87 research outputs found

    Projective Synchronization of N

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    Based on linear feedback control technique, a projective synchronization scheme of N-dimensional chaotic fractional-order systems is proposed, which consists of master and slave fractional-order financial systems coupled by linear state error variables. It is shown that the slave system can be projectively synchronized with the master system constructed by state transformation. Based on the stability theory of linear fractional order systems, a suitable controller for achieving synchronization is designed. The given scheme is applied to achieve projective synchronization of chaotic fractional-order financial systems. Numerical simulations are given to verify the effectiveness of the proposed projective synchronization scheme

    Neimark-Sacker Bifurcation in a Discrete-Time Financial System

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    A discrete-time financial system is proposed by using forward Euler scheme. Based on explicit Neimark-Sacker bifurcation (also called Hopf bifurcation for map) criterion, normal form method and center manifold theory, the system's existence, stability and direction of Neimark-Sacker bifurcation are studied. Numerical simulations are employed to validate the main results of this work. Some comparison of bifurcation between the discrete-time financial system and its continuous-time system is given

    Comparison of the Mitochondrial Genome Sequences of Six Annulohypoxylon stygium Isolates Suggests Short Fragment Insertions as a Potential Factor Leading to Larger Genomic Size

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    Mitochondrial DNA (mtDNA) is a core non-nuclear genetic material found in all eukaryotic organisms, the size of which varies extensively in the eumycota, even within species. In this study, mitochondrial genomes of six isolates of Annulohypoxylon stygium (LĂ©v.) were assembled from raw reads from PacBio and Illumina sequencing. The diversity of genomic structures, conserved genes, intergenic regions and introns were analyzed and compared. Genome sizes ranged from 132 to 147 kb and contained the same sets of conserved protein-coding, tRNA and rRNA genes and shared the same gene arrangements and orientation. In addition, most intergenic regions were homogeneous and had similar sizes except for the region between cytochrome b (cob) and cytochrome c oxidase I (cox1) genes which ranged from 2,998 to 8,039 bp among the six isolates. Sixty-five intron insertion sites and 99 different introns were detected in these genomes. Each genome contained 45 or more introns, which varied in distribution and content. Introns from homologous insertion sites also showed high diversity in size, type and content. Comparison of introns at the same loci showed some complex introns, such as twintrons and ORF-less introns. There were 44 short fragment insertions detected within introns, intergenic regions, or as introns, some of them located at conserved domain regions of homing endonuclease genes. Insertions of short fragments such as small inverted repeats might affect or hinder the movement of introns, and these allowed for intron accumulation in the mitochondrial genomes analyzed, and enlarged their size. This study showed that the evolution of fungal mitochondrial introns is complex, and the results suggest short fragment insertions as a potential factor leading to larger mitochondrial genomes in A. stygium

    Ecological risk of microplastic toxicity to earthworms in soil: A bibliometric analysis

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    Accumulation of microplastics (MPs) in soil is a serious environmental concern. Addition of exogenous MPs can alter structure and physicochemical properties of and material transport in soil. MPs are particularly toxic to earthworms, which are soil ecosystem engineers, and exacerbate ecological risks; however, there is a lack of comprehensive and in-depth analyses of how MPs exhibit toxicity to/towards earthworms. In this study, we report a bibliometric analysis of 77 peer-reviewed papers published before December 2021 to systematically analyze how the addition of exogenous MPs contributes to earthworm toxicity and clarify the historical development and research hotspots in this field. We found that first, polyethylene and polystyrene are the most common materials used to study the toxic effects of MPs on earthworms. Second, the toxic mechanisms of MPs on earthworms mainly involve histopathological damage and oxidative stress, as well as serving as carriers of complex pollutants (e.g., heavy metals and organic pollutants) through combined adsorption–desorption. Third, oxidative stress is the typical reaction process of MPs toxicity in earthworms. When the content of MPs in soil exceeds 0.1%, earthworm growth is affected, and oxidative stress is induced, resulting in neural and DNA damage. Based on published studies, the prospects for future research on the ecological risks posed by MPs to earthworms have also been discussed. Overall, our findings help clarify the ecological risk of soil MPs toxicity to earthworms, reveal the mechanism of their toxic effects, and provide a theoretical basis for future studies focusing on establishing a healthy and ecologically sustainable soil environment

    On a master-slave Bertrand game model

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    A master-slave Bertrand game model is proposed for upstream and downstream monopolies owned by different parties, in which the upstream monopolist's output is used as the main factor of production by the downstream monopolist who is a small purchaser of the upstream monopolist's output. The bifurcation of the Bertrand-Nash equilibrium is analyzed with Schwarzian derivative. Numerical simulations are employed to show the model's complex dynamics by means of the largest Lyapunov exponents (LLEs), bifurcation, time series diagrams and phase portraits. With the modified straight-line stabilization method, chaos control is used to improve the aggregate profits of the two oligopolists. Lastly the welfare impacts of price fluctuations and chaos controls are briefly discussed.Bertrand game Bifurcations Welfare cost Chaos control Consumer surplus

    Optimal Financing Decisions of Two Cash-Constrained Supply Chains with Complementary Products

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    In recent years; financing difficulties have been obsessed small and medium enterprises (SMEs); especially emerging SMEs. Inter-members’ joint financing within a supply chain is one of solutions for SMEs. How about members’ joint financing of inter-supply chains? In order to answer the question, we firstly employ the Stackelberg game to propose three kinds of financing decision models of two cash-constrained supply chains with complementary products. Secondly, we analyze qualitatively these models and find the joint financing decision of the two supply chains is the most optimal one. Lastly, we conduct some numerical simulations not only to illustrate above results but also to find that the larger are cross-price sensitivity coefficients; the higher is the motivation for participants to make joint financing decisions; and the more are profits for them to gain

    Synchronization of Chaotic Fractional-Order WINDMI Systems via Linear State Error Feedback Control

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    We propose a fractional-order WINDMI system, as a generalization of an integer-order system developed by Sprott (2003). The considered synchronization scheme consists of identical master and slave fractional-order WINDMI systems coupled by linear state error variables. Based on the stability theory of nonlinear fractional-order systems, linear state error feedback control technique is applied to achieve chaos synchronization, and a linear control law is derived analytically to achieve synchronization of the chaotic fractional-order WINDMI system. Numerical simulations validate the main results of this work

    A Viscosity Approximation Scheme for Finding Common Solutions of Mixed Equilibrium Problems, a Finite Family of Variational Inclusions, and Fixed Point Problems in Hilbert Spaces

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    We introduce an iterative method for finding a common element of set of fixed points of nonexpansive mappings, the set of solutions of a finite family of variational inclusion with set-valued maximal monotone mappings and inverse strongly monotone mappings, and the set of solutions of a mixed equilibrium problem in Hilbert spaces. Under suitable conditions, some strong convergence theorems for approximating this common elements are proved. The results presented in the paper improve and extend the main results of Plubtemg and Sripard and many others
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