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Found 6374 publications

Implementation of a basic flow model in traffic controlling

No authors available

Publication Name: 9th International Symposium of Hungarian Researchers on Computational Intelligence and Informatics, CINTI 2008

Publication Date: 2008-12-01

Volume:

Issue:

Page Range: 523-530

Description:

The contribution introduces a basic model, a manner, how to control - using the specific tools - A crossing of a highway and a lower volume road, while we stop the highway's traffic only in a critical case otherwise just slow it down.

Open Access: No

DOI: DOI not available

Evaluation of acoustic frequency methods for the prediction of propeller noise

Dániel Feszty Mark T. Kotwicz Herniczek Jong Park Sid Ali Meslioui Fred Nitzsche

Publication Name: AIAA Journal

Publication Date: 2019-01-01

Volume: 57

Issue: 6

Page Range: 2465-2478

Description:

The accuracy of several computationally inexpensive acoustic frequency methods is evaluated across a range of propeller geometries and operational conditions. The acoustic models considered predict both near-field and far-field harmonic noise. The implemented models approximate or ignore chordwise noncompactness such that they do not require chordwise aerodynamic data, and therefore do not need to be coupled to a panel or grid-based aerodynamic solver. Each implemented method is compared to 14 test cases originating from nine separate published acoustic experiments. The experimental data considered encapsulate a range of propeller geometries, blade numbers, microphone locations, tip speeds, and forward Mach speeds. The implemented acoustic models demonstrate reasonable agreement with the experimental data, particularly for the prediction of the maximum tonal noise for which Hanson’s model showed the greatest overall accuracy with an average error of 5.9 dB. Using different prediction models based on the freestream velocity reduces the error to 4.7 dB. The presented results suggest that the implemented acoustic methods remain a valuable resource for propeller noise prediction, especially for design and optimization studies, in which a low runtime is important.

Open Access: Yes

DOI: 10.2514/1.J056658

Exploring the Role of Human-Robot Interactions, within the Context of the Effectiveness of a NAO Robot

Eniko Nagy Karl Eva Gyorgy Molnar

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2024-01-01

Volume: 21

Issue: 3

Page Range: 177-190

Description:

The NAO robot has been widely used in various settings, from education and healthcare to entertainment and research. The effectiveness of the robot largely depends on its ability to interact with humans in a meaningful and engaging way. This paper explores the role of human-robot interaction in the effectiveness of the NAO robot. We review the literature on human-robot interaction and highlight the key factors that contribute to successful human-robot interactions. Then we discuss the specific features of the NAO robot that facilitate or hinder effective human-robot interactions. Finally, we present some recent studies that have investigated the impact of human-robot interaction on the effectiveness of the robot in different settings. Overall, our analysis suggests that effective human-robot interaction is essential for the successful implementation of the NAO robot, and that further research is needed to better understand the dynamics of human-robot interaction and its impact on the effectiveness of the robot.

Open Access: Yes

DOI: 10.12700/APH.21.3.2024.3.12

Web-Based Map Service Connected to ROS2 Robot Network

Ferenc Péter Speiser

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 55-60

Description:

The key for testing the driving assistance and autonomous vehicle systems is to establish an advanced infrastructure. For special manoeuvres, a special track is necessary. The path of the track is always changing as the investigated function changes. This means a lot of track construction work for the operation of the proving ground. The engineers of the ZalaZone proving ground perform continuous track construction tasks for the various dynamic tests, which is a time-consuming, resource-intensive task. The goal is to develop an environment that can manage a semi-automatic test track building in a sustainable way. The placing of traffic cones can also be carried out by autonomous robots designed for this purpose, according to pre-designed plans, which are under development at the University of Győr. Automating this task can save a lot of energy, live work, and fuel also can optimize the load and the route of the robots. This paper discusses the theoretical design and possible physical architecture of a framework for the coordination of the tools used. It presents a possible software environment for managing and publishing data in a form that can be integrated with map data represented in different map projection systems. This requires the development of an HTTP-ROS2 interface that can transfer position and other descriptive data of participants communicating on the ROS2 network to the web server that provides the base maps. This work presents a map interface for the near real-time display of positional data from robotic tests carried out in the ZalaZone area. As a result, the map allows the movement of registered objects to be tracked and displayed on the web map via the internet on a publicly accessible server running on the university network. The server is currently capable of mapping the data recorded on the ROS2 network, but only on the local network. It implements the display of pre-saved data from the ROS2 network via the Internet. The long-term goal is to develop a web-accessible mapping framework that allows the current position of the cone-positioning robots to be displayed and controlled through this interface.

