Gyula Mester | University of Szeged (original) (raw)
Papers by Gyula Mester
Interdisciplinary Description of Complex Systems, Feb 21, 2022
IGI Global eBooks, 2011
The market favors the best-selling computer games regardless of their social and educational effe... more The market favors the best-selling computer games regardless of their social and educational effects. This chapter will discuss the present trends in educational games development, technologies related to them as well as their features, through representative examples of games used for education with respect to pedagogical, business, and social aspects. Benefits and limitations of introducing games in education will be pointed out. Computer games for the disabled along with their pedagogical and social effects will be presented. Recent research results on the implementation of video games in schools and educational game evaluation will be presented in the chapter, based on the experience in the development, implementation, and evaluation of several interactive e-learning educational exercises, as well as in the development and validation of several innovative computer games for the visually impaired.
Interdisciplinary Description of Complex Systems, 2016
Recently, the requirement for learning is constantly increasing. MOOCmassive open online courses ... more Recently, the requirement for learning is constantly increasing. MOOCmassive open online courses represent educational revolution of the century. A MOOC is an online course accessible to unlimited number of participation and is an open access via the web.
FME Transactions, 2020
This paper will present an overview of indoor and outdoor drone localization methods. Outdoor sce... more This paper will present an overview of indoor and outdoor drone localization methods. Outdoor scenarios almost always use a GPS with IMU. Indoor systems are using short-range sensors that are sensitive to the external conditions of the environment. Mostly used methods are optical flow and stereovision, while an ultrasonic transceiver system optimizes and provides high precision and orientation of the drone. An ultrasonic preceptor is integrated into a listener/beacon and can be used with referenced beacons inside a WSN. The Crossbow Cricket hardware platform, which is based on TDOA and RSS principle, is used for simulations and code development. The researched direction is the localization of referent nodes (beacons) concerning the listener which is mounted on a flying drone. For that purpose, a probabilistic approach is used, based on a Bayes filter, where the positions of the beacon can be observed like random variables. Considering that these distributions significantly vary from a Gauss distribution, it is appropriate to use a particle filter.
Interdisciplinary Description of Complex Systems, 2019
This article will show an overview of the model and simulations of general cardio pediatrics case... more This article will show an overview of the model and simulations of general cardio pediatrics cases. To avoid simulated interference, Kalman and lowpass filter blocks are placed. In pediatric cases normal ECG (Electrocardiogram) curve is a bit different in relation to the middle-age persons. In cardio pediatric is represented especially the ECG curve with higher beats/min. Depending on the age of the child's heart rate is variable. Therefore, identifying irregularities of the heart rate in children should be implemented a particular type of filter to eliminate rough measurement error on measurement signals. The model is obtained computationally shown in the examples of simulation in LabView and Java application programming interfaces. The model realization of the ECG signal is based on a few methods. Therefore, it selected only one method to display a simulated ECG signal. Installation of additional software filters allows us for realistic expectations after hardware integration. The real practical case is provided by a developed system with compiled firmware in the microcontroller. Firmware defines the behavior of the ECG signal after the integration of Kalman and the lowpass filter. Some cardio pediatric cases are processed with the method which can be applied Kalman or lowpass filter.
Interdisciplinary Description of Complex Systems, 2018
Noise pollution is one of the most relevant problems in urban area. The main source of noise poll... more Noise pollution is one of the most relevant problems in urban area. The main source of noise pollution is the number and type of motor vehicles, but other parameters depending on street configuration yield to a system hardly to be exactly modelled by classical mathematical methods. Smart cities are expected to dynamically control the urban traffic to reduce not just traffic jams, but also to ensure a comfortable noise level for inhabitants. This article gives a design method for efficient genetic fuzzy modelling of traffic generated smart cities noise pollution based on fuzzy logic, multi objective genetic algorithm, gradient descent optimisation and singular value decomposition in the MATLAB environment. Genetic algorithms with objectives to minimise the maximum absolute identification error, the root mean square of the identification error, reduce model complexity and ensure maximal numerical robustness are applied to Zadeh type fuzzy partition membership function parameters preliminary identification, and then gradient descent method is used for their fine-tuning optimization, while the fuzzy rule consequence linear parameters are calculated by singular value decomposition method to find the least squares optimal training data fitting of the model. The training data set is built from measured data, combined with carefully selected simulation data to ensure the completeness of the model and its numerical robustness. Detailed analysis of the method and results by computer simulation of the identification process show the validity of the proposed method.
