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  1. Book ; Online: Symmetry in Complex Systems

    Machado, J. A. Tenreiro / Lopes, António

    2020  

    Keywords History of engineering & technology ; multi-agent system (MAS) ; reinforcement learning (RL) ; mobile robots ; function approximation ; Opportunistic complex social network ; cooperative ; neighbor node ; probability model ; social relationship ; adapted PageRank algorithm ; PageRank vector ; networks centrality ; multiplex networks ; biplex networks ; divided difference ; radius of convergence ; Kung-Traub method ; local convergence ; Lipschitz constant ; Banach space ; fractional calculus ; Caputo derivative ; generalized Fourier law ; Laplace transform ; Fourier transform ; Mittag-Leffler function ; non-Fourier heat conduction ; Mei symmetry ; conserved quantity ; adiabatic invariant ; quasi-fractional dynamical system ; non-standard Lagrangians ; complex systems ; symmetry-breaking ; bifurcation theory ; complex networks ; nonlinear dynamical systems
    Size 1 electronic resource (118 pages)
    Publisher MDPI - Multidisciplinary Digital Publishing Institute
    Publishing place Basel, Switzerland
    Document type Book ; Online
    Note English ; Open Access
    HBZ-ID HT021044706
    ISBN 9783039368952 ; 3039368958
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

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  2. Book ; Online: Entropy in Dynamic Systems

    Tenreiro Machado, J. A. / Awrejcewicz, Jan

    2019  

    Abstract: In order to measure and quantify the complex behavior of real-world systems, either novel mathematical approaches or modifications of classical ones are required to precisely predict, monitor, and control complicated chaotic and stochastic processes. ... ...

    Abstract In order to measure and quantify the complex behavior of real-world systems, either novel mathematical approaches or modifications of classical ones are required to precisely predict, monitor, and control complicated chaotic and stochastic processes. Though the term of entropy comes from Greek and emphasizes its analogy to energy, today, it has wandered to different branches of pure and applied sciences and is understood in a rather rough way, with emphasis placed on the transition from regular to chaotic states, stochastic and deterministic disorder, and uniform and non-uniform distribution or decay of diversity. This collection of papers addresses the notion of entropy in a very broad sense. The presented manuscripts follow from different branches of mathematical/physical sciences, natural/social sciences, and engineering-oriented sciences with emphasis placed on the complexity of dynamical systems. Topics like timing chaos and spatiotemporal chaos, bifurcation, synchronization and anti-synchronization, stability, lumped mass and continuous mechanical systems modeling, novel nonlinear phenomena, and resonances are discussed
    Keywords Technology (General) ; Engineering (General). Civil engineering (General)
    Size 1 electronic resource (172 pages)
    Publisher MDPI - Multidisciplinary Digital Publishing Institute
    Document type Book ; Online
    Note eng ; Open Access
    HBZ-ID HT020324037
    ISBN 9783039216161 ; 9783039216178 ; 3039216163 ; 3039216171
    DOI 10.3390/books978-3-03921-617-8
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

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  3. Article ; Online: Guaranteed cost-based feedback control design for fractional-order neutral systems with input-delayed and nonlinear perturbations.

    Aghayan, Zahra Sadat / Alfi, Alireza / Tenreiro Machado, J A

    ISA transactions

    2022  Volume 131, Page(s) 95–107

    Abstract: Time delay in actuators is mainly caused by electrical and mechanical components. The effect is visible in the system response particularly when changing in the input command. Therefore, input delay is a problem in the control system design that must be ... ...

    Abstract Time delay in actuators is mainly caused by electrical and mechanical components. The effect is visible in the system response particularly when changing in the input command. Therefore, input delay is a problem in the control system design that must be taken into account. Besides, ignoring uncertainty in the dynamic models may compromise the controller design. Thus, how to mitigate the effect of this issue on the system stability and performance is a challenging topic. This article deals with the stabilization of fractional neutral systems considering input-delayed and nonlinear perturbations using the guaranteed cost-based feedback control technique. The main focus is to design the state- and output-feedback controllers to achieve a good performance. The stability criteria are formulated in the Lyapunov sense, which are described in terms of matrix inequalities. The proposed idea is validated using simulations.
    Language English
    Publishing date 2022-05-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2012746-7
    ISSN 1879-2022 ; 0019-0578
    ISSN (online) 1879-2022
    ISSN 0019-0578
    DOI 10.1016/j.isatra.2022.05.002
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Nonlinear dynamics of COVID-19 pandemic: modeling, control, and future perspectives.

    Tenreiro Machado, J A / Ma, Jun

    Nonlinear dynamics

    2020  Volume 101, Issue 3, Page(s) 1525–1526

    Keywords covid19
    Language English
    Publishing date 2020-09-03
    Publishing country Netherlands
    Document type Editorial
    ZDB-ID 2012600-1
    ISSN 1573-269X ; 0924-090X
    ISSN (online) 1573-269X
    ISSN 0924-090X
    DOI 10.1007/s11071-020-05919-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Modified SIQR model for the COVID-19 outbreak in several countries.

    Pinto, Carla M A / Tenreiro Machado, J A / Burgos-Simón, Clara

    Mathematical methods in the applied sciences

    2022  

    Abstract: In this paper, we propose a modified Susceptible-Infected-Quarantine-Recovered (mSIQR) model, for the COVID-19 pandemic. We start by proving the well-posedness of the model and then compute its reproduction number and the corresponding sensitivity ... ...

