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Open AccessEditorial

Complex and Fractional Dynamics

by J. A. Tenreiro Machado and António M. Lopes

Entropy 2017, 19(2), 62; https://doi.org/10.3390/e19020062 - 8 Feb 2017

Cited by 8 | Viewed by 3924

Abstract

Complex systems (CS) are pervasive in many areas, namely financial markets; highway transportation; telecommunication networks; world and country economies; social networks; immunological systems; living organisms; computational systems; and electrical and mechanical structures. CS are often composed of a large number of interconnected and [...] Read more.

Complex systems (CS) are pervasive in many areas, namely financial markets; highway transportation; telecommunication networks; world and country economies; social networks; immunological systems; living organisms; computational systems; and electrical and mechanical structures. CS are often composed of a large number of interconnected and interacting entities exhibiting much richer global scale dynamics than could be inferred from the properties and behavior of individual elements. [...]
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(This article belongs to the Special Issue Complex and Fractional Dynamics)

Research

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5283 KiB

Open AccessArticle

Chaos on the Vallis Model for El Niño with Fractional Operators

by Badr Saad T. Alkahtani and Abdon Atangana

Entropy 2016, 18(4), 100; https://doi.org/10.3390/e18040100 - 23 Mar 2016

Cited by 24 | Viewed by 5772

Abstract

The Vallis model for El Niño is an important model describing a very interesting physical problem. The aim of this paper is to investigate and compare the models using both integer and non-integer order derivatives. We first studied the model with the local [...] Read more.

The Vallis model for El Niño is an important model describing a very interesting physical problem. The aim of this paper is to investigate and compare the models using both integer and non-integer order derivatives. We first studied the model with the local derivative by presenting for the first time the exact solution for equilibrium points, and then we presented the exact solutions with the numerical simulations. We further examined the model within the scope of fractional order derivatives. The fractional derivatives used here are the Caputo derivative and Caputo–Fabrizio type. Within the scope of fractional derivatives, we presented the existence and unique solutions of the model. We derive special solutions of both models with Caputo and Caputo–Fabrizio derivatives. Some numerical simulations are presented to compare the models. We obtained more chaotic behavior from the model with Caputo–Fabrizio derivative than other one with local and Caputo derivative. When compare the three models, we realized that, the Caputo derivative plays a role of low band filter when the Caputo–Fabrizio presents more information that were not revealed in the model with local derivative. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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240 KiB

Open AccessArticle

A Novel Weak Fuzzy Solution for Fuzzy Linear System

by Soheil Salahshour, Ali Ahmadian, Fudziah Ismail and Dumitru Baleanu

Entropy 2016, 18(3), 68; https://doi.org/10.3390/e18030068 - 11 Mar 2016

Cited by 8 | Viewed by 4590

Abstract

This article proposes a novel weak fuzzy solution for the fuzzy linear system. As a matter of fact, we define the right-hand side column of the fuzzy linear system as a piecewise fuzzy function to overcome the related shortcoming, which exists in the [...] Read more.

This article proposes a novel weak fuzzy solution for the fuzzy linear system. As a matter of fact, we define the right-hand side column of the fuzzy linear system as a piecewise fuzzy function to overcome the related shortcoming, which exists in the previous findings. The strong point of this proposal is that the weak fuzzy solution is always a fuzzy number vector. Two complex and non-complex linear systems under uncertainty are tested to validate the effectiveness and correctness of the presented method. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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719 KiB

Open AccessArticle

Stability Analysis and Synchronization for a Class of Fractional-Order Neural Networks

by Guanjun Li and Heng Liu

Entropy 2016, 18(2), 55; https://doi.org/10.3390/e18020055 - 6 Feb 2016

Cited by 25 | Viewed by 5733

Abstract

Stability of a class of fractional-order neural networks (FONNs) is analyzed in this paper. First, two sufficient conditions for convergence of the solution for such systems are obtained by utilizing Gronwall–Bellman lemma and Laplace transform technique. Then, according to the fractional-order Lyapunov second [...] Read more.