In this paper, a high-precision algorithm for parameter identification of nonlinear multivariable... more In this paper, a high-precision algorithm for parameter identification of nonlinear multivariable dynamic systems is proposed. The proposed computational approach is based on the following assumptions: a) system is nonlinearly parameterized by a vector of unknown system parameters; b) only partial measurement of system state is available; c) there are no state observers; d) initial conditions are unknown except for measurable system states. The identification problem is formulated as a continuous dynamic optimization problem which is discretized by higher-order Adams method and numerically solved by a backward-in-time recurrent algorithm which is similar to the backpropagation-through-time (BPTT) algorithm. The proposed algorithm is especially effective for identification of homogenous spatially distributed nonlinear systems what is demonstrated on the parameter identification of a multi-degree-of-freedom torsional system with nonlinearly parameterized elastic forces, unknown initial velocities and positions measurement only.
Tehnika, 2021
The objective of this paper is to examine the types of autonomous vehicles already employed in tr... more The objective of this paper is to examine the types of autonomous vehicles already employed in transportation. It exemplifies the segments of transportation which already use autonomous vehicles. This paper gives an insight of the places in the world where autonomous vehicles are put in use. Furthermore, companies such as Volvo, Volkswagen, Airbus and WAYMO have showed their models of driverless vehicles ranging from trucks, buses, shuttles and helicopters. Moreover, the paper provides a description, testing methods, use and features of the each vehicle presented. In short, this paper aims to raise consciousness about the future of not just public transportation but also transportation of any other type such as good's transportation, delivery, vehicles provided for sightseeing, aircrafts etc.
Springer eBooks, 2013
ABSTRACT
Acta Mechanica, Mar 7, 2016
In this paper, oscillators with asymmetric and symmetric quadratic nonlinearity are compared. Bot... more In this paper, oscillators with asymmetric and symmetric quadratic nonlinearity are compared. Both oscillators are modeled as ordinary second-order differential equations with strong quadratic nonlinearities: one with positive quadratic term and the second with a quadratic term which changes the sign. Solutions for both equations are obtained in the form of Jacobi elliptic functions. For the asymmetric oscillator, conditions for the periodic motion are determined, while for the symmetric oscillator a new approximate solution procedure based on averaging is developed. Obtained results are tested on an optomechanical system where the motion of a cantilever in the intracavity field is oscillatory. Two types of quadratic nonlinearities in the system are investigated: symmetric and asymmetric. The advantage and disadvantage of both models is discussed. The analytical procedure suggested in the paper is applied. The obtained solution agrees well with a numerical one.
Interdisciplinary Description of Complex Systems, Dec 30, 2022
The impact factor of scientific journals and the h-index depend on the citations. Therefore, the ... more The impact factor of scientific journals and the h-index depend on the citations. Therefore, the citation analysis is a very important part of scientometrics. The paper presents the 2022 ranking list of citation analysis researchers. The ranking is presented primarily according to the h-index of researchers. The advantage the h-index is that it combines both the quantitynumber of articles and qualitycitations to these articles. A researcher cannot have a high h-index without publishing a considerable number of articles. The h-index favors researchers that publish a continuous stream of articles. Researchers with the same h-index are ranked by the number of citations. The minimum h-index of the 10 ranked researchers is 26. h-index can be determined from the following online databases: Web of Science, Scopus, Google Scholar and the Publish or Perish program. The ranking is edited using the Google Scholar database.
The Science Citation Index (SCI Ⓡ) was first presented in Science in 1955. The Annual SCI Journal... more The Science Citation Index (SCI Ⓡ) was first presented in Science in 1955. The Annual SCI Journal Citation Reports were officially launched in 1975. The SCI’s multidisciplinary database has two purposes: first, to identify what each scientist has published, and second, where and how often the papers by that scientist are cited. Hence, the SCI has always been divided into two author-based parts: the Source Author Index and the Citation Index. By extension, one can also determine what each institution and country has published and how often their papers are cited. The Web of Science Ⓡ(WoS)—the SCI’s electronic version—links these two functions: an author’s publication can be listed by chronology, by journal, or by citation frequency. The Science Citation Index was launched in 1964 and the Annual SCI Journal Citation Reports were officially launched in 1975. The impact factor was devised by Eugene Garfield: in any given year, the impact factor of a journal is the number of citations, received in that year, of articles published in that journal during the two preceding years, divided by the total number of articles published in that journal during the two preceding years. The definition of the impact factor has been implemented on the evaluation of the impact factor of the journal: Interdisciplinary Description of Complex Systems.)
