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Dr. Jan Valíček
1. Institute of Technology and Business in České Budějovice, Okružní 10, 370 01 České Budějovice, Czech Republic

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0 Advanced Materials
0 Applied Physics
0 Coatings
0 Mechanical Properties
0 Surface Engineering

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Journal article
Published: 23 June 2021 in Sustainability
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The European Union Quality policy promotes original and traditional agricultural and food products of high quality at the EU level. It aims at protecting the names of specific products to promote their unique characteristics, linked to their geographical origin, traditional know-how and local culture. In May 2020, the European Commission launched the EU-wide public consultation on its promotion policy for agricultural and food products to get feedback from citizens and stakeholders on the effectiveness, efficiency and relevance of the current measures, as well as their coherence with EU action in other areas and the added value of this kind of policy being implemented at the EU level. The article is focused on the evaluation effectiveness of the implementation of the EU Quality Policy in Slovakia, covering the territory of the whole country and the aim of this evaluation is to assess the level of awareness in Slovakia regarding the EU Quality policy implementation and the positive and negative experiences with its implementation at the national level. The evaluation period covers all 17 years of its implementation from its introduction in June 2003. Special attention is given to what needs to be done to improve its implementation in Slovakia and to increase the number of Slovak products holding this prestigious label. The main issue that came out of the evaluation process is very poor information on EU Quality Policy implementation in Slovakia. Currently, there is only a website run by the Ministry of Agriculture and Rural Development of the Slovak Republic. There is not much motivation for producers to have an interest in the registration process. Therefore, priority should be given to overcoming this.

ACS Style

Zuzana Palková; Marieta Okenková; Marta Harničárová; Jan Valíček; Miroslav Gombár; Jakub Dvorský; Mária Behanovská; Monika Slaninová; Monika Reiskupová; Peter Vnučko. Implementation of the EU Quality Policy: Case Study, Slovakia. Sustainability 2021, 13, 7073 .

AMA Style

Zuzana Palková, Marieta Okenková, Marta Harničárová, Jan Valíček, Miroslav Gombár, Jakub Dvorský, Mária Behanovská, Monika Slaninová, Monika Reiskupová, Peter Vnučko. Implementation of the EU Quality Policy: Case Study, Slovakia. Sustainability. 2021; 13 (13):7073.

Chicago/Turabian Style

Zuzana Palková; Marieta Okenková; Marta Harničárová; Jan Valíček; Miroslav Gombár; Jakub Dvorský; Mária Behanovská; Monika Slaninová; Monika Reiskupová; Peter Vnučko. 2021. "Implementation of the EU Quality Policy: Case Study, Slovakia." Sustainability 13, no. 13: 7073.

Journal article
Published: 03 June 2021 in Materials
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The combination of stamping and subsequent welding of components is an important area of the automotive industry. Stamping inaccuracies affect the final size of the stamping and the welded part. In this article, we deal with a specific component that is produced by such a procedure and is also a common part of the geometry of a car. We focused on the possibility of using a negative phenomenon—deformation during welding—on the partial elimination of inaccuracies arising during stamping. Based on the planned experiment, we created a prediction model for the selected part and its production, with the help of which it is possible to determine suitable welding parameters for a specific dimension of the stamping and the required monitored dimension of the welded part. The article also includes the results of additional experimental measurements verifying the accuracy of the model and prediction maps for practice.

ACS Style

Milan Kadnár; Peter Káčer; Marta Harničárová; Jan Valíček; Mirek Gombár; Milena Kušnerová; František Tóth; Marian Boržan; Juraj Rusnák. Prediction Model of the Resulting Dimensions of Welded Stamped Parts. Materials 2021, 14, 3062 .

AMA Style

Milan Kadnár, Peter Káčer, Marta Harničárová, Jan Valíček, Mirek Gombár, Milena Kušnerová, František Tóth, Marian Boržan, Juraj Rusnák. Prediction Model of the Resulting Dimensions of Welded Stamped Parts. Materials. 2021; 14 (11):3062.

Chicago/Turabian Style

Milan Kadnár; Peter Káčer; Marta Harničárová; Jan Valíček; Mirek Gombár; Milena Kušnerová; František Tóth; Marian Boržan; Juraj Rusnák. 2021. "Prediction Model of the Resulting Dimensions of Welded Stamped Parts." Materials 14, no. 11: 3062.

Journal article
Published: 16 May 2021 in Materials
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The formulation of the Hall–Petch relationship in the early 1950s has raised immense interest in studying the influence of the grain size of solid materials on their properties. Grain refinement can be achieved through extreme deformation. In the presented study, Equal-Channel Angular Pressing (ECAP) was successfully applied to produce an ultrafine-grained microstructure in a pure commercial Cu of 99.9 wt%. Samples were processed by ECAP at 21 °C for six passes via route A. A new equation of equilibrium that allows the exact determination of the number of extrusions and other technological parameters required to achieve the desired final grain size has been developed. The presented research also deals, in a relatively detailed and comparative way, with the use of ultrasound. In this context, a very close correlation between the process functions of extrusion and the speed of longitudinal ultrasonic waves was confirmed.

