Search in Publications
Found 6289 publications
Adjacent-Channel Compatibility Analysis of International Mobile Telecommunications Downlink and Digital Terrestrial Television Broadcasting Reception in the 470–694 MHz Frequency Band Using Monte Carlo Simulation
Publication Name: Electronics Switzerland
Publication Date: 2024-02-01
Volume: 13
Issue: 3
Page Range: Unknown
Description:
This paper delves into the imperative need for coexistence and compatibility in the 470–694 MHz frequency band, as mandated by the World Radiocommunication Conference 2015 (WRC-15) and the WRC-23. It focuses on challenges in the coexistence of Digital Terrestrial Television Broadcasting (DTTB) and International Mobile Telecommunications-2020 (IMT-2020) services in downlink-only mode, particularly in adjacent-channel scenarios. Using Monte Carlo simulations, the study evaluates the probability of interference from IMT base stations with DTTB reception. The analysis thoroughly investigates the impact of the IMT transmitter’s Adjacent Channel Leakage Ratio (ACLR) and the DTTB receiver’s Adjacent-Channel Selectivity (ACS) on the probability of interference. The results demonstrate a significant degradation in the DTTB reception probability at the edge of coverage based on standard assumptions. To address these challenges, this paper provides recommendations for mitigating interference. These include defining enhanced ACLR regulations for IMT base stations, implementing antenna discriminations, providing specialized filters, and establishing national coordination procedures. The research provides valuable insights for informed decision making in spectrum management within the 470–694 MHz band, aiming to facilitate the coexistence of DTTB and IMT-2020 services, in line with international regulations and best practices.
Open Access: Yes
Optimizing structural topology design through consideration of fatigue crack propagation
Publication Name: Computer Methods in Applied Mechanics and Engineering
Publication Date: 2024-02-01
Volume: 419
Issue: Unknown
Page Range: Unknown
Description:
This paper presents an advanced approach for structural topology optimization by incorporating fatigue crack propagation analysis. The extended finite element method (X-FEM) is employed to model initial crack propagation, while the Paris model serves as the basis for simulating fatigue crack growth. The proposed methodology aims to optimize the structural design by minimizing compliance while considering volume and fatigue constraints. The proposed method employs the developed bi-directional evolutionary structural optimization (BESO) algorithm. The accuracy of the proposed technique is validated through the solution of benchmark problem and is further demonstrated in its effectiveness and robustness by examining several numerical examples. The optimization process considers various crack conditions, including the absence of cracks, horizontal and vertical cracks of different lengths. The optimized topologies obtained through the proposed algorithm clearly demonstrate the impact of crack presence, crack direction, and crack length on the material distribution. Furthermore, the convergence histories of the objective function, represented by mean compliance, highlight the influence of crack length on the stiffness and converged compliance of the structure. The results demonstrate its ability to adapt the material distribution based on fatigue cracks propagation conditions and achieve optimal topologies that balance structural integrity and performance.
Open Access: Yes
Measurement of Alternatives and Ranking according to Compromise Solution (MARCOS) Method: A Comprehensive Bibliometric Analysis
Publication Name: Decision Making Applications in Management and Engineering
Publication Date: 2024-01-23
Volume: 7
Issue: 2
Page Range: 313-336
Description:
This paper explores the evolution, applications, and prospective developments of a very popular multi-criteria decision-making (MCDM) method called Measurement of Alternatives and Ranking according to COmpromise Solution Method (MARCOS). Employing an extensive bibliometric analysis, the study examines 115 pertinent papers sourced from the Scopus database spanning over the years from 2020 to 2024. This study also provides an evaluation of the methodological significance and outlines potential future directions of MARCOS method. The outcomes indicate "Sustainable supplier selection in healthcare industries using a new MCDM method: Measurement of alternatives and ranking according to COmpromise solution (MARCOS)" by Stević et al. (2020) as the most cited paper. Journals such as "Sustainability (Switzerland)", "Mathematics" and "Expert Systems with Applications" stand out among the most cited journals. "University of East Sarajevo" is an institution distinguished for its prolific research in this field. "Stević Ž." Has been identified as the most cited and published author. The most frequently used keywords are "MARCOS", "MARCOS method", and "MCDM". CRiteria Importance Through Intercriteria. Correlation (CRITIC) method is a weighting model often integrated with MARCOS method. The results of the study provide researchers and practitioners in the field of MCDM with an important insight into the current state of the MARCOS methodology, highlighted studies and potential future developments. It also provides a comprehensive overview of the importance of this method in the multi-criteria decision-making literature, shedding light on future research directions.
