Periodica Polytechnica (Budapest University of Technology and Economics)
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Narrative Review of validation studies of the versions of the Physical Activity Enjoyment Scale for adolescents and older adults
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This article critically examines the Physical Activity Enjoyment Scale (PACES), a widely recognized instrument designed to measure enjoyment associated with physical activity among adolescents and adults. Despite positive physical and mental health outcomes linked to physical activity, significant inactivity persists among youth. This study highlights the importance of enjoyment as a key motivational factor influencing physical activity engagement. Through a narrative synthesis of literature, 17 relevant studies were identified, with 7 selected for detailed analysis, focusing on various PACES versions validated across diverse cultural contexts, including English, German, Chinese, Brazilian Portuguese, and Italian populations. The validation studies confirm PACES's reliability and construct validity, showcasing Cronbach's alpha values indicating strong internal consistency. Furthermore, the research underscores the potential of PACES to explore the interplay between physical activity enjoyment, motivation, and cultural differences. Future directions suggest extending PACES applicability through longitudinal studies, enhancing cultural sensitivity, and developing a digital version for broader, real-time data collection. The findings indicate that PACES remains a valuable tool for researchers and practitioners aiming to foster enjoyment in physical activity and promote healthier lifestyle habits among youth globally
Evaluation of Fatigue-sensitive Details in a Railway Danube Bridge by FE Analysis and SHM Measurements
Full text linkStructural health monitoring system (SHM) has an essential role in the prediction of steel bridges behavior and damage detection. Due to site difficulties and economic reasons, it is not possible to instrumenting all sensitive details within the structure. Finite element modelling is an effective tool for analyzing fatigue-sensitive details, as it enables the extension and interpretation of measured data. This study investigates the structural health monitoring (SHM) system of Southern Railway Danube bridge located in Budapest from fatigue sensitive details point of view. The research applies load testing data for the validation of finite elements models (FEM) which are to be used for specifying the sensitive details. Based on a detailed stress analysis, three fatigue-sensitive areas were identified in the bridge, as follows: 1. the cutout holes of cross girder, 2. the cope-holes, and 3. the transvers welding of bottom flange. Artificial cracks are applied in these details separately to investigate the efficiency of SHM system for crack detection. Stress values at the location of strain gauge points of the SHM system are calculated continuously as cracks size increased, simulating the propagation. The results show that the SHM strain gauges in the current placements not highly efficient to detect the cracks of the investigated details. The study extended to propose strain gauge positions to recognize the crack initiation and propagation in these details
Navigation Framework from a Monocular Camera for Autonomous Mobile Robots
Full text linkGround detection plays a critical role in the perception systems of autonomous mobile robots. The ground is typically characterized as a smooth, drivable surface with uniform texture, making it distinguishable from its surroundings. However, it may exhibit imperfections such as shadows and varying light conditions. This paper presents a framework for the detection of vanishing points, drivable road regions, intersections, and obstacles in the context of autonomous mobile robot navigation. The proposed framework leverages Google's DeepLab v3+ for semantic segmentation of the road, employs the Hough line transform to identify vanishing points and drivable areas, utilizes an intersection analyzer to locate intersections linked to drivable areas, and incorporates a free obstacle detector to identify various objects within drivable regions. Our objective is to simplify the perception of ground-related information in recent methodologies and offer a solution to comprehend and harness the capabilities of these frameworks. The primary significance of this study lies in evaluating the performance of these networks in real-world deployment scenarios. The evaluation results demonstrate that our proposed framework achieves high accuracy across diverse and challenging situations. Consequently, the developed framework holds promise for integration into autonomous mobile robots (AMRs)
Changes in the Use of Passenger Rail Transport in Poland due to the COVID-19 Pandemic
Full text linkRail transportation in Poland has been experiencing substantial year-over-year growth, contributing significantly to the national economy. Recent investments in the rail network have enhanced its efficiency and capacity, encouraging an increasing number of individuals to opt for more sustainable modes of transportation. Nevertheless, the outbreak of the COVID-19 pandemic severely disrupted planned innovations within the sector. During the pandemic, stringent restrictions on mobility and interpersonal contact were imposed. The objective of this article is to examine the perspectives of Polish citizens regarding the impact of the coronavirus pandemic on passenger rail traffic and their travel preferences. To this end, a survey was conducted. The results indicated that the pandemic led to a 27% decline in the use of rail transportation in Poland, primarily attributed to mobility restrictions and safety concerns. The research findings suggest that the continued development and modernization of rail infrastructure could facilitate the restoration of public interest in rail travel, particularly in the context of environmental considerations and the enhancement of travel comfort