ACS Style

Marta Harničárová; Jan Valíček; Milena Kušnerová; Zuzana Palková; Ivan Kopal; Cristina Borzan; Milan Kadnár; Stanislav Paulovič. A New Method of Predicting the Structural and Mechanical Change of Materials during Extrusion by the Method of Multiple Plastic Deformations. Materials 2021, 14, 2594 .

AMA Style

Marta Harničárová, Jan Valíček, Milena Kušnerová, Zuzana Palková, Ivan Kopal, Cristina Borzan, Milan Kadnár, Stanislav Paulovič. A New Method of Predicting the Structural and Mechanical Change of Materials during Extrusion by the Method of Multiple Plastic Deformations. Materials. 2021; 14 (10):2594.

Chicago/Turabian Style

Marta Harničárová; Jan Valíček; Milena Kušnerová; Zuzana Palková; Ivan Kopal; Cristina Borzan; Milan Kadnár; Stanislav Paulovič. 2021. "A New Method of Predicting the Structural and Mechanical Change of Materials during Extrusion by the Method of Multiple Plastic Deformations." Materials 14, no. 10: 2594.

Journal article
Published: 10 May 2021 in Energies
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The article presents the problems of diagnostics of low-power solar power plants with the use of the three-valued (3VL) state assessment {2, 1, 0}. The 3VL diagnostics is developed on the basis of two-valued diagnostics (2VL), and it is elaborated on. In the (3VL) diagnostics, the range of changes in the values of the signals from the 2VL logic was accepted for the serviceability condition: state {12VL}. This range of signal value changes for logic (3VL) was divided into two signal value change sub-ranges, which were assigned two status values in the logic (3VL): {23VL}—serviceability condition and {13VL}—incomplete serviceability condition. The state of failure for both logics applied of the valence of states is interpreted equally for the same changes in the values of diagnostic signals, the possible changes of which exceed the ranges of their permissible changes. The DIAG 2 intelligent system based on an artificial neural network was used in diagnostic tests. For this purpose, the article presents the structure, algorithm and rules of inference used in the DIAG intelligent diagnostic system. The diagnostic method used in the DIAG 2 system utilizes the method known from the literature to compare diagnostic signal vectors with the reference signal vectors assigned. The result of this vector analysis is the metric developed of the difference vector. The problem of signal analysis and comparison is carried out in the input cells of the neural network. In the output cells of the neural network, in turn, the classification of the states of the object’s elements is realized. Depending on the condition of the individual elements that make up the object, the method is able to indicate whether the elements are in working order, out of order or require quick repair/replacement.

ACS Style

Stanisław Duer; Jan Valicek; Jacek Paś; Marek Stawowy; Dariusz Bernatowicz; Radosław Duer; Marcin Walczak. Neural Networks in the Diagnostics Process of Low-Power Solar Plant Devices. Energies 2021, 14, 2719 .

AMA Style

Stanisław Duer, Jan Valicek, Jacek Paś, Marek Stawowy, Dariusz Bernatowicz, Radosław Duer, Marcin Walczak. Neural Networks in the Diagnostics Process of Low-Power Solar Plant Devices. Energies. 2021; 14 (9):2719.

Chicago/Turabian Style

Stanisław Duer; Jan Valicek; Jacek Paś; Marek Stawowy; Dariusz Bernatowicz; Radosław Duer; Marcin Walczak. 2021. "Neural Networks in the Diagnostics Process of Low-Power Solar Plant Devices." Energies 14, no. 9: 2719.

Journal article
Published: 25 November 2020 in Materials
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The objective of this paper is to present a new way of identifying and predicting the relationship between thermodynamic and physical-mechanical parameters in the formation of a layer after spraying on a substrate with NiCrBSi alloy and its subsequent processing by milling. The milling of the spherical surface of the EN 10060 material after spraying was performed on the DMU 40 eVolinear linear milling centre. The experimental part of the article is focused on investigating the influence of cutting parameters when machining a selected combination of materials (substrate-coating: EN 10060 steel-NiCrBSi alloy). The experiment is based on the results of direct measurements of three basic cutting parameters, namely: cutting speed vc (m∙min−1), feed per tooth fz (mm), and the depth of cut ap(mm). The new distribution functions of selected cutting parameters were derived. The analytical results of the thermodynamic calculations performed on nickel-based alloy can be used for accurate predictions of the technological parameters of milling a spherical substrate made of EN 10060 steel after HVOF spraying, and also for both sample preparation and the subsequent production of high-quality coatings.

ACS Style

Jan Valíček; Marta Harničárová; Jan Řehoř; Milena Kušnerová; Ludmila Kučerová; Miroslav Gombár; Jaroslava Fulemová; Jan Filipenský; Jan Hnátík. Thermodynamics and Mechanics of Thermal Spraying of Steel EN 10060 Substrate with NiCrBSi Alloy after Milling. Materials 2020, 13, 5344 .

AMA Style

Jan Valíček, Marta Harničárová, Jan Řehoř, Milena Kušnerová, Ludmila Kučerová, Miroslav Gombár, Jaroslava Fulemová, Jan Filipenský, Jan Hnátík. Thermodynamics and Mechanics of Thermal Spraying of Steel EN 10060 Substrate with NiCrBSi Alloy after Milling. Materials. 2020; 13 (23):5344.

