385 results
Search Results
52. A higher order numerical scheme for solving fractional Bagley‐Torvik equation
- Author
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Patricia J. Y. Wong, Qinxu Ding, and School of Electrical and Electronic Engineering
- Subjects
Discrete Spline ,Fractional Bagley-Torvik Equation ,Order (business) ,General Mathematics ,Scheme (mathematics) ,Electrical and electronic engineering [Engineering] ,General Engineering ,Applied mathematics ,Mathematics - Abstract
In this paper, we develop a higher order numerical method for the fractional Bagley-Torvik equation. The main tools used include a new fourth-order approximation for the fractional derivative based on the weighted shifted Grünwald-Letnikov difference operator and a discrete cubic spline approach. We show that the theoretical convergence order improves those of previous work. Five examples are further presented to illustrate the efficiency of our method and to compare with other methods in the literature.
- Published
- 2021
53. Goodness‐of‐fit measures based on the Mellin transform for beta generalized lifetime data
- Author
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Abraão D. C. Nascimento, Renato J. Cintra, and Josimar Mendes de Vasconcelos
- Subjects
Mellin transform ,Class (set theory) ,Goodness of fit ,Heavy-tailed distribution ,General Mathematics ,Model selection ,General Engineering ,Order (ring theory) ,Applied mathematics ,Ellipse ,Statistic ,Mathematics - Abstract
In recent years various probability models have been proposed for describing lifetime data. Increasing model flexibility is often sought as a means to better describe asymmetric and heavy tail distributions. Such extensions were pioneered by the beta-G family. However, efficient goodness-of-fit (GoF) measures for the beta-G distributions are sought. In this paper, we combine probability weighted moments (PWMs) and the Mellin transform (MT) in order to furnish new qualitative and quantitative GoF tools for model selection within the beta-G class. We derive PWMs for the Fr\’{e}chet and Kumaraswamy distributions; and we provide expressions for the MT, and for the log-cumulants (LC) of the beta-Weibull, beta-Fr\’{e}chet, beta-Kumaraswamy, and beta-log-logistic distributions. Subsequently, we construct LC diagrams and, based on the Hotelling’s $T^2$ statistic, we derive confidence ellipses for the LCs. Finally, the proposed GoF measures are applied on five real data sets in order to demonstrate their applicability.
- Published
- 2021
54. A remark on the well‐posedness of the classical Green–Naghdi system
- Author
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Bashar Khorbatly
- Subjects
Operator (computer programming) ,General Mathematics ,Norm (mathematics) ,General Engineering ,Applied mathematics ,Natural energy ,Energy (signal processing) ,Well posedness ,Mathematics - Abstract
The aim of this paper is to give an alternative technique for the derivation of a prior energy estimate. Consequently, this allows to define a natural energy norm of the long-term well-posedness result established by S. Israwi in [2] but for the original system, in which the partial operator ∇× is not involved.
- Published
- 2021
55. Higher order stable schemes for stochastic convection–reaction–diffusion equations driven by additive Wiener noise
- Author
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Jean Daniel Mukam and Antoine Tambue
- Subjects
General Mathematics ,Numerical analysis ,finite element method ,General Engineering ,White noise ,Exponential integrator ,VDP::Matematikk og Naturvitenskap: 400::Matematikk: 410 ,Noise (electronics) ,Finite element method ,strong convergence ,Stochastic partial differential equation ,Galerkin projection method ,Nonlinear system ,symbols.namesake ,Wiener process ,symbols ,Applied mathematics ,stochastic convection–reaction–diffusion equations ,additive noise ,exponential integrators ,Mathematics - Abstract
In this paper, we investigate the numerical approximation of stochastic convection-reaction-diffusion equations using two explicit exponential integrators. The stochastic partial differential equation (SPDE) is driven by additive Wiener process. The approximation in space is done via a combination of the standard finite element method and the Galerkin projection method. Using the linear functional of the noise, we construct two accelerated numerical methods, which achieve higher convergence orders. In particular, we achieve convergence rates approximately $1$ for trace class noise and $\frac{1}{2}$ for space-time white noise. These convergences orders are obtained under less regularities assumptions on the nonlinear drift function than those used in the literature for stochastic reaction-diffusion equations. Numerical experiments to illustrate our theoretical results are provided
- Published
- 2021
56. On asymptotically statistical equivalent functions on time scales
- Author
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Selma Altundağ and Bayram Sözbir
- Subjects
Modulo operation ,General Mathematics ,General Engineering ,Applied mathematics ,Statistical convergence ,Mathematics - Abstract
In this paper, we introduce the concepts of asymptotically f-statistical equivalence, asymptotically f-lacunary statistical equivalence, and strong asymptotically f-lacunary equivalence for non-negative two delta measurable real-valued functions defined on time scales with the aid of modulus function f. Furthermore, the relationships between these new concepts are investigated. We also present some inclusion theorems.
- Published
- 2021
57. An iterative method for optimal control of bilateral free boundaries problem
- Author
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Youness El Yazidi and Abdellatif Ellabib
- Subjects
Computer science ,Iterative method ,General Mathematics ,010102 general mathematics ,General Engineering ,Inverse problem ,Optimal control ,01 natural sciences ,Regularization (mathematics) ,Finite element method ,010101 applied mathematics ,Robustness (computer science) ,Conjugate gradient method ,Applied mathematics ,Gravitational singularity ,Shape gradient ,Shape optimization ,0101 mathematics ,Mathematics - Abstract
The aim of this paper is to construct a numerical scheme for solving a class of bilateral free boundaries problem. First, using a shape functional and some regularization terms, an optimal control problem is formulated, in addition, we prove its solution existence's. The first optimality conditions and the shape gradient are computed. the proposed numerical scheme is a genetic algorithm guided conjugate gradient combined with the finite element method, at each mesh regeneration, we perform a mesh refinement in order to avoid any domain singularities. Some numerical examples are shown to demonstrate the validity of the theoretical results, and to prove the robustness of the proposed scheme.
- Published
- 2021
58. Mathematical models for the improvement of detection techniques of industrial noise sources from acoustic images
- Author
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Gianluca Vinti, Giorgio Baldinelli, Francesco Bianchi, Francesco D'Alessandro, Marco Seracini, Danilo Costarelli, Francesco Asdrubali, Flavio Scrucca, Asdrubali, Francesco, Baldinelli, Giorgio, Bianchi, Francesco, Costarelli, Danilo, D'Alessandro, Francesco, Scrucca, Flavio, Seracini, Marco, and Vinti, Gianluca
- Subjects
Beamforming ,acoustic images, applied mathematics, beamforming, image reconstruction, industrial noise, sam-pling Kantorovich algorithm ,Mathematical model ,business.industry ,General Mathematics ,industrial noise ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,General Engineering ,acoustic images ,Industrial noise ,Iterative reconstruction ,image reconstruction ,sampling Kantorovich algorithm ,beamforming ,applied mathematics ,Computer vision ,Artificial intelligence ,business ,Mathematics - Abstract
In this paper, a procedure for the detection of the sources of industrial noise and the evaluation of their distances is introduced. The above method is based on the analysis of acoustic and optical data recorded by an acoustic camera. In order to improve the resolution of the data, interpolation and quasi interpolation algorithms for digital data processing have been used, such as the bilinear, bicubic, and sampling Kantorovich (SK). The experimental tests show that the SK algorithm allows to perform the above task more accurately than the other considered methods.