Open Access: Yes
The social cost of ill health among the working-Age population in 2019 in Hungary
Publication Name: Orvosi Hetilap
Publication Date: 2024-01-21
Volume: 165
Issue: 3
Page Range: 110-120
Description:
Introduction: We have quantified the healthy life years lost and the costs incurred in 2019 due to the poor health of the Hungarian population aged 30-64 from a societal perspective, but also from the perspective of several other social actors, calculating the indirect costs according to the human capital approach. Objective: The aim of our estimate is to shed light on the radically high losses that Hungary incurs year after year as a result of its inhabitants living significantly shorter and sicker lives than people in similar situations in other countries. Method: In the first part of the analysis, we aggregated the time lost due to illness and disability for the age group 30-64 in 2019. The aggregated Hungarian values for the studied age group were compared with the corresponding values for the Visegrad countries, Austria and the European Union. The second part of the analysis aggregates the social costs of time spent in ill health. A distinction is made between direct costs, which involve the movement of money, and indirect costs, which are embodied in lost income or production. Results: In Hungary, the nearly 4.8 million people aged 30-64 spent a total of 654,000 years on sick leave in 2019, which equated to an average of about 50 days per person. This means 14% of the total number of working days could have been working days in good health. The direct costs, i.e., the expenditure of the Health Insurance Fund and the expenditure financed by patients and voluntary insurance, amounted to HUF 1,446 billion. Indirect costs, i.e., expenditure due to the loss of working years as a result of premature death and illness, represented a further burden of HUF 2,279 billion. Conclusion: In 2019, the direct and indirect expenditure of people aged 30-64 amounted to HUF 3425 billion, or 7.21% of the GDP. It is well known that in developed countries, including Hungary, the greatest health losses are caused by non-communicable chronic diseases, which can be prevented by a healthy lifestyle. Therefore, the promotion of healthy lifestyles and the creation of a conducive physical and social environment are essential for improving the country s competitiveness.
Open Access: Yes
Carbon conundrums: Geopolitical clashes and market mayhem in the race for sustainability
Publication Name: Journal of Environmental Management
Publication Date: 2024-01-15
Volume: 350
Issue: Unknown
Page Range: Unknown
Description:
This research presents an in-depth investigation into the dynamic correlation between geopolitical conflicts and carbon markets utilizing the Time-Varying Parameter Vector Autoregression (TVP-VAR) technique. The analysis focuses on the interconnectedness between the Geopolitical Risk Index Daily (GPRD) and vital carbon pricing instruments, specifically the Intercontinental Exchange Endex European Union Allowance (ECEFDC), KraneShares California Carbon Allowance Strat ETF (KCCAK), Shanghai Environment and Energy Exchange China Emission Allowances Online Transactions (SAXCEA), and S&P Global Ex-Japan LargeMidCap Carbon Efficient Index (SPGJ). The daily fluctuations were traced from May 2021 to July 2023. The analysis is divided into short- and long-term connectedness, with particular emphasis on the impact of the Russia-Ukraine conflict on the GPRD's spillover on carbon markets. The short-term connectedness (1–5 days) between GPRD and ECEFDC shows variability, fluctuating between 10% and 40%. Conversely, long-term connectedness exhibited a significant increase during the conflict, peaking at approximately 34% by mid-2022. The analysis of the Total Dynamic Connectedness (TCI) between the GPRD and the KCCAK indicates comparable magnitudes, although with minor initial discrepancies. The short-term connectedness of GPRD and KCCAK decreases from its peak of approximately 10% to approximately 1%. Conversely, long-term connectedness varies between approximately 32% and 2% from May 2022 onwards. The long-term connectedness between GPRD and SAXCEA revealed variable patterns, peaking at around 18% at the beginning of the sample period and rapidly reducing to around 1% within two months. The analysis of the connectedness between GPRD and the SPG) identifies intense fluctuations in both TCI and long-term connectedness. After an initial increase and decrease, these patterns rebound and experience another increase. This research provides significant insights into the complex dynamics of geopolitical conflicts and carbon markets, particularly the impact of the Russia-Ukraine conflict on carbon market behavior.
Open Access: Yes
A review on the factors of liner collapse in type IV hydrogen storage vessels
Publication Name: International Journal of Hydrogen Energy
Publication Date: 2024-01-02
Volume: 50
Issue: Unknown
Page Range: 236-253
Description:
The on-board hydrogen storage of mobile applications is a key area of global industrial transformation to hydrogen technology. The research work provides an overview about the principle of hydrogen fuel cell vehicles, with a focus on the widespread on-board hydrogen storage technologies. In this work, type IV composite pressure vessels in particular are reviewed. The key challenges of polymeric liners are deeply investigated, and liner collapse was identified as a critical failure of type IV vessels. Different factors of liner collapse were categorized and relevant material properties - such as permeability, physical characteristics, and surface properties - were explained in more detail to lay the foundation for further research on high barrier, durable polymeric liner materials.
Open Access: Yes
Automatized Driving Data Analyzer: A Synchronized and Modular Application for Data Logging and Analysis †
Publication Name: Engineering Proceedings
Publication Date: 2024-01-01
Volume: 79
Issue: 1
Page Range: Unknown
Description:
The Automated Driving Data Analyzer (ADDA) is a modular application written in Python for the synchronized acquisition and analysis of physiological, vehicle, and interface data. It provides a managed data acquisition process and one-click data analysis. It also provides raw data storage and systematic archiving of data sets. ADDA integrates real-time data from a BeamNG vehicle simulation, Pupil Labs eye-tracking system, hand-tracking, and cardiac data. This integration allows the simultaneous recording and analysis of multiple data streams, which can be visualized and controlled through a graphical user interface (GUI) built with Tkinter. The application is designed to help researchers and engineers analyze driving behavior under different conditions, enabling a deeper understanding of the interactions between the driver and automated driving functions.
Open Access: Yes
