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Authors - 10204
Austin E. Schumacher
60005948200
Ildikó Kiss-Szarvák
57204088260
Borbála Berki
57203686505
Tamás Jakubík
57205246757
Publications - 6515
Development of a multibody model for go-karts considering frame flexibility
Publication Name: Pollack Periodica
Publication Date: 2024-10-16
Volume: 19
Issue: 3
Page Range: 66-73
Description:
This study focuses on the optimization dynamics of racing go-karts, which is heavily influenced by the frame's stiffness. Lacking suspensions and differentials, go-karts rely on the frame stiffness for wheel balancing and skid prevention by lifting the inner rear wheel during turns. Utilizing a rigid-flexible model in MSC Software ADAMS View, validated by frame deformation measurements, this research integrates finite element analysis with multibody techniques. The model, leverages computer aided design files for frame geometry and employs finite element analysis for frame validation. It facilitates evaluating go-kart dynamics through simulations, aiding in maneuver testing and design optimization. This approach provides a comprehensive framework for advancing go-kart designs.
Open Access: Yes
Changes in primitive reflexes in older adults and their relationship to mental health indices: An experimental investigation
Publication Name: Experimental Gerontology
Publication Date: 2024-10-15
Volume: 196
Issue: Unknown
Page Range: Unknown
Description:
The reemergence of primitive reflexes (PRs) in older age is related to cognitive impairment. Currently, there are no means to prevent or slow their reappearance, but research evidence exists for their control in children. Therefore, this experiment investigated whether a 16-week special sensorimotor exercise program could benefit older adults and whether the intervention-induced changes (if any) may be associated with various indices of mental health. Of 115 adults over 60, 95 completed the study (mean age = 76.37 ± SD = 7.04 years, 22 % men). The experimental group (n = 38) showed an almost threefold decline in PRs compared to controls. In contrast, the control group (n = 57) exhibited a nearly threefold increase in PRs compared to the intervention group. Cognitive function increased in the experimental but not in the control group. Changes in PRs over the 16-week intervention were positively related to negative mental health indices (hopelessness and perceived stress) and negatively related to well-being. These findings suggest that the here-presented mild sensorimotor exercises could affect older adults' reemerging PRs and that changes in PRs are associated with mental health benefits. These results may open new research avenues toward preventing cognitive and psychological decline in older adults.
Open Access: Yes
Constructability-based design approach for steel structures: From truss beams to real-world inspired industrial buildings
Publication Name: Automation in Construction
Publication Date: 2024-10-01
Volume: 166
Issue: Unknown
Page Range: Unknown
Description:
This paper presents an optimization framework for steel trusses. The authors implemented a penalty-based approach to optimise the size, shape, and topology based on a dynamic grouping strategy to address the constructability challenges. The main contribution of the paper is the use of damped exponential constructability penalties. This approach ensures optimal designs by balancing structural complexity, through standardization in design, and minimizing the total number of members and variety of sections, with the overall structural cost. The paper also presents a detailed analysis that underscores the sensitivity of the optimization convergence to the algorithmic hyperparameters, emphasizing the role of cross-section assignments and stabilization of truss piece counts. The optimization framework is validated on a trussed roof structure based on the findings from the single truss optimization. The best truss topology proved to be the Howe truss configuration, highlighting its efficiency in meeting the defined objective function.
