Tomas Bata University in Zlín
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Curcuma particle size evolution by application of bead milling process and curcuminoids content determination
No full textThe aim of this research was to investigate the effect of curcuma dispersion bead milling on particle size evolution over time. The study of 10 wt.% and 20 wt.% curcuma dispersions revealed that dispersions' polydispersity was decreasing up to 180 min which was found to be the optimum milling time with the volume mean diameter (d4,3) of (11.47 ± 0.85) μm. This diameter was the most effective with respect to the curcuma powder coagulation process attributed to the effect of curcuma oils after the milling time of 180 min. The mechanochemically atomized curcuma was used as a potential source of curcuminoids. By differential scanning calorimetry (DSC), two endothermic peaks were observed and related to curcuma melting effects. Curcumin powder exhibited one broad melting peak at 176 °C. Obtained data indicated that effective mechanochemical treatment makes curcuma powder a highly beneficial supplement applicable in food matrices of the human diet.Tomas Bata University in Zlin, TBU, (IGA/FT/2023/007); Univerzita Palackého v Olomouci, UP, (IGA_PrF_2023_024)Tomas Bata University in Zlin [IGA/FT/2023/007]; Palacky University Olomouc [IGA_PrF_2023_024
Incorporating statistical and machine learning techniques into the optimization of correction factors for software development effort estimation
Get PDFAccurate effort estimation is necessary for efficient management of software development projects, as it relates to human resource management. Ensemble methods, which employ multiple statistical and machine learning techniques, are more robust, reliable, and accurate effort estimation techniques. This study develops a stacking ensemble model based on optimization correction factors by integrating seven statistical and machine learning techniques (K-nearest neighbor, random forest, support vector regression, multilayer perception, gradient boosting, linear regression, and decision tree). The grid search optimization method is used to obtain valid search ranges and optimal configuration values, allowing more accurate estimation. We conducted experiments to compare the proposed method with related methods, such as use case points-based single methods, optimization correction factors-based single methods, and ensemble methods. The estimation accuracies of the methods were evaluated using statistical tests and unbiased performance measures on a total of four datasets, thus demonstrating the effectiveness of the proposed method more clearly. The proposed method successfully maintained its estimation accuracy across the four experimental datasets and gave the best results in terms of the sum of squares errors, mean absolute error, root mean square error, mean balance relative error, mean inverted balance relative error, median of magnitude of relative error, and percentage of prediction (0.25). The p-value for the t-test showed that the proposed method is statistically superior to other methods in terms of estimation accuracy. The results show that the proposed method is a comprehensive approach for improving estimation accuracy and minimizing project risks in the early stages of software development.Faculty of Applied Informatics, Tomas Bata University, (IGA/CebiaTech/2022/001, RVO/FAI/2021/002)Tomas Bata University in Zlin [RVO/FAI/2021/002, IGA/CebiaTech/2022/001
Machine learning model for automated assessment of short subjective answers
Get PDFNatural Language Processing (NLP) has recently gained significant attention; where, semantic similarity techniques are widely used in diverse applications, such as information retrieval, question-answering systems, and sentiment analysis. One promising area where NLP is being applied, is personalized learning, where assessment and adaptive tests are used to capture students' cognitive abilities. In this context, open-ended questions are commonly used in assessments due to their simplicity, but their effectiveness depends on the type of answer expected. To improve comprehension, it is essential to understand the underlying meaning of short text answers, which is challenging due to their length, lack of clarity, and structure. Researchers have proposed various approaches, including distributed semantics and vector space models, However, assessing short answers using these methods presents significant challenges, but machine learning methods, such as transformer models with multi-head attention, have emerged as advanced techniques for understanding and assessing the underlying meaning of answers. This paper proposes a transformer learning model that utilizes multi-head attention to identify and assess students' short answers to overcome these issues. Our approach improves the performance of assessing the assessments and outperforms current state-of-the-art techniques. We believe our model has the potential to revolutionize personalized learning and significantly contribute to improving student outcomes
Wykorzystanie sieci 5G w technologiach bezpieczeństwa
