scholarly journals Improving Entropy Estimates of Complex Network Topology for the Characterization of Coupling in Dynamical Systems

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 891 ◽  
Author(s):  
Teddy Craciunescu ◽  
Andrea Murari ◽  
Michela Gelfusa

A new measure for the characterization of interconnected dynamical systems coupling is proposed. The method is based on the representation of time series as weighted cross-visibility networks. The weights are introduced as the metric distance between connected nodes. The structure of the networks, depending on the coupling strength, is quantified via the entropy of the weighted adjacency matrix. The method has been tested on several coupled model systems with different individual properties. The results show that the proposed measure is able to distinguish the degree of coupling of the studied dynamical systems. The original use of the geodesic distance on Gaussian manifolds as a metric distance, which is able to take into account the noise inherently superimposed on the experimental data, provides significantly better results in the calculation of the entropy, improving the reliability of the coupling estimates. The application to the interaction between the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole and to the influence of ENSO on influenza pandemic occurrence illustrates the potential of the method for real-life problems.

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zheng Kou ◽  
Saeed Kosari ◽  
Maryam Akhoundi

Fuzzy graph (FG) models embrace the ubiquity of existing in natural and man-made structures, specifically dynamic processes in physical, biological, and social systems. It is exceedingly difficult for an expert to model those problems based on a FG because of the inconsistent and indeterminate information inherent in real-life problems being often uncertain. Vague graph (VG) can deal with the uncertainty associated with the inconsistent and determinate information of any real-world problem, where FGs many fail to reveal satisfactory results. Regularity definitions have been of high significance in the network heterogeneity study, which have implications in networks found across biology, ecology, and economy; so, adjacency sequence (AS) and fundamental sequences (FS) of regular vague graphs (RVGs) are defined with examples. One essential and adequate prerequisite has been ascribed to a VG with maximum four vertices is that it should be regular based on the adjacency sequences concept. Likewise, it is described that if ζ and its principal crisp graph (CG) are regular, then all the nodes do not have to have the similar AS. In the following, we obtain a characterization of vague detour (VD) g-eccentric node, and the concepts of vague detour g-boundary nodes and vague detour g-interior nodes in a VG are examined. Finally, an application of vague detour g-distance in transportation systems is given.


2017 ◽  
Vol 13 (4) ◽  
pp. 576-580
Author(s):  
Ibrahim Gambo ◽  
Nor Haniza Sarmin ◽  
Hidayat Ullah Khan ◽  
Muhammad Faiz Khan

The advancement in the fascinating area of fuzzy set theory has become area of much interest, generalization of the existing fuzzy subsystems of other algebraic structures is very important to tackle more current real life problems. In this paper, we give more generalized form of regular ordered gamma semigroups in terms of (E,EVq_k)-fuzzy gamma ideals. Particularly, we characterized left regular, right regular, simple and completely regular ordered gamma semigroups in terms of this new notion. Some necessary and sufficient conditions for ordered gamma semigroup to be completely regular are provided in this paper.


1991 ◽  
Vol 46 (7) ◽  
pp. 642-644 ◽  
Author(s):  
R. Stoop ◽  
J. Parisi ◽  
H. Brauchli

Different aspects of the scaling behavior of a dissipative dynamical system arc obtained in a straightforward way from the associated generalized entropy function which, in this way, embodies the relevant information on the scaling behavior of the system. This is demonstrated by the application of the thermodynamic formalism to two model systems for each of which, however, a specific numerical approach must be followed in order to overcome the numerical problems.


