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Found 6374 publications

Introduction of a Novel Structure for a Light Unmanned Free Balloon’s Payload: A Comprehensive Hybrid Study

Gusztáv Fekete János Jósvai Norbert Hegyi

Publication Name: Sensors

Publication Date: 2024-05-01

Volume: 24

Issue: 10

Page Range: Unknown

Description:

Payloads for light unmanned free balloons must meet several safety requirements such as being able to protect the inner electronics in order to extract scientific data and to reduce the chance of inflicting personal injury in case of an accidental fall. This article proposes a novel payload structure, which exhibits the form of a dodecahedron. The actual form was determined by carrying out theoretical drop tests on different polyhedrons using the finite element method (FEM). From the simulations, it could be deduced that the dodecahedron was the optimal choice, since the duration of the impact was longer, while the impact force was slightly lower. The payload was produced by additive technologies; therefore, after performing tensile tests on probable materials, PLA was selected as the optimal candidate. The theoretical results about the dodecahedron’s ability were validated by laboratory and real-life drop tests, where the new payload was subjected to 56% less impact force under a 78% longer collision time compared to a classic, rectangular cuboid design. Based on these tests, it was demonstrated that the new structure is safer and it is applicable.

Open Access: Yes

DOI: 10.3390/s24103182

Model-based analysis of traffic flow in signalized intersections

Jozsef Homlok Katalin Kovács

Publication Name: Ines 2010 14th International Conference on Intelligent Engineering Systems Proceedings

Publication Date: 2010-07-26

Volume: Unknown

Issue: Unknown

Page Range: 189-194

Description:

Traffic systems are man-made systems in which the human component as a complex factor plays a significant part. [1] The aim of the research was to offer a method which is applicable for setting the real traffic situations at a signalized intersection against the simulated ones, using a traffic model with similar statistical features. The simplest technical apparatus has been used to monitor the real traffic situations. Only one video camera is needed for data collection and it is located in the observable area. Hence time-dependent parameters have been collected which are available for the analysis of the traffic situations. In the case of both traffic models the analysis is based on a behavior model of inhomogeneous driver-populations and an estimation method. The behavior model of inhomogeneous driver-populations handles the time-dependent parameters of driver behavior as the most important predictors, describes the movement and the behavior of the inhomogeneous driver-populations approaching a signalized intersection, passing the amber signal light. The estimation method developed using the model parameters opens the door to estimating the composition of drivers and measuring the capacity of an intersection on a more sensitive scale. © 2010 IEEE.

Open Access: Yes

DOI: 10.1109/INES.2010.5483849

Identification and reconstruction of car body deformation applying tensor product models

No authors available

Publication Name: INES 2006: 10th International Conference on Intelligent Engineering Systems 2006

Publication Date: 2006-12-01

Volume:

Issue:

Page Range: 98-101

Description:

Car body deformation modeling plays a very important role in crash accident analyses, as well as in safe car body design. The determination of the energy absorbed by the deformation and the corresponding Energy Equivalent Speed can be of key importance, however their precise determination is a very difficult task. Although, using the results of crash tests, intelligent and soft methods offer an automatic way to model the crash process itself, as well as to determine the absorbed energy, the before-crash speed of the car, etc. In this paper a modeling technique and an intelligent expert system are introduced which together are able to follow the deformation process of car bodies in car crashes and to analyze the strength of the different parts without any human intervention thus significantly can contribute to the improvement of the modeling, (automatic) design, and safety of car bodies. © 2006 IEEE.

