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Found 5164 publications
How realistic a bicycle simulator can be? - A validation study
Publication Name: Multimodal Transportation
Publication Date: 2025-03-01
Volume: 4
Issue: 1
Page Range: Unknown
Description:
The aim of this research is to objectively and subjectively validate the virtual reality Bicycle Simulator (BS) developed using off-the-shelf components at the University of Győr, Hungary. To this end, this research compares the performance of 32 participants in two real-world environments (Site 1: separated bicycle-pedestrian path and Site 2: advisory bicycle lane) and in their replication in virtual reality (VR). The objective measures collected for the comparison include speed and Cumulative Lateral Position (CLP), whereas subjective measures include the Perceived Level of Realism (PLR) based on participants’ self-reported perceptions in a post-experiment questionnaire. PLR is a new indicator that we propose using subjects' perceptions of speed, BS control, and VR representation. The combination of these subjective and objective measures is proposed as the Degree of Realism (DR) to standardise the classification of the realism level of a bicycle simulator. Subjectively, the results indicate that the BS provides a high level of safety and comfort for conducting such research. Subject characteristics have no significant influence on VR sickness scores or Perceived Level of Realism. Objectively, for both speed and CLP, we found no significant difference between on-site and the simulation measurements in the case of Site 1, but otherwise for Site 2. However, subjects were not able to accurately perceive either the actual or the relative differences. In conclusion, our bicycle simulator is a safe and comfortable traffic safety research tool that needs further improvement. The proposed preliminary concept of the degree of realism requires further investigation.
Open Access: Yes
Key characteristics and role of lead users in medical device innovations: An exploratory study
Publication Name: Journal of Innovation and Knowledge
Publication Date: 2025-03-01
Volume: 10
Issue: 2
Page Range: Unknown
Description:
Developing medical device innovations is a lengthy and costly endeavor, so engaging the right participants early in the process is crucial. While much of the existing literature focuses on procedural aspects of innovation, the human factors that influence success are often overlooked. The Lead User Method is designed to identify key contributors based on their ability to stay ahead of market trends and realize significant benefits. However, it has been criticized for inadequacies in its identification process. To address this gap, our study distinguishes seven key personal characteristics of medical lead users that are essential for successful co-created new product development. Through case studies and semi-structured interviews, we demonstrate that engaging lead users throughout the new product development process—regardless of product complexity—enhances product-market fit and profitability. Their involvement becomes increasingly critical as the process advances, particularly during the market diffusion phase. Our research refines the Lead User Method's identification process and provides actionable insights for decision-makers, reducing uncertainty in medical device innovation while lowering development costs and time and increasing product-market fit and profitability.
Open Access: Yes
Script-Based Material and Geometrical Modeling of Steel–Concrete Composite Connections for Comprehensive Analysis Under Varied Configurations
Publication Name: Applied Sciences Switzerland
Publication Date: 2025-03-01
Volume: 15
Issue: 6
Page Range: Unknown
Description:
The behavior of steel–concrete composite structures is significantly influenced by the efficiency of the shear connections that link the two materials. This research examines the performance of stud shear connectors, with an emphasis on analyzing the effect of different geometric design parameters. A computational model was created utilizing Python 3.13 to enable thorough digital monitoring of the influence of these parameters on the structural performance of composite connections. Developed within the ABAQUS framework, the model integrates geometric nonlinearity and the Concrete Damage Plasticity (CDP) approach to achieve detailed simulation of structural behavior. Essential design aspects, including stud diameter, stud height, head dimensions, and spacing in both longitudinal and transverse directions, were analyzed. The Python-based parametric model allows for easy modification of design parameters, ensuring efficiency and minimizing modeling errors. The significance of stud diameter changes was analyzed in accordance with Eurocode standards and previous studies. It was found that stud length has a reduced effect on structural performance, particularly when considering the concrete properties used in bridge construction, where compressive failure of the concrete zone is more critical at lower concrete strengths. Additional factors, such as stud head dimensions, were investigated but were found to have minimal effect on the behavior of steel–concrete composite connections. Longitudinal stud spacing emerged as a critical factor influencing structural performance, with optimal results achieved at a spacing of 13d. Spacings of 2d, 3d, and 4d demonstrated overlapping effects, leading to significant performance reductions, as indicated by comparisons of ultimate load and force–displacement responses. For transverse spacing, closer stud arrangements proved effective in reducing the likelihood of slip at the steel–concrete interface, enhancing composite action, and lowering stress concentrations. Additionally, reducing the transverse distance between studs allowed for the use of more shear connectors, increasing redundancy and enhancing performance, especially with grouped-stud connectors (GSCs).