1970 ◽  
Author(s):  
Matisyohu Weisenberg ◽  
Carl Eisdorfer ◽  
C. Richard Fletcher ◽  
Murray Wexler

2021 ◽  
Vol 11 (11) ◽  
pp. 4757
Author(s):  
Aleksandra Bączkiewicz ◽  
Jarosław Wątróbski ◽  
Wojciech Sałabun ◽  
Joanna Kołodziejczyk

Artificial Neural Networks (ANNs) have proven to be a powerful tool for solving a wide variety of real-life problems. The possibility of using them for forecasting phenomena occurring in nature, especially weather indicators, has been widely discussed. However, the various areas of the world differ in terms of their difficulty and ability in preparing accurate weather forecasts. Poland lies in a zone with a moderate transition climate, which is characterized by seasonality and the inflow of many types of air masses from different directions, which, combined with the compound terrain, causes climate variability and makes it difficult to accurately predict the weather. For this reason, it is necessary to adapt the model to the prediction of weather conditions and verify its effectiveness on real data. The principal aim of this study is to present the use of a regressive model based on a unidirectional multilayer neural network, also called a Multilayer Perceptron (MLP), to predict selected weather indicators for the city of Szczecin in Poland. The forecast of the model we implemented was effective in determining the daily parameters at 96% compliance with the actual measurements for the prediction of the minimum and maximum temperature for the next day and 83.27% for the prediction of atmospheric pressure.


2021 ◽  
Vol 13 (6) ◽  
pp. 3465
Author(s):  
Jordi Colomer ◽  
Dolors Cañabate ◽  
Brigita Stanikūnienė ◽  
Remigijus Bubnys

In the face of today’s global challenges, the practice and theory of contemporary education inevitably focuses on developing the competences that help individuals to find meaningfulness in their societal and professional life, to understand the impact of local actions on global processes and to enable them to solve real-life problems [...]


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Oluchi Aroh ◽  
Kenneth M. Halanych

Abstract Background Long Terminal Repeat retrotransposons (LTR retrotransposons) are mobile genetic elements composed of a few genes between terminal repeats and, in some cases, can comprise over half of a genome’s content. Available data on LTR retrotransposons have facilitated comparative studies and provided insight on genome evolution. However, data are biased to model systems and marine organisms, including annelids, have been underrepresented in transposable elements studies. Here, we focus on genome of Lamellibrachia luymesi, a vestimentiferan tubeworm from deep-sea hydrocarbon seeps, to gain knowledge of LTR retrotransposons in a deep-sea annelid. Results We characterized LTR retrotransposons present in the genome of L. luymesi using bioinformatic approaches and found that intact LTR retrotransposons makes up about 0.1% of L. luymesi genome. Previous characterization of the genome has shown that this tubeworm hosts several known LTR-retrotransposons. Here we describe and classify LTR retrotransposons in L. luymesi as within the Gypsy, Copia and Bel-pao superfamilies. Although, many elements fell within already recognized families (e.g., Mag, CSRN1), others formed clades distinct from previously recognized families within these superfamilies. However, approximately 19% (41) of recovered elements could not be classified. Gypsy elements were the most abundant while only 2 Copia and 2 Bel-pao elements were present. In addition, analysis of insertion times indicated that several LTR-retrotransposons were recently transposed into the genome of L. luymesi, these elements had identical LTR’s raising possibility of recent or ongoing retrotransposon activity. Conclusions Our analysis contributes to knowledge on diversity of LTR-retrotransposons in marine settings and also serves as an important step to assist our understanding of the potential role of retroelements in marine organisms. We find that many LTR retrotransposons, which have been inserted in the last few million years, are similar to those found in terrestrial model species. However, several new groups of LTR retrotransposons were discovered suggesting that the representation of LTR retrotransposons may be different in marine settings. Further study would improve understanding of the diversity of retrotransposons across animal groups and environments.


Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1242
Author(s):  
Ramandeep Behl ◽  
Sonia Bhalla ◽  
Eulalia Martínez ◽  
Majed Aali Alsulami

There is no doubt that the fourth-order King’s family is one of the important ones among its counterparts. However, it has two major problems: the first one is the calculation of the first-order derivative; secondly, it has a linear order of convergence in the case of multiple roots. In order to improve these complications, we suggested a new King’s family of iterative methods. The main features of our scheme are the optimal convergence order, being free from derivatives, and working for multiple roots (m≥2). In addition, we proposed a main theorem that illustrated the fourth order of convergence. It also satisfied the optimal Kung–Traub conjecture of iterative methods without memory. We compared our scheme with the latest iterative methods of the same order of convergence on several real-life problems. In accordance with the computational results, we concluded that our method showed superior behavior compared to the existing methods.


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