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Publications - 6374

A multi-purpose virtual laboratory with interactive knowledge integration

Miklós Kuczmann Tamás Budai

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

Publication Date: 2019-10-01

Volume: Unknown

Issue: Unknown

Page Range: 529-532

Description:

This paper presents the concept of multi-purpose virtual laboratories, a new way to design and utilize 3D virtual learning environments in higher education. The paper introduces the current state of the adoption of new virtual learning environments and proposes a new design methodology in order to improve the quality, user experience and didactic potential of virtual laboratories. To demonstrate the introduced concepts, a practical example is also presented.

Open Access: Yes

DOI: 10.1109/CogInfoCom47531.2019.9089896

Optimal parameter extraction of fuel cells based on interval branch-and-bound optimization algorithm

Raphael Chenouard Ragab A. El-Sehiemy

Publication Name: Energy Reports

Publication Date: 2026-06-01

Volume: 15

Issue: Unknown

Page Range: Unknown

Description:

Fuel cells play an important role in reducing environmental impacts to produce cleaner electricity. Numerical models are used to simulate their performance and build efficient observers in real use. The accuracy of these models is a major concern, as they can be parameterized by several values. Most of the previous works study the estimation of these parameters using various metaheuristics. While these methods are stochastic and do not provide any proof of optimality, the current paper introduces a global optimization method to accurately bound the optimal root mean square error between the parameterized model and some experimental data. The proposed algorithm is based on a deterministic Interval Branch-and-Bound optimization (IBBO) framework. Interval arithmetic ensures set-based computations to safely bound the objective function value. Four types of fuel cells, with their experimental data, are used to demonstrate the efficiency of the proposed methods. IBBO results are compared with some competing optimization methods used in the literature. They show a better accuracy for the computed feasible solutions (upper bounds) and a guaranteed value of the best possible solutions (lower bounds). This last information is not possible to obtain with metaheuristic algorithms. Compared to other Branch-and-Bound algorithms, IBBO proposes a new mix of mechanisms (e.g. advanced constraint propagation, specific search heuristic and feasible point finding method). Due to the deterministic nature of IBBO, results can be repeated. Its convergence analysis is detailed on four fuel cells from which a real test system based on Scribner technology is used to demonstrate the accuracy and robustness of IBBO on several usage scenarios.

Open Access: Yes

DOI: 10.1016/j.egyr.2025.108932

Ecological Impacts of Cultivated Land Conversion and Urban Eco-Resilience in the COP29 Era

Mohd Ziaur Rehman Marek Dudek Xin Zhao Fangxia Pan U. Shahzad

Publication Name: Land Degradation and Development

Publication Date: 2025-12-01

Volume: 36

Issue: 18

Page Range: 6237-6254

Description:

In the COP29 era, food security is crucial. The urban agglomeration in the middle reaches of the Yangtze River (UAMRYR) in China must ensure both food and ecological security. Analyzing the transformation of agricultural land use patterns and their ecological impacts over space and time is essential for improving regional ecological protection and promoting high-quality development. This study starts from the perspective of cropland conversion and is based on data from 31 cities in China's city cluster in the UAMRYR from 2002 to 2022. It analyzes the spatial and temporal distribution of land use structure and cropland conversion, and explores the ecological effects of cropland conversion using a panel fixed model. The results of the study show that: (1) From 2002 to 2022, the spatial distribution pattern of land use in the UAMRYR remained consistent overall, with arable land and forest land dominating, and a significant increase in the area of impervious surfaces. (2) Relative to 2002, the area of arable land transferred out accounted for 11.997% of the total arable land and the area of arable land transferred in accounted for 12.755% of the total arable land. Overall, there is a trend of expansion in arable land. (3) The overall level of urban eco-resilience shows a steady increasing trend, with Jiangxi Province having the best urban eco-resilience, followed by Hunan Province and Hubei Province. (4) The inflow and net increase of cultivated land area play a positive role in promoting urban eco-resilience, while the outflow and conversion to impervious surfaces suppress the ecosystem's resilience against risks. This study conducts a sustained investigation into the ecological effects of cropland conversion across multiple cities, providing empirical evidence to enhance environmental quality and optimize the rational allocation of land resources.

Open Access: Yes

DOI: 10.1002/ldr.70080

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

Mediumship and its Cognitive 'Survival' in Identification of Collective Individuation the Hungarian Painter-Genius Csontváry's Mediumship and 'Survival' Part II. The Hypothesis of Hidden Meaning System of the Picture

Peter Varlaki Judit Ida Steiner-Varlaki Péter Baranyi

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

Publication Date: 2019-10-01

Volume: Unknown

Issue: Unknown

Page Range: 561-566

Description:

The paper deals with the mediumship and the retro-cognitive and precognitive patterns in identification of collective individuation. We attend to show the relationships between the artistic visions (pictures) of Csontváry the Hungarian genius. We continue the discussion with the general hidden mystical theological system of the picture11This paper is dedicated to the blessed memory of Dr. Rezsö Pertorini and Dr. Anthony Storr. Thanks for the inspiration to Dr. Katalin Gellér.

Open Access: Yes

DOI: 10.1109/CogInfoCom47531.2019.9089981

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

Miklós Kuczmann Daniel 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

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

On the positivity of matrix-vector products

Zoltán Horváth

Publication Name: Linear Algebra and Its Applications

Publication Date: 2004-12-01

Volume: 393

Issue: 1-3

Page Range: 253-258

Description:

In this paper we examine the positivity of Rv where R∈R N×N, v∈RN, v≥0 with R=r(τA), r is a given (rational) function, A∈RN×N and τ∈(0,∞). Here we mean by positivity the ordering w.r.t. an arbitrary order cone, which includes the classical entrywise positivity of vectors. Since the requirement R≥0 leads to very severe restrictions on r and τ we construct a positive cone ℘=℘(A) and determine τ*=τ*(r,℘) such that r(τA)℘⊂℘ for all τ∈[0,τ*]. Finally we give an example arising from applications to partial differential equations where our results explain actual computations much better than the general theory on R≥0. © 2004 Elsevier Inc. All rights reserved.

Open Access: Yes

DOI: 10.1016/j.laa.2004.03.012

Mechanical Fatigue Test of Individual Dental Implants

Ibolya Zsoldos Ádám Vörös Klaudia Kulcsár Talabérné

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 501-508

Description:

Since subperiosteal dental implants are custom made implants, design and manufacturing must be carried out with great care, solving comprehensive mechanical analyses. In this work, we performed a 3-day fatigue test on a 3D-printed titanium implant in a custom-designed mechanical testing device. After three days of average chewing loading, no residual deformation was observed. Moreover, no cracks or inclusions were observed when examining the CT scans. Nor did the printing defects on the implant cause any problems. The tested implant showed satisfactory results and was considered to be suitable for implantation. With the case study, we also showed that the new experimental methodology developed for the mechanical examination of subperiosteal implants is suitable for fatigue examinations of implants.

Open Access: Yes

DOI: 10.3233/ATDE240586