- Published
- 2021
59. A generalized fractional ( q , h )–Gronwall inequality and its applications to nonlinear fractional delay ( q , h )–difference systems
- Author
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Feifei Du and Baoguo Jia
- Subjects
010101 applied mathematics ,Nonlinear system ,Uniqueness theorem for Poisson's equation ,Stability criterion ,General Mathematics ,Gronwall's inequality ,010102 general mathematics ,General Engineering ,Applied mathematics ,Uniqueness ,0101 mathematics ,01 natural sciences ,Mathematics - Abstract
In this paper, a generalized fractional $(q,h)$-Gronwall inequality is investigated. Based on this inequality, we derive the uniqueness theorem and the finite-time stability criterion of nonlinear fractional delay $(q,h)$-difference systems. Several examples are given to illustrate our theoretical result.
- Published
- 2021
60. Existence and stability for a nonlinear hybrid differential equation of fractional order via regular Mittag–Leffler kernel
- Author
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Ibrahim Slimane, Juan J. Nieto, Thabet Abdeljawad, and Zoubir Dahmani
- Subjects
Mathematics::Functional Analysis ,Nonlinear system ,Differential equation ,General Mathematics ,Kernel (statistics) ,Mathematics::Classical Analysis and ODEs ,General Engineering ,Order (group theory) ,Applied mathematics ,Contraction (operator theory) ,Stability (probability) ,Mathematics ,Fractional calculus - Abstract
This paper deals with a nonlinear hybrid differential equation written using a fractional derivative with a Mittag–Leffler kernel. Firstly, we establish the existence of solutions to the studied problem by using the Banach contraction theorem. Then, by means of the Dhage fixed-point principle, we discuss the existence of mild solutions. Finally, we study the Ulam–Hyers stability of the introduced fractional hybrid problem.
- Published
- 2021
61. Nonoscillation of half‐linear dynamic equations on time scales
- Author
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Michal Veselý, Petr Hasil, Michal Pospíšil, and Jozef Kiselak
- Subjects
Ideal (set theory) ,Oscillation ,General Mathematics ,010102 general mathematics ,General Engineering ,Qualitative theory ,01 natural sciences ,Domain (mathematical analysis) ,010101 applied mathematics ,Riccati equation ,Applied mathematics ,0101 mathematics ,Dynamic equation ,Linear equation ,Mathematics - Abstract
The research contained in this paper belongs to the qualitative theory of dynamic equations on time scales. Via the detailed analysis of solutions of the associated Riccati equation and an advanced averaging technique, we provide the description of domain of nonoscillation of very general equations. The results are formulated and proved for half-linear equations (i.e., equations connected to PDEs with one dimensional p-Laplacian) on time scales. Nevertheless, we obtain new results also for linear difference equations. Moreover, the combination of the presented results with previous ones shows that many useful equations are conditionally oscillatory. Such equations are ideal as testing and comparison equations in real-world models which are beyond capabilities of known oscillation and nonoscillation criteria often.
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- 2021
62. Minimal-energy splines: I. Plane curves with angle constraints
- Author
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Weimin Han and Emery D. Jou
- Subjects
Box spline ,Plane curve ,General Mathematics ,General Engineering ,Geometry ,Mathematics::Numerical Analysis ,symbols.namesake ,Spline (mathematics) ,Smoothing spline ,Computer Science::Graphics ,Lagrange multiplier ,symbols ,Applied mathematics ,Spline interpolation ,Thin plate spline ,Mathematics - Abstract
This is the first in a series of papers on minimal-energy splines. The paper is devoted to plane minimal-energy splines with angle constraints. We first consider minimal-energy spline segments, then general minimal-energy spline curves. We formulate problems for minimal-energy spline segments and curves, prove the existence of solutions, justify the Lagrange multiplier rules, and obtain some nice properties (e.g., the infinite smoothness). Finally, we report our computational experience on minimal-energy splines.
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- 1990
63. The gradient descent method from the perspective of fractional calculus
- Author
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Joel A. Rosenfeld and Pham Viet Hai
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General Mathematics ,010102 general mathematics ,General Engineering ,Order (ring theory) ,Unconstrained optimization ,01 natural sciences ,Fractional calculus ,010101 applied mathematics ,Perspective (geometry) ,Optimization and Control (math.OC) ,Convergence (routing) ,FOS: Mathematics ,Applied mathematics ,0101 mathematics ,Gradient descent ,Mathematics - Optimization and Control ,Gradient method ,Mathematics - Abstract
Motivated by gradient methods in optimization theory, we give methods based on $\psi$-fractional derivatives of order $\alpha$ in order to solve unconstrained optimization problems. The convergence of these methods is analyzed in detail. This paper also presents an Adams-Bashforth-Moulton (ABM) method for the estimation of solutions to equations involving $\psi$-fractional derivatives. Numerical examples using the ABM method show that the fractional order $\alpha$ and weight $\psi$ are tunable parameters, which can be helpful for improving the performance of gradient descent methods., Comment: 27 pages
- Published
- 2020
64. Translation‐invariant generalized P ‐adic Gibbs measures for the Ising model on Cayley trees
- Author
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Otabek Khakimov and Farrukh Mukhamedov
- Subjects
Phase transition ,General Mathematics ,010102 general mathematics ,General Engineering ,Fixed point ,Invariant (physics) ,01 natural sciences ,010101 applied mathematics ,Singularity ,Probability theory ,Physical phenomena ,Applied mathematics ,Ising model ,0101 mathematics ,Mathematics ,p-adic number - Abstract
Main aim of the present paper is explore certain physical phenomena by means of $p$-adic probability theory. To overcome this study, we deal with a more general setting to define $p$-adic Gibbs measures. For the sake of simplicity of explanations, we restrict ourselves to the Ising model on the Cayley tree, since such a model has broad theoretical and practical applications. To study $p$-adic quasi Gibbs measures, we reduce the problem to the description of the fixed points of the Ising-Potts mapping. Finding fixed points is not an easy job as in the real setting. Furthermore, the phase transition for the model is established. In the real case, the phase transition yields the the singularity of the limiting Gibbs measures. However, we show that the $p$-adic quasi Gibbs measures do not exhibit the mentioned type of singularity, such kind of phenomena is called strong phase transition. Finally, we deal with the solvability and the number of solutions of ceratin $p$-adic equation depending on several parameters. Such a description allows us to find all possible translation-invariant $p$a-adic quasi Gibbs measures.