Transactions of Famena, Jun 16, 2018
This paper presents a numerical simulation of a pulsating flow generated inside an ejector; the f... more This paper presents a numerical simulation of a pulsating flow generated inside an ejector; the flow is intended to oxidize ferrous iron (Fe 2+) dissolved in drinking water to ferric iron (Fe 3+). The pulsating flow ejector can be used in water treatment systems where the water is saturated with oxygen before being treated by filters. It is shown that the pulsating flow is generated due to fluctuations in the pressure, density, and velocity of the flow inside the ejector. It is established that the flow pressure inside the ejector varies from 0.513 to 0.0719 MPa, the flow density varies from 4.64 to 0.66 kg/m 3 , and the flow velocity varies from 0 to 590 m/s. Numerical simulation results have shown that an acoustic field is generated inside the ejector during the mixing of air with water, which accelerates the coagulation of iron particles. The obtained sound power level value of 100 dB shows that the pulsating flow ejector can be used for non-reagent water treatment.
FME Transactions, 2017
In this paper, a novel fuzzy identification method for dynamic modelling of quadrotors UAV is pre... more In this paper, a novel fuzzy identification method for dynamic modelling of quadrotors UAV is presented. The method is based on a special parameterization of the antecedent part of fuzzy systems that results in fuzzy-partitions for antecedents. This antecedent parameter representation method of fuzzy rules ensures upholding of predefined linguistic value ordering and ensures that fuzzy-partitions remain intact throughout an unconstrained hybrid evolutionary and gradient descent based optimization process. In the equations of motion the first order derivative component is calculated based on Christoffel symbols, the derivatives of fuzzy systems are used for modelling the Coriolis effects, gyroscopic and centrifugal terms. The non-linear parameters are subjected to an initial global evolutionary optimization scheme and fine tuning with gradient descent based local search. Simulation results of the proposed new quadrotor dynamic model identification method are promising.
Interdisciplinary Description of Complex Systems, 2016
Indexes in scientometrics are based on citations. However, in contrast to the journal impact fact... more Indexes in scientometrics are based on citations. However, in contrast to the journal impact factor, which gives only the ranking of the scientific journals, ordered by impact factor, indexes in scientometrics are suitable for ranking of scientists, scientific journals and countries. In this paper the h-index, h5-index, the World ranking the top of 25 Highly Cited Researchers (h > 100) and the ranking of 25 scientists in Hungarian Institutions according to their Google Scholar Citations public profiles are considered. These indexes (h5-index) are applied for making of the list of top 20 publications (journals and proceedings) in the field of Robotics. The World ranking is done of the best 50 countries according to h-index in year 2014. Data are obtained from the portal Scimago.
Tehnika, 2021
In this paper, we would discuss a bit more how cyber technologies operate in a physical way and w... more In this paper, we would discuss a bit more how cyber technologies operate in a physical way and why it's important to understand the limitations of a physical reality. So commonlymathematical terms would get assumed as abstractso they could be considered as somehow perfect. On the other hand, the reality would offer many boundaries and obstacles that should be avoided or better explained. As it's known, cyber technologies belong to digital systems containing so many electronic components that would have their physical performances. Those performances as well as the entire cyber defense of such digital technologies would be analyzed deeper through this effort.
Interdisciplinary Description of Complex Systems, 2017
Using the h-index and the total number of citations in (natural) sciences, techniques and humanit... more Using the h-index and the total number of citations in (natural) sciences, techniques and humanities in this article the best 10 Croatian researchers is ranked. The list may be formed based on the h-index and the total number of citations, given in Web of Science, Scopus, Publish or Perish Program and Google Scholar. Data for the first 10 researchers are presented. Google Scholar is the most complete. Therefore, to define a single indicator, h-index calculated by Google Scholar may be a good and simple one. The author chooses the Google Scholar database as it is the broadest one.
