TY - JOUR AU - Rajs, Vladimir AU - Herceg, Dejana AU - Despotović, Živadin AU - Bogdanović, Miroslav AU - Šiljegović, Mirjana AU - Popadić, Bane AU - Kiraly, Zoltan AU - Vizvári, Zoltán Ákos AU - Sári, Zoltán AU - Klincsik, Mihály AU - Felde, Imre AU - Odry, Péter AU - Tadity, Vladimir TI - Dead-Time Effect in Inverters on Wireless Power Transfer JF - ELECTRONICS (SWITZ) VL - 13 PY - 2024 IS - 2 PG - 14 SN - 2079-9292 DO - 10.3390/electronics13020304 UR - https://m2.mtmt.hu/api/publication/34496311 ID - 34496311 N1 - Faculty of Technical Sciences, Department of Power, Electronic and Telecommunication Engineering, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad, 21000, Serbia Faculty of Sciences, Department of Physics, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad, 21000, Serbia Institute of Information Technology, University of Dunaujvaros, Tancsics M. Str. 1/A, Dunaujvaros, H-2401, Hungary John von Neumann Faculty of Informatics, University of Obuda, Becsi Str. 96/B, Budapest, H-1034, Hungary Symbolic Methods in Material Analysis and Tomography Research Group, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany Str. 6, Pecs, H-7624, Hungary Faculty of Engineering and Information Technology, University of Pecs, Boszorkany Str. 2, Pecs, H-7624, Hungary Cellular Bioimpedance Research Group, Szentagothai Research Centre, University of Pecs, Ifjusag Str. 20, Pecs, H-7624, Hungary Export Date: 9 February 2024 Correspondence Address: Tadic, V.; Institute of Information Technology, Tancsics M. Str. 1/A, Hungary; email: tadity.laszlo@uni-obuda.hu Funding details: GINOP_PLUSZ-2.1.1-21-2022-00249 Funding text 1: This research was funded by projects 2020-1.1.2-PIACI-KFI-2020-00166 and 2020-1.1.2-PIACI-KFI-2020-00173 of the University of Dunaujavaros and by project GINOP_PLUSZ-2.1.1-21-2022-00249 of the University of Obuda, co-financed by the Hungarian State. AB - This paper presents a comprehensive analysis of the dead-time effects in wireless power transfer systems based on LCC-S topology. In these systems operating at high frequencies, the ratio of dead-time versus the operating period becomes critical, and the dead-time issue can cause certain problems regarding power quality, efficiency, and output voltage ripple. The impact of input quantities such as voltage and switching frequency on the efficiency and output power of the LCC-S-tuned WPT system was also investigated. The optimal combination of these parameters used to achieve the maximum efficiency for a target output power and to set the appropriate value of the dead time were determined by running multiple simulations using the MATLAB R2023b software platform. It was also shown that the output voltage remained unchanged with and without a load and up to 1200 ns of dead-time, which provides a simple implementation of the corresponding mathematical model. In the recommended interval of 600–1500 ns, the influence of the dead-time on the value of the output voltage amplitude is less than 10%. The validity of the proposed method was confirmed through the implementation of the experimental prototype, a 5 kW wireless power transmission system, and the obtained results were in accordance with the simulation results. LA - English DB - MTMT ER - TY - JOUR AU - Vizvári, Zoltán Ákos AU - Klincsik, Mihály AU - Odry, Péter AU - Tadity, Vladimir AU - Győrfi, Nina Rubina AU - Tóth, Attila AU - Sári, Zoltán TI - Continuous Electrode Models and Application of Exact Schemes in Modeling of Electrical Impedance Measurements JF - ELECTRONICS (SWITZ) VL - 13 PY - 2024 IS - 1 PG - 17 SN - 2079-9292 DO - 10.3390/electronics13010066 UR - https://m2.mtmt.hu/api/publication/34448557 ID - 34448557 N1 - Export Date: 22 January 2024 Correspondence Address: Vizvari, Z.; Department of Environmental Engineering, Boszorkany Str. 2, Hungary; email: vizvari.zoltan@mik.pte.hu AB - The crucial issue in electrical impedance (EI) measurements lies in the galvanic interaction between the electrodes and the investigated