Tomas Bata University in Zlín
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Construction of a generator for power frequency magnetic field immunity test
No full textThe power frequency magnetic field immunity test is a common test applied to a large variety of devices that must be checked for electromagnetic compatibility. Implementing this test is not difficult since it involves working with frequencies at which the generated magnetic field can be considered quasi-stationary. Considering the high price level of devices intended for use in electromagnetic compatibility laboratories, it may be worth contemplating assembling the equipment for this test on one's own. This paper includes a discussion on the requirements given by the relevant standards and their implications for the design of the test signal generator. Additionally, a complete design process for such equipment is provided, along with a discussion on the possibility of further improvements. The design of the test coil is adapted to allow its excitation from a powerful low-frequency amplifier, which opens up possibilities for the use of more advanced drivers. However, the test coil can also be powered using a normal mains transformer, simplifying the design of the entire deviceIGA/CebiaTech/2023/003Internal Grant Agency at TBU in Zlin [IGA/CebiaTech/2023/003]; internal funds of Faculty of Applied Informatics at TBU in Zli
Motion analysis using global navigation satellite system and physiological data
Get PDFMotion analysis using wearable sensors is an essential research topic with broad mathematical foundations and applications in various areas, including engineering, robotics, and neurology. This paper presents the use of the global navigation satellite system (GNSS) for detecting and recording the position of a moving body, along with signals from additional sensors, for monitoring of physical activity and analyzing heart rate dynamics during running on route segments of different slopes and speeds. This method provides an alternative to the heart monitoring on the treadmill ergometer in the cardiology laboratory. The proposed computational methodology involves digital data preprocessing, time synchronization, and data resampling to enable their correlation, feature extraction both in time and frequency domains, and classification. The datasets include signals acquired during ten experimental runs in the selected area. The motion patterns detection involves segmenting the signals by analysing the GNSS data, evaluating the patterns, and classifying the motion signals under different terrain conditions. This classification method compares neural networks, support vector machine, Bayesian, and k-nearest neighbour methods. The highest accuracy of 93.3 % was achieved by using combined features and a two-layer neural network for classification into three classes with different slopes. The proposed method and graphical user interface demonstrate the efficiency of multi-channel and multi-dimensional signal processing with applications in rehabilitation, fitness movement monitoring, neurology, cardiology, engineering, and robotic systems
Ideal marker for targeted axillary dissection (IMTAD): a prospective multicentre trial
Get PDFBackground: Targeted axillary dissection (TAD) is an established method for axillary staging in patients with breast cancer after neoadjuvant chemotherapy (NAC). TAD consists of sentinel lymph node biopsy and initially pathological lymph node excision, which must be marked by a reliable marker before NAC.
Methods: The IMTAD study is a prospective multicentre trial comparing three localisation markers for lymph node localisation (clip + iodine seed, magnetic seed, carbon suspension) facilitating subsequent surgical excision in the form of TAD. The primary outcome was to prospectively compare the reliability, accuracy, and safety according to complication rate during marker implantation and detection and marker dislodgement.
Results: One hundred eighty-nine patients were included in the study—in 135 patients clip + iodine seed was used, in 30 patients magnetic seed and in 24 patients carbon suspension. The complication rate during the marker implantation and detection were not statistically significant between individual markers (p = 0.263; p = 0.117). Marker dislodgement was reported in 4 patients with clip + iodine seed localisation (3.0%), dislodgement did not occur in other localisation methods (p = 0.999). The false-negativity of sentinel lymph node (SLN) was observed in 8 patients, the false-negativity of targeted lymph nodes (TLN) wasn´t observed at all, the false-negativity rate (FNR) from the subcohort of ypN + patients for SLN is 9.6% and for TLN 0.0%.
Conclusion: The IMTAD study indicated, that clip + iodine seed, magnetic seed and carbon suspension are statistically comparable in terms of complications during marker implantation and detection and marker dislodgement proving their safety, accuracy, and reliability in TAD. The study confirmed, that the FNR of the TLN was lower than the FNR of the SLN proving that the TLN is a better marker for axillary lymph node status after NAC.
Trial registration: NCT04580251.
Name of registry: Clinicaltrials.gov.
Date of registration: 8.10.2020.MMCI, (00209805
Barriers to immigrant entrepreneurship: A causal relationship analysis of the Asian immigrant entrepreneurs in Germany employing the DEMATEL approach
Get PDFResearch background: Entrepreneurship and migration are top priorities on many national and international agendas. As a result, entrepreneurship is one of the most popular strategies immigrants use to avoid unemployment in a host country. However, studies lack to discuss causal relationships among key barriers to immigrant entrepreneurs.