Interdisciplinary Description of Complex Systems, Feb 21, 2022
IGI Global eBooks, 2011
The market favors the best-selling computer games regardless of their social and educational effe... more The market favors the best-selling computer games regardless of their social and educational effects. This chapter will discuss the present trends in educational games development, technologies related to them as well as their features, through representative examples of games used for education with respect to pedagogical, business, and social aspects. Benefits and limitations of introducing games in education will be pointed out. Computer games for the disabled along with their pedagogical and social effects will be presented. Recent research results on the implementation of video games in schools and educational game evaluation will be presented in the chapter, based on the experience in the development, implementation, and evaluation of several interactive e-learning educational exercises, as well as in the development and validation of several innovative computer games for the visually impaired.
Interdisciplinary Description of Complex Systems, 2016
Recently, the requirement for learning is constantly increasing. MOOCmassive open online courses ... more Recently, the requirement for learning is constantly increasing. MOOCmassive open online courses represent educational revolution of the century. A MOOC is an online course accessible to unlimited number of participation and is an open access via the web.
FME Transactions, 2020
This paper will present an overview of indoor and outdoor drone localization methods. Outdoor sce... more This paper will present an overview of indoor and outdoor drone localization methods. Outdoor scenarios almost always use a GPS with IMU. Indoor systems are using short-range sensors that are sensitive to the external conditions of the environment. Mostly used methods are optical flow and stereovision, while an ultrasonic transceiver system optimizes and provides high precision and orientation of the drone. An ultrasonic preceptor is integrated into a listener/beacon and can be used with referenced beacons inside a WSN. The Crossbow Cricket hardware platform, which is based on TDOA and RSS principle, is used for simulations and code development. The researched direction is the localization of referent nodes (beacons) concerning the listener which is mounted on a flying drone. For that purpose, a probabilistic approach is used, based on a Bayes filter, where the positions of the beacon can be observed like random variables. Considering that these distributions significantly vary from a Gauss distribution, it is appropriate to use a particle filter.
Interdisciplinary Description of Complex Systems, 2019
This article will show an overview of the model and simulations of general cardio pediatrics case... more This article will show an overview of the model and simulations of general cardio pediatrics cases. To avoid simulated interference, Kalman and lowpass filter blocks are placed. In pediatric cases normal ECG (Electrocardiogram) curve is a bit different in relation to the middle-age persons. In cardio pediatric is represented especially the ECG curve with higher beats/min. Depending on the age of the child's heart rate is variable. Therefore, identifying irregularities of the heart rate in children should be implemented a particular type of filter to eliminate rough measurement error on measurement signals. The model is obtained computationally shown in the examples of simulation in LabView and Java application programming interfaces. The model realization of the ECG signal is based on a few methods. Therefore, it selected only one method to display a simulated ECG signal. Installation of additional software filters allows us for realistic expectations after hardware integration. The real practical case is provided by a developed system with compiled firmware in the microcontroller. Firmware defines the behavior of the ECG signal after the integration of Kalman and the lowpass filter. Some cardio pediatric cases are processed with the method which can be applied Kalman or lowpass filter.
Interdisciplinary Description of Complex Systems, 2018
Noise pollution is one of the most relevant problems in urban area. The main source of noise poll... more Noise pollution is one of the most relevant problems in urban area. The main source of noise pollution is the number and type of motor vehicles, but other parameters depending on street configuration yield to a system hardly to be exactly modelled by classical mathematical methods. Smart cities are expected to dynamically control the urban traffic to reduce not just traffic jams, but also to ensure a comfortable noise level for inhabitants. This article gives a design method for efficient genetic fuzzy modelling of traffic generated smart cities noise pollution based on fuzzy logic, multi objective genetic algorithm, gradient descent optimisation and singular value decomposition in the MATLAB environment. Genetic algorithms with objectives to minimise the maximum absolute identification error, the root mean square of the identification error, reduce model complexity and ensure maximal numerical robustness are applied to Zadeh type fuzzy partition membership function parameters preliminary identification, and then gradient descent method is used for their fine-tuning optimization, while the fuzzy rule consequence linear parameters are calculated by singular value decomposition method to find the least squares optimal training data fitting of the model. The training data set is built from measured data, combined with carefully selected simulation data to ensure the completeness of the model and its numerical robustness. Detailed analysis of the method and results by computer simulation of the identification process show the validity of the proposed method.