Open Access: Yes
Mental and physical health of yoga practitioners women in relation to exercise parameters
Publication Name: Mentalhigiene Es Pszichoszomatika
Publication Date: 2023-05-19
Volume: 24
Issue: 1
Page Range: 58-74
Description:
Introduction: Numerous international studies have shown that yoga practice has a positive effect on the physical and mental condition of healthy people and can play a role in the complementary treatment of certain diseases with appropriate guidance. Research on yoga practitioners has found positive correlations between several health indicators and the frequency of yoga practice and, in part, the yoga practice time. In terms of women s health, yoga has been shown to have a positive effect in relieving depression, anxiety and stress and several somatic symptoms. Objective: The aim of our study is to assess the subjective mental and physical symptoms of the health of Hungarian women practicing yoga, and to examine the associations between these variables between groups separated by yoga time and frequency. Methods: The study sample consisted of 457 healthy women with a mean age of 42.28 years (SD = 11.72), yoga practitioners 72%, and yoga instructors 27.7%. The Depression Anxiety Stress Scale-21 (DASS-21), Positive and Negative Affect Schedule (PANAS), Self-rated Health, and the Patient Health Questionnaire Somatic Symptom Severity Scale (PHQ-15) were used to measure the variables. Differences between the formed groups were analyzed by Kruskal-Wallis H and Mann-Whitney U tests. Results: We found a statistically significant difference between the three yoga time groups (beginner 1-6 months, intermediate 7-35 months, advanced ≥3 years) in depression (x2(2, n = 457) = 23.205, p < 0.001), anxiety (x2( 2, n = 457) = 9.489, p = 0.009), stress (x2(2, n = 457) = 27.224, p < 0.001), positive affect (x2(2, n = 456) = 7.689, p = 0.021), negative affect (x2( 2, n = 456) = 46.177, p < 0.001), self-rated health (x2(2, n = 457) = 28.862, p < 0.001) and somatic symptoms (x2(2, n = 455) = 26.022, p < 0.001) score. We also found a significant differences between the two yoga frequency groups (1-2 times per week and 3-7 times per week) in depression (U(1) = 19148.50, n1 = 161, n2 = 295, Z =-3.508, p < 0.001), stress (U(1) = 19588.50, n1 = 161, n2 = 295, Z =-3.107, p = 0.002), positive affect (U(1) = 18189.00, n1 = 161, n2 = 294, Z =-4.090, p < 0.001), negative affect (U(1) = 18456.50, n1 = 161, n2 = 294, Z =-3.894, p < 0.001), self-rated health (U(1) = 18244.00, n1 = 161, n2 = 295, Z =-4.873, p < 0.001) and somatic symptoms (U(1) = 19777.50, n1 = 160, n2 = 294, Z =-2.817, p = 0.005). A medium effect size difference was observed for negative affectivity and small effect size differences were observed for the other measured variables. Conclusions: Yoga could be recommended for relieving depression, anxiety, stress, and somatic symptoms, as well as a possible coping strategy for dealing with stress for healthy women. The results suggest that prolonged yoga practice (in years) or repeated physical exercises of yoga (asana) several times a week (3 or more times) may provide the greatest health benefits.
Open Access: Yes
Modelling of the Torsional Simple Shear Test with Randomized Tresca Model Properties in Midas GTS NX
Publication Name: Geotechnical and Geological Engineering
Publication Date: 2023-05-01
Volume: 41
Issue: 3
Page Range: 1937-1946
Description:
The dynamic properties of soil obtained from the torsional simple shear test (TOSS) are assumed to be uniform throughout the specimen. For some exceptional soils, this may hold true, but for the most majority of soils that we examine, it is obviously not the case, and this level of non-uniformity depends on the conditions in which the soil was formed. In this paper, we discuss a method of modelling inherently non-uniform soil specimens by representing them with elements that have an elasto-plastic simple Tresca material model with different properties (Elastic young modulus and yield stresses). The combination of properties that can simulate the nonlinear behaviour of the soil is found and calibrated using a model of the TOSS test built in the finite element software Midas GTS NX. Furthermore, the influence of rigid inclusions in the soil is studied and the results show an increase in stiffness with the increasing percentage of inclusion in the soil.
Open Access: Yes
Forward and backward fuzzy rule base interpolation using fuzzy geometry
Publication Name: Iranian Journal of Fuzzy Systems
Publication Date: 2023-05-01
Volume: 20
Issue: 3
Page Range: 127-146
Description:
Fuzzy rule interpolation (FRI) predicts an accountable outcome of a possible course of action in sparse fuzzy rule base system (FRBS). The geometry based linear fuzzy rule interpolation (GLFRI) is extended for multi-dimensional fuzzy rule base interpolation. Expansion/contraction (EC) of triangular, trapezoidal and complex polygonal fuzzy sets has been also proposed which enables the proposed FRI method to incorporate with fuzzy rules which include triangular, trapezoidal, hexagonal or complex fuzzy sets. The study further extends to introduce the process of backward rule base interpolation. It has been shown that the scale and move transformation-based FRI method can yield a non-convex fuzzy consequent which can be avoided by using the proposed method. The proposed method performs better without any risk of obtaining non-convex fuzzy consequent. The efficiency of proposed forward and backward FRI methods is projected with several numerical examples. A detailed comparison of EC transformation with scale and move transformation is also presented here.
