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Found 6515 publications

Change in Stiffness of Reinforced Concrete Tunnel Walls and Its Effect Under Fire Load

E. Koch Éva Lublóy Zoltán Major

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 342-350

Description:

This article uses the knowledge gained from tunnel fires to address the structural analysis of tunnel walls during fire exposure. The designing at normal temperature and its theoretical background are discussed in the literature. As these books did not yet deal with the issue of fire protection designing, we tried to supplement the existing theoretical knowledge with the knowledge provided by the relevant standards for reinforced concrete tunnel walls. In addition, we have tried to add our own individual ideas to the theory where we felt that there were gaps. The theoretical summary has been compiled in such a way that it can be easily transferred and applied to everyday practice. In this article, we discuss in detail the calculation of the internal forces in tunnel walls during fire exposure. Due to space constraints, the issue of designing at normal temperatures is only touched upon in this article, limiting it to the knowledge available in the literature. Since finite element modelling has become a commonly used technique in tunnel design since the 1970s, we use its potential to investigate the effects of earth pressure and surface loads on the tunnel walls during fire and their changes, using specific software for geotechnical design. In accordance with the limitations of the scope, the determination of the equivalent thickness and the modulus of elasticity of the tunnel wall is also presented in order to determine the internal forces during the fire action.

Open Access: Yes

DOI: 10.3233/ATDE240565

Mathematical Description of the Universal IDM - some Comments and Application

Tibor Vadvári Istvan Lakatos Krisztián Szabó András Háry Tamás Péter Ferenc Szauter

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2023-01-01

Volume: 20

Issue: 7

Page Range: 99-115

Description:

The aim of the study is to define and mathematically describe the universal IDM. An important result of this research is that the model uses a single system of differential equations. It is able to simultaneously describe the dynamic operations of the IDM systems for all different vehicle sequences. The aim of the study is to support the driving of autonomous vehicles by taking into account the dynamic variations in the state characteristics of traffic processes. The approach used is motivated by important issues in current modelling techniques that address significant economic problems in the application of large-scale ITS network models. This also points to a new opportunity in the key area of vehicle traffic management, in the related targeted fundamental research, particularly in the analysis of traffic processes in large-scale dynamic networks.

Open Access: Yes

DOI: 10.12700/APH.20.7.2023.7.6

Companies Local Embeddedness and Culture: A Review

Zsuzsanna Pálffy

Publication Name: Economic Research Guardian

Publication Date: 2024-01-01

Volume: 14

Issue: 2

Page Range: 73-87

Description:

The criticism of neoclassical economic behaviour, the changing company-space dynamics, the effects of globalization, and the cultural turn have stimulated new trends in social sciences. In recent decades, the concept of embeddedness has evolved significantly and now holds a solid place in regional economics and economic geography; however, interdisciplinary studies remain common. This review article examines the interaction between corporate embeddedness and culture, aiming to demonstrate how previous research has interpreted culture's role in embeddedness. A comprehensive literature analysis, the primary question addressed is how corporate practices and cultural norms develop in a specific socio-cultural context. The review's novelty lies in its dual approach to culture's role in embeddedness. On one hand, it explores the value and norm system of embeddedness, focusing on culture's role in limiting social practices. On the other hand, it discusses culture's role in the interactions of the embedding process at all levels of embeddedness and culture. The literature indicates that the culture of both the company and the receiving space – including trust levels, openness, willingness to settle, and receptiveness – determines the success of embeddedness.

Open Access: Yes

DOI: DOI not available

The effect of image feature qualifiers on fuzzy colorectal polyp detection schemes using KH interpolation - Towards hierarchical fuzzy classification of coloscopic still images

Brigita Sziová Laszlo T. Koczy Szilvia Nagy

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2018-10-12

Volume: 2018-July

Issue: Unknown

Page Range: Unknown

Description:

Previous studies showed that intensities, intensity variation, edge densities, structural entropies of colonoscopy images and their wavelet transforms are good candidates for being selected as antecedents in fuzzy decision methods using KH interpolation for determining whether an image segment contains colorectal polyp segment. In the present consideration, we check which possible antecedent dimensions need interpolation, whether the average and variation of the gradients makes the classification more effective and whether some of the features can be omitted for some classes of images. The method is tested on three available databases consisting of images of three different resolutions, and according to the results, different resolutions, different types of polyps require different classification schemes, thus a hierarchical decision system needs to be built.

Open Access: Yes

DOI: 10.1109/FUZZ-IEEE.2018.8491479

Analysis and design of electrical circuits by ANA method

Miklós Kuczmann Éva Katona

Publication Name: Przeglad Elektrotechniczny

Publication Date: 2009-12-01

Volume: 85

Issue: 12

Page Range: 69-72

Description:

The paper presents a software, which includes the functions available in the other networks and systems, but it gives a user friendly interface. The program, called ANA (Advanced Network Analysis) is to give an easy use for students, engineers and researchers as well.

Open Access: Yes

DOI: DOI not available

A simultaneous solution for general linear equations with subspace decomposition

N. Varjasi Gyozo Molnárka

Publication Name: Civil Comp Proceedings

Publication Date: 2011-01-01

Volume: 95

Issue: Unknown

Page Range: Unknown

Description:

For solving linear systems of equations there are several known algorithms. For large linear systems with a sparse matrix iteration algorithms are recommended. But in the case of general n x m matrices the classic iterative algorithms are not applicable with a few exceptions. For example in some cases the Lanczos type algorithms are adequate. The algorithm presented here based is on the minimization of residual solution with subspace decomposition. Therefore this algorithm seems to be applicable for the construction of parallel algorithms. In this paper we describe a sequential version of proposed algorithm first and give its theoretical analysis. The algorithm has some genetic characteristics. After this we will formulate a parallel version of algorithm with subspace decomposition in order to study the details of convergence and the speed up effect of the parallel algorithms. The numerical test results of these algorithms including the speed-up effects of the parallel execution will be shown. The comparison of the classical method and the new approach will also be presented considering the running speed and efficiency too. The computer tests have been carried out with parallel and cluster computing methods as well. © Civil-Comp Press, 2011.

