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Publications - 6278

FPGA based acceleration of computational fluid flow simulation on unstructured mesh geometry

Csaba Nemes Antal Hiba Zoltán Nagy András Kiss Árpád Csík Péter Szolgay

Publication Name: Proceedings 22nd International Conference on Field Programmable Logic and Applications Fpl 2012

Publication Date: 2012-12-12

Volume: Unknown

Issue: Unknown

Page Range: 128-135

Description:

Numerical simulation of complex computational fluid dynamics problems evolving in time plays an important role in scientific and engineering applications. Accurate behavior of dynamical systems can be understood using large scale simulations which traditionally requires expensive super-computing facilities. In the paper a Field Programmable Gate Array (FPGA) based framework is described to accelerate simulation of complex physical spatio-temporal phenomena. Simulating complicated geometries requires unstructured spatial discretization which results in irregular memory access patterns severely limiting computing performance. Data locality is improved by mesh node renumbering technique which results in a sequential memory access pattern. Additionally storing a small window of cell-centered state values in the on-chip memory of the FPGA can increase data reuse and decrease memory bandwidth requirements. Generation of the floating-point data path and control structure of the arithmetic unit containing dozens of operators is a very challenging task when the goal is high operating frequency. Efficiency and use of the framework is described by a case study solving the Euler equations on an unstructured mesh using finite volume technique. On the currently available largest FPGA the generated architecture contains three processing elements working in parallel providing 75 times speedup compared to a high performance microprocessor. © 2012 IEEE.

Open Access: Yes

DOI: 10.1109/FPL.2012.6339276

Identification of Delay-Tolerant Networking by Employing MABAC Technique Based on Bipolar Complex Fuzzy Dombi Heronian Mean Operators

Dragan Pamucar Tahir Mahmood None Azam Ubaid Ur Rehman

Publication Name: Contemporary Mathematics Singapore

Publication Date: 2025-01-01

Volume: 6

Issue: 3

Page Range: 3562-3612

Description:

This work proposes a hybrid decision making model for dynamic and irregularly connected communication systems called Delay-Tolerant Networks (DTNs). A resilient and adaptable network allows for communication in an environment where traditional networks may fail to operate effectively. The main significance of this system is that it is commonly utilized in such scenarios where traditional networks are impractical, such as remote areas, disaster-stricken regions, space missions, and military operations. The proposed model includes the “Multi-Attributive Border Approximation Area Comparison” (MABAC) method, together with Bipolar Complex Fuzzy Dombi Heronian Mean (BCFDHM) operators. To take the positive as well as negative attributes’ evaluations into consideration in complicated fuzzy environments, we use an enriched aggregation structure for the criteria, which incorporates the relationship between criteria through the Heronian mean function. Due to this, the MABAC technique within BCF information is more advanced and better than classical MABAC techniques in various models. After that, with the help of these enriched aggregation structures, we successfully identify and rank alternatives for DTN in an uncertain, imprecise, and bipolar condition. By employing the MABAC technique for the DTN system, we find the best and better alternative to the DTN system, which is Ã4 as mentioned below in section 4. At last, we compare our initiated work with many existing theories to prove the authenticity of the suggested work.

Open Access: Yes

DOI: 10.37256/cm.6320256840

Joint audit work allocation in the mandatory joint audit setting: a comparative study between the developed and the emerging economies

Árpád Tóth Katalin Borbély Mohammed Ibrahem Ali Hassan

Publication Name: Cogent Business and Management

Publication Date: 2026-01-01

Volume: 13

Issue: 1

Page Range: Unknown

Description:

This study investigates the effects of joint audit work allocation on audit quality, fees, and report delays. It analyzes data from 347 non-financial listed firms in France and Morocco. Audit fee shares serve as a proxy for workload distribution. The findings reveal notable differences between France and Morocco. At the macro level, there is no statistically significant relationship between joint audit work allocation and either audit quality or audit report delays in France. However, greater imbalances in work allocation are associated with higher audit fees. In Morocco, greater imbalances in the allocation of work are associated with lower audit quality, higher fees, and longer delays. At the joint audit pair level, most pairs in both countries exhibit no significant relationship between work allocation and audit quality, fees, or report delays. Nevertheless, specific French and Moroccan pairs with greater imbalances in work allocation experience higher audit fees and longer delays. Regarding company size, joint audit work allocation has a minimal effect on audit quality, fees, and delays among large firms. As unbalanced joint audits have parallels to single audits, our findings contribute to current discussions of their comparative advantages and disadvantages. This study provides valuable and practical insights for a wide audience, including investors, board members, practitioners, academics, and policymakers.