- Published
- 2020
65. Generalized approximate boundary synchronization for a coupled system of wave equations
- Author
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Yanyan Wang
- Subjects
General Mathematics ,010102 general mathematics ,General Engineering ,Boundary (topology) ,State (functional analysis) ,Kalman filter ,Wave equation ,01 natural sciences ,Dirichlet distribution ,010101 applied mathematics ,Matrix (mathematics) ,symbols.namesake ,Synchronization (computer science) ,symbols ,Applied mathematics ,0101 mathematics ,Mathematics - Abstract
In this paper, we consider the generalized approximate boundary synchronization for a coupled system of wave equations with Dirichlet boundary controls. We analyse the relationship between the generalized approximate boundary synchronization and the generalized exact boundary synchronization, give a sufficient condition to realize the generalized approximate boundary synchronization and a necessary condition in terms of Kalman’s matrix, and show the meaning of the number of total controls. Besides, by the generalized synchronization decomposition, we define the generalized approximately synchronizable state, and obtain its properties and a sufficient condition for it to be independent of applied boundary controls.
- Published
- 2020
66. Consensus of the Hegselmann–Krause opinion formation model with time delay
- Author
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Cristina Pignotti, Alessandro Paolucci, and Young-Pil Choi
- Subjects
Particle system ,Partial differential equation ,Continuum (topology) ,General Mathematics ,media_common.quotation_subject ,010102 general mathematics ,General Engineering ,Infinity ,01 natural sciences ,Exponential function ,010101 applied mathematics ,Mathematics - Analysis of PDEs ,FOS: Mathematics ,Applied mathematics ,Uniqueness ,Limit (mathematics) ,0101 mathematics ,Analysis of PDEs (math.AP) ,Mathematics ,media_common ,Opinion formation - Abstract
In this paper, we study Hegselmann-Krause models with a time-variable time delay. Under appropriate assumptions, we show the exponential asymptotic consensus when the time delay satisfies a suitable smallness assumption. Our main strategies for this are based on Lyapunov functional approach and careful estimates on the trajectories. We then study the mean-field limit from the many-individual Hegselmann-Krause equation to the continuity-type partial differential equation as the number N of individuals goes to infinity. For the limiting equation, we prove global-in-time existence and uniqueness of measure-valued solutions. We also use the fact that constants appearing in the consensus estimates for the particle system are independent of N to extend the exponential consensus result to the continuum model. Finally, some numerical tests are illustrated.
- Published
- 2020
67. On Bernoulli series approximation for the matrix cosine
- Author
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Jose M. Alonso, Emilio Defez, Javier Ibáñez, and Pedro Alonso-Jordá
- Subjects
Matrix exponential and similar functions of matrices ,Matrix (mathematics) ,Bernoulli's principle ,Polynomials and matrices ,General Mathematics ,CIENCIAS DE LA COMPUTACION E INTELIGENCIA ARTIFICIAL ,General Engineering ,Applied mathematics ,Trigonometric functions ,Series approximation ,MATEMATICA APLICADA ,Mathematics - Abstract
[EN] This paper presents a new series expansion based on Bernoulli matrix polynomials to approximate the matrix cosine function. An approximation based on this series is not a straightforward exercise since there exist different options to implement such a solution. We dive into these options and include a thorough comparative of performance and accuracy in the experimental results section that shows benefits and downsides of each one. Also, a comparison with the Pade approximation is included. The algorithms have been implemented in MATLAB and in CUDA for NVIDIA GPUs., Spanish Ministerio de Economia y Competitividad and European Regional Development Fund, Grant/Award Number: TIN2017-89314-P; Universitat Politecnica de Valencia, Grant/Award Number: SP20180016
- Published
- 2020
68. Structured singular value of implicit systems
- Author
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George Halikias, Nicos Karcanias, and Olga Limantseva
- Subjects
Matrix (mathematics) ,Singular value ,Systems theory ,General Mathematics ,General Engineering ,Stability (learning theory) ,Structure (category theory) ,Scalar (physics) ,Applied mathematics ,Algebraic number ,Robust control ,QA ,Mathematics - Abstract
Implicit systems provide a general framework in which many important properties of dynamic systems can be studied. Implicit systems are especially relevant to behavioural systems theory, the analysis and synthesis of complex interconnected systems, systems identification and robust control. By incorporating algebraic constraints, implicit models provide additional versatility relative to the standard input–output framework. Problems of robust stability in implicit systems lead in a natural way to non‐standard structured singular value (μ) formulations. In this note, it is shown that for a class of uncertainty structures involving repeated scalar parameters, these problems reduce to a standard μ problem which is well studied and for the solution of which several numerical algorithms are available. Our results are based on a matrix dilation technique and the redefinition of the uncertainty structure of the transformed problem. The main results of the paper are illustrated with a numerical example.
- Published
- 2020
69. Analysis and numerical simulation of novel coronavirus (COVID‐19) model with Mittag‐Leffler Kernel
- Author
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V. Padmavathi, Amit Prakash, K. Alagesan, and Nanjundan Magesh
- Subjects
Current (mathematics) ,Coronavirus disease 2019 (COVID-19) ,Computer simulation ,General Mathematics ,Homotopy ,010102 general mathematics ,General Engineering ,01 natural sciences ,Fractional operator ,Nonlinear differential equations ,Fractional calculus ,010101 applied mathematics ,Kernel (statistics) ,Applied mathematics ,0101 mathematics ,Mathematics - Abstract
Every now and then, there has been natural or man-made calamities Such adversities instigate various institutions to find solutions for them The current study attempts to explore the disaster caused by the micro enemy called coronavirus for the past few months and aims at finding the solution for the system of nonlinear ordinary differential equations to which q?homotopy analysis transform method (q?HATM) has been applied to arrive at effective results In this paper, there are eight nonlinear ordinary differential equations considered and to solve them the advanced fractional operator Atangana-Baleanu (AB) fractional derivative has been applied to produce better understanding The outcomes have been presented in terms of plots Ultimately, the present study assists in examining the real-world models and aids in predicting their behavior corresponding to the parameters considered in the models
- Published
- 2020
70. A critical Kirchhoff‐type problem driven by ap (·)‐fractional Laplace operator with variables (·) ‐order
- Author
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Alessio Fiscella, Tianqing An, Jiabin Zuo, Zuo, J, An, T, and Fiscella, A
- Subjects
Kirchhoff coefficient ,variable exponent ,Variable exponent ,Kirchhoff type ,General Mathematics ,p(·)-fractional Laplacian ,General Engineering ,Applied mathematics ,Order (group theory) ,critical nonlinearity ,Laplace operator ,Mathematics ,Variable (mathematics) - Abstract
The paper deals with the following Kirchhoff-type problem (Formula presented.) where M models a Kirchhoff coefficient, (Formula presented.) is a variable s(·)-order p(·)-fractional Laplace operator, with (Formula presented.) and (Formula presented.). Here, (Formula presented.) is a bounded smooth domain with N > p(x, y)s(x, y) for any (Formula presented.), μ is a positive parameter, g is a continuous and subcritical function, while variable exponent r(x) could be close to the critical exponent (Formula presented.), given with (Formula presented.) and (Formula presented.) for (Formula presented.). We prove the existence and asymptotic behavior of at least one non-trivial solution. For this, we exploit a suitable tricky step analysis of the critical mountain pass level, combined with a Brézis and Lieb-type lemma for fractional Sobolev spaces with variable order and variable exponent.
