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Found 6374 publications

Benchmarking methodology for IPv4aaS technologies: Comparison of the scalability of the Jool implementation of 464XLAT and MAP-T

Ádám Bazsó Gábor Lencse

Publication Name: Computer Communications

Publication Date: 2024-04-01

Volume: 219

Issue: Unknown

Page Range: 243-258

Description:

A novel method is proposed for the performance and scalability measurements of the IPv4-as-a-Service (IPv4aaS) technologies. It works according to the dual Device Under Test (DUT) setup of RFC 8219 and is suitable for benchmarking any of the five IPv4aaS technologies: Combination of Stateful and Stateless Translation (464XLAT), Dual-Stack Lite (DS-Lite), Lightweight 4over6 (Lw4o6), Mapping of Address and Port with Encapsulation (MAP-E), and Mapping of Address and Port using Translation (MAP-T). The method is based on the reduction of the aggregate of Customer Edge (CE) and Provider Edge (PE) devices to a stateful network address translation from IPv4 to IPv4 (stateful NAT44) gateway. The most important advantage of the novel method is that a stateful NAT44 tester can be used instead of a technology-specific tester, which usually does not exist. The proposed method is validated by the examination of the performance and scalability of the Jool implementation of 464XLAT and MAP-T. Scalability is defined by both (1) how performance increases with the number of active Central Processing Unit (CPU) cores; and (2) how performance decreases with the increasing number of concurrent sessions. Maximum connection establishment rate and throughput are used as performance metrics. The scalability of 464XLAT and MAP-T is measured from 1 to 16 CPU cores and from 1 million to 256 million connections. The measurement details and results are fully disclosed and discussed.

Open Access: Yes

DOI: 10.1016/j.comcom.2024.03.007

Searching possible accident black spot locations with accident analysis and gis software based on GPS coordinates

Csaba Koren Attila Borsos Pál Hegyi

Publication Name: Pollack Periodica

Publication Date: 2017-12-01

Volume: 12

Issue: 3

Page Range: 129-140

Description:

There are several methods for the analysis of road accidents in a road network. In Hungary from 2011 GPS coordinates are used to identify the location of personal injury accidents. This method significantly improves the display of locations of accidents on the map, which can be then analyzed using GIS tools. Accident black spots are the most dangerous places in road networks identified by the density of the accidents in the network. One of the analysis methods is the accident density searching. The methods and algorithms used in some software may show differences in relation to one another. The aim of this research is comparing two applications by investigating the local road network in Györ. The analysis was made using the WEB-BAL accident analysis software using the density-based spatial clustering of applications with noise procedure and the QGIS software using the kernel density estimation method. The former is the official accident database and online software used for accident investigations and the latter is an open source geographic information system. The results are visualized in accident density plots and black spot maps.

Open Access: Yes

DOI: 10.1556/606.2017.12.3.12

Visualization and art in the mathematics classroom

No authors available

Publication Name: ZDM - International Journal on Mathematics Education

Publication Date: 2003-12-01

Volume: 35

Issue: 1

Page Range: 24-29

Description:

In this paper we summarize our concepts and practice on computer-aided mathematical experimentation, and illustrate them by Mathematica projects that we have developed for our research and the courses "Computer-aided mathematical modelling" and "Computer Algebra I-II" held for students of life sciences at University of Szeged and computational engineering at TFH Berlin, University of Applied Sciences.

Open Access: No

DOI: DOI not available

Tempering effects in steel parts produced by additive fabrication using laser powder deposition

No authors available

Publication Name: Virtual Modelling and Rapid Manufacturing - Advanced Research in Virtual and Rapid Prototyping

Publication Date: 2003-12-01

Volume:

Issue:

Page Range: Unknown

Description:

Laser processed tool steels present a metastable structure generally containing martensite and an extremely large proportion of retained austenite as compared to conventionally treated steel, which affects considerably the properties of the material. In rapid tooling by laser powder deposition, as consecutive layers of material are deposited to generate a 3D object, the material in previously deposited layers is submitted to successive thermal cycles, which destabilise retained austenite, leading to its transformation to martensite. Also, the martensite present in these layers will progressively decompose by tempering when the material is reheated. As a result, the properties of the material are progressively modified as the object is built-up. The evolution of the microstructure and properties of tool steels during laser freeform manufacturing is extremely difficult to study experimentally, due to the complexity of the transformations involved and the heterogeneity of the material and of the applied thermal field, hence modelling presents clear advantages in the optimization of part build-up strategy. In the present work, a model of the phase transformations resulting from the successive overlap of clad layers based on the coupling of finite element calculations of the time-dependent temperature distribution with transformation kinetics is described. The model was used to predict the evolution of properties and final property distribution in a martensitic stainless steel component produced by laser powder deposition.