Stability of a class of fractional-order neural networks (FONNs) is analyzed in this paper. First, two sufficient conditions for convergence of the solution for such systems are obtained by utilizing Gronwall–Bellman lemma and Laplace transform technique. Then, according to the fractional-order Lyapunov second method and linear feedback control, the synchronization problem between two fractional-order chaotic neural networks is investigated. Finally, several numerical examples are presented to justify the feasibility of the proposed methods. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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204 KiB

Open AccessArticle

Particular Solutions of the Confluent Hypergeometric Differential Equation by Using the Nabla Fractional Calculus Operator

by Resat Yilmazer, Mustafa Inc, Fairouz Tchier and Dumitru Baleanu

Entropy 2016, 18(2), 49; https://doi.org/10.3390/e18020049 - 5 Feb 2016

Cited by 19 | Viewed by 4931

Abstract

In this work; we present a method for solving the second-order linear ordinary differential equation of hypergeometric type. The solutions of this equation are given by the confluent hypergeometric functions (CHFs). Unlike previous studies, we obtain some different new solutions of the equation [...] Read more.

In this work; we present a method for solving the second-order linear ordinary differential equation of hypergeometric type. The solutions of this equation are given by the confluent hypergeometric functions (CHFs). Unlike previous studies, we obtain some different new solutions of the equation without using the CHFs. Therefore, we obtain new discrete fractional solutions of the homogeneous and non-homogeneous confluent hypergeometric differential equation (CHE) by using a discrete fractional Nabla calculus operator. Thus, we obtain four different new discrete complex fractional solutions for these equations. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

258 KiB

Open AccessArticle

New Derivatives on the Fractal Subset of Real-Line

by Alireza Khalili Golmankhaneh and Dumitru Baleanu

Entropy 2016, 18(2), 1; https://doi.org/10.3390/e18020001 - 29 Jan 2016

Cited by 45 | Viewed by 6809

Abstract

In this manuscript we introduced the generalized fractional Riemann-Liouville and Caputo like derivative for functions defined on fractal sets. The Gamma, Mittag-Leffler and Beta functions were defined on the fractal sets. The non-local Laplace transformation is given and applied for solving linear and [...] Read more.

In this manuscript we introduced the generalized fractional Riemann-Liouville and Caputo like derivative for functions defined on fractal sets. The Gamma, Mittag-Leffler and Beta functions were defined on the fractal sets. The non-local Laplace transformation is given and applied for solving linear and non-linear fractal equations. The advantage of using these new nonlocal derivatives on the fractals subset of real-line lies in the fact that they are better at modeling processes with memory effect. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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1039 KiB

Open AccessArticle

Predicting Traffic Flow in Local Area Networks by the Largest Lyapunov Exponent

by Yan Liu and Jiazhong Zhang

Entropy 2016, 18(1), 32; https://doi.org/10.3390/e18010032 - 19 Jan 2016

Cited by 13 | Viewed by 5428

Abstract

The dynamics of network traffic are complex and nonlinear, and chaotic behaviors and their prediction, which play an important role in local area networks (LANs), are studied in detail, using the largest Lyapunov exponent. With the introduction of phase space reconstruction based on [...] Read more.

The dynamics of network traffic are complex and nonlinear, and chaotic behaviors and their prediction, which play an important role in local area networks (LANs), are studied in detail, using the largest Lyapunov exponent. With the introduction of phase space reconstruction based on the time sequence, the high-dimensional traffic is projected onto the low dimension reconstructed phase space, and a reduced dynamic system is obtained from the dynamic system viewpoint. Then, a numerical method for computing the largest Lyapunov exponent of the low-dimensional dynamic system is presented. Further, the longest predictable time, which is related to chaotic behaviors in the system, is studied using the largest Lyapunov exponent, and the Wolf method is used to predict the evolution of the traffic in a local area network by both Dot and Interval predictions, and a reliable result is obtained by the presented method. As the conclusion, the results show that the largest Lyapunov exponent can be used to describe the sensitivity of the trajectory in the reconstructed phase space to the initial values. Moreover, Dot Prediction can effectively predict the flow burst. The numerical simulation also shows that the presented method is feasible and efficient for predicting the complex dynamic behaviors in LAN traffic, especially for congestion and attack in networks, which are the main two complex phenomena behaving as chaos in networks. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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Open AccessArticle