- Published
- 2020
71. Global stability of a multistrain SIS model with superinfection and patch structure
- Author
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Gergely Röst, Attila Dénes, and Yoshiaki Muroya
- Subjects
Sequence ,General Mathematics ,010102 general mathematics ,Patch model ,General Engineering ,Structure (category theory) ,medicine.disease_cause ,01 natural sciences ,Stability (probability) ,010101 applied mathematics ,Nonlinear system ,Superinfection ,medicine ,Applied mathematics ,0101 mathematics ,Mathematics - Abstract
We study the global stability of a multistrain SIS model with superinfection and patch structure. We establish an iterative procedure to obtain a sequence of threshold parameters. By a repeated application of a result by Takeuchi et al. [Nonlinear Anal Real World Appl. 2006 7:235-247], we show that these parameters completely determine the global dynamics of the system: for any number of patches and strains with different infectivities, any subset of the strains can stably coexist depending on the particular choice of the parameters. Finally, we return to the special case of one patch examined in [Math Biosci Eng. 2017 14:421-35] and give a correction to the proof of Theorem 2.2 of that paper.
- Published
- 2020
72. Nontrivial solutions for impulsive fractional differential systems through variational methods
- Author
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Shapour Heidarkhani and Amjad Salari
- Subjects
Class (set theory) ,General Mathematics ,Weak solution ,010102 general mathematics ,General Engineering ,Term (logic) ,01 natural sciences ,Critical point (mathematics) ,010101 applied mathematics ,Nonlinear system ,Mountain pass theorem ,Applied mathematics ,0101 mathematics ,Algebraic number ,Fractional differential ,Mathematics - Abstract
This paper deals with multiplicity results of solutions for a class of impulsive fractional differential systems. The approach is based on variational methods and critical point theory. Indeed, we establish existence results for our system under some algebraic conditions on the nonlinear part with the classical Ambrosetti–Rabinowitz (AR) condition on the nonlinear and the impulsive terms. Moreover, by combining two algebraic conditions on the nonlinear term which guarantee the existence of two weak solutions, applying the mountain pass theorem we establish the existence of third weak solution for our system.
- Published
- 2020
73. Hierarchic control of a linear heat equation with missing data
- Author
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Romario Gildas Foko Tiomela, Gaston M. N’Guérékata, Gisèle Mophou, Laboratoire de Mathématiques Informatique et Applications (LAMIA), Université des Antilles (UA), Department of Mathematics, Morgan State University, Baltimore, and MOPHOU LOUDJOM, GISELE
- Subjects
Rest (physics) ,General Mathematics ,010102 general mathematics ,Control (management) ,General Engineering ,[MATH] Mathematics [math] ,State (functional analysis) ,Missing data ,Optimal control ,01 natural sciences ,010101 applied mathematics ,Stackelberg strategy ,Stackelberg competition ,[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP] ,Applied mathematics ,Heat equation ,[MATH.MATH-AP] Mathematics [math]/Analysis of PDEs [math.AP] ,[MATH]Mathematics [math] ,0101 mathematics ,ComputingMilieux_MISCELLANEOUS ,Mathematics - Abstract
The paper is devoted to the Stackelberg control of a linear parabolic equation with missing initial conditions. The strategy involves two controls called follower and leader. The objective of the follower is to bring the state to a desired state while the leader has to bring the system to rest at the final time. The results are obtained by means of Fenchel-Legendre transform and appropriate Carleman inequalities.
- Published
- 2020
74. A proper generalized decomposition approach for optical flow estimation
- Author
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B. Denis de Senneville, Abdallah El Hamidi, Nicolas Papadakis, Marwan Saleh, Laboratoire des Sciences de l'Ingénieur pour l'Environnement - UMR 7356 (LaSIE), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Bordeaux (IMB), and Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Optimization ,Weak convergence ,General Mathematics ,Computation ,media_common.quotation_subject ,010102 general mathematics ,General Engineering ,Optical flow ,Fidelity ,Proper Generalized Decomposition (PGD) ,01 natural sciences ,Regularization (mathematics) ,010101 applied mathematics ,Sobolev space ,Quadratic equation ,Optical Flow ,[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing ,Applied mathematics ,[MATH]Mathematics [math] ,0101 mathematics ,Image resolution ,media_common ,Mathematics - Abstract
International audience; This paper introduces the use of the Proper Generalized Decomposition (PGD) method for the optical flow (OF) problem in a classical framework of Sobolev spaces, i.e. optical flow methods including a robust energy for the data fidelity term together with a quadratic penalizer for the regularisation term. A mathematical study of PGD methods is first presented for general regularization problems in the framework of (Hilbert) Sobolev spaces, and their convergence is then illustrated on OF computation. The convergence study is divided in two parts: (i) the weak convergence based on the Brézis-Lieb decomposition, (ii) the strong convergence based on a growth result on the sequence of descent directions. A practical PGD-based OF implementation is then proposed and evaluated on freely available OF data sets. The proposed PGD-based OF approach outperforms the corresponding non-PGD implementation in terms of both accuracy and computation time for images containing a weak level of information, namely low image resolution and/or low Signal-To-Noise Ratio (SNR).
- Published
- 2020
75. Extending the choice of starting points for Newton's method
- Author
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Argyros, Ioannis Konstantinos, Ezquerro, José Antonio, Hernández-Verón, Miguel Ángel, Kim, Young Ik, Magreñán, Ángel Alberto, and 0000-0002-6991-5706
- Subjects
General Mathematics ,010102 general mathematics ,General Engineering ,Lipschitz continuity ,01 natural sciences ,010101 applied mathematics ,symbols.namesake ,symbols ,Order (group theory) ,Applied mathematics ,Center (algebra and category theory) ,0101 mathematics ,Newton's method ,Second derivative ,Mathematics - Abstract
In this paper, we propose a center Lipschitz condition for the second derivative together with the use of restricted domains in order to improve the starting points for Newton's method when compared with previous results. Moreover, we present some numerical examples validating the theoretical results.
- Published
- 2019
76. ‘Stochastic logistic equation with infinite delay’
- Author
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Meng Liu and Ke Wang
- Subjects
Work (thermodynamics) ,Mathematical optimization ,education.field_of_study ,Extinction ,General Mathematics ,Population ,General Engineering ,Critical value ,Quantitative Biology::Populations and Evolution ,Applied mathematics ,Limit (mathematics) ,Logistic function ,Persistence (discontinuity) ,education ,Mathematics ,Competitive system - Abstract
This paper perturbs the famous logistic equation with infinite delay into the corresponding stochastic system This study shows that the above stochastic system has a global positive solution with probability 1 and gives the asymptotic pathwise estimation of this solution. In addition, the superior limit of the average in time of the sample path of the solution is estimated. This work also establishes the sufficient conditions for extinction, nonpersistence in the mean, and weak persistence of the solution. The critical value between weak persistence and extinction is obtained. Then these results are extended to n-dimensional stochastic Lotka–Volterra competitive system with infinite delay. Finally, this paper provides some numerical figures to illustrate the results. The results reveal that, firstly, different types of environmental noises have different effects on the persistence and extinction of the population system; secondly, the delay has no effect on the persistence and extinction of the stochastic system.Copyright © 2012 John Wiley & Sons, Ltd.
