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Found 6374 publications

Improving performance prediction of parallel and distributed discrete event simulation: A rough sets-based approach

No authors available

Publication Name: 11th International Industrial Simulation Conference 2013, ISC 2013

Publication Date: 2013-01-01

Volume:

Issue:

Page Range: 95-100

Description:

The rapid growth of complexity of communication networks - including grids, cloud systems and services - increases the need for the use and performance prediction of parallel and distributed discrete event simulation. The paper aims at the decreasing the overall cost of simulation by improving the performance prediction of simulation particularly for the phases with uncertain and vague information. Involving rough sets-based methods, the paper introduces how the efficiency of the well known coupling factor method of the performance prediction of parallel and distributed simulation can be improved. According to the presented results, the prediction can merely be based on the maintainable lookahead feature of the designed simulation model. Using the rough set analysis, the paper also describes how the number of simulation experiments necessary for prediction can be limited without the decrease of accuracy of prediction.

Open Access: No

DOI: DOI not available

Holistic evaluation of energy transition technology investments using an integrated recommender system and artificial intelligence-based fuzzy decision-making approach

Dragan Pamucar Hasan Dincer Muhammet Deveci Ümit Hacioglu Serhat Yuksel Serkan Eti

Publication Name: Results in Engineering

Publication Date: 2024-09-01

Volume: 23

Issue: Unknown

Page Range: Unknown

Description:

The most essential criteria should be determined in the selection of the suitable energy transition technologies due to budget deficit problem. Therefore, it is necessary to identify the most important criteria in energy transition technology selection. Therefore, a new study is needed to determine the most prominent issues in the correct selection of energy transition technologies. The purpose of this study is to identify the most appropriate energy transition technology alternative. Within this framework, a novel artificial intelligence (AI)-based fuzzy decision-making model has been presented. In the first part, the experts are prioritized by the help of AI methodology. In the next section, missing evaluations of energy transition technology investments are estimated via expert recommender system. Thirdly, the weights of the criteria for energy transition technology selection are computed by quantum picture fuzzy rough sets (QPFR) M-Stepwise Weight Assessment Ratio Analysis (SWARA). At the final stage, selected energy transition technology alternatives are ranked via QPFR-Vlse Kriterijumska Optimizacija Kompromisno Resenje (VIKOR). The main contribution of this study is the integration of AI technique to the proposed model. Similar to this issue, using M-SWARA methodology in the process of criteria weighting increases the quality of the findings. This methodology helps to consider the impact relation map of the criteria. The findings demonstrate that the most important factor is cost-effectiveness of energy transition. Similarly, it is also found that the local ecosystem is the second most significant issue. On the other side, the ranking results denote that compact renewable systems for small scale production is the most optimal solution of energy transition technology alternatives.

Open Access: Yes

DOI: 10.1016/j.rineng.2024.102806

Structural Optimization of a Steel Truss for Sustainability in Parametric Environment – a Case Study

János Szép Kitti Karolyfi G. Hajdú Kira Rodaeva

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 13-18

Description:

Although designing a structure is an iterative process by nature, a very limited number of iterations can be done with the traditional methods to reach the near-optimal solution. However, with the development of information technologies, the usage of parametric design in the construction industry has expanded. This paper aims to show the potential benefits of implementing parametric design and optimization techniques in the early structural design process. For this purpose, a simple parametric model of a steel frame with a truss roof system was created and then optimized for minimum mass and a given floor area. The case study demonstrated that the application of parametric design can reduce the Global Warming Potential of the structure by 7.6 % by optimizing the geometry and the cross-sections, leading to a more sustainable solution.

Open Access: Yes

DOI: 10.3303/CET23107003

Performance evaluation of wire pairs in telecommunications networks by fuzzy and evolutionary models

Ferenc Lilik Laszlo T. Koczy

Publication Name: IEEE AFRICON Conference

Publication Date: 2013-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

This paper is dealing with a new approach for the performance evaluation of symmetrical wire pairs of telecommunications access networks. In this method the determination of the available data transmission rates is performed by fuzzy inference systems. The telecommunications environment and the physical parameters that influence the transmission are briefly reviewed. Two methods used for the creation of the rule bases and an easy way for the evaluation for the observations of the physical system are presented. © 2013 IEEE.

Open Access: Yes

DOI: 10.1109/AFRCON.2013.6757602

Developing fuzzy cognitive maps for modeling regional waste management systems

No authors available

Publication Name: Civil-Comp Proceedings

Publication Date: 2013-01-01

Volume: 103

Issue:

Page Range: Unknown

Description:

Sustainable waste management systems necessarily include environmental, economic, social, institutional, legal and technical aspects. As a result of the incompleteness and multiple uncertainties occurring in sustainable waste management systems, we propose the use of fuzzy cognitive maps (FCM) to support the planning and decision making process. It is obvious that uncertainties involved with waste management represent vagueness rather than probability. Fuzzy sets and fuzzy logic are suitable to construct a formal description and a mathematically manageable model of systems and processes with such uncertainties. In the research described in this paper the FCM model of the Gyor RWMS is established and implemented in such a structure that its parameters and weights were flexibly variable. By observation of the model and its time dependent behaviour we determined under what conditions the long-term sustainability of a regional waste management system could be ensured. In this paper, the interpretation of the results obtained by the FCM model for the actual waste management system are presented. ©Civil-Comp Press, 2013.

