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Found 6374 publications

Sustainability reporting practices of agricultural and forestry companies in Hungary: a content analysis

Károly Kacz Szabolcs Troján Judit Hegyi Nóra Gombköto Anita Miklósné Varga

Publication Name: Bio Web of Conferences

Publication Date: 2024-08-23

Volume: 125

Issue: Unknown

Page Range: Unknown

Description:

To demonstrate the sustainability of companies, some companies have already produced sustainability reports, most of which have been published on their websites, while others have only produced and made public the reports and certifications required by law. In the European Union, legislation as of 2014 required the preparation of non-financial reports for publicly relevant entities, companies and parent companies of large groups of companies considered to be entities and having an average number of employees of more than 500. However, in line with the European Green Deal and the Taxonomy Regulation, as of 2023, a new law has been introduced, which extends the sustainability reporting obligation to nonpublic large companies and public small and medium-sized enterprises. Agricultural enterprises should also be prepared for this reporting obligation. This study aims to examine the ESG indices of the sampled companies and seek a correlation between the quality of the information disclosed and the financial characteristics of the companies. The results show that while forestry companies pay more attention to the disclosure of this type of information, there is some under-disclosure in both sectors.

Open Access: Yes

DOI: 10.1051/bioconf/202412501010

Battery deformation measurement with DIC technique

I. Lakatos Szabolcs Szalai Szabolcs Kocsis Szurke

Publication Name: 2020 21st International Symposium on Electrical Apparatus and Technologies Siela 2020 Proceedings

Publication Date: 2020-06-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In this paper the deformation of lithium polymer batteries during charging and discharging is measured using a GOM Atos system. The aim of the study is to evaluate the deformation of the cell surface. During the tests, the battery cell is re-digitized after 10% energy input and output. Trend results are recorded and analysed for deformation as a function of charge level. We also determine open circuit voltage and average deformation point relationship. Our study supports that there is a correlation between the deformation data and the charge level.

Open Access: Yes

DOI: 10.1109/SIELA49118.2020.9167109

Data-driven terminal voltage prediction of li-ion batteries under dynamic loads

Adrienn Dineva Szabolcs Kocsis Szurke Istvan Vajda

Publication Name: 2020 21st International Symposium on Electrical Apparatus and Technologies Siela 2020 Proceedings

Publication Date: 2020-06-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Extensive investigation and prediction of the effects of dynamic battery loading is key to on-board Battery Management Systems (BMS) of Electric Vehicles (EVs) in order to ensure reliable operation and efficient energy management. In this paper, measurements of WLTP discharge tests at different temperatures are conducted on a Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) cell. Terminal voltage, discharge rate and temperatures at four points are taken into consideration. After, historical measurement data is used to build ensemble of boosted tree models and then predict cell voltage outcome sequence into the future. The efficiency of the performance is compared in case of various measurement sets. The results support the efficiency and applicability of direct multi-step-ahead forecasting strategy with standard Machine Learning techniques in battery SoC prediction.

Open Access: Yes

DOI: 10.1109/SIELA49118.2020.9167039

Hydrologic modeling of the loess bluff in dunaujvaros, Hungary

Katalin Bene Gergo Murinkó

Publication Name: Pollack Periodica

Publication Date: 2017-01-01

Volume: 12

Issue: 1

Page Range: 3-15

Description:

The western shoreline of the Danube from Érd to Mohács consists of loess bluffs up to 50 m high. These bluffs can be susceptible to landslides when groundwater conditions weaken the supporting loess. Often this will occur during periods of high rainfall, however morphological, geological and other factors are also important in triggering these movements. Changes in pore water pressures related to precipitation, confined water levels driven by remote catchments, and river level fluctuations are widely recognized as important factors controlling the loess bank stability. This work aims to determine the interaction of rainfall, river level, drainage and local pumping on the pore pressure regime and stability of the bluffs. As a first step, a realistic 2-dimensional infiltration and groundwater model was built that reflects the influence of river levels, rainfall patterns, and local pumping. Based on model results, initial and boundary conditions have a strong influence on seasonal pore pressures. Further study will better define those influences on slope stability along the bluffs.

Open Access: Yes

DOI: 10.1556/606.2017.12.1.1

Enhanced injection molding simulation of advanced injection molds

Norbert Krisztián Kovács András Suplicz József Gábor Kovács Tamás Tábi Béla Zink István Hatos Hajnalka Hargitai Ferenc Szabó

Publication Name: Polymers

Publication Date: 2017-01-01

Volume: 9

Issue: 2

Page Range: Unknown

Description:

The most time-consuming phase of the injection molding cycle is cooling. Cooling efficiency can be enhanced with the application of conformal cooling systems or high thermal conductivity copper molds. The conformal cooling channels are placed along the geometry of the injection-molded product, and thus they can extract more heat and heat removal is more uniform than in the case of conventional cooling systems. In the case of copper mold inserts, cooling channels are made by drilling and heat removal is facilitated by the high thermal conductivity coefficient of copper, which is several times that of steel. Designing optimal cooling systems is a complex process; a proper design requires injection molding simulations, but the accuracy of calculations depends on how precise the input parameters and boundary conditions are. In this study, three cooling circuit designs and three mold materials (Ampcoloy 940, 1.2311 (P20) steel, and MS1 steel) were used and compared using numerical methods. The effect of different mold designs and materials on cooling efficiency were examined using calculated and measured results. The simulation model was adjusted to the measurement results by considering the joint gap between the mold inserts.