Increment Entropy as a Measure of Complexity for Time Series

by Xiaofeng Liu, Aimin Jiang, Ning Xu and Jianru Xue

Entropy 2016, 18(1), 22; https://doi.org/10.3390/e18010022 - 8 Jan 2016

Cited by 51 | Viewed by 9624 | Correction

Abstract

Entropy has been a common index to quantify the complexity of time series in a variety of fields. Here, we introduce an increment entropy to measure the complexity of time series in which each increment is mapped onto a word of two letters, [...] Read more.

Entropy has been a common index to quantify the complexity of time series in a variety of fields. Here, we introduce an increment entropy to measure the complexity of time series in which each increment is mapped onto a word of two letters, one corresponding to the sign and the other corresponding to the magnitude. Increment entropy (IncrEn) is defined as the Shannon entropy of the words. Simulations on synthetic data and tests on epileptic electroencephalogram (EEG) signals demonstrate its ability of detecting abrupt changes, regardless of the energetic (e.g., spikes or bursts) or structural changes. The computation of IncrEn does not make any assumption on time series, and it can be applicable to arbitrary real-world data. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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647 KiB

Open AccessArticle

Cloud Entropy Management System Involving a Fractional Power

by Rabha W. Ibrahim, Hamid A. Jalab and Abdullah Gani

Entropy 2016, 18(1), 14; https://doi.org/10.3390/e18010014 - 29 Dec 2015

Cited by 12 | Viewed by 4975

Abstract

Cloud computing (CC) capacities deliver high quality, connected with demand services and service-oriented construction. Nevertheless, a cloud service (CS) is normally derived from numerous stages of facilities and concert features, which determine the value of the cloud service. Therefore, it is problematic for [...] Read more.

Cloud computing (CC) capacities deliver high quality, connected with demand services and service-oriented construction. Nevertheless, a cloud service (CS) is normally derived from numerous stages of facilities and concert features, which determine the value of the cloud service. Therefore, it is problematic for the users to estimate these cloud services and select them to appropriate their requirements. In this study, a new algorithm is carried out for a multi-agent system (MAS) based on fractional power. The study depends on a fractional difference equation of type two point boundary value problem (BVP) based on the fractional entropy. We discuss the existence of solutions for the system as well as the stability, utilizing the Hadamard well-posed problem. Experimental results show that the proposed method demonstrates stability and performance. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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6403 KiB

Open AccessArticle

Complexity Analysis and DSP Implementation of the Fractional-Order Lorenz Hyperchaotic System

by Shaobo He, Kehui Sun and Huihai Wang

Entropy 2015, 17(12), 8299-8311; https://doi.org/10.3390/e17127882 - 18 Dec 2015

Cited by 180 | Viewed by 8309

Abstract

The fractional-order hyperchaotic Lorenz system is solved as a discrete map by applying the Adomian decomposition method (ADM). Lyapunov Characteristic Exponents (LCEs) of this system are calculated according to this deduced discrete map. Complexity of this system versus parameters are analyzed by LCEs, [...] Read more.

