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Found 6515 publications

Advanced learning of fuzzy cognitive maps of waste management by bacterial algorithm

Miklós F. Hatwagner Claudiu Pozna Adrienn Buruzs Laszlo T. Koczy

Publication Name: Proceedings of the 2013 Joint Ifsa World Congress and NAFIPS Annual Meeting Ifsa NAFIPS 2013

Publication Date: 2013-10-31

Volume: Unknown

Issue: Unknown

Page Range: 890-895

Description:

Fuzzy cognitive maps (FCMs) are a very convenient and simple tool for modeling complex systems. They are popular due to their simplicity and user friendliness. However, according to [1], human experts are subjective and can handle only relatively simple networks therefore there is an urgent need to develop methods for automated generation of FCM models. The present research deals with the methodology of FCMs in combination with the Bacterial Evolutionary Algorithm (BEA). The method of FCMs using BEA seems to be suitable to model such complex mechanisms as integrated municipal waste management (IMWM) systems. This paper is an attempt to assess the sustainability of the IMWM system by investigating the FCM methodology based on the BEA with a holistic approach. As a result, the best scenario to an IMWM system can be assigned. © 2013 IEEE.

Open Access: Yes

DOI: 10.1109/IFSA-NAFIPS.2013.6608518

Feeding models of wire antennas

Miklós Kuczmann

Publication Name: Przeglad Elektrotechniczny

Publication Date: 2011-04-26

Volume: 87

Issue: 3

Page Range: 107-110

Description:

Antenna parameters (e.g. input impedance, radiation pattern) can be measured in Full Anechoic Chambers (FAC). The simulated input impedance is depending on the applied feed model. The most frequently used models are the current probe model, the voltage gap generator, the magnetic frill generator and the waveguide port which are presented in this paper focusing on a simple example, a monopole antenna situated above a ground plane. The Finite Element Method (FEM) has been used in the numerical field analysis.

Open Access: Yes

DOI: DOI not available

Identification and reconstruction of car body deformation applying tensor product models

István Harmati András Rövid Péter Várlaki Lászlõ Szeidl

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

Publication Date: 2006-12-01

Volume: Unknown

Issue: Unknown

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: Yes

DOI: DOI not available

Integrated experimental design and nonlinear optimization to handle computationally expensive models under resource constraints

János D. Pintér Zoltán Horváth

Publication Name: Journal of Global Optimization

Publication Date: 2013-09-01

Volume: 57

Issue: 1

Page Range: 191-215

Description:

In many real-world applications of optimization, the underlying descriptive system model is defined by computationally expensive functions: simulation modules, numerical models and other "black box" model components are typical examples. In such cases, the model development and optimization team often has to rely on optimization carried out under severe resource constraints. To address this important issue, recently a Regularly Spaced Sampling (RSS) module has been added to the Lipschitz Global Optimizer (LGO) solver suite. RSS generates non-collapsing space filling designs, and produces corresponding solution estimates: this information is passed along to LGO for refinement within the given resource (function evaluation and/or runtime) limitations. Obviously, the quality of the solution obtained will essentially depend both on model instance difficulty and on the admissible computational effort. In spite of this general caveat, our results based on solving a selection of non-trivial global optimization test problems suggest that even a moderate amount of well-placed sampling effort enhanced by limited optimization can lead at least to reasonable or even to high quality results. Our numerical tests also indicate that LGO's overall efficiency is often increased by using RSS as a presolver, both in resource-constrained and in completed LGO runs. © 2012 Springer Science+Business Media, LLC.

Open Access: Yes

DOI: 10.1007/s10898-012-9882-7

Psychometric Validation of the Modified, Short Version of the Problematic Pornography Consumption Scale in Serbian

Beáta Bőthe Aleksandar Vujić Marija Volarov Nikolina Kuruzović Slavica Adamović Zdravković Attila Szabo

Publication Name: Sexual Health and Compulsivity

Publication Date: 2025-01-01

Volume: 32

Issue: 2

Page Range: 105-128

Description:

Pornography is used worldwide, and 3% of individuals may experience problematic pornography use (PPU, i.e. poorly controlled use resulting in significant distress and negative consequences). Therefore, instruments gauging PPU are needed in nation-specific languages. This study aimed to validate a modified version of the Problematic Pornography Consumption Scale-6 (PPCS-6) in the Serbian language among 1413 adults (52.9% males) aged from 18 to 54 (Mage = 24.96, SD = 4.46). Exploratory factor analysis on the sample’s random half yielded a single factor explaining 43% of the total variance. Confirmatory factor analysis on the sample’s other half revealed an acceptable model fit. Internal consistency (Cronbach’s alpha) was acceptable. The scale exhibited configural and partial metric invariance across genders and convergent validity. Latent profile analysis identified that 8.1% of the participants were at risk of experiencing PPU. In comparison, this value was 9.6% based on a calculated cutoff score (≥ 19) with acceptable values (.69 and.96) of sensitivity and specificity. To conclude, the Serbian modified version of the PPCS-6 appears to be a valid and reliable scale for screening PPU.

