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Publications - 6374

Evaluating the Return Volatility of Cryptocurrency Market: An Econometrics Modelling Method

Laszlo Vasa Ashutosh Kolte Avinash Pawar Jewel Kumar Roy Imre Vida

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2022-01-01

Volume: 19

Issue: 5

Page Range: 107-126

Description:

Cryptocurrency is the blockchain financial technology used for transactions in financial institutions and exchanges. Bitcoin has attracted much coverage from investors and commentators as it represents the maximum market capitalization on a crypto-currency exchange. The study aims to determine the correlation between the daily log–returns and to understand the tendencies in the cryptocurrency market instability of Bitcoin, Litecoin, XRP, Nxt, Dogecoin, Vertcoin, DigiByte, DASH, Counterparty, and MonaCoin. The correlation among the selected cryptocurrencies exists in the study. The analysis is focused primarily upon reference information from the preserved servers of cryptocurrency websites and finance.yahoo.com. This research assesses regular details on the Logarithmic return of Bitcoin, Litecoin, XRP, Nxt, Dogecoin, Vertcoin, DigiByte, DASH, Counterparty, and MonaCoin for a timeframe spanning from October 01st, 2014, to April 30th, 2020. From 131 cryptocurrencies, we considered only 10 Cryptocurrencies due to the availability of data after October 2014. Where there was insufficient information, there were average results determined from preceding and succeeding data. Findings demonstrate that there is GARCH modelling of cryptocurrencies against Bitcoin. Litecoin, XRP, Nxt, Dogecoin, Vertcoin, DigiByte, DASH, Counterparty, and MonaCoin; variability values throughout the duration had a significant effect on the updates from Bitcoin returns. We believe that it helps create information and resources that are valuable to practitioners and scholars who research and form cryptocurrency markets in the future.

Open Access: Yes

DOI: 10.12700/APH.19.5.2022.5.6

A multipole expansion technique in solving boundary integral equations

Csaba Gáspár

Publication Name: Computer Methods in Applied Mechanics and Engineering

Publication Date: 1998-05-11

Volume: 157

Issue: 3-4

Page Range: 289-297

Description:

The Boundary Integral Equation Method reduces the spatial dimension of an elliptic problem by converting the original n-dimensional partial differential equation to an (n - 1)-dimensional boundary integral equation defined on the boundary of the domain of the original problem. At the same time, the discretisation of the problem is also remarkably simplified. The price of these advantages, however, is that the structure, as well as the algebraic properties of the resulting boundary element matrices, are somewhat unpleasant, since they are neither sparse nor self-adjoint in general, even if the original problem is self-adjoint. Consequently, the computational cost of the Boundary Integral Equation Method seems to be unnecessarily high. To make the method more economic from a computational point of view, we present a numerical technique based on the multipole expansion method, which reduces the computational cost of the appearing matrix-vector multiplications (i.e. the evaluations of the discretized boundary integrals) by a remarkable amount. The method is applicable also to die reconstruction problem, when the inner solution is to be reconstructed from the boundary solutions. © 1998 Elsevier Science S.A.

Open Access: Yes

DOI: 10.1016/S0045-7825(97)00241-7

Fuzzy Situational Maps: A new approach in mobile robot cooperation

Claudiu Radu Pozna Áron Ballagi Peter Foldesi Laszlo T. Koczy

Publication Name: Ines 2013 IEEE 17th International Conference on Intelligent Engineering Systems Proceedings

Publication Date: 2013-12-12

Volume: Unknown

Issue: Unknown

Page Range: 287-292

Description:

Intelligent robot cooperation tasks have very complex decision-making and computational processes. Collecting and calculating with a high amount of data is one of the weakest point of such system. In addition all of these it is necessary to process in real-time with limited computational capacity. In this paper we propose some novel algorithms for coping with these problems and give some information about the Fuzzy Situational Maps as a special case of the Fuzzy Signatures. An example takes to the field of warehouse logistics, managing and arranging boxes will be presented. © 2013 IEEE.

