Search Everything

Tip: Search using "First Name + Last Name", e.g.
János Kiss instead of Kiss János.

Publications - 6374

ALTERNATIVE USES FOR CRUSHED STONE PRODUCTS GENERATED TO MEET THE RAW MATERIAL NEEDS OF ASPHALT PRODUCTION IN HUNGARY

Szabolcs Fischer Laszlo Ezsias

Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu

Publication Date: 2023-11-30

Volume: Unknown

Issue: 5

Page Range: 66-71

Description:

In Hungary, quarries that produce stone products for wearing courses of asphalt pavements also produce a significant amount of 0/4, 0/8 and 4/8 mm fractions. Because of Hungary’s pavement design and asphalt production practices, these fractions do not have a suitable market and can thus be sold on alternative markets. Purpose. To demonstrate the feasibility of using crushed fractions of 0/4 and 0/8 mm in the protection and base layers of asphalt pavements instead of sandy gravel with 0/22 mm fraction. Methodology. The CBR method was applied to evaluate the comparability of characteristics such as particle size distribution and loadbearing capacity. The combination of the Proctor and CBR tests allowed someone to compare the expected technological characteristics of the dominant and alternative aggregate types, such as their sensitivity to water and loadbearing capacity. Findings. The results demonstrated that the performance characteristics of conventionally used sandy gravel with a size of 0/22 mm can be achieved and exceeded by crushed material with much smaller maximum grain sizes – i.e., 0/4 and 0/8 mm. Originality. The paper presents an original study that contradicts the industry’s actual decline of crushed stone (0/4 and 0/8 mm fractions) for asphalt pavement protection layers. The potential effectiveness and functionality of the proposed coating are demonstrated through convincing tests, and thus new data and insights are introduced into the Hungarian construction industry’s practice. Practical value. The test results greatly helped in achieving the high demands of the private industrial project by proposing an alternative variant of crushed stone of 0/8 mm fraction rather than the originally planned dominant sand and gravel material. The asphalt paving experience on this site clearly demonstrated the viability of the alternative aggregate option for Hungarian roads.

Open Access: Yes

DOI: 10.33271/NVNGU/2023-5/066

Elasto-Plastic limit analysis of reliability based geometrically nonlinear bi-directional evolutionary topology optimization

János Lógó Majid Movahedi Rad Muayad Habashneh

Publication Name: Structures

Publication Date: 2021-12-01

Volume: 34

Issue: Unknown

Page Range: 1720-1733

Description:

This paper presents elasto-plastic limit analysis of reliability-based geometrically nonlinear topology optimization. For this purpose, by reason of uncertainties the volume fraction is considered randomly during optimization. Thus reliability-based design has been considered for solving the problems. To perform reliability-based topology optimization design, the Monte-Carlo simulation method has been applied to calculate the probability of failure, thus the reliability index. Besides, bi-directional evolutionary structural optimization (BESO) method is used to consider the effect of geometrically nonlinear design for elasto-plastic analysis. Plastic behavior is controlled by applying a bound on the plastic limit load multipliers using limit analysis. The adequacy of the proposed method is exhibited by three 2D benchmark problems. 2D models of L-shape beam and U-shaped plate are considered for reliability-based design and geometrically nonlinear analysis topology optimization in case of elastic material. Additionally, 2D and 3D elasto-plastic material models have been considered to demonstrate that the proposed method can find the optimal topology of elasto-plastic models for reliability-based design and geometrically nonlinear analysis.

Open Access: Yes

DOI: 10.1016/j.istruc.2021.08.105

Transformer model identification by artap: A benchmark problem

Miklós Kuczmann Gergely Kovács Attila Szöcs

Publication Name: Periodica Polytechnica Electrical Engineering and Computer Science

Publication Date: 2021-04-27

Volume: 65

Issue: 2

Page Range: 123-130

Description:

The paper presents how Artap can be used for determining the equivalent circuit parameters of a one phase transformer as a benchmark problem. The following unknown parameters of the equivalent circuit are identified: primary resistance and primary leakage reactance, secondary resistance and secondary leakage reactance, finally magnetizing resistance, and magnetizing reactance. The known quantities from measurement are the primary voltage, primary current, power factor, secondary voltage, and the load resistance. Algorithms implemented in Artap are used for determining the transformer parameters and the results are compared with the analytical solution.

Open Access: Yes

DOI: 10.3311/PPee.17606

Parametric Analysis of Metal Matrix Syntactic Foams

Imre Fekete Imre Czinege

Publication Name: Lecture Notes in Mechanical Engineering

Publication Date: 2026-01-01

Volume: Unknown

Issue: Unknown

Page Range: 15-33

Description:

Metal matrix syntactic foams are playing an increasingly important role in different structures. Their application is primarily aimed at weight reduction and energy absorption. The present research uses sensitivity analysis, response surface methodology, and principal component analysis to quantify the effect of matrix yield strength, matrix-to-filler ratio, ceramic sphere wall strength, and wall thickness-to-diameter ratio on the critical compressive strength of metal matrix syntactic foam. It was found that the thickness-to-diameter ratio and strength of the sphere wall are the determining factors in the evolution of the compressive strength, but the matrix strength has less effect on the output.