No full textTelephone devices and telecommunication networks have always helped to overcome communication difficulties. Their rapid development is related to the overall digitization of the world. The article dealt with the use of 5G networks in essential sectors of human activities. Although increased risks accompany every step forward, 5G networks and their possible successors will make workouts more efficient in the industry, transport and logistics, healthcare, and personal safety. This publication aims to present the most critical sectors and the use of 5G networks in them.Tomas Bata University in Zln-Faculty of Applied Informatics [IGA/FAI/2023/003
Enhancement of the rheological properties of magnetorheological foam via different constraint volumes foaming approach
Get PDFThe potential of magnetorheological (MR) foam, a recently developed porous smart material, has grown rapidly in recent years. The ability of MR foam to change its properties continuously, actively, and reversibly in response to a controlled external magnetic stimulus is one of its advantages for applications in advanced technology industries. However, its ability to store energy is still relatively low. This study attempts to address this drawback by highlighting a method to improve this ability by enhancing the material's storage modulus by introducing constrained foaming during the fabrication process. MR foam containing 75 wt% carbonyl iron particles (CIPs) was prepared in situ using two foaming approaches: free and constrained foaming. The effect of constraint foaming on the storage modulus enhancement was further investigated by reducing the mold length by 25 % and 50 %. The rheological properties of the fabricated MR foam samples were then examined using a rheometer in both the absence and presence of magnetic fields in an oscillatory shear mode. Thus, this study showed that constraint foaming has successfully improved the properties, especially regarding storage modulus and MR effect. When the mold volume was further reduced by 50 %, the storage modulus increased by about 50 % compared to a free-foaming MR foam at off-state conditions. Meanwhile, the results portrayed a higher storage modulus value under a 0.659 T magnetic field. This positive enhancement was believed to be due to a more compact CIP distribution. Hence, constraint volume MR foams were able to form stronger chain-like structures. The micrograph analysis by digital microscope revealed that the pore size decreased as the mold length was reduced. A shorter mold resulted in a more compact distribution of magnetic particles. As a result, MR foam with constrained foaming, especially at 50 % mold length, has a higher storage modulus. Overall, using constrained foaming to fabricate MR foam could improve the structure and mechanical properties of MR foam for a wide range of smart devices.CIPs, (0.23, 0.43g/ml, 18,22,26,27,33,34); Grantová Agentura České Republiky, GA ČR, (23-07244S); Ministry of Higher Education, Malaysia, MOHE, (FRGS/1/2022/TK10/UTM/02/75); Japan International Cooperation Agency, JICA, (R.K130000.7343.4B696)Ministry of Education Malaysia under Fundamental Research Grant Scheme (FRGS) [FRGS/1/2022/TK10/UTM/02/75]; Japan International Cooperation Agency Fund (JICA Fund) [R. K130000.7343.4B696]; Czech Science Foundation [23-07244S
Self-tuning control of continuous-time two-input two-output system
No full textThe paper presents a comparison of two approaches applied to self - tuning control of a continuous - time two - input two - output system. In first case a continuous - time controller is used and since derivatives of an input and output of a controlled process can not be directly determined, the differential filters and filtered variables are established to substitute primary variables. The filtered variables are then used in the recursive identification procedure. The second method approximates the continuous - time system by a discrete linear model of the same order and a discrete controller is used. The classical recursive least squares method with the directional forgetting is then used to identify the system. Both discrete and continuous - time controllers which were applied to control the system are based on polynomial methods.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (MSM 7088352101); Grantová Agentura České Republiky, GA ČR, (102/05/0271
A managerial review and guidelines for Industry 4.0 factories on cybersecurity
