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Found 5157 publications

Novel communication services based on ENUM technology

F. Hatwágner T. Heckenast Á Varga N. Varjasi Balázs Benyó K. Kovács

Publication Name: Ines 05 IEEE 9th International Conference on Intelligent Engineering Systems Proceedings

Publication Date: 2005-01-01

Volume: 2005

Issue: Unknown

Page Range: 217-220

Description:

ENUM is the short name for a protocol for connecting resources of telecommunication and the Internet to one another. It specifies a rule that makes it possible to relate a domain to a telephone number without any risk of ambiguity. This domain can then be used to identify various communication services like fax, mobile radio, voice-mail systems, e-mail addresses, IP telephony addresses, web pages, GPS coordinates, call diverts or unified messaging. Several countries in the world examine the possibilities of the use of ENUM in national trials. Recently two Hungarian universities and an Internet service provider established a research project aiming the development of ENUM based communication services. In Hungary we have to deal not only with the questions of creating and providing the technological background, but also with the business aspects of ENUM based service development. The article will firstly give an overview about the ENUM itself. Then it will deal with ENUM services and business models. After that we discuss the situation of ENUM in different European countries. It will present the planned and accomplished ENUM based services in these countries. Then we are going to give the aims of the project in Hungary, which is led by the Szechenyi Istvan University in Gy6r. In setting these aims we can rely on the projects of other countries, and learn from them. © 2005 IEEE.

Open Access: Yes

DOI: 10.1109/INES.2005.1555160

Classification of time series using singular values and wavelet subband analysis with ANN and SVM classifiers

Balázs Benyó P. Somogyi Péter Várady B. Paláncz

Publication Name: Ines 05 IEEE 9th International Conference on Intelligent Engineering Systems Proceedings

Publication Date: 2005-01-01

Volume: 2005

Issue: Unknown

Page Range: 239-243

Description:

Oscillation of the cerebral blood flow (CBF) is a common feature in several physiological or pathophysiological states of the brain. It is promising to identify the disorders of the cerebral circulation based on the classification of CBF signals. In order to distinguish between different physiological states, two different classification methods have been developed; a Radial Basis Function based Neural Network and a Support Vector Classifier with Gaussian kernel. In order to describe the temporal blood flow patterns, two feature extraction procedures were applied; spectral matrix and wavelet subband analysis. These feature extraction and classification methods are evaluated and their efficiencies are compared. The computations were carried out with Mathematica 5.1 and its Wavelet Application. © 2005 IEEE.

Open Access: Yes

DOI: 10.1109/INES.2005.1555165

Simulation of phase transformations in steel parts produced by laser powder deposition

L. Costa A. M. Deus I. Felde R. Colaço T. Reti R. Vilar

Publication Name: Materials Science Forum

Publication Date: 2005-01-01

Volume: 473-474

Issue: Unknown

Page Range: 315-320

Description:

Multilayer laser powder deposition is being used for the rapid manufacturing of fully dense near net shape components in a wide variety of materials. In this process parts are built by overlapping consecutive layers of a laser melted material. As a result of this overlapping, the material in each layer will undergo successive thermal cycles as new layers are deposited. Despite their short duration, these thermal cycles can activate solid-state transformations that lead to progressive modification of the microstructure and properties of the material. Since the thermal history of the material in the deposited part will differ from point to point, the part will present a complex and heterogeneous microstructure, and properties that differ from point to point. Given that the microstructure and property distribution in steel parts produced by laser powder deposition can only be predicted by modelling, a three-dimensional thermo-kinetic finite element model of laser powder deposition of tool steels was developed, In the present work this model was applied to the study of the influence of substrate size on the microstructure and properties of a six-layer wall of AISI 420 tool steel. The results show that the temperature field depends significantly on the size of the substrate, leading to distinct microstructures and properties in the final part. © 2005 Trans Tech Publications, Switzerland.

