Search in Publications

Found 6278 publications

Real-time and parallel quality control processing on industrial production lines

N. Varjasi

Publication Name: Pollack Periodica

Publication Date: 2008-12-01

Volume: 3

Issue: 3

Page Range: 105-111

Description:

The subject of the article is the evaluation of three acoustical algorithms on industrial production lines. The algorithm is used for the inspection of work-pieces in a noisy industrial environment. High efficiency performance requirements restricted running time and expected precise results make these inspections problematic. A sequential and two parallel algorithms and processing methods for these measurements were developed. These algorithms are real-time and multi-channel processing methods on industrial production lines. They carry out series of precision measurements in the time frame available. After the inspection the quality class and usability of the pieces are determined. These computer-aided inspections are more effective than human measurements because they are more precise, can be repeated multiple times, even with different quality requirements. They are usable on high-speed industrial production lines to obtain results in digital format. © 2008 Akadémiai Kiadó.

Open Access: Yes

DOI: 10.1556/Pollack.3.2008.3.9

Drop performance of dangerous goods packages in the aspect of parcel delivery standards

Ákos Mojzes Kata Vöröskoi Thomas Trost

Publication Name: 21st Iapri World Conference on Packaging 2018 Packaging Driving A Sustainable Future

Publication Date: 2019-01-01

Volume: Unknown

Issue: Unknown

Page Range: 569-577

Description:

Requirements for dangerous goods packaging are well known, whatever version are used. The testing circumstances are strictly defined for each transportation method (road, rail, air, sea). But nowadays it is becoming a practice that courier express operators transport dangerous goods as single package. This parcel delivery method means a higher risk for all kind of logistics participants. By this service the packages are delivered fast, but handled more roughly than in comparison to LTL (less than truckload) or FTL (full truck load). Naturally, the parcel delivery sector uses its own suitability testing methods, which are also well defined. These procedures are coming from various standards such as ASTM, ISTA or corporate (FedEx) standards. This paper compares the most common parcel delivery testing conditions concerning the drop test requirements of DGR (Dangerous Goods Regulation) using packaging such as paper bag, corrugated fibreboard box, steel drum and plastic jerrycan, respectively. Then the test results were analyzed to present the differences.

Open Access: Yes

DOI: DOI not available

Nonlinear simulation of a nondestructive testing measurement system

Amália Iványi Miklós Kuczmann

Publication Name: Physica B Condensed Matter

Publication Date: 2006-02-01

Volume: 372

Issue: 1-2

Page Range: 373-377

Description:

A nondestructive testing (NDT) equipment has been fabricated. The description of the measurement set-up with some measured crack signals applying a Hall-type sensor, furthermore, the T,Ψ-Ψ potential formulation of the nonlinear eddy current field problem in the time domain can be found in this paper. The hysteresis characteristic of the material has been simulated by the previously developed neural network (NN) based isotropic vector hysteresis model. The nonlinear system of equations has been solved by the fixed-point iteration scheme via the polarization method. Comparisons between the results of the 3D simulations and the measurements are also presented. © 2005 Elsevier B.V. All rights reserved.

Open Access: Yes

DOI: 10.1016/j.physb.2005.10.115

Structural behaviour of built-up I-shaped CFS columns

Ardalan B. Hussein

Publication Name: Scientific Reports

Publication Date: 2024-12-01

Volume: 14

Issue: 1

Page Range: Unknown

Description:

The utilization of cold-formed thin-walled members as structural members has gained significant popularity due to their advantages in fabrication, cost-effectiveness, and transportation convenience. However, the reduced thickness of the used sections poses challenges such as global, local, and distortional member buckling, leading to a decrease in their axial strength. This study focuses on addressing these challenges by connecting the channels together using screws as an alternative to welding, considering the cost, time, and ease of implementation. Conducting finite element analysis on structural columns built-up from cold-formed double C steel channels and subjected to axial loads, this paper verifies the numerical models used against experimental tests known from the literature. A comparison of experimental results with nonlinear FEA and AISI & AS/NZ standards reveals commendable agreement, particularly in predicting the buckling behavior of the built-up I-shaped CFS columns. While the results of the finite element analysis show an overestimation of approximately 3.6% compared to the experimental tests, the AISI and AS/NZS standards demonstrate a conservatism of about 3.0%. Furthermore, the current study investigates the influence of screw spacing on axial strength of built-up cold-formed steel columns. The findings are derived from 175 finite element experiments, evaluating seven different cross-sectional profiles with twelve distinct screw spacings. These spacings correspond to the half-wavelength of local, distortional, and global buckling, divided by values ranging from one to four. The screw spacing determined by half the local buckling half-wavelength along the webs’ centerline resulted in enhancements of 22%, 7%, 13%, and 11% in the critical elastic local, distortional, and global column buckling loads, as well as the nominal axial strength, respectively. These increases were even more pronounced for double-lane fasteners with the same spacing, yielding improvements of 25%, 46%, 17%, and 12%, respectively. For economic considerations, it is advisable to utilize single-lane fasteners with a half-wavelength equal to half the local buckling half-wavelength.