Get PDFThe Fourth Industrial Revolution (Industry 4.0) has created a rebellion in traditional factories by introducing the Internet of Things (IoT) and Cyber-Physical Systems (CPS). This revolution has caused increased automation and customized production, which has occurred through a synergy between customer demands, stocks, and supply chains. This synergy has also exposed factories to potential cyber-attack threats. Although there is extensive literature available on the topic of cyber security, however, business owners still assume cyber security as business preservation. This study sheds light on a step-by-step cyber security aspect of manufacturing factories with Industry 4.0. The study presented possible vulnerabilities and threats to the networks and devices used in a factory by dividing them into various common parameters. We reviewed the proposed literature and provided solutions to Industry 4.0 factories regarding cybersecurity challenges. The reviewed articles are divided into four segments, starting from the purpose of the proposal, the adopted methodology, the proposed cyber security solution, and finally the author’s evaluation. The study reports on a state-of-the-art cyber security solution for Industry 4.0 factories. The characterization of cybersecurity is also proposed concerning management aspects, by showing that every level of organization has its role. The study also highlighted that cybersecurity could play a crucial role in the creation of value for businesses. It is suggested that despite adding an expert system paradigm for cyber security solutions, factories should also adopt new innovative ways, such as machine learning, digital twins, and honeypots. This review highlights that cyber security is not only a technical concern, but it also needs support from multiple actors of the organization to add it to the comprehensive strategy of an Industry 4.0 factory, and every user must be trained and aware of the cybersecurity risks
Mobility of employees and students in a university town in a post-communist country
Get PDFTransportation is undergoing its most significant transformation since the inception of road transport. This transformation is fueled by concerns about climate change and technological advancements. Understanding the current situation in medium-sized cities across Europe is crucial to developing transportation concepts for urban areas within the EU. This study offers insights into the current state of urban mobility in post-communist countries and depicts the current spatial mobility in a medium-sized city. The aim of this study is to evaluate the influence of selected socioeconomic factors on the mobility of employees and students. This study, conducted in 2019, employed quantitative research methods, including a questionnaire survey. In total, 545 employees and students participated in the survey, representing a significant indicator of mobility in the city of Zlín. Data analysis was performed using nonparametric methods. The results indicate a relationship between respondents’ job classification, age group, transportation time, and choice of means of transport. These findings can be applied to countries with similar historical and cultural development backgrounds, such as Poland, Hungary, and Slovakia
Moderating environmental leadership on corporate social responsibility and green innovation of SMEs performance
No full textThe contribution and knowledge of environmental leadership has been questioned on how they aid institutions in their CSR and innovative thinking. The purpose of the investigation was to explore the role of Small and Medium Scale enterprises in emerging nation on how corporate social responsibility (CSR) and green process innovation (GRNI) can help enterprises to achieve environmental (ENVP) and financial performance (FINP). For the analysis of the indicators data was collected from SMEs in the manufacturing sectors of Ghana through questionnaire of 215 participants. The "SmartPLS 3" model was employed to analyze the affiliation between the investigated indicators. The findings demonstrated that CSR had a material impact on ENVP but not on FINP and GRNI. However, GRNI had a favorable and material affiliation with ENVP and FINP of SME's. On exploring the moderating effect of environmental leadership (ENVL) had a favorable affiliation between CSR and green process innovation. The research made a significant contribution to the green theory and practically to researchers and practitioners in manufacturing and other industries who are serious about implementing environmental sustainability and are seeking for a suitable method are anticipated to benefit from this study. It provides a generic approach to implementing CSR that links SME owners and managers, green technologies, green practices, and process management
On the replacement of articular cartilage: The friction of PVA hydrogel layer in hip simulator test
No full textThe present study focuses on friction evaluation of the polyvinyl alcohol (PVA) hydrogel layer, an anticipative material for cartilage replacement. The experiments were carried out in a ball-in-socket configuration using a pendulum hip simulator. The friction coefficients of ceramic-on-hydrogel pairs were compared with those of commercial implants (metal/ceramic heads vs UHMWPE, HXPE and metal/ceramic sockets). The effects of hydrogel ageing and hydration were studied, among others. The use of PVA inserts caused up to 98% reduction in friction coefficient compared to original hip pairs. The application of PVA for local or even complete cartilage replacement seems to be an outstanding opportunity in implantology.Japan Society for the Promotion of Science, KAKEN: JP21H04535; Grantová Agentura České Republiky, GA ČR: 20-00483S, 22-02154SCzech Science Foundation [20-00483S, 22-02154S]; JSPS KAKENHI [JP21H04535