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Found 6289 publications

Modeling of railway transition zones under dynamic loading

No authors available

Publication Name: ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering

Publication Date: 2017-01-01

Volume: 2017-September

Issue:

Page Range: 1369-1372

Description:

Transition zones of railway tracks are intended to provide a smooth transition of the riding train, minimizing the effect of the discontinuities that exist along the track. When a train rides from an embankment onto a stiff structure, such as a bridge, tunnel or culvert, an abrupt change in the support stiffness occurs possibly inducing differential settlements. This in long term can yield to the degradation of the tracks and foundations in the transition zones. The differential settlement is especially problematic for high speed rail infrastructure as the "bump" at the transition is accentuated at high speeds. A number of techniques have been proposed or implemented to provide gradual stiffness transition at the problem zones, such as methods to ensure gradually changing pad stiffness, application of long sleepers or installation of auxiliary rails in the transition zone. The problems associated with the transition zones require a complex analysis. For efficient modeling of the mechanisms resulting in gradual line deteriorations in the transition zones the understanding of the 3D and dynamic effects associated with the problem seems to be essential. To enhance our understanding regarding the problem a 3D numerical model has been developed and presented for time domain analysis.

Open Access: No

DOI: DOI not available

Effects of local ground conditions on site response analysis results in Hungary

No authors available

Publication Name: ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering

Publication Date: 2017-01-01

Volume: 2017-September

Issue:

Page Range: 2003-2006

Description:

Ground conditions play an important role for both seismic hazard assessment and structural design for seismic actions. Generally, 1D site response analysis is the first step toward evaluating local conditions. Often the process is simplified by applying a single reference peak ground acceleration general response spectrum based on soil category. Seismic waves are amplified selectively by near-surface soil deposits that possess strain dependent stiffness and damping parameters that vary with each layer as well as with depth. In order to take these local ground conditions into account, field investigations were carried out for this study. Seismic CPT and MASW measurements were used for determining in situ small strain stiffness profiles at different locations in Hungary. Results of the investigations were used as input data for ground response analyses. Results are presented to show benefits of the detailed investigations as compared to simplified analysis methods based on estimated soil parameters and to EC-8 design spectra.

Open Access: No

DOI: DOI not available

Position sensitivity study in molecular dynamics simulations of self-organized development of 3D nanostructures

Ibolya Zsoldos Istvan Laszlo David Fulep

Publication Name: Materials Science Forum

Publication Date: 2017-01-01

Volume: 885

Issue: Unknown

Page Range: 216-221

Description:

The sensitivity of defect free fusion of straight carbon nanotubes from graphene nanoribbons to the position of the nanoribbon edge positions has been investigated. A basic difference between the behavior of armchair and zigzag type nanoribbons was observed. When placing armchair type graphene nanoribbons above each other identical, fitting positions are obtained automatically. Zigzag type graphene nanoribbons, however, must not be placed above each other in identical positions. From the viewpoint of defect-free fusion, according to the MD simulations symmetric on nearly symmetric positions of the ribbon edges are favorable.

Open Access: Yes

DOI: 10.4028/www.scientific.net/MSF.885.216

Evaluation of training to improve auditory memory Capabilities on a mobile device based on a serious game application

Hunor Nagy György Wersényi

Publication Name: 142nd Audio Engineering Society International Convention 2017 AES 2017

Publication Date: 2017-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Capabilities of the auditory memory system were tested in a serious game application developed for the Android mobile platform. Participants played the well-known game of finding pairs by flipping and remembering objects on cards arranged in a matrix structure. Visual objects were replaced by iconic auditory events (auditory icons, earcons). Total time and different error rates were recorded and the effect of training was also evaluated. Results indicate that training contributes to a better performance and human voice samples are the easiest to remember.

Open Access: Yes

DOI: DOI not available

The coupled cluster method and entanglement in three fermion systems

Gábor Sárosi János Pipek Péter Lévay Szilvia Nagy

Publication Name: Journal of Mathematical Physics

Publication Date: 2017-01-01

Volume: 58

Issue: 1

Page Range: Unknown

Description:

The Coupled Cluster (CC) and full CI expansions are studied for three fermions with six and seven modes. Surprisingly the CC expansion is tailor made to characterize the usual stochastic local operations and classical communication (SLOCC) entanglement classes. It means that the notion of a SLOCC transformation shows up quite naturally as a one relating the CC and CI expansions, and going from the CI expansion to the CC one is equivalent to obtaining a form for the state where the structure of the entanglement classes is transparent. In this picture, entanglement is characterized by the parameters of the cluster operators describing transitions from occupied states to singles, doubles, and triples of non-occupied ones. Using the CC parametrization of states in the seven-mode case, we give a simple formula for the unique SLOCC invariant I. Then we consider a perturbation problem featuring a state from the unique SLOCC class characterized by I. For this state with entanglement generated by doubles, we investigate the phenomenon of changing the entanglement type due to the perturbing effect of triples. We show that there are states with real amplitudes such that their entanglement encoded into configurations of clusters of doubles is protected from errors generated by triples. Finally we put forward a proposal to use the parameters of the cluster operator describing transitions to doubles for entanglement characterization. Compared to the usual SLOCC classes, this provides a coarse grained approach to fermionic entanglement.

