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Found 6319 publications

Mathematics and computational intelligence synergies for emerging challenges

Eloísa Ramírez-Poussa Juan Moreno-García Ĺaszĺo T. Ḱoczy Jesús Medina-Moreno

Publication Name: International Journal of Computational Intelligence Systems

Publication Date: 2021-01-01

Volume: 14

Issue: 1

Page Range: 818-820

Description:

No description provided

Open Access: Yes

DOI: 10.2991/ijcis.d.210121.001

Hawkes processes: some key ideas, links to neuroscience and system identification

Dániel Fabó György Perczel Loránd Erőss Zsuzsanna Vágó László Gerencsér

Publication Name: Communications in Information and Systems

Publication Date: 2021-01-01

Volume: 21

Issue: 3

Page Range: 385-413

Description:

The primary objective of the present paper is to provide a brief survey of basic ideas and some key results of the theory of Hawkes processes that may serve as an interface for multidisciplinary research between mathematics and neurosciences, with hints to epidemiology. The class of Hawkes processes is considered as an appropriate model to describe the pattern of neuronal firing, see [56] [38]. As such, it is a prime candidate for detecting changes in brain activity, and consequently to predict epileptic seizures. Most of the advanced results will be presented via simple examples. In addition, we elaborate on links between the theory of Hawkes processes and linear stochastic systems, in particular system identification. A few new results in this context will be also presented with the outline of their proofs.

Open Access: Yes

DOI: 10.4310/cis.2021.v21.n3.a4

Numerical Simulation of Coupled Electromagnetic and Thermal Problems in Permanent Magnet Synchronous Machines

Lotfi Abdelhakim Daniel Marcsa V. Chabannes C. Prudhomme Zoltán Horváth

Publication Name: Lecture Notes in Computational Science and Engineering

Publication Date: 2021-01-01

Volume: 139

Issue: Unknown

Page Range: 693-701

Description:

The main objective of our task is to develop mathematical models, numerical techniques to analyse the thermal effects in electric machines, to implement the developed algorithm in multiprocessor or multi-core environments and to apply them to industrial use cases. In this study, we take into account coupled character of the electromagnetic and thermal features of the physical process. Both thermal and electromagnetic processes are considered transient, solved by means of the FEM method on independent meshes and the time-discretization is realized using time operator splitting. Two examples are presented to assess the accuracy of the developed coupled solvers and the numerical results are compared with the experimental ones, which are obtained from a prototype machine.

Open Access: Yes

DOI: 10.1007/978-3-030-55874-1_68

DAIRY WASTEWATER UTILIZATION BY COMBINATION OF OXIDATION PRE-TREATMENT AND ULTRAFILTRATION

Zsuzsanna László Sándor Beszédes E. Lakatos Mihály Zakar Gábor Keszthelyi-Szabó

Publication Name: Environmental Engineering and Management Journal

Publication Date: 2021-01-01

Volume: 20

Issue: 12

Page Range: 1711-1719

Description:

In this work the effects of oxidation pre-treatments (ozonation and Fenton reaction) on membrane filtration of dairy wastewater were investigated, together with the further utilization possibilities of residual wastes. The oxidation pre-treatments enhanced the membrane filtration efficiency, from which the short-term ozone treatment was found to be the most effective method both in terms of increasing the flux and the pollutant removal efficiency. After ozone pre-treatment the phosphate and ammonium content of the wastewater migrated to the permeate, while after Fenton pre-treatment the phosphate content remained in the concentrate, and the ammonium content in the permeate decreased. The concentrate was utilized as biogas resource and it was found that both pretreatments increased the biogas production and its methane content as well. Based on our results it can be concluded that ozone pretreatment combined with membrane separation have improved the efficiency of dairy wastewater treatment and may suit the requirements of circular economy.

Open Access: Yes

DOI: DOI not available

Welding distortion generated uncertainties in the vibrational behavior of a ladder-like structure

Dániel Feszty Marcell Treszkai David Sipos

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:

Recent developments in acoustic simulation methods allowed engineers to assess the vibroacoustic behavior of various type of structures within a virtual environment, thus allowing the replacement of prototype-based development with simulations. However, there are some factors, that cannot be considered in simulations in advance. In the present study, the effect of the distortions generated due to welding on a ladder-like structure equipped with flat plates was investigated. The measured acceleration frequency response functions were compared to finite element simulation results. The measured responses differed significantly from the simulation, even in the low frequency ranges, where the global modes were not expected to be altered or vanished. Investigation of the simulated results revealed that the additional modes were related to the vibration of the plates, which were assumed to be flat, instead of considering the warping caused by the welding process. After measuring the approximate deformation of the plates, an updated simulation model was made, introducing an approximate curvature in them. The results obtained with the updated simulation model performed much better in the low frequency range as well as in the third octave-averaged frequency bands up 1200 Hz. The sensitivity of the warping was also systematically evaluated.