Chicago/Turabian Style

Jan Valíček; Marta Harničárová; Jan Řehoř; Milena Kušnerová; Ludmila Kučerová; Miroslav Gombár; Jaroslava Fulemová; Jan Filipenský; Jan Hnátík. 2020. "Thermodynamics and Mechanics of Thermal Spraying of Steel EN 10060 Substrate with NiCrBSi Alloy after Milling." Materials 13, no. 23: 5344.

Journal article
Published: 11 November 2020 in Polymers
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Modelling the influence of high-energy ionising radiation on the properties of materials with polymeric matrix using advanced artificial intelligence tools plays an important role in the research and development of new materials for various industrial applications. It also applies to effective modification of existing materials based on polymer matrices to achieve the desired properties. In the presented work, the effects of high-energy electron beam radiation with various doses on the dynamic mechanical properties of melamine resin, phenol-formaldehyde resin, and nitrile rubber blend have been studied over a wide temperature range. A new stiffness-temperature model based on Weibull statistics of the secondary bonds breaking during the relaxation transitions has been developed to quantitatively describe changes in the storage modulus with temperature and applied radiation dose until the onset of the temperature of the additional, thermally-induced polymerisation reactions. A global search real-coded genetic algorithm has been successfully applied to optimise the parameters of the developed model by minimising the sum-squared error. An excellent agreement between the modelled and experimental data has been found.

ACS Style

Ivan Kopal; Juliána Vršková; Alžbeta Bakošová; Marta Harničárová; Ivan Labaj; Darina Ondrušová; Jan Valíček; Jan Krmela. Modelling the Stiffness-Temperature Dependence of Resin-Rubber Blends Cured by High-Energy Electron Beam Radiation Using Global Search Genetic Algorithm. Polymers 2020, 12, 2652 .

AMA Style

Ivan Kopal, Juliána Vršková, Alžbeta Bakošová, Marta Harničárová, Ivan Labaj, Darina Ondrušová, Jan Valíček, Jan Krmela. Modelling the Stiffness-Temperature Dependence of Resin-Rubber Blends Cured by High-Energy Electron Beam Radiation Using Global Search Genetic Algorithm. Polymers. 2020; 12 (11):2652.

Chicago/Turabian Style

Ivan Kopal; Juliána Vršková; Alžbeta Bakošová; Marta Harničárová; Ivan Labaj; Darina Ondrušová; Jan Valíček; Jan Krmela. 2020. "Modelling the Stiffness-Temperature Dependence of Resin-Rubber Blends Cured by High-Energy Electron Beam Radiation Using Global Search Genetic Algorithm." Polymers 12, no. 11: 2652.

Journal article
Published: 30 July 2020 in Coatings
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The high-velocity oxy-fuel spraying process was used to investigate and improve the surface properties of a workpiece. The research was focused on the spherical surface of a workpiece made of high-strength steel, a ball and socket assembly. After spraying with a nickel alloy, the surface was machined by milling. The coating was carried out as a process in which a very thin layer of coating of the required thickness and the required specific properties, i.e., high Vickers hardness, adhesion to the surface, wear resistance and other important characteristics, which must be respected in other machining methods, was applied to the already finished, heat-prepared metal substrate. This article deals with the milling of complex surfaces of steel substrate EN 10060 after spraying with NiCrBSi alloy. After spraying, a total of 15 milling experiments were performed in order to determine precisely the optimal cutting parameters of milling and surface adhesion, based on newly acquired prediction relations. The main presented results are new relations for the determination of optimal technological milling conditions based on the identification of adhesive sections using derived equations. The new relations were verified and also compared with the current literature in the field.

ACS Style

Jan Valíček; Marta Harničárová; Jan Řehoř; Milena Kušnerová; Jaroslava Fulemová; Miroslav Gombár; Ludmila Kučerová; Jan Filipenský; Jan Hnátík. Milling of Complex Surfaces of EN 10060 Steel after HVOF Sprayed NiCrBSi Coatings. Coatings 2020, 10, 744 .

AMA Style

Jan Valíček, Marta Harničárová, Jan Řehoř, Milena Kušnerová, Jaroslava Fulemová, Miroslav Gombár, Ludmila Kučerová, Jan Filipenský, Jan Hnátík. Milling of Complex Surfaces of EN 10060 Steel after HVOF Sprayed NiCrBSi Coatings. Coatings. 2020; 10 (8):744.

Chicago/Turabian Style

Jan Valíček; Marta Harničárová; Jan Řehoř; Milena Kušnerová; Jaroslava Fulemová; Miroslav Gombár; Ludmila Kučerová; Jan Filipenský; Jan Hnátík. 2020. "Milling of Complex Surfaces of EN 10060 Steel after HVOF Sprayed NiCrBSi Coatings." Coatings 10, no. 8: 744.

