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Found 6423 publications

Hydrogen Policy Environment in the European Union, Current Status of Policy Uptake

András Torma Péter Németh Barna Hanula

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 499-504

Description:

Hydrogen (H2) can become a crucial technology in building an independent and resilient energy infrastructure. The production and utilisation of green hydrogen will play a crucial role in the energy environment of the European Union in the future. Several strategies were defined, and policy actions were taken. H2 has a comparably high lower heating value and no direct harmful emission during use, so it presents a viable alternative for conventional energy carriers. Independently from the final form of usage, H2 will play a key role in integrating green electricity into the grid, as according to the state-of-the-art, large-scale, long-term energy storage is only feasible in molecules containing H2. H2-based mobility solutions could offer a viable technology for sustainable transportation. This article investigates H2 production and demand in the EU, as well as the directives and incentives of the EU to accelerate H2 production and H2 technologies in general. Based on the existing policies and applications, it reviews the up-to-date status of policy uptake within the EU and gives insights into the different preparedness for the transition to a H2-based energy system of the Member States.

Open Access: Yes

DOI: 10.3303/CET23107084

Perspective of Created Value in Consumer Choice: Comparison of Economic and Ecological Dimensions

Jakub Kubiczek Bartłomiej Hadasik Dominika Krawczyńska Kornelia Przedworska Aleksandra Ryczko Erika Zsuzsanna Madarász

Publication Name: Sage Open

Publication Date: 2024-01-01

Volume: 14

Issue: 1

Page Range: Unknown

Description:

This paper aims to identify and categorize the factors influencing consumer goods’ value into ecological and economic dimensions and subsequently compare them. The analysis employs the Allegro Reviews (AR) dataset, comprising post-purchase product reviews, with a focus on a sample of 1,400 randomly selected reviews from a pool of 10,615 comments. Through this examination, distinct influencing factors are identified, categorized as either ecological or economic, and their frequency of reference in online reviews was compared. The research findings show that consumers consistently address economic dimensions in their reviews. Notably, emphasis is placed on goods’ quality, pricing, and the price-quality relationship. On the other hand, ecological aspects receive limited attention in reviews, suggesting their lesser significance to consumers compared to economic considerations. This study’s implications for theory and practice indicate that companies should prioritize economic aspects in their value creation endeavors, relegating ecological factors to a secondary role. However, from a global standpoint, enterprises must incorporate ecological dimensions during the value creation process to avert environmental degradation, which could otherwise undermine overall societal quality of life. In terms of originality and value, this research diverges from typical consumer choice studies that rely on questionnaires. Instead, it analyzes actual post-purchase product reviews, providing insights into tangible elements contributing to goods’ value, thus bypassing reliance on mere declarations. JEL Classification: D11, D12, L25, L26.

Open Access: Yes

DOI: 10.1177/21582440241238516

A Localized Multi-level Method of Fundamental Solutions for Inhomogeneous Problems

Csaba Gáspár

Publication Name: Lecture Notes in Computational Science and Engineering

Publication Date: 2025-01-01

Volume: 153 LNCSE

Issue: Unknown

Page Range: 345-354

Description:

A localization technique is proposed to solve some elliptic problems based on the classical Schwarz overlapping method. The original problem is converted to solving a sequence of subproblems (which are much less than the original problem) resulting in an iterative method. The local problems are solved by the Method of Fundamental Solutions. The localization technique makes it possible to apply the method to inhomogeneous problems and to more general problems as well. The method can be embedded into a natural multi-level context, which significantly improves the computational efficiency. As a further application, the proposed method is applied to the scattered data interpolation problem.

Open Access: Yes

DOI: 10.1007/978-3-031-86173-4_35

Investigation of the performance of direct forecasting strategy using machine learning in State-of-Charge prediction of Li-ion batteries exposed to dynamic loads

Adrienn Dineva Bence Csomós Szabolcs Kocsis Szurke Istvan Vajda

Publication Name: Journal of Energy Storage

Publication Date: 2021-04-01

Volume: 36

Issue: Unknown

Page Range: Unknown

Description:

On account of intense technological advances regarding Electric Vehicles, the state evaluation and prediction issues of Li-ion cells have become increasingly important for ensuring the competitiveness in terms of feasible performance and range. Albeit the wide investigation of various standard modelling and estimation techniques, only limited researches focus on their precision and applicability under heavy transient working conditions. This paper is concerned with Li-ion battery terminal voltage and State-of-Charge (SoC) prediction for two types of dynamic loads. Attention is focused on the investigation of the applicability of direct multi-step forecasting strategy in combination with Machine Learning. Beside that, a feature bank is composed of discharge profiles obtained at different C-rates. The set of discharge curves is proposed to complement the feature extraction, i.e. the additional historical data is considered for model building. Special care is devoted for the design of appropriate training data. Hence, a battery cell model is built for simulating intensive dynamic load scenarios in addition to the experimental setup. The cell model is validated by using measurement data. Results have demonstrated, that in case of WLTP-type discharge load of 0.3C-rate the forecasting performance is highly efficient on measurement data. Under dynamic loads of 1C-rate, or when small historical data is available, the application of feature bank improves the performance. We have obtained comprehensive results proving that the application of direct multi-step forecasting strategy using XGBoost represents a viable alternative to capture real-time the cell dynamics and predict the terminal voltage and SoC of Li-ion batteries exposed to dynamic loads.