Open Access: Yes

DOI: 10.1063/1.4974510

Overall imperfection method for beam-columns

G. Hajdú Ferenc Papp

Publication Name: Advances and Trends in Engineering Sciences and Technologies II Proceedings of the 2nd International Conference on Engineering Sciences and Technologies Esat 2016

Publication Date: 2017-01-01

Volume: Unknown

Issue: Unknown

Page Range: 87-92

Description:

The principles and applications of the overall imperfection method for beamcolumns are presented in this paper. The buckling resistance of a beam-column member is determined by the resistance of its critical cross-section taking into account the second-order effect. The maximum amplitude of the initial imperfection, in the shape of elastic buckling mode, is determined from fundamental cases. Fundamental case: simply-supported member with uniform cross-section subjected to uniformly distributed forces. The standardized buck-ling resistance of this reference member is based on theoretical and empirical background. The proposed overall imperfection method is adequate for computer-aided design procedures which contains an advanced elastic beam-column finite element method. The accuracy of the overall imperfection method is shown by a parametric study.

Open Access: Yes

DOI: DOI not available

Direct local economic impact of Budapest Liszt Ferenc International Airport

Dusek Tamás Lukovics Miklós Krisztián Koppány Bohl Patrick Poreisz Veronika

Publication Name: Teruleti Statisztika

Publication Date: 2017-01-01

Volume: 57

Issue: 1

Page Range: 76-93

Description:

Airports play a dominant role in today's longdistance transport and they also represent significant nodes of the modern globalised economy. By estimating direct and indirect impacts on employment and income, their importance can be characterized in quantifiable terms. This study aims to estimate the direct economic impacts of Budapest Liszt Ferenc Airport as a complex economic entity involving a number of companies that are legally separate but complementary to one another and operate in the Airport's area - after outlining the general issues related to the impact assessment of airports. The study addressed two years, 2009 and 2014, which made it possible to compare the circumstances before and after the termination of Malév.

Open Access: Yes

DOI: 10.15196/TS570104

Comparison of HRTFs from a dummy-head equipped with hair, cap and glasses in a virtual audio listening task over equalized headphones

József Répás György Wersényi

Publication Name: 142nd Audio Engineering Society International Convention 2017 AES 2017

Publication Date: 2017-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Head-Related Transfer Functions (HRTFs) are frequently used in virtual audio scene rendering in order to simulate sound sources at different spatial locations. The use of dummy-head HRTFs (also referred as generic sets) is often criticized because of poor localization performance, leading to e.g. lower spatial resolution, in-thehead localization, front-back reversals etc. This paper presents results of horizontal plane localization obtained by digital filter representations of dummy-head HRTFs that were recorded normally, and using additional cap, glasses and hair on the head. Results of untrained subjects over equalized reference headphones showed no significant difference among the HRTF sets despite of large magnitude differences. This method for customization of generic HRTFs fails if improvement in localization is needed.

Open Access: Yes

DOI: DOI not available

Fast and direct screening of copper in micro-volumes of distilled alcoholic beverages by high-resolution continuum source graphite furnace atomic absorption spectrometry

Gabriella Dravecz Nikoletta Laczai Áron Marosi Bence Marlok Norbert Szoboszlai Zsolt Ajtony László Bencs Christina Streli

Publication Name: Food Chemistry

Publication Date: 2016-12-15

Volume: 213

Issue: Unknown

Page Range: 799-805

Description:

HR-CS-GFAAS methods were developed for the fast determination of Cu in domestic and commercially available Hungarian distilled alcoholic beverages (called pálinka), in order to decide if their Cu content exceeds the permissible limit, as legislated by the WHO. Some microliters of samples were directly dispensed into the atomizer. Graphite furnace heating programs, effects/amounts of the Pd modifier, alternative wavelengths (e.g., Cu I 249.2146 nm), external calibration and internal standardization methods were studied. Applying a fast graphite furnace heating program without any chemical modifier, the Cu content of a sample could be quantitated within 1.5 min. The detection limit of the method is 0.03 mg/L. Calibration curves are linear up to 10–15 mg/L Cu. Spike-recoveries ranged from 89% to 119% with an average of 100.9 ± 8.5%. Internal calibration could be applied with the assistance of Cr, Fe, and/or Rh standards. The accuracy of the GFAAS results was verified by TXRF analyses.

Open Access: Yes

DOI: 10.1016/j.foodchem.2016.06.090