Journal article
Published: 23 May 2020 in International Journal of Environmental Research and Public Health
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Iron is an essential trace element, but at high doses, this element may pose a health risk. Wastewater from iron ore mining, steel production, and metal processing, among other heavy metals, also contains high concentrations of iron (Fe3+). The use of sorption on natural materials is a potential alternative to conventional methods for removing iron ions, also because of low cost. The methods presented in this article are based on the study of kinetic properties and the acquisition of adsorption isotherms, which are one of the most important characteristics of adsorption mechanisms. The course of sorption is analyzed according to the Freundlich sorption isotherm model. Isotherm parameters are evaluated using experimental results of ferric cation sorption. The results presented relate to the investigation of natural zeolite-clinoptilolite as a ferric cation sorbent, providing a measurement of the sorption kinetics as well as the observed sorption parameters of iron cations from aqueous media. The optimal time for equilibrium in the adsorption system is determined from the kinetic dependencies. The dependence of the achieved equilibrium concentration on the initial concentration of the solution was also expressed, both graphically and analytically. The new prediction model was compared with the traditional Freundlich model. Finally, adsorption isotherms tested under laboratory conditions for a practical application can be recommended for the preliminary examination of the possible technological use of natural zeolite in the wastewater treatment process.

ACS Style

Iveta Pandová; Miroslav Rimár; Anton Panda; Jan Valíček; Milena Kušnerová; Marta Harničárová. A Study of Using Natural Sorbent to Reduce Iron Cations from Aqueous Solutions. International Journal of Environmental Research and Public Health 2020, 17, 3686 .

AMA Style

Iveta Pandová, Miroslav Rimár, Anton Panda, Jan Valíček, Milena Kušnerová, Marta Harničárová. A Study of Using Natural Sorbent to Reduce Iron Cations from Aqueous Solutions. International Journal of Environmental Research and Public Health. 2020; 17 (10):3686.

Chicago/Turabian Style

Iveta Pandová; Miroslav Rimár; Anton Panda; Jan Valíček; Milena Kušnerová; Marta Harničárová. 2020. "A Study of Using Natural Sorbent to Reduce Iron Cations from Aqueous Solutions." International Journal of Environmental Research and Public Health 17, no. 10: 3686.

Journal article
Published: 06 April 2020 in Applied Sciences
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In this research, the authors set out to propose a new method of predicting and adjusting the main cutting parameters of chip machining, namely spraying on the substrate. In the experiments, a total of 28 turning cuts on a Stellite 6 coating layer were realized. The base materials of the Stellite 6 layers were EN S235JRG1 and carbide WC-Co. This work aimed to find out and optimize the influence of different combinations of cutting parameters. Due to the coating solution, the work is focused on the evaluation of the roughness Ra (μm) of the turned substrate, the grain size Dgr (μm) of the spraying, the normal stress σrz (MPa), the residual stress σrez (MPa), the specific cutting force Fc (N), the quality of adhesion to the substrate Adhmp (MPa) and other parameters. For the sake of a comprehensive solution to the problem, several new predictive equations and subsequent suggestions for solutions have been derived from this research topic based on the newly obtained experimental results. The proposed models and procedures make it possible to get new results and insights into coating technologies.

ACS Style

Jan Valíček; Marta Harničárová; Jan Řehoř; Milena Kušnerová; Miroslav Gombár; Mário Drbúl; Michal Šajgalík; Jan Filipenský; Jaroslava Fulemová; Alena Vagaská. Prediction of Cutting Parameters of HVOF-Sprayed Stellite 6. Applied Sciences 2020, 10, 2524 .

AMA Style

Jan Valíček, Marta Harničárová, Jan Řehoř, Milena Kušnerová, Miroslav Gombár, Mário Drbúl, Michal Šajgalík, Jan Filipenský, Jaroslava Fulemová, Alena Vagaská. Prediction of Cutting Parameters of HVOF-Sprayed Stellite 6. Applied Sciences. 2020; 10 (7):2524.

Chicago/Turabian Style

Jan Valíček; Marta Harničárová; Jan Řehoř; Milena Kušnerová; Miroslav Gombár; Mário Drbúl; Michal Šajgalík; Jan Filipenský; Jaroslava Fulemová; Alena Vagaská. 2020. "Prediction of Cutting Parameters of HVOF-Sprayed Stellite 6." Applied Sciences 10, no. 7: 2524.

Journal article
Published: 05 March 2020 in Applied Sciences
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One of the progressive machining methods for machining of exotic alloys is trochoidal milling. The main contribution of this paper is the analysis of basic parameters of trochoidal movement for the prediction of their impacts on the machining force. Knowledge of these predictions will make it possible to decide more effectively, on the selection of trochoidal parameters. Results from not only this paper, but our whole research on trochoidal milling are applied in various companies located near the city of the University of Zilina, such as IGV Technologies and LAGO instruments, but also local factories of well-known companies Volkswagen Slovakia, Schaeffler Kysuce, etc.

ACS Style

Michal Šajgalík; Milena Kušnerová; Marta Harničárová; Jan Valíček; Andrej Czán; Tatiana Czánová; Mário Drbúl; Marian Borzan; Ján Kmec. Analysis and Prediction of the Machining Force Depending on the Parameters of Trochoidal Milling of Hardened Steel. Applied Sciences 2020, 10, 1788 .