Open Access: Yes

DOI: 10.1016/j.est.2021.102351

Hidden content of passenger data in public transport

Balázs Horváth Viktor Nagy

Publication Name: Procedia Computer Science

Publication Date: 2017-01-01

Volume: 109

Issue: Unknown

Page Range: 506-512

Description:

Nowadays, data sets are spreading continually, generated by different devices and systems. In most cases, these data are stored, and the service providers don't use the information they contain, what even more they delete these data to save space. However, these data are processable with the modern devices and methods, and we can use them for obtaining information. This paper presents a possible application of the digital raw materials, taking the public transport passengers boarding and alighting information as a base. Based on these, we are able to deduce the characteristics of the stop point's environment since the different land usage yields dissimilar stop usage with well-defined peak hours. With the help of distance measurement and classification techniques it is possible to define how similar are the stop points to predefined patterns and we can create stop point groups which define separated zones. The paper shows a usage method of distance measurement methods and classification in public transportation and presents the background of this kind of land-use zone distribution technic.

Open Access: Yes

DOI: 10.1016/j.procs.2017.05.320

High-Sensitivity SIW Sensor for Wide-Range Non-Invasive Blood Glucose Monitoring Using Complementary Split-Ring Resonator

Balázs Benyó Katalin Kovács Hussam Al-Saedi Halah I. Khani Ameer B. Alsultani Muntadher M. Hoom Ameer R. Hassan

Publication Name: Applied Biosciences

Publication Date: 2026-03-01

Volume: 5

Issue: 1

Page Range: Unknown

Description:

This work presents a compact microwave sensor for noninvasive blood glucose monitoring based on a substrate-integrated waveguide loaded with a complementary split-ring resonator on RO4350. The sensing principle uses shifts in resonance frequency and changes in S-parameters to track the dielectric dispersion of glucose-containing tissue. The resonator is constructed using Substrate-Integrated Waveguide (SIW) technology, which mimics the propagation characteristics of a conventional rectangular waveguide. To validate its versatility, the sensor implements three practical sample delivery modes: direct liquid contact with the sensing surface, a glass tube holder mounted over the active region, and a non-invasive fingertip interface. Electromagnetic simulations and benchtop measurements confirm clear glucose-dependent frequency shifts with stable matching and insertion levels. Across the physiological range of 20 to 200 mg·dL−1, the sensor exhibits clear glucose-dependent resonance shifts in all configurations. In direct contact mode, the resonance frequency shifts from 10.83 GHz to 10.45 GHz with sensitivities up to 2.47 MHz per mg·dL−1. The tube configuration shows a shift from 10.49 GHz to 10.38 GHz with sensitivity up to 0.80 MHz per mg·dL−1, while reducing contamination. In the non-invasive fingertip mode, the resonance shifts from 2.56 GHz to 2.52 GHz with sensitivities up to 0.25 MHz per mg·dL−1. These results confirm the sensor’s compactness, reliability, and suitability for portable, low-cost glucose monitoring. The results indicate that the proposed sensor can support practical continuous or spot monitoring and offers a clear path toward portable and low-cost glucose assessment.

Open Access: Yes

DOI: 10.3390/applbiosci5010021

Model oriented enterprise integration: Metamodel for realizing the integration

Maria Raffai

Publication Name: IFIP International Federation for Information Processing

Publication Date: 2008-01-16

Volume: 255

Issue: Unknown

Page Range: 807-816

Description:

The main task of IT-specialists in the last decades was to develop applications supporting different business functions and processes. For today the enterprises are well equipped with IT-devices and applications, but in most cases they run separately in various business units and/or on different platforms, they work with data stored not only redundant but also in other forms. Consequently there is an urgent need for integrating systems and fulfilling the entrepreneurs', customers', citizens' needs for on-line inter-organizational cooperation. © 2008 International Federation for Information Processing.

Open Access: Yes

DOI: 10.1007/978-0-387-76312-5_1

Data-Based Assembly Patterns for Overall Equipment Effectiveness at Semi-Automatic Assembly Lines

János Jósvai Péter Dobra

Publication Name: Periodica Polytechnica Mechanical Engineering

Publication Date: 2022-01-01

Volume: 66

Issue: 3

Page Range: 231-236

Description:

In industrial practice, production planning is a key factor for manufacturers and suppliers. The entire planning process spans from the appearance of the customer demand to the fulfillment of the demand. Operational execution is based on pre-planned production processes and operations using properly allocated resources. The accurate planning of assembly operations within production is an extremely complex process in terms of efficiency. Predicting stochastically variable efficiencies is difficult due to the ever-changing manufacturing conditions. This paper defines typical assembly process situations for a semi-automatic assembly line and examines their consequence for the Overall Equipment Effectiveness (OEE). Firstly, a literature review demonstrates the scientific relevance. Secondly, the classification of patterns based on assembly process description parameters is described taking into account the positive and negative effects on the OEE. In addition, the assembly patterns and their characteristics are illustrated through a real automotive example.

Open Access: Yes

DOI: 10.3311/PPme.19910

Study of the Negative Work Area in the p-V Diagram of an HCCI Engine †

Cs Tóth-Nagy

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

Homogeneously charged compression ignition is a promising combustion process that is proven to increase combustion efficiency and decrease exhaust emissions when compared to Otto or Diesel engine efficiencies and emissions. The HCCI process can be considered an advancement on the path to sustainability. However, improper control of the start of combustion causes the efficiency of the engine to drop significantly. The reason for this efficiency drop is that an early start of combustion causes the piston on the upward stroke to experience increased cylinder pressure after the combustion process is complete. The piston must further compress the cylinder content until it reaches the top dead center. During this process, the piston still experiences an increased gas force on the way towards TDC, having to invest extra disadvantageous work into the compression stroke, causing a negative work area in the pressure–volume diagram of the engine. The present study introduces the negative work area in the p-V diagram of an HCCI engine. It describes the phenomenon and explores the reasons behind it. It also investigates some of the factors affecting the negative work area in the p-V diagram.

Open Access: Yes

DOI: 10.3390/engproc2024079022