Open Access: Yes

DOI: 10.1007/978-981-96-6452-8_2

Maximal entropy and minimal variability OWA operator weights: A short survey of recent developments

Christer Carlsson Robert Fuller

Publication Name: Studies in Fuzziness and Soft Computing

Publication Date: 2018-01-01

Volume: 357

Issue: Unknown

Page Range: 187-199

Description:

The determination of ordered weighted averaging (OWA) operator weights is a very important issue of applying the OWA operator for decision making. One of the first approaches, suggested by O’Hagan, determines a special class of OWA operators having maximal entropy of the OWA weights for a given level of orness; algorithmically it is based on the solution of a constrained optimization problem. In 2001, using the method of Lagrange multipliers, Fullér and Majlender solved this constrained optimization problem analytically and determined the optimal weighting vector. In 2003 Fullér and Majlender computed the exact minimal variability weighting vector for any level of orness using the Karush-Kuhn-Tucker second-order sufficiency conditions for optimality. The problem of maximizing an OWA aggregation of a group of variables that are interrelated and constrained by a collection of linear inequalities was first considered by Yager in 1996, where he showed how this problem can be modeled as a mixed integer linear programming problem. In 2003 Carlsson, Fullér and Majlender derived an algorithm for solving the constrained OWA aggregation problem under a simple linear constraint: the sum of the variables is less than or equal to one. In this paper we give a short survey of numerous later works which extend and develop these models.

Open Access: Yes

DOI: 10.1007/978-3-319-60207-3_12

Vulnerability assessment of residential buildings in Jeddah: A methodological proposal

O. Kegyes-Brassai Ahmed Al-ghamadi Md Faiz Shah Anas Ahmed Anas Ahmed R. P. Ray

Publication Name: International Journal of Geomate

Publication Date: 2018-01-01

Volume: 14

Issue: 44

Page Range: 134-141

Description:

The City of Jeddah in Saudi Arabia is expanding rapidly, in terms of new buildings and increasing population. The rapid urbanization leads to higher risk from seismic events; even in areas of moderate seismicity such as this city. The present study addresses the rapid evaluation of a large number of buildings in Jeddah involving steps to determine hazard, assessing building stock, and computing vulnerability with a scoring method from FEMA 155. Two districts were selected for investigation based on a cluster analysis applied to population and building data from the local municipality. One selected district was a contemporary developed urbanized area, and the other was a more traditional area. Such selection offered the possibility to compare vulnerability of buildings built according to different seismic codes and to make assumptions about the rest of the city based on typical structures of districts. The basic structural score was determined considering the building structure and moderate seismicity of the region using score modifiers, e.g. vertical irregularity score modifier; soil score modifier assuming sabkahs. The results of the investigation reveal a different level of vulnerability and areas where intervention is needed. The method can be applied for further analysis of the city.

Open Access: Yes

DOI: 10.21660/2018.44.85087

LPV type model of deformational force in vehicle collisions

István A. Harmati András Rövid Peter Varlaki

Publication Name: Iccc 2009 IEEE 7th International Conference on Computational Cybernetics

Publication Date: 2009-12-01

Volume: Unknown

Issue: Unknown

Page Range: 103-108

Description:

Modeling of the deformational force and absorbed energy plays a very important role in different fields of vehicle engineering. The usually applied FEM based methods give good approximations, but they have extremely large computational complexity. On the other hand there exist simple force models, but they not approximate well in details the real data. The aim of this paper is to introduce a force model for vehicle deformation, which is able to describe the real process and have acceptable complexity. ©2009IEEE.

Open Access: Yes

DOI: 10.1109/ICCCYB.2009.5393952

Optimizing asphalt foaming using neural network

A. Saleh László Gáspár

Publication Name: Pollack Periodica

Publication Date: 2024-03-22

Volume: 19

Issue: 1

Page Range: 130-136

Description:

This study uses a three-layer backpropagation neural network combined with particle swarm optimization to control the foamed bitumen in cold recycling technology. The foaming process of bitumen is non-linear and depends on dynamic temperature. By developing a neural network model, this study effectively captures the complex relationships between temperature, water content, air pressure, and the expansion ratio and half-life of foamed bitumen. The integration of particle swarm optimization enhances the accuracy and convergence of the neural network model by optimizing the initial weights. This optimization process improves the model's ability to predict and control the quality of foamed bitumen accurately. It serves as a valuable tool for the rapid development of high-quality cold asphalt design.

Open Access: Yes

DOI: 10.1556/606.2023.00896

On the non hierarchical matrix representation of the negative, non integer order sobolev norms

Béla Kiss

Publication Name: Lecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics

Publication Date: 2006-06-29

Volume: 3743 LNCS

Issue: Unknown

Page Range: 663-670

Description:

In this paper a new cyclic matrix representation of the Sobolev norms Ha, a ∈ (-1, 0) are presented. The matrix-vector multiplication by these matrices requires only O(N · log(N)) arithmetic operations, where N is the number of unknowns, The application of the new H-1/2 norm representation as Schur complement preconditioning matrix requires only matrix-vector multiplication. The efficiency of the construction to elliptic problems has been verified by numerical tests. © Springer-Verlag Berlin Heidelberg 2006.

Open Access: Yes

DOI: 10.1007/11666806_76