Open Access: Yes

DOI: 10.4028/0-87849-957-1.315

Implicit extension of taylor series method for initial value problems

G. Molnárka

Publication Name: Journal of Computational Methods in Sciences and Engineering

Publication Date: 2005-01-01

Volume: 5

Issue: 4

Page Range: 263-270

Description:

The Taylor series method is one of the earliest analytic-numeric algorithms for approximate solution of initial value problems for ordinary differential equations. The main idea of the rehabilitation of these algorithms is based on the approximate calculation of higher derivatives using well-known technique for the partial differential equations. The approximate solution is given as a piecewise polynomial function defined on the subintervals of the whole interval. This property offers different facility for adaptive error control. This paper describes several explicit Taylor series with implicit extension algorithms and examines its consistency and stability properties. The implicit extension based on a collocation term added to the explicit truncated Taylor series. This idea is different from the general collocation method construction, which conduces to the implicit R-K algorithms [12]. It demonstrates some numerical test results for stiff systems herewith we attempt to prove the efficiency of these new-old algorithms.

Open Access: Yes

DOI: 10.3233/jcm-2005-5404

Energy conservative algorithm for numerical solution of ODEs initial value problems

E. Miletics

Publication Name: Journal of Computational Methods in Sciences and Engineering

Publication Date: 2005-01-01

Volume: 5

Issue: 1

Page Range: 39-45

Description:

The numerical treatment of the ODE initial value problems is an intensively researched field. Recently the qualitative algorithms, such as monotonicity and positivity preserving algorithms are in the focus of investigation. For the dynamical systems the energy conservative algorithms are very important. In the case of Hamiltonian system the symplectic algorithms are very effective. This kind of algorithm is not adaptive, but doubtless they are powerful. The high-efficiency computers and the computer algebraic software systems allow us to create efficient adaptive energy conservative numerical algorithm for solving ODE initial value problems. In this article an adaptive numerical-analytical algorithm is suggested which very effectively can be applied for Hamiltonian systems, but the idea of construction can be adaptable for other initial value problems too, where there are some quantity preserved in time. The idea and the efficiency of the proposed algorithm will be presented by simple examples, such as the Lotka-Volterra and linear oscillator problems.

Open Access: Yes

DOI: 10.3233/jcm-2005-5104

Partial electron beam hardening of cast iron camshafts

Ágnes Csizmazia Miklós Horváth István Oláh T. Reti

Publication Name: Materials Science Forum

Publication Date: 2005-01-01

Volume: 473-474

Issue: Unknown

Page Range: 447-452

Description:

In order to improve the local surface properties (hardness, wear and contact fatigue resistance) of cast iron camshafts, detailed experiments with partial electron beam hardening have been performed. It was found that the required case depth of 0.3-0.5 mm and surface hardness of 600-700 HV can be achieved by using appropriately selected, computer-controlled processing parameters (angular speed, specific energy input, beam deflection). © 2005 Trans Tech Publications, Switzerland.

Open Access: Yes

DOI: 10.4028/0-87849-957-1.447

Speeding up the performance analysis of communication systems

Gábor Lencse

Publication Name: 2005 European Simulation and Modelling Conference Esm 2005 Proceedings

Publication Date: 2005-01-01

Volume: Unknown

Issue: Unknown

Page Range: 329-333

Description:

The methods for the performance analysis of communication networks are reviewed. Different ways are shown how the combination of DES and TFA can be made faster by using parallelism. An efficient algorithm for the parallel execution of the combined DES and TFA is presented.

Open Access: Yes

DOI: DOI not available

The impact of stray currents of electric traction over the environment

Zoltán Puklus József Lingvay Lászlo Hodossy

Publication Name: Korrozios Figyelo

Publication Date: 2005-01-01

Volume: 45

Issue: 2

Page Range: 43-48

Description:

No description provided

Open Access: Yes

DOI: DOI not available

Characterization of cerebral blood flow oscillations using different classification methods

Balázs Benyó P. Somogyi Zoltán Benyó B. Paláncz

Publication Name: IFAC Proceedings Volumes IFAC Papersonline

Publication Date: 2005-01-01

Volume: 16

Issue: Unknown

Page Range: 214-219

Description:

Oscillation of the cerebral blood flow (CBF) is a common feature in several physiological or pathophysiological states of the brain. It is a promising opportunity to identify the disorders of the cerebral circulation based on the classification of CBF signals. Three classification models are developed with different heuristic in order to carry out the systematic classification based on a problem specific feature extraction. The efficiency of the selected classification methods are evaluated and compared. Copyright © 2005 IFAC.

Open Access: Yes

DOI: 10.3182/20050703-6-cz-1902.02150