The fractional-order hyperchaotic Lorenz system is solved as a discrete map by applying the Adomian decomposition method (ADM). Lyapunov Characteristic Exponents (LCEs) of this system are calculated according to this deduced discrete map. Complexity of this system versus parameters are analyzed by LCEs, bifurcation diagrams, phase portraits, complexity algorithms. Results show that this system has rich dynamical behaviors. Chaos and hyperchaos can be generated by decreasing fractional order q in this system. It also shows that the system is more complex when q takes smaller values. SE and C 0 complexity algorithms provide a parameter choice criteria for practice applications of fractional-order chaotic systems. The fractional-order system is implemented by digital signal processor (DSP), and a pseudo-random bit generator is designed based on the implemented system, which passes the NIST test successfully. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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4030 KiB

Open AccessArticle

Identify the Rotating Stall in Centrifugal Compressors by Fractal Dimension in Reconstructed Phase Space

by Le Wang, Jiazhong Zhang and Wenfan Zhang

Entropy 2015, 17(12), 7888-7899; https://doi.org/10.3390/e17127848 - 30 Nov 2015

Cited by 13 | Viewed by 6409

Abstract

Based on phase space reconstruction and fractal dynamics in nonlinear dynamics, a method is proposed to extract and analyze the dynamics of the rotating stall in the impeller of centrifugal compressor, and some numerical examples are given to verify the results as well. [...] Read more.

Based on phase space reconstruction and fractal dynamics in nonlinear dynamics, a method is proposed to extract and analyze the dynamics of the rotating stall in the impeller of centrifugal compressor, and some numerical examples are given to verify the results as well. First, the rotating stall of an existing low speed centrifugal compressor (LSCC) is numerically simulated, and the time series of pressure in the rotating stall is obtained at various locations near the impeller outlet. Then, the phase space reconstruction is applied to these pressure time series, and a low-dimensional dynamical system, which the dynamics properties are included in, is reconstructed. In phase space reconstruction, C–C method is used to obtain the key parameters, such as time delay and the embedding dimension of the reconstructed phase space. Further, the fractal characteristics of the rotating stall are analyzed in detail, and the fractal dimensions are given for some examples to measure the complexity of the flow in the post-rotating stall. The results show that the fractal structures could reveal the intrinsic dynamics of the rotating stall flow and could be considered as a characteristic to identify the rotating stall. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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1800 KiB

Open AccessArticle

A Memristor-Based Complex Lorenz System and Its Modified Projective Synchronization

by Shibing Wang, Xingyuan Wang and Yufei Zhou

Entropy 2015, 17(11), 7628-7644; https://doi.org/10.3390/e17117628 - 5 Nov 2015

Cited by 29 | Viewed by 8256

Abstract

The aim of this paper is to introduce and investigate a novel complex Lorenz system with a flux-controlled memristor, and to realize its synchronization. The system has an infinite number of stable and unstable equilibrium points, and can generate abundant dynamical behaviors with [...] Read more.

The aim of this paper is to introduce and investigate a novel complex Lorenz system with a flux-controlled memristor, and to realize its synchronization. The system has an infinite number of stable and unstable equilibrium points, and can generate abundant dynamical behaviors with different parameters and initial conditions, such as limit cycle, torus, chaos, transient phenomena, etc., which are explored by means of time-domain waveforms, phase portraits, bifurcation diagrams, and Lyapunov exponents. Furthermore, an active controller is designed to achieve modified projective synchronization (MPS) of this system based on Lyapunov stability theory. The corresponding numerical simulations agree well with the theoretical analysis, and demonstrate that the response system is asymptotically synchronized with the drive system within a short time. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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831 KiB

Open AccessArticle

Characterization of Complex Fractionated Atrial Electrograms by Sample Entropy: An International Multi-Center Study

by Eva Cirugeda–Roldán, Daniel Novak, Vaclav Kremen, David Cuesta–Frau, Matthias Keller, Armin Luik and Martina Srutova

Entropy 2015, 17(11), 7493-7509; https://doi.org/10.3390/e17117493 - 28 Oct 2015

Cited by 16 | Viewed by 7197

Abstract

Atrial fibrillation (AF) is the most commonly clinically-encountered arrhythmia. Catheter ablation of AF is mainly based on trigger elimination and modification of the AF substrate. Substrate mapping ablation of complex fractionated atrial electrograms (CFAEs) has emerged to be a promising technique. To improve [...] Read more.

