Search in Publications

Found 6278 publications

Investigation of the surface morphology on epitaxially grown fullerene structures

Ákos Nemcsics R. Adelung Imre Mojzes L. Kipp Szilvia Nagy S. Woedtke R. Schwedhelm

Publication Name: Vacuum

Publication Date: 2009-08-25

Volume: 84

Issue: 1

Page Range: 152-154

Description:

Fullerene layers molecular beam epitaxially grown on, a vanadium-selenide substrate are investigated and the morphology of the layered structures is studied. The individual layer morphologies are derived from the atomic force microscopy picture of the surface. The pattern morphology of certain layers is analyzed by a box counting method. The surface morphology shows fractal behaviour. The pattern of each layer shows different dimensions. The actual dimension depends on the actual distance of the layer from the substrate. The change of the dimension is attributed to the change of the binding behaviour. The topology of the surface is also studied using participation ratio and structural entropy calculations. © 2009 Elsevier Ltd. All rights reserved.

Open Access: Yes

DOI: 10.1016/j.vacuum.2009.04.060

Simulation of a developed magnetic flux leakage method

Miklós Kuczmann Gergely Kovács

Publication Name: Pollack Periodica

Publication Date: 2009-08-01

Volume: 4

Issue: 2

Page Range: 45-56

Description:

The paper presents the analysis of nondestructive testing equipment under investigation. There are two main parts of the research as well as this paper. The first part shows the present state of the developed nondestructive tester based on the Magnetic Flux Leakage method, the other part reviews the simulation and the results, which have been made with the principle of the Finite Element Method. The aim now is to define the order of magnitude of the magnetic flux density in the positions of the sensor.

Open Access: Yes

DOI: 10.1556/Pollack.4.2009.2.5

From individual memory to organizational memory (intelligence of organizations)

No authors available

Publication Name: World Academy of Science, Engineering and Technology

Publication Date: 2009-08-01

Volume: 56

Issue:

Page Range: 1-6

Description:

Intensive changes of environment and strong market competition have raised management of information and knowledge to the strategic level of companies. In a knowledge based economy only those organizations are capable of living which have up-to-date, special knowledge and they are able to exploit and develop it. Companies have to know what knowledge they have by taking a survey of organizational knowledge and they have to fix actual and additional knowledge in organizational memory. The question is how to identify, acquire, fix and use knowledge effectively. The paper will show that over and above the tools of information technology supporting acquisition, storage and use of information and organizational learning as well as knowledge coming into being as a result of it, fixing and storage of knowledge in the memory of a company play an important role in the intelligence of organizations and competitiveness of a company.

Open Access: No

DOI: DOI not available

Motional finite element simulation of a single-phase induction motor

Miklós Kuczmann Daniel Marcsa

Publication Name: Pollack Periodica

Publication Date: 2009-08-01

Volume: 4

Issue: 2

Page Range: 57-66

Description:

The paper deals with the analysis of the single-phase induction motor of Problem No. 30a of the COMPUMAG TEAM Workshop. The problem has been solved by the motional two-dimensional time-harmonic Finite Element Method (FEM) using different potential formulations, the A , V - A , -potential formulation and the T , Φ - Φ -potential formulation. Here the problem is a linear eddy current field problem.

Open Access: Yes

DOI: 10.1556/Pollack.4.2009.2.6

Nonlinear finite element method in magnetism

Miklós Kuczmann

Publication Name: Pollack Periodica

Publication Date: 2009-08-01

Volume: 4

Issue: 2

Page Range: 13-24

Description:

The paper presents and compares three potential formulations to solve nonlinear static magnetic field problems by applying the fixed-point technique and the Newton-Raphson scheme. Nonlinear characteristics have been handled by the polarization method in the two algorithms. The proposed combination of Newton-Raphson scheme and the polarization formulation result in a very effective nonlinear solver, because only the derivate of the characteristics, i.e. only the permeability or the reluctivity has to be used. That is why, this method can be prosperous to solve nonlinear problems with hysteresis, and it is faster than the classical fixed-point method.

Open Access: Yes

DOI: 10.1556/Pollack.4.2009.2.2

A new algorithm to determine optimal transfer opportunities in a public transport network

Agoston Winkler

Publication Name: Pollack Periodica

Publication Date: 2009-08-01

Volume: 4

Issue: 2

Page Range: 135-143

Description:

Transfer opportunities play an important role in modeling public transport networks. Finding the optimal transfer locations is essential for providing valuable passenger information in order to support journey planning. Furthermore, using this information makes possible to accelerate general-purpose shortest path algorithms, making transit assignments more efficient. However, determining optimal transfer opportunities in a dense network is not an easy task. This paper presents the principles of a possible solution, and a new algorithm based on them, illustrated with actual examples. The algorithm has a polynomial complexity; therefore it can be used easily in practice.

