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Found 6412 publications

Sharing communities – Community currency in the sharing economy

Eszter Szemerédi Tatay Tibor

Publication Name: Society and Economy

Publication Date: 2021-03-01

Volume: 43

Issue: 1

Page Range: 38-59

Description:

For the further development and more efficient operation of the sharing economy, a fast and inexpensive peer-to-peer payment system is an essential element. The aim of this study is to outline a prototype that ensures the automation and decentralization of processes through smart contracts without blockchain technology. The model has been built based on the narrative that a community currency created through smart contracts can promote genuine practices of sharing as opposed to the profit-oriented approach that most of the currently operating sharing economy platforms have. Features of the model, such as ease of use, high-speed transactions without transaction cost are benefits that can provide a more efficient alternative to the traditional or to the cryptocurrency-based centralized sharing economy platforms.

Open Access: Yes

DOI: 10.1556/204.2020.00027

Conjugacy in the discretized fold bifurcation

Gyula Farkas

Publication Name: Computers and Mathematics with Applications

Publication Date: 2002-01-01

Volume: 43

Issue: 8-9

Page Range: 1027-1033

Description:

In this paper, we construct a conjugacy between the time-1-map of the solution flow generated by an ordinary differential equation and its numerical approximation in a neighborhood of a fold bifurcation point. Our main result is that the conjugacy is O(hp)-close to the identity on the center manifold where h is the step size and p is the order of the numerical method. © 2002 Elsevier Science Ltd. All rights reserved.

Open Access: Yes

DOI: 10.1016/S0898-1221(02)80011-6

Interaction Patterns of Spatial Navigation in VR Workspaces

Adam B. Csapo Anna Sudar

Publication Name: 10th IEEE International Conference on Cognitive Infocommunications Coginfocom 2019 Proceedings

Publication Date: 2019-10-01

Volume: Unknown

Issue: Unknown

Page Range: 615-618

Description:

During the discovery of any new environment-be it real or virtual-the first step is usually that of exploration. The goal exploration in this context is to find the location that provides the most informative, or otherwise useful viewpoint in the space. Depending on the complexity of the space and the task at hand, this can be a difficult challenge. Nevertheless, the finding of useful viewpoints can be facilitated, at least in virtual reality, by changing the layout of the space, as well as by changing other visual features to lower the cognitive load of navigation. In this paper, we present a set of experiments using the MaxWhere desktop virtual environment which suggest that besides the arrangement of a space, its key points of discovery can also influence the time it takes to accomplish a task. This conclusion is supported both by data on key points of navigation and on the activation mode that was utilized on the various smartboards laid out in 3D space. In this research, we hope to show how specific nodes can be found, based on a data-oriented approach, which can lead users to focus on the most important information and obtain the best overview of any virtual space in general.

Open Access: Yes

DOI: 10.1109/CogInfoCom47531.2019.9089998

Young Adults’ Feelings and Knowledge of Climate Anxiety

Ferenc Bakó András Szeberényi

Publication Name: Journal of Sustainability Research

Publication Date: 2025-06-01

Volume: 7

Issue: 2

Page Range: Unknown

Description:

This study investigates the impact of climate anxiety on young adults’ consumer and social behaviour. Data were collected via a questionnaire survey among 696 university students from Széchenyi István University, Budapest Metropolitan University, and Neumann János University. The survey focused on various aspects of climate anxiety, including its frequency, intensity, perceived life impact, emotional responses, and management strategies. The analysis, supported by AI tools, identified two distinct clusters: one with moderate anxiety levels and a strong interest in learning about climate change, and another with higher anxiety levels but less desire for further information. Various statistical models, including Naive Bayes, logistic regression, and random forests, were employed to identify behavioural patterns, with decision trees showing the lowest classification error. The study highlights the significant influence of climate anxiety on the shift towards sustainable consumption and active engagement in climate action. Recommendations for future research include the broader application of deep learning models and extending the study to other demographic groups. Longitudinal data collection is also suggested to track long-term trends and inform effective public policy and communication strategies. The findings emphasise the need for comprehensive approaches to understanding and addressing climate anxiety’s societal impacts.

Open Access: Yes

DOI: 10.20900/jsr20250025

Computational Wear Prediction in Total Knee Replacements as a Function of Replacement Size

Natalia Dilna Gusztáv Fekete Hai Qiao Wang Márton Máté Izolda Popa-Müller Karol Nemoga

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 494-500

Description:

Wear is the third most important factor that restricts the longevity of total knee replacements (TKRs). Wear is particularly influenced by load, local kinematics between the contact surfaces and presumably by the geometry of the contact surfaces. This article investigated, by means of multibody models, how wear in total knee replacements is affected by the size of a TKR or by TKR-related geometric parameters during gait motion. As a result, it has been established that wear rate increases linearly as a function of TKR size, while the impact of TKR-related geometric parameters can be described by linear or quadratic functions. One can conclude that the newly introduced dimensionless parameters can provide guidelines to effectively minimize wear in TKRs.