AMA Style

Michal Šajgalík, Milena Kušnerová, Marta Harničárová, Jan Valíček, Andrej Czán, Tatiana Czánová, Mário Drbúl, Marian Borzan, Ján Kmec. Analysis and Prediction of the Machining Force Depending on the Parameters of Trochoidal Milling of Hardened Steel. Applied Sciences. 2020; 10 (5):1788.

Chicago/Turabian Style

Michal Šajgalík; Milena Kušnerová; Marta Harničárová; Jan Valíček; Andrej Czán; Tatiana Czánová; Mário Drbúl; Marian Borzan; Ján Kmec. 2020. "Analysis and Prediction of the Machining Force Depending on the Parameters of Trochoidal Milling of Hardened Steel." Applied Sciences 10, no. 5: 1788.

Journal article
Published: 01 March 2020 in Mathematics
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The study of the combination of chemical kinetics with transport phenomena is the main step for reactor design. It is possible to deviate from the model behaviour, the cause of which may be fluid channelling, fluid recirculation, or creation of stagnant regions in the vessel, by using a dispersion model. In this paper, the known general solution of the dispersion model for closed vessels is given in a new, straightforward form. In order to improve the classical theoretical solution, a hybrid of analytical and numerical methods is used. It is based on the general analytic solution and the least-squares method by fitting the results of a tracer test carried out on the vessel with the values of the analytic solution. Thus, the accuracy of the estimation for the vessel dispersion number is increased. The presented method can be used to similar problems modelled by a partial differential equation and some boundary conditions which are not sufficient to ensure the uniqueness of the solution.

ACS Style

Alexandru-Nicolae Dimache; Ghiocel Groza; Marilena Jianu; Sorin Perju; Laurențiu Rece; Marta Harničárová; Jan Valíček. Optimization of the Solution of a Dispersion Model. Mathematics 2020, 8, 318 .

AMA Style

Alexandru-Nicolae Dimache, Ghiocel Groza, Marilena Jianu, Sorin Perju, Laurențiu Rece, Marta Harničárová, Jan Valíček. Optimization of the Solution of a Dispersion Model. Mathematics. 2020; 8 (3):318.

Chicago/Turabian Style

Alexandru-Nicolae Dimache; Ghiocel Groza; Marilena Jianu; Sorin Perju; Laurențiu Rece; Marta Harničárová; Jan Valíček. 2020. "Optimization of the Solution of a Dispersion Model." Mathematics 8, no. 3: 318.

Journal article
Published: 02 January 2020 in International Journal of Environmental Research and Public Health
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The paper presents the results of the development of the cardio-forecasting technology, which introduces a new method to monitor the state of human-operator, which is characteristic for the given production conditions and for individual operators, to predict the moment of exhaustion of his/her working capacity. The work aims to demonstrate the unique, distinctive features of the cardio-forecasting technology for predicting an individual limit of his/her working capacity for each person. A unique methodology for predicting individually for each person the moment when he/she reaches the limit of his/her working capacity is based on a spectral analysis of a human phonocardiogram in order to isolate the frequency component located at the heart contraction frequency. The trend of the amplitude of this component is approximated by its model; consequently, the coefficients of the trend model are determined. They include the operator’s operating time until his/her working capacity is exhausted. A methodology for predicting the moment when he/she reaches the limit of his/her working capacity for each person individually and assessment based on this degree of criticality of their condition will be realized as a software application for smartphones using the Android operating system.

ACS Style

Anton Panda; Volodymyr Nahornyi; Jan Valíček; Marta Harničárová; Iveta Pandová; Cristina Borzan; Samuel Cehelský; Lukáš Androvič; Hakan Tozan; Milena Kušnerová. Application of Cardio-Forecasting for Evaluation of Human—Operator Performance. International Journal of Environmental Research and Public Health 2020, 17, 326 .

AMA Style

Anton Panda, Volodymyr Nahornyi, Jan Valíček, Marta Harničárová, Iveta Pandová, Cristina Borzan, Samuel Cehelský, Lukáš Androvič, Hakan Tozan, Milena Kušnerová. Application of Cardio-Forecasting for Evaluation of Human—Operator Performance. International Journal of Environmental Research and Public Health. 2020; 17 (1):326.

Chicago/Turabian Style

Anton Panda; Volodymyr Nahornyi; Jan Valíček; Marta Harničárová; Iveta Pandová; Cristina Borzan; Samuel Cehelský; Lukáš Androvič; Hakan Tozan; Milena Kušnerová. 2020. "Application of Cardio-Forecasting for Evaluation of Human—Operator Performance." International Journal of Environmental Research and Public Health 17, no. 1: 326.

Journal article
Published: 02 January 2020 in Mathematics
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This article intends to define a new methodology that allows the processing of complex surfaces in space through processing cycles, in parallel superposed planes—the variant known as generic processing in 2 ½ D—but with predictable control over the deviation from the geometric form of the surface to be processed. The novel methodology consists of identifying the optimal distances between the working planes and the corresponding successive positions so that the deviations from the resulting geometric form fall within the prescribed limits. It is also envisaged that the method will provide facilities in terms of the possibilities for evaluation of deviations from the given form of the surface, and keeping them under control by the stage of elaboration of the numerical control programs. The new optimization is designed to determine the maximum distances between successive processing planes and their position in space, depending on the spatial shape of the surface to be processed. Thus, the aim is to obtain a small number of processing planes with a favorable effect on productivity, but under conditions that respect the tolerances of the surface or the profile, a restriction that otherwise has a negative effect on the same process.