Open Access: Yes

DOI: 10.3303/CET23107010

Agricultural by-product filled poly(lactic acid) biocomposites with enhanced biodegradability: The effect of flax seed meal and rapeseed straw

Imre Fekete László Lendvai Tej Singh Sándor K. Jakab

Publication Name: Composites Part C Open Access

Publication Date: 2024-07-01

Volume: 14

Issue: Unknown

Page Range: Unknown

Description:

The purpose of this research was to develop “green” materials by combining poly(lactic acid) (PLA) with two agricultural by-products, namely flax seed meal (FSM) and rapeseed straw (RSS). The natural fillers (0–20 wt.%) were mixed with PLA through extrusion and then injection molded into specimens. The samples were analyzed for their thermal, morphological, mechanical, and physical features and biodegradability. Thermal properties and crystallinity were analyzed using Differential Scanning Calorimetry (DSC), while the morphology was investigated by Scanning Electron Microscopy (SEM). Mechanical properties were characterized through tensile, flexural, and impact measurements, while surface hardness was evaluated by Shore D tests. Water absorption and biodegradability of the samples were also examined. DSC measurements revealed a nucleating effect of both bio-fillers. Based on the tensile tests, major improvement in stiffness was found with the biocomposites having up to ∼16 % higher Young's modulus than neat PLA (2.5 GPa). It came, however, at the cost of tensile strength, which decreased from 56 to 51 MPa even in the presence of the lowest amount (2.5 wt.%) of FSM. Loss in strength was due to the limited adhesion between the components, as also supported by SEM images. The hardness slightly (1–2 %) improved in the presence of even 2.5 wt.% bio-filler and it remained at that level at higher filler loading as well. Laboratory-scale composting revealed that both fillers facilitated biodegradation with FSM being superior. In the presence of 10–20 wt.% FSM, the rate of decomposition was found to be twice as fast compared to neat PLA.

Open Access: Yes

DOI: 10.1016/j.jcomc.2024.100464

Interpolative decisions in the fuzzy signature based image classification for liver CT

Ferenc Lilik Melinda Kovacs Szonja Krisztina Szujo Laszlo T. Koczy Szilvia Nagy

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2021-07-11

Volume: 2021-July

Issue: Unknown

Page Range: Unknown

Description:

In computer aided diagnostics image processing and classification plays an essential role. Image processing experts have been developing solutions for different types of problems, that can be related to image processing, however, due to the sensitivity of the data and the high cost of medical experts, these experimental methods usually have very limited use in real medical practice. The databases that are available are very limited, thus the elsewhere usual and extremely effective convolutional neural network or other automated learning methods are not so easy to adjust for medical image processing. To overcome this difficulty, this paper presents an expert knowledge based method which describes the decision structures by fuzzy signatures. Values of various properties of Computer Tomography images as e.g. density or homogeneity are being considered in these signatures that are different in all case of liver diseases. Because of the low number of samples available, fuzzy sets that describes the leafs of the signatures leads to sparse systems, hence interpolation is needed. However further investigations of other interpolation methods are planned, Stabilized Koczy-Hirota interpolation seems to be appropriate.