Open Access: Yes

DOI: 10.1556/Pollack.4.2009.2.14

From individual memory to organizational memory (intelligence of organizations)

Bencsik Andrea I. Marosi V. Lore

Publication Name: World Academy of Science Engineering and Technology

Publication Date: 2009-08-01

Volume: 56

Issue: Unknown

Page Range: 1-6

Description:

Intensive changes of environment and strong market competition have raised management of information and knowledge to the strategic level of companies. In a knowledge based economy only those organizations are capable of living which have up-to-date, special knowledge and they are able to exploit and develop it. Companies have to know what knowledge they have by taking a survey of organizational knowledge and they have to fix actual and additional knowledge in organizational memory. The question is how to identify, acquire, fix and use knowledge effectively. The paper will show that over and above the tools of information technology supporting acquisition, storage and use of information and organizational learning as well as knowledge coming into being as a result of it, fixing and storage of knowledge in the memory of a company play an important role in the intelligence of organizations and competitiveness of a company.

Open Access: Yes

DOI: DOI not available

Finite element simulation and development of a radio frequency inductor

Miklós Kuczmann Zoltán Pólik

Publication Name: Pollack Periodica

Publication Date: 2009-08-01

Volume: 4

Issue: 2

Page Range: 25-36

Description:

The design of inductors is not an easy and cheap task considering the dimensions, the nominal value of inductance, the quality factor and the impedance of the component. Before the beginning of manufacturing a new type of inductors, a lot of trial components have to produce, have to measure and have to try out. Finite element modeling is a well-tried process to examine engineering products before manufacturing them. To reduce the cost and the time of the design process, in the paper a finite element model has been built up to simulate inductors. In the paper the model is presented, which is able to simulate the important attributes of the component, for example the inductance, the impedance and the quality factor. The comparison of the experimental and the simulated attributes of the inductor will also be shown. By using the built up model the development possibilities of the inductor have been examined through the modification of the winding.

Open Access: Yes

DOI: 10.1556/Pollack.4.2009.2.3

Randomized, double-blind, placebo-controlled, proof-of-concept study of the cortical spreading depression inhibiting agent tonabersat in migraine prophylaxis

M. D. Ferrari P. J. Goadsby J. G. Mills Attila Csanyi J. Olesen

Publication Name: Cephalalgia

Publication Date: 2009-07-01

Volume: 29

Issue: 7

Page Range: 742-750

Description:

Tonabersat is a novel putative migraine prophylactic agent with an unique stereospecific binding site in the brain. Tonabersat has been shown, in animal models, to inhibit experimentally induced cortical spreading depression, the likely underlying mechanism for migraine aura, and cerebrovascular responses to trigeminal nerve stimulation. The aim was to study the potential for tonabersat as a migraine preventive. A randomized, double-blind, placebo-controlled, multicentre, parallel group study recruited patients with migraine with and without aura experiencing between two and six migraine attacks per month. After a 1-month baseline they received tonabersat 20 mg daily for 2 weeks and 40 mg daily for a further 10 weeks. The primary end-point was the change in mean number of migraine headache days between the third month and the baseline period in the intention-to-treat population comparing the placebo (n = 65) and tonabersat (n = 58) groups. At the primary end-point there was a 1.0-day (95% confidence interval -0.33, 2.39; P = 0.14) difference in reduction in migraine days between tonabersat and placebo. There were 10 secondary efficacy end-points, of which two were statistically significant. In month 3 of treatment, the responder rate, defined as a 50% reduction in migraine attacks, was 62% for tonabersat and 45% for placebo (P < 0.05), and the rescue medication use was reduced in the tonabersat group compared with placebo by 1.8 days (P = 0.02). Placebo responses were particularly high for all end-points. At least one treatment-emergent adverse event was reported in the tonabersat group in 61% of patients compared with 51% in the placebo group; none was worrisome. Placebo responses were unexpectedly high in this trial, complicating straightforward interpretation of the study results. The good tolerability and promising efficacy results support further exploration of higher doses of tonabersat in larger controlled trials. © Blackwell Publishing Ltd.

Open Access: Yes

DOI: 10.1111/j.1468-2982.2008.01804.x