Open Access: No

DOI: DOI not available

Trends of using social media for the green labelling of modern mobile phones

Petra Kecskés Veronika Keller Sewar Alkhatib

Publication Name: Cogent Business and Management

Publication Date: 2024-01-01

Volume: 11

Issue: 1

Page Range: Unknown

Description:

This study explores contemporary practices by three major companies, Samsung, Apple and Huawei, to promote the environmentally friendly attributes of mobile phones by utilizing social media platforms. The research employs a combination of literature review and data analysis to investigate the strategies used by these companies in advertising their environmental initiatives on popular social media platforms such as Facebook, Instagram, YouTube and Twitter. The findings underscore the increasing significance of social media in the realm of green labelling initiatives. The study reveals the potential of social media to enhance customer awareness and influence purchasing behaviour in the dynamic mobile phone sector. The article recommends further research in this domain to guide manufacturers in formulating effective strategies amid the evolving landscape of the mobile phone industry.

Open Access: Yes

DOI: 10.1080/23311975.2024.2373357

Biomedical Engineering Education and Related Research Activity in Hungary

No authors available

Publication Name: Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings

Publication Date: 2003-12-01

Volume: 4

Issue:

Page Range: 3533-3535

Description:

Biomedical Engineering is a relatively new interdisciplinary science. This paper presents the biomedical engineering activity, which is carried out at Budapest University of Technology and Economics and its partner institutes. In the first part the main goals and the curriculum of the Biomedical Engineering ducation Program (BMEEP) is presented. The second part of the paper summarizes the most important biomedical engineering researches carried out mostly in the Biomedical Engineering Laboratory of our university.

Open Access: No

DOI: DOI not available

A simple technique to estimate the processing window for laser clad coatings

No authors available

Publication Name: International Surface Engineering Congress - Proceedings of the 1st Congress

Publication Date: 2003-12-01

Volume:

Issue:

Page Range: 237-242

Description:

A semi-empirical method for selecting the processing parameters of laser cladding is proposed. This phenomenological approach uses simple mathematical formulae, derived from a statistical analysis of measured data, to relate the laser cladding parameters with the geometric features of the clad track. Given the required clad height and available laser beam power, the proposed method allows one to calculate values of the scanning speed and powder feed rate which are used to obtain low dilution, pore free coatings, fusion bonded to the substrate. To illustrate the application of this method, variable powder feed rate laser cladding experiments were carried out with Stellite 6 powder on mild steel substrates. In this technique the laser beam power and radius and the processing speed are kept constant, while the powder feed rate is varied along a single track length according to a specified linear function. The expressions derived from the model were used to plot the experimental data in a coherent manner, revealing the combined role of the different processing parameters.

Open Access: No

DOI: DOI not available

Innovative Design Techniques for Sinusoidal-Web Beams: A Reliability-Based Optimization Approach

János Szép Majid Movahedi Rad Muayad Habashneh Imre Cserpes

Publication Name: Buildings

Publication Date: 2024-04-01

Volume: 14

Issue: 4

Page Range: Unknown

Description:

Existing studies often rely on deterministic numerical analyses for structural models. However, test results consistently highlight uncertainties, particularly in variables such as magnitude of the applied load, geometrical dimensions, material randomness, and limited experiential data. As a response, researchers have increasingly turned their attention to probabilistic design models, recognizing their crucial role in accurately predicting structural performance. This study aims to integrate reliability-based analysis into the numerical modeling of sinusoidal-web steel beams. Two sinusoidal-web beams are considered. The web and the flange thicknesses, in addition to the magnitude of the applied load, are treated as random variables with mean values and standard deviations. Notably, the study demonstrates the efficiency of the reliability index as a governing limit in the analysis process. A detailed comparison between deterministic and probabilistic designs of sinusoidal-web beams is conducted, focusing on the impact of introducing the nature of randomness. Therefore, this study’s results deepen our understanding of how uncertainties significantly influence deformations and stresses.

Open Access: Yes

DOI: 10.3390/buildings14041051

Dimensioning of the reinforced concrete structures old and new presrciptions in Hungary

No authors available

Publication Name: Proceedings of the fib Symposium 2003: Concrete Structures in Seismic Regions

Publication Date: 2003-01-01

Volume:

Issue:

Page Range: 264-265

Description:

Open Access: No

DOI: DOI not available