Open Access: Yes
DOI: 10.3390/app15063095
Hypertension and sports activity
Publication Name: Cardiologia Hungarica
Publication Date: 2025-03-01
Volume: 55
Issue: 1
Page Range: 34-39
Description:
This summary article reviews the complex relationship between hypertension and sports, addressing key aspects of prevalence, risk factors, and management strategies. Hypertension is a leading cause of cardiovascular disease and mortality, and while regular exercise generally provides cardioprotective effects, certain sports disciplines and lifestyle choices may elevate blood pressure levels in athletes. The article highlights the role of isometric training, high body mass, and the use of performance-enhancing substances as contributors to increased risk. Additionally, it explores the implications of high blood pressure on both athletic performance and long-term cardiovascular health. Diagnostic challenges are discussed, emphasizing the limitations of routine measurements and the need for advanced tools such as ambulatory blood pressure monitoring. Updated European guidelines are presented as a framework for accurate hypertension diagnosis and risk assessment among athletes. Management approaches prioritize lifestyle interven-tions, including dietary changes, stress reduction, and tailored exercise programs. When necessary, pharmacological treatments are recommended with careful consideration of doping regulations and potential impacts on athletic perfor-mance. This article underscores the importance of individualized care in addressing hypertension in athletes, advocat-ing for a multidisciplinary approach that integrates medical, nutritional, and training expertise. By consolidating current evidence, the article aims to provide practical guidance for clinicians, treating athletes and patients with regular physical activities, to better understand and manage hypertension in this population.
Open Access: Yes
Exploring the impact of China's low carbon energy technology trade on alleviating energy poverty in Belt and Road Initiative countries
Publication Name: Energy
Publication Date: 2025-03-01
Volume: 318
Issue: Unknown
Page Range: Unknown
Description:
The objective of this study is to analyze how low-carbon technology imports such as wind turbines, solar panels, carbon capture equipment, and biomass systems from China affect Belt and Road Initiative (BRI) countries’ energy poverty. Additionally, we analyze the role of financial development, deliberative democracy, economic complexity, human development, and telecommunications infrastructure on energy poverty in BRI countries. We use 69 countries from Belt and Road initiative countries and a sample period from 2000 to 2019. We classify these countries according to the IMF classification of advanced, emerging and low-income developing countries. We employ the instrumental variable generalized method of moments (IV-GMM) approach as the main technique to take care of the endogeneity concerns inherent in the model, as well as a robust quantile-based technique called the method of moments quantile regression estimator (MMQREG). Our results reveal that low-carbon technology trade from China does not significantly alleviate energy poverty in the BRI countries. Financial development increases energy poverty while deliberative democracy decreases it. Economic complexity, as well as human development, negatively affects energy poverty, while telecommunications infrastructure does not affect energy poverty significantly. Based on the results, policy implications are provided.
Open Access: Yes
Enhancing the Nutritional Quality of Low-Grade Poultry Feed Ingredients Through Fermentation: A Review
Publication Name: Agriculture Switzerland
Publication Date: 2025-03-01
Volume: 15
Issue: 5
Page Range: Unknown
Description:
Feed accounts for up to 80% of poultry production costs, with high-quality grains such as soybean meal and corn traditionally serving as primary ingredients. However, increasing costs and competition for these grains have driven interest in low-grade and unconventional feed ingredients, including by-products like rapeseed meal and cottonseed meal. These alternatives are often constrained by high fiber content, anti-nutritional factors, and reduced nutrient bioavailability. Fermentation has emerged as a promising strategy to address these limitations, enhancing digestibility, palatability, and antioxidant properties while degrading harmful compounds such as tannins, trypsin inhibitors, and free gossypol. Solid- and liquid-state fermentation techniques utilize microbial inoculants, including lactobacilli and Bacillus species, to enzymatically break down complex macromolecules, thereby releasing essential nutrients. When combined with pretreatments like enzymatic hydrolysis, fermentation significantly improves the nutritional quality of feed ingredients while reducing costs without compromising poultry health or performance. This review examines the mechanisms, benefits, and challenges of fermentation techniques in poultry feed production, underscoring the importance of further research to optimize fermentation parameters, identify novel microbial strains, and ensure scalability and safety in industrial applications.
