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The dual choice of geodetic horizontal reference systems for Ukraine

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Geodesy and Geodynamics 2023年第3期14卷 254-264页

作者： Elena novikova alena Palamar Rostyslav Lopunov Department of Geodesy State Higher Educational InstitutionKryvyi Rih National UniversityKryvyi RihUkraine

Almost all European countries use at least two horizontal reference systems, which allow them to minimize all risks when changing the coordinate system. The first system is used for the needs of the national survey in general, and also for technical applications in engineering surveys. A brief description of this system can be written by the formula: Geocentric Ellipsoid(GRS80) + Projection(UTM). More than half of the European countries for the second national systems use the GRS80 geocentric ellipsoid together with a projection other than UTM, some of them continue to use the projection of the old coordinate systems. The rest of the countries, excluding Ukraine, adapted the existing national coordinate systems to modern requirements, removing deformations from them concerning the ETRS89. A small number of European countries have implemented the GRS80 geocentric ellipsoid together with the UTM projection for cadastral surveys and topographic maps with a scale of 1:5000 and larger. Only one country, Ukraine, chose a variant for the new coordinate system(UCS2000), which is briefly written by the formula: Old Not Geocentric Ellipsoid + New Projection. The analysis of modern coordinate systems of Europe made it possible to formulate two variants of the future coordinate system of Ukraine based on a geocentric ellipsoid. It is shown that the transition to a geocentric ellipsoid will change the coordinates and heights of the points, but practically will not change the distance between the points and the area of the parcels.

关键词： UTM GRS80 Projection parameters Quantitative characteristics of land parcels UCS2000

A novel method for investigation of acoustic and elastic wave phenomena using numerical experiments

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Theoretical & Applied Mechanics Letters 2020年第5期10卷 307-314页

作者： alena Favorskaya Igor Petrov Moscow Institute of Physics and Technology DolgoprudnyMoscow regionRussian Federation Scientific Research Institute for System Analysis of the Russian Academy of Sciences MoscowRussian Federation Xi'an Jiaotong University Xi'an 710049China

The emergence of new types of composite materials,the depletion of existing hydrocarbon deposits,and the increase in the speed of trains require the development of new research methods based on wave ***,it is necessary to determine the laws of wave scattering in inhomogeneous *** propose a method that combines the advantages of a numerical simulation with an analytical study of the boundary value problem of elastic and acoustic wave *** this letter we present the results of the study using the proposed method:the formation of a response from a shear wave in an acoustic medium and the formation of shear waves when a vertically incident longitudinal wave is scattered by a vertical gas-filled *** have obtained a number of analytical expressions characterising the scattering of these wave types.

关键词： Elastic waves Acoustic waves Waves scattering Fractures Seismic prospecting

Links Between HX-Groups and Hypergroups

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Algebra Colloquium 2021年第3期28卷 441-452页

作者： Irina Cristea Michal novák Babatunde Oluwaseun Onasanya Centre for Information Technologies and Applied Mathematics University of nova Gorica Slovenia Faculty of Electrical Engineering and Communication Brno University of Technology Czech Republic Key Laboratory of Intelligent Information Processing and Control of Chongqing Municipal Institutions of Higher Education Chongqing Three Gorges University Chongqing 404000China Department of Mathematics University of IbadanNigeria

The concept of an HX-group is an upgrade of the concept of a group,in which a new operation is defined on the family of non-empty subsets of a *** this new support set together with the new operation is a group,then we call it an *** the other hand,a hyperoperation is a mapping having the same codomain as the operation of an HX-group,i.e.,the family of non-empty subsets of the initial set,but a different domain-the set *** could be(and was indeed)a source of confusion,which is clarified in this ***,HX-groups naturally lead to constructions of *** links between these two algebraic concepts are presented,with the aim of reviving the old notion of an HX-group in the current research on algebraic *** of such existing links and one newly established link are also discussed.

关键词： HX-group hyperstructure theory Chinese hypergroupoid EL-hyperstructure power set

Harmonics in the Squirrel Cage Induction Motor Analytic Calculation Part III: Influence on the Torque-speed Characteristic

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 86-102页

作者： G.kovács the Ganz Electric Works BudapestHungary

The harmonics that appear in the squirrel cage asynchronous machine have been discussed in great detail in the literature for a long time. However, the systematization of the phenomenon is still pending, so we made an attempt to fill this gap in the previous parts of our study by elaborating formulas for calculation of parasitic torques. It was a general demand among those who work in this field towards the author to verify his formulas with measurements. In the literature, it seems,only one detailed, purposeful series of measurements has been published so far, the purpose of which was to investigate the effect of the number of rotor slots on the torque-speed characteristic curve of the machine. The main goal of this study is to verify the correctness of the formulas by comparing them with the referred series of measurements. Relying on this, the expected synchronous parasitic torques were developed for the frequently used rotor slot numbers-as a design guide for the ***, together with our complete table for radial magnetic pull published in our previous work, the designer has all the principles, data and formulas available for the right number of rotor slots for his given machine and for the drive system. This brings this series of papers to an end.

