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Found 6423 publications

Direct preisach hysteresis model for finite element analysis of magnetic fields

Miklós Kuczmann Dániel Marcsa

Publication Name: Przeglad Elektrotechniczny

Publication Date: 2009-12-01

Volume: 85

Issue: 12

Page Range: 114-117

Description:

This paper deals with the numerical analysis of the Problem No. 32 of the TEAM Workshops. This is a three-limbed ferromagnetic core with pick up coils, which is a test bench for validation of numerical analysis with hysteresis. The numerical procedure is based on the magnetic field computation taking the hysteresis into account. The scalar Preisach model is integrated into a finite element analysis. The hysteretic nonlinearity is handled by the fixed point iterative technique. The results are validated by comparison with the experiments.

Open Access: Yes

DOI: DOI not available

Graphene-based molecular dynamics nanolithography of fullerenes, nanotubes and other carbon structures

Ibolya Zsoldos István László

Publication Name: Epl

Publication Date: 2012-09-01

Volume: 99

Issue: 6

Page Range: Unknown

Description:

The mass production of fullerenes and nanotubes faces the problem of their selective production. Here we present special kind of graphene patterns which can be used as initial structures for fullerenes, nanotubes and other carbon nanostructures. We proved in quantum chemical molecular dynamics calculations that these structures transform in a self-organizing way into the desired structures. Our results can initiate new experimental researches for improving the existing carbon nanostructure productions and to develop a new, structure-selective nanolithography of fullerenes, nanotubes and other carbon structures. We present such kind of graphene patterns which generate the self-organizing processes. In our molecular dynamics simulation we obtained the C 60 and C 70 fullerene, the (5,5) armchair nanotube and (9,0) zigzag nanotube. We present also a graphene pattern for self-organizing Y junction production. © Copyright EPLA, 2012.

Open Access: Yes

DOI: 10.1209/0295-5075/99/63001

Development of Safety Performance Functions for Two-Lane Rural First-Class Main Roads in Hungary

Attila Borsos Gyula Orosz John N. Ivan

Publication Name: Traffic Safety Volume 4

Publication Date: 2016-01-01

Volume: 4

Issue: Unknown

Page Range: 87-100

Description:

This chapter describes a modeling effort to define accident prediction models for first-class main roads outside built-up areas in Hungary using variables that are available and believed to exert an influence on safety performance. Models are proposed using the Generalized Linear Modeling (GLM) approach assuming a negative binomial error structure. The chapter also overviews design characteristics and accident statistics of two-lane rural first-class main roads. Five variables are used to predict accident frequencies, Annual Average Daily Traffic (AADT), posted speed, curve, roadway width and shoulder width. Traffic volume is used as an exposure to accidents and the length of the homogenous sections. Safety Performance Functions (SPFs) have been widely used in the traffic safety field for analyzing how the safety performance of road facilities is related to various road characteristics. The chapter reviews literature to demonstrate problems associated with conventional regression techniques used for accident prediction.

Open Access: Yes

DOI: 10.1002/9781119307853.ch6

Comparison of the English and German Concepts of Contract

Judit Beck

Publication Name: Journal on European History of Law

Publication Date: 2025-01-01

Volume: 16

Issue: 2

Page Range: 87-93

Description:

This paper focuses on the English and German concepts of contract. Among other things, our aim is to examine the relationship between the concept of contract and imperial imperialism. In the course of the study, we examine the development and evolution of contract concepts, as well as some similarities and differences between English and German contract law. Among our aims is to show that there is a link between the development of the field of contract law and imperialism. In the course of the study, we will primarily apply the historical and comparative legal methodologies.

Open Access: Yes

DOI: DOI not available

Parallel implementation of a combustion chamber simulation with MPI-OpenMP hybrid techniques

László Környei

Publication Name: Mipro 2012 35th International Convention on Information and Communication Technology Electronics and Microelectronics Proceedings

Publication Date: 2012-08-22

Volume: Unknown

Issue: Unknown

Page Range: 356-361

Description:

The parallelization techniques utilized in a study of gas flow in a combustion chamber are described and discussed in this paper. Models of compressible fluid dynamics are solved with the finite volume method, and an additional algorithm, called "snapper" that handles piston and valve movement. In order to achieve an acceptable scaling on a CPU cluster with 240 cores, a two-stage parallelization with MPI in conjecture with OpenMP is implemented. For some types of physical investigations, the actual spatial region of interest is somehow changing, deforming, or moving in time in a predefined fashion. Handling gas dynamics with piston motion, even with the simplest models requires precaution. Apart from numerical and physical corrections, there are challenges, where multiple types of unstructured, and specially generated deforming grids are handled in a computer system with distributed memory. In the present work the results of the first implementations and benchmarks are presented, which prove to be well scaling for this modest-sized cluster. © 2012 MIPRO.