ACS Style

Laurentiu Rece; Virgil Florescu; Arina Modrea; Victor Jeflea; Marta Harničárová; Jan Valíček; Marian Borzan. Optimization of the 2 ½ D Processing Method of Complex Parts, through a Predictive Algorithm for Controlling the Geometric Shape Deviations Resulting from Processing. Mathematics 2020, 8, 59 .

AMA Style

Laurentiu Rece, Virgil Florescu, Arina Modrea, Victor Jeflea, Marta Harničárová, Jan Valíček, Marian Borzan. Optimization of the 2 ½ D Processing Method of Complex Parts, through a Predictive Algorithm for Controlling the Geometric Shape Deviations Resulting from Processing. Mathematics. 2020; 8 (1):59.

Chicago/Turabian Style

Laurentiu Rece; Virgil Florescu; Arina Modrea; Victor Jeflea; Marta Harničárová; Jan Valíček; Marian Borzan. 2020. "Optimization of the 2 ½ D Processing Method of Complex Parts, through a Predictive Algorithm for Controlling the Geometric Shape Deviations Resulting from Processing." Mathematics 8, no. 1: 59.

Journal article
Published: 10 August 2019 in Materials
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The aim of the paper was to examine the influence of cutting conditions on the roughness of surfaces machined by longitudinal turning, namely of surfaces coated with Stellite 6 prepared by high-velocity oxygen fuel (HVOF) technology and applied onto a standard structural steel substrate. From the results of measurements of the cutting parameters, a prediction model of the roughness parameters was created using mathematical and statistical methods. Based on a more detailed analysis and data comparison, a new method for prediction of parameters of longitudinal turning technology was obtained. The main aim of the paper was to identify the mutual discrete relationships between the substrate roughness and the machining parameters. These were the feed rate vc (m·min−1), in the case of turning and milling, and the feed rate f (mm·rev−1) and the depth of cut ap (mm). The paper compared and verified two approaches of this method, namely the mathematical statistical approach, the analytical approach and measured dates. From the evaluated and interpreted results, new equations were formulated, enabling prediction of the material parameters of the workpiece, the technological parameters and the parameters of surface quality.

ACS Style

Jan Valíček; Jan Rehor; Marta Harničárová; Miroslav Gombár; Milena Kušnerová; Jaroslava Fulemová; Alena Vagaská. Investigation of Surface Roughness and Predictive Modelling of Machining Stellite 6. Materials 2019, 12, 2551 .

AMA Style

Jan Valíček, Jan Rehor, Marta Harničárová, Miroslav Gombár, Milena Kušnerová, Jaroslava Fulemová, Alena Vagaská. Investigation of Surface Roughness and Predictive Modelling of Machining Stellite 6. Materials. 2019; 12 (16):2551.

Chicago/Turabian Style

Jan Valíček; Jan Rehor; Marta Harničárová; Miroslav Gombár; Milena Kušnerová; Jaroslava Fulemová; Alena Vagaská. 2019. "Investigation of Surface Roughness and Predictive Modelling of Machining Stellite 6." Materials 12, no. 16: 2551.

Journal article
Published: 21 June 2019 in Polymers
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The presented work deals with the creation of a new radial basis function artificial neural network-based model of dynamic thermo-mechanical response and damping behavior of thermoplastic elastomers in the whole temperature interval of their entire lifetime and a wide frequency range of dynamic mechanical loading. The created model is based on experimental results of dynamic mechanical analysis of the widely used thermoplastic polyurethane, which is one of the typical representatives of thermoplastic elastomers. Verification and testing of the well-trained radial basis function neural network for temperature and frequency dependence of dynamic storage modulus, loss modulus, as well as loss tangent prediction showed excellent correspondence between experimental and modeled data, including all relaxation events observed in the polymeric material under study throughout the monitored temperature and frequency interval. The radial basis function artificial neural network has been confirmed to be an exceptionally high-performance artificial intelligence tool of soft computing for the effective predicting of short-term viscoelastic behavior of thermoplastic elastomer systems based on experimental results of dynamic mechanical analysis.

ACS Style

Ivan Kopal; Marta Harničárová; Jan Valíček; Jan Krmela; Ondrej Lukáč. Radial Basis Function Neural Network-Based Modeling of the Dynamic Thermo-Mechanical Response and Damping Behavior of Thermoplastic Elastomer Systems. Polymers 2019, 11, 1074 .

AMA Style

Ivan Kopal, Marta Harničárová, Jan Valíček, Jan Krmela, Ondrej Lukáč. Radial Basis Function Neural Network-Based Modeling of the Dynamic Thermo-Mechanical Response and Damping Behavior of Thermoplastic Elastomer Systems. Polymers. 2019; 11 (6):1074.

