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Found 6674 publications

Simulation of 3-dimensional cell population growth processes in polyhedral cellular systems

I. Zsoldos Tamás Réti

Publication Name: Materials Science Forum

Publication Date: 2007-01-01

Volume: 537-538

Issue: Unknown

Page Range: 579-590

Description:

In order to simulate the polyhedral grain nucleation in alloys, 3-D cell population growth processes are studied in space-filling periodic cellular systems. We discussed two different methods by which space-filling polyhedral cellular systems can be constructed by topological transformations performed on "stable" 3-D cellular systems. It has been demonstrated that an infinite sequence of stable periodic space-filling polyhedral systems can be generated by means of a simple recursion procedure based on a vertex based tetrahedron insertion. On the basis of computed results it is conjectured that in a 3-D periodic, topologically stable cellular system the minimum value of the average face number 〈f〉 of polyhedral cells is larger than eight (i.e. 〈f〉 > 8). The outlined algorithms (which are based on cell decomposition and/or cell nucleation) provide a new perspective to simulate grain population growth processes in materials with polyhedral microstructure.

Open Access: Yes

DOI: 10.4028/0-87849-426-x.579

Effect of junction type on the vibroacoustic response of a system of plates

Daniel Feszty Marcell Treszkai

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:

Modelling of junctions is one of the most challenging tasks in vibroacoustics, especially for Statistical Energy Analysis (SEA), where the results heavily depend on the damping (DLF) and coupling loss factors (CLF). Also, it is an interesting question to determine that to what extent does the DLF or CLF contribute to the overall vibroacoustic characteristics of a structure? The aim of this paper is to investigate via measurements and SEA simulations the effect of the ratio of DLF and CLF on the response of a system for various junctions, such as riveting, bolting, line and point welding, between two steel plates. Loss matrices are determined experimentally by the Power Injection Method in the 200-1600 Hz frequency range. The simulation was performed in the ESI VA One software by using its analytical CLF formulations and compared to experimental data. For the reference case, a bended plate structure was considered, representing an ideal junction between two subsystems. This was equipped with damping foils to ensure the same weight and then compared to the results from other joints. Results showed that increasing the CLF could be more effective than focusing on increasing the DLF.

Open Access: Yes

DOI: 10.3397/IN-2021-2565

Performance Comparison of the General the Dual and the Joint Extended Kalman Filter on State Estimation of Li-ion Battery Cells for BMS

Tamás Horváth Denes Fodor

Publication Name: 2024 IEEE 21st International Power Electronics and Motion Control Conference Pemc 2024

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The aim of the work is to compare the performance of the general Extended Kalman Filter (EKF), the joint EKF and the dual EKF for state and parameter estimation of a Samsung 18650INR13L Li-ion battery cell. The used battery model is based on a simplified Randles equivalent circuit equipped with Rs, Rct and Cdl parameters. The initial values of Randles parameters were identified from constant charge, discharge and transient discharge measurements. The performance of the implemented Kalman Filters were compared for the state and parameter estimation of the cell during WLTP test condition. While the general EKF uses only the identified initial values of the parameters, the joint and dual EKF are able to estimate them to compensate for the drift during the operation which leads to more accurate state estimation and compensates the parameters change due to heat and the aging of the cell. From the SOC estimation performance comparison we found out that both the dual and joint EKF perform similarly well, but the dual EKF has about 22% less computational cost which is very significant in the case of the future implementation on a real Battery Management System (BMS) which was the target of this investigation.

Open Access: Yes

DOI: 10.1109/PEMC61721.2024.10726344

Socio-ecological network structures from process graphs

Angelyn Lao Ákos Orosz Raymond R. Tan Heriberto Cabezas Ferenc Friedler

Publication Name: Plos One

Publication Date: 2020-08-01

Volume: 15

Issue: 8 August

Page Range: Unknown

Description:

We propose a process graph (P-graph) approach to develop ecosystem networks from knowledge of the properties of the component species. Originally developed as a process engineering tool for designing industrial plants, the P-graph framework has key advantages over conventional ecological network analysis techniques based on input-output models. A P-graph is a bipartite graph consisting of two types of nodes, which we propose to represent components of an ecosystem. Compartments within ecosystems (e.g., organism species) are represented by one class of nodes, while the roles or functions that they play relative to other compartments are represented by a second class of nodes. This bipartite graph representation enables a powerful, unambiguous representation of relationships among ecosystem compartments, which can come in tangible (e.g., mass flow in predation) or intangible form (e.g., symbiosis). For example, within a P-graph, the distinct roles of bees as pollinators for some plants and as prey for some animals can be explicitly represented, which would not otherwise be possible using conventional ecological network analysis. After a discussion of the mapping of ecosystems into P-graph, we also discuss how this framework can be used to guide understanding of complex networks that exist in nature. Two component algorithms of P-graph, namely maximal structure generation (MSG) and solution structure generation (SSG), are shown to be particularly useful for ecological network analysis. These algorithms enable candidate ecosystem networks to be deduced based on current scientific knowledge on the individual ecosystem components. This method can be used to determine the (a) effects of loss of specific ecosystem compartments due to extinction, (b) potential efficacy of ecosystem reconstruction efforts, and (c) maximum sustainable exploitation of human ecosystem services by humans. We illustrate the use of P-graph for the analysis of ecosystem compartment loss using a small-scale stylized case study, and further propose a new criticality index that can be easily derived from SSG results.

Open Access: Yes

DOI: 10.1371/journal.pone.0232384

Choices Based on the Self-Perception of University Applicants in their Decisions on Applying to Higher Education

Eszter Lukács Attila Miklós

Publication Name: Decision Making Applications in Management and Engineering

Publication Date: 2024-01-01

Volume: 7

Issue: 1

Page Range: 603-623

Description:

This paper investigates the role of self-concept and perceptions of academic performance in shaping university students’ choice of educational institutions, as well as the factors that influence these decisions. Various empirical studies have examined this topic, identified key determinants and reflected the aspects and expectations that students prioritize when making decisions about their academic future. In this study, we utilized scientific databases to filter through thousands of papers, ultimately selecting 225 articles that were directly related to decision-making processes in education. Out of these, we have cited 60 publications that offer significant insights relevant to our research. Moreover, we identified 20 empirical studies that specifically analyse the factors that influence students’ decision-making processes, based on data gathered through questionnaires and interviews. To further explore students' career aspirations and understand the factors influencing their choices, we focus on several key variables. These include students' self-perception, self-confidence, and personal development. We also assess how external factors, such as socioeconomic conditions, family expectations, and educational environment, may impact these decisions. By examining these elements, we aim to uncover how such influences contribute to students' educational and professional trajectories. This study seeks to clarify how diverse influences, particularly those experienced during adolescence, shape individuals’ personal growth and career pathways. In addition, it aims to identify any gaps in existing research, especially with regard to international practices and trends, thereby contributing to the broader understanding of student decision-making in higher education.

Open Access: Yes

DOI: 10.31181/dmame7120241274

The Connections Between Science and State Decision-Making

Áron Ősze

Publication Name: Rechtskultur

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 451-465

Description:

Science has been and is a fundamentally defining factor in human history. Current achievements in technology, scientific development and the scientific method make it possible to explain, verify on a scientific basis any and all phenomena occurring today. Accordingly, science has a fundamental impact on how society operates. However, the proper functioning of society needs more: normative standards that the government, as public authority, can create (legislation) and implement (law enforcement) through its various governmental bodies. But how does this connect to science and scientific achievements? How do scientific achievements determine or may determine governmental function? In order to even attempt answering these questions, we have to take a detailed look at scientific thinking. In my study, I have prepared a thorough overview of the characteristics of science and scientific thinking, and their interconnections with governmental decision-making.

Open Access: Yes

DOI: DOI not available

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 hybrid decision making focused on legal processes

Krisztina Varlaki Peter Baranyi

Publication Name: 9th IEEE International Conference on Cognitive Infocommunications Coginfocom 2018 Proceedings

Publication Date: 2018-07-02

Volume: Unknown

Issue: Unknown

Page Range: 411-416

Description:

In this paper we propose a soft computing-based solution to assess multivariate prediction ability in legal decision-making process. The proposed method is capable of incorporating prior knowledge. The main goal is, automatizing legal decision making, which is complex, complicated and often characterized by broad vigilance. The aim is helping legal practitioners to be able to focus not only on the decision itself, rather the correlations between them and combining of their variations as well. This way a "hybrid" thinking would be performed. The system will be able to "think through" a great number of possible variations of decisions and their combinations synchronized with the speed of the human mind.

Open Access: Yes

DOI: 10.1109/CogInfoCom.2018.8639868

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