Open Access: Yes

DOI: 10.1080/26929953.2024.2448110

Surface modification and wear properties of direct metal laser sintered hybrid tools used in moulds

Imre Fekete József G. Kovács Tamás Ibriksz Mária B. Maros István Hatos Hajnalka Hargitai

Publication Name: Journal of Mechanical Engineering

Publication Date: 2018-01-01

Volume: 64

Issue: 2

Page Range: 121-129

Description:

Injection moulding is one of the most productive plastic forming processes. Product development and the reduction of production time require new solutions in tooling design and manufacturing. Direct metal laser sintering (DMLS) allows moulds to be built with special cooling systems, which offer curved cooling lines that can follow the geometry of the part (conformal cooling). One disadvantage of DMLS, its high cost, can be dramatically reduced with the building of hybrid structures. With conventional tool steels as the base plate and only the special geometry of the part sintered on the top, the final geometry can be manufactured after sintering by conventional process technologies. We produced hybrid structures by direct metal laser sintering maraging steel (MS1) powder onto the surface of commercial mould steels and studied the effect of different heat treatments on porosity, tribological behaviour and the microstructure. The transition zone was also characterized.

Open Access: Yes

DOI: 10.5545/sv-jme.2017.4942

Analysis of the Effect of Mixed Eccentricity Fault on Controlled Induction Machines via Finite Element Method

György Istenes Krisztian Horvath

Publication Name: 2025 19th International Conference on Electrical Machines Drives and Power Systems Elma 2025 Proceedings

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The eccentricity in induction machines is a geometrical fault when the axis of rotation deviates from the ideal. As a result, the air gap between the stator and the rotor varies. Since the eccentricity is caused by a geometric misalignment, finite element method is used to model the fault in this paper and the phenomenon is detected by spectral analysis of the stator currents. In addition, the effect of eccentricity on the controlled drive is also investigated by numerical simulations.

Open Access: Yes

DOI: 10.1109/ELMA65795.2025.11083515

Differences, constraints and key elements of providing local sharing economy services in different-sized cities: A Hungarian case

Katalin Czakó Dávid Fekete Kinga Szabó Marcell Tóth

Publication Name: Resources

Publication Date: 2019-09-01

Volume: 8

Issue: 3

Page Range: Unknown

Description:

The business models of sharing economy services can differ fromeach other in different-sized cities. This paper provides a deeper understanding of the implementation of locally operating services for car, bicycle and office sharing in the urban environment. Our goal is to reveal the differences between the capital city and an economically well-developed city in order to provide beneficial findings to the development of the presently operating services, or to the possible implementation of future services. Methodology of the paper applies the Business Model Canvas approach (BMC). We introduce a comparative analysis using data from the Hungarian database, which records details of all the publicly visible sharing economy services countrywide. The results show that BMC can reflect the main differences, constraints and key elements in the business models of sharing economy services. We can say that, in the case of a bike sharing service operated in the non-capital city, there is more segmentation than seen in the same service in the capital. There are significant price differences, especially in the case of long-term tickets. The number of inhabitants and private capital remain the biggest constraints in the case of car-sharing services, but there is also a possibility of implementation in the non-capital cities by applying small-scale services with a good value proposition and segmentation.

Open Access: Yes

DOI: 10.3390/resources8030147

Revolutionizing sugar beet yield and quality in saline sandy soil through synergistic humic acid, glauconite, and boron foliar application

Tarek Alshaal Nevien Elhawat Mohamed A.Abd El-Aziz R. M. Khalifa Amira E. El-Sherief Mahmoud M.A. Shabana Asmaa F.M. Badawy Ahmed K.H. Amer Amira E. El-Sherief

Publication Name: Plant and Soil

Publication Date: 2026-05-01

Volume: 522

Issue: 2

Page Range: 1199-1230

Description:

Aims: Saline sandy soils severely constrain sugar beet (Beta vulgaris L.) productivity due to low nutrient retention, high salinity, and micronutrient imbalances, particularly boron deficiency. Although humic substances, glauconite, and boron fertilization have individually or pairwise improved crop performance, no previous field study has evaluated their ternary, dose-optimized integration as a multifunctional soil–plant management strategy under saline sandy conditions. Methods: This study investigated, for the first time, the combined application of soil-applied humic acid (600 kg/ha), glauconite (1100 kg/ha), and graded foliar boric acid (0, 1900, and 3800 g/ha) to test the hypothesis that their complementary physicochemical and physiological mechanisms would generate synergistic improvements in soil quality, crop performance, and sugar productivity beyond additive effects. Field experiments were conducted over two consecutive growing seasons (2021–2022) in West Minya, Egypt, using a split-plot design. Results: The integrated high-dose treatment (HG3800) significantly enhanced leaf area index (by 75%), chlorophyll content (46–71%), and net photosynthetic rate (40–128%) relative to the control. Root yield increased by 27% (reaching 56.7 ton/ha), while sugar yield rose by up to 79% (11.5 ton/ha). Sucrose concentration reached 20.4%, with reduced impurity indices and improved extractable sugar percentage (up to 90%). Based on fermentable sugar yield, the HG3800 treatment corresponded to a substantial increase in theoretical bioethanol output potential per hectare. Concurrently, soil electrical conductivity declined by 24%, soil organic matter increased, and bulk density decreased, reflecting improved soil structure and salinity mitigation. Conclusions: The ternary, dose-optimized integration of humic acid, glauconite, and foliar boron represents a novel agronomic strategy that simultaneously enhances soil physicochemical properties, physiological efficiency, and fermentable sugar production. By directly linking yield gains to increased bioethanol feedstock potential, this approach offers a scalable and multifunctional pathway for sustainable bioenergy-oriented sugar beet production in salt-affected sandy soils.

Open Access: Yes

DOI: 10.1007/s11104-026-08574-9