Open Access: Yes

DOI: 10.1038/s41598-024-77455-x

An hybrid training method for B-spline neural networks

Cristiano Cabrita János Botzheim António E. Ruano László T. Kóczy

Publication Name: 2005 IEEE International Workshop on Intelligent Signal Processing Proceedings

Publication Date: 2005-12-01

Volume: Unknown

Issue: Unknown

Page Range: 165-170

Description:

Current and past research has brought up new views related to the optimization of neural networks. For a fixed structure, second order methods are seen as the most promising. From previous works we have shown how second order methods are of easy applicability to a neural network. Namely, we have proved how the Levenberg-Marquard possesses not only better convergence but how it can assure the convergence to a local minima. However, as any gradient-based method, the results obtained depend on the startup point. In this work, a reformulated Evolutionary algorithm - the Bacterial Programming for Levenberg-Marquardt is proposed, as an heuristic which can be used to determine the most suitable starting points, therefore achieving, in most cases, the global optimum. © 2005 IEEE.

Open Access: Yes

DOI: DOI not available

Verification of the Ramberg-Osgood material model in midas GTS NX with the modeling of torsional simple shear tests

Zsolt Szilvágyi Richard P. Ray

Publication Name: Periodica Polytechnica Civil Engineering

Publication Date: 2018-05-22

Volume: 62

Issue: 3

Page Range: Unknown

Description:

This study focuses on the back analysis of a geotechnical laboratory test with nonlinear finite element modeling using the Ramberg-Osgood material model. This model has been used by several authors recently for nonlinear ground response analysis and it has been implemented by Midas into their commercial finite element code Midas GTS NX 2014. The verification of the model for 1D nonlinear site response analysis can be found in the documentation of the software package. In this study, Torsional Simple Shear tests were modeled and a comprehensive study was performed to provide verification of the material model for static torsional loading and axisymmetric conditions.

Open Access: Yes

DOI: 10.3311/PPci.11191

Development of the “Complex Project” course in the transport engineering education

Gábor Horváth Gábor Horváth

Publication Name: International Conference on Higher Education Advances

Publication Date: 2023-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1305-1312

Description:

In the paper we discuss the course history, the basic goals and principles defined at the beginning, and we talk about its methodology. For the “Complex project” course the main parts of the lecturer's job are the detailed preparation of the project tender, the operative support of the students' work, and they also have to perform the mid-semester and end-of-semester evaluations. Continous progress is controlled by milestones laid out throughout the program. The effectiveness of the “Complex project” can be determined based on the previous years, and the future possibilities will also be examined. Besides elevating the level of education from the students' perspective, at the same time it also improves the lecturers' competences.

Open Access: Yes

DOI: 10.4995/HEAd23.2023.16223

Using natural deep eutectic solvents for the extraction of antioxidant compounds from cornelian cherry (Cornus mas L.) fruits

E. Lakatos Székelyhidi Rita Beatrix Sik Zsolt Ajtony

Publication Name: Green Analytical Chemistry

Publication Date: 2024-12-01

Volume: 11

Issue: Unknown

Page Range: Unknown

Description:

Traditionally used extraction methods are usually based on toxic and/or flammable solvents. Therefore, currently, increased attention has been focused on environmentally friendly green extraction techniques. We aimed to develop a green extraction procedure by using natural deep eutectic solvents (NADES) to recover antioxidant compounds from cornelian cherry fruits (Cornus mas L.). Natural deep eutectic systems combined with maceration with shaking extraction were tested to recover of antioxidant compounds from cornelian cherry fruits. In this study, four different independent variables, namely solvent type (Glu-CA; Glu-Gly; LA-Glu), water concentration (30, 50, and 70 %; v/v), extraction time (30, 60, 90, and 120 min), and extraction temperature (25, 40, and 50 °C) were investigated. Glucose-glycerin (Glu-Gly; 1:1 M ratio) based solvent provided the best results. In addition, one-factor-at-a-time (OFAT) optimization showed that a temperature of 25 °C, 120 min of extraction time, and water concentration of 50 % (v/v) to be the best extraction parameters for Glu-Gly based NADES extraction. The developed method has been successfully applied for the extraction of antioxidant compounds from 13 different cornelian cherry cultivars. NADES can be used safely to extract phenolic compounds from cornelian cherry fruits compared to conventional extraction solvents (water and 80 % (v/v) ethanol).

Open Access: Yes

DOI: 10.1016/j.greeac.2024.100154

Simulations of poroelastic materials in a complex acoustic system using frequency-dependent parameters in the mid-frequency range

Dániel Feszty Janos Kun

Publication Name: Proceedings of Inter Noise 2021 2021 International Congress and Exposition of Noise Control Engineering

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Efficiency requirements prompt manufacturers to develop ever lighter acoustic packages in vehicles. Poroelastic materials are essential to achieve the desired interior noise level targets and thus the simulation of their effects is of utmost importance in NVH analyses. However, it is challenging to achieve good validation between finite element method (FEM) based simulation results and measurements in the mid-frequency range (400-1000 Hz). One possible reason could be the lack of using frequency-dependent Biot-paremeters describing the poroelastic materials (PEM) characteristics of trims. The present research aims to employ frequency-dependent Biot-parameters for the PEM materials to investigate the acoustic response of a scaled car-like steel structure composed of flat plates and U-section stiffeners enclosing an air cavity. Porous acoustic material is applied to the walls of the cavity. The focus of the study is to understand the effect of applying frequency-dependent Young's modulus and damping values for the PEM parameters in the 100-1000 Hz range. Simulation results obtained from ESI VPS FEM solver are compared with measurements, with particular focus on the interior sound pressure levels. The simulation methodology, including discretization techniques, structural damping and fluid damping applications are described in detail.

Open Access: Yes

DOI: 10.3397/IN-2021-2869