Open Access: Yes
DETECTION PROCESS OF ENERGY LOSS IN ELECTRIC RAILWAY VEHICLES
Publication Name: Facta Universitatis Series Mechanical Engineering
Publication Date: 2023-04-01
Volume: 21
Issue: 1
Page Range: 81-99
Description:
The paper deals with the detection process of energy loss in electric railway hauling vehicles. The importance of efficient energy use in railways and cost-effective rail transport tendency toward regenerative braking energy are considered. In addition, the current situation and improvement opportunities to achieve efficient energy use are examined. Seven measurement series were performed with scheduled Railjet trains between Hegyeshalom and Győr railway stations in Hungary. This railway section is related to the Hungarian State Railways' No. 1 main railway line (between Budapest-Kelenföld and Hegyeshalom state board), which is a part of the international railway line between Budapest and Vienna (capitals of Hungary and Austria, respectively). This double-track, electrified railway line with traditional ballasted superstructures and continuously welded rail tracks is important due to the international passenger and freight transport between Germany, Austria, and Hungary. The value of the regenerative braking energy can be even 20-30% of the total consumed energy. This quite enormous untapped energy can be used for several aims, e.g., for comfort energy demand (air conditioning, heating-cooling, lighting, etc.) or energy-intensive starts. The article also investigates the optimization of regenerative braking energy by seeking the energy-waste locations and the reasons for the significant consumption. The train operator's driving style and habit have been identified as one of the main reasons. Furthermore, train driver assistance systems are recommended to save energy, which is planned for future research.
Open Access: Yes
Screening of Domestic Cats from North-Eastern Hungary for Hepatozoon felis and Cytauxzoon europaeus That Cause Infections in Local Wildcat Populations
Publication Name: Pathogens
Publication Date: 2023-05-01
Volume: 12
Issue: 5
Page Range: Unknown
Description:
Among vector-borne protozoa Hepatozoon felis and Cytauxzoon europaeus are considered emerging species in felids in Europe. To investigate the presence of these two protozoa 127 domestic cats and 4 wildcats were screened by PCRs targeting the 18S rRNA gene of Hepatozoon spp. and piroplasms, as well as the cytb gene of Cytauxzoon spp. The samples were collected inside and outside a region of Hungary, where both protozoan groups are endemic in wildcats. Among domestic cats, one proved to be infected with H. felis. Furthermore, spleen samples of four wildcats were also examined, among which three tested positive for H. felis, and one had co-infection with C. europaeus. Importantly, H. felis from the co-infected wildcat belonged to genogroup II, similarly to H. felis from the positive domestic cat. Based on phylogenetic evidence, this genogroup probably represents a separate species from genogroup I of H. felis, which was hitherto reported from Mediterranean countries in Europe. The two other wildcats also harbored H. felis from genogroup I. Neither Hepatozoon nor Cytauxzoon infections were detected outside the recently discovered endemic region. In conclusion, this study demonstrates for the first time in Europe that H. felis from genogroup II may emerge in free-roaming domestic cats in regions where this protozoan parasite is endemic in wildcats.
Open Access: Yes
Spectroscopi c Anal ysi s of Chrysoti l e Asbestos and i ts Environmental Resistance in Asbestos Cement Waste Products
Publication Name: Pertanika Journal of Science and Technology
Publication Date: 2024-10-01
Volume: 32
Issue: 6
Page Range: 2441-2458
Description:
Most asbestos-related studies have focused on asbestos exposure risks, their associated health implications, and waste management issues. Our research introduced a unique perspective that has rarely been explored: the impact of environmental factors on asbestos cement products. The novelty of the study is that, in contrast to previous research, in addition to determining the material quality of asbestos, it analyses the trace materials, additives and the emissive nature of chrysotile fibers. This study aims to identify the chrysotile-asbestos content in three common asbestos cement products found in Hungary, with regard to the release of their fibers upon exposure to the environment and to identify trace elements that could be used to identify the origin and function of each of these products. Our analyses revealed the presence of chrysotile in each tested sample, with spectral matches ranging from 59.6% to 86.7%. Asbestos cement products exposed to various environmental influences for long periods showed a greater chrysotile emission capacity than those unexposed or hermetically sealed ones. Additionally, we established that all asbestos cement products contained glass fibers, with an average spectral match of 62.1%. We further identified polysilicate in the materials with an average spectral match of 66.0%, as it was included in asbestos cement products to enhance their heat resistance. Our results pave the way for a new methodology for assessing asbestos cement products with regard to the implementation of their trace element level assessments.
Open Access: Yes