Open Access: Yes

DOI: 10.3233/ATDE240585

High Precision Test System for the Investigation of the Condition of Lithium-ion Batteries

Adrienn Dineva Krisztian Ferko Miklos Szekely Gyula Gyoker Istvan Vajda

Publication Name: 2018 International Symposium on Fundamentals of Electrical Engineering Isfee 2018

Publication Date: 2018-11-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Modern electric drive systems require more sophisticated monitoring and diagnosis methods for determining the expected life-Time and reliability. Recently, continuous assessment of the electrical condition of electrical machines has become increasingly important. Investigations to predict battery life are of the utmost importance for Electric Vehicles (EVs). The evaluation of the instantaneous State-of-Health (SoH) of the battery cell packs requires a precise measurement system that encompasses the especially important specifications related to the operating conditions. In addition modern Battery Management Systems (BMS) rely on empirical battery models whose parametrization is crucial from the reliability's point of view. The model parameters are necessary to be indentified via the appropriate measurement data. To address these considerations, this paper presents a new test system for Li-ion batteries and control software based on LabView, which is capable of conducting high quality and completely automated battery cell measurements defined by user input test vectors and test suites. The test system allows conducting also real time condition monitoring in Li-ion batteries by discharge impulse responses. Finally several measurements on the experimental setup are performed. Analysis of the measured data validate that the designed device ensures high performance testing and post-processing.

Open Access: Yes

DOI: 10.1109/ISFEE.2018.8742422

Reconstruction of myocardial short-scan SPECT images

Balázs Benyó Ákos Szlávecz Péter Várady Tamás Bükki

Publication Name: Ines 05 IEEE 9th International Conference on Intelligent Engineering Systems Proceedings

Publication Date: 2005-01-01

Volume: 2005

Issue: Unknown

Page Range: 37-41

Description:

In myocardial perfusion SPECT imaging the effect of photon attenuation may introduce artifacts in the reconstructed image due to the highly non-uniform distribution of tissue in the thorax region, potentially resulting in false-positive interpretations. It was the general consideration that the adequate compensation of photon attenuation requires, that the emission data be measured at projection angles over 2π in the case of the attenuation medium is inhomogeneous. The reduction of the scanning angle in SPECT imaging may be desirable because it can reduce scanning time and thereby minimize patient-motion and other artifacts. In SPECT myocardial imaging emission data is measured historically at projection angles over π from the right anterior oblique (RAO) to the left posterior oblique (LPO). This configuration results in better image contrast and, in some cases, betters spatial resolution. However, in this case the reconstructed image may suffer more severely from geometric distortion than 2π angular sampling. It has been proven recently in analytical computer simulation studies that the data function over 2π in SPECT with non-uniform attenuation contains redundant information; therefore the scanning angle theoretically can be reduced from 2π to π without loss of information. In this study our goal was to investigate how the various short-scan SPECT scheme configurations works in a real myocardial SPECT imaging system with highly inhomogeneous attenuating medium using attenuation correction. The measured projection images were reconstructed using the Maximum Likelihood Expectation Maximization algorithm with attenuation correction. The reconstructed slices of the various short-scan configurations and the full-scan slices were compared by a cardiac stress/rest software package. © 2005 IEEE.

Open Access: Yes

DOI: 10.1109/INES.2005.1555127

TP Transformation Based Observer and Controller Design of 2DoF Aeroelastic Wing Section Model

Miklós Kuczmann Andrea Weber

Publication Name: 2022 IEEE 1st International Conference on Internet of Digital Reality Iod 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 17-22

Description:

This paper presents a Tensor Product (TP) model based observer and controller design via Linear Matrix In-equality (LMI) method of 2DoF aeroelastic wing section model. The transformation is based on the Higher Order Singular Value Decomposition HOSVD methodology and the generated linear time-invariant (LTI) vertex systems describe the nonlinear model. The aim of the paper is to investigate that selecting and varying the transformation space and weighting functions have influence on the feasibility regions of LMI based observer and controller. The paper gives a comparison between the controller and observer performance. The proposed method results globally asymptotically stable system, and the LMI gives feasible solution for the observer and controller design if the transformation space and weighting functions are selected adequately.

Open Access: Yes

DOI: 10.1109/IoD55468.2022.9986922

Nonlinear two-dimensional motional finite element modeling of a Rotational eddy current field problem

Miklós Kuczmann Dániel Marcsa

Publication Name: Przeglad Elektrotechniczny

Publication Date: 2009-12-01

Volume: 85

Issue: 12

Page Range: 110-113

Description:

Rotational eddy current field problems with nonlinear effect can be solved by different potential formulations combining motion voltage term. The potential formulations are the motional Az.ast; - A - potential formulation and the motional T,φ - φ - potential formulation taking the nonlinearity of the material into account. The nonlinearity has been handled by the fixed point iteration technique (FPT). The paper presents and compares these formulations through the modified version of TEAM Problem No. 30a, which contains two induction motors.

Open Access: Yes

DOI: DOI not available