Search in Publications

Found 6278 publications

Data-driven linear parameter-varying modelling of the steering dynamics of an autonomous car

Gabor Rodonyi R. Toth Péter Korös Dániel Pup Ádám Kisari Zsombor Vigh József Bokor

Publication Name: IFAC Papersonline

Publication Date: 2021-07-01

Volume: 54

Issue: 8

Page Range: 20-26

Description:

Developing automatic driving solutions and driver support systems requires accurate vehicle specific models to describe and predict the associated motion dynamics of the vehicle. Despite of the mature understanding of ideal vehicle dynamics, which are inherently nonlinear, modern cars are equipped with a wide array of digital and mechatronic components that are difficult to model. Furthermore, due to manufacturing, each car has its personal motion characteristics which change over time. Hence, it is important to develop data-driven modelling methods that are capable to capture from data all relevant aspects of vehicle dynamics in a model that is directly utilisable for control. In this paper, we show how Linear Parameter-Varying (LPV) modelling and system identification can be applied to reliably capture personalised model of the steering system of an autonomous car based on measured data. Compared to other nonlinear identification techniques, the obtained LPV model is directly utilisable for powerful controller synthesis methods of the LPV framework.

Open Access: Yes

DOI: 10.1016/j.ifacol.2021.08.575

Session recommendation via recurrent neural networks over fisher embedding vectors

Bálint Daróczy Frederick Ayala-Gómez Domokos Kelen Anna Ország András Benczúr

Publication Name: Sensors Switzerland

Publication Date: 2019-08-02

Volume: 19

Issue: 16

Page Range: Unknown

Description:

Recommendation services bear great importance in e-commerce, shopping, tourism, and social media, as they aid the user in navigating through the items that are most relevant to their needs. In order to build recommender systems, organizations log the item consumption in their user sessions by using different sensors. For instance, Web sites use Web data loggers, museums and shopping centers rely on user in-door positioning systems to register user movement, and Location-Based Social Networks use Global Positioning System for out-door user tracking. Most organizations do not have a detailed history of previous activities or purchases by the user. Hence, in most cases recommenders propose items that are similar to the most recent ones viewed in the current user session. The corresponding task is called session based, and when only the last item is considered, it is referred to as item-to-item recommendation. A natural way of building next-item recommendations relies on item-to-item similarities and item-to-item transitions in the form of “people who viewed this, also viewed” lists. Such methods, however, depend on local information for the given item pairs, which can result in unstable results for items with short transaction history, especially in connection with the cold-start items that recently appeared and had no time yet to accumulate a sufficient number of transactions. In this paper, we give new algorithms by defining a global probabilistic similarity model of all the items based on Random Fields. We give a generative model for the item interactions based on arbitrary distance measures over the items, including explicit, implicit ratings and external metadata to estimate and predict item-to-item transition probabilities. We exploit our new model in two different item similarity algorithms, as well as a feature representation in a recurrent neural network based recommender. Our experiments on various publicly available data sets show that our new model outperforms simple similarity baseline methods and combines well with recent item-to-item and deep learning recommenders under several different performance metrics.

Open Access: Yes

DOI: 10.3390/s19163498

Investigation of FDM-Based 3D Printing for Optimized Tooling in Automotive and Electronics Sheet Metal Cutting

Szabolcs Fischer Szabolcs Szalai Mykola Sysyn Dmytro Kurhan Brigitta Fruzsina Szívós Vivien Nemes György Szabó

Publication Name: Applied Sciences Switzerland

Publication Date: 2025-01-01

Volume: 15

Issue: 1

Page Range: Unknown

Description:

Within the scope of the work, the possible use of fused deposition modeling (FDM) technology in executing rapid prototypes of cutting tools for aluminum sheets was systematically studied. Relevant investigations have thus far mainly concentrated on tools for the 3D printing of bent and deep-drawn pieces, yet the implementation of FDM tools in cutting has been insufficiently covered. This study aims to determine the characteristics of FDM cutting tools, such as wear and tear, dimensional stability, and cutting efficiency. Various tool designs were tested under different wall thicknesses and orientations with respect to the feed of Al99.5 sheets with thicknesses of 0.22 mm and 0.3 mm. According to the results, in the best case, three-dimensional printed PLA tools performed six cuts with no burrs and an acceptable wear level due to the IT tolerances (IT9 and IT10). Tools with thicker walls and more appropriate orientations were found to be more robust. However, some designs failed when subjected to greater loads, revealing a deficiency in some of the strength properties of the material. These observations suggest that it is possible to create 3D printed tools for modeling and small-scale production at considerably cheaper and faster rates than conventional methods. Future work will integrate advanced materials and designs to enhance tool performance, further solidifying FDM as a transformative approach in industrial tool manufacturing. With this research, the authors wanted to demonstrate that FDM technology can also be used to produce a classic sheet cut, which, of course, is still of great importance for prototyping or setting up production processes. This research demonstrated that FDM printing can play a role in this area.

Open Access: Yes

DOI: 10.3390/app15010442

Territorial differences between countries with regard to the wellness lifestyle of their youth

Zsuzsa Ivancsóné Horváth Erzsébet Printz-Markó

Publication Name: Forum Scientiae Oeconomia

Publication Date: 2018-01-01

Volume: 6

Issue: 3

Page Range: 101-117

Description:

The focus of the present research is the issue of education on healthy lifestyles and consequently the future target group of wellness tourism. We examined European college students to discern whether there are territorial differences in the wellness lifestyle of their young people and which major characteristics are typical of Hungarian youth. As the result of our literary and questionnaire research, based on factor analysis, we fine-tuned the factors determining the wellness lifestyle in our so-called wellness roulette and make recommendations for lifelong learning in terms of healthy lifestyles.

Open Access: Yes

DOI: 10.23762/FSO_VOL6_NO3_7

Leveraging the Internet of Things and blockchain technology in Supply Chain Management

Horst Treiblmaier John G. Keogh Abderahman Rejeb

Publication Name: Future Internet

Publication Date: 2019-07-01

Volume: 11

Issue: 7

Page Range: Unknown

Description:

Modern supply chains have evolved into highly complex value networks and turned into a vital source of competitive advantage. However, it has become increasingly challenging to verify the source of raw materials and maintain visibility of products and merchandise while they are moving through the value chain network. The application of the Internet of Things (IoT) can help companies to observe, track, and monitor products, activities, and processes within their respective value chain networks. Other applications of IoT include product monitoring to optimize operations in warehousing, manufacturing, and transportation. In combination with IoT, Blockchain technology can enable a broad range of different application scenarios to enhance value chain transparency and to increase B2B trust. When combined, IoT and Blockchain technology have the potential to increase the effectiveness and efficiency of modern supply chains. The contribution of this paper is twofold. First, we illustrate how the deployment of Blockchain technology in combination with IoT infrastructure can streamline and benefit modern supply chains and enhance value chain networks. Second, we derive six research propositions outlining how Blockchain technology can impact key features of the IoT (i.e., scalability, security, immutability and auditing, information flows, traceability and interoperability, quality) and thus lay the foundation for future research projects.

Open Access: Yes

DOI: 10.3390/fi11070161

Rapid, Matrix-Dependent Changes in Polyphenols and Antioxidant Capacity of Methanol Plant Extracts During Short-Term Storage: Implications for Analytical Timing

Tarek Alshaal Attila Kiss

Publication Name: International Journal of Molecular Sciences

Publication Date: 2026-05-01

Volume: 27

Issue: 9

Page Range: Unknown

Description:

Throughout this study, the short-term stability of methanol extracts was evaluated in cases of 15 distinctive, antioxidant-rich plant materials over 3, 7, and 14 days under refrigeration (4 °C), dark room-temperature, and light-exposed room-temperature conditions. A great variability in the matrix-dependent stability of the antioxidants, as well as the pronounced impact of the implied storage conditions on their plausible degradation, was revealed and featured. Initial total polyphenol content (TPC) ranged from 50.50 ± 0.44 mg gallic acid (GAE)/g DW (rosemary) to only 0.02 ± 0.006 mg GAE/g DW (amaranth). After 14 days, pigment-rich vegetable extracts (basil, beetroot powder, spinach powder, dried onion, tomato powder, and yarrow tail) lost 86.2–89.2% of TPC and 80–99% of DPPH (2,2-diphenyl-1-picrylhydrazyl) activity across all conditions, even under refrigeration. In contrast, for Lamiaceae species, markedly higher levels of the referred parameters were to be observed after 14-day-long storage. Decrease in TPC values was found to be 43.7% (rosemary), 50.6% (thyme), and 42.9% (oregano), respectively, while DPPH values were reduced by only 17–29%. Turmeric and walnut flour showed intermediate stability. Refrigeration consistently minimized the degradation of antioxidants (e.g., rosemary’s decrease in DPPH was only 20.3% at 4 °C vs. >70% under ambient conditions), while light exposure significantly accelerated losses of antioxidants in nearly all samples. Methanol extracts of many dietary plants, particularly pigment-rich ones, exhibit rapid and pronounced changes during short-term storage. Comparison with values obtained immediately after extraction shows that even brief storage can lead to substantial deviations. Although the current sampling intervals do not capture changes within the first hours, the results clearly indicate the need to minimize delays and standardize analytical timing to avoid underestimating phenolic content and antioxidant capacity. Moreover, these findings demonstrate that measured antioxidant properties are not solely inherent to the plant material but are strongly influenced by the extract matrix and methodological conditions. Consequently, antioxidant data should be regarded as matrix- and protocol-dependent, with important implications for their interpretation, comparability, and reproducibility across studies.

Open Access: Yes

DOI: 10.3390/ijms27093723

Case study on the tactical level of an autonomous vehicle control

Claudiu Pozna Csaba Antonya Ernö Horváth

Publication Name: International Conference on Electrical Computer Communications and Mechatronics Engineering Iceccme 2021

Publication Date: 2021-10-07

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In this paper, a case study is presented on the tactical level of autonomous vehicle control. Inspired by the human driver behavior, vehicle control is structured in a hierarchy on three levels: the strategic, the tactical, and the operational level. These are connected by specific links, and based on prior information and models, are transforming the input data from the environment into actuator commands on the various degree of freedom of the vehicle. The case study is presenting a simulation of a scenario, detailing the vehicle models with sensors, the collection of behavior, and the behavior selector.

Open Access: Yes

DOI: 10.1109/ICECCME52200.2021.9590868

The 4th Global Conference on Parliamentary Studies: Current Scientific Discourses on Parliaments in a Digital Age

Péter Smuk Áron Ősze

Publication Name: International Journal of Parliamentary Studies

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

This report intends to summarize the academic discussions on actual parliamentary issues at the conference that took place in Athens, 13 June 2025.

Open Access: Yes

DOI: 10.1163/26668912-bja10115

Faunistic and taxonomic data on arboreal oribatid mites (Acari, Oribatida) from Can Gio Biosphere Reserve, Vietnam

Sergey G. Ermilov Jenő Kontschán V. M. Salavatulin

Publication Name: International Journal of Acarology

Publication Date: 2025-01-01

Volume: 51

Issue: 7-8

Page Range: 530-537

Description:

Eleven species of oribatid mites, belonging to eight genera and seven families, were collected from mangrove trees in the Can Gio Biosphere Reserve, Vietnam. One new species–Cultrobates gioensissp. nov. (Ceratokalummidae)–is described. It differs from all representatives of the genus by the presence of monodactylous legs. A supplementary description of Malaconothrus canopeus (Iglesias, Palacios-Vargas and Mahunka, 2001) (Malaconothridae) is presented, based on Vietnamese materials, along with summarized diagnostic morphological traits. https://zoobank.org/lsid:zoobank.org:pub:5F01722A-71BF-4ED8-9D74-89F2F517A521.

Open Access: Yes

DOI: 10.1080/01647954.2025.2571119