In this paper, a high-precision algorithm for parameter identification of nonlinear multivariable... more In this paper, a high-precision algorithm for parameter identification of nonlinear multivariable dynamic systems is proposed. The proposed computational approach is based on the following assumptions: a) system is nonlinearly parameterized by a vector of unknown system parameters; b) only partial measurement of system state is available; c) there are no state observers; d) initial conditions are unknown except for measurable system states. The identification problem is formulated as a continuous dynamic optimization problem which is discretized by higher-order Adams method and numerically solved by a backward-in-time recurrent algorithm which is similar to the backpropagation-through-time (BPTT) algorithm. The proposed algorithm is especially effective for identification of homogenous spatially distributed nonlinear systems what is demonstrated on the parameter identification of a multi-degree-of-freedom torsional system with nonlinearly parameterized elastic forces, unknown initial velocities and positions measurement only.
Tehnika, 2021
The objective of this paper is to examine the types of autonomous vehicles already employed in tr... more The objective of this paper is to examine the types of autonomous vehicles already employed in transportation. It exemplifies the segments of transportation which already use autonomous vehicles. This paper gives an insight of the places in the world where autonomous vehicles are put in use. Furthermore, companies such as Volvo, Volkswagen, Airbus and WAYMO have showed their models of driverless vehicles ranging from trucks, buses, shuttles and helicopters. Moreover, the paper provides a description, testing methods, use and features of the each vehicle presented. In short, this paper aims to raise consciousness about the future of not just public transportation but also transportation of any other type such as good's transportation, delivery, vehicles provided for sightseeing, aircrafts etc.
Springer eBooks, 2013
ABSTRACT
Acta Mechanica, Mar 7, 2016
In this paper, oscillators with asymmetric and symmetric quadratic nonlinearity are compared. Bot... more In this paper, oscillators with asymmetric and symmetric quadratic nonlinearity are compared. Both oscillators are modeled as ordinary second-order differential equations with strong quadratic nonlinearities: one with positive quadratic term and the second with a quadratic term which changes the sign. Solutions for both equations are obtained in the form of Jacobi elliptic functions. For the asymmetric oscillator, conditions for the periodic motion are determined, while for the symmetric oscillator a new approximate solution procedure based on averaging is developed. Obtained results are tested on an optomechanical system where the motion of a cantilever in the intracavity field is oscillatory. Two types of quadratic nonlinearities in the system are investigated: symmetric and asymmetric. The advantage and disadvantage of both models is discussed. The analytical procedure suggested in the paper is applied. The obtained solution agrees well with a numerical one.
Interdisciplinary Description of Complex Systems, Dec 30, 2022
The impact factor of scientific journals and the h-index depend on the citations. Therefore, the ... more The impact factor of scientific journals and the h-index depend on the citations. Therefore, the citation analysis is a very important part of scientometrics. The paper presents the 2022 ranking list of citation analysis researchers. The ranking is presented primarily according to the h-index of researchers. The advantage the h-index is that it combines both the quantitynumber of articles and qualitycitations to these articles. A researcher cannot have a high h-index without publishing a considerable number of articles. The h-index favors researchers that publish a continuous stream of articles. Researchers with the same h-index are ranked by the number of citations. The minimum h-index of the 10 ranked researchers is 26. h-index can be determined from the following online databases: Web of Science, Scopus, Google Scholar and the Publish or Perish program. The ranking is edited using the Google Scholar database.
The Science Citation Index (SCI Ⓡ) was first presented in Science in 1955. The Annual SCI Journal... more The Science Citation Index (SCI Ⓡ) was first presented in Science in 1955. The Annual SCI Journal Citation Reports were officially launched in 1975. The SCI’s multidisciplinary database has two purposes: first, to identify what each scientist has published, and second, where and how often the papers by that scientist are cited. Hence, the SCI has always been divided into two author-based parts: the Source Author Index and the Citation Index. By extension, one can also determine what each institution and country has published and how often their papers are cited. The Web of Science Ⓡ(WoS)—the SCI’s electronic version—links these two functions: an author’s publication can be listed by chronology, by journal, or by citation frequency. The Science Citation Index was launched in 1964 and the Annual SCI Journal Citation Reports were officially launched in 1975. The impact factor was devised by Eugene Garfield: in any given year, the impact factor of a journal is the number of citations, received in that year, of articles published in that journal during the two preceding years, divided by the total number of articles published in that journal during the two preceding years. The definition of the impact factor has been implemented on the evaluation of the impact factor of the journal: Interdisciplinary Description of Complex Systems.)