Open Access: Yes

DOI: 10.3390/polym9020077

Review of DC Motor Modeling and Linear Control: Theory with Laboratory Tests

Miklós Kuczmann

Publication Name: Electronics Switzerland

Publication Date: 2024-06-01

Volume: 13

Issue: 11

Page Range: Unknown

Description:

This review paper introduces the modeling, measurement, identification and control of direct current motors based on the state space modeling and the transfer function representation. These models are identified by real laboratory measurements, and the simulated results are compared with the measurements. Continuous-time and discrete-time PID (Proportional-Integral-Derivative) controllers, discrete-time state feedback and linear quadratic controllers are designed mathematically. The designed controllers are realized by the microcontroller Arduino UNO, and the behavior of the controllers is compared and analyzed. The noisy current signal has been measured by a discrete-time observer, steady-state Kalman filtering is also studied. The practical results of the implemented controllers support the theoretical results very well.

Open Access: Yes

DOI: 10.3390/electronics13112225

Conventional and nonconventional extraction techniques for optimal extraction processes of rosmarinic acid from six Lamiaceae plants as determined by HPLC-DAD measurement

E. Lakatos V. Kapcsándi Beatrix Sik Zsolt Ajtony

Publication Name: Journal of Pharmaceutical and Biomedical Analysis

Publication Date: 2020-05-30

Volume: 184

Issue: Unknown

Page Range: Unknown

Description:

The goal of this study was to improve the extraction efficiency of rosmarinic acid (RA) from Lamiaceae herbs (lemon balm, peppermint, oregano, rosemary, sage, and thyme) using various extraction techniques (maceration with stirring, MACS; heat reflux, HRE; and microwave-assisted extraction, MAE) and extraction conditions (solvent acidity, solvent type, extraction time and temperature). The RA content was measured by high-performance liquid chromatography with diode-array detection (HPLC-DAD) under test conditions. Our results showed that extraction with acidified aqueous ethanol (EtOH-H2O-HCl, 70:29:1, v/v/v) was the best choice for the recovery of RA compared to other solvent systems. Further study suggested the following optimal extraction times for the different techniques: 120 min at 25 °C with MACS, 15 min at boiling point with HRE, and 5 min at 50 °C and 80 °C with MAE. Based on our results, we demonstrated that by careful adjustment of the extraction conditions, it is possible to set up a single extraction protocol to extract RA from different plants.

Open Access: Yes

DOI: 10.1016/j.jpba.2020.113173

Testing Embedded Software Functionality Of Safety Critical Brake-By-Wire Systems Based On Vector Toolchain

János Májer Szilard Stadinger Akos Krabacz Denes Fodor

Publication Name: Proceedings of the 2024 25th International Carpathian Control Conference Iccc 2024

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Brake-by-wire is an innovative braking system that replaces the traditional hydraulic braking system with an electronic-hydraulic one. The brake-by-wire system is a safety-critical system that requires reliable and efficient communication between the electronic control units (ECUs) in the vehicle. Testing the communication network is critical to ensure the system's safety, reliability, and performance. Vector toolchain provides an efficient and reliable platform for testing the communication network of brake system ECUs. In this research, we present a testing methodology for ECUs in the Vector toolchain environment using Hardware-In-the-Loop (HIL) simulation. The proposed methodology includes the design of test scenarios, the implementation of the test cases, and the analysis of the test results. The results of the research show that the proposed methodology can effectively test the communication network of brake-by-wire ECUs in the Vector toolchain environment and provide insights into the network's performance and reliability.

Open Access: Yes

DOI: 10.1109/ICCC62069.2024.10569260

Analyzing the impact of geographical diversification on portfolio performance

Gergő Thalmeiner László Pataki Attila Bányai Tatay Tibor

Publication Name: Teruleti Statisztika

Publication Date: 2025-01-01

Volume: 15

Issue: 2

Page Range: 321-340

Description:

The portfolio theory, which originated in the 1950s, pointed out that portfolio diversification allows investors to reduce risk. However, in addition to sector diversification, geographical diversification has been considerably less emphasized in equity investment evaluation. Our study contributes to this area. The calculations were conducted over two periods: 2008–2013 and 2014–2019. We constructed our portfolio using only exchange-traded funds (ETFs). We created two portfolios: one geographically diversified and the other focused exclusively on European markets. The geographically diversified portfolio comprised the IEV (iShares Europe ETF), EWH (iShares MSCI Hong Kong ETF), and EWZ (iShares MSCI Brazil ETF) portfolios. For our analysis, we used an approach based on the Monte Carlo simulation. The simulation calculated the Sharpe ratio of the portfolios, annualizing the metrics using the 252 trading day approach. We performed 10,000 iterations to ensure the robustness and reliability of our model. In the first period (2008–2013), we found that the geographically diversified portfolio showed higher volatility and generally lower risk-adjusted returns than the non-geographically diversified portfolio focused on Europe. Conversely, in the second period (2014–2019), the geographically diversified portfolio outperformed the non-geographically diversified portfolio in terms of risk-adjusted returns, suggesting that geographic diversification is preferable in certain market environments, particularly during periods of economic growth. In conclusion, investors should explore the potential of geographic diversification.

Open Access: Yes

DOI: 10.15196/RS150206