Atrial fibrillation (AF) is the most commonly clinically-encountered arrhythmia. Catheter ablation of AF is mainly based on trigger elimination and modification of the AF substrate. Substrate mapping ablation of complex fractionated atrial electrograms (CFAEs) has emerged to be a promising technique. To improve substrate mapping based on CFAE analysis, automatic detection algorithms need to be developed in order to simplify and accelerate the ablation procedures. According to the latest studies, the level of fractionation has been shown to be promisingly well estimated from CFAE measured during radio frequency (RF) ablation of AF. The nature of CFAE is generally nonlinear and nonstationary, so the use of complexity measures is considered to be the appropriate technique for the analysis of AF records. This work proposes the use of sample entropy (SampEn), not only as a way to discern between non-fractionated and fractionated atrial electrograms (A-EGM), Entropy 2015, 17 7494 but also as a tool for characterizing the degree of A-EGM regularity, which is linked to changes in the AF substrate and to heart tissue damage. The use of SampEn combined with a blind parameter estimation optimization process enables the classification between CFAE and non-CFAE with statistical significance (p < 0:001), 0.89 area under the ROC, 86% specificity and 77% sensitivity over a mixed database of A-EGM combined from two independent CFAE signal databases, recorded during RF ablation of AF in two EU countries (542 signals in total). On the basis of the results obtained in this study, it can be suggested that the use of SampEn is suitable for real-time support during navigation of RF ablation of AF, as only 1.5 seconds of signal segments need to be analyzed. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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388 KiB

Open AccessArticle

Adaptive Synchronization for a Class of Uncertain Fractional-Order Neural Networks

by Heng Liu, Shenggang Li, Hongxing Wang, Yuhong Huo and Junhai Luo

Entropy 2015, 17(10), 7185-7200; https://doi.org/10.3390/e17107185 - 22 Oct 2015

Cited by 59 | Viewed by 5803

Abstract

In this paper, synchronization for a class of uncertain fractional-order neural networks subject to external disturbances and disturbed system parameters is studied. Based on the fractional-order extension of the Lyapunov stability criterion, an adaptive synchronization controller is designed, and fractional-order adaptation law is [...] Read more.

In this paper, synchronization for a class of uncertain fractional-order neural networks subject to external disturbances and disturbed system parameters is studied. Based on the fractional-order extension of the Lyapunov stability criterion, an adaptive synchronization controller is designed, and fractional-order adaptation law is proposed to update the controller parameter online. The proposed controller can guarantee that the synchronization errors between two uncertain fractional-order neural networks converge to zero asymptotically. By using some proposed lemmas, the quadratic Lyapunov functions are employed in the stability analysis. Finally, numerical simulations are presented to confirm the effectiveness of the proposed method. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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2927 KiB

Open AccessArticle

A Novel Image Encryption Algorithm Based on DNA Encoding and Spatiotemporal Chaos

by Chunyan Song and Yulong Qiao

Entropy 2015, 17(10), 6954-6968; https://doi.org/10.3390/e17106954 - 16 Oct 2015

Cited by 87 | Viewed by 8646

Abstract

DNA computing based image encryption is a new, promising field. In this paper, we propose a novel image encryption scheme based on DNA encoding and spatiotemporal chaos. In particular, after the plain image is primarily diffused with the bitwise Exclusive-OR operation, the DNA [...] Read more.

DNA computing based image encryption is a new, promising field. In this paper, we propose a novel image encryption scheme based on DNA encoding and spatiotemporal chaos. In particular, after the plain image is primarily diffused with the bitwise Exclusive-OR operation, the DNA mapping rule is introduced to encode the diffused image. In order to enhance the encryption, the spatiotemporal chaotic system is used to confuse the rows and columns of the DNA encoded image. The experiments demonstrate that the proposed encryption algorithm is of high key sensitivity and large key space, and it can resist brute-force attack, entropy attack, differential attack, chosen-plaintext attack, known-plaintext attack and statistical attack. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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907 KiB

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Approximate Analytical Solutions of Time Fractional Whitham–Broer–Kaup Equations by a Residual Power Series Method

by Linjun Wang and Xumei Chen

Entropy 2015, 17(9), 6519-6533; https://doi.org/10.3390/e17096519 - 23 Sep 2015

Cited by 64 | Viewed by 5584

Abstract

In this paper, a new analytic iterative technique, called the residual power series method (RPSM), is applied to time fractional Whitham–Broer–Kaup equations. The explicit approximate traveling solutions are obtained by using this method. The efficiency and accuracy of the present method is demonstrated [...] Read more.

