Recursive-Approximation (ORA) and El-Khazali’s approximation method in controlling a DC motor with a FOPID controller. The two employed methods are used to design the FOPID and approximate. For various fractional orders, many behaviours are presented. A simulation comparison between these methods is performed regarding overshoot, settling time and rise time. © 2022 IEEE.
Blind Watermarking Using DCT and Fractional-Order Lorenz System
This paper presents a new blind watermarking system based on the Discrete Cosine Transform (DCT). The system’s security is increased by encrypting the watermark image using the fractional-order Lorenz system. After converting the cover image to the YCbCr color domain, DCT is applied on the Y channel and embedding of the encrypted watermark is performed in the frequency domain. The fractional-order Lorenz system has more parameters than the integer order system, which increase the length of the system key and make it secure against brute-force attacks. Although blind detection of the watermark is not easy, the proposed algorithm successfully detects the hidden watermark by using statistical properties of the DCT coefficients. Standard imperceptibility and robustness measures are used to evaluate the proposed system, and the results are good. © 2022 IEEE.
Progressive Multi-Secret Sharing of Color Images Using Lorenz Chaotic System
Multi-Secret Image Sharing (MSIS) systems share multiple images to multiple participants in unintelligible forms that can be recovered using all the shares. This paper employs the concept of progressive secret sharing with MSIS to introduce a new system, where the number of used shares in the recovery process defines the quality of the recovered secrets. The proposed system works for any number of secret color images, and is lossless when all the shares are present. The Lorenz chaotic system, which is numerically solved using Euler method, is used as source of randomness to encrypt the secret images. Image encryption utilizes a long system key to perform the substitution and permutation stages. The system passes all security tests, including statistical analysis and key sensitivity, and it is also robust to noise and crop attacks. The analysis results are within the required ranges for a good encryption system, and they are better than those of the compared MSIS systems. © 2023 IEEE.
Time-domain Li-ion Battery Modeling under Staircase Charging and Discharging
Parameter identification of Li-ion battery models is important for efficiently charge and discharge the most widely used energy storage devices. In this work, we propose a simplified battery model with a parameter identification method for time-domain charging and discharging. Staircase PotentioElectrochemical Impedance Spectroscopy technique (SPEIS) is chosen to characterize the batteries during charging and discharging cycles at different voltage steps values. Marine Predator Algorithm (MPA) is used to identify the proposed model parameters on two commercial Li-ion coin-shaped batteries. The proposed model shows very good matching with the experiments with absolute current error less than 10 4. Hence, the proposed model can be used for real-time applications to predict the battery’s behavior under different operating conditions. © 2021 IEEE.
On Fractional-order Capacitive Wireless Power Transfer System
Wireless power transfer is becoming an increasingly viable solution for the electrical powering of various electronic gadgets. However, precise outputs are not guaranteed with integer systems, so fractional-order capacitors are vital. This paper studies a four-plate fractional capacitive power transfer system by varying six orders of capacitors between the plates along with the load resistance. A mathematical model based on a 4× 4 mutual fractional capacitance matrix is established for equidistantly placed four identical metal plates. Moreover, the chosen circuit topology is identified and analyzed based on the proposed model. © 2022 IEEE.
Do the Bio-impedance Models Exhibit Pinched Hysteresis?
Recently, pinched hysteresis has been found in the electrical modelling of regular plant tissues. Usually, the biological tissues are characterized in the frequency domain using bio-impedance analyzers without investigating the time domain, which would show the pinched hysteresis. In this paper, the current-voltage analysis of some of the widely known electrical bio-impedance models is studied. The investigated models are the single dispersion Cole-impedance model, the double dispersion Cole-impedance model and the fractional-order simplified Hayden model to prove that these models can not exhibit pinched hysteresis. It is proved mathematically in this paper that there are no pinch-off points that would exist in these models. These results are verified with numerical simulations of three different plants: tomato, carrot and banana, concluding that the bioimpedance modelling needs a nonlinear element to model the pinched hysteresis in the current-voltage behaviour of these tissues. © 2020 IEEE.
Comparison of Different Implementation Methods of Fractional-Order Derivative/Integral
Implementing a fractional-order operator requires many resources to acquire an accurate response compared to the theoretical response. In this paper, three implementation methods of digital fractional-order operators are exploited. The three implementation methods are based on FIR, IIR, and lattice wave digital filters. The three methods are implemented using different optimization algorithms to optimize the choice of the coefficients of the three filters. This optimization is done to approximate the frequency response of an ideal fractional operator. This comparison aims to determine each implementation method’s accuracy and resource usage level to decide which method is better for different systems. © 2021 IEEE.
On Series Connections of Fractional-Order Elements and Memristive Elements
This paper proposes a current-controlled fractional-order memristor emulator based on one active building block. The emulator consists of a multiplication mode current conveyor (MMCC) block with three passive elements. Additionally, the series connection of fractional-order inductor (FOI) and fractional-order capacitor (FOC) with memristive elements in the i-v plane is demonstrated numerically for different cases. Changing the order of the FOC or FOI and its effect on the pinched hysteresis loop area are investigated, which improve the controllability of the double loop area, the location of the pinched point, and the operating frequency range. Numerical, PSPICE simulation results, and experimental verification are investigated for different cases to approve the theoretical findings. Moreover, a sensitivity analysis using Monte Carlo simulations for the tolerance of the discrete components of the memristor emulator is investigated. © 2020 IEEE.