- Published
- 2012
77. On the impulsive implicit Ψ‐Hilfer fractional differential equations with delay
- Author
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Jyoti P. Kharade and Kishor D. Kucche
- Subjects
Mathematics::Functional Analysis ,Mathematics - Analysis of PDEs ,Mathematics::Probability ,Mathematics::Complex Variables ,General Mathematics ,Mathematics::Classical Analysis and ODEs ,General Engineering ,Applied mathematics ,Mathematics - Dynamical Systems ,Fractional differential ,Stability (probability) ,Mathematics - Abstract
In this paper, we investigate the existence and uniqueness of solutions and derive the Ulam--Hyers--Mittag--Leffler stability results for impulsive implicit $\Psi$--Hilfer fractional differential equations with time delay. It is demonstrated that the Ulam--Hyers and generalized Ulam--Hyers stability are the specific cases of Ulam--Hyers--Mittag--Leffler stability. Extended version of Gronwall inequality, abstract Gronwall lemma and Picard operator theory are the primary devices in our investigation. We give an example to illustrate the obtained results., Comment: 15
- Published
- 2019
78. Domain of existence for the solution of some IVP's and BVP's by using an efficient ninth‐order iterative method
- Author
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José L. Hueso, Eulalia Martínez, Fabricio Cevallos, and Cory L. Howk
- Subjects
Ninth ,Iterative methods ,Iterative method ,General Mathematics ,010102 general mathematics ,General Engineering ,Nonlinear equations ,01 natural sciences ,Domain (mathematical analysis) ,Computational efficiency ,010101 applied mathematics ,Semilocal convergence ,Rate of convergence ,Order of convergence ,Applied mathematics ,Order (group theory) ,Christian ministry ,0101 mathematics ,MATEMATICA APLICADA ,Mathematics - Abstract
[EN] In this paper, we consider the problem of solving initial value problems and boundary value problems through the point of view of its continuous form. It is well known that in most cases these types of problems are solved numerically by performing a discretization and applying the finite difference technique to approximate the derivatives, transforming the equation into a finite-dimensional nonlinear system of equations. However, we would like to focus on the continuous problem, and therefore, we try to set the domain of existence and uniqueness for its analytic solution. For this purpose, we study the semilocal convergence of a Newton-type method with frozen first derivative in Banach spaces. We impose only the assumption that the Frechet derivative satisfies the Lipschitz continuity condition and that it is bounded in the whole domain in order to obtain appropriate recurrence relations so that we may determine the domains of convergence and uniqueness for the solution. Our final aim is to apply these theoretical results to solve applied problems that come from integral equations, ordinary differential equations, and boundary value problems., Spanish Ministry of Science and Innovation. Grant Number: MTM2014- 52016-C2-2-P Generalitat Valenciana Prometeo. Grant Number: 2016/089
- Published
- 2019
79. The use of partition polynomial series in Laplace inversion of composite functions with applications in fractional calculus
- Author
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Hamed Taghavian
- Subjects
Laplace inversion ,Laplace transform ,General Mathematics ,Composite number ,General Engineering ,Fractional calculus ,symbols.namesake ,Mittag-Leffler function ,symbols ,Partition (number theory) ,Applied mathematics ,Polynomial series ,Laplace transform inversion ,Mathematics - Abstract
This paper presents an analytical method towards Laplace transform inversion of composite functions with the aid of Bell polynomial series. The presented results are used to derive the exact soluti ...
- Published
- 2019
80. On the existence and stability for noninstantaneous impulsive fractional integrodifferential equation
- Author
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Daniela Oliveira, Edmundo Capelas de Oliveira, and José Vanterler da Costa Sousa
- Subjects
Mathematics::Functional Analysis ,26A33, 34A08, 34A12, 34K20, 34G20 ,General Mathematics ,010102 general mathematics ,General Engineering ,01 natural sciences ,Stability (probability) ,010101 applied mathematics ,Mathematics - Classical Analysis and ODEs ,Classical Analysis and ODEs (math.CA) ,FOS: Mathematics ,Applied mathematics ,0101 mathematics ,Mathematics - Abstract
In this paper, by means of Banach fixed point theorem, we investigate the existence and Ulam--Hyers--Rassias stability of the non-instantaneous impulsive integrodifferential equation by means of $\psi$-Hilfer fractional derivative. In this sense, some examples are presented, in order to consolidate the results obtained., Comment: 15 pages
- Published
- 2018
81. Shape memory and phase transitions for auxetic materials.
- Author
-
Ciarletta, Michele, Fabrizio, Mauro, and Tibullo, Vincenzo
- Subjects
SHAPE memory alloys ,PHASE transitions ,AUXETIC materials ,POISSON'S ratio ,APPLIED mathematics - Abstract
We present a mathematical model describing the auxetic-austenitic phase transition phenomenon by a second order shape memory phase transition. The typical properties of auxetic materials, as the negative Poisson ratio ν, are described by a function of the phase ϕ, called order parameter, which relates the phase transition with a change of the internal order structure of the material. In our model, the auxetic phase is represented by an order parameter ϕ = 1, which provides a negative Poisson's ratio, while the austenitic phase will be denoted by ϕ = 0. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
82. Well-posedness and regularity of Euler-Bernoulli equation with variable coefficient and Dirichlet boundary control and collocated observation.
- Author
-
Wen, Ruili, Chai, Shugen, and Guo, Bao‐Zhu
- Subjects
EULER-Bernoulli beam theory ,DIRICHLET problem ,RIEMANNIAN manifolds ,CONTROLLABILITY in systems engineering ,APPLIED mathematics - Abstract
Two types of open-loop systems of an Euler-Bernoulli equation with variable coefficient and Dirichlet boundary control and collocated observation are considered. The uncontrolled boundary is either hinged or clamped. It is shown, with the help of multiplier method on Riemannian manifold, that in both cases, systems are well-posed in the sense of D. Salamon and regular in the sense of G. Weiss. In addition, the feedthrough operators are found to be zero. The result implies that the exact controllability of open-loop is equivalent to the exponential stability of closed-loop under a proportional output feedback for these systems. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