material. This paper brings together the basic and applied research experience and combines their results with excellent properties. Consequently, innovative precise methodologies have emerged, enabling the direct modeling of EI measurements, free from the inaccuracies often associated with numerical approaches. As an outcome of the efficiency and robustness of the applied method, the conductivity of the material and the electrodes are represented by a common piecewise function, which is used to solve the differential equation modeling of the EI measurement. Moreover, this allows the possibility for modeling the conductivity of electrodes with continuous functions, providing an important generalization of the Complete Electrode Model (CEM), which has been widely used so far. The effectiveness of the novel approach was showcased through two distinct case studies. In the first case study, potential functions within both the material and the electrodes were computed using the CEM. In the second case study, calculations were performed utilizing the newly introduced continuous electrode model. The simulation results suggest that the new method is a powerful tool for biological research, from in vitro experiments to animal studies and human applications. LA - English DB - MTMT ER - TY - JOUR AU - Győrfi, Nina Rubina AU - Gál, Adrián Róbert AU - Fincsur, András AU - Kalmar-Nagy, Karoly AU - Mintál, Kitti AU - Hormay, Edina AU - Miseta, Attila János AU - Tornóczky, Tamás AU - Nemeth, Anita K. AU - Bogner, Péter AU - Kiss, Tamas AU - Helyes, Zsuzsanna AU - Sári, Zoltán AU - Klincsik, Mihály AU - Tadity, Vladimir AU - Lénárd, László AU - Vereczkei, András AU - Karádi, Zoltán György AU - Vizvári, Zoltán Ákos AU - Tóth, Attila TI - Novel Noninvasive Paraclinical Study Method for Investigation of Liver Diseases JF - BIOMEDICINES J2 - BIOMEDICINES VL - 11 PY - 2023 IS - 9 PG - 21 SN - 2227-9059 DO - 10.3390/biomedicines11092449 UR - https://m2.mtmt.hu/api/publication/34124226 ID - 34124226 N1 - Communication AB - Based on a prior university patent, the authors developed a novel type of bioimpedance-based test method to noninvasively detect nonalcoholic fatty liver disease (NAFLD). The development of a new potential NAFLD diagnostic procedure may help to understand the underlying mechanisms between NAFLD and severe liver diseases with a painless and easy-to-use paraclinical examination method, including the additional function to detect even the earlier stages of liver disease. The aim of this study is to present new results and the experiences gathered in relation to NAFLD progress during animal model and human clinical trials. LA - English DB - MTMT ER - TY - JOUR AU - Vizvári, Zoltán Ákos AU - Klincsik, Mihály AU - Odry, Péter AU - Tadity, Vladimir AU - Sári, Zoltán TI - General Exact Schemes for Second-Order Linear Differential Equations Using the Concept of Local Green Functions JF - AXIOMS J2 - AXIOMS VL - 12 PY - 2023 IS - 7 PG - 16 SN - 2075-1680 DO - 10.3390/axioms12070633 UR - https://m2.mtmt.hu/api/publication/34037447 ID - 34037447 N1 - Department of Environmental Engineering, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany str. 2, Pecs, H-7624, Hungary Symbolic Methods in Material Analysis and Tomography Research Group, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany str. 6, Pecs, H-7624, Hungary Cellular Bioimpedance Research Group, Szentagothai Research Centre, University of Pecs, Ifjusag str. 20, Pecs, H-7624, Hungary Department of Technical Informatics, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany str. 6, Pecs, H-7624, Hungary Institute of Information Technology, University of Dunaujvaros, Tancsics M. str. 1/A, Dunaujvaros, H-2401, Hungary John von Neumann Faculty of Informatics, University of Obuda, Becsi str. 96/B, Budapest, H-1034, Hungary Export Date: 7 November 2023 Correspondence Address: Vizvari, Z.; Department of Environmental Engineering, Boszorkany str. 2, Hungary; email: vizvari.zoltan@mik.pte.hu AB - In this paper, we introduce a special system of linear equations with a symmetric, tridiagonal matrix, whose solution vector contains the values of the analytical solution of the original ordinary differential equation (ODE) in grid points. Further, we present the derivation of an exact scheme for an arbitrary mesh grid and prove that its application can completely avoid other errors in discretization and numerical methods. The presented method is constructed on the basis of special local green functions, whose special properties provide the possibility to invert the differential operator of the ODE. Thus, the newly obtained results provide a general, exact solution method for the second-order ODE, which is also effective for obtaining the arbitrary grid, Dirichlet, and/or Neumann boundary conditions. Both the results obtained and the short case study confirm that the use of the exact scheme is efficient and straightforward even for ODEs with discontinuity functions. LA - English DB - MTMT ER - TY - JOUR AU - Sári, Zoltán AU - Klincsik, Mihály AU - Odry, Péter AU - Tadity, Vladimir AU - Tóth, Attila AU - Vizvári, Zoltán Ákos TI - Lumped Element Method Based Conductivity Reconstruction Algorithm for Localization Using Symmetric Discrete Operators on Coarse Meshes JF - SYMMETRY (BASEL) J2 - SYMMETRY-BASEL VL - 15 PY - 2023 IS - 5 PG - 24 SN - 2073-8994 DO - 10.3390/sym15051008 UR - https://m2.mtmt.hu/api/publication/33787514 ID - 33787514 N1 - Department of Technical Informatics, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany Str. 6, Pecs, H-7624, Hungary Symbolic Methods in Material Analysis and Tomography Research Group, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany Str. 6, Pecs, H-7624, Hungary Cellular Bioimpedance Research Group, Szentagothai Research Centre, University of Pecs, Ifjusag Str. 20, Pecs, H-7624, Hungary Institute of Information Technology, University of Dunaujvaros, Tancsics M. Str. 1/A, Dunaujvaros, H-2401, Hungary John von Neumann Faculty of Informatics, University of Obuda, Becsi Str. 96/B, Budapest, H-1034, Hungary Institute of Physiology, Medical School, University of Pecs, Szigeti Str. 12, Pecs, H-7624, Hungary Department of Environmental Engineering, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany Str. 2, Pecs, H-7624, Hungary Cited By :1 Export Date: 7 November 2023 Correspondence Address: Vizvari, Z.; Symbolic Methods in Material Analysis and Tomography Research Group, Boszorkany Str. 6, Hungary; email: vizvari.zoltan@mik.pte.hu AB - The inverse conductivity problem in electrical impedance tomography involves the solving of a nonlinear and under-determined system of equations. This paper presents a new approach, which leads to a quadratic and overdetermined system of equations. The aim of the paper is to establish new research directions in handling of the inverse conductivity problem. The basis of the proposed method is that the material, which can be considered as an isotropic continuum, is modeled as a linear network with concentrated parameters. The weights of the obtained graph represent the properties of the discretized continuum. Further, the application of the developed procedure allows for the dielectric constant to be used in the multi-frequency approach, as a result of which the optimized system of equations always remains overdetermined. Through case studies, the efficacy of the reconstruction method by changing the mesh resolution applied for discretizing is presented and evaluated. The presented results show, that, due to the application of discrete, symmetric mathematical structures, the new approach even at coarse mesh resolution is capable of localizing the inhomogeneities of the material. LA - English DB - MTMT ER - TY - JOUR AU - Kersner, Róbert AU - Klincsik, Mihály AU - Zhanuzakova, Dinara TI - A competition system with nonlinear cross-diffusion: exact periodic patterns JF - REVISTA DE LA REAL ACADEMIA DE CIENCIAS EXACTAS FISICAS Y NATURALES SERIE A-MATEMATICAS J2 - RACSAM REV R ACAD A VL - 116 PY - 2022 IS - 4 PG - 11 SN - 1578-7303 DO - 10.1007/s13398-022-01299-1 UR - https://m2.mtmt.hu/api/publication/33236539 ID - 33236539 AB - Our concern in this paper is to shed some additional light on the mechanism and the effect caused by the so called cross-diffusion. We consider a two-species reaction-diffusion (RD) system. Both "fluxes" contain the gradients of both unknown solutions. We show that-for some parameter range- there exist two different type of periodic stationary solutions. Using them, we are able to divide into parts the (eight-dimensional) parameter space and indicate the so called Turing domains where our solutions exist. The boundaries of these domains, in analogy with "bifurcation point", called "bifurcation surfaces". As it is commonly believed, these solutions are limits as t goes to infinity of the solutions of corresponding evolution system. In a forthcoming paper we shall give a detailed account about our numerical results concerning different kind of stability. Here we also show some numerical calculations making plausible that our solutions are in fact attractors with a large domain of attraction in the space of initial functions. LA - English DB - MTMT ER - TY - CHAP AU - Odry, Ákos AU - Vizvári, Zoltán Ákos AU - Győrfi, Nina Rubina AU - Kovács, Levente AU - Eigner, György AU - Klincsik, Mihály AU - Sári, Zoltán AU - Odry, Péter AU - Tóth, Attila ED - Tóth, Attila ED - Vizvári, Zoltán Ákos TI - Heurisztikus optimalizálás alkalmazása a bioimpedancia spektroszkópiás kiértékelésben T2 - Orvosbiológiai kérdések - multidiszciplináris, bioimpedancia alapú válaszok PB - Pécsi Tudományegyetem CY - Pécs SN - 9789634299349 PY - 2022 SP - 21 EP - 34 PG - 14 UR - https://m2.mtmt.hu/api/publication/32732764 ID - 32732764 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Tadity, Vladimir AU - Tóth, Attila AU - Vizvári, Zoltán Ákos AU - Klincsik, Mihály AU - Sári, Zoltán AU - Sarcevic, Péter AU - Sárosi, József AU - Bíró, István TI - Perspectives of RealSense and ZED Depth Sensors for Robotic Vision Applications JF - MACHINES J2 - MACHINES VL - 10 PY - 2022 IS - 3 PG - 26 SN - 2075-1702 DO - 10.3390/machines10030183 UR - https://m2.mtmt.hu/api/publication/32718606 ID - 32718606 N1 - Institute of Information Technology, University of Dunaujvaros, Tancsics Mihaly u. 1/A Pf.: 152, Dunaujvaros, H-2401, Hungary Institute of Physiology, Medical School, University of Pecs, Szigeti Str. 12, Pecs, H-7624, Hungary Department of Environmental Engineering, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany Str. 2, Pecs, H-7624, Hungary Department of Technical Informatics, Faculty of Engineering and Information Technology, University of Pecs, Boszorkany Str. 2, Pecs, H-7624, Hungary Faculty of Engineering, University of Szeged, Mars ter 7, Szeged, H-6724, Hungary Cited By :12 Export Date: 7 November 2023 Correspondence Address: Tadic, V.; Institute of Information Technology, Tancsics Mihaly u. 1/A Pf.: 152, Hungary; email: laslo.tadic@gmail.com Funding details: European Commission, EC Funding details: Pécsi Tudományegyetem, PTE, 2020-1.1.2-PIACI-KFI-2020-00173, CPV 731100000-6, CPV 73120000-9 Funding text 1: RealSense technology comprises a microprocessor for image processing, a module for creating depth images, an IR emitter, a segment for tracking movements, and depth sensors. These depth sensors are built on deep scanning technology, which allows devices to see shapes and objects in the same manner as humans. The complete hardware is also supported by appropriate open-source Software Development Kit (SDK) software called librealsense [7]. This software platform provides simple software support for all RealSense cameras. The software platform supports C/C++, ROS (Robot Operating System), Python, MATLAB, etc., systems and programming languages for the development of appropriate and various applications. Intel also provides two applications for the setup and use of the cameras [8]. AB - This review paper