Open Access: No

DOI: DOI not available

Computational Investigation of Fractal-Fractional Nonlinear Viscoelastic Fluids Using Local Radial Basis Function Method

Hijaz Ahmad

Publication Name: Revista Internacional De Metodos Numericos Para Calculo Y Diseno En Ingenieria

Publication Date: 2026-01-01

Volume: 42

Issue: 2

Page Range: Unknown

Description:

Fractal-fractional derivatives generalize both traditional and fractional differentiation approaches by integrating memory effects with fractal properties. This mathematical framework is especially valuable for describing complex systems in which conventional continuum mechanics becomes inadequate, particularly in scenarios involving porous or discontinuous structures. This research investigates the behavior of a non-linear Walter’s-B fluid subjected to time-varying thermal and concentration conditions. Beyond the extended derivative formulation, the analysis incorporates phenomena including first-order chemical reactions, radiative heat transfer, Joule heating, Soret effect, and viscous dissipation. The system is also subjected to a transverse magnetic field with magnitude B0 . The fluid model is initially formulated through traditional constitutive equations and subsequently generalized using a fractal-fractional operator. Solutions to this extended model are computed employing a meshfree numerical approach utilizing localized radial basis functions (LRBF), which eliminates the requirement for structured grids and improves precision when addressing intricate geometries. The computational outcomes, displayed through graphical representations, illustrate how the fractional and fractal parameters influence the rheological characteristics of the Walter’s-B fluid. These findings establish that adjusting these parameters enables retrieval of classical, fractional, and fractal formulations as particular instances within this comprehensive mathematical structure.

Open Access: Yes

DOI: 10.23967/j.rimni.2026.10.75697

Impacts of nuclear energy, greener energy, and economic progress on the load capacity factor: What we learn from the leading nuclear power economies?

Laszlo Vasa Shujaat Abbas Umer Shahzad Wei Teng Md Monirul Islam

Publication Name: Geoscience Frontiers

Publication Date: 2024-05-01

Volume: 15

Issue: 3

Page Range: Unknown

Description:

The worldwide tremor of environmental degradation commonly represents the escalation of emissions levels and ecological footprints that harm the planet's biocapacity. This is because of using gigantic non-renewable energy resources, urbanization stream and massive economic activities in the major industrialized nations. Amid this situation, we investigate the influence of disaggregated energy measures, e.g., renewable, and nuclear energy, income growth and urbanization on the load capacity factor (biocapacity divided by the ecological footprint) of major nuclear power countries, such as France, the USA, Canada, China, and Russia during 1990–2021. To this end, we utilize the CS-ARDL procedure because of the endogeneity, common correlation, non-stationarity in data and heterogeneity in panel units. We contribute to considering the supply side dynamic of environmental degradation parameter, the load capacity, from the perspective of the top nuclear power nations that deviates our analysis from the prevailing scholarly works. However, our findings confirm a significantly positive impact of renewable and nuclear energy on the load capacity factor in improving environmental safety. Besides, economic growth and urbanization negatively affect the load capacity dynamics in spurring environmental degradation. Our findings are robust across an alternative estimation technique, namely the Dumitrescu and Hurlin (DH) causation analysis. Therefore, we recommend formulating pragmatic policies to deter the detrimental effects of income and urbanization by properly utilizing sustainable energy resources to conserve the natural environment.

Open Access: Yes

DOI: 10.1016/j.gsf.2023.101739

Evaluation of fair-faced concrete surfaces using digital image processing

Kitti Karolyfi F. Papp

Publication Name: Fib Symposium

Publication Date: 2018-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1003-1010

Description:

In modem architecture concrete is increasingly used as a design feature as well as for its mechanical properties. Therefore, today’s concrete architecture is characterized by various forms, textures and high surface quality. The exact determination of the surface quality requirements is crucial for being able to substantiate any deficiencies of the completed surface if necessary. According to the German, Austrian and Hungarian standards there are four concrete classes distinguished based on several aspects, such as porosity, discoloration, texture, etc. However, the standardized assessment methodologies for fair-faced concrete surfaces are mainly based on manual methods and several aspects can be evaluated only sub-jectively. The goal of the present study is to propose an objective method for the evaluation of the surface void ratio using photogrammetry and digital image processing techniques. The goal of the whole research is to develop an effective assessment method - taking all aspects into account - with which the overall evaluation and classification of the surfaces can be done automatically from one sampling. This method will lead to a quantitative, objective and therefore more reliable evaluation of the surface-quality of fair-faced concrete elements.