In this paper, a new analytic iterative technique, called the residual power series method (RPSM), is applied to time fractional Whitham–Broer–Kaup equations. The explicit approximate traveling solutions are obtained by using this method. The efficiency and accuracy of the present method is demonstrated by two aspects. One is analyzing the approximate solutions graphically. The other is comparing the results with those of the Adomian decomposition method (ADM), the variational iteration method (VIM) and the optimal homotopy asymptotic method (OHAM). Illustrative examples reveal that the present technique outperforms the aforementioned methods and can be used as an alternative for solving fractional equations. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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Open AccessArticle

Modeling of a Mass-Spring-Damper System by Fractional Derivatives with and without a Singular Kernel

by José Francisco Gómez-Aguilar, Huitzilin Yépez-Martínez, Celia Calderón-Ramón, Ines Cruz-Orduña, Ricardo Fabricio Escobar-Jiménez and Victor Hugo Olivares-Peregrino

Entropy 2015, 17(9), 6289-6303; https://doi.org/10.3390/e17096289 - 10 Sep 2015

Cited by 142 | Viewed by 35874

Abstract

In this paper, the fractional equations of the mass-spring-damper system with Caputo and Caputo–Fabrizio derivatives are presented. The physical units of the system are preserved by introducing an auxiliary parameter σ. The input of the resulting equations is a constant and periodic source; [...] Read more.

In this paper, the fractional equations of the mass-spring-damper system with Caputo and Caputo–Fabrizio derivatives are presented. The physical units of the system are preserved by introducing an auxiliary parameter σ. The input of the resulting equations is a constant and periodic source; for the Caputo case, we obtain the analytical solution, and the resulting equations are given in terms of the Mittag–Leffler function; for the Caputo–Fabrizio approach, the numerical solutions are obtained by the numerical Laplace transform algorithm. Our results show that the mechanical components exhibit viscoelastic behaviors producing temporal fractality at different scales and demonstrate the existence of Entropy 2015, 17 6290 material heterogeneities in the mechanical components. The Markovian nature of the model is recovered when the order of the fractional derivatives is equal to one. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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Open AccessArticle

Fractional State Space Analysis of Economic Systems

by J. A. Tenreiro Machado, Maria Eugénia Mata and António M. Lopes

Entropy 2015, 17(8), 5402-5421; https://doi.org/10.3390/e17085402 - 29 Jul 2015

Cited by 78 | Viewed by 7207

Abstract

This paper examines modern economic growth according to the multidimensional scaling (MDS) method and state space portrait (SSP) analysis. Electing GDP per capita as the main indicator for economic growth and prosperity, the long-run perspective from 1870 to 2010 identifies the main similarities [...] Read more.

This paper examines modern economic growth according to the multidimensional scaling (MDS) method and state space portrait (SSP) analysis. Electing GDP per capita as the main indicator for economic growth and prosperity, the long-run perspective from 1870 to 2010 identifies the main similarities among 34 world partners’ modern economic growth and exemplifies the historical waving mechanics of the largest world economy, the USA. MDS reveals two main clusters among the European countries and their old offshore territories, and SSP identifies the Great Depression as a mild challenge to the American global performance, when compared to the Second World War and the 2008 crisis. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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872 KiB

Open AccessArticle

Fractional Differential Texture Descriptors Based on the Machado Entropy for Image Splicing Detection

by Rabha W. Ibrahim, Zahra Moghaddasi, Hamid A. Jalab and Rafidah Md Noor

Entropy 2015, 17(7), 4775-4785; https://doi.org/10.3390/e17074775 - 8 Jul 2015

Cited by 31 | Viewed by 5529

Abstract

Image splicing is a common operation in image forgery. Different techniques of image splicing detection have been utilized to regain people’s trust. This study introduces a texture enhancement technique involving the use of fractional differential masks based on the Machado entropy. The masks [...] Read more.

