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Found 6278 publications

Investigation of confinement effect by using the multi-level shear box test

J. Klompmaker Ferenc Horvát

Publication Name: 10th International Conference on Geosynthetics Icg 2014

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The stabilisation and reinforcement of crushed stone aggregate in infrastructural applications using geogrid reinforcement is based on the phenomenon called the "interlocking effect". Through shear interaction of the aggregate with the geogrid, the aggregate is laterally restrained and tensile forces are transmitted from the aggregate to the geogrid. This interaction helps reducing lateral movement of the aggregate and optimises road/track performance. It is well known that this strengthening effect depends on several influencing factors. It is still difficult to quantify the true reinforcement efficiency with regard to the limit of the lateral restraint effect (or confining resistance) over the depth of the aggregate layer being placed on top of the geogrid. To be able to quantify the confining resistance efficiency of geogrids over the depth of the installed aggregate layer a laboratory test was developed (Multi-level shear box test) which allows measuring the shear resistance as a function of the distance from the geogrid layer (in vertical direction). This paper will describe the methodology of the so called "Multi-level shear box test" as well as the results of the confinement efficiency of different type geogrids in combination with railway ballast.

Open Access: Yes

DOI: DOI not available

Time optimal control of four-in-wheel-motors driven electric cars

Gyorgy Max Bela Lantos

Publication Name: Periodica Polytechnica Electrical Engineering and Computer Science

Publication Date: 2014-01-01

Volume: 58

Issue: 4

Page Range: 149-159

Description:

The paper deals with the time optimal control of automatically driven electric cars in a test path under state and input constraints. The problem can be formulated as a dynamic nonlinear optimal control problem (DNOCP). The resulting DNOCP is solved by reformulating it to a static nonlinear program (NLP) using time discretization and direct multiple shooting methods. A novel method is presented to convert the optimal solution obtained using the single-track model to the optimal control of four-in-wheels-motors driven (4WD) cars. The conversion assures similar motion of the COG of both models and optimal distribution of the longitudinal wheel forces. A discrete model predictive control (MPC) is proposed for the linearized 4WD vehicle model under perturbations which uses the distributed wheel forces and optimizes the perturbations with analytically solvable end constraints. The elaborated method can form the basis to generate an offline database of a general collision avoidance system (CAS).

Open Access: Yes

DOI: 10.3311/PPee.7806

Potential formulations for solving TEAM problem 27

Miklós Kuczmann Zoltán Pólik

Publication Name: Przeglad Elektrotechniczny

Publication Date: 2009-12-01

Volume: 85

Issue: 12

Page Range: 137-140

Description:

This paper presents a study of using two potential formulations-the A z.ast;-A formulation, and the T, Φ - Φ formulation-to solve the TEAM problem No. 27 (Eddy Current NDT and Deep Flaws). A procedure to determine arbitrary periodic excitation signal by using Fourier series will also be shown. The numerical results are compared with the experimental waveforms. The goal of this work is to find the more precise and the faster formulation and to approximate the response of a linear electromagnetic system, when the excitation is a periodic signal.

Open Access: Yes

DOI: DOI not available

A robust fingerprint identification approach using a fuzzy system and novel rotation method

Ahmad A. Momani László T. Kóczy

Publication Name: Pattern Recognition

Publication Date: 2025-03-01

Volume: 159

Issue: Unknown

Page Range: Unknown

Description:

Forensic science has developed significantly in the last few decades. Its key role is to provide crime investigators with processed data obtained from the crime scene to achieve more accurate results presented in court. Biometrics has proved its robustness against various critical crimes encountered by forensics experts. Fingerprints are the most important biometric used until now due to their uniqueness and production low cost. The automated fingerprint identification system (AFIS) came into existence in the early 1960s through the cooperation of the countries: USA, UK, France, and Japan. Ever since it started to develop gradually because of the challenges found at the crime scenes such as fingerprints distortions and partial cuts which in turn can severely affect the final calculations made by experts. The vagueness of the results was the main motivation to build a robust fingerprint identification system that introduces new and enhanced methods in its stages to help experts make more accurate decisions. The proposed fingerprint identification system uses Fourier domain analysis for image enhancement, then the system cuts the image around the core point after applying the rotation and core point detection methods. After that, it calculates the similarity based on the distance between fingerprint histograms extracted using the Local Binary Pattern (LBP). The system's last step is to translate the results into a sensible form where it utilizes fuzziness to provide more possibilities for the answer. The proposed identification system showed high efficiency on FVC 2002 and FVC 2000 databases. For instance, the results of applying our system on FVC 2002 provided a set of three ordered matching candidates such that 97.5 % of the results provided the correct candidate as the first order, and the rest of 2.5 % provided the correct candidate as the second order.