Open Access: Yes

DOI: 10.1080/23311975.2026.2640254

On the relationships between the first and second Zagreb Indices

Tamás Réti

Publication Name: Match

Publication Date: 2012-12-01

Volume: 68

Issue: 1

Page Range: 169-188

Description:

The Zagreb indices introduced by Gutman and Trinajstić more than thirty years ago are graph-based molecular structure descriptors. The research and application of the Zagreb indices appears mainly in mathematical chemistry. In this paper we present some new inequalities related to the first and the second Zagreb indices. By introducing the notions of P-dominant graphs, and of the valency-functions of a graph, correspondences with the novel inequalities presented are discussed. In addition, we find examples characterizing the validity of Zagreb indices inequality and equalities for some particular classes of connected biregular graphs.

Open Access: Yes

DOI: DOI not available

Uncertainty representation in nonlinear and hybrid systems

Peter Varlaki Annamária R. Várkonyi-Kóczy

Publication Name: Iccc 2005 IEEE 3rd International Conference on Computational Cybernetics Proceedings

Publication Date: 2005-12-01

Volume: 2005

Issue: Unknown

Page Range: 313-318

Description:

Information of any kind always involve some kind of uncertainty, inaccuracy. The model used to represent the information during the information processing can affect the achievable preciseness and can determine the usability of different computing methods, as well. The data model must also be able to represent the uncertainty, inaccuracy of both the input data and the results. The two most popular data models for the representation of uncertain data are the "classical", probability based and the recently introduced fuzzy data model. With the increasing complexity of the computing problems and with the appearance and spreading of new modeling and computing techniques, the evaluation and representation of the uncertainty in different systems become an increasingly important question and methods for the mixed use of different data models can also be needed. This paper deals with the limits of the "classical", probability theory based uncertainty representation and examines possible solutions for information processing based on mixed data models together with different conversion methods between fuzzy and probability theory based representations.

Open Access: Yes

DOI: 10.1109/ICCCYB.2005.1511593

A New Type of Motor Topology for Reducing the Torque Ripples in Synchronous Reluctance Motor Drives of Electric Vehicles

István Szászi Tibor Vajsz Csongor Horváth Richárd Csaba Kovács Vilmos Paiss István Szászi

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1258 LNNS

Issue: Unknown

Page Range: 528-540

Description:

Electric vehicle applications are one of the most popular topics in the case of electric motor research & development activities. Novel types of electric motor solutions, offering new advantages are gaining significant attention today. Synchronous reluctance motors (SynRMs) have several advantages that are particularly useful in the case of electric vehicle applications. Their lower costs, their robust buildup and their excellent efficiency are all features that are greatly desired in the case of electric mobility applications. However, SynRMs are well known in the literature for producing more torque ripples with the conventional torque control methods. One way to reduce the torque ripples is to use advanced torque control algorithms. The other way is to use optimized motor topologies with the conventional torque control algorithms. The paper aims at the investigation of the motor design concepts that could be applied for reducing the torque ripples of a SynRM drive. It will be analyzed whether the typical relationships and concepts that are used for minimizing the torque ripples in the case of a PMSM can also be applied for a SynRM or not. Simulations will be carried out in JMAG environment to validate the new concepts. The reduced amount of the torque ripples leads to a less amount of audible noise, which can be an advantage in the case of certain electric vehicle applications and for certain customers.