关键词： Asynchronous parasitic torques Induction motor Squirrel cage rotor Space harmonics Synchronous parasitic torques

Harmonics in the Squirrel Cage Induction Motor Analytic Calculation-Part Ⅰ: Differential Leakage, Attenuation, Asynchronous Parasitic Torques

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CES Transactions on Electrical Machines and Systems 2023年第4期7卷 320-329页

作者： G.kovács Ganz Electric Works 1095 BudapestHungary

The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field, as well as the related differential leakage, attenuation, asynchronous parasitic torques have been discussed in great detail in the literature, but always separately, for a long time. However, systematization of the phenomenon still awaits. Therefore, it is worth summarizing the completeness of the phenomena in a single study – with a new approach at the same time-in order to reveal the relationships between them. The role of rotor slot number is emphasized much more than before. An existing, commonly used, but still impractical basic figure has been modified to more clearly demonstrate the response of the rotor for the harmonics of the stator. The need to treat differential leakage, asynchronous parasitic torques and attenuation together will be demonstrated: new formula for asynchronous parasitic torque is derived;the long-used characteristic curves for differential leakage and attenuation used separately so far was merged into one, correct curve in order to provide a correct design guide for the engineers.

关键词： Asynchronous parasitic torque Attenuation Differential leakage Squirrel cage induction motor Winding harmonics

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Organelle Extensions in Plant Cells

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Journal of Integrative Plant Biology 2012年第11期54卷 851-867页

作者： Jaideep Mathur alena Mammone Kiah A.Barton Laboratory of Plant Development and Interactions Department of Molecular and Cellular BiologyUniversity of Guelph50 Stone RoadGuelphOntario N1G 2W1Canada

Cell walls lock each cell in a specific position within the supraorganization of a plant. Despite its fixed location, each cell must be able to sense alterations in its immediate environment and respond rapidly to ens... 详细信息

关键词： Organelle extensions stromules peroxules fluorescent proteins homeostasis.

Determining the Relative Age of Fault Activity through Analyses of Gouge Mineralogy and Geochemistry: A Case Study from Vápenná(Rychleby Mts), Czech Republic

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International Journal of Geosciences 2010年第2期1卷 66-69页

作者： Lucie nováková Pavel Hájek Martin Stastny 不详

The relative age of fractures can be determined through structural analyses in the field or through the detailed mineralogical (XRD) and chemical analyses (AAS method, volumetric, and gravimetric analysis) of fault gouge in the laboratory. The aim of this work was to compare these approaches. It was hypothesised that the two methods would yield consistent results. The studied faults were located in the Rychleby Mts, part of the Sudetic Marginal Fault Zone. The relative age of the faults was determined in the field through the application of the intersection law. The fault gouges were sampled in a crystalline limestone quarry near the village of Vápenná. The mineralogical composition of the fault gouges has been established by XRD analysis of powder samples and analysis of preferentially oriented clay minerals. From our result, it is clear that these two approaches yielded consistent results with regard to the relative age of the faults.

关键词： Crystalline Limestone Intersecting Faults Fault Gouge Relative Chronology

Defect aggregates in the Sr_2MgSi_2O_7 persistent luminescence material

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Journal of Rare Earths 2011年第12期29卷 1130-1136页

作者： Jorma Hls Taneli Laamanen Mika Lastusaari Pavel novák Department of Chemistry University of Turku Turku University Centre for Materials and Surfaces(MatSurf) Graduate School of Materials Research(GSMR) Institute of Physics Academy of Sciences of the Czech Republic

The crystal and electronic structure of the Eu^2＋ doped and defect containing Sr2MgSi2O7 persistent luminescence material were studied using the density functional theory （DFT）. The defects may act as energy storage or even luminescence quenching centres in these materials, however their role is very difficult to confirm experimentally. The probability of vacancy formation was studied using the total energy of the defect containing host. Significant structural modifications in the environment of the isolated defects, especially the strontium vacancy, as well as defect aggregates were found. The experimental band gap energy of Sr2MgSi2O7 was well reproduced by the calculations. The defect induced electron traps close to the host＇s conduction band were found to act as energy storage sites contributing to its efficient persistent luminescence. The interactions between the defects were found to modify both the Eu^2＋ 4f^7 ground state energy as well as the trap structure. The effect of charge compensation induced by the rare earth co-doping on the defect structure and energy storage properties of the persistent luminescence materials was discussed.

关键词： strontium magnesium disilicate vacancy defect aggregate persistent luminescence density functional theory calculations rare earths

Robustness evaluation of cutting tool maintenance planning for soft ground tunneling projects

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Underground Space 2018年第1期3卷 72-85页

作者： alena Conrads Markus Scheffer Markus Konig Markus Thewes Inastitute of Tunneling cand Construction Management Ruhr-Universitat BochunGermany Chair of Computing in Engineering Ruhr-Universitit BochunGermany

Tunnel boring machines require extensive maintenance and inspection effort to provide a high *** cutting tools of the cutting wheel must be changed timely upon reaching a critical *** one possible maintenance strategy is to change tools only when it is absolutely necessary,tools can also be changed preventively to avoid further *** different maintenance strategies inﬂuence the maintenance duration and the overall project ***,determine downtime related to a particular mainte-nance strategy is still a challenging *** paper shows an analysis of the robustness to achieve the planned project performance of a maintenance strategy considering uncertainties of wear behavior of the cutting tools.A simulation based analysis is presented,imple-menting an empirical wear prediction *** strategies of maintenance planning are compared by performing a parameter vari-ation study including Monte-Carlo *** maintenance costs are calculated and evaluated with respect to their ***,an improved and robust maintenance strategy has been determined.

关键词： Mechanized tunneling,Maintenance Wear of cutting tools Process simulation Robustness Uncertainty modeling