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Found 6289 publications

Magnet losses of fractional number slots per pole PMSM in flux weakening operation

I. Szenasy

Publication Name: Proceedings of the International Conference on Power Electronics and Drive Systems

Publication Date: 2013-08-01

Volume: Unknown

Issue: Unknown

Page Range: 761-766

Description:

An applied control the PMSM is the flux weakening operation for extending the region over nominal speed but on nominal voltage. This paper deals with these questions and its impacts. The proved method is increasing the torque angle and with this the d axis directed component of the stator current vector for reduce the main flux, but the loss developing in magnets became significant. These impacts and its reduction need several investigations. Our work indicates the possibilities and limits of flux-weakening for a given PMSM, and a usable control strategy. © 2013 IEEE.

Open Access: Yes

DOI: 10.1109/PEDS.2013.6527119

Modeling laterally loaded piles

János Szép

Publication Name: Pollack Periodica

Publication Date: 2013-08-01

Volume: 8

Issue: 2

Page Range: 117-129

Description:

Single row pile groups are gaining popularity as foundation system for both buildings and bridges. They are a reasonable and economical solutions for structures with low vertical loads e.g. bridge abutments. The lateral resistance of a pile group is the result of contact pressure between the individual pile shafts and the soil. When designing this kind of structure, the estimation of displacements and bending moments is the main focus of the calculation. In most cases single piles are modeled by assuming a Winkler material. For their calculations, designers typically employ one of the commonly-used structural FEM codes (e.g. AxisVM, Fem-Design). On the other hand, advanced, truly 3D FEM packages (like MIDAS GTS, Plaxis 3D) are available, allowing for realistic modeling of the soil environment and soil-structure interaction. As an intermediate solution, packages based on traditional approaches are also available (GEO5, CGU). In this paper, results obtained using three different calculation methods and packages are compared.

Open Access: Yes

DOI: 10.1556/Pollack.8.2013.2.13

Special problems of interaction between railway track and bridge

Zoltán Major

Publication Name: Pollack Periodica

Publication Date: 2013-08-01

Volume: 8

Issue: 2

Page Range: 97-106

Description:

This paper deals with the phenomenon of track-bridge interaction in railway bridges. Due to the continuity of the rails on the structural expansion joints, the deformations of the deck might induce stresses in the rails that need to be checked. The main design criteria are now specified in Eurocode 1-2.

Open Access: Yes

DOI: 10.1556/Pollack.8.2013.2.11

Hydrological study of the Aggtelek karst springs

Katalin Bene Róbert Koch Geza Hajnal

Publication Name: Pollack Periodica

Publication Date: 2013-08-01

Volume: 8

Issue: 2

Page Range: 107-116

Description:

Increased population growth and changing environmental conditions have focused attention on sustainability of karst spring flow. In Hungary, the quality of karst springs is acceptable for drinking water supply; the only treatment it needs is the disinfection. Aggtelek is one of the best-studied karst regions; a hydrologic monitoring network was built and operated at the Jósvafo Research Station for about 50 years. The long-term data for the 15 major karst springs, rainfall, and temperature was available for analyses. This paper presents a methodology to estimate karst spring recharge, which can then be adapted to predict karst spring flow in lessstudied areas.

Open Access: Yes

DOI: 10.1556/Pollack.8.2013.2.12

A regularized Method of Fundamental Solutions without desingularization

Csaba Gáspár

Publication Name: CMES Computer Modeling in Engineering and Sciences

Publication Date: 2013-07-30

Volume: 92

Issue: 1

Page Range: 103-121

Description:

Some regularized versions of the Method of Fundamental Solutions are investigated. The problem of singularity of the applied method is circumvented in various ways using truncated or modified fundamental solutions, or higher order fundamental solutions which are continuous at the origin. For pure Dirichlet problems, these techniques seem to be applicable without special additional tools. In the presence of Neumann boundary condition, however, they need some desingularization techniques to eliminate the appearing strong singularity. Using fundamental solutions concentrated to lines instead of points, the desingularization can be omitted. The method is illustrated via numerical examples. Copyright © 2013 Tech Science Press.