Chicago/Turabian Style

Ivan Kopal; Marta Harničárová; Jan Valíček; Jan Krmela; Ondrej Lukáč. 2019. "Radial Basis Function Neural Network-Based Modeling of the Dynamic Thermo-Mechanical Response and Damping Behavior of Thermoplastic Elastomer Systems." Polymers 11, no. 6: 1074.

Journal article
Published: 07 March 2019 in International Journal of Mechanical Sciences
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Residual stresses are the result of distortion of the equilibrium forces on the surface of the material, which leads to its deformation and distribution of unevenness of the machined surfaces. The paper presents a new approach for the prediction of residual stress distribution after milling. This method for solving residual stress and predictions is highly dependent on material properties and therefore provides substantial improvement and modelling of the transformation states of the material that is necessary to reliably predict its behaviour under the conditions of the functional load. It has been found that roughness and roughness control determine the intensity of residual stress. Samples made of hardened steel X37CrMoV5-1 were used as the experimental material. A Proto iXRD diffractometer was used for residual stress measurement. The validity of the proposed method is confirmed by the good agreements between the theoretical, experimental results and results obtained from a literature survey.

ACS Style

Jan Valíček; Andrej Czán; Marta Harničárová; Michal Šajgalík; Milena Kušnerová; Tatiana Czánová; Ivan Kopal; Miroslav Gombár; Ján Kmec; Marek Šafář. A new way of identifying, predicting and regulating residual stress after chip-forming machining. International Journal of Mechanical Sciences 2019, 155, 343 -359.

AMA Style

Jan Valíček, Andrej Czán, Marta Harničárová, Michal Šajgalík, Milena Kušnerová, Tatiana Czánová, Ivan Kopal, Miroslav Gombár, Ján Kmec, Marek Šafář. A new way of identifying, predicting and regulating residual stress after chip-forming machining. International Journal of Mechanical Sciences. 2019; 155 ():343-359.

Chicago/Turabian Style

Jan Valíček; Andrej Czán; Marta Harničárová; Michal Šajgalík; Milena Kušnerová; Tatiana Czánová; Ivan Kopal; Miroslav Gombár; Ján Kmec; Marek Šafář. 2019. "A new way of identifying, predicting and regulating residual stress after chip-forming machining." International Journal of Mechanical Sciences 155, no. : 343-359.

Journal article
Published: 18 January 2019 in Coatings
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The current practice in the field of anodic oxidation of aluminium and its alloys is based mainly on a set of partial empirical experiences of technologists obtained during surface treatment. The aim of the presented paper is deeper and more complex identification of the influence of chemical and technological factors acting during the anodic oxidation process especially on the thickness of the formed surface layer by the electrolysis method in a sulfuric acid solution. The current density was selected as the basic criterion for verification evaluation and analysis of experimentally obtained data, in accordance with Faraday’s laws. For current densities of 1 to 5 A·dm−2, the synergy of significant influence factors was identified, and mathematical and statistical models were then developed to predict the thickness of the surface layer with a relative accuracy of up to 10%. The presented paper does not only focus on the observation of the thickness of the surface layer desired by the customer, but also on the monitoring of this thickness in relation to the overall layer thickness of the coating.

ACS Style

Miroslav Gombár; Alena Vagaská; Marta Harničárová; Jan Valíček; Milena Kušnerová; Andrej Czán; Ján Kmec. Experimental Analysis of the Influence of Factors Acting on the Layer Thickness Formed by Anodic Oxidation of Aluminium. Coatings 2019, 9, 57 .

AMA Style

Miroslav Gombár, Alena Vagaská, Marta Harničárová, Jan Valíček, Milena Kušnerová, Andrej Czán, Ján Kmec. Experimental Analysis of the Influence of Factors Acting on the Layer Thickness Formed by Anodic Oxidation of Aluminium. Coatings. 2019; 9 (1):57.

Chicago/Turabian Style

Miroslav Gombár; Alena Vagaská; Marta Harničárová; Jan Valíček; Milena Kušnerová; Andrej Czán; Ján Kmec. 2019. "Experimental Analysis of the Influence of Factors Acting on the Layer Thickness Formed by Anodic Oxidation of Aluminium." Coatings 9, no. 1: 57.

Journal article
Published: 01 January 2019 in Defect and Diffusion Forum
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Thermal characteristic of insulation concretes is one of the key components in materials selection especially in civil constructions. In this article, non–tabulated material parameters of some innovative highly-insulating non-structural concretes are presented. The specific volumetric heat capacity, specific heat capacity, parameter of temperature diffusivity and thermal mass parameter of the innovative highly-insulating cementitious composites were determined. The experiments were conducted using a prototype automated calorimetric chamber. The measurement results are compared with those obtained by using a commercial multifunctional instrument (Isomet 2114) and are accompanied by the measurement of other significant thermal parameters of the cementitious composites under investigation. The results indicated that there is potential of using the newly created types of concrete for insulation purposes.

ACS Style

Milena Kušnerová; Marta Harničárová; Jan Valíček; Zuzana Palková; Zdenko Tkáč; Anton Panda; Jan Kmec; Ondrej Lukáč. Measurement of the Thermal Properties of Innovative Highly-Insulating Non-Structural Concretes. Defect and Diffusion Forum 2019, 390, 41 -52.