Image splicing is a common operation in image forgery. Different techniques of image splicing detection have been utilized to regain people’s trust. This study introduces a texture enhancement technique involving the use of fractional differential masks based on the Machado entropy. The masks slide over the tampered image, and each pixel of the tampered image is convolved with the fractional mask weight window on eight directions. Consequently, the fractional differential texture descriptors are extracted using the gray-level co-occurrence matrix for image splicing detection. The support vector machine is used as a classifier that distinguishes between authentic and spliced images. Results prove that the achieved improvements of the proposed algorithm are compatible with other splicing detection methods. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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436 KiB

Open AccessArticle

H_∞ Control for Markov Jump Systems with Nonlinear Noise Intensity Function and Uncertain Transition Rates

by Xiaonian Wang and Yafeng Guo

Entropy 2015, 17(7), 4762-4774; https://doi.org/10.3390/e17074762 - 6 Jul 2015

Cited by 2 | Viewed by 4016

Abstract

The problem of robust H_∞ control is investigated for Markov jump systems with nonlinear noise intensity function and uncertain transition rates. A robust H_∞ performance criterion is developed for the given systems for the first time. Based on the developed performance [...] Read more.

The problem of robust H_∞ control is investigated for Markov jump systems with nonlinear noise intensity function and uncertain transition rates. A robust H_∞ performance criterion is developed for the given systems for the first time. Based on the developed performance criterion, the desired H_∞ state-feedback controller is also designed, which guarantees the robust H_∞ performance of the closed-loop system. All the conditions are in terms of linear matrix inequalities (LMIs), and hence they can be readily solved by any LMI solver. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed methods. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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729 KiB

Open AccessArticle

Generalized Boundary Conditions for the Time-Fractional Advection Diffusion Equation

by Yuriy Povstenko

Entropy 2015, 17(6), 4028-4039; https://doi.org/10.3390/e17064028 - 12 Jun 2015

Cited by 22 | Viewed by 5512

Abstract

The different kinds of boundary conditions for standard and fractional diffusion and advection diffusion equations are analyzed. Near the interface between two phases there arises a transition region which state differs from the state of contacting media owing to the different material particle [...] Read more.

The different kinds of boundary conditions for standard and fractional diffusion and advection diffusion equations are analyzed. Near the interface between two phases there arises a transition region which state differs from the state of contacting media owing to the different material particle interaction conditions. Particular emphasis has been placed on the conditions of nonperfect diffusive contact for the time-fractional advection diffusion equation. When the reduced characteristics of the interfacial region are equal to zero, the conditions of perfect contact are obtained as a particular case. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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Existence of Ulam Stability for Iterative Fractional Differential Equations Based on Fractional Entropy

by Rabha W. Ibrahim and Hamid A. Jalab

Entropy 2015, 17(5), 3172-3181; https://doi.org/10.3390/e17053172 - 13 May 2015

Cited by 34 | Viewed by 4887

Abstract

In this study, we introduce conditions for the existence of solutions for an iterative functional differential equation of fractional order. We prove that the solutions of the above class of fractional differential equations are bounded by Tsallis entropy. The method depends on the [...] Read more.

In this study, we introduce conditions for the existence of solutions for an iterative functional differential equation of fractional order. We prove that the solutions of the above class of fractional differential equations are bounded by Tsallis entropy. The method depends on the concept of Hyers-Ulam stability. The arbitrary order is suggested in the sense of Riemann-Liouville calculus. Full article

(This article belongs to the Special Issue Complex and Fractional Dynamics)

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