Open Access: Yes

DOI: DOI not available

Synergistic effects of nitrogen, sewage sludge, and poultry manure on integrative fertilization for wheat and sugar beet in marginally saline soil

Szilvia Veres Tarek Alshaal Nevien Elhawat

Publication Name: Frontiers in Plant Science

Publication Date: 2026-01-01

Volume: 17

Issue: Unknown

Page Range: Unknown

Description:

Introduction – Soil salinity is a major constraint to agricultural productivity in arid and semi-arid regions, affecting approximately 1.4 billion hectares globally (over 10% of the world’s land area) and causing substantial yield losses in staple crops, with reductions reaching up to 50% or more in sensitive species under moderate salinity levels. Methods – While the individual effects of biofertilizers or organic amendments have been widely studied, there remains a critical gap in field-based evidence regarding their synergistic integration—particularly the combined use of dual nitrogen (N2)-fixing plant growth-promoting rhizobacteria (Azotobacter chroococcum and Azospirillum lipoferum) with a balanced blend of sewage sludge and poultry manure (1:1 on N basis) as a 50% substitution for inorganic N in marginally saline soils. This study aimed to evaluate the effects of such integrated fertilization on soil health, nutrient availability, physiological performance, and productivity of wheat (Triticum aestivum L. cv. Sakha 93) and sugar beet (Beta vulgaris L. cv. Kawemira) in marginally saline soil (initial ECe 3.47 dS/m). A strip-plot field experiment with five treatments was conducted: control (T1), biofertilizer alone (T2), 50% inorganic N + 50% organic manure (T3), biofertilizer + T3 (T4), and conventional NPK (T5). Soil and plant parameters were assessed at 70 days after sowing (DAS), with final yield and quality parameters determined at harvest. Results and discussion – Treatment T4 significantly improved soil organic matter (23.3 g/kg in wheat and 22.9 g/kg in sugar beet), reduced ECe (to 3.90 dS/m in wheat and 3.13 dS/m in sugar beet), and enhanced available N (up to 63.0 mg/kg) and potassium. It also increased microbial biomass carbon, soil enzyme activities, photosynthetic rate (14.0 µmol CO2/m2/s in wheat and 26.5 µmol CO2/m2/s in sugar beet), and alleviated salinity-induced stress indicators. The highest yields were recorded under T4, with wheat grain yield reaching 6719 kg/ha and sugar beet root yield 78.8 tons/ha, accompanied by superior sugar quality. These results demonstrate that the integration of dual PGPR with blended organic amendments (T4) offers a synergistic, low-input strategy that enhances soil fertility, mitigates salinity stress, and boosts crop productivity while reducing inorganic fertilizer use by 50%. This approach provides a scalable and sustainable solution for marginally saline soils in arid regions, supporting food security with a reduced environmental footprint. Further multi-site and multi-year validation across a wider range of salinity levels and soil types is recommended.

Open Access: Yes

DOI: 10.3389/fpls.2026.1827328

Rattling detection of electric components

Zoltán Gazdagh J. A. Erdelyi A. Bartus B. Fukker

Publication Name: Proceedings of ISMA 2024 International Conference on Noise and Vibration Engineering and Usd 2024 International Conference on Uncertainty in Structural Dynamics

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 2799-2813

Description:

The study emphasizes the importance of detecting and addressing the issue of nonlinear phenomena in electronic components, due to their potential implications for structural integrity, damage or malfunction to sensitive electronic elements, and a reduction in overall vehicle reliability. This investigation based on time-domain experimental data facilitates rattling detection that aims to distinguish rattling from other type of nonlinearities. The sample is screwed on a fixture, which is mounted on an electrodynamic shaker that serves as the excitation source. The excitation signal is a closed loop sinusoidal sweep, measured in both directions and at different amplitudes. The paper will focus on several methods for identifying nonlinear phenomena, such as the Poincare map or Hilbert transformation. Phase plots are produced, that serve as a valuable tool for studying anomalies, which can be correlated to the extremes of Lyapunov exponents. The above methods are evaluated on their ability to separate rattling form other phenomena to identify genuine instances of rattling.

Open Access: Yes

DOI: DOI not available

Evaluation of dummy-head HRTFs in the horizontal plane based on the peak-valley structure in one-degree spatial resolution

György Wersényi

Publication Name: Institute of Noise Control Engineering of the Usa 35th International Congress and Exposition on Noise Control Engineering Inter Noise 2006

Publication Date: 2006-12-01

Volume: 7

Issue: Unknown

Page Range: 4487-4495

Description:

Dummy-heads are often used for standardized measurements where modeling of the human head and torso is relevant. Monaural Head-Related Transfer Functions of a Brüel & Kjaer dummy were measured in the horizontal plane in one-degree spatial resolution. Evaluation is made by plotting the peak-valley structure in frequency. Special frequency and spatial domains can be determined based on the variations of the HRTFs that are relevant to understand physical properties of the dummy -head in measurements and processes of human directional hearing. Symmetries and similarities of measured HRTFs help to scrutinize the perception of directional information in the monaural and binaural evaluation, the "noisy domain" in frequency and space where shadowing of the head occur as well as the filtering effect of the pinna.

Open Access: Yes

DOI: DOI not available