83. Derivation of Korteweg-de Vries flow equations from the short-wave model equation.
- Author
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Koparan, Murat
- Subjects
KORTEWEG-de Vries equation ,HAMILTONIAN systems ,NONLINEAR differential equations ,MATHEMATICAL models ,APPLIED mathematics - Abstract
We perform a multiple-time scales analysis and compatibility condition to the short-wave model equation. We derive Korteweg-de Vries flow equation in the bi-Hamiltonian form as an amplitude equation. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
84. Fractional h‐differences with exponential kernels and their monotonicity properties
- Author
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Shahd Owies, Thabet Abdeljawad, and Iyad Suwan
- Subjects
010101 applied mathematics ,General Mathematics ,010102 general mathematics ,General Engineering ,Applied mathematics ,Monotonic function ,0101 mathematics ,01 natural sciences ,Exponential function ,Mathematics - Abstract
SPECIAL ISSUE PAPER Fractional ℎ ‐differences with exponential kernels and their monotonicity properties Iyad Suwan Shahd Owies Thabet Abdeljawad Mathematical Methods in the Applied Sciences, Early View First published: 25 January 2020
- Published
- 2020
85. Effective numerical evaluation of the double Hilbert transform
- Author
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Min Ku, Xiaoyun Sun, Ieng Tak Leong, and Pei Dang
- Subjects
Pointwise ,General Mathematics ,010102 general mathematics ,General Engineering ,01 natural sciences ,010101 applied mathematics ,Periodic function ,Quadratic formula ,symbols.namesake ,symbols ,Applied mathematics ,Nyström method ,Hilbert transform ,0101 mathematics ,Remainder ,Energy (signal processing) ,Mathematics ,Trigonometric interpolation - Abstract
In this paper, we propose two methods to compute the double Hilbert transform of periodic functions. First, we establish the quadratic formula of trigonometric interpolation type for double Hilbert transform and obtain an estimation of the remainder. We call this method 2D mechanical quadrature method (2D-MQM). Numerical experiments show that 2D-MQM outperforms the library function “hilbert” in Matlab when the values of the functions being handled are very large or approach to infinity. Second, we propose a complex analytic method to calculate the double Hilbert transform, which is based on the 2D adaptive Fourier decomposition, and the method is called as 2D-HAFD. In contrast to the pointwise approximation, 2D-HAFD provides explicit rational functional approximations and is valid for all signals of finite energy.
- Published
- 2020
86. Iterative methods for solving fourth‐ and sixth‐order time‐fractional Cahn‐Hillard equation
- Author
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Udoh Akpan, Lanre Akinyemi, and Olaniyi S. Iyiola
- Subjects
Iterative method ,Sixth order ,General Mathematics ,media_common.quotation_subject ,010102 general mathematics ,General Engineering ,01 natural sciences ,Fractional calculus ,010101 applied mathematics ,Nonlinear fractional differential equations ,Exact solutions in general relativity ,Applied mathematics ,Simplicity ,0101 mathematics ,Convergent series ,Analysis method ,Mathematics ,media_common - Abstract
This paper presents analytical-approximate solutions of the time-fractional Cahn-Hilliard (TFCH) equations of fourth and sixth-order using the new iterative method (NIM) and q-homotopy analysis method (q-HAM). We obtained convergent series solutions using these iterative methods. The simplicity and accuracy of these methods in solving strongly nonlinear fractional differential equations is displayed through the examples provided. In the case where exact solution exists, error estimates are also investigated.
- Published
- 2020
87. Cobweb model with conformable fractional derivatives
- Author
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Martin Bohner and Veysel Fuat Hatipoğlu
- Subjects
0209 industrial biotechnology ,General Mathematics ,General Engineering ,010103 numerical & computational mathematics ,02 engineering and technology ,Conformable matrix ,01 natural sciences ,Fractional calculus ,020901 industrial engineering & automation ,Computer Science::Discrete Mathematics ,Applied mathematics ,Cobweb model ,0101 mathematics ,Mathematics - Abstract
In this paper, the cobweb model is reformulated in terms of fractional-order derivatives. In particular, we describe linear cobweb models in continuous time by using conformable fractional-order derivatives. Then, the general solutions as well as stability criteria for the proposed models are given. Moreover, the developed models are illustrated with some examples.
- Published
- 2018
88. Symmetry analysis for a Fisher equation with exponential diffusion
- Author
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Maria Luz Gandarias, María Rosa, and Rita Tracinà
- Subjects
education.field_of_study ,Partial differential equation ,General Mathematics ,Symmetry reductions ,010102 general mathematics ,Population ,General Engineering ,Fisher equation ,Partial differential equations ,01 natural sciences ,Symmetry (physics) ,010305 fluids & plasmas ,Exponential function ,Engineering (all) ,0103 physical sciences ,Heat transfer ,Mathematics (all) ,Applied mathematics ,0101 mathematics ,Diffusion (business) ,education ,Equivalence (measure theory) ,Mathematics - Abstract
In this paper, we consider a generalized Fisher equation with exponential diffusion from the point of view of the theory of symmetry reductions in partial differential equations. The generalized Fisher-type equation arises in the theory of population dynamics. These types of equations have appeared in many fields of study such as in the reaction-diffusion equations, in heat transfer problems, in biology, and in chemical kinetics. By using the symmetry classification, simplified by equivalence transformations, for a special family of Fisher equations, all the reductions are derived fromthe optimal systemof subalgebras and symmetry reductions are used to obtain exact solutions.
- Published
- 2018
89. A practical approach to R 0 in continuous‐time ecological models
- Author
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Àngel Calsina, Carles Barril, and Jordi Ripoll
- Subjects
0301 basic medicine ,education.field_of_study ,Unit of time ,General Mathematics ,Computation ,Population ,General Engineering ,Linear model ,Space (mathematics) ,01 natural sciences ,Population density ,010101 applied mathematics ,03 medical and health sciences ,030104 developmental biology ,Population model ,Econometrics ,Quantitative Biology::Populations and Evolution ,Applied mathematics ,0101 mathematics ,education ,Basic reproduction number ,Mathematics - Abstract
In this paper we study the asymptotic behaviour of the solutions in linear models of population dynamics by means of the basic reproduction number R0. Our aim is to give a practical approach to the computation of the basic reproduction number in continuous-time population models structured by age and/or space. The procedure is different depending on whether the density of newborns per time unit and the density of population belong to the same functional space or not. Three infinite-dimensional examples are illustrated: a transport model for a cell population, a model of spatial diffusion of individuals in a habitat, and a model of migration of individuals between age-structured local populations. For each model, we have highlighted the possible advantages of computing R0 instead of the Malthusian parameter.