Purpose of the article: This study attempts to fill the knowledge gap and investigate the causal relationship between the primary obstacles faced by Asian immigrant entrepreneurs in Germany.
Methods: A predesigned questionnaire was used in face-to-face interviews with Asian business owners in Germany for the study, and the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method of data analysis was used.
Findings & value added: The findings reveal that lack of sufficient financial resources to establish a business, high market competition, and a lack of knowledge of the local language of the host country are the most significant barriers, among others, which may severely hamper Asian immigrant business performance and have a considerable impact on their entrepreneurial decision. At the same time, lack of professional knowledge & skills, problems with rules & regulations, and cultural differences are among the least essential obstacles for Asian immigrant entrepreneurs. The findings show that unfamiliarity with the local language, problems with rules and regulations, cultural differences, and lack of international business experience are associated with the causer category. However, lack of enough capital to establish a venture, lack of professional knowledge and skills, difficulty in access to financial resources, and high market competition relate to the receiver category. This research generates value for policymakers, particularly those participating in migration studies. One of the study's novelties is using the DEMATEL framework for decision-making on barriers to immigrant entrepreneurship in the European context.The Implementation Framework and Business Model of the Internet of Things, Industry 4.0 and Smart Transport [NFP313010BWN6
Where do tourism tokens travel to and from?
No full textThis study aims to identify the sources of spillovers affecting tourism tokens and classify the type of assets to which they correspond. Using daily data for different asset classes from June 2018 through November 2022, we employ a TVP-VAR methodology to test the connectedness between two tourism tokens, two leading travel equity indices, and the two dominant cryptocurrencies, namely, Bitcoin and Ethereum. The findings show that tourism tokens are relatively independent of fluctuations in the traditional sources affecting the travel and leisure sector, such as the U.S. dollar, the price of oil, or travel equity indices. These results hint that tourism tokens are more closely related to cryptocurrencies rather than pure travel goods. The results may help decision-makers in the travel and hospitality industries considering the use of tourism tokens identify the potential forces impacting them
Magneto-responsive hyaluronan hydrogel for hyperthermia and bioprinting: Magnetic, rheological properties and biocompatibility
Get PDFMagneto-responsive soft hydrogels are used for a number of biomedical applications, e.g., magnetic hyperthermia, drug delivery, tissue engineering, and neuromodulation. In this work, this type of hydrogel has been fabricated from hyaluronan (HA) filled with a binary system of Al2O3 nanoparticles and multicore magnetic particles (MCPs), which were obtained by clustering of superparamagnetic iron oxide FeOx NPs. It was established that the presence of diamagnetic Al2O3 has several positive effects: it enhances the hydrogel storage modulus and long-term stability in the cell cultivation medium; prevents the magnetic interaction among the MCPs. The HA hydrogel provides rapid heating of 0.3 °C per min under exposure to low amplitude radio frequency alternating magnetic field. Furthermore, the magneto-responsive hydrogel was successfully used to encapsulate cells and extrusion-based 3D printing with 87±6% cell viability, thus providing a bio-ink. The combination of high heating efficiency, softness, cytocompatibility, and 3D printability of magnetic HA hydrogel leads to a material suitable for biomedical applications.DKRVO, (RP/CPS/2022/003, RP/CPS/2022/005); Program Multilateral Scientific and Technological Cooperation in the Danube Region, (8X20041); Tomas Bata University in Zlin, TBU, (22–33307S, CZ.02.2.69/0.0/0.0/19_073/0016941, IGA/FT/2023/006); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Grantová Agentura České Republiky, GA ČR, (RP/CPS/2022/001)Ministry of Education, Youth and Sports of the Czech Republic-DKRVO [RP/CPS/2022/003, RP/CPS/2022/005]; Program Multilateral Scientific and Technological Cooperation in the Danube Region [8X20041]; TBU [IGA/FT/2023/006]; Czech Science Foundation [22-33307S]; Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/001
Impact of boundary control methods on bound-constrained optimization benchmarking