Open Access: Yes

DOI: DOI not available

A regularized Method of Fundamental Solutions without desingularization

No authors available

Publication Name: CMES - Computer Modeling in Engineering and Sciences

Publication Date: 2013-07-30

Volume: 92

Issue: 1

Page Range: 103-121

Description:

Some regularized versions of the Method of Fundamental Solutions are investigated. The problem of singularity of the applied method is circumvented in various ways using truncated or modified fundamental solutions, or higher order fundamental solutions which are continuous at the origin. For pure Dirichlet problems, these techniques seem to be applicable without special additional tools. In the presence of Neumann boundary condition, however, they need some desingularization techniques to eliminate the appearing strong singularity. Using fundamental solutions concentrated to lines instead of points, the desingularization can be omitted. The method is illustrated via numerical examples. Copyright © 2013 Tech Science Press.

Open Access: No

DOI: DOI not available

Stability analysis and design of a class of MIMO fuzzy control systems

Claudiu Radu Pozna Marius L. Tomescu Emil M. PETRIU Radu Emil Precup Stefan Preitl János Fodor

Publication Name: Journal of Intelligent and Fuzzy Systems

Publication Date: 2013-07-18

Volume: 25

Issue: 1

Page Range: 145-155

Description:

This paper presents a new stability analysis method dedicated to a class of fuzzy control systems (FCSs) controlling multi input-multi output (MIMO) nonlinear processes by means of Takagi-Sugeno-Kang fuzzy logic controllers (FLCs). The stability analysis of the FCSs is carried out using LaSalle's global invariant set theorem by the separate stability analysis of each fuzzy rule in MIMO fuzzy control systems. Therefore the complexity of the stability analysis is reduced and the adding of new fuzzy rules can be conducted easily; this modification of FLC structure requires the fulfillment of only one of the conditions of the stability analysis theorem suggested in this paper. Another advantage of the stability analysis approach proposed in this paper is that the derivative of the Lyapunov function candidate must be only negative semi-definite in comparison with Lyapunov's stability theorem where it must be negative definite. The conservativeness of stability conditions is thus reduced, and this enables the convenient design of FLCs. The applicability and efficiency of the theoretical results are illustrated by numerical simulations for a representative MIMO process which deals with the level control in a three spherical tank system. © 2013-IOS Press and the authors. All rights reserved.

Open Access: Yes

DOI: 10.3233/IFS-2012-0621

Analysis of the wear behavior of combustion engine components using radionuclide-technique

Mathias Roman Dreyer Wolfgang Optatzy Tamás Gergye Bernhard Kehrwald

Publication Name: Lecture Notes in Electrical Engineering

Publication Date: 2013-07-04

Volume: 189 LNEE

Issue: VOL. 1

Page Range: 171-181

Description:

The aim of this study is the analysis of wear behaviour of a timing chain in real engine operation in terms of the influence of variable operating parameters. Further experiments were carried out with used motor oil. During the wear measurements could be seen, that the variation of the oil temperature showed a minor effect on the wear behaviour. However the use of aged oil showed a significant change of the wear behaviour. This means, that in the design of chain drive systems and oil change intervals this correlation has to be considered for maintaining the targeted engine life. Fundamental experiments on a tribometer using different types of carbon black oil will help to describe this phenomena more accurately. © 2013 Springer-Verlag Berlin Heidelberg.

Open Access: Yes

DOI: 10.1007/978-3-642-33841-0_13

Basque identity and soccer

Róbert Győri Szabó

Publication Name: Soccer and Society

Publication Date: 2013-07-01

Volume: 14

Issue: 4

Page Range: 525-547

Description:

Football is regarded as one of the defining elements of the local national identity in Spain - a country with diverse historical nationalities. The game serves as the means for a nationality to dissociate from the majority-controlled state. The importance of national identities to be found on the territory of Spain is central to any worthy understanding of the history of football up to the present day, and it is especially true in the case of Basque football. Sport, and especially football, plays an important role in emphasizing the Basque national identity in all the Basque regions, and it is a special manifestation of their political beliefs. As this essay tries to argue, the game has become an integral part of Basque national culture while the football clubs and national teams have assumed political importance. The Basques have their own national teams, i.e. clubs, whose teams represent the Basque nation as also the country Euskadi. Thus, the essay aims to examine the relationships between football and Basque national identity in a historical perspective. © 2013 Copyright Taylor and Francis Group, LLC.

Open Access: Yes

DOI: 10.1080/14660970.2013.810434