- Published
- 2017
90. A self-adaptive intelligence gray prediction model with the optimal fractional order accumulating operator and its application
- Author
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Bo Zeng and Sifeng Liu
- Subjects
0209 industrial biotechnology ,Mathematical optimization ,Estimation theory ,General Mathematics ,General Engineering ,Particle swarm optimization ,Self adaptive ,02 engineering and technology ,Order number ,020901 industrial engineering & automation ,0202 electrical engineering, electronic engineering, information engineering ,Applied mathematics ,020201 artificial intelligence & image processing ,Gray (horse) ,Mathematics - Abstract
The self-adaptive intelligence gray predictive model (SAIGM) has an alterable-flexible model structure, and it can build a dynamic structure to fit different external environments by adjusting the parameter values of SAIGM. However, the order number of the raw SAIGM model is not optimal, which is an integer. For this, a new SAIGM model with the fractional order accumulating operator (SAIGM_FO) was proposed in this paper. Specifically, the final restored expression of SAIGM_FO was deduced in detail, and the parameter estimation method of SAIGM_FO was studied. After that, the Particle Swarm Optimization algorithm was used to optimize the order number of SAIGM_FO, and some steps were provided. Finally, the SAIGM_FO model was applied to simulate China's electricity consumption from 2001 to 2008 and forecast it during 2009 to 2015, and the mean relative simulation and prediction percentage errors of the new model were only 0.860% and 2.661%, in comparison with the ones obtained from the raw SAIGM model, the GM(1, 1) model with the optimal fractional order accumulating operator and the GM(1, 1) model, which were (1.201%, 5.321%), (1.356%, 3.324%), and (2.013%, 23.944%), respectively. The findings showed both the simulation and the prediction performance of the proposed SAIGM_FO model were the best among the 4 models.
- Published
- 2017
91. Permanence and extinction of a nonautonomous impulsive plankton model with help
- Author
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Shutang Liu, Wen Wang, Dadong Tian, and Qiuyue Zhao
- Subjects
Extinction ,General Mathematics ,010102 general mathematics ,0103 physical sciences ,General Engineering ,Quantitative Biology::Populations and Evolution ,Applied mathematics ,0101 mathematics ,Plankton ,01 natural sciences ,010305 fluids & plasmas ,Mathematics - Abstract
In this paper, we consider a nonautonomous impulsive plankton model with mutual help of preys. Sufficient conditions ensuring permanence and global attractivity of the model are established by the relation between solutions of impulsive system and corresponding nonimpulsive system. Also, we propose the conditions for which the species of system are driven to extinction. Numerical simulations are given to verify the main results.
- Published
- 2017
92. Convergence analysis for second-order accurate schemes for the periodic nonlocal Allen-Cahn and Cahn-Hilliard equations
- Author
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Cheng Wang, Zhen Guan, and John Lowengrub
- Subjects
Consistency analysis ,Spacetime ,General Mathematics ,General Engineering ,Regular polygon ,010103 numerical & computational mathematics ,01 natural sciences ,Standard procedure ,010101 applied mathematics ,Nonlinear system ,Energy stability ,Norm (mathematics) ,Applied mathematics ,0101 mathematics ,Approximate solution ,Mathematics - Abstract
In this paper we provide a detailed convergence analysis for fully discrete second order (in both time and space) numerical schemes for nonlocal Allen-Cahn (nAC) and nonlocal Cahn-Hilliard (nCH) equations. The unconditional unique solvability and energy stability ensures $\ell^4$ stability. The convergence analysis for the nAC equation follows the standard procedure of consistency and stability estimate for the numerical error function. For the nCH equation, due to the complicated form of the nonlinear term, a careful expansion of its discrete gradient is undertaken and an $H^{-1}$ inner product estimate of this nonlinear numerical error is derived to establish convergence. In addition, an a-priori $W^{1,\infty}$ bound of the numerical solution at the discrete level is needed in the error estimate. Such a bound can be obtained by performing a higher order consistency analysis by using asymptotic expansions for the numerical solution. Following the technique originally proposed by Strang (e.g., 1964), instead of the standard comparison between the exact and numerical solutions, an error estimate between the numerical solution and the constructed approximate solution yields an $O( s^3 + h^4)$ convergence in $\ell^\infty (0, T; \ell^2)$ norm, which leads to the necessary bound under a standard constraint $s \le C h$. Here, we also prove convergence of the scheme in the maximum norm under the same constraint.
- Published
- 2017
93. Dynamics of a ratio-dependent stage-structured predator-prey model with delay
- Author
-
Yongli Song, Tao Yin, and Hongying Shu
- Subjects
Hopf bifurcation ,Steady state ,General Mathematics ,Dynamics (mechanics) ,General Engineering ,Structure (category theory) ,01 natural sciences ,Stability (probability) ,Instability ,010305 fluids & plasmas ,010101 applied mathematics ,symbols.namesake ,Control theory ,0103 physical sciences ,symbols ,Quantitative Biology::Populations and Evolution ,Applied mathematics ,0101 mathematics ,Reduction (mathematics) ,Center manifold ,Mathematics - Abstract
In this paper, we investigate the dynamics of a time-delay ratio-dependent predator-prey model with stage structure for the predator. This predator-prey system conforms to the realistically biological environment. The existence and stability of the positive equilibrium are thoroughly analyzed, and the sufficient and necessary conditions for the stability and instability of the positive equilibrium are obtained for the case without delay. Then, the influence of delay on the dynamics of the system is investigated using the geometric criterion developed by Beretta and Kuang.[26] We show that the positive steady state can be destabilized through a Hopf bifurcation and there exist stability switches under some conditions. The formulas determining the direction and the stability of Hopf bifurcations are explicitly derived by using the center manifold reduction and normal form theory. Finally, some numerical simulations are performed to illustrate and expand our theoretical results.
- Published
- 2017
94. The impact of constant effort harvesting on the dynamics of a discrete-time contest competition model
- Author
-
Amal Amleh and Ziyad AlSharawi
- Subjects
0106 biological sciences ,General Mathematics ,General Engineering ,Function (mathematics) ,CONTEST ,010603 evolutionary biology ,01 natural sciences ,Stability (probability) ,Intraspecific competition ,010101 applied mathematics ,Discrete time and continuous time ,Applied mathematics ,0101 mathematics ,Invariant (mathematics) ,Constant (mathematics) ,Mathematical economics ,Scramble competition ,Mathematics - Abstract
In this paper, we study a general discrete-time model representing the dynamics of a contest competition species with constant effort exploitation. In particular, we consider the difference equation xn+1=xnf(xn−k)−hxn where h>0, k∈{0,1}, and the density dependent function f satisfies certain conditions that are typical of a contest competition. The harvesting parameter h is considered as the main parameter, and its effect on the general dynamics of the model is investigated. In the absence of delay in the recruitment (k=0), we show the effect of h on the stability, the maximum sustainable yield, the persistence of solutions, and how the intraspecific competition change from contest to scramble competition. When the delay in recruitment is 1 (k=1), we show that a Neimark-Sacker bifurcation occurs, and the obtained invariant curve is supercritical. Furthermore, we give a characterization of the persistent set.