Open Access: Yes

DOI: 10.1109/INES.2013.6632828

Kalman filter for mobile-robot attitude estimation: Novel optimized and adaptive solutions

Péter Odry Akos Odry Imre J. Rudas Robert Fuller

Publication Name: Mechanical Systems and Signal Processing

Publication Date: 2018-09-15

Volume: 110

Issue: Unknown

Page Range: 569-589

Description:

This paper proposes two novel approaches to estimate accurately mobile robot attitudes based on the fusion of low-cost accelerometers and gyroscopes. The first part of the paper demonstrates the use of a special test bench that both enables simulations of various dynamic behaviors of wheeled robots and measures their real attitude angles along with the raw sensor data. These measurements are applied in a simulation environment and we outline an offline optimization of Kalman filter parameters. The second part of the paper introduces a novel adaptive Kalman filter structure that modifies the noise covariance values according to the system dynamics. The instantaneous dynamics are characterized regarding the magnitudes of both the instantaneous vibration and the external acceleration. The proposed adaptive solution measures these magnitudes and utilizes fuzzy-logic to modify the filter parameters in real time. The results show that the adaptive filter improves the overall filter convergence by a remarkable 10.9% over using the optimized Kalman filter, thereby demonstrating its efficacy as an accurate and robust attitude filter. The proposed filter performances are also benchmarked against other common methods indicating that the flexibility of the developed adaptive filter allowed it to compete and even outperform the benchmark filters.

Open Access: Yes

DOI: 10.1016/j.ymssp.2018.03.053

Discrete bacterial memetic evolutionary algorithm for the time dependent traveling salesman problem

Peter Foldesi Boldizsar Tuu-Szabo Laszlo T. Koczy

Publication Name: Communications in Computer and Information Science

Publication Date: 2018-01-01

Volume: 853

Issue: Unknown

Page Range: 523-533

Description:

The Time Dependent Traveling Salesman Problem (TDTSP) that is addressed in this paper is a variant of the well-known Traveling Salesman Problem. In this problem the distances between nodes vary in time (are longer in rush hours in the city centre), Our Discrete Bacterial Evolutionary Algorithm (DBMEA) was tested on benchmark problems (on bier127 and on a self-generated problem with 250 nodes) with various jam factors. The results demonstrate the effectiveness of the algorithm.

Open Access: Yes

DOI: 10.1007/978-3-319-91473-2_45

Curated Vibration Features and an Interpretable Gearbox Health Index (GHI) Baseline for Condition Monitoring Bench-Marking

Krisztian Horvath Krisztián Horváth

Publication Name: Data

Publication Date: 2026-04-01

Volume: 11

Issue: 4

Page Range: Unknown

Description:

This data descriptor provides a standardized and reproducible subsystem-level representation of the NREL wind turbine gearbox condition monitoring benchmarking dataset. The released records are derived from Healthy (H1–H10) and Damaged (D1–D10) measurement files and include subsystem-level standardized indices (KHI_HS, KHI_IMS, KHI_PL) together with a calibrated 0–1 Gearbox Health Index (GHI). The indices are generated using a fully specified and deterministic feature extraction and aggregation workflow based on established vibration indicators and healthy-referenced normalization. The Zenodo deposit contains machine-readable CSV tables intended to support transparent benchmarking across supervised classification and anomaly detection studies. The proposed GHI is introduced as an interpretable and reproducible reference baseline rather than an optimized diagnostic model. Technical validation demonstrates condition-level separability within the analyzed dataset while emphasizing the descriptive nature of the index. By releasing structured derived records and a documented regeneration procedure, this work enables an implementation-independent comparison of gearbox condition monitoring approaches and supports reproducible evaluation of alternative health index formulations. Dataset: 10.5281/zenodo.18832721. Dataset License: Creative Commons Attribution 4.0 International (CC-BY 4.0)