Open Access: Yes

DOI: DOI not available

Investigation of weed vegetation on wet segetal fields in South-Western Hungary

No authors available

Publication Name: Journal of Plant Diseases and Proctectio, Supplement

Publication Date: 2006-12-01

Volume:

Issue: 20

Page Range: 567-576

Description:

Inland water on soils with bad water balance can lead to serious yield losses. Soil management and plant protection is nearly impossible in these marshy vernal pools, wherefore very special vegetation develops. On the basis of 58 phytocoenological surveys made in South-Western Hungary the vegetation of the vernal pools will be characterised. From phytosociological point of view our surveys stand to Ranunculo sardoi-Alopecuretum geniculati and Myosuro-Ranunculetum sardoi associations the nearest, where the proportion of Nanocyperion elements is significant. The following endangered species occure in these vernal pools: Elatine alsinastrum, Limosella aquatica, Lindernia procumbens, Montia fontana, Peplis portula. However vernal pools in segetal fields are causing losses from economical aspects, they can contribute to increase agrobiodiversity and have an important role in maintaining numerous threatened and protected plant species (Red Data List, IUCN, Corine Biotopes Project, Bern Convention). © Eugen Ulmer KG.

Open Access: No

DOI: DOI not available

Fast density reconstruction of Li-BES signal on the COMPASS tokamak

M. Berta J. Seidl P. Háček J. Krbec M. Hron R. Pánek

Publication Name: Review of Scientific Instruments

Publication Date: 2018-11-01

Volume: 89

Issue: 11

Page Range: Unknown

Description:

This article describes a fast and automatic reconstruction of the edge plasma electron density from the radiation of energetic Li atoms of the diagnostic beam on the COMPASS tokamak. Radiation is detected by using a CCD camera and by using an avalanche photo-diode system with a temporal resolution of 20 ms and 2 μs, respectively. Both systems are equipped with a 670.8 nm optical filter which corresponds to the lithium 1s22s1-1s22p1 transition. A theoretical model and a data processing procedure of a raw signal to obtain the density profile are described. The reconstruction algorithm provides the absolutely calibrated electron density profiles together with the measurement error estimated from relatively calibrated light profiles; the implementation is performed in Python. Time demanding operations of the code were optimized to provide reconstruction of a single profile within less than 10 ms which makes the code applicable for processing of a large amount of data. Thanks to this calculation speed, it is possible to reconstruct electron density profiles between two consecutive shots on the COMPASS tokamak with 2 μs time resolution.

Open Access: Yes

DOI: 10.1063/1.5049894

Silt erosion and cavitation impact on hydraulic turbines performance: An in-depth analysis and preventative strategies

Gusztáv Fekete Daeho Lee Robin Thakur Raj Kumar Tanish Kashyap Tej Singh Gia Huy Ngo

Publication Name: Heliyon

Publication Date: 2024-04-30

Volume: 10

Issue: 8

Page Range: Unknown

Description:

The primary issues in the Himalayan Rivers are sediment and cavitation degradation of the hydroelectric power turbine components. During the monsoon season, heavy material is transported by streams in hilly areas like the Himalayas through regular rainfalls, glacial and sub-glacial hydrological activity, and other factors. The severe erosion of hydraulic turbines caused by silt abrasion in these areas requires hydropower facilities to be regularly shut down for maintenance, affecting the plant's overall efficiency. This article provides an in-depth examination of the challenges that can lead to cavitation, silt erosion, and a decrease in the efficiency of various hydroelectric turbines, and it demands attention on the design, manufacture, operation, and maintenance of the turbines. This study's main objective is to critically evaluate earlier theoretical, experimental, and numerical evaluation-based studies (on cavitation and silt erosion) that are provided and addressed throughout the study. As a part of this study, various strategies for mitigating the effects of these problems and elongating the time that turbine may be utilized before they must be replaced have been provided.

Open Access: Yes

DOI: 10.1016/j.heliyon.2024.e28998