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Author(s):  
Andrey M. Karpachevskiy ◽  
Oksana G. Filippova ◽  
Pavel E. Kargashin

In this paper, we describe an experiment of complex power grid structure and wind and sleet mapping of territory using two different network indices: standard edge betweenness centrality and new author’s index – electrical grid centrality. Such analysis of the network allows to identify power lines with high load which could be vulnerable elements of the power grid. It is very important for strategic planning of power grids to reduce the risk of accidents by distributing loads across several lines so that they will be able to reserve each other. As a case territory for this research, we took the Ural united power system in Russia which is greatly exposed to different sleet and wind according to the statistics of the power grid operator. The degree of natural hazard consequences could be compensated by the network structure through alternative paths of energy supply or vice versa – increased if they are absent. At the same time, in this paper we consider that power grids have their own features from the graph theory point of view, for example multiple (parallel) edges, branches, different types of vertices. The existing index of edge betweenness centrality does not perfectly cope with them. We compare two indices characterizing power line importance within the system – betweenness centrality and electrical grid centrality and analyze the network structure features together with the spatial distribution of sleet and wind. As a result, we could identify bottlenecks in the study network. According to this study the most vulnerable power lines were detected, for example 500 kV Iriklinskaya CHP – Gazovaya and 500 kV Yuzhnouralskaya CHP-2 – Shagol power lines, that supply big cities such as Chelyabinsk and Orenburg and a bunch of industries around them.


2021 ◽  
Vol 11 (2) ◽  
pp. 30
Author(s):  
Mariana Yante Pereira

This paper aims at introducing some theoretical and first analytical reflections on the possible implications or directions that the Chinese foreign policy under the premises of Socialism with Chinese characteristics to Brazil could have in the agricultural sector. The underlying hypothesis it intends to explore is that, although incipient, the international trade on primary commodities, specifically on food, may offer room to reframe the implications that models such as the dependency theory point out as a challenge to balanced tradeoffs in the Latin American context. The theoretical analysis offers an initial approach to the interconnections between socialism's international political economy with Chinese characteristics and the Chinese South-South cooperation. Afterward, it places the debate in Brazil's peasantry movement by exploring its correlation with the agribusiness sector and food security, discussing threats and potentialities for alternatives to trade cooperation under a capitalist framework.


Universe ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 11
Author(s):  
Philippe Brax ◽  
Santiago Casas ◽  
Harry Desmond ◽  
Benjamin Elder

Long range scalar fields with a coupling to matter appear to violate known bounds on gravitation in the solar system and the laboratory. This is evaded thanks to screening mechanisms. In this short review, we shall present the various screening mechanisms from an effective field theory point of view. We then investigate how they can and will be tested in the laboratory and on astrophysical and cosmological scales.


enadakultura ◽  
2021 ◽  
Author(s):  
Gabriel Tagauri

Significant and important details should be taken into account when planning a Phonetics training course. As you know, the Morphology and Syntax of the Georgian language are taught in small doses at school, and thus, these subjects are somewhat familiar to the entrants. But we can not say the same about "Phonetics". This scientific discipline is a completely new fruit for first-year students of the Philology contingent, which puts lecturers in front of great responsibilities and serious difficulties. Thus, when working out a Phonetics lecture course, we must carefully select the issues that we will provide to students seeking new knowledge, not in terms of learning and mastery, but in terms of assessment and cognition. We hope that the model we have developed will give the freshman the opportunity to think rationally, to choose and to formulate his own position, even to identify/develop a new theory/point of view, and to create his scientific skills.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Karim Benakli ◽  
Carlo Branchina ◽  
Gaëtan Lafforgue-Marmet

Abstract Einstein-Maxwell-dilaton theory with non-trivial dilaton potential is known to admit asymptotically flat and (Anti-)de Sitter charged black hole solutions. We investigate the conditions for the presence of horizons as function of the parameters mass M, charge Q and dilaton coupling strength α. We observe that there is a value of α which separate two regions, one where the black hole is Reissner-Nordström-like from a region where it is Schwarzschild-like. We find that for de Sitter and small non-vanishing α, the extremal case is not reached by the solution. We also discuss the attractive or repulsive nature of the leading long distance interaction between two such black holes, or a test particle and one black hole, from a world-line effective field theory point of view. Finally, we discuss possible modifications of the Weak Gravity Conjecture in the presence of both a dilatonic coupling and a cosmological constant.


Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1999
Author(s):  
Diego Guadagnoli

This write-up aims at a comprehensive discussion of the status of the so-called B-anomalies, as well as their interpretation from an effective-theory point of view. The focus is on presenting facts and physics arguments using the bare minimum of equations and pointing instead to the relevant literature in each specific case.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Jia Tang ◽  
Feng Zhen ◽  
Xia Wang

Based on 898 English documents and 363 Chinese documents citing the Rising of Network Society, it studied that the knowledge contribution of citation content analysis and citation context analysis methods, and the knowledge contribution of Chinese and foreign quotations to human geography. The study found that “mobile space” is the most quoted theoretical view in domestic and foreign literature, and the proportion of domestic research is significantly higher than foreign research; the focus of domestic and foreign research focuses on the external spatial form and its transformation, while foreign research pays more attention on the internal spatial dynamics of network society and three types of knowledge contributions, reflecting the influence of “network social theory” on human geography. Among them, critical references reveal the shortcomings of “network social theory” point out the abstraction of “spatial duality” the importance of local space, and the limitations of research data, methods, and time background, which provides new enlightenment for the future application and innovation of “network social theory” in the field of human geography.


Mathematics ◽  
2021 ◽  
Vol 9 (18) ◽  
pp. 2340
Author(s):  
Svetoslav G. Nikolov ◽  
Vassil M. Vassilev

In this paper, the non-linear dynamical behavior of a 3D autonomous dissipative system of Hopf–Langford type is investigated. Through the help of a mode transformation (as the system’s energy is included) it is shown that the 3D nonlinear system can be separated of two coupled subsystems in the master (drive)-slave (response) synchronization type. After that, based on the computing first and second Lyapunov values for master system, we have attempted to give a general framework (from bifurcation theory point of view) for understanding the structural stability and bifurcation behavior of original system. Moreover, a family of exact solutions of the master system is obtained and discussed. The effect of synchronization on the dynamic behavior of original system is also studied by numerical simulations.


Author(s):  
Gustavo Bodanza

F -systems are useful digraphs to model sentences that predicate the falsity of other sentences. Paradoxes like the Liar and the one of Yablo can be analyzed with that tool to find graph-theoretic patterns. In this paper we studied this general model consisting of a set of sentences and the binary relation ‘... affirms the falsity of...’ among them. The possible existence of non-referential sentences was also considered. To model the sets of all the sentences that can jointly be valued as true we introduced the notion of conglomerate, the existence of which guarantees the absence of paradox. Conglomerates also enabled us to characterize referential contradictions, i.e., sentences that can only be false under a classical valuation due to the interactions with other sentences in the model. A Kripke-style fixed-point characterization of groundedness was offered, and complete (meaning that every sentence is deemed either true or false) and consistent (meaning that no sentence is deemed true and false) fixed points were put in correspondence with conglomerates. Furthermore, argumentation frameworks are special cases of F -systems. We showed the relation between local conglomerates and admissible sets of arguments and argued about the usefulness of the concept for the argumentation theory.


Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1323
Author(s):  
Gabriel Bercu

The study of even functions is important from the symmetry theory point of view because their graphs are symmetrical to the Oy axis; therefore, it is essential to analyse the properties of even functions for x greater than 0. Since the functions involved in Wilker–Huygens-type inequalities are even, in our approach, we use cosine polynomials expansion method in order to provide new refinements of the above-mentioned inequalities.


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