Open Access: Yes

DOI: 10.1007/978-3-031-81799-1_48

Omega-3 Fatty Acid Consumption Alters Uterine Contraction: A Comparative Study on Different Breeds of Rats

Tamás Tóth George Bázár Reza Samavati Kalman F. Szucs Annamaria Schaffer Dora Vigh Henrik Baranyay Seyedmohsen Mirdamadi Tamara Barna Róbert Gáspár

Publication Name: International Journal of Molecular Sciences

Publication Date: 2025-06-01

Volume: 26

Issue: 11

Page Range: Unknown

Description:

Polyunsaturated fatty acids (PUFAs) play roles in several physiological and pathophysiological processes, but their effects on reproductive function are controversial. The aim of the study was to investigate the effect of n-3 PUFA-rich fish oil and n-6-rich sunflower oil on sex hormone status, in vivo and in vitro uterine contractility, and endometrial remodeling. Female Sprague Dawley, Lister hooded, and Wistar rats were treated orally for 20 days with 1 mL of tap water, sunflower oil, or fish oil. Blood samples were taken for gonadotropic and sex hormone analysis. In vivo smooth muscle contractions were measured weekly by electromyography. Isolated uterine and cecal contractions were measured after sacrificing the animals. Endometrial remodeling was detected based on the presence of αvβ3 integrin by optical imaging. In Sprague Dawley rats, fish oil increased the LH level and progesterone/estradiol (P4/E2) ratio compared to the sunflower oil-treated group. Uterine contractions were reduced both in vitro and in vivo. Endometrial αvβ3 integrin activity was increased in the fish oil group. In Lister hooded rats, neither sunflower nor fish oil treatments modified the investigated parameters. However, in Wistar rats, both oils increased only the in vivo contractions and reduced the P4/E2 ratio, along with αvβ3 integrin fluorescence. n-3 PUFA-rich fish oil induces a breed-dependent effect on sex hormone status and uterine contractions in rats. The response to PUFA intake may vary significantly within a given species, which may have importance both in animal feeding and human nutrition.

Open Access: Yes

DOI: 10.3390/ijms26115221

Developing sustainable logistic strategies in the context of cognitive biases

Peter Foldesi Eszter Sós

Publication Name: Infocommunications Journal

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 110-118

Description:

Cognitive biases often occur even in the decision-making process of highly qualified company managers due to the drive for efficiency and time pressure in operations. At the same time, there are also long-term strategic decisions where time pressure is no longer a factor, and yet cognitive bias appears, which has to be considered properly. In strategic issues, decision- makers tend to see their wishes and desires rather than the objective reality. The proposed system of fuzzy indicators based on technical and objective data supports decision-making between logistics strategies by mitigating cognitive biases, which is extremely important in the logistics field, where the decisions have to be made partly based on subjective, vague, or uncertain parameters.

Open Access: Yes

DOI: 10.36244/ICJ.2024.5.13

Reconstructing the Definition of Space Debris

Gábor Sulyok Mónika Ganczer

Publication Name: Air and Space Law

Publication Date: 2025-12-01

Volume: 50

Issue: 6

Page Range: 537-558

Description:

The international community has realized that space debris is a global concern that should be addressed with a sense of urgency. Keeping in mind the limitations of the prevailing normative framework, the optimal solution would be to address the problem by way of universal lawmaking. However, any universal lawmaking effort presupposes the creation of a uniform definition of space debris. Non-binding international standards and national documents currently contain a variety of definitions. The coexistence of divergent definitions may lead to fragmentation and legal uncertainty, and their restrictive approach may become untenable as humankind ventures deeper into outer space. Based upon these considerations and adopting a proactive mindset, the present paper aims to re-evaluate the prevailing definitions with a view to proposing a comprehensive, feasible and durable definition covering all extant and future forms of space debris. The analysis commences with an overview of selected universal, regional and national definitions. This is followed by the identification, reassessment and possible revision of shared elements of the definitions concerned. The reassessed and revised elements are then assembled to propose a new definition to contribute to the ongoing discussion on space debris.

Open Access: Yes

DOI: 10.54648/aila2025059