Open Access: Yes

DOI: 10.1109/FUZZ45933.2021.9494401

Domestication and proliferation of algae cultures for boosting efficiency of waste-water treatment through symbiosis

László Tolner András J. Kovács Imre Tolner Zsolt Méhes

Publication Name: Periodica Polytechnica Chemical Engineering

Publication Date: 2018-05-16

Volume: 62

Issue: 3

Page Range: 292-298

Description:

Native algae strains have been domesticated and stimulated in activated sludge wastewater treatment operations. The term of domestication indicates that we did not add any selected algae to the wastewater, but made use of species existing in the system. The term of proliferation indicates a stimulation of the biological oxidation process by provision of CO2 with the air stream and illumination of the reactor. The idea of domestication of algae present in communal wastewater systems was demonstrated. Stimulation of the system with domesticated algae community did improve efficiency of the treatment process. Removal of organic components in terms of reduction of chemical and biological oxidation demands (dissolved COD, BOD) as well as nitrogen and phosphorous contents was superior to extent of removal in conventional activated sludge system. We did conclude that conventional systems lack available light and carbon resources for these microorganisms. Upon providing these, symbiotic operation can contribute to reducing greenhouse gas emissions and increase of the rate of pollutants removal kinetics. Symbiotic operation increased the production of biomass expressed in terms of total suspended solids. Biodiesel potential of the filterable biomass was in the range of 8-18%. Because of technical difficulties in manipulation of the excess sludge other than biodiesel synthesis processing scheme has been recommended for economically viable processing.

Open Access: Yes

DOI: 10.3311/PPch.11096

From individual memory to organizational memory (intelligence of organizations)

No authors available

Publication Name: World Academy of Science, Engineering and Technology

Publication Date: 2009-08-01

Volume: 56

Issue:

Page Range: 1-6

Description:

Intensive changes of environment and strong market competition have raised management of information and knowledge to the strategic level of companies. In a knowledge based economy only those organizations are capable of living which have up-to-date, special knowledge and they are able to exploit and develop it. Companies have to know what knowledge they have by taking a survey of organizational knowledge and they have to fix actual and additional knowledge in organizational memory. The question is how to identify, acquire, fix and use knowledge effectively. The paper will show that over and above the tools of information technology supporting acquisition, storage and use of information and organizational learning as well as knowledge coming into being as a result of it, fixing and storage of knowledge in the memory of a company play an important role in the intelligence of organizations and competitiveness of a company.

Open Access: No

DOI: DOI not available

Explaining variability in the production of seed and allergenic pollen by invasive Ambrosia artemisiifolia across Europe

Zita Dorner Huseyin Onen Danijela Stešević Gerhard Karrer Guillaume Fried Paulina Anastasiu Annamária Fenesi Robert Leskovšek Maja Šćepanović Cristina Preda Viktor Tiborcz Caspar A. Hallmann Gergely Zagyvai Bruno Chauvel G. Pinke Eelke Jongejans Mihály Zalai Alla Aleksanyan K. Nagy Andreas Lemke Levani Kalatozishvili Melinda Leitsch-Vitalos Barbara Tokarska-Guzik Gabriella Kazinczi Heinz Müller-Schärer Peter Tóth Suzanne T.E. Lommen

Publication Name: Biological Invasions

Publication Date: 2018-06-01

Volume: 20

Issue: 6

Page Range: 1475-1491

Description:

To better manage invasive populations, it is vital to understand the environmental drivers underlying spatial variation in demographic performance of invasive individuals and populations. The invasive common ragweed, Ambrosia artemisiifolia, has severe adverse effects on agriculture and human health, due to its vast production of seeds and allergenic pollen. Here, we identify the scale and nature of environmental factors driving individual performance of A. artemisiifolia, and assess their relative importance. We studied 39 populations across the European continent, covering different climatic and habitat conditions. We found that plant size is the most important determinant in variation of per-capita seed and pollen production. Using plant volume as a measure of individual performance, we found that the local environment (i.e. the site) is far more influential for plant volume (explaining 25% of all spatial variation) than geographic position (regional level; 8%) or the neighbouring vegetation (at the plot level; 4%). An overall model including environmental factors at all scales performed better (27%), including the weather (bigger plants in warm and wet conditions), soil type (smaller plants on soils with more sand), and highlighting the negative effects of altitude, neighbouring vegetation and bare soil. Pollen and seed densities varied more than 200-fold between sites, with highest estimates in Croatia, Romania and Hungary. Pollen densities were highest on arable fields, while highest seed densities were found along infrastructure, both significantly higher than on ruderal sites. We discuss implications of these findings for the spatial scale of management interventions against A. artemisiifolia.

Open Access: Yes

DOI: 10.1007/s10530-017-1640-9