Open Access: Yes

DOI: 10.3397/IN-2021-2844

Co-composting with herbal wastes: Potential effects of essential oil residues on microbial pathogens during composting

E. Lakatos Babett Greff Jenő Szigeti László Varga

Publication Name: Critical Reviews in Environmental Science and Technology

Publication Date: 2021-01-01

Volume: 51

Issue: 5

Page Range: 457-511

Description:

Because of the increasing use of herbal essential oils (EO) in pharmacology, medicine, and food processing, global EO production grows at a rapid rate, generating large amounts of plant residues worldwide. The use of herbal residues for co-composting with various wastes offers a novel option for eco-friendly and cost effective waste management. However, the biologically active compounds remaining in the herb residues may affect microbial activity in the composting biomass, thereby influencing final compost quality. In this review, we summarize and evaluate current literature on the occurrence and survival of pathogens in composts, the beneficial effects of using herbal residues as bulking agents, and the potential antipathogenic effects of six herb species belonging to the Lamiaceae family as follows: lemon balm (Melissa officinalis L.), oregano (Origanum vulgare L.), lavender (Lavandula angustifolia Mill.), rosemary (Rosmarinus officinalis L.), thyme (Thymus vulgaris L.), and sage (Salvia officinalis L.).

Open Access: Yes

DOI: 10.1080/10643389.2020.1732780

Correspondences between Hungarian women's marital names and the traditional family schema

Judit Baranyiné Kóczy

Publication Name: Cognitive Linguistic Studies in Cultural Contexts

Publication Date: 2021-01-01

Volume: 14

Issue: Unknown

Page Range: 151-183

Description:

A marital name makes a statement about women's cultural values with respect to their family schemas. In Hungary, adopting the husband's full name by marriage is no longer required, thus women have the opportunity to choose from seven different name structures. The paper aims to uncover the motivations behind women's preference for marital name structures as influenced by the traditional family schema that they maintain in their background. Data for this analysis is extracted from a questionnaire distributed to 533 women, which seek to obtain information on key elements of the traditional family schema. Results do not reveal a direct correlation between the selection of marital names and any single component of the traditional family schema; however, overall the results of the survey outline a systematic correspondence between marital names and women's conformity or non-conformity to the traditional family schema. In conclusion, the various marital name structures reflect diverse family schemas, in particular, they are representatives of Hungarian women's different extent of adherence to the traditional family schema.

Open Access: Yes

DOI: 10.1075/clscc.14.08koc

Understanding intentions towards seeking university-business partnerships – analysing four european cases

Zsolt Kohus Katalin Czakó Zoltán Baracskai

Publication Name: Journal of International Studies

Publication Date: 2021-01-01

Volume: 14

Issue: 2

Page Range: 228-244

Description:

It is an important economic and social issue for universities to provide value for their communities by seeking and maintaining partnerships with local firms. This paper analyses institutions of different national economies. It systematises the differences and similarities in the communication of universities aiming to partnering. To this end, we present four European cases from France, Germany, Hungary and Poland. The methodology lies in its grounded theory approach to a continuous multi-case analysis. Our hypotheses are as follows: There are role differences of universities in the observed cases (H1). There are different understandings behind fruitful university-business partnerships (H2). The rate of diversification in local industries effects the presence and types of university services and business partnering activity (H3). Data hubs were extracted from institutional communications and integrated with local economic data input. The novel approach of applying the grounded theory supports complex observation. Notions of fruitful partnerships are institution-specific, but we identify two opposite perspectives of strategies to run efficient university-business partnering. The structure of the local industrial environment, research output and university-business interactions have definable mutual effects.

Open Access: Yes

DOI: 10.14254/2071-8330.2021/14-2/15

NVH characterization of a ladder-like welded structure using finite element analysis and experimental method

Dániel Feszty Balázs Vehovszky Attila Schweighardt

Publication Name: Advances in Acoustics Noise and Vibration 2021 Proceedings of the 27th International Congress on Sound and Vibration Icsv 2021

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In vehicle industry, considering a chassis, the evaluation of the experimental modal analysis is usually done up to 80 Hz, since the modal density is increasing with frequency. In addition, the deviation between the measurement and simulation is getting more significant at higher frequencies. The purpose of this study is to extend the usable test range and to improve the accuracy of the results both in case of measurement and FE (Finite Element) simulation. Present paper introduces the vibrational characterization of a ladder-like welded structure. This test case represents a simplified model of a vehicle's frame consisting of rod-like elements with high stiffness, connected to each other in welded junctions. Although such simulational and experimental modal analysis procedures are widely used in practice, results can significantly change according to the used method and the fine-tuning of parameters. For this reason, a further goal is to find the best measurement and simulation technique for the given structure. During the FE analysis different modelling solutions and element types were compared. In order to discover the effect of the manufacturing inaccuracies, the same measurements were performed on two distinct, but theoretically identical samples. The influence of the experimental setup (e.g. excitation and fixing method) and settings were investigated as well. Finally, FE simulation and experimental results are compared using Frequency Response Functions.

Open Access: Yes

DOI: DOI not available