Tomas Bata University in Zlín
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Chitosan modified by kombucha-derived bacterial cellulose: Rheological behavior and properties of convened biopolymer films
Get PDFThis work investigates the rheological behavior and characteristics of solutions and convened biopolymer films from Chitosan (Chi) modified by kombucha-derived bacterial cellulose (KBC). The Arrhenius equation and the Ostwald de Waele model (power-law) revealed that the Chi/KBC solutions exhibited non-Newtonian behavior. Both temperature and KBC concentration strongly affected their solution viscosity. With the selection of a proper solvent for chitosan solubilization, it may be possible to improve the performances of chitosan films for specific applications. The elasticity of the prepared films containing KBC 10% w/w was preferable when compared to the controls. FTIR analysis has confirmed the presence of bacterial cellulose, chitosan acetate, and chitosan lactate as the corresponding components in the produced biopolymer films. The thermal behaviors of the Chi (lactic acid)/KBC samples showed slightly higher stability than Chi (acetic acid)/KBC. Generally, these results will be helpful in the preparation processes of the solutions and biopolymer films of Chi dissolved in acetic or lactic acid modified by KBC powder to fabricate food packaging, scaffolds, and bioprinting inks, or products related to injection or direct extrusion through a needle.FRC/2022/2102, RP/CPS/2022/005; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Univerzita Tomáše Bati ve Zlíně: IGA/CPS/2022/002Ministry of Education, Youth and Sports of the Czech Republic [DKRVO RP/CPS/2022/005, FRC/2022/2102]; Tomas Bata University [IGA/CPS/2022/002
Digital transformation of strategic management of SMEs in the Czech Republic
No full textStrategic management of SMEs is perceived as crucial backbone of their business, as it impacts their business models and internal processes all the way up to digital innovation measured by the level of digital maturity. How do the strategic management factors influence the digital maturity? Through quantitative analysis of 76 questionnaires collected from SMEs in the Czech Republic, the research data was collected and statistically tested. Results imply that strategic management factors affect the level of digital maturity. This paper contributes to prior literature by practical implementation of modified digital maturity model and by addressing the correlation of strategic management factors and the level of digital maturity. Limitations springing from sample’s site and environment are addressed and discussion on the results is conducted. Author proposes a conclusion that strategic management factors can be perceived as a driver of digital transformation, emphasizing the need for future research and practical discussion.Tomas Bata University in Zlin, TB
Water policy and legislative responses to climate change in the Czech Republic
Get PDFThe recurring floods and droughts in the Czech Republic show that climate change requires far-reaching changes in water management. We analyse the responses already reflected in Czech water policy and legislation at three levels: strategic, statutory and constitutional. We first describe the substantial changes that have been satisfactorily introduced into the Czech government's policies. We then trace the far less successful developments in the law, which have so far essentially been limited to drought plans and restrictions on water extraction during droughts. At the core, we concentrate on the political attempts to constitutionalize water protection.Czech Academy of Sciences; Lumina quaeruntur award of the Czech Academy of Science
Self-regulation of learning in the context of modern technology: a review of empirical studies
Get PDFPurpose: Self-regulation is the level of learning where the learner becomes an active agent in their learning process in terms of activity and aspects of motivation and metacognition. The current paper mostly deals with the metacognitive aspect. The purpose of this study is to gain insight into self-regulation of learning in the context of modern technology in higher education. This study also aims to highlight the direction, tendencies and trends toward which self-regulation of learning is moving in relation to modern technologies.
Design/methodology/approach: The review study was compiled via searches in three databases: Scopus, Web of Science and ERIC. A filter was used to search for empirical studies solely in English, published over the past decade on the topics of self-regulation of learning and technology in higher education.
Findings: The findings clearly show a correlation between self-regulation of learning and modern technology, especially after a significant event such as the Covid-19 pandemic. However, in the wake of this change, the field of education has seen the emergence of methods and new platforms that can provide support for the development of self-regulated learning strategies.