Open Access: Yes

DOI: 10.1016/j.patcog.2024.111134

Influence of bionic footwear on lower limb biomechanics across running experience levels: a controlled laboratory study

Yaodong Gu Gusztáv Fekete Dong Sun Xue Li Hairong Chen Zhiyi Zheng Enze Shao Qian Liu Yufei Fang Dongxu Wang Xue Li

Publication Name: Frontiers in Sports and Active Living

Publication Date: 2025-01-01

Volume: 7

Issue: Unknown

Page Range: Unknown

Description:

Introduction: While the biomechanics of lower extremity during running and the impact of conventional running shoes on these traits have been extensively investigated, the influence of bionic shoes on runners remains largely, especially those runners with different experience levels. The aim of this study was to evaluate the biomechanical differences between experienced and novice runners when wearing two distinct types of footwear: bionic shoes and neutral shoes. Methods: Fourteen healthy male heel-strike runners participated and completed the running test wearing two pairs of running shoes respectively. A two-way-repeated-measures analysis of variance was used to determine the effects of participant experience level and shoe type on joint biomechanics. During the stance phase, shoe design primarily influenced the kinematic and dynamic performance of the ankles, knees, and hip joints. Results: When participants wore bionic shoes, there was a significant increase in the range of motion of the ankle and hip joints (p < 0.010), a remarkable increase in knee joint angular velocity (p < 0.010), and a significant decrease in hip joint angular velocity (p < 0.001). Concerning differences in experience levels, experienced runners exhibited significantly higher ankle joint angular velocity (p = 0.005) and knee joint angular velocity (p < 0.010) compared to novice runners, whereas novice runners demonstrated a significantly greater range of knee joint motion than experienced runners (p < 0.050). Conclusion: Our findings preliminarily suggest that experienced runners demonstrate superior performance as well as better stability and motor control of knee joint compared to novice runners who showed smaller knee angular velocity and greater range of motion during running. Furthermore, the increased range of motion of the ankle and hip joints in bionic shoes can activate the relevant muscle groups to a greater extent, which have a certain potential effect on the training performance of runners and the improvement of muscle control ability. While, due to the lack of a certain movement foundation, novice runners may have higher risk of injury.

Open Access: Yes

DOI: 10.3389/fspor.2025.1536629

Investigation of effect of water content on railway granular supplementary layers

Szabolcs Fischer

Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu

Publication Date: 2021-01-01

Volume: 2021

Issue: 3

Page Range: 64-68

Description:

Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different ‘samples’ were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multilevel shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road ‘products’ have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.

Open Access: Yes

DOI: 10.33271/nvngu/2021-3/064

AI Based Plagiarism Checking : Ease of use and appli7cable system for teachers to find similarities in students' assessments

Jozsef Cserko Gyorgy Molnar

Publication Name: Cando EPE 2022 Proceedings IEEE 5th International Conference and Workshop in Obuda on Electrical and Power Engineering

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 187-192

Description:

One of education's most challenging tasks is accurately assessing student performance. Unfortunately, even nowadays, assessment is mainly done manually, with teachers manually correcting submitted work, essays, and dissertations. There is plagiarism checking services and algorithms, but these search for matches in theses and publications on the Internet, so they need to be more suitable for facilitating teachers' daily work. In this paper, we present a self-developed plagiarism screening application that can find duplicates in students' submitted work. The tool performs simple text comparison and syntactic and semantic checking. We also created an easy-to-use online interface where users can easily create and run projects.

Open Access: Yes

DOI: 10.1109/CANDO-EPE57516.2022.10046379

Computational intelligence for gestural communication using emotional model

János Botzheim Bakhtiar Yusuf Toru Yamaguchi Naoyuki Kubota

Publication Name: Iwaciii 2013 3rd International Workshop on Advanced Computational Intelligence and Intelligent Informatics

Publication Date: 2014-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

When conducting natural communication in addition to perform verbal communication, non-verbal communication such as gestural information should also be understood. By the word "understand" we mean not only the recognition of one action, but also grasp the meaning of the gesture itself. Therefore, in order to understand the meaning of an action, in this paper we propose emotional model along with the gesture recognition technique. First we discuss the gesture recognition method using iPhone camera by applying steady state genetic algorithm, spiking neural network and self organizing map. After that we use the gesture recognition result as an input data for the emotional model.

Open Access: Yes

DOI: DOI not available

Social services in the social security system of family support

Ivett Szombati

Publication Name: Orvosi Hetilap

Publication Date: 2019-02-01

Volume: 160

Issue: Unknown

Page Range: 43-48

Description:

Introduction and aim: In my study, analysing the data available from the change of the regime to the present day, from among the social services, I examine the changes of the financial support relating to children and its parts which are currently financed from the budget of the National Health Insurance Fund of Hungary, with special emphasis on the Child Care Benefit and the Child Care Allowance and their modifications. Data and methods: Within the framework of our research, we analyze – through data from the National Health Insurance Fund of Hungary, the Hungarian Central Statistical Office, the Organisation for Economic Co-operation and Development (OECD) and the Hungarian State Treasury as well as on the basis of literature review – the social financial support and its changes, within the family policy system. Results: Hungarian family policy is still driven by the attitude of staying at home for three years with the child. The long period spent at home with the children fundamentally affects the adjustment of mothers to the labour market which has a direct effect on the economic productivity. Even though according to the current regulations, mothers are allowed to work full-time besides receiving child care allowance after their child fills 6 months, part-time employment and telework is still in its infancy compared to the Western-European countries. Based on our research, high percentage of families go for the child care benefit directly after the birth of the child thus not participating in the labour market processes. Besides if they do participate, the percentage of employment on minimal wage is still very high which means that in 2016–2017 36% of families with two breadwinners and two children were forced to survive on subsistence income. Conclusion: In the examined period, we found that social and family policy changes unfortunately were not able to react sufficiently to the demographic challenges despite Hungary spending significantly more on family policy than other European and OECD countries.

Open Access: Yes

DOI: 10.1556/650.2019.31395