presents an overview of depth cameras. Our goal is to describe the features and capabilities of the introduced depth sensors in order to determine their possibilities in robotic applications, focusing on objects that might appear in applications with high accuracy requirements. A series of experiments was conducted, and various depth measuring conditions were examined in order to compare the measurement results of all the depth cameras. Based on the results, all the examined depth sensors were appropriate for applications where obstacle avoidance and robot spatial orientation were required in coexistence with image vision algorithms. In robotic vision applications where high accuracy and precision were obligatory, the ZED depth sensors achieved better measurement results. LA - English DB - MTMT ER - TY - JOUR AU - Vizvári, Zoltán Ákos AU - Klincsik, Mihály AU - Sári, Zoltán AU - Odry, Péter TI - Lumped Element Method. A Discrete Calculus Approach for Solving Elliptic and Parabolic PDEs TS - A Discrete Calculus Approach for Solving Elliptic and Parabolic PDEs JF - ACTA POLYTECHNICA HUNGARICA J2 - ACTA POLYTECH HUNG VL - 18 PY - 2021 IS - 7 SP - 201 EP - 223 PG - 23 SN - 1785-8860 DO - 10.12700/APH.18.7.2021.7.11 UR - https://m2.mtmt.hu/api/publication/32149186 ID - 32149186 N1 - University of Pécs, Szentágothai Research Centre, Ifjúság útja 20, Pécs, H-7624, Hungary University of Dunaújváros, Institute of Information Technology, Táncsics M. u. 1/A, Dunaújváros, H-2401, Hungary Cited By :11 Export Date: 6 October 2022 LA - English DB - MTMT ER - TY - CHAP AU - Odry, Ákos AU - Vizvári, Zoltán Ákos AU - Győrfi, Nina Rubina AU - Kovács, Levente AU - Eigner, György AU - Klincsik, Mihály AU - Sari, Zoltan AU - Odry, Péter AU - Tóth, Attila ED - Szakál, Anikó TI - Application of Heuristic Optimization in Bioimpedance Spectroscopy Evaluation T2 - 15th IEEE International Symposium on Applied Computational Intelligence and Informatics SACI 2021 PB - IEEE CY - Budapest CY - Piscataway (NJ) SN - 9781728195438 PY - 2021 SP - 000105 EP - 000112 PG - 8 DO - 10.1109/SACI51354.2021.9465617 UR - https://m2.mtmt.hu/api/publication/32092177 ID - 32092177 N1 - Export Date: 21 September 2021 AB - As material analysis method, the bioimpedance spectroscopy (BIS) is an effective technique to obtain material characteristics in many biological applications. Among the BIS models, the single-dispersion RC model and the Cole-Cole model constitute the fundamental mathematical descriptions for BIS measurements. These models enable both the evaluation of impedance spectrum and derivation of core parameters that describe biological processes. This paper presents the application of the particle swarm optimization (PSO), as a flexible heuristic optimization approach, to both derive the model parameters and characterize biological media based on BIS measurements. First, the fundamental modeling approaches are addressed and the core parameters arc discussed. Moreover, the employed electrical impedance measuring instrument and conducted experiments are presented. Then, a multi-objective fitness function is established for the usage of the PSO algorithm for model parameter optimization. The paper demonstrates two case studies, namely, BIS measurements are performed to monitor i) liver fat and characterize its state with an optimized Cole-Cole model and ii) cell culture growth and characterize its state with an optimized single-dispersion RC model. It is shown with experimental results that PSO is an effective and robust tool to fit these biological models to BIS measurements. Additionally, the experimental results also highlight that the cell culture growth process cannot be modeled properly with the single-dispersion RC model in high frequency ranges. This experimental observation establishes the demand for the derivation of a more sophisticated mathematical model for the comprehensive characterization of cell culture growth in wide frequency spectrum. LA - English DB - MTMT ER -