Originality/value: The originality of the study lies in the fact that it focuses on the link between self-regulation of learning and modern technologies in higher education, including some predictions of the future direction of self-regulation of learning in this context.Determinants of self-regulated learning of high school students at FHS TBU in Zlin [IGA/FHS/2022/001
Exploring the frequency of boundary control methods activation in metaheuristic algorithms
No full textRecently, Boundary Control Methods (BCMs) have become increasingly relevant in the field of metaheuristic algorithms. In this study, we investigate the relationship between the activation frequency of different BCMs and the problem’s dimensionality. Additionally, we analyze each problem dimension independently. Our research primarily concentrates on the top three algorithms from the IEEE CEC 2020 competition: AGSK, IMODE, and j2020, utilizing the competition benchmark set to conduct experiments. Our findings provide valuable insights into the metaheuristic domain, underlining the significance of comprehending BCM activation patterns to improve algorithm design and benchmarking practices.Faculty of Applied Informatics, Tomas Bata University in Zlin; Tomas Bata University in Zlin, TBU, (IGA/CebiaTech/2023/004)Internal Grant Agency of the Tomas Bata University in Zlin [IGA/CebiaTech/2023/004
Stabilization of second-order systems using PI controllers with delayed proportional and integral parts
No full textThe present paper deals with the stabilization, optimization, and control of second-order systems using a PI delayed controller. This study analyzes the control of linear-time invariant (LTI) systems with time delay in the integral and proportional parts of the PI delayed controller and obtains the region of global stability in the two-dimensional plane. The proposed stabilization method is verified through software simulations with two benchmark examples: the control of an inverted pendulum and the control of the stick-slip vibration. The results show the effectiveness and practical applicability of the proposed method in all analyses and control. Additionally, the optimization of LTI systems with time delay in the integral and proportional parts of the PI delayed controller is discussed, and selected heuristic methods are compared. Future research aims to implement modern optimization algorithms for solving non-smooth, non-convex, and non-Lipschitz optimization problems in this field.Grantová Agentura České Republiky, GA ČR, (GAČR 21-45465L
Regions of robust relative stability for PI controllers and LTI plants with unstructured multiplicative uncertainty: A second-order-based example
Get PDFThis example-oriented article addresses the computation of regions of all robustly relatively stabilizing Proportional-Integral (PI) controllers under various robust stability margins α for Linear Time-Invariant (LTI) plants with unstructured multiplicative uncertainty, where the plant model with multiplicative uncertainty is built on the basis of the second-order plant with three uncertain parameters. The applied graphical method, adopted from the authors’ previous work, is grounded in finding the contour that is linked to the pairs of P–I coefficients marginally fulfilling the condition of robust relative stability expressed using the H∞ norm. The illustrative example in the current article emphasizes that the technique itself for plotting the boundary contour of robust relative stability needs to be combined with the precondition of the nominally stable feedback control system and with the line for which the integral parameter equals zero in order to get the final robust relative stability regions. The calculations of the robust relative stability regions for various robust stability margins α are followed by the demonstration of the control behavior for two selected controllers applied to a set of members from the family of plants.College of Polytechnics Jihlava, (INT/2022/0002); Grantová Agentura České Republiky, GA ČR, (21–45465L)Czech Science Foundation (GACR) [21-45465L]; College of Polytechnics Jihlava [INT/2022/0002
Information system development for increased production process sustainability planning
Get PDFThe current era is characterized by rapid developing in all areas of society, but the most rapid expansion is in the field of science, knowledge, and technology. Galloping accessibility of the novel materials and technologies creates requirements of complex evaluation of their deployment to obtain economic and ecological sustainability. The authors of the paper present a proposal for a methodology enabling an effective decision-making process when choosing material and technological processes suitable for the manufacturing of products. This methodology was developed to enable the efficient evaluation of a wide range of materials, manufacturing technologies, including existing additive and hybrid and with focus on future and emerging technologies, too. The evaluation focuses on sustainability approach to minimize negative social and environmental impact while ensuring the required level of safety and profitability.Department of Production Engineering of Tomas Bata University in Zlin; Ministerstvo školstva, vedy, výskumu a športu Slovenskej republiky; Agentúra na Podporu Výskumu a Vývoja, APVV, (SK-CN-21-0046); Kultúrna a Edukacná Grantová Agentúra MŠVVaŠ SR, KEGA, (032TUKE-4/2022
A 3D visualization of Zlín in the eighteen–nineties using virtual reality
No full textThis paper describes a 3D interactive Virtual Reality application that visualizes the appearance of the town of Zlín in the Eighteen–nineties. The Blender software suite was used to create a complex 3D model of Zlín and its municipality in previous years. Next, the Unreal Engine software was used in order to create a desktop application. With the help of modern tools of this engine, the 3D environment of the model was modified to achieve greater realism. Now this application was upgraded so that a Virtual Reality output could be created. Such modifications were made to take advantage of as many benefits as possible that virtual reality offers. For the purposes of this visualization, the Oculus Quest device was used.Faculty of Applied Informatics, Tomas Bata University, (RVO/FAI/2021/002
Side charge propagation in simultaneous KPFM and transport measurement of humidity exposed graphene FET sensor
No full textThe surface diffusion (dissipation) of charge carriers enhanced by water molecules in solution-based biosensors and ambient operating gas sensors strongly influence their resistance response, sensitivity, and stability in time. Therefore, the information on the charge distribution at interfaces of conductive and insulating parts is essential for the operating sensors. This work presents the simultaneous measurement of the longitudinal macroscopic resistance response and local surface potential (SP) mapping by Kelvin probe force microscopy (KPFM) on a graphene Hall bar sensor. The results show the propagation of an electric charge from the main graphene channel onto the neighboring SiO2 surface. The charge propagation strongly increases with the relative humidity and can be controlled by a bottom-gate voltage used in most sensors based on a field effect transistor (FET) architecture. As proved by the longitudinal resistance measurements, the resulting side charge accumulation has a very small impact on the 2D resistivity of the graphene channel. It has been explained by an application of the Thomas-Fermi theory, proving an efficient screening of side accumulated charge potential caused by a redistribution of the charge inside the wide graphene channel. The combination of a transport resistance response and KPFM provides a deeper understanding of sensors/biosensors functionality and their design features than a simple resistance response usually observed.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (LM2023051, LQ1601 – CEITEC 2020); Grantová Agentura České Republiky, GA ČR, (23-07617S); European Regional Development Fund, ERDF, (CZ.1.05/1.1.00/02.0068)Grant Agency of the Czech Republic [23-07617S]; European Regional Development Fund [CZ.1.05/1.1.00/02.0068]; MEYS CR [LQ1601 - CEITEC 2020]; CzechNanoLab Research Infrastructure - MEYS CR [LM2023051