    Abstract In this paper, we propose a modified Susceptible-Infected-Quarantine-Recovered (mSIQR) model, for the COVID-19 pandemic. We start by proving the well-posedness of the model and then compute its reproduction number and the corresponding sensitivity indices. We discuss the values of these indices for epidemiological relevant parameters, namely, the contact rate, the proportion of unknown infectious, and the recovering rate. The mSIQR model is simulated, and the outputs are fit to COVID-19 pandemic data from several countries, including France, US, UK, and Portugal. We discuss the epidemiological relevance of the results and provide insights on future patterns, subjected to health policies.
    Language English
    Publishing date 2022-01-17
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478610-2
    ISSN 1099-1476 ; 0170-4214
    ISSN (online) 1099-1476
    ISSN 0170-4214
    DOI 10.1002/mma.8082
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Entropy analysis of human death uncertainty.

    Tenreiro Machado, J A / Lopes, António M

    Nonlinear dynamics

    2021  Volume 104, Issue 4, Page(s) 3897–3911

    Abstract: Uncertainty about the time of death is part of one's life, and plays an important role in demographic and actuarial sciences. Entropy is a measure useful for characterizing complex systems. This paper analyses death uncertainty through the concept of ... ...

    Abstract Uncertainty about the time of death is part of one's life, and plays an important role in demographic and actuarial sciences. Entropy is a measure useful for characterizing complex systems. This paper analyses death uncertainty through the concept of entropy. For that purpose, the Shannon and the cumulative residual entropies are adopted. The first may be interpreted as an average information. The second was proposed more recently and is related to reliability measures such as the mean residual lifetime. Data collected from the Human Mortality Database and describing the evolution of 40 countries during several decades are studied using entropy measures. The emerging country and inter-country entropy patterns are used to characterize the dynamics of mortality. The locus of the two entropies gives a deeper insight into the dynamical evolution of the human mortality data series.
    Language English
    Publishing date 2021-05-21
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 2012600-1
    ISSN 1573-269X ; 0924-090X
    ISSN (online) 1573-269X
    ISSN 0924-090X
    DOI 10.1007/s11071-021-06503-2
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: New discrete-time fractional derivatives based on the bilinear transformation: Definitions and properties.

    Ortigueira, Manuel D / Tenreiro Machado, J A

    Journal of advanced research

    2020  Volume 25, Page(s) 1–10

    Abstract: In this paper we introduce new discrete-time derivative concepts based on the bilinear (Tustin) transformation. From the new formulation, we obtain derivatives that exhibit a high degree of similarity with the continuous-time Grünwald-Letnikov ... ...

    Abstract In this paper we introduce new discrete-time derivative concepts based on the bilinear (Tustin) transformation. From the new formulation, we obtain derivatives that exhibit a high degree of similarity with the continuous-time Grünwald-Letnikov derivatives. Their properties are described highlighting one important feature, namely that such derivatives have always long memory.
    Language English
    Publishing date 2020-02-25
    Publishing country Egypt
    Document type Journal Article ; Review
    ZDB-ID 2541849-X
    ISSN 2090-1224 ; 2090-1232
    ISSN (online) 2090-1224
    ISSN 2090-1232
    DOI 10.1016/j.jare.2020.02.011
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Multidimensional scaling locus of memristor and fractional order elements.

    Tenreiro Machado, J A / Lopes, António M

    Journal of advanced research

    2020  Volume 25, Page(s) 147–157

    Abstract: This paper combines the synergies of three mathematical and computational generalizations. The concepts of fractional calculus, memristor and information visualization extend the classical ideas of integro-differential calculus, electrical elements and ... ...

    Abstract This paper combines the synergies of three mathematical and computational generalizations. The concepts of fractional calculus, memristor and information visualization extend the classical ideas of integro-differential calculus, electrical elements and data representation, respectively. The study embeds these notions in a common framework, with the objective of organizing and describing the "continuum" of fractional order elements (FOE). Each FOE is characterized by its behavior, either in the time or in the frequency domains, and the differences between the FOE are captured by a variety of distinct indices, such as the Arccosine, Canberra, Jaccard and Sørensen distances. The dissimilarity information is processed by the multidimensional scaling (MDS) computational algorithm to unravel possible clusters and to allow a direct pattern visualization. The MDS yields 3-dimensional loci organized according to the FOE characteristics both for linear and nonlinear elements. The new representation generalizes the standard Cartesian 2-dimensional periodic table of elements.
    Language English
    Publishing date 2020-01-20
    Publishing country Egypt
    Document type Journal Article ; Review
    ZDB-ID 2541849-X
    ISSN 2090-1224 ; 2090-1232
    ISSN (online) 2090-1224
    ISSN 2090-1232
    DOI 10.1016/j.jare.2020.01.004
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: An Entropy Formulation Based on the Generalized Liouville Fractional Derivative.

    Ferreira, Rui A C / Tenreiro Machado, J

    Entropy (Basel, Switzerland)

    2019  Volume 21, Issue 7

    Abstract: This paper presents a new formula for the entropy of a distribution, that is conceived having in mind the Liouville fractional derivative. For illustrating the new concept, the proposed definition is applied to the Dow Jones Industrial Average. Moreover, ...

    Abstract This paper presents a new formula for the entropy of a distribution, that is conceived having in mind the Liouville fractional derivative. For illustrating the new concept, the proposed definition is applied to the Dow Jones Industrial Average. Moreover, the Jensen-Shannon divergence is also generalized and its variation with the fractional order is tested for the time series.
    Language English
    Publishing date 2019-06-28
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2014734-X
    ISSN 1099-4300 ; 1099-4300
    ISSN (online) 1099-4300
    ISSN 1099-4300
    DOI 10.3390/e21070638
    Database MEDical Literature Analysis and Retrieval System OnLINE

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