Transactions of Famena, Jun 16, 2018
This paper presents a numerical simulation of a pulsating flow generated inside an ejector; the f... more This paper presents a numerical simulation of a pulsating flow generated inside an ejector; the flow is intended to oxidize ferrous iron (Fe 2+) dissolved in drinking water to ferric iron (Fe 3+). The pulsating flow ejector can be used in water treatment systems where the water is saturated with oxygen before being treated by filters. It is shown that the pulsating flow is generated due to fluctuations in the pressure, density, and velocity of the flow inside the ejector. It is established that the flow pressure inside the ejector varies from 0.513 to 0.0719 MPa, the flow density varies from 4.64 to 0.66 kg/m 3 , and the flow velocity varies from 0 to 590 m/s. Numerical simulation results have shown that an acoustic field is generated inside the ejector during the mixing of air with water, which accelerates the coagulation of iron particles. The obtained sound power level value of 100 dB shows that the pulsating flow ejector can be used for non-reagent water treatment.
FME Transactions, 2017
In this paper, a novel fuzzy identification method for dynamic modelling of quadrotors UAV is pre... more In this paper, a novel fuzzy identification method for dynamic modelling of quadrotors UAV is presented. The method is based on a special parameterization of the antecedent part of fuzzy systems that results in fuzzy-partitions for antecedents. This antecedent parameter representation method of fuzzy rules ensures upholding of predefined linguistic value ordering and ensures that fuzzy-partitions remain intact throughout an unconstrained hybrid evolutionary and gradient descent based optimization process. In the equations of motion the first order derivative component is calculated based on Christoffel symbols, the derivatives of fuzzy systems are used for modelling the Coriolis effects, gyroscopic and centrifugal terms. The non-linear parameters are subjected to an initial global evolutionary optimization scheme and fine tuning with gradient descent based local search. Simulation results of the proposed new quadrotor dynamic model identification method are promising.
Interdisciplinary Description of Complex Systems, 2016
Indexes in scientometrics are based on citations. However, in contrast to the journal impact fact... more Indexes in scientometrics are based on citations. However, in contrast to the journal impact factor, which gives only the ranking of the scientific journals, ordered by impact factor, indexes in scientometrics are suitable for ranking of scientists, scientific journals and countries. In this paper the h-index, h5-index, the World ranking the top of 25 Highly Cited Researchers (h > 100) and the ranking of 25 scientists in Hungarian Institutions according to their Google Scholar Citations public profiles are considered. These indexes (h5-index) are applied for making of the list of top 20 publications (journals and proceedings) in the field of Robotics. The World ranking is done of the best 50 countries according to h-index in year 2014. Data are obtained from the portal Scimago.
Tehnika, 2021
In this paper, we would discuss a bit more how cyber technologies operate in a physical way and w... more In this paper, we would discuss a bit more how cyber technologies operate in a physical way and why it's important to understand the limitations of a physical reality. So commonlymathematical terms would get assumed as abstractso they could be considered as somehow perfect. On the other hand, the reality would offer many boundaries and obstacles that should be avoided or better explained. As it's known, cyber technologies belong to digital systems containing so many electronic components that would have their physical performances. Those performances as well as the entire cyber defense of such digital technologies would be analyzed deeper through this effort.
Interdisciplinary Description of Complex Systems, 2017
Using the h-index and the total number of citations in (natural) sciences, techniques and humanit... more Using the h-index and the total number of citations in (natural) sciences, techniques and humanities in this article the best 10 Croatian researchers is ranked. The list may be formed based on the h-index and the total number of citations, given in Web of Science, Scopus, Publish or Perish Program and Google Scholar. Data for the first 10 researchers are presented. Google Scholar is the most complete. Therefore, to define a single indicator, h-index calculated by Google Scholar may be a good and simple one. The author chooses the Google Scholar database as it is the broadest one.