Open Access: No

DOI: DOI not available

Thermal examination of a simplified exhaust tube-heatshield model

Balázs Vehovszky Tamás Jakubík Marcell Treszkai

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2019-01-01

Volume: 47

Issue: 3

Page Range: 190-195

Description:

Exhaust system and its surrounding is a thermally highly critical part of a vehicle: during forced operation, hottest elements can reach 600 °C. The thermal conditions turn to even more critical if the forced flow leaves off – e.g. when the car stops at a highway parking place. In such a case not only the cooling effect of cross-flow disappears, but the natural convection starts to bring heat toward nearby elements – resulting potential overheating of concerned parts. A measurement setup for modelling such case was built, and different parameters were examined, which have influence on the heating of aluminium heatshield above the exhaust tube. Measurements were complemented by CFD simulations and flow visualization technique aiming the better understanding of evolving thermal and flow conditions.

Open Access: Yes

DOI: 10.3311/PPtr.12109

Comparison of plant biostimulating properties of Chlorella sorokiniana biomass produced in batch and semi-continuous systems supplemented with pig manure or acetate

Miroslav Strnad Péter Bálint Zoltán Varga Gergely Maróti Jácint Notterpek Jitka Široká Vince Ördög Tamás Rétfalvi Zoltán Berzsenyi Wendy A. Stirk Ondřej Novák Johannes van Staden

Publication Name: Journal of Biotechnology

Publication Date: 2024-02-10

Volume: 381

Issue: Unknown

Page Range: 27-35

Description:

Microalgae-derived biostimulants provide an eco-friendly biotechnology for improving crop productivity. The strategy of circular economy includes reducing biomass production costs of new and robust microalgae strains grown in nutrient-rich wastewater and mixotrophic culture where media is enriched with organic carbon. In this study, Chlorella sorokiniana was grown in 100 l bioreactors under sub-optimal conditions in a greenhouse. A combination of batch and semi-continuous cultivation was used to investigate the growth, plant hormone and biostimulating effect of biomass grown in diluted pig manure and in nutrient medium supplemented with Na-acetate. C. sorokiniana tolerated the low light (sum of PAR 0.99 ± 0.18 mol/photons/(m2/day)) and temperature (3.7–23.7° C) conditions to maintain a positive growth rate and daily biomass productivity (up to 149 mg/l/day and 69 mg/l/day dry matter production in pig manure and Na-acetate supplemented cultures respectively). The protein and lipid content was significantly higher in the biomass generated in batch culture and dilute pig manure (1.4x higher protein and 2x higher lipid) compared to the Na-acetate enriched culture. Auxins indole-3-acetic acid (IAA) and 2-oxindole-3-acetic acid (oxIAA) and salicylic acid (SA) were present in the biomass with significantly higher auxin content in the biomass generated using pig manure (> 350 pmol/g DW IAA and > 84 pmol/g DW oxIAA) compared to cultures enriched with Na-acetate and batch cultures (< 200 pmol/g DW IAA and < 27 pmol/g DW oxIAA). No abscisic acid and jasmonates were detected. All samples had plant biostimulating activity measured in the mungbean rooting bioassay with the Na-acetate supplemented biomass eliciting higher rooting activity (equivalent to 1–2 mg/l IBA) compared to the pig manure (equivalent to 0.5–1 mg/l IBA) and batch culture (equivalent to water control) generated biomass. Thus C. sorokiniana MACC-728 is a robust new strain for biotechnology, tolerating low light and temperature conditions. The strain can adapt to alternative nutrient (pig manure) and carbon (acetate) sources with the generated biomass having a high auxin concentration and plant biostimulating activity detected with the mungbean rooting bioassay.

Open Access: Yes

DOI: 10.1016/j.jbiotec.2024.01.002

Reconstruction of 3D Porous Geometry for Coupled FEM-CFD Simulation

H. Szűcs

Publication Name: Periodica Polytechnica Mechanical Engineering

Publication Date: 2022-01-01

Volume: 66

Issue: 2

Page Range: 129-136

Description:

Porous materials can be found in numerous areas of life (e. g., applied science, material science), however, the simulation of the fluid flow and transport phenomena through porous media is a significant challenge nowadays. Numerical simulations can help to analyze and understand physical processes and different phenomena in the porous structure, as well as to determine certain parameters that are difficult or impossible to measure directly or can only be determined by expensive and time-consuming experiments. The basic condition for the numerical simulations is the 3D geometric model of the porous material sample, which is the input parameter of the simulation. For this reason, geometry reconstruction is highly critical for pore-scale analysis. This paper introduces a complex process for the preparation of the microstructure's geometry in connection with a coupled FEM-CFD two-way fluid-structure interaction simulation. Micro-CT has been successfully applied to reconstruct both the fluid and solid phases of the used porous material.

Open Access: Yes

DOI: 10.3311/PPme.19438

Diagnostic measurement for the effective performance of motor vehicles

No authors available

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2013-01-01

Volume: 10

Issue: 3

Page Range: 239-249

Description:

Diagnostics means instrumental measurement without dismantling. So measuring the engines on rolling roads is not incorporated in this concept, as this measurement is accomplished on engines taken out from vehicles. During service, it is often necessary to measure the performance of the engines, or to judge the performance projection of some corrections. The new method discussed in this article provides a solution to this problem.

Open Access: No

DOI: DOI not available