- Published
- 2017
95. Stepanov-like doubly weighted pseudo almost automorphic processes and its application to Sobolev-type stochastic differential equations driven byG-Brownian motion
- Author
-
Qigui Yang and Ping Zhu
- Subjects
Zero set ,Stochastic process ,General Mathematics ,010102 general mathematics ,Mathematical analysis ,General Engineering ,01 natural sciences ,010101 applied mathematics ,Sobolev space ,Nonlinear system ,Stochastic differential equation ,Applied mathematics ,Ergodic theory ,Uniqueness ,0101 mathematics ,Brownian motion ,Mathematics - Abstract
This paper investigates the properties of the p-mean Stepanov-like doubly weighted pseudo almost automorphic (SpDWPAA) processes and its application to Sobolev-type stochastic differential equations driven by G-Brownian motion. We firstly prove the equivalent relation between the SpDWPAA and Stepanov-like asymptotically almost automorphic stochastic processes based on ergodic zero set. We further establish the completeness of the space and the composition theorem for SpDWPAA processes. These results obtained improve and extend previous related conclusions. As an application, we show the existence and uniqueness of the Sp DWPAA solution for a class of nonlinear Sobolev-type stochastic differential equations driven by G-Brownian motion and present a decomposition of this unique solution. Moreover, an example is given to illustrate the effectiveness of our results.
- Published
- 2017
96. Global dynamics of a Vector-Borne disease model with two delays and nonlinear transmission rate
- Author
-
Dan Tian and Haitao Song
- Subjects
General Mathematics ,Transmission rate ,Dynamics (mechanics) ,General Engineering ,01 natural sciences ,010305 fluids & plasmas ,Incubation period ,010101 applied mathematics ,Nonlinear system ,Lyapunov functional ,Control theory ,Stability theory ,0103 physical sciences ,Applied mathematics ,0101 mathematics ,Basic reproduction number ,Nonlinear incidence rate ,Mathematics - Abstract
In this paper, we investigate a Vector-Borne disease model with nonlinear incidence rate and 2 delays: One is the incubation period in the vectors and the other is the incubation period in the host. Under the biologically motivated assumptions, we show that the global dynamics are completely determined by the basic reproduction number R0. The disease-free equilibrium is globally asymptotically stable if R0≤1; when R0>1, the system is uniformly persistent, and there exists a unique endemic equilibrium that is globally asymptotically. Numerical simulations are conducted to illustrate the theoretical results.
- Published
- 2017
97. Multigroup deterministic and stochasticSEIRIepidemic models with nonlinear incidence rates and distributed delays: A stability analysis
- Author
-
Paul Georgescu, Hong Zhang, and Juan Xia
- Subjects
Lyapunov stability ,Mathematical optimization ,Invariance principle ,General Mathematics ,010102 general mathematics ,General Engineering ,Delay differential equation ,White noise ,Type (model theory) ,Nonlinear incidence ,01 natural sciences ,Stability (probability) ,010101 applied mathematics ,Lyapunov functional ,Applied mathematics ,0101 mathematics ,Mathematics - Abstract
In this paper, we investigate the dynamics of a multigroup disease propagation model with distributed delays and nonlinear incidence rates, which accounts for the relapse of recovered individuals. The main concern is the stability of the equilibria, sufficient conditions for global stability being obtained by applying Lyapunov-LaSalle invariance principle and using Lyapunov functionals, which are constructed using their single-group counterparts. The situation in which the deterministic model is subject to perturbations of white noise type is also investigated from a stability viewpoint.
- Published
- 2017
98. A new computational method for solving two-dimensional Stratonovich Volterra integral equation
- Author
-
Elham Hadadian and Farshid Mirzaee
- Subjects
General Mathematics ,010102 general mathematics ,Mathematical analysis ,Linear system ,General Engineering ,01 natural sciences ,Volterra integral equation ,010104 statistics & probability ,Algebraic equation ,symbols.namesake ,Operational matrix ,Error analysis ,symbols ,Applied mathematics ,0101 mathematics ,Mathematics - Abstract
This paper presents a method for computing numerical solutions of two-dimensional Stratonovich Volterra integral equations using one-dimensional modification of hat functions and two-dimensional modification of hat functions. The problem is transformed to a linear system of algebraic equations using the operational matrix associated with one-dimensional modification of hat functions and two-dimensional modification of hat functions. The error analysis of the method is given. The method is computationally attractive, and applications are demonstrated by a numerical example. Copyright © 2017 John Wiley & Sons, Ltd.
- Published
- 2017
99. A delayed prey-predator model with Crowley-Martin-type functional response including prey refuge
- Author
-
Balram Dubey, Atasi Patra Maiti, and Jai Tushar
- Subjects
Hopf bifurcation ,General Mathematics ,010102 general mathematics ,General Engineering ,Functional response ,Type (model theory) ,01 natural sciences ,Stability (probability) ,010305 fluids & plasmas ,Predation ,symbols.namesake ,Control theory ,0103 physical sciences ,symbols ,Quantitative Biology::Populations and Evolution ,Applied mathematics ,Prey predator ,0101 mathematics ,Predator ,Bifurcation ,Mathematics - Abstract
In this paper, we have studied a prey–predator model living in a habitat that divided into two regions: an unreserved region and a reserved (refuge) region. The migration between these two regions is allowed. The interaction between unreserved prey and predator is Crowley–Martin-type functional response. The local and global stability of the system is discussed. Further, the system is extended to incorporate the effect of time delay. Then the dynamical behavior of the system is analyzed, taking delay as a bifurcation parameter. The direction of Hopf bifurcation and the stability of the bifurcated periodic solution are determined with the help of normal form theory and centre manifold theorem. We have also discussed the influence of prey refuge on densities of prey and predator species. The analytical results are supplemented with numerical simulations. Copyright © 2017 John Wiley & Sons, Ltd.
- Published
- 2017
100. Stability and bifurcation in epidemic models describing the transmission of toxoplasmosis in human and cat populations
- Author
-
Jocirei D. Ferreira, Luz Myriam Echeverry, and Carlos Arturo Peña Rincón
- Subjects
0301 basic medicine ,Equilibrium point ,General Mathematics ,030231 tropical medicine ,General Engineering ,Ode ,Octant (solid geometry) ,Stability (probability) ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Stability theory ,Ordinary differential equation ,Reaction–diffusion system ,Applied mathematics ,Mathematical economics ,Bifurcation ,Mathematics - Abstract
A five-dimensional ordinary differential equation model describing the transmission of Toxoplamosis gondii disease between human and cat populations is studied in this paper. Self-diffusion modeling the spatial dynamics of the T. gondii disease is incorporated in the ordinary differential equation model. The normalized version of both models where the unknown functions are the proportions of the susceptible, infected, and controlled individuals in the total population are analyzed. The main results presented herein are that the ODE model undergoes a trans-critical bifurcation, the system has no periodic orbits inside the positive octant, and the endemic equilibrium is globally asymptotically stable when we restrict the model to inside of the first octant. Furthermore, a local linear stability analysis for the spatially homogeneous equilibrium points of the reaction diffusion model is carried out, and the global stability of both the disease-free and endemic equilibria are established for the reaction–diffusion system when restricted to inside of the first octant. Finally, numerical simulations are provided to support our theoretical results and to predict some scenarios about the spread of the disease. Copyright © 2017 John Wiley & Sons, Ltd.
- Published
- 2017
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