Open Access: Yes

DOI: DOI not available

Resource savings, recycling and utilization, and energy transition: Introduction

Aviral Tiwari Xin Zhao Umer Shahzad

Publication Name: Geoscience Frontiers

Publication Date: 2024-05-01

Volume: 15

Issue: 3

Page Range: Unknown

Description:

No description provided

Open Access: Yes

DOI: 10.1016/j.gsf.2024.101797

Vibration levels of stacked parcel packages in laboratory test environment. Over-tested or under-tested?

Péter Böröcz Bence Molnar Csaba Pánczél Zsófia Németh

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-08-25

Volume: 14

Issue: 3

Page Range: 259-269

Description:

Courier express parcel (CEP) shipments become one of the most important delivery methods in the Business-to-Consumer sales model. This paper observed and analyzed the vertical vibration levels that occur in stacked and unsecured parcels during express delivery versus the simulation in the laboratory. At the end, a detailed comparison is reported between the field and laboratory vibration levels (based on standard PSD test profile) in the frequency range of 1 – 200 Hz. For the measurement a three-layer stacked unit was used building from corrugated box samples. The result shows and analyzes the vibration levels in the stacked layers in comparison to the ISTA (International Safe Transport Association) vibration protocol where only a single parcel is required to be tested without any stacking configuration.

Open Access: Yes

DOI: 10.14513/actatechjaur.00603

The coronavirus’s effect on the decisions and habits of food purchases in Hungary

Péter Karácsony Tímea Juhász Péter Huszka

Publication Name: Journal of International Studies

Publication Date: 2022-01-01

Volume: 15

Issue: 1

Page Range: 149-167

Description:

This article was inspired by current events. The shopping craze generated by the coronavirus pandemic raised some questions that this article aims to answer by analysing a variety of suppositions. The coronavirus pandemic caused panic shopping amongst consumers, whose motivation for increasing the volumes of shopping revolved around ensuring a safety margin of groceries while also reducing the number of shopping trips. The consumers did most of their shopping in hyper, and supermarkets, as well as in bigger ABCs and grocery stores (Lidl), where there’s a wider range of products and larger stock. The average consumer bought much more than the basic groceries during this period. Our research started in March 2020 and ended in May 2020. To validate our assumptions, primary information is derived from the statistical processing of a large number of data from a representative questionnaire survey of 724 respondents. The results show that for many people this period was about stockpiling storages of groceries. Flour saw the biggest increase in purchase volumes, but chicken and pastas were also amongst the more popular items. Stores with the biggest range of selection were able to satisfy this demand. As evidenced by data, consumers also purchased items, which are needed for any household during an emergency and are easy to store in higher volumes. These items include different oils and fats, which are required for cooking, and non-perishables, such as salamis, canned foods, rice and mineral water.

Open Access: Yes

DOI: 10.14254/2071-8330.2022/15-1/10

Automated elasto-plastic design of truss structures based on residual plastic deformations using a geometrical nonlinear optimization framework

Majid Movahedi Rad Péter Grubits

Publication Name: Computers and Structures

Publication Date: 2025-09-01

Volume: 316

Issue: Unknown

Page Range: Unknown

Description:

This paper introduces a novel automated framework for the optimal design of steel truss structures, incorporating plastic deformations through the complementary strain energy of residual forces while minimizing weight. The presented methodology is equally applicable to purely elastic scenarios, ensuring zero plastic deformations and further reducing material usage. To achieve this, a nonlinear finite element (FE) program was developed, capable of accounting for large deformations and initial geometric imperfections. A genetic algorithm (GA) was integrated to iteratively optimize the objective function, enabling a fully automated design process. The efficiency and versatility of the framework were validated through four numerical examples. The first two comprise benchmark cases: a 9-bar planar truss and a 25-bar space truss. The remaining two examples were selected to be more representative of practical applications, involving a prestressed arched truss and a double-layer space truss. Analyses of various configurations were performed to demonstrate the robustness of the approach. Using the proposed methodology, significant improvements in plastic performance and material efficiency were achieved, underscoring its potential, adaptability, and effectiveness in advancing truss design techniques.

Open Access: Yes

DOI: 10.1016/j.compstruc.2025.107855