Open Access: Yes
Models, modeling and model-based systems in the era of computers, machine learning and AI
Publication Name: Computers and Chemical Engineering
Publication Date: 2025-03-01
Volume: 194
Issue: Unknown
Page Range: Unknown
Description:
Models, representing a system under study with respect to problems such as process design, process control, product synthesis and many more, are at the core of most computer-aided solution techniques. The representation of a system through a model is done in different ways, such as, symbols, data, mathematical equations, and/or some combination of these. The workflow or process of creating a proxy mathematical representation (model) of a given target system is referred to as modeling. Model-based software tools incorporate the developed models within the steps of their systematic workflow through simultaneous or decomposed solution strategies related to synthesis, design, analysis, etc., of specific systems. In this perspective paper we highlight the various ways systems can be represented by models, the different ways the required models are developed through modeling techniques, and examples of model-based software tools developed to solve different process and product engineering problems. Two types of systems - process systems and chemical systems, are considered. Important issues and challenges are highlighted and perspectives on how they can be addressed are presented.
Open Access: Yes
Water stress-based price for global sustainability: a study using generalized global sustainability model (GGSM)
Publication Name: Clean Technologies and Environmental Policy
Publication Date: 2025-03-01
Volume: 27
Issue: 3
Page Range: 1131-1150
Description:
Abstract: Considering the importance of water in the global Food-Energy-Water nexus, stress-dependent water pricing can be a valuable tool to achieve water sustainability. Given the large variability in water availability and demands across the globe, such mechanism should be implemented at regional scale. However, water pricing explicitly incorporating regional water stress has been rarely studied and used. Here, the generalized global sustainability model is modified and used to model continent-level stress-based water price and its effectiveness as a policy tool. The water price model includes a constant component representing the base price and a variable component which is a linear function of the water stress. The water stress feedback is modeled through the demand elasticity of water price. These models are parameterized for six global regions and three water-consuming sectors. Regional distribution of parameters is carried out based on GDP per capita, whereas sectoral distribution is obtained based on literature. The simulation results indicate that incorporating stress-based water price feedback reduces water stress for otherwise high water stress regions like Africa. Since the response to water price changes can reduce water stress, a water stress-based price model can be used as a policy instrument. This model can also capture the systemic progression of the influence of water price rise. The African continent may experience a reduction in food production by about 26% due to rising water prices. Because of the trade-off between regional food production and water stress, cooperation between various regions could help reduce the impact of the impending water crisis. North America and Europe may produce surplus food products and play a pivotal role in alleviating the critical situation in Africa.
Open Access: Yes
Hybrid ML models for volatility prediction in financial risk management
Publication Name: International Review of Economics and Finance
Publication Date: 2025-03-01
Volume: 98
Issue: Unknown
Page Range: Unknown
Description:
Predicting volatility in financial markets is an important task with practical uses in decision-making, regulation, and academic research. This study focuses on forecasting realized volatility in stock indices using advanced machine learning techniques. We examine three key indices: the Shanghai Stock Exchange Composite (SSE), Infosys (INFY), and the National Stock Exchange Index (NIFTY). To achieve this, we propose a hybrid model that combines optimized Variational Mode Decomposition (VMD) with deep learning methods like Artificial Neural Networks (ANN), Long Short-Term Memory (LSTM), and Gated Recurrent Units (GRU). Using data from 2015 to 2022, we analyse how well these models predict volatility. Our findings reveal distinct patterns: the SSE shows high unpredictability, INFY is prone to extreme positive volatility, and NIFTY is relatively moderate. Among the models tested, the Q-VMD-ANN-LSTM-GRU hybrid model consistently performs best, providing highly accurate predictions for all three indices. This model has practical benefits for financial institutions. It improves risk management, supports investment decisions, and provides real-time insights for traders and risk managers. Additionally, it can enhance stress testing and inspire innovative trading strategies. Overall, our study highlights the potential of advanced machine learning, especially hybrid models, to address financial market complexities and improve risk management practices.
Open Access: Yes