No full textDespite initial indifference towards boundary control methods (BCM) in the context of metaheuristic algorithm design, benchmarking, and execution, our research demonstrates their critical importance. This study investigates how the choice of a particular BCM can profoundly influence the performance of competitive algorithms. We analyzed the top three algorithms from the 2017 and 2020 IEEE CEC competitions, posing the following question: Could a change in BCM usage alter an algorithm’s overall performance and, consequently, its ranking among competitors? Our findings reveal that paying attention to BCMs can lead to significant improvements. The experiments revealed that BCM selection can significantly impact an algorithm’s performance and, in some instances, its competition rank. However, most authors omitted to mention the implemented BCM, resulting in poor reproducibility and deviating from recommended benchmarking practices for metaheuristic algorithms. The conclusion is that the BCM should be considered another vital metaheuristics input variable for unambiguous reproducibility of results in benchmarking and for a better understanding of population dynamics.Tomas Bata University in Zlin, TBU, (IGA/CebiaTech/2023/004)Internal Grant Agency of the Tomas Bata University in Zlin [IGA/CebiaTech/2023/004
Latest developments in minimally invasive spinal treatment in Slovakia and its comparison with an open approach for the treatment of lumbar degenerative diseases
Get PDFThe study describes the benefits of MIS-TLIF (minimally invasive transforaminal lumbar interbody fusion) and compares them with OTLIF (open transforaminal lumbar interbody fusion). It compares blood loss, length of hospitalization stays (LOS), operation time, and return of the patient to the environment. A total of 250 adults (109 males and 141 females), mean age 59.5 & PLUSMN; 12.6, who underwent MIS-TLIF in the Neurosurgery Clinic (NSC) Ruzomberok, Slovakia, because of lumbar degenerative diseases (LDD), participated in this retrospective study. Data were obtained from the patients' medical records and from the standardized Oswestry Disability Index (ODI) index questionnaire. To compare ODI in our study sample, we used the Student's Paired Sample Test. To compare the MIS-TLIF and OTLIF approaches, a meta-analysis was conducted. Confidence intervals were 95% CI. The test of homogeneity (Chi-square (Q)) and the degree of heterogeneity (I-2 test) among the included studies were used. Statistical analyses were two-sided (& alpha; = 0.05). All monitored parameters were significantly better in MIS-TLIF group: blood loss (p < 0.001), operation time (p < 0.001), and ODI changes (p < 0.001). LOS (p < 0.042) were close to the significance level. ODI in the study sample decreased by 33.44% points after MIS-TLIF, and it significantly increased as well (p < 0.001). The percentage of patients who were satisfied with the surgery they underwent was 84.8%. The study confirmed that the MIS-TLIF method is in general gentler for the patient and allows the faster regeneration of patient's health status compared to OTLIF
3D printed Fused Deposition Modeling (FDM) capillaries for chemiresistive gas sensors
Get PDFThis paper discusses the possible use of 3D fused deposition modeling (FDM) to fabricate capillaries for low-cost chemiresistive gas sensors that are often used in various applications. The disadvantage of these sensors is low selectivity, but 3D printed FDM capillaries have the potential to increase their selectivity. Capillaries with 1, 2 and 3 tiers with a length of 1.5 m, 3.1 m and 4.7 m were designed and manufactured. Food and goods available in the general trade network were used as samples (alcohol, seafood, chicken thigh meat, acetone-free nail polish remover and gas from a gas lighter) were also tested. The "Vodka" sample was used as a standard for determining the effect of capillary parameters on the output signal of the MiCS6814 sensor. The results show the shift of individual parts of the signal in time depending on the parameters of the capillary and the carrier air flow. A three-tier capillary was chosen for the comparison of gas samples with each other. The graphs show the differences between individual samples, not only in the height of the output signal but also in its time characteristic. The tested 3D printed FDM capillaries thus made it possible to characterize the output response by also using an inexpensive chemiresistive gas sensor in the time domain.Internal Grant Agency of Tomas Bata University in Zlín, (IGA/FT/2023/003); Vysoké Učení Technické v Brně, BUT, (FEKT-S-20-6215
Use of Virtual Reality in polygraph testing
No full textThe primary objective of this research is to investigate the potential use of virtual reality technology in the process of criminal investigations, specifically in relation to the use of polygraph technology. A comparative analysis of existing research on this topic was conducted to explore the relationship between immersion in VR and emotions, in order to understand how to effectively design and implement polygraph testing within VR.Internal Grant Agency of Tomas Bata University in Zlin; Department of Security Engineering, Faculty of Applied Informatics [IGA/FAI/2023/003]; [IGA/FAI/2022/006]Department of Security Engineering, Faculty of Applied Informatics, (IGA/FAI/2022/006, IGA/FAI/2023/003); Internal Grant Agency of Tomas Bata University in Zli