AMA Style

Milena Kušnerová, Marta Harničárová, Jan Valíček, Zuzana Palková, Zdenko Tkáč, Anton Panda, Jan Kmec, Ondrej Lukáč. Measurement of the Thermal Properties of Innovative Highly-Insulating Non-Structural Concretes. Defect and Diffusion Forum. 2019; 390 ():41-52.

Chicago/Turabian Style

Milena Kušnerová; Marta Harničárová; Jan Valíček; Zuzana Palková; Zdenko Tkáč; Anton Panda; Jan Kmec; Ondrej Lukáč. 2019. "Measurement of the Thermal Properties of Innovative Highly-Insulating Non-Structural Concretes." Defect and Diffusion Forum 390, no. : 41-52.

Journal article
Published: 28 November 2018 in Materials
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Irradiation by ionizing radiation is a specific type of controllable modification of the physical and chemical properties of a wide range of polymers, which is, in comparison to traditional chemical methods, rapid, non-polluting, simple, and relatively cheap. In the presented paper, the influence of high-energy ionizing radiation on the basic mechanical properties of the melamine resin, phenol-formaldehyde resin, and nitrile rubber blend has been studied for the first time. The mechanical properties of irradiated samples were compared to those of non-irradiated materials. It was found that radiation doses up to 150 kGy improved the mechanical properties of the tested materials in terms of a significant increase in stress at break, tensile strength, and tensile modulus at 40% strain, while decreasing the value of strain at break. At radiation doses above 150 kGy, the irradiated polymer blend is already degrading, and its tensile characteristics significantly deteriorate. An radiation dose of 150 kGy thus appears to be optimal from the viewpoint of achieving significant improvement, and the radiation treatment of the given polymeric blend by a beam of accelerated electrons is a very promising alternative to the traditional chemical mode of treatment which impacts the environment.

ACS Style

Ivan Kopal; Juliana Vršková; Ivan Labaj; Darina Ondrušová; Peter Hybler; Marta Harničárová; Jan Valíček; Milena Kušnerová. The Effect of High-Energy Ionizing Radiation on the Mechanical Properties of a Melamine Resin, Phenol-Formaldehyde Resin, and Nitrile Rubber Blend. Materials 2018, 11, 2405 .

AMA Style

Ivan Kopal, Juliana Vršková, Ivan Labaj, Darina Ondrušová, Peter Hybler, Marta Harničárová, Jan Valíček, Milena Kušnerová. The Effect of High-Energy Ionizing Radiation on the Mechanical Properties of a Melamine Resin, Phenol-Formaldehyde Resin, and Nitrile Rubber Blend. Materials. 2018; 11 (12):2405.

Chicago/Turabian Style

Ivan Kopal; Juliana Vršková; Ivan Labaj; Darina Ondrušová; Peter Hybler; Marta Harničárová; Jan Valíček; Milena Kušnerová. 2018. "The Effect of High-Energy Ionizing Radiation on the Mechanical Properties of a Melamine Resin, Phenol-Formaldehyde Resin, and Nitrile Rubber Blend." Materials 11, no. 12: 2405.

Journal article
Published: 09 June 2018 in Polymers
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The precise experimental estimation of mechanical properties of rubber blends can be a very costly and time-consuming process. The present work explores the possibilities of increasing its efficiency by using artificial neural networks to study the mechanical behavior of these widely used materials. A multilayer feed-forward back-propagation artificial neural network model, with a strain and the carbon black content as input parameters and stress as an output parameter, has been developed to predict the uniaxial tensile response of vulcanized natural rubber blends with different contents of carbon black in the form of engineering stress-strain curves. A novel procedure has been created for the simulation of the optimized artificial neural network model with input datasets generated by a regression model of an experimental dependence of tensile strain-at-break on the carbon black content in the investigated blends. Errors of the prediction of experimental stress-strain curves, as well as of tensile strain-at-break, tensile stress-at-break and M100 tensile modulus were estimated for all simulated stress-strain curves. The present study demonstrated that the performance of a developed neural network model to predict the stress-strain curves of rubber blends with different contents of carbon black is also exceptionally high in the case of a network that had never learned the input data, which makes it a suitable tool for extensive use in practice.

ACS Style

Ivan Kopal; Ivan Labaj; Marta Harnicarova; Jan Valíček; Dušan Hrubý. Prediction of the Tensile Response of Carbon Black Filled Rubber Blends by Artificial Neural Network. Polymers 2018, 10, 644 .

AMA Style

Ivan Kopal, Ivan Labaj, Marta Harnicarova, Jan Valíček, Dušan Hrubý. Prediction of the Tensile Response of Carbon Black Filled Rubber Blends by Artificial Neural Network. Polymers. 2018; 10 (6):644.

Chicago/Turabian Style

Ivan Kopal; Ivan Labaj; Marta Harnicarova; Jan Valíček; Dušan Hrubý. 2018. "Prediction of the Tensile Response of Carbon Black Filled Rubber Blends by Artificial Neural Network." Polymers 10, no. 6: 644.