Open Access: Yes

DOI: 10.3390/data11040070

Complex Test Scenarios for Functional Validation Prior to Type Approval

Balint Toth Leticia Pekk

Publication Name: Future Transportation

Publication Date: 2026-02-01

Volume: 6

Issue: 1

Page Range: Unknown

Description:

The continuous tightening of European regulatory requirements, particularly under the General Safety Regulation (GSR), has considerably increased the scope and cost of proving ground testing required for the validation of Advanced Driver Assistance Systems (ADASs) and Automated Driving Systems (ADSs). This study presents a methodology for constructing complex proving ground test scenarios aimed at supporting early-stage functional validation and cost-efficient preparation for type approval. The method is based on the systematic analysis of proving ground–relevant ADAS regulations and the classification of test case variations according to sensing, actuation, and execution complexity. By filtering and combining representative test cases, minimum and maximum complexity scenarios were developed and evaluated on the ZalaZONE proving ground in Hungary. The results demonstrate that the proposed approach can substantially reduce test duration, facility occupancy, and overall validation costs, while maintaining the representativeness and credibility of results. Beyond cost savings, the methodology offers a scalable and practical framework for physical validation, supporting manufacturers in achieving regulatory compliance with reduced time and expenditure.

Open Access: Yes

DOI: 10.3390/futuretransp6010001

Modeling of the Dynamic Rail Deflection using Elastic Wave Propagation

Szabolcs Fischer Dmytro Kurhan

Publication Name: Journal of Applied and Computational Mechanics

Publication Date: 2022-01-01

Volume: 8

Issue: 1

Page Range: 379-387

Description:

There is a class of tasks that requires considering the dynamics not only for rolling stock but also for the response of the railway track. One of the directions of railway transport development, which encourages the transition to fundamentally newdynamic models of the railway track, is undoubtedly an increase in traffic speed. To solve such problems, the authors applied amodel of the stressed-strained state of a railway track based on the dynamic problem of elasticity theory. The feature of this modelis the calculation of dynamic stresses and deformations induced by the spread of elastic waves through the objects of the railwaytrack. Based on the mathematical modeling of stress propagation in the under-rail basis, authors have shown the influence ofvarious objects of a railway track on the formation of the outline of the front of the elastic wave and determined the main timeintervals. Furthermore, the authors propose the following analytical method, which, in addition to the soil's physical andmechanical properties, considers the properties of the ballast as a layer that transmits pressure to the roadbed and takes an activepart in the formation of the interaction space

Open Access: Yes

DOI: 10.22055/jacm.2021.38826.3290

Viability of bifidobacteria in soft-frozen ice cream supplemented with a Saccharomyces cerevisiae cell wall product

T. Andok László Varga

Publication Name: Acta Alimentaria

Publication Date: 2018-09-01

Volume: 47

Issue: 3

Page Range: 387-392

Description:

The purpose of this research was to monitor the changes during storage in survival of bifidobacteria in a soft-frozen ice cream supplemented with a yeast cell wall-based product claimed to contribute to the functioning of the immune system. An ice cream mix was prepared and pasteurised. After overnight aging at 4 °C, it was inoculated with Bifidobacterium animalis subsp. lactis Bb-12. Two batches of the mix were supplemented with a commercial Saccharomyces cerevisiae cell wall product at 2.0% and 4.0% (w/w), whereas a third batch was left unsupplemented and served as control. The final mixes were frozen, and the three products were stored at –13 °C for 7 days. The ice creams contained viable bifidobacteria cells at levels exceeding 106 CFU g–1 throughout the storage period. Although the yeast supplement decreased the loss of viability of bifidobacteria during frozen storage of ice creams, it imparted a slightly bitter off-flavour to the samples and it also negatively influenced the original white colour of the product, thereby necessitating further work to develop flavoured varieties of the Saccharomyces cell wall-containing synbiotic ice cream.

Open Access: Yes

DOI: 10.1556/066.2018.47.3.15