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Number of results: 8
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Abstract

This article proposes an analytical model of a system with priorities servicing a mixture of different elastic traffic streams. The model presented in the article was developed as the extension of earlier works published by the authors. It utilizes the concept of equivalent bandwidth and then, following bandwidth discretization, uses the dependencies introduced on the basis of the assumptions adopted for the generalized Kaufman-Roberts formula and for the model of a full-availability group with traffic compression. The article presents a possibility of using the proposed model to model the radio interface in a multi-service mobile network and provides an example of the above with the interface of an LTE network. Since the proposed model is an approximate one, the results of the calculations are compared with the results of simulations. A comparison of the results confirms an acceptable level of accuracy of the model. The model can be successfully used in the analysis and design of links and nodes of telecommunication and computer networks.

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Authors and Affiliations

B. Nowak
ORCID: ORCID
M. Piechowiak
M. Stasiak
P. Zwierzykowski
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Abstract

The paper presents an estimation of liquefaction susceptibility of some soils from the coast of the Marmara Sea, which was heavily

striken by the Kocaeli earthquake in 1999. Firstly, the results of field investigations are summarized. Then, the results of laboratory investigations of physical and mechanical properties of the soils collated from the sites investigated are presented. The mechanical properties relate to the compaction/liquefaction model of saturated soils. This model is briefly outlined, then respective experimental procedures dealing with its calibration described, and values of material parameters listed. Liquefaction potential of investigated soils is analysed using standard procedures, based on the grain size distribution curves and SPTs. Finally, the simulation of pore-pressure generation and onset of liquefaction of Turkish soils is carried out, using the compaction/liquefaction model. Discussion of some standard empirical procedures of estimation of liquefaction potential of saturated soils, conducted from the analytical point of view, is also presented.

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Authors and Affiliations

A. Sawicki
W. Świdziński
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Abstract

A new expression is proposed to calculate the earth-energy of an earth-air-pipe heat exchanger during winter heating for three kinds of soil in France. An analytical model is obtained by using numerical computation developed in Scilab – a free open source software. The authors showed the comparison between their simple analytical model and experimental results. They showed the influence of different parameters to specify the size of the heat exchanger.

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Authors and Affiliations

Vincent M.F. Molcrette
Vincent A.R. Autier
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Abstract

The paper presents analytical relationships based on the theory of Green’s functions. The relationships refer to instantaneous and continuous as well as point and ring heat sources which are discussed. The relationship relating to continuous ring source is the basis for modelling and designing of spiral ground heat exchangers. Heat transfer in the infinite and semi-infinite body was considered. In the latter case, the image method was discussed. Using the results of measurements regarding heat transfer in the ground with a heat exchanger in the form of a single coil installed, a comparison of calculated ground temperatures with measured values was presented.

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Authors and Affiliations

Barbara Larwa
Krzysztof Kupiec
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Abstract

Vertical transport of wall-panels is a part of the prefabrication process of wood-framed buildings. The total dead weight of a wall is suspended on several lifting slings, pointwise clasping the top plate of the wall. This indicates, that all the weight of a wall is cumulated in sheathing-to-framing fasteners, usually staples. This article presents experimental investigations and analytical models evaluated for the description of light wood-framed walls in the process of lifting. Three different models cover the analytical approach: a model of a simple beam on elastic supports (BSS), a model of assembled beams (ACBS), three-dimensional (3D) spatial FE model of the wall (WFEM). Board-to-beam joint material parameters are determined on the base of experimental results. These connections are converted into two variants in the form of spring elements for 2D analysis, and beam elements for 3D analysis.
The numerical results exhibit that the proposed models may correctly represent behavior of a real wall in lifting, applying elastic materials parameters.
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Authors and Affiliations

Jarosław Malesza
1
Czesław Miedziałowski
1
ORCID: ORCID

  1. Bialystok University of Technology, Faculty of Civil Engineering and Environmental Sciences, Wiejska 45A, 15-351 Bialystok, Poland
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Abstract

Divorced eutectoid growth of cementite in AISI 1080 steel is investigated as a function of cooling rate for incomplete austenitization-based heat treatment. Furthermore, a fundamental mathematical relationship is established through analytical treatment that correlates divorced eutectoid growth with effective cooling rate and degree of undercooling in view of bulk diffusion controlled growth model. As the cooling rate increases, the divorced eutectoid growth of cementite is gradually ceased. The result predicted by the analytical model closely matches with the experimental result (%Deviation ≤ 7).

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Authors and Affiliations

Prasenjit Biswas
Joydeep Maity
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Abstract

In this paper, the authors present an extension of the scope of the previously conducted research to the full three-dimensional computer simulation (using the finite element method), which takes into account the interaction between: heavy caterpillar tracks system – working platform – weak subsoil. The article presents a computer model considering two caterpillars, resting on elastic-plastic sub-soil, with standard Mohr-Coulomb yield conditions, allowing for computer simulation of the behavior of the system up to achievement of ultimate limit state. The results of the above model are treated as the reference for a simplified Analytical Models of estimating the limit state, which might be used in design procedures. In turn, these Analytical Models are enhancements of previously presented one. The most important results concluding form the Analytical Model are simple interaction formulas, in the space of moments acting on the machine-subsoil system, limiting a domain of safety in given soil conditions.
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Authors and Affiliations

Aleksander Urbański
1
ORCID: ORCID
Mateusz Richter
2
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Environmental Engineering and Energy, ul. Warszawska 24, 31-155 Krakow, Poland
  2. University of Agriculture in Krakow, Department of Rural Building, Al. Mickiewicza 24/28, 59-130 Krakow, Poland
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Abstract

Dynamic characteristics for three types of railgun constructions were simulated and measured in this work. The simplest construction is the iron-less (IL) railgun, while the two other ones (IC and ICPM) have an iron-core. The iron-core permanent magnet (ICPM) railgun additionally has permanent magnets. To compare their characteristics, similar dimensions of the rails and iron cores were adopted, and the same power supply system was used. Numerical magnetic field analyses and our analytical models have been used to determine the electromagnetic parameters. They were verified experimentally. The transient states of the railguns were studied with our field-circuit mathematical model, and their results were also verified by experiments.
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Authors and Affiliations

Paweł Piekielny
1
ORCID: ORCID
Bronisław Tomczuk
1
ORCID: ORCID
Andrzej Waindok
1
ORCID: ORCID

  1. Department of Electrical Engineering and Mechatronics, Opole University of Technology, Prószkowska 76 str., 45-758 Opole, Poland

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